Seminário proferido pelo pesquisador Thiago Burgo (Unicamp) em 26 de agosto de 2015 para cerca de 20 estudantes e professores, na seção UCS (Caxias do Sul, RS) do Instituto Nacional de Engenharia de Superfícies.
Invited lecture of the Simposium N "Surface Engineering - functional coatings and modified surfaces" at the XIII SBPMat (Brazilian MRS) meeting, in João Pessoa (Brazil). The lecture took place on September 29th, 2014.
The speaker was Tiberiu Minea, Professor at Université Paris-Sud (France), President of the French Federation of Scientific Societies and President of the Scientific and Technical Committee at the French Vacuum Society.
Los días 22 y 23 de junio de 2016 organizamos en la Fundación Ramón Areces un simposio internacional sobre 'Materiales bidimensionales: explorando los límites de la física y la ingeniería'. En colaboración con el Massachusetts Institute of Technology (MIT), científicos de este prestigioso centro de investigación mostraron las propiedades únicas de materiales como el grafeno, de solo un átomo de espesor, y al mismo tiempo más resistente que el acero y mucho más ligero.
In-situ TEM studies of tribo-induced bonding modification in near-frictionles...Deepak Rajput
A presentation on "In-situ TEM studies of tribo-induced bonding modification in near-frictionless carbon films" made by Deepak Rajput. This presentation was based on "critical review of a paper," in All Things Carbon course offered at the University of Tennessee Space Insitute at Tullahoma in Fall 2009.
Los días 22 y 23 de junio de 2016 organizamos en la Fundación Ramón Areces un simposio internacional sobre 'Materiales bidimensionales: explorando los límites de la física y la ingeniería'. En colaboración con el Massachusetts Institute of Technology (MIT), científicos de este prestigioso centro de investigación mostraron las propiedades únicas de materiales como el grafeno, de solo un átomo de espesor, y al mismo tiempo más resistente que el acero y mucho más ligero.
This document summarizes an ARPES and SPE-LEEM study on supported, suspended, and twisted bilayer MoS2. The study directly measures the MoS2 band structure using SPE-LEEM to study the band gap transition and role of interlayer coupling in monolayer, bilayer, and twisted bilayer MoS2. It also studies the substrate effect by examining suspended MoS2. Preliminary results on effective mass and spin-orbit splitting are also presented.
Los días 22 y 23 de junio de 2016 organizamos en la Fundación Ramón Areces un simposio internacional sobre 'Materiales bidimensionales: explorando los límites de la física y la ingeniería'. En colaboración con el Massachusetts Institute of Technology (MIT), científicos de este prestigioso centro de investigación mostraron las propiedades únicas de materiales como el grafeno, de solo un átomo de espesor, y al mismo tiempo más resistente que el acero y mucho más ligero.
The document provides an overview of Hajo Freund's research on modeling heterogeneous catalysts at the atomic level. It discusses four conceptual studies: (1) investigating the active sites at metal-oxide interfaces in supported nanoparticle systems using scanning tunneling microscopy, (2) modeling amorphous silica supports through thin film preparation, characterization, and scanning probe microscopy, (3) examining adsorption and chemical reactions in confined spaces using infrared absorption spectroscopy, and (4) understanding the influence of morphology on reactivity through carbon dioxide activation studies. The research aims to develop molecular-scale models of heterogeneous catalysts through advanced surface science techniques.
Invited lecture of the Simposium N "Surface Engineering - functional coatings and modified surfaces" at the XIII SBPMat (Brazilian MRS) meeting, in João Pessoa (Brazil). The lecture took place on September 29th, 2014.
The speaker was Tiberiu Minea, Professor at Université Paris-Sud (France), President of the French Federation of Scientific Societies and President of the Scientific and Technical Committee at the French Vacuum Society.
Los días 22 y 23 de junio de 2016 organizamos en la Fundación Ramón Areces un simposio internacional sobre 'Materiales bidimensionales: explorando los límites de la física y la ingeniería'. En colaboración con el Massachusetts Institute of Technology (MIT), científicos de este prestigioso centro de investigación mostraron las propiedades únicas de materiales como el grafeno, de solo un átomo de espesor, y al mismo tiempo más resistente que el acero y mucho más ligero.
In-situ TEM studies of tribo-induced bonding modification in near-frictionles...Deepak Rajput
A presentation on "In-situ TEM studies of tribo-induced bonding modification in near-frictionless carbon films" made by Deepak Rajput. This presentation was based on "critical review of a paper," in All Things Carbon course offered at the University of Tennessee Space Insitute at Tullahoma in Fall 2009.
Los días 22 y 23 de junio de 2016 organizamos en la Fundación Ramón Areces un simposio internacional sobre 'Materiales bidimensionales: explorando los límites de la física y la ingeniería'. En colaboración con el Massachusetts Institute of Technology (MIT), científicos de este prestigioso centro de investigación mostraron las propiedades únicas de materiales como el grafeno, de solo un átomo de espesor, y al mismo tiempo más resistente que el acero y mucho más ligero.
This document summarizes an ARPES and SPE-LEEM study on supported, suspended, and twisted bilayer MoS2. The study directly measures the MoS2 band structure using SPE-LEEM to study the band gap transition and role of interlayer coupling in monolayer, bilayer, and twisted bilayer MoS2. It also studies the substrate effect by examining suspended MoS2. Preliminary results on effective mass and spin-orbit splitting are also presented.
Los días 22 y 23 de junio de 2016 organizamos en la Fundación Ramón Areces un simposio internacional sobre 'Materiales bidimensionales: explorando los límites de la física y la ingeniería'. En colaboración con el Massachusetts Institute of Technology (MIT), científicos de este prestigioso centro de investigación mostraron las propiedades únicas de materiales como el grafeno, de solo un átomo de espesor, y al mismo tiempo más resistente que el acero y mucho más ligero.
The document provides an overview of Hajo Freund's research on modeling heterogeneous catalysts at the atomic level. It discusses four conceptual studies: (1) investigating the active sites at metal-oxide interfaces in supported nanoparticle systems using scanning tunneling microscopy, (2) modeling amorphous silica supports through thin film preparation, characterization, and scanning probe microscopy, (3) examining adsorption and chemical reactions in confined spaces using infrared absorption spectroscopy, and (4) understanding the influence of morphology on reactivity through carbon dioxide activation studies. The research aims to develop molecular-scale models of heterogeneous catalysts through advanced surface science techniques.
The document reports on an ARPES microscopy study of free-standing bilayer graphene. Key findings include:
1) Bilayer graphene samples were prepared by mechanical exfoliation on 5μm wells and studied using ARPES microscopy between 110-300K.
2) Analysis of ARPES data using a tight-binding model found the Fermi velocity to be 1.003-1.042×106 m/s, interlayer asymmetry Δ/2 = 48-56 meV, and interlayer coupling γ1 = 0.6-0.611 eV.
3) Additional trilayer graphene was studied at room temperature using a 74eV photon energy, showing a doped sample with a 350
This document summarizes the development of a new composite sensor material made of graphite and epoxy resin. Preliminary studies tested different ratios of graphite and epoxy to find the ideal composition. The 65% graphite composite was found to have suitable properties like stability, moldability and low cost. Further characterization of the 65% composite showed it has low surface roughness and hardness, making it suitable for use as an electroanalytical sensor substrate. Cyclic voltammetry demonstrated the composite has comparable electroactive properties to glassy carbon. The new low-cost composite shows potential for use in electrochemical sensors and cells.
Three hypothetical buried massive sulphide orebodies were modeled with ZTEM to test their detectability at depths of 700m, 1400m, and 2100m. 2D forward and inversion modeling found that a 7.5Mt orebody with a conductivity of 0.1 S/m would produce a detectable ZTEM response above the noise level at all three depths. Larger 15Mt and 30Mt bodies were also expected to be detectable. However, the modeling showed the layered rock cover and individual intrusive bodies would not be resolvable, only the conductive orebodies.
This doctoral dissertation examines the use of reduced graphene oxide and its composites for various energy applications. The document outlines the synthesis of reduced graphene oxide through chemical reduction of graphene oxide. Characterization shows the reduced graphene oxide has a layered morphology. The dissertation discusses using reduced graphene oxide composites with materials like ZnO, Ag, and Ag2O as electron transport layers to improve dye-sensitized solar cell performance. Reduced graphene oxide is also investigated as a counter electrode material for dye-sensitized solar cells. Additionally, the potential of reduced graphene oxide composites with polymers and metal oxides for supercapacitors, lithium-ion batteries, and electromagnetic interference shielding is reviewed. Specific applications demonstrated include a reduced graphene oxide
- Atomic force microscopy (AFM) uses a sharp tip to scan over a sample surface and measure forces between the tip and sample. Gerd Binning invented the AFM in 1986.
