Browsing by Author "Pradeep Kumar Mishra"

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A new insight into the warming potential of organically amended agro-ecosystems
(Springer Netherlands, 2018) Pratap Srivastava; Rishikesh Singh; Sachchidanand Tripathi; Hema Singh; Akhilesh Singh Raghubanshi; Pradeep Kumar Mishra
Organic fertilization enhances the global warming potential of the soil, which is primarily attributed to higher CO2 emission from the soil. However, long-term studies under organic fertilization to observe its impact on soil’s warming potential with respect to CO2 efflux are limited in the dry tropical ecosystem. Therefore, we observed the changes in soil organic matter (C, N), soil CO2 efflux (SCE), soil moisture, microbial biomass C, and dehydrogenase activity in the plots under 1, 3, 5, and 10 years of organic fertilization, designated as OM1, OM3, OM5, and OM10, respectively. Also, a nearby native forest was taken as a standard reference system (NF) in the present study for comparative purpose. We observed that organic fertilization significantly (P ≤ 0.05) increased soil organic carbon (SOC), soil organic nitrogen (SON), SCE, moisture, microbial biomass C, and dehydrogenase activity, whereas decreased the SOC/SON ratio after 10 years, which also approached closer to NF. However, only the plots under 10 years of organic fertilization showed SCE significantly (P ≤ 0.05) similar to NF. It indicates that long-term organic fertilization is required for the improvement in soil properties. SCE showed a significantly (P ≤ 0.05) higher value (on average, by 61%) in OM10 site as compared to OM1. However, SCE on unit C basis (SCER) showed no change (P > 0.05). This increase in SCE after 10 years of organic fertilization might be attributed to the significant (P ≤ 0.05) increase in SOC, soil moisture, microbial biomass C, and dehydrogenase activity. However, no change in SCER after 10 years shows that organic fertilization has possibly been misinterpreted with respect to their impact on soil’s global warming potential. It might be attributed to the C protective nature of the organic fertilization. Overall, our results contradict with the often publicized higher warming potential of the organically amended systems. This indicates that organic fertilization does not increase the soil’s global warming potential, which is often misrepresented because SCE is not observed with respect to the existing SOC content. © 2017, Springer Science+Business Media B.V.
Assessment of ground and surface water quality along the river Varuna, Varanasi, India
(Kluwer Academic Publishers, 2015) Pardeep Singh; R.K. Chaturvedi; Ankit Mishra; Lata Kumari; Rishikesh Singh; D.B. Pal; Deen Dayal Giri; Nand Lal Singh; Dhanesh Tiwary; Pradeep Kumar Mishra
Multivariate statistical techniques were employed for monitoring of ground-surface water interactions in rivers. The river Varuna is situated in the Indo-Gangetic plain and is a small tributary of river Ganga. The study area was monitored at seven sampling sites for 3 years (2010–12), and eight physio-chemical parameters were taken into account for this study. The data obtained were analysed by multivariate statistical techniques so as to reveal the underlying implicit information regarding proposed interactions for the relevant area. The principal component analysis (PCA) and cluster analysis (CA), and the results of correlations were also studied for all parameters monitored at every site. Methods used in this study are essentially multivariate statistical in nature and facilitate the interpretation of data so as to extract meaningful information from the datasets. The PCA technique was able to compress the data from eight to three parameters and captured about 78.5 % of the total variance by performing varimax rotation over the principal components. The varifactors, as yielded from PCA, were treated by CA which grouped them convincingly into three groups having similar characteristics and source of contamination. Moreover, the loading of variables on significant PCs showed correlations between various ground water and surface water (GW-SW) parameters. The correlation coefficients calculated for various physiochemical parameters for ground and surface water established the correlations between them. Thus, this study presents the utility of multivariate statistical techniques for evaluation of the proposed interactions and effective future monitoring of potential sites. © 2015, Springer International Publishing Switzerland.
