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Coordination Complexes of Vanadium Featuring O-N-O and O-N-S Donor Ligands: Study of Reactivity and Solution Behavior
No full textThe presence of transition metals in our body in form of metallo-proteins and metallo-enzymes has motivated researchers to find its potential in field of pharmaceutical industry. Among the transition metals, the chemistry of vanadium and its complexes has become a fascinating area of research after the discovery of vanadium as a bio-essential element and its presence in many naturally occurring compounds. It has stimulatory effect on the growth of algae and plants, participating in various enzymatic reactions like, the inhibitory action of vanadate(V) on Na, K-ATPase, haloperoxidases and some nitrogenases in nitrogen-fixing Azotobacter. Vanadium is also under research for its probable anti-cancer therapeutics due to its long proven insulin-like behavior and reported reduction of hyperlipidemia and hypertension to suppress tumor cell growth. Keeping these factors in mind, in this dissertation the chemistry of a wide variety of new versatile variable valence mono-/di-nuclear non-oxido and oxido vanadium(IV/V) complexes of some tridentate binegative ONO or ONS donor Schiff base as main and neutral N,N-donor as co-ligand systems are reported, with special reference to their pharmacological activity and solution property. All the synthesized ligands and their corresponding metal complexes have been successfully characterized by several physicochemical (elemental analysis), spectroscopic (UV-vis, IR, NMR and EPR), spectrometric (ESI‒MS) and electrochemical (cyclic voltammetry) methods. The exact geometry of the complexes was further confirmed by single crystal X-ray diffraction (SC-XRD) analysis. In order to get additional information, molecular structure and spectroscopic properties such as UV-vis and EPR of some of the above complexes was simulated by DFT (density functional theory) methods. With a view to evaluate the biological activity, interaction with DNA and several proteins (HSA, BSA, cytochrome c, ubiquitin and lysozyme) through analytical and molecular docking approaches and in vitro antiproliferative activity against different cancer cell lines [ovarian (A2780), prostate (PC3), cervical (HeLa) and colon (HT-29)] as well as non-cancerous cell lines [mouse embryonic fibroblast (NIH-3T3) and normal fibroblasts (V79)] of some of the above complexes was studied. The results indicated that some of the complexes showed significant binding affinity towards both DNA and proteins. In vitro antiproliferative activities of the studied complexes reveal them to be potential lead molecules for drug designing and also the complexes studied herein showed similar, or in some cases improved in vitro cytotoxicity (IC50 values in the range 1.1−42.7 μM) as compared to the various clinically reported prevalent chemotherapeutic drugs. Apart from that, the solution behavior of the synthesized mono- and di- nuclear vanadium(IV/V) compounds has also been studied in order to understand their transformation, interconversion, changes in coordination geometry, nuclearity and redox processes and mode of interaction with the biological systems and mechanistic action under physiological conditions which were not explored earlier. Finally, a plausible mechanism of such solution behavior has also been discussed in details
Performance Evaluation of Eichhornia Crassipes for Kitchen Wastewater Treatment
No full textKitchen wastewater (KWW) is a type of grey wastewater that has garnered significant attention due to the presence of organic pollutants and oil and grease. Eutrophication in water bodies and chocking of sewer lines are common hazardous impacts due to KWW. Stagnant KWW invites serious diseases such as malaria, filarial, and dengue. The present water crisis demands the reuse of KWW for non-potable purposes. In this study, the potential reusability of KWW in irrigation was analyzed to reduce the present freshwater demand. An initiative has been taken to collect the KWW samples from an educational institute in India to check its suitability for irrigation. The samples were characterized by their physical, chemical, and bacteriological properties. The characterized data were compared with the standard limit for irrigation Food and Agriculture Organization (FAO 1994) and the United States Salinity Laboratory (USSL 1954). Apart from the irrigation standards, the characterized data were also compared with sodium adsorption ratio (SAR), residual sodium carbonate (RSC), sodium percentage (Na%), magnesium hazard (MH), Kelly’s ratio (KR), and permeability index (PI) to get better clarity. Characterized data showed the absence of carbonate, fluoride, chromium, and Escherichia coli in KWW. Parameters like pH, chloride, iron, copper, magnesium, lead, nickel, sodium, calcium, zinc, aluminum, and sodium adsorption ratio were within the permissible limit, whereas bicarbonate, total dissolved