COMPUTATIONAL FLUID DYNAMICS (CFD) MODELING AND VALIDATION OF DUST CAPTURE BY A NOVEL FLOODED BED DUST SCRUBBER INCORPORATED INTO A LONGWALL SHEARER OPERATING IN A US COAL SEAM

Dust is a detrimental, but unavoidable, consequence of any mining process. It is particularly problematic in underground coal mining, where respirable coal dust poses the potential health risk of coal workers’ pneumoconiosis (CWP). Float dust, if not adequately diluted with rock dust, also creates the potential for a dust explosion initiated by a methane ignition. Furthermore, recently promulgated dust regulations for lowering a miner’s exposure to respirable coal dust will soon call for dramatic improvements in dust suppression and capture. Computational fluid dynamics (CFD) results are presented for a research project with the primary goal of applying a flooded-bed dust scrubber, with high capture and cleaning efficiencies, to a Joy 7LS longwall shearer operating in a 7-ft (2.1 m) coal seam. CFD software, Cradle is used to analyze and evaluate airflow patterns and dust concentrations, under various arrangements and conditions, around the active mining zone of the shearer for maximizing the capture efficiency of the scrubber

Disorder-induced critical exponents near a ferromagnetic quantum critical point in Mn1−xCrxSi

We report the observation of critical behavior in Mn1−xCrxSi (0≤x≤1) close to a T = 0 K quantum critical point, consistent with the Belitz-Kirkpatrick-Vojta (BKV) theory of disordered metallic ferromagnets. The critical exponents are in good agreement with the theoretical predictions of the BKV theory in the preasymptotic limit. A non-Fermi liquid-like behavior is seen down to 200 mK in the transport and thermodynamic properties around the critical concentration xC = 0.2. Quantum criticality and self-consistency of the exponents is further confirmed using a scaling analysis of the magnetization and heat capacity data. A recovery to Fermi liquid-like behavior is displayed on moving away from the critical composition, as well as with the application of a magnetic field

Temperature dependence of 1/f noise in Gallium Nitride epitaxial layer

1/f noise investigation was performed on n-GaN epitaxial layer grown on sapphire. The variation of spectral power density of voltage fluctuations density was observed as a function of frequency (100-50 Hz) and it showed the 1/f spectra. This type of behavior was attributed to the presence of traps. The variation in spectral power density of voltage fluctuations with temperature was also observed with in the temperature range 80 K and 300 K and it was found to be slightly increasing with temperature. It was attributed to the trapping-detrapping process of charge carriers by the defects. Four probe configuration was used for noise measurement and contacts were made with indium. To check the stability and ohmic behavior of contacts, I-V measurements were performed with in the temperature range 80-325 K. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2201

Investigation of current-voltage characteristics of Ni/GaN Schottky barrier diodes for potential hemt applications

In the present work, the I-V characteristics of Ni/GaN Schottky diodes have been studied. The Schottky diodes, having different sizes using Ni/Au and ohmic contacts using Ti/Al/Ni/Au were made on n-GaN. The GaN was epitaxially grown on c-plane sapphire by metal organic chemical vapor deposition (MOCVD) technique and had a thickness of about 3.7 μm. The calculated ideality factor and barrier height from current-voltage (I-V) characteristics (at 300 K) for two GaN Schottky diodes were close to ~1.3 and ~ 0.8 eV respectively. A high reverse leakage current in the order of 10 – 4A/cm2 (at – 1 V) was observed in both diodes. A careful analysis of forward bias I-V characteristics showed very high series resistance and calculation for ideality factor indicated presence of other current transport mechanism apart from thermionic model at room temperature. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2202

IterMiUnet: A lightweight architecture for automatic blood vessel segmentation

The automatic segmentation of blood vessels in fundus images can help analyze the condition of retinal vasculature, which is crucial for identifying various systemic diseases like hypertension, diabetes, etc. Despite the success of Deep Learning-based models in this segmentation task, most of them are heavily parametrized and thus have limited use in practical applications. This paper proposes IterMiUnet, a new lightweight convolution-based segmentation model that requires significantly fewer parameters and yet delivers performance similar to existing models. The model makes use of the excellent segmentation capabilities of Iternet architecture but overcomes its heavily parametrized nature by incorporating the encoder-decoder structure of MiUnet model within it. Thus, the new model reduces parameters without any compromise with the network's depth, which is necessary to learn abstract hierarchical concepts in deep models. This lightweight segmentation model speeds up training and inference time and is potentially helpful in the medical domain where data is scarce and, therefore, heavily parametrized models tend to overfit. The proposed model was evaluated on three publicly available datasets: DRIVE, STARE, and CHASE-DB1. Further cross-training and inter-rater variability evaluations have also been performed. The proposed model has a lot of potential to be utilized as a tool for the early diagnosis of many diseases

