International Journal of Engineering and Science Invention (IJESI) is an international journal intended for professionals and researchers in all fields of computer science and electronics. IJESI publishes research articles and reviews within the whole field Engineering Science and Technology, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
A Comparative Study of Low Cost Solar Based Lighting System and Fuel Based Li...IJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
A Comparative Study of Low Cost Solar Based Lighting System and Fuel Based Li...IJMER
International Journal of Modern Engineering Research (IJMER) is Peer reviewed, online Journal. It serves as an international archival forum of scholarly research related to engineering and science education.
Power Estimation for Wearable Piezoelectric Energy HarvesterTELKOMNIKA JOURNAL
The aim of this research work is to estimate the amount of electricity produced to power up wearable devices using a piezoelectric actuator, as an alternative to external power supply. A prototype of the device has been designed to continuously rotate a piezoelectric actuator mounted on a cantilever beam. A MATLAB® simulation was done to predict the amount of power harvested from human kinetic energy. Further simulation was conducted using COMSOL Multiphysics® to model a cantilever beam with piezoelectric layer. With the base excitation and the presence of tip mass at the beam, the natural frequencies and mode shapes have been analyzed to improve the amount of energy harvested. In this work, it was estimated that a maximum amount of power that could be generated is 250 μW with up to 5.5V DC output. The outcome from this research works will aid in optimising the design of the energy harvester. This research work provides optimistic possibility in harvesting sufficient energy required for wearable devices.
Unit 1 Introduction to Non-Conventional Energy ResourcesDr Piyush Charan
This unit is part of the course EC228 Renewable Energy Engineering of program B.Tech. Electronics Engg. (Solar Photovoltaic Engineering). It gives an introduction to conventional and non-conventional energy resources.
Performance analysis of wind turbine as a distributed generation unit in dist...ijcsit
In this paper, the performance analysis of wind turbine as a distributed generation unit is presented. In this
study a model of wind power is driven by an induction machine. Wind power that is distributed generation
is capable of supplying power to ac power distribution network. Wind power generation system is modeled
and simulated using Matlab Simulink software such that it can be suitable for modeling some kind of
induction generator configurations. To analyze more deeply the performance of the wind turbine system,
both normal and fault conditions scenarios have been applied. Simulation results prove the excellent
performance of the wind power unit under normal and fault conditions in the power distribution system.
This paper discusses the construction and implementation of a system for the measurement of
electrical power parameters; amperage and voltage of the hybrid system photovoltaic solar-wind, to evaluate
the system parameters and performance. The basis of the development of the measuring apparatus is the use of
an Arduino Mega 2560 to provide the interface between the electrical circuits of the sensors and the dynamics
of the voltage-amperage as well as collect data in an analog format as well as development of functional
dependence relationships. The collected data is converted into digital format and stored it in an Excel format
through the "PLX-DAQ Spreadsheet" that connects the Arduino and the PC for display and analysis of the
system parameters. The proposed technique for power measurements of AC and DC proved to be reliable and
can predict the power amperage and voltage within relative error of 1.63 % for AC and 4.16% for DC,
respectively.
Experimental study on transient response of fuel celljournalBEEI
This research work discusses a control strategy to enhance the transient response of the fuel cell and boost the real and reactive power flow from grid connected to fuel cell. The current output of the fuel cell depends on the availability of hydrogen in the fuel cell stack, a battery bank is implemented to supply the transient current and to prevent it from hydrogen saturation. The battery should only supply when there is a transient. During steady state the total power is produced by the fuel cell by regulating its hydrogen input. A prototype of the system will be created to study a control scheme which regulates the current from an input source and a battery which is connected to a dc motor. The control philosophy is based on d-q transformation and subsequently generating a reference signal that is tracked by an IGBT based inverter. The speed of the motor is controlled using pulse with modulation. The dynamic modeling of the standalone fuel cell that is connected to a dc motor is carried out using MATLAB/SIMULINK platform. The simulation results show that the control scheme works well, although the dynamic response of the system can be improved. The testing carried on the prototype proves that the concept works well, but a hydrogen control scheme should be developed to improve the efficiency of the control scheme.
Experimental Analysis of Factors Affecting the Power Output of the PV Module IJECEIAES
Energy is the driving force in all the sectors as it acts like an index of standard of living or prosperity of the people of the country. However heavy dependence on fossil fuels leads to global warming, hence there is a need for the use of clean, sustainable, and eco friendly form of energy. Among the various types of non-conventional energy solar energy is the fundamental as it is abundant, pollution free and universally available.Even though the main input to the PV system is the solar radiation still there are other factors which affects the efficiency of the pv module. In this paper real time experiment has been conducted to analyze the effect of various factors like irradiance, temperature, and angle of tilt, soiling, shading on the power output of the pv module. Temperature is a negative factor which reduces the efficiency of the module and can be reduced by various cooling arrangements. Presence of dust particles and shading obstructs the incident solar radiations entering the panel and the effect is seen in the iv and pv curve .For better performance solar tracking at maximum power point is suggested to improve the power output of the pv module.
