Mechanical Properties of Hot Rolled Ribbed and Plain Steel Rods

This study focuses on microstructure and mechanical behaviour of 3PS (Semi-killed mild steel) hot rolled ribbed and plain carbon steel. 3PS billet steel samples and hot rolled ribbed and plain steel rods of different heat numbers and profiles were characterized for its chemical composition, microstructure, and tensile behaviour. The composition analysis of 5 (five) 3PS billet samples shows that there was no appreciable variation in chemical composition of the hot-rolled plain and ribbed steel rods. The microstructures of as-received steel billet (3PS) examination revealed large grains of ferrite and pearlite while those of hot-rolled 3 PS mild steel samples of different heat numbers contain smaller grains of ferrite and some amount of pearlite. The results also indicated that yield and ultimate tensile strength reach maximum values (492 and 361 N/mm2) at 0.31% elongation for heat number 43 while maximum values for heat number 56 (478 and 362 N/mm2) at 0.33 % respectively. The ribbed steel rod of the same diameter as plain steel exhibit slightly better mechanical properties with higher values of yield and ultimate tensile strength. There is consistency in the chemical composition of the as-received billet and the hot rolled products.

Connection Recipes: Exploring Optimum Connection Practices through a Data-Driven Approach

Although numerous studies have investigated how shocks and vibrations contribute to bottomhole assembly (BHA) failures during hole-making, very few have explicitly focused on shock and vibrational behaviors during drillpipe connections. This study adopts a data-driven approach to explore various connection practices and their associated shocks and vibrations, aiming to propose optimum "connection recipes" that minimize negative drillstring impacts during connections. This study utilized data from surface sensors as well as downhole accelerometers and gyroscopes installed both at a downhole sub and the bit. In total, 520 connections from 5 lateral sections were studied. Several quality checks and corrections were performed to ensure synchronization between surface and downhole data. The analyses focused on two connection phases specifically: going off-bottom and going back to bottom. The presence of stick-slip events and high magnitudes of both maximum and root mean squared (RMS) radial accelerations were examined together with the associated surface drilling parameters. Various visualization approaches were performed to help demonstrate the vibration and shock behaviors resulting from different going off-bottom and going back to bottom practices. The analyses showed that restarting surface rotational speed at low values (≤ 40 RPM) risks inducing stick-slip events when going back to bottom. When the surface RPM was increased sufficiently, a notable reduction in RMS radial acceleration was observed. Maximum radial acceleration magnitude was highest before WOB application, which could be mitigated by immediate WOB re-application. Appreciable variation in the maximum radial acceleration was apparent when restarting at low (≤ 15 klbf) WOB values. When going off-bottom, drilling off should be accompanied by a reduction in the surface rotational speed to avoid a jump in the maximum radial acceleration values. This work provides suggestions on how to execute better connections. Since the impacts of shocks and vibrations during connections have previously been largely overlooked, this study fills a knowledge gap to help establish better practices and automation routines to improve the lifespan of the bit and downhole tools.

RNA virome diversity and Wolbachia infection in individual Drosophila simulans flies

The endosymbiont bacterium Wolbachia is associated with multiple mutualistic effects on insect biology, including nutritional and antiviral properties. Wolbachia naturally occurs in Drosophila fly species, providing an operational model host to study how virome composition may be impacted by its presence. Drosophila simulans populations can carry a variety of Wolbachia strains. In particular, the wAu strain of Wolbachia has been associated with strong antiviral protection under experimental conditions. We used D. simulans sampled from the Perth Hills, Western Australia, to investigate the potential virus protective effect of the wAu strain on individual wild-caught flies. Our data revealed no appreciable variation in virus composition and abundance between Wolbachia infected/uninfected individuals associated with the presence/absence of wAu. However, it remains unclear whether wAu might impact viral infection and host survival by increasing tolerance rather than inducing complete resistance. These data also provide new insights into the natural virome diversity of D. simulans. Despite the small number of individuals sampled, we identified a repertoire of RNA viruses, including Nora virus, Galbut virus, Chaq virus, Thika virus and La Jolla virus, that have been identified in other Drosophila species. In addition, we identified five novel viruses from the families Reoviridae, Tombusviridae, Mitoviridae and Bunyaviridae. Overall, this study highlights the complex interaction between Wolbachia and RNA virus infections and provides a baseline description of the natural virome of D. simulans.