solids, electrical conductivity, sulphate, and potassium exceeded the limit as per FAO (1994) standard. The result obtained from the USSL (1954) classification system suggested that 30.77% of KWW samples were safe for irrigation. Moreover, its quality was found to be safe for irrigation based on SAR, Na%, KR, and MH. The study showed that for RSC and PI indices, the KWW needs to be treated for sustainable reuse. For better decision making of KWW reuse in irrigation, the output of Mamdani fuzzy inference system (MFIS) was compared with the USSL (1954) classification system. Overall agreement between USSL (1954) and MFIS was found to be 55.6% for KWW. Hence, there is a need for raw KWW treatment. In this study, the phytoremediation method using Eichhornia crassipes (EC) was used for KWW treatment because of its low-cost. For performance evaluation of EC, field experiments were conducted for both raw and decomposed KWW. From treatment analysis of raw KWW with EC for 21 days (monitored at 3 days of an interval), it was observed that nitrate nitrogen and ammonium nitrogen concentrations reduced to 98.57% and 81.82%, respectively, within 15 days, whereas pH value increased towards neutral range from 4.35 to 6.48. It was also found that EC showed good reduction efficiency for BOD5 (77.62%), ammonium nitrogen (81.82%), total organic carbon (38.33%), and total suspended solids (95.97%) as compared to control (KWW sample without EC). Phytoremediation using EC reduced potassium concentration to 75.51%. An increase of 47.01% biomass of EC was observed for 21 days of the experiment. Further, efficiency of EC was evaluated for the decomposed KWW sample. Physical and chemical parameters were monitored for 28 days (monitored at 7 days of an interval). Initially, control (raw KWW sample without EC) and raw KWW+EC were kept for two weeks, and then in control (decomposed KWW sample), EC was added and kept for the next two weeks. In the initial sample, the concentration of electrical conductivity, total dissolved solids, nitrate nitrogen, ammonium nitrogen, phosphate phosphorus, and potassium were found to be exceeded the standard limit of irrigation water quality. However, after 28 days for raw KWW+EC, the concentrations of these parameters were reduced to 63.71%, 63.71%, 99.01%, 94.36%, 98.05%, and 83.30%, respectively, and found within the limit. An increase of 51.73% and 117.34% biomass (fresh weight) were observed for raw KWW+EC and decomposed KWW+EC, respectively. Higher value of bioconcentration factor (BCF) was found for iron (8,363.40) in raw KWW+EC, whereas for decomposed KWW+EC higher BCF value was found for iron (1,481.33), nickel (1,497.3), zinc (5,225.4) and mercury (1,286.9). It was also observed that calcium, copper, magnesium, sodium, lead, and potassium showed translocation factor (TF) >1 in raw KWW+ EC, and for decomposed KWW+EC, calcium, magnesium, sodium, and mercury showed TF > 1. Apart from the field experiment, cost-benefit analysis of KWW treatment project was carried out using the Net Present Value method. Both the lower and upper bound of the selling price of treated KWW and discount rates were estimated in order to have a profitable KWW treatment project. The effect of soil and crop selection on the revenue generation during the reuse of treated KWW was also studied. The possible solution to reduce present water stress over different cities of India was also highlighted. This study can be beneficial for reducing the wastewater handling problem and solving the demand for freshwater
Flow Analysis of Compound Channels with Rough Floodplains
Get PDFThis research aims at flow in compound channels using physical modelling, are important for understanding flow and its behaviour. Experiments in straight compound channels, with differential roughness in main channel and flood plain beds are conducted to analyse two-phase flow at high river stage. Stage- discharge, boundary shear stress, velocity distributions and secondary currents are all measured, and the results are presented graphically and with tabulated summaries. Although it is known that Manning's roughness coefficient varies with river stage without accounting the effect of momentum transfer at the interface of main channel and adjoining flood plains, information on this subject is scarce, forcing practitioners to rely on empirical equations or their judgment to calculate the differences. The aim of this study is to look into the trends of Manning's roughness coefficient variance over width ratio, relative flow depth, and roughness ratio. Along the channel's wetted perimeter, this experimental channel allowed for a thorough investigation of composite roughness aspects. Physically, the composite/compound roughness on the wall as well as the shape of the channel modifies the velocity distribution across the cross section, and hence alters the resistance coefficient. The existing equations are typically intended for simple channels. When these formulas are proposed for compound and composite