Photoactive Additives for Crosslinking Thin Polymer Films: Inhibition of Dewe...Gregory Carroll
In this report, we describe a versatile photochemical method for cross-linking polymer films and demonstrate that
this method can be used to inhibit thin polymer films from dewetting. A bifunctional photoactive molecule featuring
two benzophenone chromophores capable of abstracting hydrogen atoms from various donors, including C-H groups,
is mixed into PS films. Upon exposure to UV light, the bis-benzophenone molecule cross-links the chains presumably
by hydrogen abstraction followed by radical recombination. Photoinduced cross-linking is characterized by infrared
spectroscopy and gel permeation chromatography. Optical and atomic force microscopy images show that
photocrosslinked polystyrene (PS) thin films resist dewetting when heated above the glass transition temperature or
exposed to solvent vapor. PS films are inhibited from dewetting on both solid and liquid substrates. The effectiveness
of the method to inhibit dewetting is studied as a function of the ratio of cross-linker to macromolecule, duration of
exposure to UV light, film thickness, the driving force for dewetting, and the thermodynamic nature of the substrate.
IOSR Journal of Applied Physics (IOSR-JAP) is an open access international journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Power Estimation for Wearable Piezoelectric Energy HarvesterTELKOMNIKA JOURNAL
The aim of this research work is to estimate the amount of electricity produced to power up wearable devices using a piezoelectric actuator, as an alternative to external power supply. A prototype of the device has been designed to continuously rotate a piezoelectric actuator mounted on a cantilever beam. A MATLAB® simulation was done to predict the amount of power harvested from human kinetic energy. Further simulation was conducted using COMSOL Multiphysics® to model a cantilever beam with piezoelectric layer. With the base excitation and the presence of tip mass at the beam, the natural frequencies and mode shapes have been analyzed to improve the amount of energy harvested. In this work, it was estimated that a maximum amount of power that could be generated is 250 μW with up to 5.5V DC output. The outcome from this research works will aid in optimising the design of the energy harvester. This research work provides optimistic possibility in harvesting sufficient energy required for wearable devices.
Unit 1 Introduction to Non-Conventional Energy ResourcesDr Piyush Charan
This unit is part of the course EC228 Renewable Energy Engineering of program B.Tech. Electronics Engg. (Solar Photovoltaic Engineering). It gives an introduction to conventional and non-conventional energy resources.
Performance analysis of wind turbine as a distributed generation unit in dist...ijcsit
In this paper, the performance analysis of wind turbine as a distributed generation unit is presented. In this
study a model of wind power is driven by an induction machine. Wind power that is distributed generation
is capable of supplying power to ac power distribution network. Wind power generation system is modeled
and simulated using Matlab Simulink software such that it can be suitable for modeling some kind of
induction generator configurations. To analyze more deeply the performance of the wind turbine system,
both normal and fault conditions scenarios have been applied. Simulation results prove the excellent
performance of the wind power unit under normal and fault conditions in the power distribution system.
This paper discusses the construction and implementation of a system for the measurement of
electrical power parameters; amperage and voltage of the hybrid system photovoltaic solar-wind, to evaluate
the system parameters and performance. The basis of the development of the measuring apparatus is the use of
an Arduino Mega 2560 to provide the interface between the electrical circuits of the sensors and the dynamics
of the voltage-amperage as well as collect data in an analog format as well as development of functional
dependence relationships. The collected data is converted into digital format and stored it in an Excel format
through the "PLX-DAQ Spreadsheet" that connects the Arduino and the PC for display and analysis of the
system parameters. The proposed technique for power measurements of AC and DC proved to be reliable and
can predict the power amperage and voltage within relative error of 1.63 % for AC and 4.16% for DC,
respectively.
Experimental study on transient response of fuel celljournalBEEI
This research work discusses a control strategy to enhance the transient response of the fuel cell and boost the real and reactive power flow from grid connected to fuel cell. The current output of the fuel cell depends on the availability of hydrogen in the fuel cell stack, a battery bank is implemented to supply the transient current and to prevent it from hydrogen saturation. The battery should only supply when there is a transient. During steady state the total power is produced by the fuel cell by regulating its hydrogen input. A prototype of the system will be created to study a control scheme which regulates the current from an input source and a battery which is connected to a dc motor. The control philosophy is based on d-q transformation and subsequently generating a reference signal that is tracked by an IGBT based inverter. The speed of the motor is controlled using pulse with modulation. The dynamic modeling of the standalone fuel cell that is connected to a dc motor is carried out using MATLAB/SIMULINK platform. The simulation results show that the control scheme works well, although the dynamic response of the system can be improved. The testing carried on the prototype proves that the concept works well, but a hydrogen control scheme should be developed to improve the efficiency of the control scheme.
