Tool marks: definitions and introduction; Types: compression, striated, combination of compression and striated, repeated marks; Class characteristics and individual characteristics; Tracing and lifting of marks
Introduction to the non destructive testing explains the methods for evaluating and verifying many types of Materials as plastics, structures, metals, chemicals, leakage, physical properties. It's very used in the concrete engineering world and in the scientific world.
Tool marks evidence plays an important role in forensic science. Tool marks are impressions or marks left on surfaces by tools and can be used to identify the specific tool that made the mark. There are different types of tool marks such as impressions, abrasions, cuts, and drill holes. Tool marks contain both class characteristics common to groups of tools and unique individual characteristics. Tool marks are collected using methods like photography, casting, and test marks. Examiners compare both class and individual characteristics of tool marks using various techniques like microscopy and superimposition to determine if two marks have a common origin.
Materials are tested to ensure quality, evaluate properties, prevent failure, and allow for informed material choices. There are two main types of material testing: mechanical tests which physically destroy samples to determine properties like strength; and non-destructive tests which inspect samples before use. Common tests include hardness testing using indenters, tensile testing to measure properties under load, and various non-destructive techniques like penetrant, magnetic particle, eddy current, ultrasonic, and radiographic testing to identify surface or internal flaws without damaging the sample.
This document discusses several non-destructive testing (NDT) techniques used in engineering: penetrant testing uses dyes to find surface flaws, magnetic particle testing uses magnetism to detect near-surface flaws in ferrous metals, eddy current testing uses electromagnetic induction to inspect non-ferrous metals, ultrasonic testing uses sound waves to locate internal flaws similarly to sonar, and radiography uses X-rays to image internal flaws. NDT allows inspection of valuable components without destroying them.
Quality control involves measuring quality characteristics of products and comparing them to standards to identify any deviations. Quality assurance provides confidence that quality achieved meets standards. Key quality documents include the quality assurance plan (QAP), welding procedure specification (WPS), and erection welding schedule (EWS). The QAP outlines inspection stages while the WPS defines welding parameters and the EWS details welding and non-destructive testing requirements. Non-destructive testing methods like radiography, ultrasonic testing, liquid penetrant testing, and magnetic particle inspection are used to identify flaws without damaging materials. Proper preheating, post heating, and post weld heat treatment are important to reduce welding defects and residual stresses.
Weld probe presentation- Given at COTEQ, Porto Galinhas, Brazil, June 2013John Hansen
This document discusses the advantages of using eddy current technology and specialized weld probes for weld inspection. It provides background on the development of weld probes and how they work. Weld probes allow inspection of welds through coatings with minimal lift-off sensitivity. They are well-suited for difficult-access inspections and have various applications in industries like offshore, nuclear, and rail. The document also covers standardization, equipment used, and concludes that weld probes provide a good alternative to other NDT methods for weld inspection.
Introduction to the non destructive testing explains the methods for evaluating and verifying many types of Materials as plastics, structures, metals, chemicals, leakage, physical properties. It's very used in the concrete engineering world and in the scientific world.
Tool marks evidence plays an important role in forensic science. Tool marks are impressions or marks left on surfaces by tools and can be used to identify the specific tool that made the mark. There are different types of tool marks such as impressions, abrasions, cuts, and drill holes. Tool marks contain both class characteristics common to groups of tools and unique individual characteristics. Tool marks are collected using methods like photography, casting, and test marks. Examiners compare both class and individual characteristics of tool marks using various techniques like microscopy and superimposition to determine if two marks have a common origin.
Materials are tested to ensure quality, evaluate properties, prevent failure, and allow for informed material choices. There are two main types of material testing: mechanical tests which physically destroy samples to determine properties like strength; and non-destructive tests which inspect samples before use. Common tests include hardness testing using indenters, tensile testing to measure properties under load, and various non-destructive techniques like penetrant, magnetic particle, eddy current, ultrasonic, and radiographic testing to identify surface or internal flaws without damaging the sample.
This document discusses several non-destructive testing (NDT) techniques used in engineering: penetrant testing uses dyes to find surface flaws, magnetic particle testing uses magnetism to detect near-surface flaws in ferrous metals, eddy current testing uses electromagnetic induction to inspect non-ferrous metals, ultrasonic testing uses sound waves to locate internal flaws similarly to sonar, and radiography uses X-rays to image internal flaws. NDT allows inspection of valuable components without destroying them.
