Effect of surface roughness on heat transfer and fluid flow characteristics at low Reynolds Numbers in small diameter tubes

The effect surface roughness on pressure drop and heat transfer in circular tubes has been extensively studied in literature. The pioneering work of Nikuradse (1933) established the sand grain roughness as a major parameter in defining the friction factor during laminar and turbulent flows. Recent studies have indicated a transition to turbulent flows at Reynolds number values much below 2300 during single-phase flow in channels with small hydraulic diameters. In the present work, a detailed experimental study is undertaken to investigate the roughness effects in small diameter tubes. The roughness of the inside tube surface is changed by acid treatment. Two tubes of 1.067 mm and 0.62 mm inner diameter are treated with acid solutions to provide three different roughness values for each tube. The Reynolds number ranges for the tests are 500-2600 for 1.062mm tube and 900-3000 for 0.62mm tube. The results indicated no significant effect of surface roughness on 1.067mm tube for both pressure drop and heat transfer tests. In case of 0.62mm tube it was seen that with reduction in relative surface roughness values, both Nusselt number and pressure drop values reduced. Smoother tube produced lower values of Nusselt number and pressure drop than rougher tube

Performance evaluation of duct-mounted relative humidity sensors used in building HVAC applications

Relative humidity sensors are common components in building heating, ventilating, and air-conditioning (HVAC) systems, and their performance can significantly impact energy use in these systems. A study was undertaken to test and evaluate the most commonly used relative humidity sensors in building HVAC systems, namely the capacitive and resistive types. Sensor models from six different manufacturers were used for testing. Three sensors of each model for a total of 18 sensors were tested, nine of them were capacitive-type sensors and nine were resistive-type sensors. The performance of these sensors was determined by subjecting the sensors to a series of tests that included accuracy, linearity, repeatability, hysteresis, ageing, response time and stress. For each test, a detailed method of test was developed and peer reviewed.;The accuracy test results showed that two of the six humidity sensor models were within manufacturer specified accuracy, while a third sensor model did not met the manufactured specified accuracy at any humidity level tested, and finally, the remaining three sensor models, met the manufacturer specified accuracy for only part of the humidity range. Further, the repeatability of all sensors models at 50% RH and 15, 25, and 35°C was within 1.5% RH. The maximum hysteresis for all sensors was less than 3.2% for all humidities and temperatures. And finally, at 25°C, Model-B sensor had the largest nonlinearity of -3.8% while Model-C sensor had the least nonlinearity of 0.0%.;The accuracy results after the ageing test showed that only one sensor out of twelve sensors was unaffected both before and after the ageing test, while four sensors out of the remaining eleven sensors were unaffected after the ageing test.;The response time test results showed that the average response times of relative humidity sensors ranged between 7 sec and 96 sec.;The accuracy test results after the stress test showed that two out of six sensors remain unaffected at all relative humidities, while two out of the remaining four sensor models were affected at any relative humidities evaluated. The remaining two sensor models failed after the stress test

Screening of Rhizobacteria for their plant growth promotion abilities and their interaction with Rhizobium of Mung bean

Phosphorus deficiency is a major constraint for crop production. The beneficial microorganisms in the soil convert insoluble phosphorus into soluble form for plant growth and also prevents their leaching in to water bodies. In present investigation seventy two (72) rhizobacterial isolates were obtained from Mungbean rhizospheric soil on King’s B medium, from various locations near Jodhpur. All the isolates were screened for their ability to solubilize insoluble phosphate on Pikovskaya’s medium, nitrogen fixation and auxin like substance production. Four isolates were able to solubilize phosphate ranging from 42.69 ?g TCP/ml to 90.10 ?g TCP/ml. Total fifty eight (80.55%) isolates out of seventy two rhizobacteria were able to fix atmospheric nitrogen in vitro. Rhizobacterial isolates that were able to fix environmental nitrogen and solubilize phosphate were screened for auxin like substance production. Two isolates were able to produce auxin like substances at lower amount. Among all the rhizobacterial isolates screened for their influence on rhizobial growth in vitro, twenty three (31.94%) isolates stimulated the growth of Mung bean Rhizobium. The diameter of zone of stimulation varied from 6.0 mm (MrbIV 14) to 16.5 mm (MrbII 05 and MrbIII 16) and maximum stimulation was shown by MrbIII 10 (17.5 mm). However, thirty two (44.44%) isolates were neutral to the growth of Mung bean Rhizobium