Association of mustard oil as cooking media with carcinoma of the gallbladder
(2013) Ruhi Dixit; Piyush Srivastava; Somprakas Basu; Pradeep Srivastava; Pradeep Kumar Mishra; Vijay Kumar Shukla
Purpose Carcinoma of the gallbladder (CaGB) is a common health problem in Northern India. Exact causative factors are still obscure. Dietary habits are also known to be a major factor in the gallbladder carcinogenesis. Mustard oil is mostly used as cooking media, which is adulterated by sanguinarine, diethylnitrosamine and repeated frying. We tried to find out the association of mustard oil as cooking media with CaGB. Methods Twenty patients each of CaGB (group I) and cholelithiasis (group II) were included in the study. Sanguinarine and diethylnitrosamine (DEN) were extracted from the tissue and blood samples from both groups. Mean and standard error of mean of the concentration of the sanguinarine and DEN were calculated. Mann-Whitney U test was applied to test the level of significance between the two groups. Results The mean concentration of tissue sanguinarine in both groups (I and II) was 195.18 ng/mg and 24.05 ng/mg, respectively, and the difference was statistically highly significant (p<0.001). The estimated concentration of blood sanguinarine was 230.96 ng/mL and 14.0 ng/mL in group I and II, respectively, and the difference was statistically highly significant (p<0.001). The concentration of DEN in the tissue sample was 38.08 ng/mg in CaGB and 2.51 ng/mg in cholelithiasis patient, and these values were statistically highly significant (p<0.001). Similarly, blood DEN concentration was 119.05 ng/mL and 4.22 ng/mL in group I and II, respectively, and the difference was statistically highly significant (p<0.001). Conclusion There is an increase in concentration of sanguinarine and diethylnitrosamine in CaGB blood and tissue in comparison to the cholelithiasis group suggesting an association with carcinoma of the gallbladder. © Springer Science+Business Media New York 2012.
Biodegradation of Navy N5RL1 carpet dye by Staphylococcus saprophyticus strain BHUSS X3
(Springer Verlag, 2015) Lata Kumari; Ajay Kumar Verma; Dhanesh Tiwary; Deen Dayal Giri; Gopal Nath; Pradeep Kumar Mishra
Biodegradation of Navy N5RL1, a widely used acidic azo dye in carpet industry, was studied by bacterial strain isolated from the dye-contaminated soil collected from a carpet industry premises located in Bhadohi, Sant Ravidas Nagar and Uttar Pradesh, India. The isolated strain was identified as Staphylococcus saprophyticus BHUSS X3 on the basis of morphological, biochemical and 16S rRNA gene sequencing analysis. The strain BHUSS X3 decolorized 95.7 % of dye (100 mg/l) within 6 h at optimum pH 8, temperature 35 °C, inoculum 4.0 % under static condition during 24 h incubation. The isolated bacterial strain BHUSS X3 can toralate dye concentration upto 1,000 mg/l. The dye degradation metabolites were confirmed by analysis of degraded products using UV–Vis spectrophotometric, HPLC and FTIR technique. The phytotoxicity analysis was also conducted on Phaseolus aureus and enhanced seed germination was recorded. © 2015, The Author(s).
Comparative study of dye degradation using TiO2-activated carbon nanocomposites as catalysts in photocatalytic, sonocatalytic, and photosonocatalytic reactor
(Taylor and Francis Inc., 2016) Pardeep Singh; M.C. Vishnu; Karan Kumar Sharma; Rishikesh Singh; Sughosh Madhav; Dhanesh Tiwary; Pradeep Kumar Mishra
In the present study, activated carbon-based TiO2 nanocomposites with carbon loading were synthesized by sol–gel method for photocatalytic, sonocatalytic, and sonophotocatalytic degradation of colored compound in wastewater. The prepared catalysts were characterized by Brunauer–Emmet–Teller surface area analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared analysis (FT-IR). The degradation efficiencies of the synthesized composites were determined by the degradation of Direct Blue-199 dye under three different reactors viz., photocatalytic, sonocatalytic, and sonophotocatalytic. Reaction kinetic modeling was done for these processes and the degradation rate was found maximum for sonophotocatalytic process as compared to individual ones. However, on considering the energy efficiency and degradation efficiency, photochemical reactor was found to be most economical. Therefore, for the treatment of wastewater-containing dye from industries, a photocatalytic process can be applied with further modification. © 2015 Balaban Desalination Publications. All rights reserved.
