Development of 0.2C-CrMnMoV Ultra High Strength Steel

A study was carried out to develop a low alloy ultra high strength steel by induction melting and thermomechanical treatment (TMT) containing alloying elements like carbon, manganese, molybdenum, chromium and vanadium. A base alloy was prepared with 0.24%C, 1.16% Mn, 0.23% Si, 5.61% Cr, 0.42%V, 1.01% Mo, 0.026%S and 0.032%P. It showed tensile strength of 1467 MPa, yield strength of about 1180 MPa, impact strength of 6.3J and elongation of 5.9% in as-tempered condition. Other alloy was prepared by addition of 0.054% titanium with the base composition. It displayed tensile strength, yield strength, impact toughness and % elongation of 1615 MPa, 1240 MPa, 8.2J and 6.15%, respectively. The optical, SEM and TEM microstructures confirmed that the base alloy and the titanium alloy consisted with tempered lath martensites. The remaining part of the ingot was further processed by the thermomechanical treatment. The ingots were rolled in two passes, initially at 950 C and subsequently at 850 C followed by immediate cooling in oil. The TMT plates of the base alloy confirmed the tensile strength of 1755 MPa, yield strength in excess of 1460 MPa and impact strength of 9.1J. The titanium added TMT plate displayed tensile strength of 1860 MPa, yield strength of 1580 MPa and impact strength of 10.1J. Microstructures of titanium added alloy consisted finer lath martensite and precipitates of titanium carbides/carbonitrides. It was observed that the addition of titanium significantly improved the mechanical properties of 0.2C-Cr Mn Mo V alloys and the mechanical properties were also improved significantly by thermomechanical treatment

Impact of biotic and abiotic factors on lac production and peoples’ livelihood improvement in India-An overview

In India, Madhya Pradesh is the third largest lac producing state after Chhattisgarh and Jharkhand, as they contribute 12, 16 and 60%, respectively in total country’s lac production. Lac is produced in ten out of eleven agro-climatic zones of Madhya Pradesh. In total lac production of the state, Baisakhi (Butea monosperma, inoculated in October-November) crop contributes 76% followed by 19% by Katki (Butea monosperma, inoculated in June-July), 3% by Aghani (Schleichera oleosa, inoculated in June-July) and 2% by Jethwi (Schleichera oleosa, inoculated in January-February). Ranchi was leading lac producing district followed by Simdega, Gumla, Khunti of Jharkhand and Seoni district of Madhya Pradesh. Increasing summer temperature up to 45 ?C, the country’s lac production was declined from 20,050 tons in 2003-04 to 16978 tons in 2014-15. In case of biotic factors, Tachardiaephagus tachardiae and Tetrastichus purpureus are the most abundant lac associated parasites and Eublemma amabilis and Pseudohypatopa pulverea are the most destructive key predators of lac insects. By combating these hindrances, lac cultivation generated an employment for 16-160 man days. Lac cultivation produces maximum gross return (Rs. 9,77,600) from 100 Kusum host plants, and the highest Benefit-Cost (6.80) ratio was recorded for Ber-kusumi (Ziziphus mauritiana- Schleichera oleosa) crop in Ranchi, Jharkhand. In this context, the study finds out obstacles in lac production of India and suggests some control measures to improve lac producing peoples’ livelihood. &nbsp

Measuring consumer grade face masks degradation upon sterilization using bright field microscopy

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Remaking Africa's informal economies: youth, entrepreneurship and the promise of inclusion at the bottom of the pyramid

In recent years, the quest for 'inclusive markets' that incorporate Africa's youth has become a key focus of national and international development efforts, with so-called bottom of the pyramid (BoP) initiatives increasingly seen as a way to draw the continent's poor into new networks of global capitalism. SSA has become a fertile frontier for such systems, as capital sets its sights on the continents vast 'under-served' informal economies, harnessing the entrepreneurial mettle of youth to create new markets for a range of products, from solar lanterns and shampoo to cook stoves and sanitary pads. Drawing on ethnographic research with youth entrepreneurs, we trace the prcesses of individual and collective 'transformation' that the mission of (self-) empowerment through entrepreneurship seeks to bring about. We argue that, while such systems are meant to bring those below the poverty line above it, the 'line' is reified and reinforced through a range of discursive and strategic practices that actively construct and embed distinctions between the past and the future, valuable and valueless, and the idle and productive in Africa's informal economies

Unveiling the electronic structure of pseudo-tetragonal WO3_3 thin films

WO$_3$ is a binary 5d compound which has attracted remarkable attention due to the vast array of structural transitions that it undergoes in its bulk form. In the bulk, a wide range of electronic properties has been demonstrated, including metal-insulator transitions and superconductivity upon doping. In this context, the synthesis of WO$_3$ thin films holds considerable promise for stabilizing targeted electronic phase diagrams and embedding them in technological applications. However, to date, the electronic structure of WO$_3$ thin films is experimentally unexplored, and only characterized by numerical calculations. Underpinning such properties experimentally would be important to understand not only the collective behavior of electrons in this transition metal oxide, but also to explain and engineer both the observed optical responses to carriers' concentration and its prized catalytic activity. Here, by means of tensile strain, we stabilize WO$_3$ thin films into a stable phase, which we call pseudo-tetragonal, and we unveil its electronic structure by combining photoelectron spectroscopy and density functional theory calculations. This study constitutes the experimental demonstration of the electronic structure of WO$_3$ thin-films and allows us to pin down the first experimental benchmarks of the fermiology of this system

