Deposition and characterization of magnetron sputtered BCC tantalum

The goal of this thesis was to provide scientific and technical research results for developing and characterizing tantalum (Ta) coatings on steel substrates deposited by DC magnetron sputtering. Deposition of tantalum on steel is of special interest for the protection it offers to surfaces, e.g. the surfaces of gun barrels against the erosive wear of hot propellant gases and the mechanical damage caused by the motion of launching projectiles. Electro-plated chromium is presently most commonly used for this purpose; however, it is considered to be carcinogenic in its hexavalent form. Tantalum is being investigated as non-toxic alternative to chromium and also because of its superior protective properties in these extreme environments. DC magnetron sputtering was chosen for this investigation of tantalum coatings on steel substrates because it is a versatile industrial proven process for deposition of metals. Sputter deposited Ta films can have two crystallographic structures: 1) body center cubic (bcc) phase, characterized by high toughness and high ductility and 2) a tetragonal beta phase characterized by brittleness and a tendency to fail under stress. It was found in this work that the bcc Ta coatings on steel can be obtained reliably by either of two methods: 1) depositing Ta on a submicron, stoichiometric TaN seed layer reactively sputtered on unheated steel and 2) depositing Ta directly on steel heated above a critical temperature. For argon sputtering gas this critical temperature was found to be 400°C at a pressure of 5 mtorr. With the heavier krypton gas, this critical temperature is reduced to 350°C. X-ray diffraction (XRD) was used to investigate the structure of tantalum and nitride films, and the composition of the nitride films was measured by nuclear reaction analyses (NRA), which were used to study in detail the enhancement of the bcc phase of Ta on steel. The scratch adhesion tests performed with a diamond hemispherical tip of radius 200 µm under increasing loads revealed high critical load values for failure (\u3e15 N) for the bcc coatings versus the low load values (\u3c9 N) for the beta coatings. The coating deposited on TaN interlayers on sputter-etched steel had better adhesion than those on steel surface without sputter etching. The results for this work have demonstrated that by controlling the various process parameters of dc magnetron sputtering, high quality bcc Ta coatings of multimicron thickness with excellent adhesion to steel can be made. An important contribution of this dissertation is in the enhancing an understanding of this process. The impact of this research will be in a number of fields where superior protective castings are needed. These include military applications, electronic components, chemical processing, and others

Radiative properties of silicon

The objective of this thesis was 1) to study the radiative properties of silicon in the wavelength range of 1 to 20 microns and temperature range of 30 to 1000°C for the development of a multi-wavelength pyrometer 2) to develop a [sic] methodologies for deconvolution of the measured optical properties to yield fundamental optical constants of bulk materials. A novel spectral emissometer has been utilized for measurement of the temperature dependent radiative properties of silicon. The temperature determination capability of the emissometer was tested and verified using a standard thermocouple embedded in a silicon wafer. The temperature measurement accuracy, with the emissometer, was found to be within ± 10°C of the thermocouple temperature for a temperature range of 30 to 300°C. The experimental results presented in this thesis showed that the measurement of high temperature optical properties could be performed reliably with a novel non-contact, real-time approach using the spectral emissometer. The optical properties of n and p-type lightly and heavily doped silicon wafers were investigated. These studies have led us to establish spectral emissometer as a reliable technique for simultaneous measurements of radiative properties and temperature in the 1-20 µm wavelength range