Experimental Analysis of Factors Affecting the Power Output of the PV Module IJECEIAES
Energy is the driving force in all the sectors as it acts like an index of standard of living or prosperity of the people of the country. However heavy dependence on fossil fuels leads to global warming, hence there is a need for the use of clean, sustainable, and eco friendly form of energy. Among the various types of non-conventional energy solar energy is the fundamental as it is abundant, pollution free and universally available.Even though the main input to the PV system is the solar radiation still there are other factors which affects the efficiency of the pv module. In this paper real time experiment has been conducted to analyze the effect of various factors like irradiance, temperature, and angle of tilt, soiling, shading on the power output of the pv module. Temperature is a negative factor which reduces the efficiency of the module and can be reduced by various cooling arrangements. Presence of dust particles and shading obstructs the incident solar radiations entering the panel and the effect is seen in the iv and pv curve .For better performance solar tracking at maximum power point is suggested to improve the power output of the pv module.
Photoactive Additives for Crosslinking Thin Polymer Films: Inhibition of Dewe...Gregory Carroll
In this report, we describe a versatile photochemical method for cross-linking polymer films and demonstrate that
this method can be used to inhibit thin polymer films from dewetting. A bifunctional photoactive molecule featuring
two benzophenone chromophores capable of abstracting hydrogen atoms from various donors, including C-H groups,
is mixed into PS films. Upon exposure to UV light, the bis-benzophenone molecule cross-links the chains presumably
by hydrogen abstraction followed by radical recombination. Photoinduced cross-linking is characterized by infrared
spectroscopy and gel permeation chromatography. Optical and atomic force microscopy images show that
photocrosslinked polystyrene (PS) thin films resist dewetting when heated above the glass transition temperature or
exposed to solvent vapor. PS films are inhibited from dewetting on both solid and liquid substrates. The effectiveness
of the method to inhibit dewetting is studied as a function of the ratio of cross-linker to macromolecule, duration of
exposure to UV light, film thickness, the driving force for dewetting, and the thermodynamic nature of the substrate.
IOSR Journal of Applied Physics (IOSR-JAP) is an open access international journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
The PVA bulk solution was first prepared by dissolving PVA powder (5 wt %) in distilled water under controlling water bath temperature at 60-70 0C and continuous stirring for 3 hours, After the solution cooled down to ambient temperature, a concentration of (0.01and 0.03 wt%) of AgNO3 were added to solution in a darkroom and stirred for 2 hours, then the blend solution is poured into Petri dishes and allowed to dry to form films by casting under ambient temperature for 3 days in a darkroom, after draying the films were cut to 2cmx2cm and kept in black pags. The films were exposed to different doses (2, 4, 6, 8, 10 Gy) from a linear accelerator by constant energy 6 MeV with applicator cone and SSD (applicator surface distance) 50 cm, field size 10cmx10 cm. The characterization by by UV-visible spectroscopy showed that the pure PVA has an absorption peak in the range of ultraviolet at 275 nm and the absorption peak increases with radiation dose increment from 0 to 10 Gy and the composites films (PVA\AgNO3) showed an absorption peak coefficient at 420 nm (visible light) which is also increases as the radiation dose increases. Also the energy band gap of the composites irradiated films appeared to be decreases from 4.0E-19 down to 3.5E-19 eV. Moreover the optical density of the irradiated films showed significant correlation (R2 = 0.99) with the applied dose. While the tensile strength (TS) of the irradiated PVA film has been increases following the increment of radiation dose and peaking at 30 MPa at 6 Gy, then decreases as the dose increase. The study also revealed that there is a significant (R2 =96) linear proportional relationship between the absorption coefficient and the applied dose on the PVA film.
Green VTT has commitment to develop technologies for the bio-economy to benefit society through prosperity through less environmental burden. Industrial biomaterials spearhead program is targeting new value added applications on non-food related biomass in the fields of marked industrial importance, such as packaging, composites and appliances. The development is based on long research activity in the fields of biomass fractionation and converting as well deep expertise on the material sciences, converting technologies and application.
This Research Highlights focuses on novel biopolymers from forest industry side-streams that have been developed for bio-packing applications, like oxygen and grease barrier materials for fibre webs. Development of translucent and mouldable fibre based packaging and modification and regeneration of cellulose enabled new openings. The main achievement is, however, the nanocellulose development that has progressed to the international top level, enabling VTT partners to move to the industrial scale test runs and pilot decisions. Research and development in the area of industrial biomaterials has a positive impact on chemical, forest and packing industry.
Detailed description of types of plasticizers, mode of selection, types of effects produced on polymers and optimization of plasticizers in aqueous/organic coating based systems.
