Experimental and parametric studies of a louvered fin and flat tube compact heat exchanger using computational fluid dynamics

AbstractThe present study aimed to perform the parametric analysis on thermo-hydraulic performance of a compact heat exchanger using computational fluid dynamics (CFD). The analysis has been carried out at different frontal air velocities by varying the geometrical parameters such as fin pitch, transverse tube pitch, longitudinal tube pitch, louver pitch and louver angle. The air side performance of the heat exchanger has been evaluated by calculating Colburn factor (j) and Fanning friction factor (f). The comparison of CFD results with the experimental data exhibited a good agreement and the influence of various geometrical parameters for the selected range of values on the pressure drop, heat transfer coefficient and goodness factor was analyzed. The results obtained from the analysis will be very useful to optimize the louvered fin and flat tube compact heat exchanger for better thermo-hydraulic performance analysis without the need of time consuming and expensive experimentation

Gynocentrism in Langston Hughes selected poetic works

Gynocentrism exclusive focuses on women both as theory and practice. Anything can be considered gynocentric when it is concerned exclusively with a female point of view. The works of Langston Hughes, which reflect the intersection of races and genders in the lives of blacks, are studied. His contributions take multiple forms including poetry, short stories, dramas and novels which are about black women's love, nature, romantic dilemmas, mother - daughter relationships, friendship, and silences. The authors analyze how gender in a special way colors female identity in Hughes' works. He expresses interdependence of genders and racial identities in his representations of black women and hence can be dubbed as gender racial. His writings are in a gender racial style, highlighting and intertwining gender and racial identities. Hughes' overcomes gender and racial stereotypes with open discussions on contentious themes. It is concluded that Hughes creates an alternative to repressive social realities by combining challenges with sensual visions

Targeting Btk/Etk of prostate cancer cells by a novel dual inhibitor.

Btk and Etk/BMX are Tec-family non-receptor tyrosine kinases. Btk has previously been reported to be expressed primarily in B cells and has an important role in immune responses and B-cell malignancies. Etk has been shown previously to provide a strong survival and metastasis signal in human prostate cancer cells, and to confer androgen independence and drug resistance. While the role of Etk in prostate carcinogenesis is well established, the functions of Btk in prostate cancer have never been investigated, likely due to the perception that Btk is a hematopoietic, but not epithelial, kinase. Herein, we found that Btk is overexpressed in prostate cancer tissues and prostate cancer cells. The level of Btk in prostate cancer tissues correlates with cancer grades. Knockdown of Btk expression selectively inhibits the growth of prostate cancer cells, but not that of the normal prostate epithelial cells, which express very little Btk. Dual inhibition of Btk and Etk has an additive inhibitory effect on prostate cancer cell growth. To explore Btk and Etk as targets for prostate cancer, we developed a small molecule dual inhibitor of Btk and Etk, CTN06. Treatment of PC3 and other prostate cancer cells, but not immortalized prostate epithelial cells with CTN06 resulted in effective cell killing, accompanied by the attenuation of Btk/Etk signals. The killing effect of CTN06 is more potent than that of commonly used inhibitors against Src, Raf/VEGFR and EGFR. CTN06 induces apoptosis as well as autophagy in human prostate cancer cells, and is a chemo-sensitizer for docetaxel (DTX), a standard of care for metastatic prostate cancer patients. CTN06 also impeded the migration of human prostate cancer cells based on a 'wound healing' assay. The anti-cancer effect of CTN06 was further validated in vivo in a PC3 xenograft mouse model

An Investigation on the Morphological and Mineralogical Characteristics of Posidonius Floor Fractured Lunar Impact Crater Using Lunar Remote Sensing Data

Lunar floor‐fractured craters (FFCs) are a distinguished type of crater found on the surface of the Moon with radial, concentric, and/or polygonal fractures. In the present study, we selected the Posidonius FCC to explore the mineralogy, morphology and tectonic characteristics using remote sensing datasets. The Posidonius crater is vested with a wide moat of lava separating the crater rim inner wall terraces from the fractured central floor. Lunar Reconnaissance Orbiter’s (LRO) images and Digital Elevation Model (DEM) data were used to map the tectonics and morphology of the present study. The Moon Mineralogy Mapper (M3) data of Chandrayaan‐1 were used to inves-tigate the mineralogy of the region through specified techniques such as integrated band depth, band composite and spectral characterization. The detailed mineralogical analysis indicates the nor-itic‐rich materials in one massif among four central peak rings and confirm intrusion (mafic pluton). Spectral analysis from the fresh crater of the Posidonius moat mare unit indicates clinopyroxene pigeonite in nature. Integrated studies of the mineralogy, morphology and tectonics revealed that the study region belongs to the Class‐III category of FFCs. The lithospheric loading by adjacent volcanic load (Serenitatis basin) generates a stress state and distribution of the fracture system

Effect of Phosphorus on the leaf yield, nutrient uptake and P-use efficiencies of sun cured chewing tobacco (Nicotiana tobacum) grown in Tamil Nadu