Amniotic fluid index as indicator for pregnancy outcome in late third trimester

Background: Amniotic fluid index is one of the major predictors of pregnancy outcome. Less AFI indicate growth restriction and renal anomalies of fetus, whereas more may indicate fetal GI anomalies, maternal diabetes mellitus, and so forth. Objectives were to establish reference standards for AFI for local population after 34 weeks of pregnancy and to decide an optimal scan interval for AFI estimation in third trimester in low-risk antenatal women. Methods: A prospective estimation of AFI was done in 83 healthy low risk pregnant women from 34 to 40 weeks at weekly intervals. The trend of amniotic fluid volume was studied with advancing gestational age. Statistical analysis was done using SPSS software (Version 16, Chicago, IL). Percentile curves (5th, 50th, and 95th centiles) were constructed for comparison with other studies. Cohen’s d coefficient was used to examine the magnitude of change at different time intervals. Results: Starting from 34 weeks till 40 weeks, 83 ultrasound measurements were available. The mean (standard deviation) of AFI values (in cms) were 34W:14.59(1.79), 35W: 14.25 (1.57), 36W: 13.17 (1.56), 37W: 12.48 (1.52), 38W: 12.2 (1.7), and 39W: 11.37 (1.71). The5th percentile cut-off was 8.7 cm at 40 weeks. There was a gradual decline of AFI values as the gestational age approached term. Significant drop in AFI was noted at two-week intervals. Conclusions: Appreciable changes occurred in AFI values as gestation advanced by two weeks. Hence, it is recommended to follow up low risk antenatal women every two weeks after 34 weeks of pregnancy

Inhibitive action of Bridelia retusa leaves extract on corrosion of mild steel in acidic media

Extract of Bridelia retusa leaves was investigated as corrosion inhibitor of mild steel in 1 N H2SO4 using conventional weight loss, electrochemical polarizations, electrochemical impedance spectroscopy and scanning electron microscopic studies. The weight loss results showed that the extract of Bridelia retusa leaves is excellent corrosion inhibitor and electrochemical polarizations data revealed the mixed mode of inhibition. While the results of electrochemical impedance spectroscopy have shown that the change in the impedance parameters, charge transfer resistance and double layer capacitance, with the change in concentration of the extract is due to the adsorption of active molecules leading to the formation of a protective layer on the surface of mild steel. Scanning electron microscopic studies provided the confirmatory evidence of improved surface condition, due to the adsorption, for the corrosion protection

Fetomaternal outcome in patients of decreased fetal movements after thirty-four weeks of gestation

Background: Maternal perception of decreased fetal movements is a cause of concern and common reason for visits to the antenatal clinic or delivery room. Several studies have shown that a reduction or cessation of fetal movements may result in poor pregnancy outcome and magnified increased risks of serious perinatal morbidity and mortality. Aim and objectives were to determine the correlation between decreased daily fetal movement counts, NST, USG and Colour Doppler with maternal and fetal outcome. Methods: This study was a prospective observational study, conducted in department of obstetrics and gynecology at Surat municipal institute medical education and research medical college from January 2020 to June 2021. Results: The study group consisted of 83 patients between 34 to 40 weeks of gestation with Decreased fetal movements. 60.24% patients belonged to age group between 21-25 years. 60.22% patients were multigravida.87.95% patients were full term, 59.09% patients presented between 12-24 hours of duration with complain of decreased fetal movements. In view of NST results, 72.29% patients had reactive-NST. In ultrasonography, 27.10% had AFI <5 cm and 72.90% had AFI >5 cm & all patients had normal color Doppler study.  60 patients had induced labor. 68.67% patients delivered vaginally. 42.10% of vaginal deliveries, 80% of Instrumental vaginal deliveries and 75% of LSCS had Meconium-stained liquor. 81.92% babies had APGAR score of >7 at birth. 84.33% had birth weight more than 2.5 kg 68.18% babies were admitted in NICU due to Meconium aspiration syndrome, followed by respiratory distress syndrome in 18.18% and birth asphyxia in 13.63% babies. Conclusions: Decreased fetal movement is a frequently occurring antenatal presentation, associated with poor perinatal outcomes. Daily fetal movement counts are very effective, cheap and reliable method to diagnose fetal compromise early. Methods like NST, USG and Colour Doppler study are helpful in the identification of causes and timely management of the patient with decreased fetal movements and helpful to diagnose the fetus at risk and their timely delivery

Crop Diversification an Effective Strategy for Sustainable Agriculture Development

