scholarly journals Simple Instrumental and Visual Tests for Nonlaboratory Environmental Control

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
L. P. Eksperiandova ◽  
S. V. Khimchenko ◽  
N. A. Stepanenko ◽  
I. B. Shcherbakov
Keyword(s):  
Polyethylene Terephthalate ◽  
Polyurethane Foam ◽  
Environmental Control ◽  
Kinetic Method ◽  
Colorimetric Method ◽  
Trace Impurities ◽  
Fast Analysis ◽  
Digital Devices ◽  
Express Analysis ◽  
Colored Complexes

Proposed are simple and available techniques that can be used for rapid and reliable environmental control specifically of natural water by means of instrumental and visual tests in outdoor conditions. Developed are the chemical colorimetric modes for fast detection of socially dangerous trace impurities in water such as Co(II), Pd(II), and Rh(III) as well asNO2--ions and Fe(III) serving as model impurities. Application of portable digital devices and scanner allows estimating the color coordinates and increasing the accuracy and sensitivity of the tests. The combination of complex formation with preconcentration of colored complexes replaces the sensitive but time-consuming and capricious kinetic method that is usually used for this purpose at the more convenient and reliable colorimetric method. As the test tools, the following ones are worked out: polyurethane foam tablets with sorbed colored complexes, the two-layer paper sandwich packaged in slide adapter and saturated by reagents, and polyethylene terephthalate blister with dried reagents. Fast analysis of polyurethane foam tablets is realized using a pocket digitalRGB-colorimeter or portable photometer. Express analysis of two-layer paper sandwich or polyethylene terephthalate blister is realized by visual and instrumental tests. The metrological characteristics of the developed visual and instrumental express analysis techniques are estimated.

scholarly journals Evaluation And Selection Of Colour Spaces For Digital Systems

2020 ◽  
pp. 86-94
Author(s):  
Vera L. Zhbanova
Keyword(s):  
Spectral Characteristics ◽  
Colorimetric Method ◽  
Digital Systems ◽  
Colour Difference ◽  
Colour Space ◽  
Digital Devices ◽  
Initial Stage ◽  
Photo Detectors ◽  
The Difference ◽  
Selection Of

The research examined the changing of colour difference by the control colours depending on the choice of colour space when working with matrix photo detector. The spectral characteristics of photo detectors from different manufacturers noticeably differ from each other and from the addition the difference in colour quality between different digital devices. A software method for studying the colour rendition of the image obtained by digital devices based on the selection of an individual colour space for each matrix photo detector is proposed. To analyze and evaluate the capabilities of the spectral characteristics of matrix photo detectors, the control colour method based on the Mansell Atlas was used. The analysis of the obtained parameters of 14 colours was carried out according to various criteria for seven colour spaces: sRGB, AdobeRGB, DCI-P3 RGB, M1N1P1, PAL / SECAM, Wide Gamut RGB, ProPhoto RGB. Also studied the influence of the choice of colour space on the change in the coordinates of the source 6,500 K. Based on the colour differences of the control colours, it is possible to choose the optimal colour space for working with a specific matrix photo detector. The latter will reduce colour distortion at the initial stage of image registration. The ways for improving the colorimetric method of control colours are proposed as applied to digital devices at the software level.

Polyethylene Terephthalate/Carbon Fabric/Polyurethane Foam Sandwich Composites: Flame Retardance and Mechanical Properties

2019 ◽  
Vol 20 (6) ◽  
pp. 1277-1283
Author(s):  
Liwei Wu ◽  
Jingyan Ban ◽  
Qian Jiang ◽  
Ting-Ting Li ◽  
Bing-Chiuan Shiu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Polyethylene Terephthalate ◽  
Polyurethane Foam ◽  
Flame Retardance ◽  
Sandwich Composites ◽  
Carbon Fabric

Automated discrete kinetic method for erythrocyte acetylcholinesterase and plasma cholinesterase.

