scholarly journals Restoration of Obliterated Stamped Marks on Aluminium Surfaces by Metallographic Etching Technique

2020 ◽  
Vol 36 (6) ◽  
pp. 1212-1217
Author(s):  
Amit Kumar ◽  
Ankit Srivastava ◽  
Tanurup Das ◽  
Abhimanyu Harshey ◽  
Veer Raj Saini ◽  
...  
Keyword(s):  
Forensic Science ◽  
Ferric Chloride ◽  
Present Experiment ◽  
Chemical Etching ◽  
Simple Technique ◽  
Distilled Water ◽  
Metallic Surfaces ◽  
Etching Technique ◽  
Restoration Process ◽  
Science Laboratories

Serial number restoration is a frequently encountered problem in forensic science laboratories for the investigation of theft and burglary cases. These identification marks are generally introduced over metallic surfaces of different vehicle parts and firearms by various means. Chemical etching is one of the most effective and simple technique to restore obliterated, erased, over-stamped and over-engraved marks on metallic surfaces. Several significant studies on restoration of engraved markings on aluminium surfaces were previously reported. The present study attempts to find out an efficient and fast etching reagent to restore obliterated stamped marks on aluminium surfaces. Ten effective etching reagents previously reported by various researchers in their restoration studies were assessed in the present experiment. Etching reagents were individually applied on obliterated surfaces by the cotton swabbing method. The Reagent 3 (ferric chloride 25 g, conc. HCl 25 mL, distilled water 100 mL) was found out to be the most sensitive and rapid (4–6 min) for the restoration on aluminium surfaces. The study also revealed that the absence of an alkaline compound in etching reagent potentially accelerates the speed of the restoration process.

Controllable end shape modification of ZnO nano-arrays/rods by a simple wet chemical etching technique

2015 ◽  
Vol 48 (36) ◽  
pp. 365303 ◽  
Author(s):  
Jingchang Sun ◽  
Ting Zhao ◽  
Zhangwei Ma ◽  
Ming Li ◽  
Cheng Chang ◽  
...  
Keyword(s):  
Chemical Etching ◽  
Shape Modification ◽  
Etching Technique ◽  
Wet Chemical ◽  
Wet Chemical Etching

scholarly journals The Art of Tungsten Etching in Semiconductor Chips

1999 ◽  
Vol 7 (2) ◽  
pp. 24-25
Author(s):  
Lisa Litz-Montanaro
Keyword(s):  
Manufacturing Process ◽  
Chemical Etching ◽  
Layer By Layer ◽  
Ion Milling ◽  
Etching Technique ◽  
Semiconductor Structures ◽  
Wet Chemical ◽  
Wet Chemical Etching ◽  
Semiconductor Chips ◽  
Complex Semiconductor

In the course of both physical and failure analysis of semiconductor chips (i.e., verifying what you actually deposited as a layer, vs, what caused the circuit to fail), it is essential to have appropriate deprocessing tools at your disposal in order to evaluate complex semiconductor structures, Deprocessing techniques are developed for each product manufactured and involve multi-step procedures that reveal the layer-by-layer secrets of the chip, These techniques require constant tweaking in duration and procedure as the manufacturing process imposes changes and as the architecture of the semiconductor changes. While there are many tools that assist in these analytical pursuits, such as RIE (reactive ion etching - a dry etching technique), ion milling, and microcleaving, the wet chemical etching of tungsten is sometimes more reproducible than RIE techniques.

Practice of offender profiling in Japan

2017 ◽  
Vol 19 (3) ◽  
pp. 187-194 ◽  
Author(s):  
Kaeko Yokota ◽  
Hiroki Kuraishi ◽  
Taeko Wachi ◽  
Yusuke Otsuka ◽  
Kazuki Hirama ◽  
...  
Keyword(s):  
Forensic Science ◽  
National Survey ◽  
Prediction Accuracy ◽  
Current Situation ◽  
Demographic Characteristics ◽  
Statistical Analyses ◽  
Offender Profiling ◽  
Police Investigations ◽  
Science Laboratories ◽  
Crime Linkage

The main aim of this study was to determine the current situation of offender profiling in Japan. In addition, the accuracy of crime linkage and inferring offenders’ profiles were examined. To evaluate offender profiling comprehensively, we conducted a national survey of 156 people responsible for offender profiling between 2011 and 2012 to obtain their demographic characteristics and experience related to profiling. Furthermore, we also used a sample of 296 resolved cases to examine the content of profiling and the accuracy of predictions in offender profiling. The results of the statistical analyses revealed that police professionals from various backgrounds were engaged in profiling in Japan; 76% were police investigators, and 19% were professionals at forensic science laboratories engaged in psychological work. Regarding the utilization of profiling results in police investigations, 46% of profiling ‘led to identification of offender’. As for prediction accuracy, the rate of linkage errors (i.e. where profilers could not correctly link incidents even when they knew of the occurrence of these incidents) was 15%. Accurately inferring an offender’s profile was found to be between 72% (means of transportation) and 100% (sex). We also discussed the challenges faced by the police who practise offender profiling in Japan.

