A Mechanism Based Investigation Of The Dynamic Behavior Of Pure Magnesium

The global emphasis on improving energy efficiency in recent years has propelled the development of new engineering solutions to meet the high efficiency standards. The push from the transportation industry to achieve weight reduction of automobiles/components (in order to meet the higher standards for fuel efficiency) has renewed interest in lightweight materials such as magnesium (Mg). Mg alloys have low density and high specific strengths which makes them attractive in applications where their increased use can lead to significant energy savings. In order to successfully use these materials in applications in which they will be subjected to dynamic loading such as automotive, aerospace and defense applications, we need to assess and understand their behavior under such conditions. The deformation behavior of this HCP material is complicated by the richness of the slip and twinning modes and their interactions and dynamic loading may introduce additional complexities. High strain rate (Kolsky bar) and normal plate impact experiments were performed on pure extruded magnesium to analyze the mechanical behavior. Microstructural analysis of the pre and post deformation samples was performed in order to understand the dominant deformation mechanisms and their evolution. Optical microscopy and electron back scattered diffraction (EBSD) was performed to analyze deformation twinning and transmission electron microscopy (TEM) was performed to analyze the dislocation structures. It was observed that under uniaxial stress compression at high strain rates (10^3 /s) in the ED (induced by Kolsky bars), extension twinning, slip and slip are necessary to accommodate plastic strains. The microstructural observations show that extension twinning reorients the material by 86^0 to a harder orientation and causes a significant change in the texture. The insights gained from the analysis of the evolution of the dominant deformation mechanisms are used to develop a simple mechanism based constitutive model which captures the behavior of single and polycrystalline Mg. The normal plate impact experiments conducted (on both single crystal and polycrystalline Mg) at 60-70 m/s impose a uniaxial strain loading for very short durations (~2 μs). Elastic-plastic plate impact simulations performed in Abaqus/Explicit show that the stress, strain and strain rate in the specimen thickness are inhomogeneous in these experiments. Deformation twinning is observed under this loading of very short duration although the characteristics of the twins formed under this loading are different than those induced by the Kolsky bar loading (~200 μs). The twins induced by the plate impact loading are thinner and occupy smaller volume fraction as compared to the ones induced by the Kolsky bar loading. The observations from both the experiments indicate that the differences in the deformation twinning characteristics arise from the differences in the stress states, strain rates and the loading durations in the two cases. These observations help us further our understanding of the mechanisms controlling the dynamic behavior of pure magnesium

Biodegradation of textile dye effluent through Indigenous bacteria

The textile industry is considered as one of the major generators of toxic chemical wastewater in India. Dyes released by the textile industries pose a threat to environmental safety. Dye decolorization through biological means has gained momentum as these are cheap and can be applied to a wide range of dyes. The present study concentrates in the isolation, identification of indigenous bacteria namely D1, D2, D3 and D4 from textile dye effluent collected from the local textile dyeing shop located at Gurahakuan, Banda district, Uttar Pradesh, India, and evaluation of their ability to decolorize dyes sample. The isolated bacteria were identified through morphological and biochemical characteristics. Scanning electron microscope (SEM) analysis of isolated bacteria showed that all the bacteria appeared rod-shaped with size ranging from 1.33 to 2.84 µm. The physico-chemical analysis of dye effluent indicated the bluish-black color of the effluent having pH of about 8. The Biological Oxygen Demand (BOD) and Chemical Oxygen Demand (COD) value of the raw sample was estimated to be 470 mg/l and 800 mg/l, respectively, for dye effluent sample. The value of Total Dissolved Solids (TDS) and Total Suspended Solids (TSS) was estimated to be 1760 mg/l and 560 mg/l, respectively, in our dye effluent sample. The study aims to isolate and optimize four bacterial isolates having the ability to degrade and decolorize azo dyes produced in the final dying effluent. The optimization results revealed that all the bacteria showed maximum growth at pH 8, temperature 35°C and declines further. All the isolated bacterial species showed significant potential for dye decolorization and degradation at varying wavelengths such as 420, 480, 506, 520, 620 and 668 nm but maximum removal of color (about 88%) was obtained at 668 nm after 48h by bacterial isolate D3. Thus, these selected native bacteria can be employed as a vital biological tool for developing decentralized wastewater treatment systems for decolorization of dye effluents through biosorption or biodegradation which is a cost-effective process