Dysembryoplastic neuropithelial tumor: a rare case report

Dysembryoplastic neuropithelial tumor (DNET) is a rare recently described, benign glioneural tumor frequently associated with intractable seizures in children and young adults which is important to recognise clinically and radiologically as it is surgically curable without need for adjuvant chemoradiotherapy. We hereby present a case report of a 10year old male child who presented with intractable seizures and right parietal space occupying lesion which was diagnosed DNET radiologically, treated by microsurgical excision and confirmed histopathologically as DNET, thus emphasising multidisciplinary role in management of this rare entity

A novel approach of intra-operative shape acquisition of the tibio-femoral joints using 3D laser scanning for computer assisted orthopaedic surgery

Background: Image registration (IR) is an important process of developing a spatial relationship between pre - operative data and physical patient in the operation theatre. Current IR techniques for Computer Assisted Orthopaedic Surgery (CAOS) are time consuming and costly. There is a need to automate and accelerate this process. Methods: Bespoke quick, cost effective, contactless and automated 3D laser scanning techniques based on the DAVID Laserscanner method were designed. 10 cadaveric knee joints were intra - operatively laser scanned and were registered with the pre - operative MRI scans. The results are supported with a concurrent validity study. Results: The average absolute errors between scan models were systematically less than 1mm. Errors on femoral surfaces were higher than tibial surfaces. Additionally, scans acquired through the large exposure produced higher errors than the smaller exposure. Conclusion: This study has provided proof of concept for a novel automated shape acquisition and registration technique for CAOS

Epoxy-based Light Weight Gamma Ray Shielding Materials

274-282Lightweight epoxy-based X-ray /gamma-ray shielding materials were synthesized by blending epoxy resin with the different weight percent of lead oxide, bismuth oxide, and tungsten oxide powders. The synthesized composites were characterized using FTIR, elemental analyzer, and X-ray radiography for their chemical structure, elemental composition, and filler distribution. The photon interaction parameters such as linear/mass attenuation coefficient, attenuation percentage, and half value layer were determined for all composites at photon energies 59.5, 364, and 661.7 keV. The measured mass attenuation coefficients of epoxy composites matched well with the obtained from XCOM. Moreover, the shielding effectiveness of the composites was analyzed by the half-value layer and heaviness of the composites and was compared with conventional shielding materials (concrete, lead, and steel)

Correlation between Maternal Mid Upper Arm Circumference and Neonatal Birth Weight: A Case-control Study

Introduction: Birth weight is the best marker of optimal foetal growth and development. Apart from being an important determinant of newborn survival, Low Birth Weight (LBW) also indicates nutritional deprivation and poor health of the mother during and before pregnancy. On the other hand, Maternal nutrition and anthropometry also affect infant’s birth weight. Aim: To find out the correlation of maternal Mid Upper Arm Circumference (MUAC) and neonatal birth weight. Materials and Methods: This case-control study was conducted at Datta Meghe Medical College and Shalinitai Meghe Hospital and Research Centre (tertiary care hospital), Nagpur, Maharashtra, India, from September 2021 to February 2022. Convenient sampling method was used to select cases and control. All the mothers who had delivered full term live singleton new born with birth weight <2.5 kg were selected as a case and mothers who had delivered singleton new born babies ≥2.5 kg were selected as a control. There was a total of 100 mother-infant dyads with 50 pairs having infant with LBW (cases) and the rest 50 with infants having normal birth weight (controls). Data was collected on the socio-demographic status of the mothers using a predesigned questionnaire along with their weight (from record), maternal MUAC measurement, and birth weight of their babies. Analysis was done using Statistical Package for Social Sciences (SPSS) version 16.0. Results: Mean age of cases was 24.48±2.757 years and that of controls was 24.52±2.255 years. Mean birth weight was 2206±200.9 gm for cases and 2934±305.79 gm for the control group. Maternal MUAC was ≤23 cm in 52% of cases and only 16% in controls (OR- 5.69, CI: 2.23-13.74, p-value=0.001). A linear correlation was found between maternal MUAC and birth weight (r-value=0.3376, p-value=0.001). Conclusion: As there was a positive correlation between maternal MUAC ≤23 cm and LBW babies, maternal MUAC can be used as a predictor of LBW, and hence, measurement of maternal MUAC should be included during antenatal check-ups