Computational study of the performance of a solar dryer for improvement in the shelf life of the food materials
(Springer, 2024) Mukul Sengar; Dhananjay Singh; Pradeep Kumar Mishra; Deepak Singh; Balendu Shekher Giri
In this study, the thermal and drying characteristics of a thin layer food sample were investigated. An indirect type, simple, efficient, and economically feasible solar dryer was fabricated and used for food preservation. However, a dynamic model of a fabricated solar dryer was also presented to gain a better insight into the drying and thermal actions. This model consists of thermal modeling of the drying chamber, solar collector, and solar-dried food sample. The law of conservation of energy was applied to evaluate the temperature at different sections of the solar dryer with respect to drying time. All listed model equations were solved in the MATLAB environment. This study helps to examine the influence of solar radiation on the collector plate temperature, drying chamber temperature, food sample temperature, and performance parameters such as thermal efficiency with respect to drying time. Model data was found in good agreement with experimental data within a 4% error. It is concluded that the drying of food material is affected by air temperature, the collector temperature, mode of heat transfer, and material characteristics such as dimension and mass of the food sample. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.
Current and emerging trends in bioremediation of petrochemical waste: A review
(Taylor and Francis Inc., 2017) Pardeep Singh; Rajat Jain; Neha Srivastava; Anwesha Borthakur; D.B. Pal; Rishikesh Singh; Sughosh Madhav; Pratap Srivastava; Dhanesh Tiwary; Pradeep Kumar Mishra
Various industries release harmful petrochemical contaminants into the environment. To treat these petrochemical contaminants at source, different physical, chemical, and biological methods have been proposed and applied worldwide. However, physical and chemical methods have their own advantages and limitations; in this review, we majorly focused on the biodegradation of petrochemical wastes. First, a background study on the literature available in this field is presented. Second is a review of the toxic effects of petrochemical waste and various physical and chemical processes, followed by elaborate biological processes available for petrochemical waste degradation. Further, different aspects of bioremediation, such as modes, factors, limitations, and future perspectives are critically reviewed and presented. It was found that most of the studies performed on bioremediation of petrochemical waste employed bacteria for the degradation purpose. Some studies also made use of algae, fungi, yeast, genetically modified organisms, biosurfactants, or a consortium of these microbes. Moreover, use of bioremediation is still limited at field scale due to certain limitations, which have been elaborated in this article. Overall, we strongly believe that with bioremediation capturing the attention of environmentalists worldwide, there is still a prevailing need to scale up from lab to land level applications and adaptations. © 2017 Taylor & Francis Group, LLC.
Drying kinetics, thermal and morphological analysis of starchy food material: Experimental investigation through an induced type solar dryer
(Elsevier B.V., 2023) Mukul Sengar; Reeta Rani Singhania; Deepak Singh; Pradeep Kumar Mishra; Dhananjay Singh; Manish Kumar; Balendu Shekher Giri
Solar drying is a green and clean energy-based technique for food preservation. In this study, drying kinetics and thermal, and morphological analyses of food material have been investigated. A mathematical model has also been studied and modified to validate experimental findings. An induced-type solar dryer setup has been fabricated and experiments have been conducted with potatoes as food samples. The weight loss and temperature variations were monitored in all three types of food samples. The average drying efficiency of the dryer has been found as 20.3 %. Scanning electron microscopy analysis has also been done to examine the surface morphology of the solar-dried food samples. The spherical-shaped sample has shown interesting results and they have the quality to attain maximum temperature due to the small surface area among all three shapes. The fabricated experimental setup has an initial cost and better payback period of $ 205.78 and 1.50 yr respectively. © 2023