Quality control involves measuring quality characteristics of products and comparing them to standards to identify any deviations. Quality assurance provides confidence that quality achieved meets standards. Key quality documents include the quality assurance plan (QAP), welding procedure specification (WPS), and erection welding schedule (EWS). The QAP outlines inspection stages while the WPS defines welding parameters and the EWS details welding and non-destructive testing requirements. Non-destructive testing methods like radiography, ultrasonic testing, liquid penetrant testing, and magnetic particle inspection are used to identify flaws without damaging materials. Proper preheating, post heating, and post weld heat treatment are important to reduce welding defects and residual stresses.
Weld probe presentation- Given at COTEQ, Porto Galinhas, Brazil, June 2013John Hansen
This document discusses the advantages of using eddy current technology and specialized weld probes for weld inspection. It provides background on the development of weld probes and how they work. Weld probes allow inspection of welds through coatings with minimal lift-off sensitivity. They are well-suited for difficult-access inspections and have various applications in industries like offshore, nuclear, and rail. The document also covers standardization, equipment used, and concludes that weld probes provide a good alternative to other NDT methods for weld inspection.
Experimental analysis of various pcs by spark testingSumit Dharmarao
This document summarizes an experimental analysis conducted to determine the carbon content of various plain carbon steels using spark testing. Six different grades of carbon steel were tested: C8, C18, C40, C45, C55, and C95. Samples were ground against an abrasive wheel and the resulting spark emissions were recorded with photos and video. Image analysis software was used to measure spark length and angle. Testing showed that higher carbon content steels produced shorter, more angled spark emissions. A manual was created cataloging the spark patterns of each steel grade, which can be used to identify unknown steel samples based on their spark properties. Conducting spark testing provides a low-cost, easy method for determining carbon steel grades
1. The document discusses techniques for restoring obliterated marks on items like vehicles and firearms for identification purposes. 2. It describes different types of marks like cast, engraved, and punched marks and principles of restoration using chemical reagents that dissolve strained metal at different rates. 3. The techniques discussed involve cleaning surfaces, taking photographs, applying etchants like acids selectively to restore serial numbers, and preserving restored marks.
Tool marks are impressions left on a softer surface by a tool due to forcible contact. They can be individually unique due to wear and tear on tools. There are four main types of tool marks: compression, striated, combination, and repetitive/multi-stroke marks. Tool marks are examined based on their class, sub-class, and individual characteristics. Proper collection involves photography, tracing, and lifting impressions. A variety of chemical reagents can be used to restore obliterated tool marks on different material surfaces like metals, wood, leather, and rubber.
This document provides contact information for product inquiries in the United States for ESSC Group. Specifically, it lists the name, address, phone number and email for Kelly Keeling at CLC International, Inc in Nappanee, IN who is the warehouse distributor in North America. It also provides the name, address, phone number and email for Steven Y. Zhang who is the sales and distribution partner located in Wooster, OH.
This chapter provides information on assessing welds through destructive and non-destructive testing. Destructive testing involves mechanical tests that require specimen preparation and destruction, while non-destructive testing techniques like visual inspection, liquid penetrant, magnetic particle, radiography, and ultrasonic inspection do not destroy the weldment. The chapter also discusses evaluating weld properties such as hardness, tensile strength, toughness, fatigue resistance, and corrosion resistance which are important for selecting appropriate welds for different applications.
FEC is an ISO 9001 certified company that manufactures and supplies a range of filter and materials testing equipment. It has over 25 years of experience in testing equipment and training according to national and international standards. FEC has an in-house R&D center that uses latest technologies to continuously improve its equipment and test methods. It offers automatic and digital equipment to test properties such as tensile strength, compression strength, impact resistance, coating thickness, and more according to standards like ISO, ASTM, and BIS.
This document provides an introduction to nondestructive testing (NDT) by defining NDT, describing the six most common NDT methods (visual inspection, liquid penetrant testing, magnetic particle testing, ultrasonic testing, eddy current testing, and radiography), and giving examples of common NDT applications in various industries. NDT allows inspection or measurement of materials, components, and structures without causing damage and is used across industries for applications like flaw detection, leak detection, and dimensional measurements.