Role of high resolution sonography and color Doppler flow imaging in the evaluation of scrotal pathology

Background: Scrotal swelling and pain are frequently encountered in clinical practice. Although to reach a diagnosis in some patients, history and physical examination are adequate, yet in a large percentage of patients, some additional studies are essential for complete evaluation of their symptoms. The clinical examination is often misleading or non-specific. The study shows the application of Gray-scale sonography, Color Doppler flow imaging (CDFI) and Power Doppler (PD) in the diagnosis of swelling, malposition, torsion, trauma, varicocele, hydrocele, cyst, mass, and atrophy.Methods: A total of 93 patients from all age groups with symptoms related to scrotal disease have been included in this study. Gray-scale sonography, CDFI and PD sonography of scrotal lesions were carried out.Results: A good correlation was seen in the comparison of scrotal lesions between sonography (gray scale, CDFI, and PD) and histopathology/ treatment response.Conclusions: High-resolution sonography, along with color Doppler flow imaging and power Doppler should be used as the first-line investigation in the evaluation of scrotal pathologies. Color Doppler flow Imaging and power Doppler add useful information and complement gray-scale sonography in reaching a correct diagnosis

Coupled Evolutionary Behavioral and Disease Dynamics under Reinfection Risk

We study the interplay between epidemic dynamics and human decision making for epidemics that involve reinfection risk; in particular, the susceptible-infected-susceptible (SIS) and the susceptible-infected-recovered-infected (SIRI) epidemic models. In the proposed game-theoretic setting, individuals choose whether to adopt protection or not based on the trade-off between the cost of adopting protection and the risk of infection; the latter depends on the current prevalence of the epidemic and the fraction of individuals who adopt protection in the entire population. We define the coupled epidemic-behavioral dynamics by modeling the evolution of individual protection adoption behavior according to the replicator dynamics. For the SIS epidemic, we fully characterize the equilibria and their stability properties. We further analyze the coupled dynamics under timescale separation when individual behavior evolves faster than the epidemic, and characterize the equilibria of the resulting discontinuous hybrid dynamical system for both SIS and SIRI models. Numerical results illustrate how the coupled dynamics exhibits oscillatory behavior and convergence to sliding mode solutions under suitable parameter regimes.Comment: arXiv admin note: text overlap with arXiv:2203.1027

Research Journal of Pharmaceutical, Biological and Chemical Sciences Nanomagnetites Green Synthesis Assisted by Sunflower Oil

ABSTRACT Nanomagnetites were used as a most efficient agent for removal of heavy metals such as As and Cr for cleaning polluted water as heavy-metal contamination in groundwater is one of the severe global problems. In India, arsenic poisoning is very common but the major hurdle in synthesizing nanomagnetite in the lab is, high cost by decomposition method using FeOOH and oleic acid in 1-ODE. Here we are trying to synthesize cost effective nanomagnetites by using common materials present in our daily life such as sunflower oil, common vinegar and drain opener, which are freely available in the market. By this cost effective greener method, It is possible to synthesize high-quality nanocrystals. Our research confirms that by using this greener synthetic route we can reduce the cost of starting materials

Use of autogenous internal iliac artery for bridging the external iliac artery after excision of Aspergillus mycotic aneurysm in renal transplant recipients

Repair of vascular defects in the presence of infection remains a challenging task in immunocompromised patients. We report two patients with postrenal transplant Aspergillus mycotic aneurysms of the allograft renal artery involving the external iliac artery which were excised along with the allograft. The defect in the external iliac artery was repaired successfully with interposition of autogenous internal iliac artery graft. Use of an internal iliac artery graft in such settings has been rarely reported in English literature. Autogenous internal iliac artery grafts provide a useful method to bridge the vascular defects created by radical debridement in the presence of fungal infections