The present work aims to study the effect of novel sub-transus heat treatment on the microstructure evolution and hardness of Ti6Al4V alloy fabricated using laser based powder bed fusion. The results ...revealed that the as-built microstructure is α′ martensite which decomposes to α + β during sub-transus heat treatment at 970 °C for different soaking times. The formation of a bi-modal structure with approximately 25% globular primary α and transformed β is observed. The development of globular primary alpha is attributed to thermal grooving and boundary splitting. The resultant coarsening of these α/β grains was associated with a time-temperature combination and orientation relation (OR) to 45° 100. Moreover, precipitation of fine Ti3Al intermetallic (α2) in plate form is observed predominantly inside the primary α grains. Owing to the faster cooling rate post soaking time resulted in Ti3Al precipitates which is the conversion of α to α2 precipitates. The average micro-hardness of the specimen heat-treated for 12 h at 970 °C is found to be 45% higher in comparison to the as-built specimen. Whereas, the micro-hardness differs between the primary α and transformed β region due to the alloy element partitioning effect. The average micro-hardness of 592 HV is observed in primary α grains in the specimen heat-treated for 12 h at 970 °C. The prior results are associated with the formation of intermetallic nano-sized Ti3Al (α2).
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•Microstructure evolution of heat-treated SLM-built Ti6Al4V alloy for different soaking times (1–12 h).•Novel approach for the development of high hardness.•Formation of a bi-modal structure with approximately 25% globular primary α and transformed β.•Hardness increases by 45% (379 HV to 550 HV) in the SLM-built specimens due to the partitioning effect.•Coarsening of β-phase with orientation relative to 45° 100 at α/β phase boundaries for 12 h soaking time.
A 20-year-old male was admitted in the critical care unit with alleged history of blunt trauma to head and neck that was caused by falling heavy object while working at a construction site. 6 ...Although conventional radiography still plays an important role in the initial emergency room setting, for follow-up in the intensive care unit, multidetector computed tomography has established itself as the standard imaging method for the evaluation of chest trauma patients.
Mg3Sb2‑xBi x solid-solutions represent an important class of thermoelectric (TE) materials due to their high efficiency and variable operating temperature range. Of particular significance for ...midtemperature applications is the Mg3Sb1.5Bi0.5 composition whose superior thermoelectric (TE) performance is attributed to the complex conduction band edge in conjunction with alloy dominated phonon scattering. In this work, we show that microstructure also plays a significant role in lowering the lattice thermal conductivity which in turn affects the overall TE performance (change in peak zT values between 1.1 and 1.4 have been observed). Temperature dependent TE properties of Mg3+xSb1.5Bi0.5 compositions with varying nominal Mg content (x = 0.2, 0.3, 0.4) have been studied. A marked reduction of the lattice thermal conductivity (κL) is observed in compositions with low nominal Mg content (x = 0.2), which is due to the presence of lamellar structures within the grains. These lamellar regions are isostructural to the matrix with a low misfit angle and represent compositional fluctuations in the Bi to Sb ratio. Both the size (200 nm-500 nm) and the interfacial strain contribute to the enhanced phonon scattering. A quantitative estimate of κL reduction due to these structures have been carried out using a mean free path (MFP) spectrum analysis which reveal a good match with experiments at room temperature. Further, the electrical properties are not influenced by these lamellar structures as observed from the similar power-factor (S 2σ) and weighted mobilities in all of the compositions. This is due to their similar orientation to the adjacent matrix region. Thus, the zT parameter in the various compositions with similar carrier concentration can be significantly altered (∼25%) by adjusting the nominal Mg content. The results demonstrate that preferential phonon scattering by microstructure modification can be a new route for property improvement in Mg3+x Sb2–y Bi y solid-solutions.
This is a case report of a young adult presenting with hemorrhagic pleural effusion. Chest CT scan showed loculated pleural effusion with pleural nodule. Whole body PET scan showed thickening of ...pleura with multiple enhancing pleural nodules with different metabolic activity. Pleural nodule was biopsied which on histopathology showed pleural synovial sarcoma.
The explosive growth of malware variants poses a major threat to information security. Malware is the one which frequently growing day by day and becomes major threats to the Internet Security. ...According to numerous increasing of worm malware in the networks nowadays, it became a serious danger that threatens our computers. Networks attackers did these attacks by designing the worms. A designed system model is needed to defy these threats, prevent it from multiplying and spreading through the network, and harm our computers. In this paper, we designed a classification on system model for this issue. The designed system detects the worm malware that depends on the information of the dataset that is taken from website, the system will receive the input package and then analyze it, the Naïve Bayesian classification technique will start to work and begin to classify the package, by using the data mining Naïve Bayesian classification technique, the system worked fast and gained great results in detecting the worm. By applying the Naïve Bayesian classification technique using its probability mathematical equations for both threat data and benign data, the technique will detect the malware and classify data whether it was threat or benign.
Tissue engineering has enabled the development of advanced and physiologically relevant models of cardiovascular diseases, with advantages over conventional 2D in vitro assays. We have previously ...demonstrated development of a heart on-a-chip microfluidic model with mature 3D anisotropic tissue formation that incorporates both stem cell-derived cardiomyocytes and cardiac fibroblasts within a collagen-based hydrogel. Using this platform, we herein present a model of myocardial ischemia on-a-chip, that recapitulates ischemic insult through exposure of mature 3D cardiac tissues to hypoxic environments. We report extensive validation and molecular-level analyses of the model in its ability to recapitulate myocardial ischemia in response to hypoxia, demonstrating the 1) induction of tissue fibrosis through upregulation of contractile fibers, 2) dysregulation in tissue contraction through functional assessment, 3) upregulation of hypoxia-response genes and downregulation of contractile-specific genes through targeted qPCR, and 4) transcriptomic pathway regulation of hypoxic tissues. Further, we investigated the complex response of ischemic myocardial tissues to reperfusion, identifying 5) cell toxicity, 6) sustained contractile irregularities, as well as 7) re-establishment of lactate levels and 8) gene expression, in hypoxic tissues in response to ischemia reperfusion injury.
Obesity is a consequence of a complex interplay between the host genome and the prevalent obesogenic factors among the modern communities. The role of gut microbiota in the pathogenesis of the ...disorder was recently discovered; however, 16S-rRNA-based surveys revealed compelling but community-specific data. Considering this, despite unique diets, dietary habits and an uprising trend in obesity, the Indian counterparts are poorly studied. Here, we report a comparative analysis and quantification of dominant gut microbiota of lean, normal, obese and surgically treated obese individuals of Indian origin. Representative gut microbial diversity was assessed by sequencing fecal 16S rRNA libraries for each group (n = 5) with a total of over 3000 sequences. We detected no evident trend in the distribution of the predominant bacterial phyla, Bacteroidetes and Firmicutes. At the genus level, the bacteria of genus Bacteroides were prominent among the obese individuals, which was further confirmed by qPCR (P < 0.05). In addition, a remarkably high archaeal density with elevated fecal SCFA levels was also noted in the obese group. On the contrary, the treated-obese individuals exhibited comparatively reduced Bacteroides and archaeal counts along with reduced fecal SCFAs. In conclusion, the study successfully identified a representative microbial diversity in the Indian subjects and demonstrated the prominence of certain bacterial groups in obese individuals; nevertheless, further studies are essential to understand their role in obesity.
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