Nitrogen dioxide gas-sensing properties of hydrothermally synthesized WO3 · nH2O nanostructures

Nitrogen dioxide (NO2) has been identified as a serious air pollutant that threats to our environment, human life and world ecosystems. Therefore, detection of this air pollutant is crucial. Metal oxide semiconductor is one of the best approaches frequently used to detect NO2 at relatively low temperatures. Hydrated tungsten trioxide (WO3 · H2O), an n-type semiconductor, is regarded to be a promising material for fabricating gas sensors, which are widely used in environmental and safety monitoring. In this work, WO3 · nH2O nanoparticles have been synthesized using a polyfunctional surfactant-mediated hydrothermal approach in the addition of H2C2O4 and K2SO4 at a molar ratio of 1 : 1. This paper has also reported the effect of reaction temperature (120°C to 200°C) on morphological changes and gas-sensing performance. The characterization of these synthesized nanostructures was carried out by UV–Vis absorption spectroscopy, X-ray diffraction and field-emission scanning electron microscopy (FESEM). The UV absorption peak was obtained around 300 nm. FESEM analysis showed sheet-like structures come together to form flower-type morphology. The synthesized WO3 · nH2O flower-like structures was then used for NO2 gas-sensing application. The prepared sensors showed considerably better sensor response (Rg/Ra = 17.48) at 185°C for 25 ppm NO2

Recent progress in electrochemical detection of gluthathoine: A review

Glutathione is a naturally occurring tripeptide that is involved in bio-reductive processes, enzyme activity, amino acid transport, DNA synthesis, detoxification metabolism, oxidative stress protection, and cell defense. However due to low GSH levels less than 0.5 ​μM, various major human disorders occurred such as asthma, cancer, hepatitis, liver disease, HIV, and chlamydia etc. GSH levels can be detected using a variety of analytical techniques. However, these techniques are costly, time consuming and complex. Hence, to overcome these issues, designing and manufacturing of inexpensive, sensitive, and fast response sensors is needed for GSH detection. Using various methodologies, different mechanisms for determining glutathione have been proposed for GSH sensors. Amongst all electrochemical GSH sensors have shown a key role in obtaining reliable and sensitive detection. Electrochemical detection of glutathione (GSH) has gained significant attention in recent years due to its potential in various fields such as biomedical research, clinical diagnostics, environmental monitoring, and food safety. The electrochemical sensing of GSH has several technological advantages, including high sensitivity, selectivity, miniaturization, and point-of-care (POC) detection capabilities. The applicability of current GSH sensors is increased by the vast range of electrode approaches, performance characteristics and electrochemical techniques described in this review. This review focuses on the electrochemical detection of GSH using various electrodes such as carbon-based electrodes and ITO based electrodes

Study on the formulation of green/eco thick film piezo resistive paste for strain gauge application

Thick film piezo resistors, such as strain gauges fabricated using screen printing technology, are widely used for pressure-sensing applications. This paper reports the study of RuO2-based piezoresistive pastes formulation using lead-free glass frits for their potential application for strain gauges. Thermal analysis (TG/DTA) of the prepared glass frit and piezo resistor paste composition was performed to understand the thermal behavior of the paste and the glass transition temperature of the glass frit. The XRD patterns of the films revealed no variation in the conductive phase concentration concerning the firing temperature. SEM analysis of the glass frit powders and the RuO2 powder show submicron-sized agglomerated particles. Electrical measurements showed that the samples fired at 750 ​°C have high gauge factor values (GFL ​= ​18.08, GFT= 12.50), indicating that this is the most suitable firing temperature to achieve the high gauge factor in the present study

Purification and characterization of lipase from Acinetobacter haemolyticus TA 106 isolated from human skin