- There are three main imaging modes: contact mode, tapping mode, and non-contact mode. Non-contact mode operates with the tip oscillating above the surface without touching.
- Advantages of non-contact AFM include that it exerts low forces and avoids damaging soft samples or contaminating the tip. Disadvantages include lower resolution and slower scanning speeds. Applications include analyzing surface roughness, thin film growth, and material properties like stiffness.
1) The document summarizes research into synthesizing and processing Mn0.4Fe0.3Ga0.3 nanoparticles for potential use in permanent magnets.
2) Through techniques like arc melting, melt spinning, and heat/mechanical treatments, the researchers were able to alter the structure and improve the magnetic properties.
3) Their analysis found that the nanoparticles crystallized in the desirable L12 cubic structure and that the magnetic properties depended on factors like annealing temperature and milling time.
Microscopy microanalysis microstructures_the european physical journal_applie...Andrea Sentimenti
This document describes a method for fabricating nano-sized carbon tips in a scanning electron microscope (SEM) using controlled carbon contamination. Key steps include: using a 30kV beam for highest contamination rate; smallest spot size (~5nm); stable, well-focused beam; and a carbon block nearby to increase carbon concentration. Tips with 10° aperture and ~5nm tip are produced in under 60 seconds. Successive focusing during growth produces tips shaped like stacked cones rather than a single paraboloid. The tips are used as probes in atomic force microscopy, achieving higher resolution than conventional probes due to their small size and shape. They are also used as field emitters for electron guns due to their nanoscale size and
The document discusses the concept of using laser trapped mirrors (LTM) in space. LTMs would involve using laser light to trap microscopic particles in patterns that act as reflective surfaces, allowing for the creation of very large, lightweight mirrors. The goals of the project discussed are to demonstrate a small LTM in water, model LTMs computationally including optical binding forces, and estimate mirror stability, quality and laser power needs for a vacuum environment. LTMs could enable very large aperture mirrors weighing only 100g that are resilient to damage and can self-heal.
This document discusses neutron radiography techniques and applications. It describes the principles of neutron radiography and reviews techniques such as the direct exposure technique using gadolinium converter foil, the transfer technique using indium or dysprosium foil, and the track-etch technique using nitrocellulose film. The document also reviews applications of neutron radiography in fields such as the nuclear industry, other industrial uses, and non-industrial areas like biology and medicine.
Magnetic,Optical And Thermal Studies of Ppy/Bafetio NanocompositeIJERDJOURNAL
ABSTRACT: This paper presents investigations on magnetic,optical and thermal properties of Ti doped barium ferrite substituted PPY nanocomposite prepared by impregnation technique
This document summarizes Konrad Dziatkowski's research on magnetic anisotropy in dilute magnetic semiconductors, specifically (III,Mn)V materials. It provides an overview of ferromagnetism in (Ga,Mn)As and challenges in growing high-quality films. It also describes experiments using ferromagnetic resonance to characterize magnetic anisotropy, including polar, azimuthal, and reorientation effects. Exchange biasing of (Ga,Mn)As with MnO is shown to induce unidirectional anisotropy. The goal is to understand magnetic interactions and anisotropy in these materials for applications in spin-based electronics.
The document describes an experiment that used in situ x-ray diffraction to observe the formation of platinum silicide (PtSi) phases when annealing a platinum thin film deposited on silicon. Key findings include:
- PtSi phase formation began around 225°C and halted at 300°C during vacuum annealing, while annealing in air resulted in incomplete reaction due to an amorphous silicon dioxide layer forming.
- The only silicide phases that persisted during heat treatments were PtSi(101) and PtSi(002).
- Thermal expansion measurements found the platinum thin film's coefficient of linear expansion was 1.01 × 10−5 C−1, close to the bulk value of 9 ×
Atomic Plane Resolution Electron Magnetic Circular DichroismRiccardo Di Stefano
The document provides an overview of magnetic measurements using atomic-plane resolution electron magnetic circular dichroism (APR-EMCD). APR-EMCD allows for magnetic measurements with atomic resolution by using a convergent atomic-sized electron probe in a three-beam condition. In a single acquisition, APR-EMCD can obtain an annular dark field image, thickness information, and left and right circularly polarized EELS spectra to measure the EMCD effect without needing to modify conventional STEM microscopes. Experiments on 30nm thin Fe samples demonstrated the localization of the APR-EMCD signal at positions ±d/4 from lattice planes in agreement with simulations. Data analysis using canonical polyadic decomposition helped identify the magnetic
Plenary lecture of the XIII SBPMat (Brazilian MRS) meeting, given on September 30th, 2014, in João Pessoa (Brazil) by Sir Colin Humphreys, Professor at University of Cambridge (U.K.).
Atomic force microscopy (AFM) is a technique used to image surfaces at the nanoscale. The document outlines the history, components, operating modes, applications, and limitations of AFM. It discusses how AFM works by scanning a sample with a sharp tip attached to a flexible cantilever, measuring deflections to construct 3D surface images. Three common modes are contact, non-contact, and tapping mode. AFM can image a variety of materials and is useful for measuring surface roughness, adhesion, and other nanoscale properties. While resolution is limited by tip size, continued improvements aim to develop sharper tips and less damaging probes.
Rajeev R. Pillai fabricated lithographically patterned cobalt microstructures and characterized their properties. He used DC magnetron sputtering to deposit a thin film of cobalt on a silicon substrate, then direct laser beam writing and ion beam etching to pattern the cobalt film. Atomic force microscopy and magnetic resistance measurements were used to characterize the structural and magnetic properties of the cobalt microstructures. The resistance was found to vary with the angle between the magnetic field and current, showing the anisotropic magnetoresistance effect.
1) O documento descreve pesquisas sobre diamante produzido por deposição química em fase vapor (Diamante-CVD) e materiais relacionados ao carbono conduzidas no INPE e na indústria.
2) As pesquisas incluem projetos sobre diamante-CVD, nanoestruturas de carbono e carbono amorfo como diamante (DLC), com foco em aplicações espaciais e comerciais destes materiais.
3) Resultados principais incluem o desenvolvimento de ferramentas médicas e de perfuração
O documento discute inovação como fonte de resultados para empresas e identifica meios para avaliar e propor ações para buscar esses resultados. Ele aborda dimensões da inovação como tecnologia, mercado e organização e apresenta resultados possíveis com inovação em modelos fechados e abertos. O texto também descreve benchmarks, diagnósticos, planos de ação e ações para políticas públicas, processos, estrutura organizacional e competências relacionadas à inovação.
The document reports on an ARPES microscopy study of free-standing bilayer graphene. Key findings include:
1) Bilayer graphene samples were prepared by mechanical exfoliation on 5μm wells and studied using ARPES microscopy between 110-300K.
2) Analysis of ARPES data using a tight-binding model found the Fermi velocity to be 1.003-1.042×106 m/s, interlayer asymmetry Δ/2 = 48-56 meV, and interlayer coupling γ1 = 0.6-0.611 eV.
3) Additional trilayer graphene was studied at room temperature using a 74eV photon energy, showing a doped sample with a 350
This document summarizes the development of a new composite sensor material made of graphite and epoxy resin. Preliminary studies tested different ratios of graphite and epoxy to find the ideal composition. The 65% graphite composite was found to have suitable properties like stability, moldability and low cost. Further characterization of the 65% composite showed it has low surface roughness and hardness, making it suitable for use as an electroanalytical sensor substrate. Cyclic voltammetry demonstrated the composite has comparable electroactive properties to glassy carbon. The new low-cost composite shows potential for use in electrochemical sensors and cells.
Three hypothetical buried massive sulphide orebodies were modeled with ZTEM to test their detectability at depths of 700m, 1400m, and 2100m. 2D forward and inversion modeling found that a 7.5Mt orebody with a conductivity of 0.1 S/m would produce a detectable ZTEM response above the noise level at all three depths. Larger 15Mt and 30Mt bodies were also expected to be detectable. However, the modeling showed the layered rock cover and individual intrusive bodies would not be resolvable, only the conductive orebodies.