channels based on different assumptions about the relationships of the discharges, velocities, forces, or shear stresses between the component subsections and total cross section, it provide a significant error in estimating the composite roughness of compound channels. An analytical method (NCRM) is proposed to predict the composite roughness as a function of geometric, roughness, hydraulic parameters and the momentum transfer between main channel and floodplain interfaces. The momentum transfer magnitude is quantified in terms of interface length of main channel and flood plain (Imc or Ifp). The efficacy of the methods is checked against a collection of wide range of data sets. It also validated with natural river data sets. Predicting the stage-discharge curve of a compound channel is difficult due to additional flow resistance caused by momentum exchange between subsections, and it is much more difficult when the main channel and floodplains have a differential roughened boundary. There are few approaches that rely on calculation of the momentum transfer coefficients of compound channels to determine total flow, despite the fact that there are multiple models for predicting discharge. The study introduces an optimized procedure with an innovative methodology for testing the momentum transfer coefficients of compound channels with differentially roughened boundary in subsections using a sequence of experiments. The momentum transfer coefficients at the vertical and horizontal interfaces (χvl, χvr, and χh) of a compound channel can be accurately predicted using the suggested technique. Calibration performance reveals that the proposed model is capable of predicting the stage-discharge results, which are well compared to other existing approaches. The error statistic is established, confirming that the present method is providing better discharge results as compared to the other approaches. The method is successfully applied to the FCF, UK Wallingford, and the river data sets of compound channels of different roughness, flow, and geometric conditions. Flow discharge calculation in rivers is one of the parameter in flood management. In this study the hydraulic characteristic of open channel is analysed. The methods for evaluating the critical depth in a compound channel are also reviewed and assessed against experimental data. In this regard distribution of Momentum Coefficient (β), Energy Coefficient (αk), Depth- Froude’s Number, Specific energy curve are evaluated. The kinetic energy coefficient is estimated by the divided channel method with diagonal interface (DCM-D). Using the kinetic energy coefficient the Froude number is corrected. The critical depth and specific energy curve are also verified with the corrected value of Froude number. The method is also evaluating the lateral flow regime in a compound channel and assessed against experimental data
Dielectric Properties of Microwave Processed CaCu3Ti4O12 - Based Ceramics and Related (0-3) Epoxy-composites
No full textCaCu3Ti4O12 (CCTO) based ceramics are technologically important due to large frequency and temperature independent dielectric constant [104-105 at room temperature (RT)]. This material has drawbacks in terms of high ‘tan δ’, low dielectric break down strength (Ebd) and low volumetric energy density (Uvol). In this present work, high ‘tan δ’ value is utilized for synthesis by adopting microwave assisted solid state reaction (MASSR) and an attempt has been initiated towards the improvement of ‘tan δ’, ‘Ebd’ and ‘Uvol’ of CCTO based ceramics by incorporating Al3+, Nb5+, and (Nb5+0.5Al3+0.5) as substitutes of Ti4+site; therefore perturbing the TiO6 octahedron. Ceramics are synthesized via microwave assisted solid state reaction [MASSR] synthesis route. Ceramics used for this work are: (1) CaCu3Ti4O12, (2) CaCu3Ti4-xAlxO12 [CCTAxO], (3) CaCu3Ti4-xNbxO12 [CCTNxO], (4) CaCu3Ti4-x(Nb0.5Al0.5)xO12 [CCT(NA)xO]; x = 0.025, 0.05, 0.075, 0.1. Starting with single phase CCTO calcined powder; effect of sintering temperature in between 1000 to 1075 °C (with a step size of 25 ° and ceramics are assigned as CCTO1, CCTO2, CCTO3, and CCTO4 respectively) was investigated. CuO melted phase increases with increasing temperature. Maximum ‘εr’ found in CCTO3 (sintered at 1050 °C) is ~ 15,000 with tan δ ~ 0.15 at 100 Hz and amount of CuO secondary phase ~ 16 % (estimated from Rietveld analysis). In addition, non-ohmic voltage exponent (‘α’), breakdown field strength (‘Ebd’), volumetric energy density (Uvol), Shottky barrier height (ϕB) and barrier width related parameter (β) of CCTO3 are ~ 3.72, 9.7 kV/cm, 0.062 J/cm3, 0.836 eV and 2.4×10-3 (eV) V-1/2 cm-1/2 respectively. In modified CCTO ceramics, CuO secondary phase also appeared during sintering at 1050 °C. Variations of CuO phase with guest atom and ‘x’ are quite anomalous. Rietveld analysis has been performed to quantify the amount of monoclinic CuO phase. Microstructure evolution reveals the presence of melted phase and its Cu-rich nature