Morphometric evaluation of seminiferous tubule and proportionate numerical analysis of Sertoli and spermatogenic cells indicate differences between crossbred and purebred bulls

Aim: The present study compared the testicular cytology and histology between crossbred (Holstein–Friesian [HF] × Tharparkar) and purebred (HF and Tharparkar) bulls to find out differences if any. Materials and Methods: Four peripubertal bulls from each breed were utilized for the study. Through percutaneous needle aspiration biopsy, Sertoli and spermatogenic cells were extracted, and morphometry was studied. For histological studies, testicular tissues obtained through unilateral castration were utilized. Sertoli cells specific GATA4 antibody was used to study the population of Sertoli cells in the seminiferous tubule through immunofluorescence. Results: The testicular weight, volume, and scrotal circumference differed significantly among the breeds. The diameter and area of the seminiferous tubule was high in HF, followed by Karan Fries (KF), and Tharparkar bulls. However, the degree of compactness, based on qualitative evaluation, was high in Tharparkar followed by KF and HF bulls. The intensity of Leydig cells was higher in Tharparkar bulls followed by KF and HF. The proportion of Sertoli cells was higher (p<0.05) in HF and Tharparkar bulls compared to KF bulls. Conclusion: It may be concluded that variations exist in testicular components of the breeds studied and the proportion of Sertoli cells in relation to spermatogenic cells was significantly lower in crossbred bulls compared to purebred bulls

Superconductivity in single crystals of a quasi-one dimensional infinite chain cuprate Srx_xCa1−x_{1-x}CuO2_2 at 90 K

Although there is no complete theory of high temperature superconductivity, the importance of CuO$_2$ planes in cuprate superconductors is confirmed from both theory and experiments. Strong Coulomb repulsion between electrons on the CuO$_2$ plane makes the resultant electron system highly correlated and a difficult problem to solve since exact solutions of many-body Hamiltonian in two dimensions do not exist. If however, superconductivity can arise in structures having chains rather than planes and having a high critical temperature, then the high temperature superconductivity problem could become more tractable since exact solutions in one dimension do exist. In this paper, we report the observation of bulk superconductivity in single crystals of a cuprate Sr$_x$Ca$_{1-x}$CuO$_2$ at very high critical temperature, T$_c$, of $\sim$ 90 K whose structure reveals the presence of infinite double chains of Cu-O-Cu-O instead of CuO$_2$ planes, thus, ensuring quasi-one dimensional superconductivity. Bulk superconducting behaviour was observed in \textit{dc} magnetisation, \textit{ac} susceptibility as well as resistance measurements. The observation of bulk superconductivity in Sr$_x$Ca$_{1-x}$CuO$_2$ having chains of Cu-O-Cu-O rather than planes of CuO$_2$ at a high T$_c$ of 90 K is expected to profoundly impact our understanding of high temperature superconductivity.Comment: 15 pages, 4 figure

Podoconiosis, trachomatous trichiasis and cataract in northern Ethiopia: a comparative cross-sectional study

Background: Rural populations in low-income countries commonly suffer from the co-morbidity of neglected tropical diseases (NTDs). Podoconiosis, trachomatous trichiasis (both NTDs) and cataract are common causes of morbidity among subsistence farmers in the highlands of northern Ethiopia. We explored whether podoconiosis was associated with cataract or trachomatous trichiasis (TT) among this population. Methods: A comparative cross-sectional study was conducted in East Gojam region, Amhara, Ethiopia in May 2016 . Data were collected from patients previously identified as having podoconiosis and from matched healthy neighbourhood controls. Information on socio- demographic factors, clinical factors and past medical history were collected by an interview-administered questionnaire. Clinical examination involved grading of podoconiosis by examination of both legs, measurement of visual acuity, direct ophthalmoscopy of dilated pupils to grade cataract, and eyelid and corneal examination to grade trachoma. Multiple logistic regression was conducted to estimate independent association and correlates of podoconiosis, TT and cataract. Findings: A total of 700 participants were included in this study; 350 podoconiosis patients and 350 healthy neighbourhood controls. The prevalence of TT was higher among podoconiosis patients than controls (65 (18.6%) vs 43 (12.3%)) with an adjusted odds ratio (OR) 1.55 (95% Confidence Interval (CI) 1.12 - 2.11), p=0.05. There was no significant difference in 3 prevalence of cataract between the two populations with an adjusted OR 0.83 (95% CI 0.55-1.38), p=0.37. Mean best visual acuity was 0.59 (SD +/- 0.06) in podoconiosis cases compared to 0.44 (SD +/- 0.04) in controls, p=< 0.001. The proportion of patients classified as blind was higher in podoconiosis cases compared with healthy controls; 5.6% vs 2.0%; adjusted OR 2.63 (1.08-6.39), P = 0.03. Conclusions Individuals with podoconiosis have a higher burden of TT and worse visual acuity than their matched healthy neighbourhood controls. Further research into the environmental and biological reasons for this co-morbidity is required. A shared approach to managing these two NTDs within the same population could be beneficial