A Comparison of Five Epidemiological Models for Transmission of SARS-CoV-2 in India

BackgroundMany popular disease transmission models have helped nations respond to the COVID-19 pandemic by informing decisions about pandemic planning, resource allocation, implementation of social distancing measures and other non-pharmaceutical interventions. We study how five epidemiological models forecast and assess the course of the pandemic in India: a baseline model, an extended SIR (eSIR) model, two extended SEIR (SAPHIRE and SEIR-fansy) models, and a semi-mechanistic Bayesian hierarchical model (ICM). MethodsUsing COVID-19 data for India from March 15 to June 18 to train the models, we generate predictions from each of the five models from June 19 to July 18. To compare prediction accuracy with respect to reported cumulative and active case counts and cumulative death counts, we compute the symmetric mean absolute prediction error (SMAPE) for each of the five models. ResultsFor active case counts, SMAPE values are 0.72 (SEIR-fansy) and 33.83 (eSIR). For cumulative case counts, SMAPE values are 1.76 (baseline) 23. (eSIR), 2.07 (SAPHIRE) and 3.20 (SEIR-fansy). For cumulative death counts, the SMAPE values are 7.13 (SEIR-fansy) and 26.30 (eSIR). For cumulative cases and deaths, we compute Pearson’s and Lin’s correlation coefficients to investigate how well the projected and observed reported COVID-counts agree. Three models (SAPHIRE, SEIR-fansy and ICM) return total (sum of reported and unreported) counts as well. We compute underreporting factors as of June 30 and note that the SEIR-fansy model reports the highest underreporting factor for active cases (6.10) and cumulative deaths (3.62), while the SAPHIRE model reports the highest underreporting factor for cumulative cases (27.79).ConclusionsIn this comparative paper we describe five different models used to study full disease transmission of the SARS-Cov-2 disease transmission in India. While simulation studies are the only gold standard way to compare the accuracy of the models, here we were uniquely poised to compare the projected case-counts against observed data on a test period. Prediction of daily active number of cases does show appreciable variation across models. The largest variability across models is observed in predicting the “total” number of infections including reported and unreported cases. The degree of under-reporting has been a major concern in India.

Variation in growth performance of pure and crossed meat type chickens

Genetic variation from a combination of four breeds of chickens (Anak Titan, Alpha, Giriraja and Normal indigenous chickens) were examined for importance of sire, dam, season and sex on growth traits using a Mixed-model Least-Squares and Maximum LIkelihood computer program. The results show that sire and dam genotypes significantly (P<0.05) affected growth. Anak Titan cocks and hens performed best in body weight (BW) with values ranging from 38.45±0.74g and 40.21±0.66g at day old to 1135.93 35.67g and 953.38 35.38g at week 12 respectively. Normal indigenous and Alpha improved indigenous performed better in linear body parameters. Genetic correlation coefficients among parameters for all the breeds were generally high. Positive estimates ranged from 0.15 for breast girth (BG) and keel length (KL) at week four to 0.99 for BG-KL at week tweve while negative values ranged from -0.783 for body weight (BW) and wing length (WL) at week four to -0.99 for BW-BG at week twelve. Heritability estimates for body weight ranged from 0.14 at week one to 0.63 at week four. It can be concluded that appreciable variation exists for growth traits among the strains of chickens. Such variations can be utilized for improvement in the present emvironment.

Water–energy nexus for estuarine systems with seasonal salinity variations: a thermodynamic feasibility analysis of reverse osmosis (RO)–pressure retarded osmosis (PRO) combinations

The underlying philosophy of pressure retarded osmosis (PRO)–reverse osmosis (RO) hybrid technology is the assumption of the availability of ‘fresh’ water for the purpose, which gets severely affected once the fresh-water streams undergo seasonal salinity variations. In the present article, the authors have tried to understand the overall feasibility of PRO-RO combination in such estuarine systems with appreciable variation of seasonal salinity. The article first discusses the feasibility of pretreating the feed of PRO using RO and later understanding the feasibility of PRO as supplemental technology to existing RO units. It was found that pretreating the PRO feed in such estuarine systems was energetically infeasible. However, PRO as supporting technology was found to produce energy of around 0.0994 kWh for 50% recovery. It was also concluded that with a fraction of RO permeate used for PRO, energy savings increase for estuarine systems with seasonal salinity variations.

