Creep strength behavior of boron added P91 steel and its weld in the temperature range of 600–650 degree C

One of the promising ways for mitigation of Type IV cracking – a failure by cracking at the intercritical /fine grained heat affected zone, a life limiting problem in advanced 9–12 Cr ferritic steel weld like that of P91 is through modification of alloy composition by addition of boron. Addition of boron was observed to improve the microstructure at the weld zone and hence the creep strength. In the present work, boron (100 ppm with controlled nitrogen) added P91 steel after normalizing at 1050C and 1150C and tempered at 760C were studied for the creep behavior in the base metal and welded condition in the temperature range of 600–650C. Creep strength was characterized in terms of stress and temperature dependence of creep rate and rupture time. Weld creep life was reduced compared to the base metal with rupture occurring at the ICHAZ (Type IV crack). However at longer time (at lower stress levels) exposure creep crack moves from weld metal to HAZ (Type II crack). Rupture life was found to superior for the base and weld in the boron containing steel when higher normalizing temperature is used. Estimation of 10 5 h was attempted based on short term rupture data available and weld strength factors were calculated. Observed values are better for P91BH condition than the values for P91BL condition as well as those available for P91 in open literatur

Harvesting of Nannochloropsis oculata by chemical flocculation

Microalgae culture forms an inevitable component in aquaculture and mass culture on a commercial scale is essential to satisfy requirement in the hatchery for use as functional foods and nutraceuticals. However, the current microalgal production technologies are not costeffective and face several bottlenecks, among which is the harvesting of microalgal biomass. Typical strategies currently applied for harvesting microalgae include centrifugation, filtration, various forms of flocculation (e.g., chemical inorganic and organic agents, alkaline flocculation, bio-flocculation using microorganisms, and electro-coagulation), sedimentation, and flotation. Among these harvesting methods, flocculation combined with sedimentation of microalgal flocs is considered best with reported cell recovery of > 90% and with low cost. However, the biomass thus recovered with chemical flocculant may cause harm to the final product but it is still regarded as a promising technique. In the present study, the flocculation efficiency of ZnCl2 and ZnSO4 were tested as chemical flocculants for the harvest of Nannochloropsis oculata

Towards messages that matter: Understanding and addressing HIV and SRH risks among married young people in India

Although there is increasing interest in young people\u27s sexual and reproductive health (SRH) situations and needs in India, married young people have received little attention as a vulnerable group with distinct needs because marriage is assumed to be safe and because married youth are assumed to face none of the stigma that their unmarried counterparts experience in accessing SRH services. However, emerging evidence shows that within this subpopulation, married young women and men constitute groups with distinct risks of HIV and other poor SRH outcomes. There remains a need to better understand their unique vulnerabilities and to design programs that take into account their special circumstances. The Population Council and the Family Planning Association of India undertook a research project intended to better understand the situation and vulnerabilities faced by married young women and men, and to develop communication materials for married young women and men and training materials for providers to address HIV and other SRH risks experienced by these subpopulations. The study was conducted in rural settings in Guntur district of Andhra Pradesh, and in Dhar and Guna districts of Madhya Pradesh

Lipid metabolic perturbation is an early-onset phenotype in adult spinster mutants: a Drosophila model for lysosomal storage disorders

Intracellular accumulation of lipids and swollen dysfunctional lysosomes are linked to several neurodegenerative diseases, including lysosomal storage disorders (LSD). Detailed characterization of lipid metabolic changes in relation to the onset and progression of neurodegeneration is currently missing. We systematically analyzed lipid perturbations in spinster (spin) mutants, a Drosophila model of LSD-like neurodegeneration. Our results highlight an imbalance in brain ceramide and sphingosine in the early stages of neurodegeneration, preceding the accumulation of endomembranous structures, manifestation of altered behavior, and buildup of lipofuscin. Manipulating levels of ceramidase and altering these lipids in spin mutants allowed us to conclude that ceramide homeostasis is the driving force in disease progression and is integral to spin function in the adult nervous system. We identified 29 novel physical interaction partners of Spin and focused on the lipid carrier protein, Lipophorin (Lpp). A subset of Lpp and Spin colocalize in the brain and within organs specialized for lipid metabolism (fat bodies and oenocytes). Reduced Lpp protein was observed in spin mutant tissues. Finally, increased levels of lipid metabolites produced by oenocytes in spin mutants allude to a functional interaction between Spin and Lpp, underscoring the systemic nature of lipid perturbation in LSD

Machine Learning Applications in Head and Neck Radiation Oncology: Lessons From Open-Source Radiomics Challenges

