CFD Simulation of a Co-Current Spray Dryer for Silica Powder Production

Abstract: This paper presents the prediction of air flow, temperature patterns and mass fraction of water vapour in a co current pilot plant spray dryer fitted with pressure swirl nozzle using 3 dimensional model. The modeling was done with CFD package star ccm+ 9.04, in which the droplet/particle phase is modeled with Langrangian approach and hot air stream is modeled with Euler approach, K-ԑ model is used to analysis the turbulence swirl in the spray dryer. Good results were obtained with the modified balanced double tangential air inlets spray dryer when compared with the conventional single tangential air inlet spray dryer . the problem of stick of the wet particles on the walls of the spray dryer and cone part of the spray dryer was eliminated in the modified model. A higher uniformity of temperature and air mass fraction on the horizontal planes of the spray dryer were obtained by the modified design of the spray dryer. This work was carried with multiphase flow and the feed considered for the work is silica slurry (40% Si, 60%liquid water) for the analysis.In this work the effects of the air flow pattern on the droplets trajectory, residence time, distribution of droplets, and the deposition of droplets on the wall were compared with the conventional model and the modified air inlet design model

Medical termination of pregnancy and subsequent adoption of contraception

Background: The reasons for seeking MTP ranged from proximate causes such as desire to limit family size or space pregnancies, seeking abortion for medical reasons or availing it on medical advice to distal determinants such as poverty, violence and belief system. Therefore, the present study was undertaken to study the factors influencing MTPs & the subsequent adoption of contraceptive methods following MTP.Methods: The study subjects included women who underwent MTP at the hospital during the study period. The details regarding their socio demographic profile, previous obstetric history, reason for seeking abortion and acceptance of post abortal contraception were taken.Results: 103 women who sought MTP during the study period were included in the study. Among the MTP seekers 22 (21.4%) women had history of one or more abortions in the recent past. Most of the study subjects i.e., 41 (39.8%) sought MTP for socio-economic reasons. The other conditions were eugenic reasons among 40 (38.9%) and medical reasons 10 (9.1%), only 12 (11.6%) women sought MTP for contraceptive failure. Adoption of contraception following MTP was seen only among 52 (50.5%).Conclusions: Eligible couples have to be educated regarding the availability of different methods of contraceptives and their proper use to avoid pregnancy as long as they want. Similarly, all MTP seekers should be provided information and counseling for post-abortal contraceptive use and enable these women and their spouse to make an informed and voluntary choice and thus avoid the need of a repeat abortion.

Microstructure and optical appearance of anodized friction stir processed Al - Metal oxide surface composites

Multiple-pass friction stir processing (FSP) was employed to impregnate Ti, Y and Ce oxide powders into the surface of an Aluminium alloy. The FSP processed surface composite was subsequently anodized with an aim to develop optical effects in the anodized layer owing to the presence of incorporated oxide particles which will influence the scattering of light. This paper presents the investigations on relation between microstructure of the FSP zone and optical appearance of the anodized layer due to incorporation of metal oxide particles and modification of the oxide particles due to the anodizing process. The effect of anodizing parameters on the optical appearance of the anodized surface was studied. Characterization was performed using SEM, FIB-SEM, TEM and GI-XRD. The surface appearance was analysed using photospectrometry technique which measures the diffuse and total reflectance of the surface. The appearance of the anodized surface changed from dark to bright upon increasing the anodizing voltage. Particles in the FSP zone were partially or completely modified during the anodizing process and modified the morphology of the surrounding anodized Al matrix which has a clear influence on the mechanism of light interaction like scattering and absorption from the anodized surface

Investigation of DC magnetron-sputtered TiO2 coatings: Effect of coating thickness, structure, and morphology on photocatalytic activity

The photocatalytic performance of magnetron-sputtered titanium dioxide (TiO2) coatings of different thickness in anatase crystalline structure deposited on aluminium 1050 alloy substrates was investigated using a combination of photo-electrochemistry, methylene blue decomposition, and microscopic and spectroscopic methods, such as high resolution scanning and transmission electron microscopy, atomic force microscopy and ellipsometry. The reaction resistance was measured by AC impedance, while photocurrent measurements were carried out using the zero resistance ammetry (ZRA) method. The results showed that the TiO2 grains grow in dipyramidal columns having a linear increase in surface area with increased coating thickness. The refractive index values indicate also an evolutionary growth.The refractive index values obtained for the thin coatings on aluminium substrate were well below the values reported for monocrystalline anatase. The photocatalytic performance increased with increased coating thickness, though more rapidly over a range of 100 - 500 nm thickness. The dielectric constant also increased linearly with coating thickness.<br/