Global age-sex-specific fertility, mortality, healthy life expectancy (HALE), and population estimates in 204 countries and territories, 1950-2019 : a comprehensive demographic analysis for the Global Burden of Disease Study 2019

Background: Accurate and up-to-date assessment of demographic metrics is crucial for understanding a wide range of social, economic, and public health issues that affect populations worldwide. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 produced updated and comprehensive demographic assessments of the key indicators of fertility, mortality, migration, and population for 204 countries and territories and selected subnational locations from 1950 to 2019. Methods: 8078 country-years of vital registration and sample registration data, 938 surveys, 349 censuses, and 238 other sources were identified and used to estimate age-specific fertility. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate age-specific fertility rates for 5-year age groups between ages 15 and 49 years. With extensions to age groups 10–14 and 50–54 years, the total fertility rate (TFR) was then aggregated using the estimated age-specific fertility between ages 10 and 54 years. 7417 sources were used for under-5 mortality estimation and 7355 for adult mortality. ST-GPR was used to synthesise data sources after correction for known biases. Adult mortality was measured as the probability of death between ages 15 and 60 years based on vital registration, sample registration, and sibling histories, and was also estimated using ST-GPR. HIV-free life tables were then estimated using estimates of under-5 and adult mortality rates using a relational model life table system created for GBD, which closely tracks observed age-specific mortality rates from complete vital registration when available. Independent estimates of HIV-specific mortality generated by an epidemiological analysis of HIV prevalence surveys and antenatal clinic serosurveillance and other sources were incorporated into the estimates in countries with large epidemics. Annual and single-year age estimates of net migration and population for each country and territory were generated using a Bayesian hierarchical cohort component model that analysed estimated age-specific fertility and mortality rates along with 1250 censuses and 747 population registry years. We classified location-years into seven categories on the basis of the natural rate of increase in population (calculated by subtracting the crude death rate from the crude birth rate) and the net migration rate. We computed healthy life expectancy (HALE) using years lived with disability (YLDs) per capita, life tables, and standard demographic methods. Uncertainty was propagated throughout the demographic estimation process, including fertility, mortality, and population, with 1000 draw-level estimates produced for each metric. Findings: The global TFR decreased from 2·72 (95% uncertainty interval [UI] 2·66–2·79) in 2000 to 2·31 (2·17–2·46) in 2019. Global annual livebirths increased from 134·5 million (131·5–137·8) in 2000 to a peak of 139·6 million (133·0–146·9) in 2016. Global livebirths then declined to 135·3 million (127·2–144·1) in 2019. Of the 204 countries and territories included in this study, in 2019, 102 had a TFR lower than 2·1, which is considered a good approximation of replacement-level fertility. All countries in sub-Saharan Africa had TFRs above replacement level in 2019 and accounted for 27·1% (95% UI 26·4–27·8) of global livebirths. Global life expectancy at birth increased from 67·2 years (95% UI 66·8–67·6) in 2000 to 73·5 years (72·8–74·3) in 2019. The total number of deaths increased from 50·7 million (49·5–51·9) in 2000 to 56·5 million (53·7–59·2) in 2019. Under-5 deaths declined from 9·6 million (9·1–10·3) in 2000 to 5·0 million (4·3–6·0) in 2019. Global population increased by 25·7%, from 6·2 billion (6·0–6·3) in 2000 to 7·7 billion (7·5–8·0) in 2019. In 2019, 34 countries had negative natural rates of increase; in 17 of these, the population declined because immigration was not sufficient to counteract the negative rate of decline. Globally, HALE increased from 58·6 years (56·1–60·8) in 2000 to 63·5 years (60·8–66·1) in 2019. HALE increased in 202 of 204 countries and territories between 2000 and 2019