Sustainable agricultural practices involve a variety of approaches. The most important approached for sustainable agriculture development is crop diversification. It allowing the farmers to employ biological cycles to minimize inputs, conserve the resource base, maximize yields and also reduce the risk due to ecological and environmental factors. It serves as an important opportunity to augment income and employment generation for rural communities. Crop diversification promotes the interaction of beneficial soil bacteria, interrupts the disease cycle, and reduces the quantity of weeds. Crop diversification boosts land-use efficiency and crop output by improving the physical and chemical qualities of soil. Crop diversification shows a lot of scope to alleviating the problems such as resurgence of insects-pests and weeds, soil degradation, environmental pollution, soil salinity, decline farm profit and climate change. Crop diversification through crop intensification system enhanced the net returns, B:C ratio, and overall system productivity of a farm. In order to achieve the benefits of crop diversification farmers are shifting from low value low yielding crops to high value high yielding crops. Thus, crop diversification has the sound capacity for achieving the goal of nutritional security, income growth, food security, employment generation and sustainable agriculture development

Myosin5a tail associates directly with Rab3A-containing compartments in neurons

Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of American Society for Biochemistry and Molecular Biology. The definitive version was published in Journal of Biological Chemistry, 286 (2011): 14352-14361, doi:10.1074/jbc.M110.187286.Myosin-Va (Myo5a) is a motor protein associated with synaptic vesicles (SVs) but the mechanism by which it interacts has not yet been identified. A potential class of binding partners are Rab GTPases and Rab3A is known to associate with SVs and is involved in SV trafficking. We performed experiments to determine whether Rab3A interacts with Myo5a and whether it is required for transport of neuronal vesicles. In vitro motility assays performed with axoplasm from the squid giant axon showed a requirement for a Rab GTPase in Myo5a-dependent vesicle transport. Furthermore, mouse recombinant Myo5a tail revealed that it associated with Rab3A in rat brain synaptosomal preparations in vitro and the association was confirmed by immunofluorescence imaging of primary neurons isolated from the frontal cortex of mouse brains. Synaptosomal Rab3A was retained on recombinant GST-tagged Myo5a tail affinity columns in a GTP-dependent manner. Finally, the direct interaction of Myo5a and Rab3A was determined by sedimentation v e l o c i t y analytical ultracentrifugation using recombinant mouse Myo5a tail and human Rab3A. When both proteins were incubated in the presence of 1 mM GTPγS, Myo5a tail and Rab3A formed a complex and a direct interaction was observed. Further analysis revealed that GTP-bound Rab3A interacts with both the monomeric and dimeric species of the Myo5a tail. However, the interaction between Myo5a tail and nucleotidefree Rab3A did not occur. Thus, our results show that Myo5a and Rab3A are direct binding partners and interact on SVs and that the Myo5a/Rab3A complex is involved in transport of neuronal vesicles

Health, education, and social care provision after diagnosis of childhood visual disability

Aim: To investigate the health, education, and social care provision for children newly diagnosed with visual disability.Method: This was a national prospective study, the British Childhood Visual Impairment and Blindness Study 2 (BCVIS2), ascertaining new diagnoses of visual impairment or severe visual impairment and blindness (SVIBL), or equivalent vi-sion. Data collection was performed by managing clinicians up to 1-year follow-up, and included health and developmental needs, and health, education, and social care provision.Results: BCVIS2 identified 784 children newly diagnosed with visual impairment/SVIBL (313 with visual impairment, 471 with SVIBL). Most children had associated systemic disorders (559 [71%], 167 [54%] with visual impairment, and 392 [84%] with SVIBL). Care from multidisciplinary teams was provided for 549 children (70%). Two-thirds (515) had not received an Education, Health, and Care Plan (EHCP). Fewer children with visual impairment had seen a specialist teacher (SVIBL 35%, visual impairment 28%, χ2p < 0.001), or had an EHCP (11% vs 7%, χ2p < 0 . 01).Interpretation: Families need additional support from managing clinicians to access recommended complex interventions such as the use of multidisciplinary teams and educational support. This need is pressing, as the population of children with visual impairment/SVIBL is expected to grow in size and complexity.This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited

The unfinished agenda of communicable diseases among children and adolescents before the COVID-19 pandemic, 1990-2019: a systematic analysis of the Global Burden of Disease Study 2019