Effect of annealing on the structural and optical properties of nanostructure...sarmad
A thesis
Submitted to the Council of Education College of Al-mustansiriyah University in Partial Fulfillment of the Requirements for theDegree of M.Sc. in Physics
By
Sarmad Sabih Kaduory Al-Obaidi
B. Sc. 2010
Supervised By
Dr.Ali Ahmed Yousif Al-Shammari
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Power Generation Using Piezoelectric TransducerIJERA Editor
The most basic need of today’s world is energy which is non-renewable source of energy available on earth. The
need is increasing day by day, to overcome this there is requirement of energy harvesting. This paper attempts
to show how man has been utilizing and optimizing kinetic energy. Current work also illustrates the working
principle of piezoelectric crystal and various sources of vibration for the crystal. “The idea of energy harvesting
is applicable to sensors as well as transducers that are placed and operated on some entities for a long time to
replace the sensor module batteries. Such sensors are commonly called self-powered sensors.” Embarked
piezoelectric transducer, which is an electromechanical converter, undergoes mechanical vibrations therefore
produce electricity. This power source has many applications as in agriculture, home application and street
lighting and as energy source for sensors in remote locations
development of piezoelectric nano generator with super-capacitorINFOGAIN PUBLICATION
Harvesting mechanical energy from human motion is an attractive approach for obtaining clean and sustainable electric energy to power wearable sensors, which are widely used for health monitoring, activity recognition, gait analysis and so on. This paper studies a piezoelectric energy based device which conserve mechanical energy in shoes originated from human motion. The device is based on a on a pressure based energy generation. Besides, consideration is given to both high performance durability and build with repect to keeping the comfort in mind . The device provides an average output power of 1 mW during a walk at a frequency of roughly 1 Hz., a direct current (DC) power supply is built through integrating the device with a power management circuit.
Approach To Power Harvesting With Piezoelectric MaterialIJERA Editor
Nowadays, most of the research in the energy field is to develop sources of energy for the future, With oil resources being over, tapped and eventually bound to end, it is time to find renewable Piezoelectric materials are being more and more studied as they turn out to be very unusual materials with very specific and interesting properties. In fact, these materials have the ability to produce electrical energy from mechanical energy, for example, they can convert mechanical behavior like vibrations into electricity. Recent work has shown that these materials could be used as power generators, the amount of energy produced is still very low, hence the necessity to optimize them. The objective of this work is to study the all of the piezoelectric material systems and calculated the possible power generated from it, and a special case to design and build a fully functional floor tile device that when stepped on will generate enough energy to light an LED, The system will be charge a temporary energy storage device, a capacitor bank, and then use this stored energy to power an LED.
Performance of piezoelectric energy harvester with vortex-induced vibration a...TELKOMNIKA JOURNAL
Piezoelectric energy harvesters (PEHs) are a kind of energy harvester that generates electricity due to pressure or vibration. Vortex-induced vibration (VIV) is a method that utilized wind energy and bluff body to generate the vibration in PEH. The objective of this research was to study the output voltage that generates in different bluff bodies with various airflow velocities. Experimental and simulation have done in this study. Experimental used PEH that consists of piezoelectric bimorph and rectangular-trapezoid fin. Bluff bodies with various cross-sectional areas, namely rhombus, square, and triangle were set up in front of the PEH at a distance of 80 cm. The various air velocities are set up to 5, 7, and 9 m/s in the wind tunnel with a cross-section of 250 mm × 250 mm. The simulation used the finite element method in explore the fluid flow pattern. The rhombus cross-sectional bluff body can generate voltage with an average of 1.5 volts. It is more voltage generated than a square and triangle. A vortex is formed near the rhombus bluff body and generates pressure fluctuation in its wake region. This pressure fluctuation takes place until airflow hits and leads PEH to vibrate and generate the voltage.
In this presentation, basics of solar cells, what is piezoelectricity and its application, followed by basics of thermoelectricity and its application would be discussed.
State of ICS and IoT Cyber Threat Landscape Report 2024 previewPrayukth K V
The IoT and OT threat landscape report has been prepared by the Threat Research Team at Sectrio using data from Sectrio, cyber threat intelligence farming facilities spread across over 85 cities around the world. In addition, Sectrio also runs AI-based advanced threat and payload engagement facilities that serve as sinks to attract and engage sophisticated threat actors, and newer malware including new variants and latent threats that are at an earlier stage of development.
The latest edition of the OT/ICS and IoT security Threat Landscape Report 2024 also covers:
State of global ICS asset and network exposure
Sectoral targets and attacks as well as the cost of ransom
Global APT activity, AI usage, actor and tactic profiles, and implications
Rise in volumes of AI-powered cyberattacks
Major cyber events in 2024
Malware and malicious payload trends
Cyberattack types and targets
Vulnerability exploit attempts on CVEs
Attacks on counties – USA
Expansion of bot farms – how, where, and why
In-depth analysis of the cyber threat landscape across North America, South America, Europe, APAC, and the Middle East
Why are attacks on smart factories rising?