This document provides an introduction to nondestructive testing (NDT) by defining NDT, describing the six most common NDT methods (visual inspection, liquid penetrant testing, magnetic particle testing, ultrasonic testing, eddy current testing, and radiography), and giving examples of common NDT applications in various industries. NDT allows inspection or measurement of materials, components, and structures without causing damage and is used across various stages of production and in-service to evaluate integrity and detect issues like flaws, leaks, and damage.
This document provides an introduction to nondestructive testing (NDT) including common NDT methods and applications. It defines NDT as using noninvasive techniques to determine the integrity of a material without causing harm. The six most common NDT methods are described as visual inspection, liquid penetrant testing, magnetic particle testing, ultrasonic testing, eddy current testing, and radiography. NDT is used across many industries to inspect materials and components during production and in-service for flaws and damage without impairing future usefulness or serviceability.
This document provides an introduction to nondestructive testing (NDT) by defining NDT, describing the six most common NDT methods (visual inspection, liquid penetrant testing, magnetic particle testing, ultrasonic testing, eddy current testing, and radiography), and giving examples of common NDT applications in various industries. NDT allows inspection or measurement of materials, components, and structures without causing damage and is used across industries for applications like flaw detection, leak detection, and dimensional measurements.
This document provides an introduction to nondestructive testing (NDT) by defining NDT, describing the six most common NDT methods (visual inspection, liquid penetrant testing, magnetic particle testing, ultrasonic testing, eddy current testing, and radiography), and giving examples of common NDT applications in various industries. NDT allows inspection or measurement of materials, components, and structures without causing damage and is used across industries for applications like flaw detection, leak detection, and dimensional measurements.
This document discusses non-destructive testing (NDT) methods. It begins by defining NDT as techniques used to evaluate materials without causing damage. It then lists common NDT types like visual inspection, liquid penetrant, ultrasonic, and radiographic testing. For each type, it provides a brief overview of the principles and applications. The document focuses on liquid penetrant testing, describing the procedure and noting it is useful for inspecting parts like aircraft wheels and automotive pistons. It also discusses advantages of NDT like avoiding failures and ensuring safety. In conclusion, it states that NDT can save costs for facilities that implement its methods properly.
This document provides an overview of non-destructive testing (NDT) methods. It describes six common NDT methods - visual inspection, liquid penetrant inspection, magnetic particle inspection, radiography, eddy current testing, and ultrasonic inspection. For each method it explains the basic principles, advantages, limitations and applications for inspecting materials and detecting flaws without causing damage. NDT methods are used at various stages of production and service to evaluate integrity and detect issues in a wide range of industries.
IRJET-Analysis and Optimization of Cutting Parameters in Turning using Tic -...IRJET Journal
This document analyzes and optimizes cutting parameters in turning chrome-moly alloy steel using TiC-coated carbide inserts. Twenty-seven experiments were conducted using a L27 orthogonal design to evaluate the effects of cutting speed, feed rate, and depth of cut on surface roughness, power consumption, chip reduction coefficient, and tool wear. The results show that feed rate and depth of cut significantly affect surface roughness, while cutting speed, depth of cut, and feed rate influence power consumption and tool wear. Optimizing these cutting parameters can improve the machining performance and surface quality when hard turning chrome-moly alloy steel.
The document discusses serial number restoration. It explains that serial numbers are unique identifiers applied by manufacturers to objects like firearms. Criminals sometimes obliterate serial numbers to avoid identification. Restoration involves polishing the surface and using acid to etch away layers of metal, revealing the original serial number imprint beneath. The restored number is then documented through writing or photos. The process helps identify stolen objects by recovering the obscured identifying marks.
This document provides an overview of non-destructive testing (NDT) methods and their applications. It defines NDT as using noninvasive techniques to inspect materials and structures without causing harm. The five most common NDT methods are outlined as liquid penetrant, magnetic, ultrasonic, eddy current, and radiography. Examples of applications discussed include inspecting raw materials and structures for defects, inspecting aircraft and bridges for cracks or corrosion, and monitoring pipes, tanks, and power plant equipment during operation for damage or wear. Regular inspections using NDT help prevent failures in critical infrastructure and ensure safety.