This doctoral dissertation examines the use of reduced graphene oxide and its composites for various energy applications. The document outlines the synthesis of reduced graphene oxide through chemical reduction of graphene oxide. Characterization shows the reduced graphene oxide has a layered morphology. The dissertation discusses using reduced graphene oxide composites with materials like ZnO, Ag, and Ag2O as electron transport layers to improve dye-sensitized solar cell performance. Reduced graphene oxide is also investigated as a counter electrode material for dye-sensitized solar cells. Additionally, the potential of reduced graphene oxide composites with polymers and metal oxides for supercapacitors, lithium-ion batteries, and electromagnetic interference shielding is reviewed. Specific applications demonstrated include a reduced graphene oxide
- Atomic force microscopy (AFM) uses a sharp tip to scan over a sample surface and measure forces between the tip and sample. Gerd Binning invented the AFM in 1986.
- There are three main imaging modes: contact mode, tapping mode, and non-contact mode. Non-contact mode operates with the tip oscillating above the surface without touching.
- Advantages of non-contact AFM include that it exerts low forces and avoids damaging soft samples or contaminating the tip. Disadvantages include lower resolution and slower scanning speeds. Applications include analyzing surface roughness, thin film growth, and material properties like stiffness.
1) The document summarizes research into synthesizing and processing Mn0.4Fe0.3Ga0.3 nanoparticles for potential use in permanent magnets.
2) Through techniques like arc melting, melt spinning, and heat/mechanical treatments, the researchers were able to alter the structure and improve the magnetic properties.
3) Their analysis found that the nanoparticles crystallized in the desirable L12 cubic structure and that the magnetic properties depended on factors like annealing temperature and milling time.
Microscopy microanalysis microstructures_the european physical journal_applie...Andrea Sentimenti
This document describes a method for fabricating nano-sized carbon tips in a scanning electron microscope (SEM) using controlled carbon contamination. Key steps include: using a 30kV beam for highest contamination rate; smallest spot size (~5nm); stable, well-focused beam; and a carbon block nearby to increase carbon concentration. Tips with 10° aperture and ~5nm tip are produced in under 60 seconds. Successive focusing during growth produces tips shaped like stacked cones rather than a single paraboloid. The tips are used as probes in atomic force microscopy, achieving higher resolution than conventional probes due to their small size and shape. They are also used as field emitters for electron guns due to their nanoscale size and
The document discusses the concept of using laser trapped mirrors (LTM) in space. LTMs would involve using laser light to trap microscopic particles in patterns that act as reflective surfaces, allowing for the creation of very large, lightweight mirrors. The goals of the project discussed are to demonstrate a small LTM in water, model LTMs computationally including optical binding forces, and estimate mirror stability, quality and laser power needs for a vacuum environment. LTMs could enable very large aperture mirrors weighing only 100g that are resilient to damage and can self-heal.
This document discusses neutron radiography techniques and applications. It describes the principles of neutron radiography and reviews techniques such as the direct exposure technique using gadolinium converter foil, the transfer technique using indium or dysprosium foil, and the track-etch technique using nitrocellulose film. The document also reviews applications of neutron radiography in fields such as the nuclear industry, other industrial uses, and non-industrial areas like biology and medicine.
Magnetic,Optical And Thermal Studies of Ppy/Bafetio NanocompositeIJERDJOURNAL
ABSTRACT: This paper presents investigations on magnetic,optical and thermal properties of Ti doped barium ferrite substituted PPY nanocomposite prepared by impregnation technique
This document summarizes Konrad Dziatkowski's research on magnetic anisotropy in dilute magnetic semiconductors, specifically (III,Mn)V materials. It provides an overview of ferromagnetism in (Ga,Mn)As and challenges in growing high-quality films. It also describes experiments using ferromagnetic resonance to characterize magnetic anisotropy, including polar, azimuthal, and reorientation effects. Exchange biasing of (Ga,Mn)As with MnO is shown to induce unidirectional anisotropy. The goal is to understand magnetic interactions and anisotropy in these materials for applications in spin-based electronics.
The document describes an experiment that used in situ x-ray diffraction to observe the formation of platinum silicide (PtSi) phases when annealing a platinum thin film deposited on silicon. Key findings include:
- PtSi phase formation began around 225°C and halted at 300°C during vacuum annealing, while annealing in air resulted in incomplete reaction due to an amorphous silicon dioxide layer forming.
- The only silicide phases that persisted during heat treatments were PtSi(101) and PtSi(002).
- Thermal expansion measurements found the platinum thin film's coefficient of linear expansion was 1.01 × 10−5 C−1, close to the bulk value of 9 ×
Atomic Plane Resolution Electron Magnetic Circular DichroismRiccardo Di Stefano
The document provides an overview of magnetic measurements using atomic-plane resolution electron magnetic circular dichroism (APR-EMCD). APR-EMCD allows for magnetic measurements with atomic resolution by using a convergent atomic-sized electron probe in a three-beam condition. In a single acquisition, APR-EMCD can obtain an annular dark field image, thickness information, and left and right circularly polarized EELS spectra to measure the EMCD effect without needing to modify conventional STEM microscopes. Experiments on 30nm thin Fe samples demonstrated the localization of the APR-EMCD signal at positions ±d/4 from lattice planes in agreement with simulations. Data analysis using canonical polyadic decomposition helped identify the magnetic
Plenary lecture of the XIII SBPMat (Brazilian MRS) meeting, given on September 30th, 2014, in João Pessoa (Brazil) by Sir Colin Humphreys, Professor at University of Cambridge (U.K.).
Atomic force microscopy (AFM) is a technique used to image surfaces at the nanoscale. The document outlines the history, components, operating modes, applications, and limitations of AFM. It discusses how AFM works by scanning a sample with a sharp tip attached to a flexible cantilever, measuring deflections to construct 3D surface images. Three common modes are contact, non-contact, and tapping mode. AFM can image a variety of materials and is useful for measuring surface roughness, adhesion, and other nanoscale properties. While resolution is limited by tip size, continued improvements aim to develop sharper tips and less damaging probes.
Rajeev R. Pillai fabricated lithographically patterned cobalt microstructures and characterized their properties. He used DC magnetron sputtering to deposit a thin film of cobalt on a silicon substrate, then direct laser beam writing and ion beam etching to pattern the cobalt film. Atomic force microscopy and magnetic resistance measurements were used to characterize the structural and magnetic properties of the cobalt microstructures. The resistance was found to vary with the angle between the magnetic field and current, showing the anisotropic magnetoresistance effect.
1) O documento descreve pesquisas sobre diamante produzido por deposição química em fase vapor (Diamante-CVD) e materiais relacionados ao carbono conduzidas no INPE e na indústria.
2) As pesquisas incluem projetos sobre diamante-CVD, nanoestruturas de carbono e carbono amorfo como diamante (DLC), com foco em aplicações espaciais e comerciais destes materiais.
3) Resultados principais incluem o desenvolvimento de ferramentas médicas e de perfuração
O documento discute inovação como fonte de resultados para empresas e identifica meios para avaliar e propor ações para buscar esses resultados. Ele aborda dimensões da inovação como tecnologia, mercado e organização e apresenta resultados possíveis com inovação em modelos fechados e abertos. O texto também descreve benchmarks, diagnósticos, planos de ação e ações para políticas públicas, processos, estrutura organizacional e competências relacionadas à inovação.
Photoinduced force microscopy (PiFM) is an atomic force microscopy technique that measures photoinduced forces between a sharp tip and a sample with sub-10 nm spatial resolution. PiFM signals carry information on the sample's optical polarizability, allowing spectroscopic properties to be probed at the nanoscale. The technique works by focusing laser light near the tip-sample junction and measuring the gradient and scattering forces that arise from interactions between the optically driven tip dipole and optically induced polarization in the sample. PiFM provides both nanoscale spatial resolution and chemical sensitivity, enabling applications such as chemical imaging, linear spectroscopy, and probing nonlinear optical properties at the nanoscale.
1) O documento discute o fenômeno de cavitação em bombas, que ocorre quando a pressão de entrada cai abaixo da pressão de vapor do líquido, levando à ebulição.
2) Vários cuidados podem ser tomados para evitar a cavitação, como instalar a bomba o mais perto possível do nível da água e usar tubulações curtas.
3) O NPSH disponível e requerido são medidas para verificar se há risco de cavitação, sendo necessário que o disponível seja maior que o requerido.
Versão do seminário apresentado por Celia Olivero (Horiba) na seção UCS do Instituto Nacional de Engenharia de Superfícies no dia 28 de junho para um público de 18 estudantes, professores e profissionais de empresas.
O documento discute vários métodos para a reciclagem de elastômeros, incluindo regeneração física através de moagem, regeneração química utilizando compostos orgânicos e inorgânicos, e desenvolvimentos recentes como a dessulfuração microbiológica e o uso de materiais de fontes renováveis. O documento também discute aplicações para o pó de borracha regenerado, como a incorporação em asfalto.