Effect of nanoscale TiO 2 -activated carbon composite on Solanum lycopersicum (L.) and Vigna radiata (L.) seeds germination
(Joint Center on Global Change and Earth System Science of the University of Maryland and Beijing Normal University, 2016) Pardeep Singh; Rishikesh Singh; Anwesha Borthakur; Pratap Srivastava; Neha Srivastava; Dhanesh Tiwary; Pradeep Kumar Mishra
The extensive use of nanoparticles under different industrial processes and their release into the environment are of major concerns in the present global scenario. In the present study, the effects of activated carbon-based TiO 2 (AC-TiO 2 ) nano-composite on the seed germination of Solanum lycopersicum (tomato) and Vigna radiata (mungbean) were investigated. The size of nanoparticles used in the study ranged from 30 to 50 nm, and their concentrations were from 0 to 500 mg L −1 . The composites were synthesized by sol–gel method and further characterized by scanning electron microscopy, Energy-dispersive X-rays spectroscopy (EDX), Raman spectroscopy, Fourier transform infrared spectroscopy and X-ray diffraction to investigate all the surface structural and chemical properties of AC-TiO 2 nano-composite. The results showed that increase in nano-composite concentration improves the germination rate and reduces germination time up to a certain concentration. Therefore, employing AC-TiO 2 nano-composites in suitable concentration may promote the seed germination and also reduce the germination time in Solanum lycopersicum and Vigna radiata. Further, it may help to understand the interface of TiO 2 nanoparticles with the environment and agriculture before its application to the field. © 2016, Joint Center on Global Change and Earth System Science of the University of Maryland and Beijing Normal University and Springer-Verlag Berlin Heidelberg.
Emerging trends in photodegradation of petrochemical wastes: a review
(Springer Verlag, 2016) Pardeep Singh; Ankita Ojha; Anwesha Borthakur; Rishikesh Singh; D. Lahiry; Dhanesh Tiwary; Pradeep Kumar Mishra
Various human activities like mining and extraction of mineral oils have been used for the modernization of society and well-beings. However, the by-products such as petrochemical wastes generated from such industries are carcinogenic and toxic, which had increased environmental pollution and risks to human health several folds. Various methods such as physical, chemical and biological methods have been used to degrade these pollutants from wastewater. Advance oxidation processes (AOPs) are evolving techniques for efficient sequestration of chemically stable and less biodegradable organic pollutants. In the present review, photocatalytic degradation of petrochemical wastes containing monoaromatic and poly-aromatic hydrocarbons has been studied using various heterogeneous photocatalysts (such as TiO2, ZnO and CdS. The present article seeks to offer a scientific and technical overview of the current trend in the use of the photocatalyst for remediation and degradation of petrochemical waste depending upon the recent advances in photodegradation of petrochemical research using bibliometric analysis. We further outlined the effect of various heterogeneous catalysts and their ecotoxicity, various degradation pathways of petrochemical wastes, the key regulatory parameters and the reactors used. A critical analysis of the available literature revealed that TiO2 is widely reported in the degradation processes along with other semiconductors/nanomaterials in visible and UV light irradiation. Further, various degradation studies have been carried out at laboratory scale in the presence of UV light. However, further elaborative research is needed for successful application of the laboratory scale techniques to pilot-scale operation and to develop environmental friendly catalysts which support the sustainable treatment technology with the “zero concept” of industrial wastewater. Nevertheless, there is a need to develop more effective methods which consume less energy and are more efficient in pilot scale for the demineralization of pollutant. © 2016, Springer-Verlag Berlin Heidelberg.