Cyber risk predictions
Axis of attacks – Europe
Systemic attacks in the Middle East
Download the full report from here:
https://sectrio.com/resources/ot-threat-landscape-reports/sectrio-releases-ot-ics-and-iot-security-threat-landscape-report-2024/
Accelerate your Kubernetes clusters with Varnish CachingThijs Feryn
A presentation about the usage and availability of Varnish on Kubernetes. This talk explores the capabilities of Varnish caching and shows how to use the Varnish Helm chart to deploy it to Kubernetes.
This presentation was delivered at K8SUG Singapore. See https://feryn.eu/presentations/accelerate-your-kubernetes-clusters-with-varnish-caching-k8sug-singapore-28-2024 for more details.
Transcript: Selling digital books in 2024: Insights from industry leaders - T...BookNet Canada
The publishing industry has been selling digital audiobooks and ebooks for over a decade and has found its groove. What’s changed? What has stayed the same? Where do we go from here? Join a group of leading sales peers from across the industry for a conversation about the lessons learned since the popularization of digital books, best practices, digital book supply chain management, and more.
Link to video recording: https://bnctechforum.ca/sessions/selling-digital-books-in-2024-insights-from-industry-leaders/
Presented by BookNet Canada on May 28, 2024, with support from the Department of Canadian Heritage.
Neuro-symbolic is not enough, we need neuro-*semantic*Frank van Harmelen
Neuro-symbolic (NeSy) AI is on the rise. However, simply machine learning on just any symbolic structure is not sufficient to really harvest the gains of NeSy. These will only be gained when the symbolic structures have an actual semantics. I give an operational definition of semantics as “predictable inference”.
All of this illustrated with link prediction over knowledge graphs, but the argument is general.
Builder.ai Founder Sachin Dev Duggal's Strategic Approach to Create an Innova...Ramesh Iyer
In today's fast-changing business world, Companies that adapt and embrace new ideas often need help to keep up with the competition. However, fostering a culture of innovation takes much work. It takes vision, leadership and willingness to take risks in the right proportion. Sachin Dev Duggal, co-founder of Builder.ai, has perfected the art of this balance, creating a company culture where creativity and growth are nurtured at each stage.
Connector Corner: Automate dynamic content and events by pushing a buttonDianaGray10
Here is something new! In our next Connector Corner webinar, we will demonstrate how you can use a single workflow to:
Create a campaign using Mailchimp with merge tags/fields
Send an interactive Slack channel message (using buttons)
Have the message received by managers and peers along with a test email for review
But there’s more:
In a second workflow supporting the same use case, you’ll see:
Your campaign sent to target colleagues for approval
If the “Approve” button is clicked, a Jira/Zendesk ticket is created for the marketing design team
But—if the “Reject” button is pushed, colleagues will be alerted via Slack message
Join us to learn more about this new, human-in-the-loop capability, brought to you by Integration Service connectors.
And...
Speakers:
Akshay Agnihotri, Product Manager
Charlie Greenberg, Host
Epistemic Interaction - tuning interfaces to provide information for AI supportAlan Dix
Paper presented at SYNERGY workshop at AVI 2024, Genoa, Italy. 3rd June 2024
https://alandix.com/academic/papers/synergy2024-epistemic/
As machine learning integrates deeper into human-computer interactions, the concept of epistemic interaction emerges, aiming to refine these interactions to enhance system adaptability. This approach encourages minor, intentional adjustments in user behaviour to enrich the data available for system learning. This paper introduces epistemic interaction within the context of human-system communication, illustrating how deliberate interaction design can improve system understanding and adaptation. Through concrete examples, we demonstrate the potential of epistemic interaction to significantly advance human-computer interaction by leveraging intuitive human communication strategies to inform system design and functionality, offering a novel pathway for enriching user-system engagements.
Smart TV Buyer Insights Survey 2024 by 91mobiles.pdf91mobiles
91mobiles recently conducted a Smart TV Buyer Insights Survey in which we asked over 3,000 respondents about the TV they own, aspects they look at on a new TV, and their TV buying preferences.
GraphRAG is All You need? LLM & Knowledge GraphGuy Korland
Guy Korland, CEO and Co-founder of FalkorDB, will review two articles on the integration of language models with knowledge graphs.
1. Unifying Large Language Models and Knowledge Graphs: A Roadmap.
https://arxiv.org/abs/2306.08302
2. Microsoft Research's GraphRAG paper and a review paper on various uses of knowledge graphs:
https://www.microsoft.com/en-us/research/blog/graphrag-unlocking-llm-discovery-on-narrative-private-data/
Slack (or Teams) Automation for Bonterra Impact Management (fka Social Soluti...Jeffrey Haguewood
Sidekick Solutions uses Bonterra Impact Management (fka Social Solutions Apricot) and automation solutions to integrate data for business workflows.