This document provides definitions and concepts related to motion and forces, including:
- The three laws of Newton, definitions of force, net force, and inertia.
- The relationship between force, mass, and acceleration as expressed in the formula a=F/m.
- Different types of forces like friction and their definitions.
- The difference between mass and weight and their relationship as defined by formulas.
- Additional concepts like gravity, free fall, and terminal velocity.
- Examples and exercises are provided to help explain and apply the concepts.
The document discusses nitrogen blanket systems. It explains that a nitrogen blanket maintains a pressure of 30-50 mm H2O over atmospheric pressure to prevent oxygen from entering storage tanks. It also lists three key points about nitrogen blankets: 1) they are used when the Lower Explosive Limit is below 30%; 2) the nitrogen blanket should maintain at least 20% of the LEL or 5% of the LEL; and 3) incorrect nitrogen blanket pressures could lead to the tanks exploding.
1) O documento discute a cavitação e sua relação com a resistência de metais e ligas. A estrutura cristalina, fases presentes, e propriedades mecânicas das fases afetam a resistência à cavitação. Ligas que contêm carbonetos como segunda fase geralmente apresentam melhor desempenho, com a fração volumétrica e morfologia dos carbonetos sendo fatores importantes.
O vidro é um material antigo que pode ser reciclado infinitamente sem perder qualidade. No Brasil, 42% das embalagens de vidro são recicladas anualmente, totalizando 378 mil toneladas. A reciclagem do vidro reduz o gasto energético na produção e permite que o material seja reutilizado na fabricação de novas embalagens.
This document contains 15 multiple choice questions about forces for a "Who Wants To Be A Millionaire?" style quiz. The questions cover topics like the different types of forces, units of measurement for forces, gravity, friction, magnetic forces, and how forces affect objects. Correct answers are provided for each question.
O documento descreve as etapas de reciclagem de pavimento com adição de cimento para a rodovia SC-303 entre as cidades de Joaçaba, Lacerdópolis e Capinzal. Inclui a coleta de amostras, definição do traço da base reciclada, execução da reciclagem, tratamento superficial e aplicação de camadas de CAUQ e CAP com borracha.
A cavitação ocorre quando a pressão de um líquido é reduzida a ponto de formar bolhas de vapor, que ao se condensarem liberam energia que danifica equipamentos como bombas e turbinas hidráulicas. Isso pode ser evitado projetando a pressão de entrada do fluido para ser maior que sua pressão de vapor. A cavitação causa destruição cara de equipamentos e pode interromper o fornecimento de energia em usinas hidrelétricas.
This document summarizes research on electrostatic complexes in polymer materials science. It discusses using non-covalent interactions like π-stacking, coordination via metals, and hydrogen bonding to build supermolecular structures from polymer assemblies. It also describes techniques like layer-by-layer assembly and complex coacervation to encapsulate and pattern materials. The research aims to better understand parameters affecting polyelectrolyte brush structures and interactions through experiments using surface force apparatus.
1) A reciclagem da borracha vulcanizada é importante devido à grande quantidade de resíduos gerados anualmente.
2) Existem vários métodos de reciclagem como reutilização em outros produtos, geração de energia e produção de pó de borracha.
3) No entanto, ainda há dificuldades em se desenvolver processos industriais para a devulcanização da borracha, permitindo sua reutilização como matéria-prima.
O documento fornece uma definição e classificação detalhada dos materiais cerâmicos. Apresenta seis principais categorias de cerâmicas: 1) Cerâmica Vermelha, 2) Materiais de Revestimento, 3) Cerâmica Branca, 4) Materiais Refratários, 5) Isolantes Térmicos, 6) Fritas e Corantes. Também discute processos de fabricação, propriedades, aplicações e normas técnicas relacionadas a blocos cerâmicos usados na construção civil.
O documento discute materiais cerâmicos, incluindo suas características como bons isolantes térmicos e químicos com alta dureza. Detalha etapas na produção de peças cerâmicas como prensagem e extrusão. Também lista aplicações tradicionais, avançadas, aeroespaciais e militares de cerâmicas.
Friction. Do you know what is friction and how it plays different roles in our general life. There are many section in our life where friction is necessary like - in playing sitar and guitar, walking on the road and to hold something in our hand or in any mechanical devices. But there are many field where friction is not required like - in machines where two surfaces meet at a point. Due to this the life of the machine parts get decreased and failure may be occur there. Know more about different laws of friction, types of friction, elimination of the friction.
The document discusses temperature measurement and different temperature scales. It defines temperature and describes how thermometers are used to measure temperature. It explains the Celsius, Fahrenheit and Kelvin temperature scales, including their lower and upper fixed points which define freezing and boiling temperatures. Formulas are provided for converting between the different scales.
Dr. Mitat A. Birkan presents an overview of his program, Space Propulsion and Power, at the AFOSR 2013 Spring Review. At this review, Program Officers from AFOSR Technical Divisions will present briefings that highlight basic research programs beneficial to the Air Force.
This study investigated the impact of a nickel interlayer on the electrical resistance of a tin-tin interface under fretting loading conditions. Two coating systems were tested: bronze-tin and bronze-nickel-tin. Using variable displacement amplitude testing, the transition amplitude from partial slip to gross slip was determined. Constant displacement amplitude tests then evaluated the influence of the nickel interlayer on electrical endurance. The results showed that the nickel interlayer did not influence endurance in gross slip but eliminated copper diffusion through the tin coating, preventing copper oxide formation and extending the domain of partial slip. This increased the reliability of the electrical contact.
General accounts of Topological Insulators have been presented. A holistic idea of the basic theories related to topological insulators and material properties were presented. Furthermore, there were discussions on the 2D-Two dimensional and 3D-three dimensional topological insulators. The Dirac fermion material science and subsequent quantum oscillations were discussed in this paper.
In situ hydrodynamic spectroscopy was used to characterize porous energy storage electrodes during lithium ion insertion/extraction. The technique uses electrochemical quartz crystal microbalance (EQCM) which monitors changes in resonance frequency and width during the electrochemical process. Three experiments were conducted:
1) Validation of the technique by measuring model surfaces with known properties.
2) Characterization of spray-pyrolyzed LiMn2O4 coatings of different mass loadings, allowing determination of specific capacity.
3) In situ measurements during charging/discharging of a LiMn2O4 electrode, showing swelling and shrinking of the porous layer associated with solvent insertion and extraction. The technique provides detailed information on changes
This document summarizes molecular dynamics simulations of radiation damage in zirconia (ZrO2) at energies ranging from 0.1-0.5 MeV. The simulations find that while zirconia is highly resistant to amorphization, there is still a large number of point defects and small defect clusters created by the radiation. However, these defects are isolated from each other, resulting in dilute damage that does not disrupt the long-range crystalline structure. The simulations quantify the number of displacements and defects over time and find that electronic energy losses play an important role in the damage evolution. The findings have implications for using zirconia in nuclear waste storage by suggesting radiation can create many point defects even while
Modeling the Dependence of Power Diode on Temperature and RadiationIJPEDS-IAES
A theoretical study had been carried out on the effect of radiation on the
electrical properties of silicon power diodes. Computer program
"PDRAD2015" was developed to solve the diode equations and to
introduce the operating conditions and radiation effects upon its
parameters. Temperature increase interrupts the electrical properties of the
diode in the direction of drop voltage decrease across the p-n junction. The
model was analyzed under the influence of different radiation type (gammarays,
neutrons, protons and electrons) with various dose levels and
energies. The carrier’s diffusion lengths were seriously affected leading
to a large increase in the forward voltage. These effects were found to be
function of radiation type, fluence and energy.
This document discusses giant magnetoresistance (GMR) in magnetic multilayer systems. It begins by introducing the discovery of GMR in 1988 and describes how the resistance of these systems depends on whether the magnetic moments of adjacent ferromagnetic layers are parallel or antiparallel. The rest of the document presents a model for understanding GMR using the Boltzmann equation approach. It describes how the resistance changes when an external magnetic field switches the layers from an antiparallel to parallel configuration.
1) The document discusses a proposed method of constructing large structures in space using tailored electromagnetic force fields to arrange rubble into cylindrical walls and other shapes.
2) It summarizes progress validating the concept experimentally at small scales and outlines plans to demonstrate a full-scale prototype.
3) The concept could enable massive permanent human habitats in space by automating construction using local asteroid or lunar materials.