Grossly Polluting Industries and Their Effect on Water Resources in India
(wiley, 2021) Zeenat Arif; Naresh Kumar Sethy; Swati; Pradeep Kumar Mishra; Bhawna Verma
Industrialization is considered as the pillar of economic development and human welfare in India. Since the previous decade, industrial development has greatly affected water resources like rivers, lakes, groundwater, and so on. This is mainly due to the increase in the percentage of grossly polluting industries (GPIs) such as textiles, tannery, distillery, and drug industries. Since 2011, the number of GPIs increased from 1162â€‰units over 22 states/union territories (UTs) to 2743â€‰units over 36 states/UTs as per the Central Pollution Control Board (CPCB) report, of which about 84% of the GPIs are located in four states, viz. Uttar Pradesh (1218), Haryana (660), Andhra Pradesh (198), and Gujarat (191). According to the National Mission for Clean Ganga (NMCG), the wastewater generated by GPIs is 45% of total water consumption. This is mostly due to small-scale industries having a lack of effluent treatment plants (ETPs). These industries produce major pollutants like Cr from tanneries, organic pollutants from distilleries, dyes from textiles, and other toxic chemicals from drug and hazardous chemical industries, which affect both surface and groundwater resources. This has an adverse effect on aquatic ecosystems and human health both directly and indirectly. There are many initiatives and measures taken by central government like national water policies, revised effluent standards, establishing more common effluent treatment plants (CETPs), adopting projects like zero liquid discharge (ZLD) (reuse and recycling of entire industrial wastewater), and so on. Proper management and monitoring of these measures and policies would help in reducing surface and groundwater pollution. Hence, this chapter is focused on GPIs and their effect on water resources and the management of their discharging effluents. © 2021 John Wiley & Sons Ltd. All rights reserved.
Hydrothermal treatment of lignocellulose waste for the production of polyhydroxyalkanoates copolymer with potential application in food packaging
(Elsevier Ltd, 2022) Abhishek Dutt Tripathi; Pradeep Kumar Mishra; Kianoush Khosarvi-Darani; Aparna Agarwal; Veena Paul
Background: Bio-plastics are eco-friendly biopolymer finding tremendous application in food and pharmaceutical industries. Biodegradable polymer-based plastic such as PHAs (plyhydroxyalkanoates) possesses similar physicochemical and mechanical properties as posed by conventional plastic. PHAs does not cause any type of hazardous pollution upon disposal. However, the high production cost of PHAs makes its wider acceptability unsuitable at commercial level. This can be minimized by screening potential PHAs producing strains, selecting inexpensive raw material, optimized cultivation condition and by adopting efficient recovery and purification strategies. Scope and approach: The PHA upstream processing is expensive and contributes approximately 40% of total production cost. This can be minimized to greater extent by using inexpensive raw materials such as agro-industrial waste and lignocellulose waste (LCW). In recent time, LCW has gained more attention in bioprocess-based production owing to its nutritional composition. LCW is rich in complex polysaccharides such as lignin, cellulose, hemicellulose which are not easily digested. Hydrothermal processing of lignocellulosic materials causes a variety of effects including extractive removal, hemicellulose hydrolysis and alteration of the properties of both cellulose and lignin. The extracted digested residues can be effectively utilized in PHAs and copolymer synthesis. Key findings and conclusion: This review focusses on various aspects of hydrothermal processing of lignocellulosic waste for efficient and economical PHAs production. These bio-plastics specifically microbial produced bio-polymers such as PHAs find application in food industries as packaging material owing to their desirable water barrier and gas permeability properties in addition to complete biodegradability upon disposal without green-house gas emission. The present review deals with the production, recovery, purification, characterization and applications of PHAs and its copolymers using LCW as potential substrate. This review will also focus on different strategies adopted for efficient PHA production using hydrothermal treated LCW, its biosynthetic mechanism, extraction, purification, characterization and also biodegradability testing at lab and pilot plant level. In addition to that, the authors will emphasize novel PHA copolymers nanocomposites synthesis strategies and their commercial applicability. © 2022
Microbial beta glucosidase enzymes: Recent advances in biomass conversation for biofuels application
(MDPI AG, 2019) Neha Srivastava; Rishabh Rathour; Sonam Jha; Karan Pandey; Manish Srivastava; Vijay Kumar Thakur; Rakesh Singh Sengar; Vijai K. Gupta; Pranab Behari Mazumder; Ahamad Faiz Khan; Pradeep Kumar Mishra
The biomass to biofuels production process is green, sustainable, and an advanced technique to resolve the current environmental issues generated from fossil fuels. The production of biofuels from biomass is an enzyme mediated process, wherein β-glucosidase (BGL) enzymes play a key role in biomass hydrolysis by producing monomeric sugars from cellulose-based oligosaccharides. However, the production and availability of these enzymes realize their major role to increase the overall production cost of biomass to biofuels production technology. Therefore, the present review is focused on evaluating the production and efficiency of β-glucosidase enzymes in the bioconversion of cellulosic biomass for biofuel production at an industrial scale, providing its mechanism and classification. The application of BGL enzymes in the biomass conversion process has been discussed along with the recent developments and existing issues. Moreover, the production and development of microbial BGL enzymes have been explained in detail, along with the recent advancements made in the field. Finally, current hurdles and future suggestions have been provided for the future developments. This review is likely to set a benchmark in the area of cost effective BGL enzyme production, specifically in the biorefinery area. © 2019 by the authors. Licensee MDPI, Basel, Switzerland.