A field experiment was conducted during 2005-2009 to study the effect of various P management practices on the productivity, chewing quality, nutrient uptake, P-use efficiencies on chewing tobacco. There is a dire need to reduce the P requirement for chewing tobacco (Nicotiana tabacum L.), as it is costlier and scarce. First grade leaf yield (FGLY) and total cured leaf yield (TCLY) with 50,75 and 100% recommended P with or without phospho bacteria (PSB) are comparable. The FGLY and TCLY increase varied between 7 to 20 % and 19 to 30 % respectively over no P. Phosphorus application irrespective of the levels improved the chewability (Score >60) over no P. The uptake of NPK and soil available P improved with levels of P with or without PSB over no P. Phosphorus application every year improved the soil available P. The P balance showed loss of P in all the treatments. P-use efficiency (39.5- 42.3 kg/kg), P-uptake efficiency (0.12 - 0.15 kg/kg) , agronomic efficiency (0.12 - 0.15 kg/kg) , recovery efficiency (7.27 7.55%) and partial factor productivity (138 - 148 kg/kg) was higher at 50% P with or without PSB. Physiological efficiency was higher at 100% P +PSB (315 kg/ha) in the first year and 50% P (395.3 kg/ha) in the second year. Net returns and B:C ratio with 100% P was comparable with 75 and 50 % P with or without PSB. It was concluded that 50% recommended P (22 kg P/ha) would be sufficient for higher yield , net returns, better leaf chemistry and P-use efficiency

Delayed Treatment of Diagnosed Pulmonary Tuberculosis in Taiwan

<p>Abstract</p> <p>Background</p> <p>Mycobacterium tuberculosis infection is an ongoing public health problem in Taiwan. The National Tuberculosis Registry Campaign, a case management system, was implemented in 1997. This study examined this monitoring system to identify and characterize delayed treatment of TB patients.</p> <p>Methods</p> <p>Records of all tuberculosis cases treated in Taiwan from 2002 through 2005 were obtained from the National Tuberculosis Registry Campaign. Initiation of treatment more than 7 days after diagnosis was considered a long treatment delay.</p> <p>Results</p> <p>The study included 31,937 patients. The mean day of delayed treatment was 3.6 days. Most patients were treated immediately after diagnosis. The relationship between number of TB patients and days of delayed treatment after diagnosis exhibited a Power-law distribution. The long tail of the power-law distribution indicated that an extreme number occur cannot be neglected. Tuberculosis patients treated after an unusually long delay require close observation and follow up.</p> <p>Conclusion</p> <p>This study found that TB control is generally acceptabl in Taiwan; however, delayed treatment increases the risk of transmission. Improving the protocol for managing confirmed TB cases can minimize disease transmission.</p

National Mass Drug Administration Costs for Lymphatic Filariasis Elimination

Lymphatic filariasis (LF), commonly known as elephantiasis, is a profoundly disfiguring parasitic disease caused by thread-like nematode worms. This disease can often be disabling, thus reducing the potential productivity of the affected individuals. The WHO places the number of people at risk in 83 countries at 1.307 billion. This study was undertaken in seven countries—Burkina Faso, Ghana, Egypt, Tanzania, the Philippines, the Dominican Republic, and Haiti—using a common protocol to determine the costs of mass drug administration (MDA) programs to interrupt transmission of infection with LF, because there is lack of sufficient information about the costs of these programs. The results demonstrate that LF MDA is affordable and relatively inexpensive when compared to other public health programs. In the context of initiatives for integrating programs for the control and elimination of neglected tropical diseases, this study adds specifically to the relatively scarce body of information about the costs of MDA programs for LF. It also adds to the general knowledge about the application of methods that can be used to estimate the costs and cost-effectiveness of an integrated approach

Development of an In Vitro Compartmentalization Screen for High-Throughput Directed Evolution of [FeFe] Hydrogenases

BACKGROUND: [FeFe] hydrogenase enzymes catalyze the formation and dissociation of molecular hydrogen with the help of a complex prosthetic group composed of common elements. The development of energy conversion technologies based on these renewable catalysts has been hindered by their extreme oxygen sensitivity. Attempts to improve the enzymes by directed evolution have failed for want of a screening platform capable of throughputs high enough to adequately sample heavily mutated DNA libraries. In vitro compartmentalization (IVC) is a powerful method capable of screening for multiple-turnover enzymatic activity at very high throughputs. Recent advances have allowed [FeFe] hydrogenases to be expressed and activated in the cell-free protein synthesis reactions on which IVC is based; however, IVC is a demanding technique with which many enzymes have proven incompatible. METHODOLOGY/PRINCIPAL FINDINGS: Here we describe an extremely high-throughput IVC screen for oxygen-tolerant [FeFe] hydrogenases. We demonstrate that the [FeFe] hydrogenase CpI can be expressed and activated within emulsion droplets, and identify a fluorogenic substrate that links activity after oxygen exposure to the generation of a fluorescent signal. We present a screening protocol in which attachment of mutant genes and the proteins they encode to the surfaces of microbeads is followed by three separate emulsion steps for amplification, expression, and evaluation of hydrogenase mutants. We show that beads displaying active hydrogenase can be isolated by fluorescence-activated cell-sorting, and we use the method to enrich such beads from a mock library. CONCLUSIONS/SIGNIFICANCE: [FeFe] hydrogenases are the most complex enzymes to be produced by cell-free protein synthesis, and the most challenging targets to which IVC has yet been applied. The technique described here is an enabling step towards the development of biocatalysts for a biological hydrogen economy