The document summarizes a PhD thesis on numerically and experimentally studying melt flow under the influence of electromagnetic fields. It discusses motivations for improving directional solidification of silicon for solar cells. This includes increasing crucible size and using lower purity feedstock. Electromagnetic field stirring is proposed to tailor convection and address challenges from these trends. A model experiment is developed using a GaInSn melt, and ultrasound Doppler velocimetry is used to validate numerical simulations of melt flow patterns under symmetric and asymmetric electrode configurations. The flow structures are analyzed in terms of Lorentz forces and radial pressure gradients.
This document reports on a project to measure the dielectric properties of materials at microwave frequencies. It discusses key concepts such as dielectric constant, permittivity, permeability, Maxwell's equations and how they relate to a material's ability to store and transmit electromagnetic energy. It describes measurement techniques using resonant cavities and waveguides to characterize a material's dielectric constant and loss factor. Sample preparation and ensuring uniform temperature and moisture conditions are important. Both resonant cavity and transmission line methods are covered, with cavity methods noted as providing higher accuracy for loss measurements.
A Study on Liquid Dielectric Breakdown in Micro-EDM Discharge - Cognitio paperSantosh Verma
The research work carried out in this paper, aims at
understanding the breakdown phenomenon of liquid dielectric by the low energy ultra-short pulsed electric discharge produced between tiny electrodes (~ 100µm diameter electrode) through experimental studies In literature not many studies are reported on liquid dielectric breakdown mechanism, and in micro-EDM no published literature discusses about this. Therefore, a detailed study on literature has been performed and preliminary
experiments have conducted on micro-EDM to understand the glow discharge and its breakdown phenomenon better, towards validation of scientific analogies for micro-EDM process conditions.
Coulomb drag between graphene and LaAlO3/SrTiO3 heterostructuresQingGuo5
Vertical stacking of heterostructures that combine layered materials offer new ways of combining interesting properties of dissimilar electronic materials. Over the past few years we have been integrating graphene with complex-oxide heterostructures, specifically, the LaAlO /SrTiO system. Furthermore, conducting nanostructures can be written under graphene, producing interesting interactions between the two systems. Here we report Coulomb drag measurements between single-layer graphene and a conductive LaAlO /SrTiO interface. Fabry-Perot oscillations are observed in both graphene and drag signal in graphene, which indicate the local doping in graphene by conductive atomic force microscope(c-AFM) lithography. While the drag resistance is greatly enhanced in SrTiO in the superconducting region, the drag in graphene remain unchanged. We also observed key differences between longitudinal drag and hall drag in both graphene and SrTiO .
1) The document discusses the potential of piezoelectric biopolymers for energy harvesting applications in wearable devices.
2) It specifically examines poly(L-lactic acid) (PLLA) nanofibers produced by electrospinning and how annealing affects their crystallinity, mechanical, and piezoelectric properties.
3) The research finds that annealing increases crystallinity and improves mechanical and piezoelectric properties compared to as-spun amorphous fibers. However, the piezoelectric response of PLLA fibers remains lower than poly(vinylidene fluoride-co-trifluoroethylene) thin films.
This document discusses radiation hardness assurance (RHA) for electronics used in space systems. It notes that the space radiation environment can degrade electronics over time and discusses the need for RHA activities to ensure components perform as designed after radiation exposure. Some key points made:
- RHA consists of all steps to ensure components work as intended after radiation exposure, including environment definition, part selection/testing, layout, and mitigation techniques.
- Traditional particle accelerators may not accurately simulate the natural space radiation environment. High power lasers are a promising alternative for testing due to their similar exponential energy distributions.
- The document revisits the definition of RHA and notes it goes beyond just individual components to consider things like the radiation
Long term power transmission failures in southeastern brazil and the geophysi...Carlos Bella
This document analyzes power transmission failures in southeastern Brazil over 9 years from 1998 to 2006. It finds that most failures were attributed to atmospheric discharges, with 1957 failures out of 4572 total for the 138kV grid and 170 out of 763 for the 440kV grid. There was a clear concentration of failures during the region's thunderstorm season. The study also found a significant 67% and 77% reduction in failure rates per year for the 138kV and 440kV grids respectively, corresponding to the decay in sunspot numbers over the solar cycle. No obvious correlation was found between failures and geomagnetic activity indices.
The document describes an experiment where quantum state transfer was realized between atomic and photonic qubits. Efficiencies of 0.04 and 0.03 were measured for the read and write processes respectively. It is estimated that implementing a second node and joint detection of signal photons could realize quantum repeater protocols and distant teleportation of atomic qubits at a rate of around 3 x 10-7 s-1. Improvements to efficiency through increasing optical thickness or eliminating transmission losses could increase the rate by several orders of magnitude. The results also demonstrate the possibility of multiple atomic qubits in a quantum node using multiple light beams.
Analysis of electromagnetic pollution due to high voltage transmission linesAlexander Decker
This document analyzes electromagnetic pollution from high voltage power transmission lines in Nigeria. It measures electric and magnetic field levels from 132kV and 330kV lines in Bauchi and Gombe areas. Field measurements were taken within 450m horizontally and 1.5m vertically from the lines. Measured field levels for both general public and occupational exposures were found to be within safety limits set by ICNIRP. The highest magnetic field measured was 45mG and 100mG for public and occupational exposures, respectively. The highest electric fields were 130V/m for both exposure groups. These levels represent a small percentage of ICNIRP safety limits.
This document discusses the integration of a layered ferromagnetic composite material into a microwave propagation structure to enable tunable microwave device applications. The material combines the large saturation magnetization of ferromagnetic material with the low loss of dielectrics. Electromagnetic analysis was carried out to understand how the material properties are affected by the microwave field pattern and dc magnetic fields. Experimental results demonstrated tunable band stop filter and switch devices using the material, with over 50% tunability achieved in the filter using a 250 Oe dc field.
My research at Boston University (May 2013)
1. Thesis: Viscoelastic testing and modeling of PDMS micropillars for cellular force measurement
2. Side Projects
1) Conducting polymer actuators
2) PDMS and conducting polymer nanowire composites
3) Silicon oxycarbide thin films
4) Tribological study of DLC coatings
Similar to Friction Force and its Relationship to the Electrostatic Charges at Interfaces. (20)
Apresentação do Dr. Felipe de Campos Carreri (ISIEngenharia de Superfícies) no 1° Workshop de Tecnologias a Plasma para o Setor Automotivo, realizado em Belo Horizonte (MG) em 3 de agosto de 2017, pelo ISI de Engenharia de Superfícies (participante do Instituto Nacional de Engenharia de Superfícies).
1) O documento apresenta estudos sobre tratamentos térmicos e revestimentos superficiales aplicados a aços e ligas metálicas, com o objetivo de melhorar suas propriedades mecânicas e resistência ao desgaste.
2) Foram realizados ensaios de fadiga térmica em aços para moldes de injeção de alumínio e análises das propriedades de fadiga do aço ABNT 4140 após nitretação.
3) Também são apresentadas publicações e estudos sobre nitretação a plasma, revestimentos
O documento discute as leis fundamentais que regem as forças de atrito. Apresenta a definição de atrito e explica que é a força de resistência ao movimento entre superfícies. Também discute a importância do estudo das forças de atrito para melhorar a eficiência energética e reduzir as emissões de gases do efeito estufa. Explica que as forças de atrito podem ser interpretadas em nível nano através da contribuição fonônica da dissipação de energia nas vibrações químicas das superfícies em cont
O documento discute demandas industriais, desafios e tendências para pesquisa em engenharia de superfícies. Apresenta propostas do Instituto SENAI de Inovação em Engenharia de Superfícies, incluindo planta piloto para deposição a plasma e desenvolvimento de revestimentos. Também aborda desafios como controle de processos reativos e materiais super-hidrofóbicos duráveis, e tendências como inovações em equipamentos e fontes de plasma.
Resumo de trabalho sobre o fenômeno de superlubrificação entre superfícies cerâmicas realizado no Laboratório de Fenômenos de Superfície, associado ao Instituto Nacional de Engenharia de Superfícies.
Invited lecture of the Simposium N "Surface Engineering - functional coatings and modified surfaces" at the XIII SBPMat (Brazilian MRS) meeting, in João Pessoa (Brazil). The lecture took place on September 29th, 2014.
The speaker was Prof. Amilton Sinatora (Escola Politécnica da USP, São Paulo state, Brazil).
Invited lecture of the Simposium N "Surface Engineering - functional coatings and modified surfaces" at the XIII SBPMat (Brazilian MRS) meeting, in João Pessoa (Brazil). The lecture took place on September 29th, 2014.