Non destructive test in concrete in building construction architectureAditya Sanyal
This document discusses non-destructive testing methods for concrete, including rebound hammer testing and ultrasonic pulse velocity testing. It explains that non-destructive testing allows evaluation of concrete properties like strength and homogeneity without damaging the structure. Some benefits are lower cost compared to destructive testing and ability to test both new and existing structures. Common non-destructive tests described include rebound hammer, ultrasonic pulse velocity, permeability, and covermeter tests.
This document discusses various welding defects such as slag inclusion, undercut, porosity, incomplete fusion, overlap, underfill, spatter, excessive convexity, incomplete penetration, and excessive penetration. It provides the causes and ways to prevent or repair each defect. Nondestructive and destructive testing methods for inspecting welds are also summarized, including visual inspection, ultrasonic testing, radiographic testing, dye penetrant testing, magnetic particle testing, and mechanical tests.
This document provides an introduction to nondestructive testing (NDT) methods. It defines NDT as using noninvasive techniques to determine the integrity of a material or structure without causing damage. Six common NDT methods are described: visual inspection, liquid penetrant testing, magnetic particle testing, ultrasonic testing, eddy current testing, and radiography. Examples are given of how NDT is used to inspect aircraft, bridges, pipelines and other structures and components during manufacturing and operation to detect flaws and ensure safety and integrity.
Experimental analysis of various pcs by spark testingSumit Dharmarao
This document summarizes an experimental analysis conducted to determine the carbon content of various plain carbon steels using spark testing. Six different grades of carbon steel were tested: C8, C18, C40, C45, C55, and C95. Samples were ground against an abrasive wheel and the resulting spark emissions were recorded with photos and video. Image analysis software was used to measure spark length and angle. Testing showed that higher carbon content steels produced shorter, more angled spark emissions. A manual was created cataloging the spark patterns of each steel grade, which can be used to identify unknown steel samples based on their spark properties. Conducting spark testing provides a low-cost, easy method for determining carbon steel grades
1. The document discusses techniques for restoring obliterated marks on items like vehicles and firearms for identification purposes. 2. It describes different types of marks like cast, engraved, and punched marks and principles of restoration using chemical reagents that dissolve strained metal at different rates. 3. The techniques discussed involve cleaning surfaces, taking photographs, applying etchants like acids selectively to restore serial numbers, and preserving restored marks.
Tool marks are impressions left on a softer surface by a tool due to forcible contact. They can be individually unique due to wear and tear on tools. There are four main types of tool marks: compression, striated, combination, and repetitive/multi-stroke marks. Tool marks are examined based on their class, sub-class, and individual characteristics. Proper collection involves photography, tracing, and lifting impressions. A variety of chemical reagents can be used to restore obliterated tool marks on different material surfaces like metals, wood, leather, and rubber.
This document provides contact information for product inquiries in the United States for ESSC Group. Specifically, it lists the name, address, phone number and email for Kelly Keeling at CLC International, Inc in Nappanee, IN who is the warehouse distributor in North America. It also provides the name, address, phone number and email for Steven Y. Zhang who is the sales and distribution partner located in Wooster, OH.
This chapter provides information on assessing welds through destructive and non-destructive testing. Destructive testing involves mechanical tests that require specimen preparation and destruction, while non-destructive testing techniques like visual inspection, liquid penetrant, magnetic particle, radiography, and ultrasonic inspection do not destroy the weldment. The chapter also discusses evaluating weld properties such as hardness, tensile strength, toughness, fatigue resistance, and corrosion resistance which are important for selecting appropriate welds for different applications.
FEC is an ISO 9001 certified company that manufactures and supplies a range of filter and materials testing equipment. It has over 25 years of experience in testing equipment and training according to national and international standards. FEC has an in-house R&D center that uses latest technologies to continuously improve its equipment and test methods. It offers automatic and digital equipment to test properties such as tensile strength, compression strength, impact resistance, coating thickness, and more according to standards like ISO, ASTM, and BIS.
This document provides an introduction to nondestructive testing (NDT) by defining NDT, describing the six most common NDT methods (visual inspection, liquid penetrant testing, magnetic particle testing, ultrasonic testing, eddy current testing, and radiography), and giving examples of common NDT applications in various industries. NDT allows inspection or measurement of materials, components, and structures without causing damage and is used across industries for applications like flaw detection, leak detection, and dimensional measurements.