1981 ◽  
Vol 27 (6) ◽  
pp. 926-929 ◽  
Author(s):  
P J Lewis ◽  
R K Lowing ◽  
D Gompertz
Keyword(s):  
Cholinesterase Activity ◽  
Kinetic Method ◽  
Colorimetric Method ◽  
Acetylcholinesterase Activity ◽  
Plasma Cholinesterase ◽  
Organophosphate Pesticides ◽  
Plasma Cholinesterase Activity ◽  
Quinidine Sulfate

Abstract We describe an automated kinetic method for erythrocyte acetylcholinesterase (EC 3.1.1.7) and plasma cholinesterase (EC 3.1.1.8) based on Ellman's colorimetric method. Quinidine sulfate is used as an inhibitor of plasma cholinesterase during the measurement of erythrocyte acetylcholinesterase activity, obviating the need for washing the erythrocytes before lysis. Results by this method are compared with those obtained by the electrometric delta pH method of Michel. To emphasize the need for measuring both erythrocyte acetylcholinesterase and plasma cholinesterase activity in workers exposed to organophosphate pesticides, we present a study of serial activities of both enzymes in a person accidentally exposed to demeton-S-methyl.

scholarly journals Antibacterial Filtration Using Polyethylene Terephthalate Filters Coated with Copper Nanoparticles

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Vinh Tien Nguyen ◽  
Quang Hoang Anh Vu ◽  
Thi Ngoc Nhi Pham ◽  
Khanh Son Trinh
Keyword(s):  
Escherichia Coli ◽  
Polyethylene Terephthalate ◽  
Copper Nanoparticles ◽  
Colorimetric Method ◽  
Sodium Hypophosphite ◽  
Bacterial Cells ◽  
Sem Images ◽  
Point Of Use ◽  
Icp Ms ◽  
The One

The purpose of this study is to produce antibacterial filters based on a commercial polyethylene terephthalate (PET) filter with pores larger than bacterial cells. The antibacterial agent was copper nanoparticles (CuNP) which were synthesized and deposited on the PET filter by reducing copper(II) ions using sodium hypophosphite (NaH2PO2) as the reducing agent and polyvinylpyrrolidone (PVP) as the capping agent. Scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy confirmed the presence of 150–300 nm CuNP on the surface of PET filters. We evaluated the amounts of deposited CuNP using a colorimetric method and the antibacterial-filtration capacity of CuNP/PET filters against Escherichia coli using the colony counting method. The reaction conditions were optimized successively using the one-factor-at-a-time approach for the concentration of copper precursor, the concentration of PVP, and the reaction time. The results showed that an initial 1 M CuSO4, 0.8% w / v PVP, and 10-20 min of reaction resulted in a CuNP/PET filter with the highest antibacterial activity: 5.2 log cfu/mL reduction for Escherichia coli and 5.6 log cfu/mL reduction or Staphylococcus aureus. SEM images demonstrated the damages of the bacterial cells after passing through the CuNP/PET filter. ICP-MS analysis of the first liter of filtrate showed that the copper concentration of released copper was 0.6 ± 0.1  ppm, which is below the WHO standard for drinking water. Therefore, these CuNP/PET filters are promising for point-of-use disinfection of water, where clean potable water is not sufficient.

scholarly journals Preliminary Evaluation of Gunshot Residue (GSR) Using 3-Aminophenol as a Substitute in Modified Griess Test

2021 ◽  
Vol 21 (6) ◽  
pp. 1550
Author(s):  
Siti Nurhazlin Jaluddin ◽  
Zainiharyati Mohd Zain ◽  
Mohamed Izzharif Abdul Halim ◽  
Muhd Fauzi Safian ◽  
Mohd Azri Abdul Rani ◽  
...  
Keyword(s):  
Colorimetric Method ◽  
Sulfanilic Acid ◽  
Gunshot Residue ◽  
Rapid Screening ◽  
Screening Methods ◽  
Preliminary Evaluation ◽  
Fast Analysis ◽  
Color Changes ◽  
Rapid Screening Test ◽  
Griess Test

In forensic ballistics, gunshot residue (GSR) particles can be detected using screening or presumptive tests which are mainly focused on the chromophoric reaction. Most tests serve as an initial indication for a forensic investigator at the crime scene before instrumental analysis for definitive identification. The screening methods are known to be convenient, have fast analysis, and minimal preparation. In GSR analysis, the well-known method of detecting GSR known as the Modified Griess Test (MGT) requires acid and heat for the reaction. Therefore, this study demonstrated a new and rapid screening test named the Rapid Griess Test (RGT) for the detection of GSR. This study intends to improve the functionality of previous screening reagents in determining nitrite (NO2–), the composition present after shooting activity. To do this, chemical reagents with an amino group, 3-aminophenol, were substituted with alpha-naphthol. The experiment showed that the reactions were positive color changes using standard NO2– and real GSR samples. The diazotization reactions involving sulfanilic acid and 3-aminophenol produced azo dyes that changed the solution from colorless to orange in the presence of NO2–. The RGT reagent will make it possible to avoid using heat and the addition of acetic acids in a sample to form chromophoric reactions. Moreover, the colorimetric method using Video Spectral Comparator (VSC) showed that RGT had higher intensity of the orange color when compared to MGT.