The speaker was Christopher Muratore, "Wright Brothers Institute Endowed Chair Professor" at the Department of Chemical and Materials Engineering from University of Dayton (USA).
Invited lecture of the Simposium N "Surface Engineering - functional coatings and modified surfaces" at the XIII SBPMat (Brazilian MRS) meeting, in João Pessoa (Brazil). The lecture took place on September 30th, 2014.
The speaker was Professor Christoph Genzel, from the Helmholtz-Zentrum Berlin für Materialien und Energie (HZB), in Germany, where he heads the Department of Microstructure and Residual Stress Analysis and he coordinates a group of diffraction and scattering. Genzel is also Associate Professor at the Technische Universität Berlin.
Workshop oferecido no dia 26 de agosto de 2014 na Universidade de Caxias do Sul (UCS) pelo professor Deniol Tanaka, professor titular da Escola Politécnica da USP (EPUSP), doutor em Engenharia Metalúrgica pela EPUSP, mestre em Ciências pelo ITA e engenheiro mecânico pela UNESP. O workshop foi realizado com a participação de cerca de 40 pessoas, entre outras, graduandos de Engenharias e Fotografia, mestrandos e doutorandos de Materiais e profissionais de empresas.
A workshop formou parte da programação do 1º Seminário de Tecnologia, Inovação e Desenvolvimento Social do Centro de Ciências Exatas e da Tecnologia (CCET) da UCS e foi patrocinado pelo Instituto Nacional de Engenharia de Superfícies.
ATENÇÃO: O arquivo original desta apresentação tem várias animações. Faça download do arquivo se deseja apreciar a apresentação com animações.
Palestra proferida pelo professor Deniol Tanaka (Escola Politécnica da USP), estudioso de Leonardo da Vinci desde a década de 1970. A apresentação ocorreu no UCS Teatro (teatro da Universidade de Caxias do Sul, UCS, no Rio Grande do Sul) na noite de 25 de agosto de 2014, com um público de cerca de 800 pessoas. Foi a palestra inaugural do 1º Seminário de Tecnologia, Inovação e Desenvolvimento Social do Centro de Ciências Exatas e da Tecnologia (CCET) da UCS e também a palestra comemorativa dos 10 anos do Programa de Pós-Graduação em Materiais (PGMAT) da UCS. A palestra foi patrocinada pelo Instituto Nacional de Engenharia de Superfícies.
ATENÇÃO: O arquivo original desta apresentação tem várias animações. Faça download do arquivo se deseja apreciar a apresentação com animações.
Seminário proferido por Iñigo Braceras Izagirre, do Centro de P,D e I TECNALIA (San Sebastián, Espanha) na seção UCS do Instituto Nacional de Engenharia de Superfícies, no dia 17 de abril para um público de cerca de 30 estudantes e professores.
- O documento discute a análise de esforços de contato em sistemas com e sem revestimento utilizando mecânica computacional.
- É apresentada a relevância da mecânica do contato e exemplos de análises numéricas como indentação instrumentada, indentação em sistemas com filme e substrato, esforços normais e tangenciais e simulações por dinâmica molecular.
- São descritas técnicas para identificar características mecânicas com precisão, associar problemas de contato a essas características
Arquivo do seminário apresentado pelo professor Fernando Alvarez, pesquisador da seção Unicamp do Instituto Nacional de Engenharia de Superfícies, no dia 20 de agosto de 2013, na seção UCS do Instituto, para um público de 30 estudantes e professores de cursos de graduação e pós-graduação.
Alexandre Martins Barros tem formação em engenharia metalúrgica e mestrado e doutorado em metalurgia física e comportamento mecânico. Trabalhou no SENAI Bahia, Ford e SENAI DN, onde atuou como diretor do Instituto SENAI de Engenharia de Superfícies.
Palestra apresentada por Carlos A. Figueroa, co-fundador da Plasmar Tecnologia (empresa spinoff da seção UCS do Instituto Nacional de Engenharia de Superfícies), na Câmara de Indústria, Comércio e Serviços de Caxias do Sul em 24 de agosto de 2012 para cerca de 200 pessoas e na Universidade de Caxias do Sul, no dia 1° de novembro, para cerca de 20 professores e estudantes.
Este livro eletrônico reúne 17 artigos de divulgação escritos por pesquisadores do Instituto Nacional de Engenharia de Superfícies sobre processos, materiais, aplicações e métodos da engenharia de superfícies. Faça download aqui ou entre em contato para solicitar o PDF: http://engenhariadesuperficies.com.br/fale-conosco.asp.
Apresentado pelo professor Israel Baumvol para lideranças dos sindicatos parceiros da seção UCS do Instituto, na CIC-Caxias do Sul no dia 27 de junho de 2012.
Apresentado pelo professor Thierry Czerwiec (Institut Jean Lamour, Nancy, France) no dia 12 de junho na Universidade de Caxias do Sul, em seminário realizado pelo Instituto Nacional de Engenharia de Superfícies e o PGMAT da UCS para um público de 16 estudantes e professores.
O documento descreve as atividades de divulgação, difusão e transferência de conhecimento sobre engenharia de superfícies realizadas pelo INCT de Engenharia de Superfícies para a sociedade. O plano de divulgação inclui disponibilizar conteúdo online, realizar palestras, publicar artigos e ter presença em mídias sociais para ampliar o alcance. Vários resultados foram obtidos, como mais de 700 participantes em eventos e mais de 130 mil visualizações online. Um caso de sucesso resultou em um projet
Palestra apresentada pelo prof. Carlos A. Figueroa (seção UCS do Instituto Nacional de Engenharia de Superfícies) para cerca de 25 supervisores e gerentes de diversas unidades do grupo Randon, no dia 22 de março de 2012, nas instalações da Randon (Caxias do Sul).
More from Instituto Nacional de Engenharia de Superfícies (20)
Unlocking the mysteries of reproduction: Exploring fecundity and gonadosomati...AbdullaAlAsif1
The pygmy halfbeak Dermogenys colletei, is known for its viviparous nature, this presents an intriguing case of relatively low fecundity, raising questions about potential compensatory reproductive strategies employed by this species. Our study delves into the examination of fecundity and the Gonadosomatic Index (GSI) in the Pygmy Halfbeak, D. colletei (Meisner, 2001), an intriguing viviparous fish indigenous to Sarawak, Borneo. We hypothesize that the Pygmy halfbeak, D. colletei, may exhibit unique reproductive adaptations to offset its low fecundity, thus enhancing its survival and fitness. To address this, we conducted a comprehensive study utilizing 28 mature female specimens of D. colletei, carefully measuring fecundity and GSI to shed light on the reproductive adaptations of this species. Our findings reveal that D. colletei indeed exhibits low fecundity, with a mean of 16.76 ± 2.01, and a mean GSI of 12.83 ± 1.27, providing crucial insights into the reproductive mechanisms at play in this species. These results underscore the existence of unique reproductive strategies in D. colletei, enabling its adaptation and persistence in Borneo's diverse aquatic ecosystems, and call for further ecological research to elucidate these mechanisms. This study lends to a better understanding of viviparous fish in Borneo and contributes to the broader field of aquatic ecology, enhancing our knowledge of species adaptations to unique ecological challenges.
The binding of cosmological structures by massless topological defectsSérgio Sacani
Assuming spherical symmetry and weak field, it is shown that if one solves the Poisson equation or the Einstein field
equations sourced by a topological defect, i.e. a singularity of a very specific form, the result is a localized gravitational
field capable of driving flat rotation (i.e. Keplerian circular orbits at a constant speed for all radii) of test masses on a thin
spherical shell without any underlying mass. Moreover, a large-scale structure which exploits this solution by assembling
concentrically a number of such topological defects can establish a flat stellar or galactic rotation curve, and can also deflect
light in the same manner as an equipotential (isothermal) sphere. Thus, the need for dark matter or modified gravity theory is
mitigated, at least in part.