This document provides an introduction to nondestructive testing (NDT) by defining NDT, describing the six most common NDT methods (visual inspection, liquid penetrant testing, magnetic particle testing, ultrasonic testing, eddy current testing, and radiography), and giving examples of common NDT applications in various industries. NDT allows inspection or measurement of materials, components, and structures without causing damage and is used across various stages of production and in-service to evaluate integrity and detect issues like flaws, leaks, and damage.
This document provides an introduction to nondestructive testing (NDT) including common NDT methods and applications. It defines NDT as using noninvasive techniques to determine the integrity of a material without causing harm. The six most common NDT methods are described as visual inspection, liquid penetrant testing, magnetic particle testing, ultrasonic testing, eddy current testing, and radiography. NDT is used across many industries to inspect materials and components during production and in-service for flaws and damage without impairing future usefulness or serviceability.
This document provides an introduction to nondestructive testing (NDT) by defining NDT, describing the six most common NDT methods (visual inspection, liquid penetrant testing, magnetic particle testing, ultrasonic testing, eddy current testing, and radiography), and giving examples of common NDT applications in various industries. NDT allows inspection or measurement of materials, components, and structures without causing damage and is used across industries for applications like flaw detection, leak detection, and dimensional measurements.
This document provides an introduction to nondestructive testing (NDT) by defining NDT, describing the six most common NDT methods (visual inspection, liquid penetrant testing, magnetic particle testing, ultrasonic testing, eddy current testing, and radiography), and giving examples of common NDT applications in various industries. NDT allows inspection or measurement of materials, components, and structures without causing damage and is used across industries for applications like flaw detection, leak detection, and dimensional measurements.
This document discusses non-destructive testing (NDT) methods. It begins by defining NDT as techniques used to evaluate materials without causing damage. It then lists common NDT types like visual inspection, liquid penetrant, ultrasonic, and radiographic testing. For each type, it provides a brief overview of the principles and applications. The document focuses on liquid penetrant testing, describing the procedure and noting it is useful for inspecting parts like aircraft wheels and automotive pistons. It also discusses advantages of NDT like avoiding failures and ensuring safety. In conclusion, it states that NDT can save costs for facilities that implement its methods properly.
This document provides an overview of non-destructive testing (NDT) methods. It describes six common NDT methods - visual inspection, liquid penetrant inspection, magnetic particle inspection, radiography, eddy current testing, and ultrasonic inspection. For each method it explains the basic principles, advantages, limitations and applications for inspecting materials and detecting flaws without causing damage. NDT methods are used at various stages of production and service to evaluate integrity and detect issues in a wide range of industries.
IRJET-Analysis and Optimization of Cutting Parameters in Turning using Tic -...IRJET Journal
This document analyzes and optimizes cutting parameters in turning chrome-moly alloy steel using TiC-coated carbide inserts. Twenty-seven experiments were conducted using a L27 orthogonal design to evaluate the effects of cutting speed, feed rate, and depth of cut on surface roughness, power consumption, chip reduction coefficient, and tool wear. The results show that feed rate and depth of cut significantly affect surface roughness, while cutting speed, depth of cut, and feed rate influence power consumption and tool wear. Optimizing these cutting parameters can improve the machining performance and surface quality when hard turning chrome-moly alloy steel.
The document discusses serial number restoration. It explains that serial numbers are unique identifiers applied by manufacturers to objects like firearms. Criminals sometimes obliterate serial numbers to avoid identification. Restoration involves polishing the surface and using acid to etch away layers of metal, revealing the original serial number imprint beneath. The restored number is then documented through writing or photos. The process helps identify stolen objects by recovering the obscured identifying marks.
This document provides an overview of non-destructive testing (NDT) methods and their applications. It defines NDT as using noninvasive techniques to inspect materials and structures without causing harm. The five most common NDT methods are outlined as liquid penetrant, magnetic, ultrasonic, eddy current, and radiography. Examples of applications discussed include inspecting raw materials and structures for defects, inspecting aircraft and bridges for cracks or corrosion, and monitoring pipes, tanks, and power plant equipment during operation for damage or wear. Regular inspections using NDT help prevent failures in critical infrastructure and ensure safety.