has been confirmed through selective area EDX. Distinct variations in microstructure in terms of grain size, amount of melted phase, density are observed in this work. Dielectric, modulus, impedance, ac conductivity are studied as functions of frequency and temperature. CCTA0.05O, CCTN0.075O, and CCT(NA)0.075O are showing improved dielectric properties among individual batch of modified CCTO ceramics. Amount of CuO is found in between 10-16 % for the above mentioned composition. CCTN0.075O shows highest ‘εr (100 Hz)’ ∼ 37,239 with ‘tan δ’ ∼ 0.37 among all CCTNxO ceramics as well as other batches at RT. CuO secondary phase is ~ 10.5 %. ‘εr’ rapidly drops to ∼ 23,889 with ‘tan δ’ ∼ 0.223 and ∼ 5,708 with ‘tan δ’ ∼ 0.55 at 1 kHz and 1 MHz respectively. Lower ‘Ebd’∼ 4.58 kV/cm and ‘Uvol’ ∼ 0.035 J/cm3 are found for this composition. ‘ϕB’ and ‘β’ are ∼ 0.79 eV and ∼ 2.8 ×10-3 (eV) V-1/2 cm-1/2 respectively. CCTA0.05O shows maximum ‘εr (100 Hz)’ ∼ 23,000 with tan δ ∼ 0.08 among all CCTAxO ceramics at RT. The amount of secondary CuO phase is ∼ 12 % and high ‘Ebd’∼ 24.02 kV/cm, along with ‘α’ ∼ 5.13 and Uvol ∼ 0.59 J/cm3 has been found. ‘ϕB’ and ‘β’ are 0.84 eV and 1.5×10-3 (eV) V-1/2 cm-1/2 respectively. Maximum ‘εr (100 Hz)’ ∼ 29,648 with tan δ ∼ 0.2 has been found in CCT(NA)0.075O among all CCT(NA)xO ceramics. ‘εr (1 MHz)’ ∼ 12,995 is quite high with tan δ ∼ 0.45. Amount of CuO phase is ∼ 14.7 %. This composition shows ‘εr’ ∼ 24,173 at 1 kHz with ‘tan δ’ ∼ 0.15, and ‘εr’ remains highest throughout the frequency range between 1 kHz to 1 MHz. Maximum ‘Ebd’~ 28.8 kV/cm (at 1 mA/cm2 current density), along with ‘α’∼5.51 and highest energy density Uvol ∼ 1 J/cm3 has been achieved in CCT(NA)0.075O ceramic. Formation of ‘Shottky barrier’ is verified and maximum ‘ϕB’ ∼ 0.92 eV is observed in CCT(NA)0.075O. Barrier width parameter ‘β’ is ∼ 1.8 ×10-3 (eV) V-1/2 cm-1/2. Improvement in dielectric properties is analyzed on the basis of IBLC model in presence of CuO secondary phase. AC conductivity shows correlated barrier hopping mechanism (CBH). From the above results, CCT(NA)0.075O is considered as the best in terms of ‘εr’, ‘tan δ’, ‘Ebd’, ‘Uvol’ ‘α’, ϕB etc. In addition, an attempt has been initiated to prepare Epoxy-based composites by taking CCT(NA)0.075O (abbreviated as CCTNAO in Chapter 7) and conducting Al particle as fillers. Filler volume is restricted within 40 % in all composites. Composites prepared for the purpose are 1. (1-x) Epoxy – x Al ; x = 0, 0.05,0.1, 0.2, 0.3, 0.4 ,2. (1-x) Epoxy – x CCTNAO ; x = 0, 0.05,0.1, 0.2, 0.3, 0.4, 3. (1-x) [0.8Epoxy – 0.2 CCTNAO] – x Al ; x = 0, 0.05,0.1, 0.15, 0.2 While studying (1-x) Epoxy – x Al composites, maximum ‘εeff’ ∼ 150 achieved for x = 0.4, at 1 kHz, but loss became so high (tan δ > 10). But, the ‘εeff’ ∼ 70 with low loss (∼ 0.5 at 1 kHz) has been found for x = 0.3. At RT, highest ‘εeff’ ∼ 33.37 with tan δ ∼ 0.1 at 1 kHz has been found in 0.6 Epoxy - 0.4 CCTNAO, but ‘tan δ’ reduced to ∼ 0.055 beyond 100 kHz. Maximum ‘εeff’ ∼ 77.5 with tan δ ∼ 0.154 has been found in 0.64 Epoxy – 0.16 CCTNAO – 0.2 Al composite at 1 kHz. ‘εeff’ falls off to ∼ 72.5 with tan δ ∼ 0.1 at 10 kHz. Beyond 10 kHz, ‘tan δ’ is < 0.1. At 1 kHz, ‘εeff’ is ∼ 50 with tan δ ∼ 0.09 observed in 0.68 Epoxy – 0.17 CCTNAO – 0.15 Al composite. At 10 kHz, ‘εr’ is ∼ 47, with tan δ ∼ 0.06. Experimentally measured values of ‘εeff’ is in close agreement with EMT model (η = 0.13) and Yamada Model (η = 7) in (1-x) Epoxy – x CCTNAO composites. Proposed empirical power equation, εeff = εm (1+x)n with n ∼ 10 has a considerable agreement with the experimental data of (1-x) Epoxy – x Al and (1-x) [0.8Epoxy - 0.2 CCTNAO] – x Al composites
Sequestration of Activated Carbon from a Wasteland Weed and its Application in High Performance Supercapacitor-based Energy-Storage System
Get PDFThe urge to satisfy the growing energy demands in the present scenario, the world is exploring novel renewable sources, producing various energy forms as well as searching alternative to non-renewable sources. The plants and raw organic matters are otherwise known as biomass, used to explore in several segments like biofuels, biochars and energy storage applications. Supercapacitors, otherwise known as electrical double layer capacitors (EDLCs), are storage devices with advantages of high-power density, long cycle life, safe operation and shelf life. The above mentions make EDLCs, a promising candidate for next generation energy storage device. It is a well-established fact that activated carbon is manifested as an important adsorbent to be used in numerous applications over the years. The carbonaceous material with small and low volume pores leads to activated carbon, with excellent adsorbent media owing to high surface area, free valencies, porous attribute, surface reactivity and good adsorption capacity. The synthesis of various forms of activated carbon has been investigated frequently by numerous researchers using several chemical agents. The current experiment is