The technology uses reclaimed CO₂ as the dyeing medium in a closed loop process. When pressurized, CO₂ becomes supercritical (SC-CO₂). In this state CO₂ has a very high solvent power, allowing the dye to dissolve easily.
hematic appreciation test is a psychological assessment tool used to measure an individual's appreciation and understanding of specific themes or topics. This test helps to evaluate an individual's ability to connect different ideas and concepts within a given theme, as well as their overall comprehension and interpretation skills. The results of the test can provide valuable insights into an individual's cognitive abilities, creativity, and critical thinking skills
Authoring a personal GPT for your research and practice: How we created the Q...Leonel Morgado
Thematic analysis in qualitative research is a time-consuming and systematic task, typically done using teams. Team members must ground their activities on common understandings of the major concepts underlying the thematic analysis, and define criteria for its development. However, conceptual misunderstandings, equivocations, and lack of adherence to criteria are challenges to the quality and speed of this process. Given the distributed and uncertain nature of this process, we wondered if the tasks in thematic analysis could be supported by readily available artificial intelligence chatbots. Our early efforts point to potential benefits: not just saving time in the coding process but better adherence to criteria and grounding, by increasing triangulation between humans and artificial intelligence. This tutorial will provide a description and demonstration of the process we followed, as two academic researchers, to develop a custom ChatGPT to assist with qualitative coding in the thematic data analysis process of immersive learning accounts in a survey of the academic literature: QUAL-E Immersive Learning Thematic Analysis Helper. In the hands-on time, participants will try out QUAL-E and develop their ideas for their own qualitative coding ChatGPT. Participants that have the paid ChatGPT Plus subscription can create a draft of their assistants. The organizers will provide course materials and slide deck that participants will be able to utilize to continue development of their custom GPT. The paid subscription to ChatGPT Plus is not required to participate in this workshop, just for trying out personal GPTs during it.
When I was asked to give a companion lecture in support of ‘The Philosophy of Science’ (https://shorturl.at/4pUXz) I decided not to walk through the detail of the many methodologies in order of use. Instead, I chose to employ a long standing, and ongoing, scientific development as an exemplar. And so, I chose the ever evolving story of Thermodynamics as a scientific investigation at its best.
Conducted over a period of >200 years, Thermodynamics R&D, and application, benefitted from the highest levels of professionalism, collaboration, and technical thoroughness. New layers of application, methodology, and practice were made possible by the progressive advance of technology. In turn, this has seen measurement and modelling accuracy continually improved at a micro and macro level.
Perhaps most importantly, Thermodynamics rapidly became a primary tool in the advance of applied science/engineering/technology, spanning micro-tech, to aerospace and cosmology. I can think of no better a story to illustrate the breadth of scientific methodologies and applications at their best.
Travis Hills' Endeavors in Minnesota: Fostering Environmental and Economic Pr...Travis Hills MN
Travis Hills of Minnesota developed a method to convert waste into high-value dry fertilizer, significantly enriching soil quality. By providing farmers with a valuable resource derived from waste, Travis Hills helps enhance farm profitability while promoting environmental stewardship. Travis Hills' sustainable practices lead to cost savings and increased revenue for farmers by improving resource efficiency and reducing waste.
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
The use of Nauplii and metanauplii artemia in aquaculture (brine shrimp).pptxMAGOTI ERNEST
Although Artemia has been known to man for centuries, its use as a food for the culture of larval organisms apparently began only in the 1930s, when several investigators found that it made an excellent food for newly hatched fish larvae (Litvinenko et al., 2023). As aquaculture developed in the 1960s and ‘70s, the use of Artemia also became more widespread, due both to its convenience and to its nutritional value for larval organisms (Arenas-Pardo et al., 2024). The fact that Artemia dormant cysts can be stored for long periods in cans, and then used as an off-the-shelf food requiring only 24 h of incubation makes them the most convenient, least labor-intensive, live food available for aquaculture (Sorgeloos & Roubach, 2021). The nutritional value of Artemia, especially for marine organisms, is not constant, but varies both geographically and temporally. During the last decade, however, both the causes of Artemia nutritional variability and methods to improve poorquality Artemia have been identified (Loufi et al., 2024).
Brine shrimp (Artemia spp.) are used in marine aquaculture worldwide. Annually, more than 2,000 metric tons of dry cysts are used for cultivation of fish, crustacean, and shellfish larva. Brine shrimp are important to aquaculture because newly hatched brine shrimp nauplii (larvae) provide a food source for many fish fry (Mozanzadeh et al., 2021). Culture and harvesting of brine shrimp eggs represents another aspect of the aquaculture industry. Nauplii and metanauplii of Artemia, commonly known as brine shrimp, play a crucial role in aquaculture due to their nutritional value and suitability as live feed for many aquatic species, particularly in larval stages (Sorgeloos & Roubach, 2021).
The debris of the ‘last major merger’ is dynamically youngSérgio Sacani
The Milky Way’s (MW) inner stellar halo contains an [Fe/H]-rich component with highly eccentric orbits, often referred to as the
‘last major merger.’ Hypotheses for the origin of this component include Gaia-Sausage/Enceladus (GSE), where the progenitor
collided with the MW proto-disc 8–11 Gyr ago, and the Virgo Radial Merger (VRM), where the progenitor collided with the
MW disc within the last 3 Gyr. These two scenarios make different predictions about observable structure in local phase space,
because the morphology of debris depends on how long it has had to phase mix. The recently identified phase-space folds in Gaia
DR3 have positive caustic velocities, making them fundamentally different than the phase-mixed chevrons found in simulations
at late times. Roughly 20 per cent of the stars in the prograde local stellar halo are associated with the observed caustics. Based
on a simple phase-mixing model, the observed number of caustics are consistent with a merger that occurred 1–2 Gyr ago.
We also compare the observed phase-space distribution to FIRE-2 Latte simulations of GSE-like mergers, using a quantitative
measurement of phase mixing (2D causticality). The observed local phase-space distribution best matches the simulated data
1–2 Gyr after collision, and certainly not later than 3 Gyr. This is further evidence that the progenitor of the ‘last major merger’
did not collide with the MW proto-disc at early times, as is thought for the GSE, but instead collided with the MW disc within
the last few Gyr, consistent with the body of work surrounding the VRM.
The debris of the ‘last major merger’ is dynamically young
Friction Force and its Relationship to the Electrostatic Charges at Interfaces.
1. Friction Force and its Relationship to the
Electrostatic Charges at Interfaces
Dr. Thiago A L Burgo
2. Outline
Unicamp
• Friction coefficient induced
by electrostatic charges
– Coefficient of rolling
resistance x Electrostatic
potential (EP)
– Friction angle x EP
– Friction at nanoscale
• Lateral Force Microscopy
(LFM)
Argonne
Na/onal
Laboratory
• Tribocurrent and
macroscopic friction force
– Dependence on the
atmosphere
– Friction force fluctuations
– Electrostatic adhesion
• Nanomechanical Mapping on
tested PTFE
– Triboemission
• Concluding Remarks
• Electrostatic Discharge (ESD) and Technological Challenges
3. Explosions triggered by electrostatic discharge
https://www.youtube.com/watch?
v=6lKUsUycBNA&spfreload=10
www.firesciencetools .com
4. In October 2013, a fire of
great proportions hit
Copersucar facilities.
5. • For nanotechnology
– Electrostatic force is even
larger than the inertial
force, for micromachine
parts made of insulators.
– The electrification of the
insulator is not well
understood, especially at
the micro-scale.
• Safety and technologies
– Dust explosions
– Fires
– Pharmaceuticals
– Polymer recycling
– Electrospinning
– Solid paint
– Electrocopying
– Toner
Consequences
6. Challenges
Faced
By
Solar
Energy
Use
Calle et al. Active dust control and mitigation technology for lunar and Martian exploration. Acta
Astronautica 69, 1082-1088 (2011).
8. Surfaces
under
rela<ve
mo<on:
Triboplasma
Heinicke G.
Tribochemistry.
(1984)
Matta et al. J.
Phys. D: Appl.
Phys. (2009)
Camara, et al.
Nature (2008)
Burgo, et al.
Polym. Degrad.
Stabil. (2014)
enerated. All these
na follow a certain
plained by Suh [3].
city, normal load,
nt of hydrocarbons
,5], are correlated
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emission of both
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noemission is an
g from mechanical
Fig. 1. General scheme of triboemission [7].
K. Kajdas / Tribology International 38 (2005) 337–353
9. How
powerful
is
the
triboplasma?
!
Camara et al. Correlation between nanosecond X-ray
flashes and stick–slip friction in peeling tape. Nature,
455, 1089-1093 (2008).
X-Rays!
X-ray Fluorescence
(XRF) technology
Tribogenics
10. What
creates
sta/c
electricity?