Non destructive test in concrete in building construction architectureAditya Sanyal
This document discusses non-destructive testing methods for concrete, including rebound hammer testing and ultrasonic pulse velocity testing. It explains that non-destructive testing allows evaluation of concrete properties like strength and homogeneity without damaging the structure. Some benefits are lower cost compared to destructive testing and ability to test both new and existing structures. Common non-destructive tests described include rebound hammer, ultrasonic pulse velocity, permeability, and covermeter tests.
This document discusses various welding defects such as slag inclusion, undercut, porosity, incomplete fusion, overlap, underfill, spatter, excessive convexity, incomplete penetration, and excessive penetration. It provides the causes and ways to prevent or repair each defect. Nondestructive and destructive testing methods for inspecting welds are also summarized, including visual inspection, ultrasonic testing, radiographic testing, dye penetrant testing, magnetic particle testing, and mechanical tests.
This document provides an introduction to nondestructive testing (NDT) methods. It defines NDT as using noninvasive techniques to determine the integrity of a material or structure without causing damage. Six common NDT methods are described: visual inspection, liquid penetrant testing, magnetic particle testing, ultrasonic testing, eddy current testing, and radiography. Examples are given of how NDT is used to inspect aircraft, bridges, pipelines and other structures and components during manufacturing and operation to detect flaws and ensure safety and integrity.
Forensic examination of Blood semen saliva.pptxSuchita Rawat
Forensic serology has evolved significantly since the 19th century. Some key developments include:
- 1863: First presumptive test for blood using hydrogen peroxide discovered.
- 1900: Karl Landsteiner discovers the ABO blood group system, revolutionizing serology.
- 1971: Standard protocols for blood typing established.
- 1957/1965: India's first two Central Forensic Science Laboratories opened in Calcutta and Hyderabad.
- Recent advances include rapid on-site tests, DNA analysis, and immunoassays to identify body fluids like blood, semen, and saliva. These advances have improved the scientific analysis of biological evidence in criminal investigations.
Forensic identification of uncommon body fluids.pptxSuchita Rawat
This document discusses forensic serology and the identification of bodily fluids through presumptive and confirmatory assays. It describes tests to identify urine such as the DMAC assay to detect urea and the Jaffe test to detect creatinine. Confirmatory assays for urine include tests for Tamm-Horsfall glycoprotein and 17-ketosteroids. Methods to identify feces include microscopic examination for undigested matter and tests for urobilinoid pigments. Sweat can be identified using assays for lactate, urea, and amino acids. Tears contain lactoferrin which can be detected via specific test kits. Milk contains nutrients and proteins like lactose and can be tested for lactose
This document compares and contrasts forensic serology techniques for human and animal blood. It discusses:
1. The cellular components of human and most animal blood include red blood cells, white blood cells, and platelets, though some animals have hemocytes instead of platelets.
2. Humans have ABO and Rh blood groups, while animals have different blood groups.
3. Hemoglobin is the main respiratory pigment in humans and other vertebrates, while invertebrates have hemoglobin, haemerythrin, haemocyanin, or chlorocruorin.
4. The colors of human and animal blood can be red, blue, green, or pink.
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.
Sexuality - Issues, Attitude and Behaviour - Applied Social Psychology - Psyc...PsychoTech Services
A proprietary approach developed by bringing together the best of learning theories from Psychology, design principles from the world of visualization, and pedagogical methods from over a decade of training experience, that enables you to: Learn better, faster!
The cost of acquiring information by natural selectionCarl Bergstrom
This is a short talk that I gave at the Banff International Research Station workshop on Modeling and Theory in Population Biology. The idea is to try to understand how the burden of natural selection relates to the amount of information that selection puts into the genome.
It's based on the first part of this research paper:
The cost of information acquisition by natural selection
Ryan Seamus McGee, Olivia Kosterlitz, Artem Kaznatcheev, Benjamin Kerr, Carl T. Bergstrom
bioRxiv 2022.07.02.498577; doi: https://doi.org/10.1101/2022.07.02.498577
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.
(June 12, 2024) Webinar: Development of PET theranostics targeting the molecu...Scintica Instrumentation
Targeting Hsp90 and its pathogen Orthologs with Tethered Inhibitors as a Diagnostic and Therapeutic Strategy for cancer and infectious diseases with Dr. Timothy Haystead.