We believe integration and automation are essential to user experience and the promise of efficient work through technology. Automation is the critical ingredient to realizing that full vision. We develop integration products and services for Bonterra Case Management software to support the deployment of automations for a variety of use cases.
This video focuses on the notifications, alerts, and approval requests using Slack for Bonterra Impact Management. The solutions covered in this webinar can also be deployed for Microsoft Teams.
Interested in deploying notification automations for Bonterra Impact Management? Contact us at sales@sidekicksolutionsllc.com to discuss next steps.
When stars align: studies in data quality, knowledge graphs, and machine lear...
A03430105
1. International Journal of Engineering Science Invention
ISSN (Online): 2319 – 6734, ISSN (Print): 2319 – 6726
www.ijesi.org Volume 3 Issue 4 ǁ April 2014 ǁ PP.01-05
www.ijesi.org 1 | Page
Review: Polymers In Energy Harvesting
Susmita Dey Sadhu1*, Sidhharth Chakraborty1, Minakshi Garg2 and
Shivani G. Varmani3
1
Dept. Of Polymer Science, Bhaskaracharya College of Applied Sciences (University of Delhi),
Sector-2, Dwarka, New Delhi 110075
2
Dept. Of Food Technology, Bhaskaracharya College of Applied Sciences (University of Delhi),
Sector-2, Dwarka, New Delhi 110075
3
Dept. Of Biomedical Sciences, Bhaskaracharya College of Applied Sciences (University of Delhi),
Sector-2, Dwarka, New Delhi 110075
ABSTARCT: Researchers around the globe, are continuously looking towards the fundamentals for energy
conservation and storage. In this paper we shall take a look at the efforts made by various researchers in this
field of energy harvesting and it's storage. On searching the literature, it is notice that a lot of work has been
done in the field of Piezoelectric materials and studies made in this area. Scientists also found that energy can
also be harvested to power small autonomous sensors such as those developed using MEMS (micro
electromechanical systems) wherein the power is generated through polymer made capacitors or super-
capacitors. Thus in this paper we shall review few scientific works, made with the idea regarding-”how to
harvest energy through polymer materials”.
KEY WORDS: Energy Harvesting, Polymer, Piezoelectric, Renewable energy
I. INTRODUCTION
The need and demand for energy is ever increasing. There are many sources of energy which are losing
(leaking, for example-the human body) energy in a dynamic (continuous) way. This need for energy can be
compensated through these leaking energy resources. Apart from these leaking sources, natural sources such as
the sunlight and the vapours of water, which can be found in our atmosphere are proved to be a boon for
mankind. This paper deals with the aspects of introduction of polymers in the field of energy harvesting.
Recycling of the used energy has been discussed by almost all the researchers till now. This can be achieved by
working towards the creation of a capacitor out of a suitable polymeric material and the usable energy available
for recycling.
We know that any vibration can be transported through a medium which may be converted into the
form of an useful energy for other purposes. This basic principle of energy harvesting is used for developing
methods of energy harvesting [1]. Different research groups have tried to work in various directions to reach to
the final destination of energy regeneration.
In this direction researchers found the human body as an ample source of vibrations and tried to find a
way to store the energy generated from these vibrations [2]. The next breakthrough in the field of harvesting
energy is via. Hyperbranched polymers [3-6]. Researchers have shown that photons when radiated to the
periphery of a polymer (hyperbranched), it is able to pass the very same energy through its branches towards the
center of the polymer and thus is able to store it. This way it may work like a capacitor [7-8]. The next
advancement has been made in the field of energy generation through water vapour, where steam has been
utilized to generate motion which in turn can generate kinetic energy.
1.1. Review Of Literature And Discussion
As discussed in the Introduction, the methods used for energy harvesting using polymers can be discussed under
the following categories:
A) Through Piezoelectric Generators [2-7]:
Piezoelectricity is the ability of certain crystals to generate electricity in response to applied mechanical
stress. In this method, this property has been used to generate energy. This method is getting more popular
because the performance of piezo generators has been boosted and low power consumption semiconductor
controllers have emerged. Usually in most of the cases polymers such as Tantalum-Polymer, PVDF (poly
vinyledene flouride) etc. have been used to make a thin strip which acts under the action of electromagnetic
2. Review: Polymers In Energy Harvesting
www.ijesi.org 2 | Page
vibration. The film/strip is used as energy harvester and energy is being imparted to it via electromagnet which
causes oscillations in the strip. These oscillations are subsequently converted into electrical energy. This
electricity is obtained in the form of alternating current which is converted to direct current by a rectifier. This
energy in form of current is passed through a capacitor and thus we are able to prepare a storage bank for
electricity.