Acinetobacter sp. isolated from healthy human skin of a tribal population was tested for lipase production.Medium optimization was achieved to increase the production. Purification was carried out by a one-step purification process using DEAE Sephadex A-50. The molecular weight of the lipase was approximately 60 kDa by SDS-PAGE. The purified lipase showed not only good stability in the presence of detergents and organic solvents but also an enhancement of activity. The lipase was active at pH 9 and displayed good activity at 0, 30 and 37°C. It was inhibited in EDTA, suggesting that it is a metalloenzyme. The cations like Ca2+, Mg2+, and Cu2+ significantly reduced the lipase activity at 5 mM concentration. The lipase converted 67% oleic acid to methyl oleate at 37°C at 72 h. All these features make this lipase an important candidate from an industrial point of view

Production of bioemulsifier by <i style="">Acinetobacter</i> species isolated from healthy human skin

70-76Six Acinetobacter sp. isolated from healthy human skin were checked for the production of bioemulsifier. Optimization studies indicated that Luria Bertani broth pH 7 supplemented with calcium chloride (1%) was the optimum medium. Temperature at 37°C was optimum and inducer oils in the medium did not enhance bioemulsifier production. Partial purification of bioemulsifier and chemical analysis revealed that it is a proteoglycan with protein (53%), polysaccharide (43%) and lipid (2%). Maximum emulsification activity obtained was 400 EU/ml. Thin layer chromatography revealed the presence of mannose and rhamnose sugar and oleic and palmitic acids as parts of lipids. The yield obtained was 1.9 g / l. Reconstitution studies revealed that the protein and polysaccharide fractions together display 94.55% of emulsification activity. It was also noted that the bioemulsifier was stable for 72 hr at 37°C and displayed good cleaning property towards different oils. The partially purified bioemulsifier formed stable oil-in-water emulsions with plant oils

Evaluation of soybean peroxidase - Copper phosphate mediated organic-inorganic hybrid for hydrogen peroxide biosensor application

An electrochemical biosensor for H2O2 detection was developed by using soybean peroxidase-copper phosphate mediated organic inorganic hybrid (OIH). The characterization of OIH was carried out by FESEM and FTIR. FESEM analysis showed a flower-like porous morphology of the OIH and FTIR confirmed the presence of soybean peroxidase and copper phosphate in the OIH. For sensor development, the paste of OIH was formulated in the presence of phosphate buffered saline (PBS) and was screen printed on indium tin oxide (ITO) coated glass substrate. Cyclic voltammetry analysis showed that the developed biosensor could detect H2O2 in the linear range of 20–100 ​μM with R2 value of 0.963. The limit of detection (LOD) and sensitivity values calculated for H2O2 are 0.19 ​μM and 27.44 μA/(μM.cm2) respectively. Along with cyclic voltammetry experiments, electrochemical impedance spectroscopy (EIS) analysis was also carried out to study the sensing mechanism. The developed biosensor showed better selectivity towards H2O2 when tested against d-glucose, l-tyrosine, l-lysine, and l-ascorbic acid

Text Character Extraction Implementation from Captured Handwritten Image to Text Conversionusing Template Matching Technique

Images contain various types of useful information that should be extracted whenever required. A various algorithms and methods are proposed to extract text from the given image, and by using that user will be able to access the text from any image. Variations in text may occur because of differences in size, style,orientation, alignment of text, and low image contrast, composite backgrounds make the problem during extraction of text. If we develop an application that extracts and recognizes those texts accurately in real time, then it can be applied to many important applications like document analysis, vehicle license plate extraction, text- based image indexing, etc and many applications have become realities in recent years. To overcome the above problems we develop such application that will convert the image into text by using algorithms, such as bounding box, HSV model, blob analysis,template matching, template generation

Text Character Extraction Implementation from Captured Handwritten Image to Text Conversionusing Template Matching Technique

Images contain various types of useful information that should be extracted whenever required. A various algorithms and methods are proposed to extract text from the given image, and by using that user will be able to access the text from any image. Variations in text may occur because of differences in size, style,orientation, alignment of text, and low image contrast, composite backgrounds make the problem during extraction of text. If we develop an application that extracts and recognizes those texts accurately in real time, then it can be applied to many important applications like document analysis, vehicle license plate extraction, text- based image indexing, etc and many applications have become realities in recent years. To overcome the above problems we develop such application that will convert the image into text by using algorithms, such as bounding box, HSV model, blob analysis,template matching, template generation