Optimization of pretreatment conditions for enhanced sugar release
(Taylor and Francis Inc., 2017) Deepika Kushwaha; Ishita Mishra; Neha Srivastava; Pradeep Kumar Mishra
Present investigation was done to evaluate various algal genera found in water bodies of Varanasi city. The potential of any biomass for biofuels (bioalcohols, biohydrogen, etc.) production depends on the quantity of extractable sugar present in it. Acid (H2SO4) and alkali (NaOH) pretreatment were performed, and H2SO4 was chosen due to its nearly double yield as compared with alkaline pretreatment. Response surface methodology was utilized for the optimization of operating parameters such as treatment temperature, time, and acid concentration. Sugar yield up to 0.33 g/g of dry biomass was obtained using cyanobacterial biomass of Lyngbya limnetica, at 100°C, 59.19 min, and H2SO4 concentration of 1.63 M. © 2017 Taylor & Francis Group, LLC.
Performance evaluation of solar dryer integrated with solar panel for drying of carrot (Daucus carota) vegetable
(Taylor and Francis Ltd., 2024) Mukul Sengar; Dhananjay Singh; Pradeep Kumar Mishra
Solar energy is a well-known and economically efficient energy source. Solar energy is harvested in two modes: one is direct and another is indirect. In the direct type, the global radiation is used directly to dry the food samples, while in indirect mode, solar energy is converted into electricity to operate the integrated exhaust fan for enhancement of the drying rate. Thermal analyses of the various components of the PVT hybrid dryer have been incorporated into this performance evaluation. Carrot has been chosen as a food sample because it has good moisture content and is used for nutritive purposes. The maximum ambient temperature has been monitored as 41°C at maximum global radiation conditions. The effect of the PVT system with solar dryer in both cases i.e. natural convection and forced convection have also been discussed in terms of temperature profiles of the drying chamber, sample temperature, and thermal efficiency. The thermal efficiency has been found as 55.3% for forced convection and 53.4% for natural convection. Similarly, a 3°C temperature increment has been found in food samples. Results have been supported and analyzed by the comparison between outcomes of natural and induced convection. © 2024 Indian Institute of Chemical Engineers.
Photocatalytic degradation of Acid Red dye stuff in the presence of activated carbon-TiO2 composite and its kinetic enumeration
(Elsevier Ltd, 2016) Pardeep Singh; M.C. Vishnu; Karan Kumar Sharma; Anwesha Borthakur; Pratap Srivastava; D.B. Pal; Dhanesh Tiwary; Pradeep Kumar Mishra
The present paper deals with photocatalytic degradation of effluents from dye industries which have known toxic impacts on flora and fauna. Nano composite of titanium dioxide having activated carbon (TiO2/AC) base was synthesized using sol-gel method. The synthesized catalyst was then characterized by Fourier Transform-Infrared (FT-IR) spectroscopy, Scanning Electron Microscopy (SEM), X-ray Diffractometry (XRD) and Brunauer Emmet Teller (BET) surface area analyzer. A synthetic solution of AR-131 dye was subjected to photocatalytic degradation using TiO2/AC nano composite as catalyst. The degradation mechanisms of dye (AR-131) via photo-catalysis were found to follow a first order kinetics mechanism (vis. Langmuir- Hinshelwood Model). Toxicity of spent catalysts was further investigated in seed germination of Vigna radiata. Enhanced seed germination along with elongation of root and shoot was noticed up to the concentration of 500 ppm confirming its non toxicity. © 2016 Elsevier Ltd.