envisaged upon highly porous carbon with ZnCl2 and ZnCl2-ethanol activation. The planning of experiment is optimized with a suitable statistical method i.e., Taguchi orthogonal array, to get appropriate data along with improved field performance, reliability and low cost. The optimum factors affecting entire synthesis process and surface properties are determined with Taguchi L9 orthogonal array and ANOVA (analysis of variance) technique. The present study speaks of the synthesis of wild sugarcane or Saccharum spontaneum, as the prime sample, which is processed in to porous carbon. The raw material is found abruptly in the riverside, possessing nearly no use to the mankind, thus considered as a wasteland weed. The chemical treatment of the samples is performed with ZnCl2 as a major activating agent. The ZnCl2 and ZnCl2-ethanol activated carbons are synthesized with distinctive impregnation ratio (1-3) and carbonization temperature (500 ℃ - 800 ℃). The samples are characterized to observe the surface properties in terms of functionalities, morphologies, surface area and porosity. The best-found sample with optimum results is further tested in electrochemical storage system for EDLC application. The sample synthesized with ZnCl2-ethanol activation, at 600 ℃ shows optimum performance in terms of surface area (1590 m2/g) and porous properties. The same is reflected in the sample for energy storage performance. In an aqueous 1M H2SO4 electrolyte, the specific capacitance of 561 F/g and 275 F/g is achieved in half-cell and full-cell studies, respectively. The enhancement in electrochemical properties is clear with addition of redox additives. Herein, the incorporation of 0.01M hydroquinone, a redox agent, results raise in specific capacity up to 1392 C/g (half-cell) and 658 C/g (full-cell). Similarly, remarkable cycle stability of 77% after 5000 cycles, in HQ-incorporated aqueous electrolyte is obtained, evidencing high performance of EDLC device. A parallel trend is followed in energy density, power density and other relevant electrochemical properties as well
Development of Gold and Gold/semiconductor Nanostructures for Plasmonic and Photo/Electro-Catalytic Applications
No full textA simple, scalable one-pot synthesis route for ‘highly active’ Au nanoparticles (NPs) using oxalic acid (OA) as reducing agent was developed. At [Au3+]:[OA] of 1:3 under 50 C and microwave heating yielded highly active {110} facet exposed rhombic and squashed dodecahedron NPs (R&SD). Kinetics and mechanism of formation were studied in detail. The catalytic activity of these NPs were tested for 4-nitrophenol hydrogenation. Also, metal enhanced fluorescence (MEF) and 1O2 generation (MESOG) of bioactive Rose Bengal (RB) dye by these NPs were studied. The hydrogenation rate was almost double, MEF increased 5 times and MESOG generation increased significantly for R&SD compared to other shaped NPs. Such high plasmonic activity owns to electromagnetic field enhancement (hot-spots) at sharp edges and corners of Au NPs. For stable, long term use of NPs, they were loaded on natural kaolinite clay. They showed high activity in catalytic hydrogenation of 4-nitrophenol, SERS signal enhancement of RB. Similarly, kaolinite-TiO2 (KT) composite were successfully prepared by OA catalyzed sol-gel method and co-doped with N, S (KTN,S). TiO2 NPs of 5-10 nm got deposited uniformly over clay. Also, presence of electrolyte (E) and Au NPs on KT (AKT) on photocatalytic activity were tested. The methylene blue degradation efficiency for various catalysts were of the following order, P25<KT<KT-E<AKT<AKT-E<AKTN,S-E. Stability and reusability study showed just 2-4 % drop in activity after 5 cycles. Photocatalytic esterification was also highly efficient by KTN,S, converting about 85% of oleic acid to methyl oleate. Further, a new process was developed to prepare CdS QD sensitized hollow TiO2 NPs (CdS/h-TiO2) called ‘core utilization method’. They were tested as photoanode for photoelectrochemical (PEC) ‘water-splitting’ and compared with some standard NPs. PEC activity was also tested in presence of Au and Au@SiO2 core-shell NPs and found to have positive impact on the photoanode. The charge transfer resistance was considerably less and electrons lifetime was high for these photoanodes compared to similar reported systems
Beliefs about Etiology, Help-seeking and Consequences of Mental Illness: A Study on Tribal Patients from a Psychiatric Setup