The genomic architecture of flowering time varies across space and time in Mimulus guttatus

The degree to which genomic architecture varies across space and time is central to the evolution of genomes in response to natural selection. Bulked-segregant mapping combined with pooled sequencing provides an efficient method to estimate the effect of genetic variants on quantitative traits. We develop a novel likelihood framework to identify segregating variation within multiple populations and generations while accommodating estimation error on a sample- and SNP-specific basis. We use this method to map loci for flowering time within natural populations of Mimulus guttatus, collecting the early and late flowering plants from each of three neighboring populations and two consecutive generations. We find appreciable variation in genetic effects on flowering time across both time and space; the greatest differences evident between populations. Structural variants, such as inversions, and genes from multiple flowering time pathways exhibit the strongest associations with flowering time. It is also clear that genotype-by-environment interactions are an important influence on flowering time variation.

Mitochondrial DNA hypervariable region 1 diversity in Nigerian goats

SummaryGoats make up the largest group of ruminant livestock in Nigeria and are strategic in bridging animal protein supply gap and improving the economy of rural households. The hypervariable region 1 (HVR1) of the caprine mitochondrial genome was investigated to better understand genetic diversity important for improving selection for animal breeding and conservation programs. We sequenced and analysed the mitochondrial DNA (mtDNA) HVR1 in 291 unrelated indigenous Nigerian goats (West African Dwarf (WAD), Red Sokoto (RSO) and Sahel (SAH)), randomly sampled from around the country, and compared them with the HVR1 sequences of 336 Indian goats and 12 other sequences in five different species in the genusCapra(C. falconeri, C. ibex nubiana, C. aegagrus, C. cylindricornisandC. sibirica). A total of 139 polymorphic sites from 291 individuals were captured in 204 haplotypes. Within and among population variations were 77.25 and 22.74 percent, respectively. Nigerian goats showed high genetic diversity (0.87) and high FST values, and separate from Indian goats and other wild species. Haplogroups in WAD separates it from RSO and SAH concomitant with a different demographic history. Clear genetic structure was found among Nigerian goat breeds with appreciable variation in mtDNA HVR1 region. This study grouped Nigerian goat breeds into two major groups suggesting two different demographic origins for Northern and Southern breeds. High genetic admixing denotes different maternal origins and in contrast to evidence from goats from Levant and Central Asia, where goats were originally domesticated.

Origin of ring defects in high In content green InGaN/GaN MQW: An Ultrasonic Force Microscopy Study

Observation of GaN-based islands surrounded by V-defects in the barrier layer of green LED is reported for InGaN MQWs deposited under no hydrogen or at growth temperatures of less than 800°C. Nanoscale mechanical properties of the areas enclosed and outside of the ring defects does not show any appreciable variation as measured by UFM. Chemical etching of the MQW structure in addition to cross-sectional TEM analysis ruled out the possibility of growth of inversion domains of N-polar GaN in a Ga-polar GaN matrix.

Within-Person Variation of Plasma Homocysteine and Effects of Posture and Tourniquet Application

Background: Frequently, the result of only a single determination of total homocysteine in plasma (P-Hcy) is used to distinguish between the probability of the presence or absence of risk for vascular disease. A prerequisite for the interpretation of a single P-Hcy test is knowledge of the magnitude of within-person variation and the possible effects of preanalytical variables. However, data on within-person variation are still sparse and inconsistent, and data for the effect on P-Hcy of posture and tourniquet application during venipuncture are not available. Methods: The within-person variation of P-Hcy and the effects of posture and tourniquet application during venipuncture were studied in 24 healthy subjects. The analytical imprecision of our stable-isotope dilution assay was 3.1%. Results: The within-person variation (CV) was 8.1%. Daily supplementation with 0.4 mg of folic acid for 2 weeks produced a small but significant decrease in P-Hcy, but there were no significant changes in within-person variation before and after supplementation. After 30 min in the horizontal posture, P-Hcy declined by 6.3%. A 3-min tourniquet application caused a 2.8% increase of P-Hcy. Conclusions: Our value for within-person variation is consistent with results from studies reported recently in the literature. A 3-min tourniquet application does not add appreciable variation to the measurement of P-Hcy, but the posture of the subject during venipuncture contributes considerably to the within-person variation. We recommend that blood collection when the patient is in a supine position be avoided.