PPT on Direct Seeded Rice presented at the three-day 'Training and Validation Workshop on Modules of Climate Smart Agriculture (CSA) Technologies in South Asia' workshop on April 22, 2024.
Describing and Interpreting an Immersive Learning Case with the Immersion Cub...Leonel Morgado
Current descriptions of immersive learning cases are often difficult or impossible to compare. This is due to a myriad of different options on what details to include, which aspects are relevant, and on the descriptive approaches employed. Also, these aspects often combine very specific details with more general guidelines or indicate intents and rationales without clarifying their implementation. In this paper we provide a method to describe immersive learning cases that is structured to enable comparisons, yet flexible enough to allow researchers and practitioners to decide which aspects to include. This method leverages a taxonomy that classifies educational aspects at three levels (uses, practices, and strategies) and then utilizes two frameworks, the Immersive Learning Brain and the Immersion Cube, to enable a structured description and interpretation of immersive learning cases. The method is then demonstrated on a published immersive learning case on training for wind turbine maintenance using virtual reality. Applying the method results in a structured artifact, the Immersive Learning Case Sheet, that tags the case with its proximal uses, practices, and strategies, and refines the free text case description to ensure that matching details are included. This contribution is thus a case description method in support of future comparative research of immersive learning cases. We then discuss how the resulting description and interpretation can be leveraged to change immersion learning cases, by enriching them (considering low-effort changes or additions) or innovating (exploring more challenging avenues of transformation). The method holds significant promise to support better-grounded research in immersive learning.
6. TYPES OF TOOL MARKS
Compression type marks/Indentation marks
Striated marks/Abrasion marks
Cutting marks
Combination of compression and striated marks
9. FORENSIC EXAMINATION
Tool mark examination from Crime Scene
Toolmark Documentation (photography/tracing/lifting
of toolmarks by casting)
Examination of Foreign material
Taking test impression
Comparison of toolmark impression
10. TOOL SURFACE
CHARACTERISTICS
• Tools have unique characteristics
resulting from manufacturing processes
and from use over time.
• Nicks, ridge marks, and blemishes may
develop on the striking surface of the
tool.
• These unique characteristics from
natural wear and tear can affect
impressions made by the tools, making
them unique as well.
• Other factors are oxidation or rusting of
tools and uneven sharpening.
11. TOOL MARK EXAMINATION
All crime-scene investigators
approach an investigation
methodically and carefully.
Tool mark evidence includes
the mark left at the scene as
well as the tool.
The tool may be recovered
from the suspect or may have
been left at the crime scene or
discarded elsewhere. This Photo by Unknown Author is licensed under CC BY-
NC-ND
12. DOCUMENTING THE EVIDENCE
• The best way to document tools and tool mark
evidence is to use photography.
• All evidence is photographed with a measuring
device to show the appropriate scale for
reference.
Photographing Tools
• When photographing a tool, experts focus on
any scratches or gouges on the surface.
• Oblique lighting is preferred to direct lighting
because it casts shadows and highlights details
that are not easily visible under direct lighting.
• Magnesium smoking is often used on dark-
colored tools.
In this method, magnesium ribbon is burned, which
produces a white, powdery film of magnesium
oxide that coats the surface of the tool. Coating the
tool highlights the detail during photography.
13. Photographing Tool Marks
• While photographing and recording the tool mark evidence, the expert searches
the surface of the tool mark for bits of foreign material using oblique lighting.
Example : If the surface is painted, the expert records if any paint was chipped
away and provides a description.
Tracing
Tool marks can be traced on a tracing paper. This helps in comparing the class
characteristics.
This Photo by Unknown Author is licensed under CC
BY-NC-ND
14. CASTING IMPRESSIONS
The crime scene investigator may actually
cut a part from the door or door jamb
that contains tool mark evidence.
If this is not possible, casting is a
commonly used method of preserving
impressions of the tool marks.
The cast impression will retain the unique
indentation marks made by a specific tool.