There are two types of piezoelectric signals that can be used for technological applications:
1) The direct piezoelectric effect that describes the ability of a given material to transform mechanical strain
into electrical signals. The direct piezoelectric effect is more suitable for sensor applications
2) The converse effect of the predecessor which is the ability to convert an applied electrical energy into
mechanical energy. This ability of piezoelectric signals is required for actuator applications (actuators are
devices which convert applied energy or pressure into motion).
Now, the following discussion will give us an insight into the details of harvesting energy with the help
piezoelectricity and how researchers globally follow the trend to create energy harvesting prototypes.
The process of preparing the piezoelectric generator consists of the following steps:
a) Preparation of polymer through which piezoelectricy can be harnessed
The piezoelectric films used for the energy generation are constituted by a polymeric material coated in
both sides by a conducting material, which form the electrodes. The polymeric material is based on its
electroactive phase (electric sensitive polymer regions). It can be processed in the form of a film by extrusion,
injection or from the solution. To obtain the electroactive phase, the phase films must be submitted to
mechanical stretching at generally higher temperatures. The main advantages of using polymeric films instead
of piezoceramics or single crystals are that polymer films are flexible and can be fabricated in the desired shapes
and sizes through simple processing processes. Moreover, electroactive polymers are very cheap in comparison
with the ceramic and single crystal counterparts, making them more suitable for mass production systems and
devices. A final step of stretching at a temperature around 80⁰ C results in oriented films, which further
increases the material performance.
(b) Electrode deposition over the polymeric strip to make the strip responsive towards electromagnetic
induction [8]
When the material is prepared, electr- deposition is done on both sides by magnetron sputtering or by
thermal evaporation. (generally Steel and Aluminum have been used as electrode materials for the present date
research purposes)
(c) Positioning of the piezoelectric material near a readily available source of vibrations [12]
Since, piezoelectricity is a dynamic process, hence, a piezoelectricity can be harnessed from sources
where energy is draining out steadily. One such source is our body. Be it the heart, hand, legs or any other body
part, all are draining energy in some way or the other. The material should be positioned in the places were
larger and more variable pressure is exerted during walking.
(d) Electronic circuit to obtain a direct current from the alternating current generated by making it
pass through a rectifier. Simultaneously joining it to a capacitor as well [13]
In order to maximize the energy transfer to a charge or to a battery, in the case of energy storage, a
rectifying circuit is necessary in order to obtain a single polarity voltage. The whole system is implemented into
a shoe and further tests are performed in real walking situations.
(e) Energy storage devices such as a rechargeable battery can be implemented in lieu of a capacitor, so
as to improve the energy storage capabilities [8]
A thin-film rechargeable lithium battery can be used to store the energy generated. A layered structure,
as presented is being prepared to implement the proposed battery as suggested by the researchers.
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(B) Light Energy Harvesting In Dendrimers and Hyperbranch Polymers
It deals with photon capture abilities of highly branched polymers when subjected to light (generally
sunlight). Moreover the capability of the polymer to retain the absorbed photon is very important. With the
facility to accommodate a proliferation of antenna chromophores, such materials can capture and channel light
energy with a high degree of efficiency, each polymer unit potentially delivering the energy of one photon—or
more, when optical nonlinearity is involved. Let us focus on the underlining facts behind the accumulation of
energy from such polymers. This shall give us an idea about the development done by scientists in the field of
light energy harvesting.
(a) Step-wise Energy Transfer [14]
Chromophores are the basic building blocks for energy harvesting through light energy. For the
efficient absorption of radiation, the antenna chromophores of light-harvesting dendrimers, commonly the
species from which the polymer is constructed, should display strong absorption in a suitable part of the
electromagnetic spectrum—generally the visible range of solar radiation that retains significant intensity after
passage through the Earth’s atmosphere. A device similar to the synthetic material may be designed with the
help of photobiological systems which commonly have chromophores for enhanced and effective absorption.
Photobiological and dendrimeric systems deploy similar energy harvesting mechanisms in photon absorption
and energy transfer to a central trap. The photochemical features which they share include- i) multiple
peripheral chromophores that can initially absorb light, producing short-lived electronic excited states; a
mechanism for rapid transfer of the resulting excitation towards a trapping site (stepwise resonance energy
transfer, RET), ii) a layout that fastens trap-directed absorption, governed by chromophore orientation, and iii) a
process for collecting and capturing the energy acquired at the trap. In the construction of light-harvesting
dendrimers, each of these photochemical and photophysical principles are put to highly effective use. The
repeated branching of the polymer structure, together with the three-dimensional folding that occurs in all but
the smallest systems, supports a special proliferation of chromophores on the outermost surface, and the inner,
building-block chromophores act with high efficiency as transient hosts for the excitation energy to the core.
Moreover, the convergence of the dendrimer branches towards the core also assists the pooling of energy, in the
event that more than one photon is initially captured upon the outer surface.