scholarly journals Comparison and Optimization of Quantification Methods for Shigella flexneri Serotype 6 O-antigen Containing Galacturonic Acid and Methyl-Pentose

2021 ◽  
Vol 22 (22) ◽  
pp. 12160
Author(s):  
Maria Michelina Raso ◽  
Oscar Vassallo ◽  
Francesca Micoli ◽  
Carlo Giannelli
Keyword(s):  
Galacturonic Acid ◽  
Vaccine Development ◽  
Shigella Flexneri ◽  
Colorimetric Method ◽  
Original Method ◽  
Fast Analysis ◽  
Middle Income ◽  
Middle Income Countries ◽  
O Antigen

Shigella is a leading diarrheal cause of morbidity and mortality worldwide, especially in low- and middle-income countries and in children under five years of age. Increasing levels of antimicrobial resistance make vaccine development an even higher global health priority. S. flexneri serotype 6 is one of the targets of many multicomponent vaccines in development to ensure broad protection against Shigella. The O-antigen (OAg) is a key active ingredient and its content is a critical quality attribute for vaccine release in order to monitor their stability and to ensure appropriate immune response. Here, the optimization of two methods to quantify S. flexneri 6 OAg is reported together with the characterization of their performances. The optimized Dische colorimetric method allows a tenfold increment of the sensitivity with respect to the original method and is useful for fast analysis detecting selectively methyl-pentoses, as rhamnose in S. flexneri 6 OAg. Also, a more specific HPAEC-PAD method was developed, detecting the dimer galacturonic acid-galactosamine (GalA-GalN) coming from S. flexneri 6 OAg acid hydrolysis. These methods will facilitate characterization of S. flexneri 6 OAg based vaccines. The colorimetric method can be used for quantification of other polysaccharide containing methyl-pentoses, and the HPAEC-PAD could be extended to other polysaccharides containing uronic acids.

Thermal Considerations in Lens Regulator Systems

1970 ◽  
Vol 28 ◽  
pp. 358-359
Author(s):  
K.C. Newton
Keyword(s):  
Electron Microscope ◽  
Thermal Effects ◽  
Environmental Control ◽  
Reference Networks ◽  
Better Than

Thermal effects in lens regulator systems have become a major problem with the extension of electron microscope resolution capabilities below 5 Angstrom units. Larger columns with immersion lenses and increased accelerating potentials have made solutions more difficult by increasing the power being handled. Environmental control, component choice, and wiring design provide answers, however. Figure 1 indicates with broken lines where thermal problems develop in regulator systemsExtensive environmental control is required in the sampling and reference networks. In each case, stability better than I ppm/min. is required. Components with thermal coefficients satisfactory for these applications without environmental control are either not available or priced prohibitively.

Atomic force microscopy (AFM) of the topography of silicon surfaces exposed to ion beams

1992 ◽  
Vol 50 (2) ◽  
pp. 1132-1133
Author(s):  
Mark Denker ◽  
Jennifer Wall ◽  
Mark Ray ◽  
Richard Linton
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Incidence Angle ◽  
Ion Beam ◽  
Depth Profiling ◽  
Depth Resolution ◽  
Ion Beams ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Trace Impurities ◽  
Energy Dose

Reactive ion beams such as O2+ and Cs+ are used in Secondary Ion Mass Spectrometry (SIMS) to analyze solids for trace impurities. Primary beam properties such as energy, dose, and incidence angle can be systematically varied to optimize depth resolution versus sensitivity tradeoffs for a given SIMS depth profiling application. However, it is generally observed that the sputtering process causes surface roughening, typically represented by nanometer-sized features such as cones, pits, pyramids, and ripples. A roughened surface will degrade the depth resolution of the SIMS data. The purpose of this study is to examine the relationship of the roughness of the surface to the primary ion beam energy, dose, and incidence angle. AFM offers the ability to quantitatively probe this surface roughness. For the initial investigations, the sample chosen was <100> silicon, and the ion beam was O2+.Work to date by other researchers typically employed Scanning Tunneling Microscopy (STM) to probe the surface topography.

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