Recent developments in photocatalytic degradation of insecticides and pesticides
(De Gruyter Open Ltd, 2023) Santosh Kumar Singh; Pradeep Kumar Mishra; Siddh Nath Upadhyay
Widespread use of pesticides in agricultural and domestic sectors and their long half-life have led to their accumulation in the environment beyond permissible limits. Advanced chemical oxidation methods including photocatalytic degradation are being widely investigated for their mineralization. Photocatalytic degradation is the most promising method for degrading pesticides as well as other organic pollutants. Titanium dioxide with or without modification has been widely used as the photocatalyst. Some research groups have also tried other photocatalysts. This review presents a critical summary of the research results reported during the past two decades as well as the scope for future research in this area. © 2021 Walter de Gruyter GmbH, Berlin/Boston.
Study on Blood Serum Levels of Heavy and Trace Metals in Chronic Non-Healing Wounds
(SAGE Publications Inc., 2024) Ruhi Dixit; Naveen Kumar Chaudhary; Pradeep Kumar Mishra; Pradeep Srivastava; Satyanam Kumar Bhartiya; Arvind Pratap; Somprakas Basu; Vijay Kumar Shukla
Wound healing is a complex, highly regulated process that is important in sustaining the skin barrier function. The etiologic relation of specific metals is not adequately described for chronic non-healing wounds. The aim of this study was to estimate heavy and trace metals in chronic non-healing wound and their association with wound healing. The levels of zinc, selenium, copper, magnesium, chromium, cadmium, iron, and lead were estimated in serum of chronic non-healing wound patients using atomic absorption spectrophotometry. The tests were carried out in 50 patients with chronic non-healing wound and thirty healthy volunteers as control. The serum levels of elements namely zinc, selenium, copper, magnesium, and chromium were significantly reduced in chronic non-healing wounds (P <.001) as compared to control. Lead and cadmium levels had shown the significantly increasing trend in chronic non-healing wound cases (P <.001). The present study demonstrated a significant decrease in serum, levels of selenium, zinc, copper, magnesium, iron, and chromium levels in patients with chronic non-healing wound indicating an association between these elements and wound healing. To summarize the findings of our research, hence trace elements were decreasing in chronic non-healing wound patients suggesting their role in wound healing. © The Author(s) 2022.
Synthesis and catalytic activity of Cu-Cr-O-TiO2 composites for the thermal decomposition of ammonium per-chlorate: enhanced decomposition rate of fuel for solid rocket motors
(Royal Society of Chemistry, 2017) Harish Kumar; Prahalad N. Tengli; Vijay Kumar Mishra; Pankaj Tripathi; Dan Bahadur Pal; Pradeep Kumar Mishra
This study presents the sol-gel synthesis of Cu-Cr-O·nTiO2 particles calcined at different temperatures and their catalytic effects on thermal decompostion of AP. The study focuses on the impact of crystallite size, shape and concentration of TiO2 in the catalyst composition on the thermal decomposition behaviour of ammonium per-chlorate (AP). During synthesis, the molar ratio of Cu/Cr was kept to 0.7 and TiO2 nanoparticles were added into Cu-Cr-O-citric acid solution at different molar ratios to form three different compositions of the catalyst Cu-Cr-O·nTiO2 (n = 0.5, 0.7 and 0.9 mol%). The effect of temperature on the thermal, structural and spectroscopic properties of the different Cu-Cr-O compositions was also studied by calcining them at two different temperatures, 300 and 1050 °C. Post synthesis characterizations of the prepared catalysts were carried out by using XRD, FT-IR, SEM, EDAX and TEM (with SAED pattern) techniques. The desired qualification of Cu-Cr-O-citric acid (the precursor of the catalyst) and the final compositions of the catalysts were carried out by using thermogravimetric and differential thermal analysis (TG-DTA) techniques. The efficiency of the synthesized catalysts was evaluated on thermal decomposition behaviour of AP using TG-DTA techniques. The Cu-Cr-O·nTiO2 composition with the molar ratio of n = 0.7 was found to be the most efficient catalyst for decomposition of AP; it was much better than other laboratory prepared samples (n = 0.5 and 0.9) as well as the industrial catalyst (i.e. activated copper chromite (ACR); Cu-Cr-O). Further experimental work showed that addition of 10 wt% Cu-Cr-O·0.7TiO2 into AP significantly lowered the AP decomposition temperature to 306 °C from 385 °C and was accompanied by a very sharp exothermic peak indicating a single stage decomposition. The excellent finding of the study was also verified by heat of reaction (i.e. calibrated delta H) values. This study finds potential application due to the remarkable enhancement in the thermal decomposition rate of the AP used as oxidizer in propellant of solid rocket motors (SRMs) and space vehicles (SVs) at lower decomposition temperature. The fast decomposition rate of oxidizer at lower decomposition temperature enhances the efficiency of fuel which ultimately will enhance the efficiency of SRMs and SVs. © The Royal Society of Chemistry.