(b) Directed Energy Transfer [9]
As we know that energy transfer through chromophores is a step-wise and continuous process but it has
certain drawbacks to it during transfer of resonance energy. Enegy that is being lost to the surroundings does not
reach the core region of the hyperbranched polymers and hence the core does not experience maximum energy
which was present initially.
Thus rather than transferring energy to the core regions, researchers manipulated the structure of such
polymers so that maximum of the polymer structure is exposed to the radiations. This has helped in reducing the
energy loss to a large extent and helped in utilising maximum out of the radiant energy source.
In relatively small dendrimers, it is statistically unlikely for two or more excitations to co-exist at
the same time in the whole structure. Generally, the timescale for energy delivery from the antenna to the core is
shorter than the interval between successive photon capture events—the latter being a time dependent on
the irradiance, absorption frequency and σ the net absorption cross-section of the entire dendrimer.
However in larger systems, where trapping also involves a greater number of energy transfer steps, this
is no longer necessarily the case. Indeed, if the intensity of ambient sunlight is amplified by focusing down to
the diffraction limit, the simultaneous presence of two photon energies can then become significant on the
picosecond timescale associated with ultrafast trapping. A good example of supporting experimental evidence is
the cis-to-trans isomerisation observed on infrared absorption in large arylether azodendrimers, for which the
energetic considerations demand that two (or more) infrared photon energies have to be involved.
(C) Electricity From A Readily Available Source Like Water Vapour [15]:
Researchers have developed a new bio-polymeric film that is able to generate electricity from a readily
available source: water vapour. The material changes its shape as it absorbs evaporated water. As the bio-
polymer film repeatedly curls and unfurls it drives robotic limbs, which in turn generate enough electricity to
power micro- and nanoelectronic devices.
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With a sensor powered by a battery, you have to replace it periodically. If you have this device, you can harvest
energy from the environment so you don't have to replace it very often.
The Process of energy generation consists of the following steps:
(a) Harvesting energy
The new film is made from an interlocking network of two different polymers. One of the polymers -
polypyrrole, forms a hard but flexible matrix that provides structural support. The other polymer - polyol-borate,
is a soft gel that swells when it absorbs water.
The film harvests energy in the water gradient between dry and water-rich environments. When the 20-
micrometer-thick film lies on a surface that contains even a small amount of moisture, the bottom layer absorbs
evaporated water, forcing the film to curl away from the surface. Once the bottom of the film is exposed to air, it
quickly releases the moisture, somersaults forward, and starts to curl up again. As this cycle is repeated, the
continuous motion converts the chemical energy of the water gradient into mechanical energy.
Such films could act as actuators (a type of motor) or generators. As an actuator, the material can be
surprisingly powerful: The researchers demonstrated that a 25-milligram film can lift a load of glass slides 380
times its own weight, or transport a load of silver wires 10 times its own weight, by working as a potent water-
powered ―mini tractor.‖ Using only water as an energy source, this film could replace the electricity-powered
actuators now used to control small robotic limbs.
(b) Generating electricity
The mechanical energy generated by the material can also be converted into electricity by coupling the
polymer film with a piezoelectric material, which converts mechanical stress to an electric charge. This system
can generate an average power of 5.6 nanowatts, which can be stored in capacitors to power ultra-low-power
microelectronic devices, such as temperature and humidity sensors.
If used to generate electricity on a larger scale, the film could harvest energy from the environment —
for example, while placed above a lake or river. Or, it could be attached to clothing, where the mere evaporation
of sweat could fuel devices such as physiological monitoring sensors. ―You could be running or exercising and
generating power,‖ as researchers say .
On a smaller scale, the film could power microelectricalmechanical systems (MEMS), including
environmental sensors, or even smaller devices, such as nanoelectronics. The researchers are now working to
improve the efficiency of the conversion of mechanical energy to electrical energy, which could allow smaller
films to power larger devices.
Figure 1: General process of curling and uncurling of polymer film under the action of water vapour.
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II. CONCLUSIONS
On going through the above discussion, it may be concluded that the major source for energy recreation
is via vibrations. Since polymeric strips have been discussed, therefore their higher capacitance and internal
resistance are of utmost importance, while keeping in mind the main objective i.e. energy harvesting. Moreover
the generation and storage are important. Therefore an entire circuit needs to be drawn so that the energy which
has been harvested can be used to run other general appliances. Thus accomplishing both the harvesting and
storage part, researchers have achieved a way to counter the energy demand for the further applications.
The most basic property of Aryl based polymeric compounds is successive Resonance. This proved to
be a very useful property for absorbing energy from the radiated light and then pass the very same energy
towards the core area of the polymer, where it could be stored for a longer period of time.
In the third process of energy generation, a direct motion has been created so that this motion in turn
shall be able to run other appliances. A continuous folding and unfolding of polymers on absorption and release
of water vapour has been the new field of research for the scientists.
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