BACKGROUND: Communicable disease control has long been a focus of global health policy. There have been substantial reductions in the burden and mortality of communicable diseases among children younger than 5 years, but we know less about this burden in older children and adolescents, and it is unclear whether current programmes and policies remain aligned with targets for intervention. This knowledge is especially important for policy and programmes in the context of the COVID-19 pandemic. We aimed to use the Global Burden of Disease (GBD) Study 2019 to systematically characterise the burden of communicable diseases across childhood and adolescence. METHODS: In this systematic analysis of the GBD study from 1990 to 2019, all communicable diseases and their manifestations as modelled within GBD 2019 were included, categorised as 16 subgroups of common diseases or presentations. Data were reported for absolute count, prevalence, and incidence across measures of cause-specific mortality (deaths and years of life lost), disability (years lived with disability [YLDs]), and disease burden (disability-adjusted life-years [DALYs]) for children and adolescents aged 0-24 years. Data were reported across the Socio-demographic Index (SDI) and across time (1990-2019), and for 204 countries and territories. For HIV, we reported the mortality-to-incidence ratio (MIR) as a measure of health system performance. FINDINGS: In 2019, there were 3·0 million deaths and 30·0 million years of healthy life lost to disability (as measured by YLDs), corresponding to 288·4 million DALYs from communicable diseases among children and adolescents globally (57·3% of total communicable disease burden across all ages). Over time, there has been a shift in communicable disease burden from young children to older children and adolescents (largely driven by the considerable reductions in children younger than 5 years and slower progress elsewhere), although children younger than 5 years still accounted for most of the communicable disease burden in 2019. Disease burden and mortality were predominantly in low-SDI settings, with high and high-middle SDI settings also having an appreciable burden of communicable disease morbidity (4·0 million YLDs in 2019 alone). Three cause groups (enteric infections, lower-respiratory-tract infections, and malaria) accounted for 59·8% of the global communicable disease burden in children and adolescents, with tuberculosis and HIV both emerging as important causes during adolescence. HIV was the only cause for which disease burden increased over time, particularly in children and adolescents older than 5 years, and especially in females. Excess MIRs for HIV were observed for males aged 15-19 years in low-SDI settings. INTERPRETATION: Our analysis supports continued policy focus on enteric infections and lower-respiratory-tract infections, with orientation to children younger than 5 years in settings of low socioeconomic development. However, efforts should also be targeted to other conditions, particularly HIV, given its increased burden in older children and adolescents. Older children and adolescents also experience a large burden of communicable disease, further highlighting the need for efforts to extend beyond the first 5 years of life. Our analysis also identified substantial morbidity caused by communicable diseases affecting child and adolescent health across the world. FUNDING: The Australian National Health and Medical Research Council Centre for Research Excellence for Driving Investment in Global Adolescent Health and the Bill & Melinda Gates Foundation

Association of respiratory symptoms and lung function with occupation in the multinational Burden of Obstructive Lung Disease (BOLD) study

Background Chronic obstructive pulmonary disease has been associated with exposures in the workplace. We aimed to assess the association of respiratory symptoms and lung function with occupation in the Burden of Obstructive Lung Disease study. Methods We analysed cross-sectional data from 28 823 adults (≥40 years) in 34 countries. We considered 11 occupations and grouped them by likelihood of exposure to organic dusts, inorganic dusts and fumes. The association of chronic cough, chronic phlegm, wheeze, dyspnoea, forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1)/FVC with occupation was assessed, per study site, using multivariable regression. These estimates were then meta-analysed. Sensitivity analyses explored differences between sexes and gross national income. Results Overall, working in settings with potentially high exposure to dusts or fumes was associated with respiratory symptoms but not lung function differences. The most common occupation was farming. Compared to people not working in any of the 11 considered occupations, those who were farmers for ≥20 years were more likely to have chronic cough (OR 1.52, 95% CI 1.19–1.94), wheeze (OR 1.37, 95% CI 1.16–1.63) and dyspnoea (OR 1.83, 95% CI 1.53–2.20), but not lower FVC (β=0.02 L, 95% CI −0.02–0.06 L) or lower FEV1/FVC (β=0.04%, 95% CI −0.49–0.58%). Some findings differed by sex and gross national income. Conclusion At a population level, the occupational exposures considered in this study do not appear to be major determinants of differences in lung function, although they are associated with more respiratory symptoms. Because not all work settings were included in this study, respiratory surveillance should still be encouraged among high-risk dusty and fume job workers, especially in low- and middle-income countries.publishedVersio