Kinetics of twinning in magnesium under dynamic loading

Twinning is an important mode of deformation in many HCP materials including magnesium (Mg) and its alloys. Twinning in this material leads to important effects such as mechanical anisotropy, texture evolution, tension–compression asymmetry, and sometimes non-Schmid effects. Dynamic loading can introduce further complexity in the deformation behavior. The growth of twins takes place by the motion of the twin boundary (TB). Tension twins in Mg can accommodate considerable amounts of plastic deformation as they grow, and this affects the overall rate of plastic deformation. Detailed understanding of the kinetics of TB motion will enable us to work towards achieving the overarching goal of microstructural design of materials for performance. We undertake an experimental approach to gain insight into the kinetics of TB migration under dynamic loading. To achieve this goal we performed normal plate impact recovery experiments with microsecond pulse durations on pure polycrystalline Mg specimens. Estimates of average TB velocity under the known impact stress are obtained by characterization of twin sizes and aspect ratios developed within the target during the loading pulse. The measured average TB velocities in our experiments are of the order of several meter per second. These velocities are several orders of magnitude higher than those measured in Mg under quasi-static loading conditions. Further, twin nucleation and growth processes are investigated by conducting experiments with different durations of the loading pulse. This is achieved by using Mg specimens of different thicknesses. Electron back scattered diffraction is used to characterize the nature of the twins, microstructure, and twin fraction evolution. Detailed crystallographic analysis of the twins enables us to correlate the TB velocities to the twin variants

Hybrid Approach for Heart Disease Detection Using Clustering and ANN

Data mining is a process of extracting data from data set and transforming it into understandable structure for further use. Data mining techniques have been applied magnificently in many fields including business, science and bio informatics, and on different types of data like textual, visual, spatial, and real-time and sensor data. Heart disease prediction is treated as most difficult task in the field of medical sciences. Heart disease detection using data mining can answer complicated queries for diagnosing heart disease and thus assist healthcare practitioners to make intelligent clinical decisions which traditional decision support systems cannot. By providing effective treatments, it also helps to reduce treatment costs. The aim of this study is to develop an artificial neural networks-based diagnostic model for heart disease using a complex of traditional and genetic factors of this disease

Phycoremediation of Dairy Wastewater by Microalgae for elimination of organic pollution load

The present study aims to demonstrate the potential of microalgae Chlorococcum humicola for treatment of dairy industry effluent and reduction of its pollution load with the cultivation of microalgae in the same effluent. Dairy industry wastewater supplies the required nutrients for the growth of C. humicola and its growth was comparatively higher in 50 % dairy industry effluent as compare to Bold basal growth medium. Optimization of growth parameters of algae showed that growth of C. humicola was favoured by alkaline pH and optimum growth was observed at pH 8, whereas acidic pH does not favour the growth of selected algae. The exponential growth phase of C. humicola was achieved between 3-7 days, at 20˚C temperature, a further increase in temperature decreases the algal growth. The results for the effect of different concentration of dairy wastewater (0, 10, 25, 50, 75 and 100 %) on biochemical content (protein, chlorophyll a, carbohydrate) of C. humicola revealed that 50 % wastewater concentration was more efficient for enhancement of biochemical content of microalgae as compare to control. The result further showed considerable reduction in the organic pollution load of dairy wastewater as biological oxygen demand (BOD) and chemical oxygen demand (COD) reduced to 72 and 78 % respectively, after 15 days of treatment with C. humicola. The results also showed a reduction in the nutrient concentration of dairy wastewater such as nitrate, phosphate and sulphate by 92, 43, 62 % respectively, after 10 days of treatment and 96, 67 and 78 % respectively, after 15 days of microalgal treatment as compared to control (without microalgae). These findings suggested that dairy industry wastewater was a good nutrient supplement and can be directly used for mass cultivation of C. humicola without requiring additional nutrient supplements and also the microalgae C. humicola has a great potential for the treatment of dairy industry wastewate