Global burden of 369 diseases and injuries in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

Background: In an era of shifting global agendas and expanded emphasis on non-communicable diseases and injuries along with communicable diseases, sound evidence on trends by cause at the national level is essential. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) provides a systematic scientific assessment of published, publicly available, and contributed data on incidence, prevalence, and mortality for a mutually exclusive and collectively exhaustive list of diseases and injuries. Methods: GBD estimates incidence, prevalence, mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) due to 369 diseases and injuries, for two sexes, and for 204 countries and territories. Input data were extracted from censuses, household surveys, civil registration and vital statistics, disease registries, health service use, air pollution monitors, satellite imaging, disease notifications, and other sources. Cause-specific death rates and cause fractions were calculated using the Cause of Death Ensemble model and spatiotemporal Gaussian process regression. Cause-specific deaths were adjusted to match the total all-cause deaths calculated as part of the GBD population, fertility, and mortality estimates. Deaths were multiplied by standard life expectancy at each age to calculate YLLs. A Bayesian meta-regression modelling tool, DisMod-MR 2.1, was used to ensure consistency between incidence, prevalence, remission, excess mortality, and cause-specific mortality for most causes. Prevalence estimates were multiplied by disability weights for mutually exclusive sequelae of diseases and injuries to calculate YLDs. We considered results in the context of the Socio-demographic Index (SDI), a composite indicator of income per capita, years of schooling, and fertility rate in females younger than 25 years. Uncertainty intervals (UIs) were generated for every metric using the 25th and 975th ordered 1000 draw values of the posterior distribution. Findings: Global health has steadily improved over the past 30 years as measured by age-standardised DALY rates. After taking into account population growth and ageing, the absolute number of DALYs has remained stable. Since 2010, the pace of decline in global age-standardised DALY rates has accelerated in age groups younger than 50 years compared with the 1990–2010 time period, with the greatest annualised rate of decline occurring in the 0–9-year age group. Six infectious diseases were among the top ten causes of DALYs in children younger than 10 years in 2019: lower respiratory infections (ranked second), diarrhoeal diseases (third), malaria (fifth), meningitis (sixth), whooping cough (ninth), and sexually transmitted infections (which, in this age group, is fully accounted for by congenital syphilis; ranked tenth). In adolescents aged 10–24 years, three injury causes were among the top causes of DALYs: road injuries (ranked first), self-harm (third), and interpersonal violence (fifth). Five of the causes that were in the top ten for ages 10–24 years were also in the top ten in the 25–49-year age group: road injuries (ranked first), HIV/AIDS (second), low back pain (fourth), headache disorders (fifth), and depressive disorders (sixth). In 2019, ischaemic heart disease and stroke were the top-ranked causes of DALYs in both the 50–74-year and 75-years-and-older age groups. Since 1990, there has been a marked shift towards a greater proportion of burden due to YLDs from non-communicable diseases and injuries. In 2019, there were 11 countries where non-communicable disease and injury YLDs constituted more than half of all disease burden. Decreases in age-standardised DALY rates have accelerated over the past decade in countries at the lower end of the SDI range, while improvements have started to stagnate or even reverse in countries with higher SDI. Interpretation: As disability becomes an increasingly large component of disease burden and a larger component of health expenditure, greater research and developm nt investment is needed to identify new, more effective intervention strategies. With a rapidly ageing global population, the demands on health services to deal with disabling outcomes, which increase with age, will require policy makers to anticipate these changes. The mix of universal and more geographically specific influences on health reinforces the need for regular reporting on population health in detail and by underlying cause to help decision makers to identify success stories of disease control to emulate, as well as opportunities to improve. Funding: Bill & Melinda Gates Foundation. © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licens