No full textCultural disparity affects the Indian mental health care system that ranges from perceptions of etiology, treatment-seeking help-sseking, and management. The preference of treatment seeking is also influenced by culture. In India, varied and diverse modern and traditional healers are found in each corner, throughout the country to alleviate mental illness. Folk and religious healers are the predominant choices for the majority of the population. Being home to the largest tribal population of the world, India, with 705 tribal groups, has a greater vulnerability to mental health issues for a variety of reasons. In the case of tribal society, magico-religious practices are frequently resorted to the treatment of various illnesses, including mental illness. They have traditional beliefs, customs, and practices to deal with mental illnesses, which have not been explored much. Attributing supernatural powers as the prevalent etiology because of a strong belief in those forces in their culture, lack of awareness about mental illnesses, inaccessible, inadequate or no modern medical facilities could be the major barriers among the tribal populace to seek healthcare from the tertiary healthcare centers. The objectives of the present study are 1) to explore the beliefs about the etiology of mental illness among the tribal patients visiting a psychiatric setup; 2) to find out the prevalent help-seeking practices of mental illness by the patients; 3) to explore the consequences of mental illness on patients and their family members. The proposed study has applied a ‘mixed method approach’ to achieve the objectives of the study. The proposed study has been carried out in the institutional setup. The researcher has selected the Department of Psychiatry, Ispat General Hospital (IGH), Rourkela, Odisha. IGH is a multi-specialty hospital located in sector 19 of Rourkela city. The present study has fifty cases of tribal patients with mental illness. The sampling procedure had followed the ‘purposive sampling’. In the current research, a semi-structured interview schedule was designed to collect and document information about tribal patients visiting a psychiatric set-up. Two types of data sets, such as (i) qualitative and (ii) quantitative, were obtained from the cases studied. The researcher has used content analysis to analyze the qualitative data and the simple percentage ratio method has been employed to analyze the quantitative data. The study has been approved by the Ethical Committee Review Board of Ispat General Hospital (IGH) Rourkela, Odisha and Institute Ethical Committee, National Institute of Technology Rourkela Odisha India. The major findings of the study are presented thematically in the following paragraphs: Beliefs about the etiology of mental illness: Nearly about 40% of the patients with mental illness believe in supernatural factors as the main etiology of mental illness. Sixty percent of the tribal patients with mental illness believe in natural etiology of mental illness i.e., due to different stress, western physiology, and non-western physiology. Half of the respondents (48%) reported that the state of mental illness is a very serious illness. Suicidal ideation or fear to die is the main dread among most of the respondents (40%). Local nomenclature used by the people to denote the mental illness is Mundi/Munda Kharap, Mental dosha, Dimag bimari, Bhut lagiba, and Manasika bikruti, etc. Help-seeking practices for mental illness Nearly one-third (36%) of the patients with mental illness consulted the traditional healers and medical professionals, respectively, after the onset of the illness in the first instance. The traditional healers include all types of healing other than modern health care practices. It includes faith healers, religious healers, astrologers, temple healing, and local herbal healers, etc., which follow the non-scientific way of healing practices. The respondents taking no action accounted for 28% at the onset of mental illness due to the absence of awareness about mental illness, which may become a leading cause for aggravation of illness at the later stage. The notable reasons for choosing modern health care practices are: ‘cure the illness at the earliest’ (90%), ‘patient’s behavior/pain was unbearable’ (74%), ‘medical professional/ doctor is well known in the area’ (72%), ‘no other options to get cure of the illness’ (72%). The mean duration between the onset of the illness and the first psychiatric consultation is 23.42 months. The range of the consultation varies from one month to 120 months. The majority of the patients (88%) are not interested in hospital stay for the reasons like: a) there is no illness (20%); b) the psychiatric ward is not patient’s friendly (20%); c) unwillingness of the caregivers (family members) for the hospital stay (76%). Easy availability is the foremost motivational factor for approaching traditional healing practices. About one-third of the respondents (36%) consulted both traditional healers and psychiatrists simultaneously to cure the illness as earliest and have trust in the traditional healing. Nearly one-third (30%) of the patients with mental illness performed ritual practices to cure the illness at the earliest. Consequences of mental illness on the patient and their family members Marriage and mental health problems are closely related and multi-faceted ones. The evidence shows that there is an adverse effect of mental illness on marriage and marital life among the patient with mental illness. Mental health problems