The effect of reduced graphene oxide on the catalytic activity of Cu-Cr-O-TiO2 to enhance the thermal decomposition rate of ammonium perchlorate: An efficient fuel oxidizer for solid rocket motors and missiles
(Royal Society of Chemistry, 2017) Harish Kumar; Prahalad N. Tengli; Vijay Kumar Mishra; Pankaj Tripathi; Awani Bhushan; Pradeep Kumar Mishra
Reduced graphene oxide (rGO) modified transition metal oxide based composites were successfully synthesized via a sol-gel assisted Hummers' method. The present study includes the synthesis of CuCr2O4·0.7TiO2, the synthesis of rGO and the synthesis of rGO modified CuCr2O4·0.7TiO2. In order to synthesize the desired catalyst, rGO and Cu-Cr-O-0.7TiO2 were synthesized individually. The CuCr2O4·0.7TiO2 composite was synthesized via a sol-gel method. Reduced graphene oxide (rGO) used as a modifier in the catalyst, was also synthesized in the laboratory and was calcined at high temperature (1050 °C) to improve its activity. Finally, Cu-Cr-O-0.7TiO2 was modified with 10 wt% rGO. The post synthesis characterizations were performed using various instrumental techniques including X-ray diffraction (XRD) for phase analysis, Fourier transform infrared (FTIR) and Raman spectroscopy for molecular interactions, scanning electron microscopy (SEM) for surface morphology, energy dispersive X-ray analysis (EDX), elemental analysis and X-ray photoelectron spectroscopy (XPS) for binding energy. The catalytic efficiency of the synthesized composite catalyst samples based thermal decomposition of the host material (i.e. AP) was determined by differential thermal analysis (DTA) and thermogravimetric analysis (TGA). The rGO modification into the Cu-Cr-O-0.7TiO2 tri-metallic composition made it the most promising catalyst for the thermal decomposition of AP, due to the tremendously high electrical and thermal conductivity of rGO. Different amounts (2.5, 5.0, 7.5 and 10 wt%) of Cu-Cr-O-0.7TiO2-rGO were added to ammonium perchlorate (AP) to investigate its effect on the thermal decomposition of AP, which is a well known oxidizer used worldwide in the solid composite propellant (SCP) in modern rocketry. The 5 wt% of catalyst (Cu-Cr-O-0.7TiO2-rGO) addition into AP exhibited the remarkably enhanced thermal decomposition of AP. Finally, the burn rate of SCP was examined with 5 wt% catalyst modified AP. The 5 wt% of catalyst modified AP exhibited 175.31% higher burn rate of SCP, compared to the burn rate of pure AP added SCP. Furthermore, when it was compared with an industrial catalyst, i.e. activated copper chromite (ACR), it showed 133.61% higher burn rate of SCP. The SCP exhibited excellent ballistic performance with 0.6% of catalyst in AP, which enhanced the burn rate from 4.866 mm s-1 (for SCP having pure AP) to 8.531 mm s-1 (for SCP having catalyst added AP) and 6.385 mm s-1 (for SCP having industrial catalyst added AP) at 33 bar. © 2017 The Royal Society of Chemistry.