A rare case of primary parasitic leiomyoma mimicking as ovarian mass: a clinical dilemma

Uterine leiomyomas are the most common benign pelvic tumors in women of reproductive age group. Parasitic or wandering leiomyomas are known for their rarity, atypical clinical presentation & unusual location, posing challenge in making radiological and clinical diagnosis. More recently, rise in incidence of secondary parasitic leiomyomas has been reported as a complication of laparoscopic myomectomy and morcellations. We report an interesting case of primary parasitic leiomyoma which initially seemed to be a case of ovarian tumor. A 38 year old woman presented with chief complaints of pain in lower abdomen since 4 months with abdominal swelling since 2 months with CT abdomen suggestive of 8.7x5.2 cm exophytic right ovarian neoplasm with differential diagnosis of broad ligament fibroid in pouch of douglas. She had no previous history of abdominal or laparoscopic myomectomy and no family history of genital tract and breast malignancy. On clinical examination, no mass could be palpated per abdominally but a firm mass of 8 x6 cm size was felt through posterior fornix. Intraoperatively, a solid mass with lobulated surface was noted in pouch of Douglas attached through a thin vascular pedicle to sigmoid colon. Differential diagnosis considering location of tumor and pathological examination included possibility of gastrointestinal stromal tumor or extra-gastrointestinal stromal tumor or wandering leiomyoma. However, on histopathological slide examination (using immunohistochemistry), GIST was ruled out and diagnosis of parasitic fibroid was confirmed. Therefore, while dealing with pelvic tumors with atypical clinical presentation, possibility of these rare tumors have to be kept in mind for appropriate management

Baseline T cell dysfunction by single cell network profiling in metastatic breast cancer patients.

BackgroundWe previously reported the results of a multicentric prospective randomized trial of chemo-refractory metastatic breast cancer patients testing the efficacy of two doses of TGFβ blockade during radiotherapy. Despite a lack of objective responses to the combination, patients who received a higher dose of TGFβ blocking antibody fresolimumab had a better overall survival when compared to those assigned to lower dose (hazard ratio of 2.73, p = 0.039). They also demonstrated an improved peripheral blood mononuclear cell (PBMC) counts and increase in the CD8 central memory pool. We performed additional analysis on residual PBMC using single cell network profiling (SCNP).MethodsThe original trial randomized metastatic breast cancer patients to either 1 or 10 mg/kg of fresolimumab, every 3 weeks for 5 cycles, combined with radiotherapy to a metastatic site at week 1 and 7 (22.5 Gy given in 3 doses of 7.5 Gy). Trial immune monitoring results were previously reported. In 15 patients with available residual blood samples, additional functional studies were performed, and compared with data obtained in parallel from seven healthy female donors (HD): SCNP was applied to analyze T cell receptor (TCR) modulated signaling via CD3 and CD28 crosslinking and measurement of evoked phosphorylation of AKT and ERK in CD4 and CD8 T cell subsets defined by PD-1 expression.ResultsAt baseline, a significantly higher level of expression (p < 0.05) of PD-L1 was identified in patient monocytes compared to HD. TCR modulation revealed dysfunction of circulating T-cells in patient baseline samples as compared to HD, and this was more pronounced in PD-1+ cells. Treatment with radiotherapy and fresolimumab did not resolve this dyfunctional signaling. However, in vitro PD-1 blockade enhanced TCR signaling in patient PD-1+ T cells and not in PD-1- T cells or in PD-1+ T cells from HD.ConclusionsFunctional T cell analysis suggests that baseline T cell functionality is hampered in metastatic breast cancer patients, at least in part mediated by the PD-1 signaling pathway. These preliminary data support the rationale for investigating the possible beneficial effects of adding PD-1 blockade to improve responses to TGFβ blockade and radiotherapy.Trial registrationNCT01401062