Medical Technologists in Forensic Science Laboratories in the United States

1991 ◽  
Vol 22 (1) ◽  
pp. 40-44
Author(s):  
Richard O. Pfau ◽  
John R. Snyder ◽  
Sally V. Rudmann ◽  
Joseph E. Scott
Keyword(s):  
United States ◽  
Forensic Science ◽  
The United States ◽  
Science Laboratories ◽  
Medical Technologists

scholarly journals The Estimation of Zinc in Sea Water using Sodium Diethyldithiocarbamate

1936 ◽  
Vol 20 (3) ◽  
pp. 625-625 ◽  
Author(s):  
W. R. G. Atkins
Keyword(s):  
Fresh Water ◽  
Sea Water ◽  
Sodium Diethyldithiocarbamate ◽  
Distilled Water ◽  
English Channel ◽  
Metallic Surfaces ◽  
The Earth

Sea water contains very little zinc. Values from 0–73 mg. per cubic metre have been cited in Physics of the Earth, V, 180, Washington, 1932. According to Orton it is less than 0–1 parts per million in the English Channel. Dieulafait found 2 nig. and Bodansky 7–3, erroneously quoted as 73 above. The method described here permits of the detection of as little as 8 mg. per m3 using 200 ml. of distilled water in a Hehner tube, the delicacy of the reaction being much greater than that of any other for zinc. Sea water from the English Channel gives no turbidity and so is unlikely to contain as much as 8 mg. per m3. The method is brought forward on account of its usefulness in detecting and estimating zinc in sea water contaminated by contact with metallic surfaces. Its use in fresh water has already been described (Analyst, 1935, 60, p. 400, No. 711, June), and to this paper reference may be made for some possible sources of interference and for the origin of the reagent.

Effect of Dynamic Chemical Etching on the Pore Structure, Permeability, and Mechanical Properties of Ti-Nb-Zr Scaffolds for Medical Applications

2020 ◽  
Vol 143 (5) ◽  
Author(s):  
V. Sheremetyev ◽  
S. Dubinskiy ◽  
M. A. Iqbal ◽  
K. Lukashevich ◽  
S. Prokoshkin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Porous Structure ◽  
Chemical Etching ◽  
Etching Technique ◽  
Essential Step ◽  
Compressive Stresses ◽  
Structure Geometry ◽  
Structure Lead ◽  
New Generation ◽  
Potential Use

Abstract Improving the post-processing of metallic porous tissue scaffolds is an essential step to create a new generation of superelastic implants for the replacement of damaged bone tissue. In this study, the dynamic chemical etching technique is applied to improve the permeability and to optimize the porous structure of Ti-Nb-Zr scaffolds fabricated by the powder metallurgy-based space holder technique. The etched scaffolds are characterized in terms of their porous structure geometry, permeability, and mechanical properties. It is shown that an increase in porosity from 49% to 54% during the etching is mainly due to an increase in the number of 100 to 800 μm-diameter pores, from 30% to 50% of them measuring from 100 to 300 μm in size. These changes in the porous structure lead to a significant increase of its permeability, i.e., from (0.1–15) × 10−11 m2 before etching to (44–91) × 10−11 m2, after etching; these permeability ranges corresponding to those of bone tissues. Furthermore, the etched scaffolds show systematically higher yield compressive stresses as compared to the as-sintered scaffolds of equivalent porosities. Finally, the highly permeable etched Ti-Nb-Zr scaffolds with a porosity varying from 40% to 60% exhibit an apparent Young’s modulus ranging from 8.6 to 1.9 GPa and an ultimate compressive strength from 650 to 190 MPa, which can be considered as a promising balance of properties for the potential use of these scaffolds as bone implants.

scholarly journals World List of Forensic Science Laboratories

Nature ◽  
1963 ◽  
Vol 199 (4891) ◽  
pp. 317-317
Author(s):  
R. A. OUTTERIDGE
Keyword(s):  
Forensic Science ◽  
Science Laboratories ◽  
World List
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