are working as a conflagration in marriage and marital life in the Indian marriage system. Patients have reported a decrease in appetite pattern (56%) of patients, deterioration in health condition (44%), and deterioration in the working ability (56%) after diagnosis of the illness. The researcher found that the effect of mental illness is on education, marriage, financial problem, family stress, disruption of family routine activities, physical abuse and violence in the family, social isolation, lack of caregiver’s personal care and care to other children in the family and damage in household accessories. Besides filling some gaps in the literature, the findings sometimes affirm and sometimes appear to contradict what has previously been written. The current study makes significant contributions in a multi-dimensional approach
Structural characterization and modelling of fly ash brick masonry
No full textThe disposal of fly ash is an environmental challenge globally, and the only viable solution for its mass disposal is its use in the construction industry, especially for brick production. Hence, recent times saw substantial growth in masonry structures using fly ash bricks in India, where coal-based power plants dominate the power sector. However, the performance of a masonry structure is dependent upon the properties of the bricks along with several other factors. Hence, the evaluation of fly ash brick properties is essential for quality masonry construction. The present research is an effort to study the engineering properties of fly ash brick unit and masonry on a large scale, establish the correlation among these properties, and quantify variability associated with different strength properties. Basic engineering properties like water absorption, initial rate of absorption, dry density, and compressive strength is studied on a large no of brick specimens, and the obtained result is checked for its suitability in quality construction. Among all the parameters, brick compressive strength is the key property that strongly influences the masonry compressive strength. Hence, the proper information regarding the brick compressive strength is essential before using it in masonry work. However, the evaluation of compressive strength requires access to sophisticated instruments, which is generally not available in the majority of the construction sites. This calls for the development of an alternative method that could provide first-hand knowledge on the strength and quality of brick units without the need for any large testing equipment. For this purpose, the correlation between the compressive strength and other easily measurable parameters is studied and a mathematical model is developed to predict the fly ash brick compressive strength using other parameters through experimental results and statistical correlation. An empirical model is also proposed to predict the compressive strength of fly ash brick masonry assemblages. The proposed models are validated using the experimental results reported in the previous literature. These models can be used as a quality control tool for fly ash bricks and masonry at the construction site. Moisture content or saturation level of the brick unit at the time of construction is another key factor contributing to the bond strength of masonry. Masonry wall resists both in-plane and out-of-plane forces through the bond between the brick unit and mortar. Absorption of water from mortar by brick alters the development of a mechanical key that establishes the bond strength. The effect of moisture content of bricks, at the time of construction, on shear and tensile bond strength of fly ash brick masonry is investigated. The results of this study
indicate that around 75% saturation level of the brick unit yields the highest values of shear and tensile bond strength of fly ash brick masonry with cement mortar. Adequate pre-wetting of brick units at the time of construction will ensure the desired moisture content and, subsequently, help to achieve a good bond strength. The strength properties of fly ash brick masonry can show a significant variation because of several influencing factors like source and proportion of constituent materials, workmanship, curing condition among others. Quantification of this uncertainty is essential for the reliability-based limit state design of masonry structures. Safety and strength assessment of structures made of fly ash bricks often require modelling the uncertainty of its properties. The present study investigates the variability associated with compressive strength, shear-, split tensile-, and flexure tensile-bond strength of fly ash brick masonry and proposes the most appropriate model for its statistical distribution. Ten probability distributions are considered to conduct the three goodness of fit tests, namely Kolmogorov-Smirnov, Kolmogorov-Smirnov-Lilliefors, and Anderson-Darling tests. The analysis shows that conventionally assumed normal distribution is not suitable