Radiomics leverages existing image datasets to provide non-visible data extraction via image post-processing, with the aim of identifying prognostic, and predictive imaging features at a sub-region of interest level. However, the application of radiomics is hampered by several challenges such as lack of image acquisition/analysis method standardization, impeding generalizability. As of yet, radiomics remains intriguing, but not clinically validated. We aimed to test the feasibility of a non-custom-constructed platform for disseminating existing large, standardized databases across institutions for promoting radiomics studies. Hence, University of Texas MD Anderson Cancer Center organized two public radiomics challenges in head and neck radiation oncology domain. This was done in conjunction with MICCAI 2016 satellite symposium using Kaggle-in-Class, a machine-learning and predictive analytics platform. We drew on clinical data matched to radiomics data derived from diagnostic contrast-enhanced computed tomography (CECT) images in a dataset of 315 patients with oropharyngeal cancer. Contestants were tasked to develop models for (i) classifying patients according to their human papillomavirus status, or (ii) predicting local tumor recurrence, following radiotherapy. Data were split into training, and test sets. Seventeen teams from various professional domains participated in one or both of the challenges. This review paper was based on the contestants' feedback; provided by 8 contestants only (47%). Six contestants (75%) incorporated extracted radiomics features into their predictive model building, either alone (n = 5; 62.5%), as was the case with the winner of the “HPV” challenge, or in conjunction with matched clinical attributes (n = 2; 25%). Only 23% of contestants, notably, including the winner of the “local recurrence” challenge, built their model relying solely on clinical data. In addition to the value of the integration of machine learning into clinical decision-making, our experience sheds light on challenges in sharing and directing existing datasets toward clinical applications of radiomics, including hyper-dimensionality of the clinical/imaging data attributes. Our experience may help guide researchers to create a framework for sharing and reuse of already published data that we believe will ultimately accelerate the pace of clinical applications of radiomics; both in challenge or clinical settings

Molecular Recognition Patterns between Vitamin B12 and Proteins Explored through STD-NMR and In Silico Studies

Ligand–receptor molecular recognition is the basis of biological processes. The Saturation Transfer Difference–NMR (STD–NMR) technique has been recently used to gain qualitative and quantitative information about physiological interactions at an atomic resolution. The molecular recognition patterns between the cyanocobalamin (CNBL)/aqua cobalamin (OHBL) and different plant and animal proteins were investigated via STD–NMR supplemented by molecular docking. This study demonstrates that myoglobin has the highest binding affinity and that gluten has the lowest affinity. Casein also shows a higher binding affinity for cyanocobalamin when compared with that of plant-based proteins. STD–NMR results showed the moderate binding capability of casein with both CNBL and OHBL. Computer simulation confirmed the recognition mode in theory and was compared with the experiments. This work is beneficial for understanding the binding affinity and biological action of cyanocobalamin and will attract researchers to use NMR technology to link the chemical and physiological properties of nutrients

Creep Behaviour of 9CrMoNbV (P91) Steel having a Small Amount of Boron

Boron is a added to creep resistant 9CrMo Ferritic steel to overcome the problem of type IV cracking encountered in the critical heat affected zones of welded super-heater tubes. Considerable amount of creep data are available on P91 steel. However similar data on boron containing P91 steel are not readily available in open literature. The paper presents creep and stress rupture data on this steel at several stresses in the temperature range of 600-650oC. Comparison revealed that its creep resistance mar-ginally higher than that of P91 grade steel reported in NIMS creep database. The initial creep rates in all cases were found to be very high. This trend is similar to that in steel without boron. The microstructure of crept spec-imen revealed reduction in dislocation density, coarsening of sub-grains as well as precipitates as result of creep exposure. It is concluded that creep rate decreases initially with decreasing dislocation density until it reaches a minimum and thereafter it increases as a result of coarsening of sub-grains and precipitates

Creep behavior of P91B steel in the presence of a weld joint

The paper presents creep test data on standard P91B steel specimens made from two distinct regions of a welded plate over a range of stresses (50–190 MPa) and temperatures (600–650 1C). The analysis of test data revealed that the samples having a weld zone within the gage length (cross-weld samples) have lower long term rupture strength than the samples made of the base metal. Estimated weld strength factors (WSF) of this steel were found to be higher than those reported for P91 steel. The study also showed that the effect of welding on loss of rupture ductility is much more prominent than its effect on the reduction in rupture strength. In presence of welded zone the extent of local deformation in ruptured samples was not as prominent as in the samples without weld. Creep damage tolerance factors (λ) were estimated from the creep strain versus time plots. This also showed that the magnitude of λ is significantly reduced in the presence of welding. Examination of microstructure and measurement of density revealed that this difference is primarily due to the formation of cavities in the heat affected zones of welded specimens. In the lower stress regime a few test specimens without any welded region did not fail even after very long creep exposure. Diameters of these specimens were found to have increased in spite of measureable increase in length due to creep. This unusual effect has been attributed to oxide scale growth. It shows up when the increase in diameter due to the growth of oxide scale becomes greater than the decrease in diameter due to the accumulation of creep strain

Molecular iodine mediated preparation of isothiocyanates from dithiocarbamic acid salts

We have developed a general economical and environmentally benign method for the preparation of isothiocyanates from the corresponding dithiocarbamic acid salts by using cheap and readily available reagent molecular iodine. This is perhaps the most efficient method reported so far for the synthesis of isothiocyanates. The reagent is easily available and nontoxic, and the precipitated sulfur can be removed easily; hence, this method is most suitable for large‐scale synthesis

Desulfurization mediated by hypervalent iodine(III): A novel strategy for the construction of heterocycles

The desulfurization ability of diacetoxyiodobenzene (DIB) has been explored in the preparation of isothiocyanates from the corresponding dithiocarbamate salts. The in situ generated isothiocyanates reacted with o‐phenylenediamine and o‐aminophenol to form monothioureas, which, on treatment with a further equivalent of DIB in one pot, gave benzimidazoles and aminobenzoxazoles, respectively. Aliphatic 1,2‐diamines on reaction with 2 equiv. of isothiocyanate followed by treatment with DIB gave imidazolidenecarbothioamides, whereas the treatment of aromatic 1,2‐diaminebis(thioureas) yielded benzimidazoles with the concurrent formation of isothiocyanate. The driving force for the formation of the latter is the aromatization of the product. The use of DIB makes these methods simpler and more efficient, giving high yields of the desired products in one pot