Williams, M.W. What creates static electricity? American Scientist 100, 316-326 (2012)
• Complex and unexpected charge distribution in
every material scanned by Kelvin electrodes
(EFM, KFM/SEPM, Macro-Kelvin):
– Cardoso et al., Langmuir 1998, 1999
– Galembeck et al., Polymer 2001
– Gouveia et al., J. Phys. Chem B, 2005, 2008
– Soares et al., J. Braz. Chem. Soc. 2008
– Gouveia et al., J. Am. Chem. Soc. 2009
– Ducati et al., Langmuir 2010
– Bernardes et al., J. Phys. Chem. C 2010
– Burgo et al., J. Electrostatics 2011
11. Polymer
Ethanol
2
hours
Clean
Polymer
drying
Electrical
poten<al
scanning
with
Kelvin
electrode
OR
EXPERIMENTAL
Balance
Polymer
P:
1,5
kPa
RPM:
5000
Time:
3
s
PE
foam
Shaking
table
Polymer
Glass
spheres
or
pellets
de
PTFE
Amount:
4
g
Time:
60
min
1-‐
Cleaning
2-‐
Charging
3-‐
Charge
mapping
X
Y
Polymer
13. Formation free-radicals is followed by electron transfer:
from the hydrocarbon free-radicals to the more
electronegative fluorocarbon radicals. Ions are segregated
due to the chain size, following Flory−Huggins theory
and superseding weak electrostatic interactions between
highly spaced charges.
!
Burgo et al. Triboelectricity: macroscopic charge patterns formed by self-arraying ions on polymer
surfaces, Langmuir, 28(19), 7407-7416 (2012).
14. Francisco, K. R., Burgo, T. A. L., Galembeck, F. Tribocharged
Polymer Surfaces: Solvent Effect on Pattern Formation and
Modification. Chem. Lett. 41, 1256-1258 (2012).
• Procedure used to transfer charges from
PTFE to LDPE using paraffin oil as transfer
agent;
• Also, ethanol can be used to suppress
charges on a previous tribocharged PTFE
surface.
Charge transfer and
electrostatic lithograph
15. Mo<va<on
and
hypothesis
• Triboeletrifica<on:
glass
beads
over
PE
or
PTFE;
• Fric<on
generates
surfaces
with
both
posi<ve
and
nega<ve
paWerns;
• Since,
coulombian
forces
(long
range)
describe
interac<ons
between
electrical
charges,
how
these
charges
affect
fric<on
on
electrified
interfaces?
16. Tribology: science of friction
• “The
science
and
technology
of
interac<ng
surfaces
in
rela<ve
mo<on
and
of
associated
subjects
and
prac<ces.”
(Peter
Jost,
1966);
• Amontons’
laws:
– Fric,on
is
propor,onal
to
normal
load
– Independent
of
apparent
contact
area
Mate, C. M. Tribology on the small scale.
Oxford University Press, 2008.
Fall, et al. Sliding Friction on wet and dry sand.
Phys. Rev. Lett. (2014).
17. Real
contact
area
and
adhesion
• Connec<ons
from
micro
to
macro
scale
is
very
difficult;
• Real
x
apparent
contact
area;
• Elasto-‐plas<c
deforma<ons;
• Adhesion:
van
der
Waals
forces
(only???):
“…The
primary
obstacle
to
inclusion
of
sliding
triboelectrifica<on
into
our
model
is
the
mysterious
and
complex
nature
of
the
process…”
Bowden, F. P. & Tabor, D. Friction and Lubrication. 2nd ed., Oxford (1954).
Nakayama, K. Wear 194, 185-189 (1996).
Ireland, P. M. J. Electrostat. 70, 524-531 (2012).
18. Mechanical
contact:
JKR,
DMT
and
Maugis
• JKR:
Adhesion
forces
change
contact
area
• DMT:
Contact
area
remains
the
same,
but
with
addi<onal
aWrac<ve
interac<ons
• Maugis:
contact
area
is
in
between!!!
Johnson, K. L.; Kendall, K. & Roberts, A. D. Proc. R. Soc. London A (1971).
Derjaguin, B. V.; Muller, V. M. & Toporov, Y. P. J. Colloid Interface Sci. (1975).
Maugis, D. J. Colloid Interface Sci. (1992).
with adhesion
aH aH
a a
without adhesion (Hertz)
van der Waals forces
19. …and
the
Coulombic
contribu<on?
“…The primary obstacle to inclusion of sliding
triboelectrification into our model is the mysterious
and complex nature of the process…”
Ireland, P. M. J. Electrostat. (2012).
20. Coefficient
of
Rolling
Resistance
(CoRR)
x
Electrosta<c
Poten<al
A"
B" C"h
d
CoRR = h/d
glass beads
tribocharged PTFE
21. CoRR:
silanized
glass
beads
a b
θ=25˚ θ=93˚
• Rolling coefficients are strongly
modified by the surface silanitazion
of glass.
θ = 15º θ = 93º
23. Fric,on
angle:
PTFE
x
PE
• Triboelectrification
between PTFE and
PE increases
friction angles
• Some PE pellets
does not slide even
at 90º. PTFE + PE pellets
after shaking
PTFE
PTFE + PE pellets
before shaking
25. Fric<on
at
a
microscopic
level:
Lateral
Force
Microscopy
• First
verified
by
Mate
et
al.;
• AFM
plahorm;
• Deflec<on
signal
is
a
qualita<ve
measurement
of
fric<on.
http://www.doitpoms.ac.uk/tlplib/afm/lfm.php
26. α∆´ =
(1+µ2)sinθcosθ
cosθ2 − µ2 sin2θ
αW´ =
µ
cosθ2 − µ2 sin2θ
µ + =
2∆´
W´sin2θ
1
µ
LFM
calibra<on:
volts
(V)
to
units
of
force
(N)
Ogletree, D. F., Carpick, R. W. & Salmeron M.
Calibration of frictional forces in atomic force
microscopy. Rev. Sci. Instrum. 67(9), 3298-3306 (1996).
27. Lateral
force
microscopy
(LFM)
• Friction is largely affected
by surface charges at the
nanometer scale;
• Fractal dimension D of
friction signal is bigger
than topography signal!!!
28. Force-‐distance
curves
(Fd)
on
tribocharged
PTFE
In Geckos, each hair produces 100 nN (due to van der Waals and/or
capillary interactions)!!! Geim, et al. Nat. Materials (2003).
Burgo et al. Friction coefficient dependence on electrostatic tribocharging. Nature Sci. Rep.
(2013).
29. Parcial
Conclusions
• Tribocharges produced by friction have a large effect
on the friction coefficients of dielectrics:
– They may exceed all other factors for mechanical energy
dissipation;
• Controlling surface electrostatics should thus open the
way to new approaches for controlling friction in
many important systems and equipment.
• Since
tribocharge
paWerns
are
fractal,
their
contribu<on
to
fric<on
coefficients
is
also
fractal.
31. Escobar, JV, Chakravarty, A, Putterman
SJ, Diamond Relat. Mater. 2013
Akbulut M, Godfrey
Alig AR, Israelachvili
J. J. Phys. Chem. B.
2006.
Tribocurrent
35. Results Friction force fluctuations:
ü Fluctuations of friction force
occur with certain regularity in
tribological tests and Singer has
shown that this effect is generally
caused by the presence of third
bodies (material transfer).
Singer, et al., J. Vac. Sci. Technol. A 2003.
36. Tribocurrent and transient friction
force fluctuation
Although tribocurrent signal depends on speed and load, charged
species per force ratio is constant around 10 µC/N.
37. TRACK: negatively charged
Xerox® Cyan Developer powder (iGen3,
5R706). When placed on the sample, the track
promptly repeals the negatively charged toner
particles.
43. Burgo, T. A. L. & Erdemir, A.
Ang. Chem. Int. Ed., 53, 2014.
44. Concluding Remarks
n Friction force fluctuations are
always accompanied by two
tribocharging mechanisms at
metal-insulator interfaces:
– injection of electrons from the
metal to PTFE subsequently
followed by material/charge
transfer from PTFE to the metal
surface;
n Friction and triboelectrification
have a common origin:
– which must be associated with the
formation of strong electrostatic
interactions at the interface.
45. Prospects:
Controlling friction?
n The nature of the fundamental processes
that give rise to friction between sliding
bodies in close proximity is a long standing
question in tribology, both theoretically
and experimentally!!!
Park, J. Y., Ogletree, D. F., Thiel, P. A. &
Salmeron, M. Electronic control of friction in
silicon pn junctions. Science 313, 186–186
(2006).
46. Electrostatically stimulated additives?
Electrostatic potential
naturally built up at
interfaces under relative
motion should attract
charged molecules.
Moreover, an external dc
source must increase ionic
migration.
47. Tribocurrent at the nanoscale?
In progress…
AFM contact modes could be combined
with techniques for monitoring the
triboelectrification of surfaces, for
example by measuring the tribocurrent,
which would result in a powerful
complementary method to AFM.
Electrometer~
Computer
Tribocurrent image