for describing the strength properties of fly ash brick masonry as the experimentally obtained strength data is not symmetrical about its mean value. The best-fitted distribution functions that perform well in describing the variability in different strength properties of fly ash brick masonry are recommended. A case study on the seismic risk of a typical reinforced concrete framed building infilled with fly ash masonry is performed considering different probability distribution functions. The results of the case study indicate that the choice of the probability distribution of the random variables influences the seismic risk assessment of structures significantly and consideration of the appropriate distribution function is vital for the precise estimation of seismic ris
Study of Transport and Mechanical Properties of YBCO Composite Superconductor
No full textThe thesis work mainly ascribes the modification on the structural, electric &magnetic transport, and mechanical properties of pristine YBa2Cu3O7−δ superconductor and its composites with carbon-based compound (carbon nanotubes and graphene oxide), manganites, and ferrites. These materials were synthesized by the solid-state reaction route. The modified physical and chemical properties of the materials have been discussed through a weak-link mechanism, order parameter fluctuation, developments of artificial pinning centres, inhomogeneities. Various models are also introduced to verify the experimental data to explore meaningful observations. The above mentioned work has been discussed thoroughly in six different chapters as follows: Chapter 01 gives a brief introduction to superconductors with various phenomena, novel superconducting theories, and their classifications. Moreover, clear descriptions regarding the motivation and objective of the whole thesis work have been presented. Chapter 02 presents a detailed description of the synthesis techniques adopted for the preparation of the pristine as well as composite superconductors followed by the experimental techniques. The experimental techniques are used for the characterization of structural, transport, magnetic and mechanical properties of the pristine and its composite materials. Chapter 03 has two parts. Part 01 describes the structural modifications and variation of properties of YBCO superconductor with the addition of various wt. % of carbon nanotubes (CNTs). Part 02 deals with the effect of CNTs addition on the structural and mechanical properties of YBCO synthesized material. Chapter 04 describes the variation of structural, transport and mechanical properties of (1-x) YBa2Cu3O7-δ + x Graphene Oxide (GO) composite system. Chapter 05 has two parts. Part 01 deals with the variations of superconducting and mechanical properties of YBa2Cu3O7-δ composite thick films with La0.67Sr0.33MnO3 (LSMO). Part 02 describes the variation superconducting parameters along with excess conductivity analysis of CoFe2O4 added YBCO samples. Chapter 06 gives the summary of the thesis work with future scope. The work outlined in the present thesis has been published in international journals
Identification of Spontaneous Heating in Large Coal Stockpiles and Its Protective Measures
No full textMine fire is a major problem faced by industries all over the world. Thousand million tonnes of coal are burnt and lost every year due to coal mine fire. It is concluded from the researches that coal catches fire due to spontaneous combustion i.e. natural and time-dependent phenomena. The propensity of Indian coals to catch fire is said to be between 9 to 12 months. Coal when exposed to air, react with oxygen and gradual self-heating of coal takes place. This interaction of coal with oxygen is an exothermic process, liberating heat. Therefore, there is a gradual accumulation of heat. In the case of the stockpile, a large amount of heat is accumulated as compared to dissipation. Thus, the accumulated heat enhances the coal temperature continuously and reaches to a point where self-heating occurs in a self propellant manner. This point of accumulation is termed as a hotspot and acts as an ignition point in piles. If we are able to know the mechanism of the spontaneous heating and its formation, then steps can be adapted to retard its propagation-cum transmission within the stockpile or in the mine. A huge amount of nature reserves can be saved. This project deals with the study of spontaneous heating liability of coals, and the process of heat generation in coal stockpile. Coal samples are collected from different coalfields in India. The in-situ properties of coal are studied through proximate analysis, crossing point temperature method (C.P.T) and wet oxidation potential (W.O.P) analysis. Numerical simulation of spontaneous heating is done by ANSYS software (Transient Thermal Analysis – T.T.A). The suggestive preventive measures are given on the basis of results obtained from different experiments including Differential thermal analysis and Flammability Test