Plastic/rubber, plaster of Paris, dental
cast, metal casting, cellulose acetate
dusted for fingerprints (magnetic
dusting powder and silicone material )
the size of the impression
This Photo by Unknown Author is licensed under CC BY-
SA
15. Taking test impression
The material for test impression must be soft
soft enough so that the tool edge will not be
altered (modeling wax )
When the original mark is in wood, paint or
soft metal, hard metal such as steel or brass
the standard should be made with a similar
material.
In cases involving wire cutters the test tool
marks can be cable made from copper or
aluminum.
Several test impressions should be made at
various angles with the tool.
17. Comparison of tool marks
A tool mark must be compared with tool mark, mould with mould and photograph wit
photograph having same magnification.
The comparison is best done by using comparison microscope and with oblique
illumination.
Magnification of test and crime sample should be identical.
This Photo by Unknown Author is licensed under CC BY
18. Source: RG Nichols 2000
Source: RG Nichols 2000
Comparison of tool marks
19. Source: RG Nichols 2000
Source: RG Nichols 2000
Comparison of tool marks
21. F O RENSIC S CI ENCE UG
S E M ESTER V
FORENSIC PHYSICS AND
BALLISTICS
22. This Photo by Unknown Author is licensed under CC BY-SA
23. COLLECTING AND PRESERVING
A SAMPLE
• All evidence is carefully transported to the forensic laboratory to protect it
from damage.
• When tools are found, they are collected and packaged separately in
containers or boxes and then taken to a laboratory for analysis.
• The object containing the tool mark or the actual impression cast is also
packaged in a container or box and taken to the laboratory.
• Small objects may be wrapped with clean paper and placed in small
containers or plastic bags, while larger objects can be packed in cartons or
boxes.
• All evidence must also be correctly labelled and processed.
24. Photo 1-2 Pipe with tool marks. The spacing between tool
marks on the pipe is 4 mm apart.
Case 1 - Pipe and Vise
Grip Arson
Investigation
Evidence Submitted:
Evidence collected at
the scene of a possible
arson investigation.
One vise grip
Request: Could the vise
grip obtained from the
suspect’s auto been
recently used to loosen
the two
sections of gas pipe
found at the scene of a
suspected arson?
26. Case 2 – Gas Explosion Homicide Investigation
A landlord had been unsuccessfully trying to evict an old woman from her rent
controlled apart for years. A gas explosion occurred at the location and the old woman
was killed. The arson investigator suspected foul play, obtained two search warrants,
and searches the building’s basement and the landlord’s home.
Evidence Submitted: Two sections of gas pipes (building’s basement where the
explosion ) and (landlord’s basement)of gas pipes with apparent tool marks .
Request: Determine if the tool marks on the known gas pipe (K-2a) were consistent
with the tool marks present on the questioned gas pipe (Q-1a).
27. Photo 5-1 Two gas pipes, one (Q-1a) from the scene of a homicide and gas explosion investigation,
and one gas pipe with known tool marks made with a wrench from the landlord’s basement (pipe
marked K-2a).
28. Photo:
Comparison microscope
photomicrograph showing
one tooth mark on the K-2a
pipe overlapped with
one tooth mark on the Q-1a
pipe (accidental striation)
Photo :
comparison of the
linear and angular
dimensions
(Steriomicrope
Observations)
29. This Photo by Unknown Author is licensed under CC BY-SA
Editor's Notes
A tool is defined as an instrument that is designed to gain a mechanical advantage. It is also commonly thought of as being the harder of two objects that, when brought into forcible contact, will produce a mark on the softer object.
Toolmark is Defined as a mark produced by a tool when that tool is brought into forcible contact with a surface against which the harder tool is used.
Class characteristics: Measurable features of a tool that indicate a restricted group source. They are design features of a tool and are therefore determined before manufacture. Such features include size, the profile of the tool, the type of mark to be expected using the tool, and, sometimes, the direction of travel. Specific examples of class characteristics include the width of a screwdriver blade, the jaw width along with the number and spacing of serrated teeth on the jaws of a pipe wrench, and whether a cut is produced by two blades passing over each other such as the case with scissors or two blades cutting and pinching an object such as when bolt cutters are used.
Individual characteristics Those features are produced by the random imperfections and irregularities of tool surfaces against an object. These imperfections and irregularities are produced incidental to manufacture and are not intended by the manufacturer. They can be microscopic or large, such as when a portion of the tool surface breaks.