Effects of Diesel Combustion Nanoparticles on Oxidative Stress Markers among the Exposures

Background: Although studies are available on lipid peroxidation products and the antioxidant status in experimental animals, a detailed report on human exposed to diesel combustion nanoparticles is meagre. We aimed to study the variation in oxidative stress markers among exposures. Method:A cross-sectional study during the period between 2015-2017 was conducted among 500 male garage workers of age group 25-40 years with history of exposure for 6-8 hrs a day without using any protective aids during work, for 6-12 years and 300 controls, who live in hilly areas where they were sparsely exposed. Serum oxidative stress markers were estimated and compared.  Results:A significant variation was observed among the oxidative stress markers in exposures with surge in melanaldehyde (MDA) and reduction in superoxide dismutase (SOD) and catalase (CAT). Conclusion:Unprotected exposure to diesel combustion products induces oxidative stress which can alter recordable change among the markers. Oxidative stress, being the route cause for cell damage, can be marked in the initial stages and is a good biomonitoring factor in primary care

Intracellular activation of EGFR by fatty acid synthase dependent palmitoylation

Epidermal growth factor receptor (EGFR) is an oncogenic receptor tyrosine kinase. Canonically, the tyrosine kinase activity of EGFR is regulated by its extracellular ligands. However, ligand-independent activation of EGFR exists in certain cancer cells, and the underlying mechanism remains to be defined. In this study, using PC3 and A549 cells as a model, we have found that, in the absence of extracellular ligands, a subpopulation of EGFR is constitutively active, which is needed for maintaining cell proliferation. Furthermore, we have found that fatty acid synthase (FASN)-dependent palmitoylation of EGFR is required for EGFR dimerization and kinase activation. Inhibition of FASN or palmitoyl acyltransferases reduced the activity and down-regulated the levels of EGFR, and sensitized cancer cells to EGFR tyrosine kinase inhibitors. It is concluded that EGFR can be activated intracellularly by FASN-dependent palmitoylation. This mechanism may serve as a new target for improving EGFR-based cancer therapy

Alleviation of Multinutrient Deficiency for Productivity Enhancement of Rain-Fed Soybean and Finger Millet in the Semi-arid Region of India

Soil nutrient contents were determined in 802 surface soil samples (0–15 cm deep) collected from farmers' fields that support extensive cultivation of soybean (Glycine max L.) and finger millet (Eleusine coracana G.), spread across three districts, in the semi-arid regions of Karnataka, India. Following soil analysis, on-farm crop trials were conducted during 2005–2007 to study the crop response to the soil application of nitrogen (N), phosphorus (P), sulfur (S), boron (B), and zinc (Zn) fertilizers. Analyses of soil samples revealed that 4–83% fields were deficient in N, 34–65% in P, 83–93% in extractable S, 53–96% in B, and 34–88% of farmers' fields were deficient in Zn. On-farm trials conducted during the three rainy seasons (2005, 2006, and 2007) significantly (P ≤ 0.05) enhanced crop productivity indices such as yields of grain, stover, and total biomass in soybean and finger millet crops. Integrated management of deficient nutrients in finger millet and soybean crops significantly enhanced the grain and straw uptake of N, P, K, S, and Zn

Mechanistic insight into acrylate metabolism and detoxification in marine dimethylsulfoniopropionate-catabolizing bacteria

Dimethylsulfoniopropionate (DMSP) cleavage, yielding dimethyl sulfide (DMS) and acrylate, provides vital carbon sources to marine bacteria, is a key component of the global sulfur cycle and effects atmospheric chemistry and potentially climate. Acrylate and its metabolite acryloyl-CoA are toxic if allowed to accumulate within cells. Thus, organisms cleaving DMSP require effective systems for both the utilization and detoxification of acrylate. Here, we examine the mechanism of acrylate utilization and detoxification in Roseobacters. We propose propionate-CoA ligase (PrpE) and acryloyl-CoA reductase (AcuI) as the key enzymes involved and through structural and mutagenesis analyses, provide explanations of their catalytic mechanisms. In most cases, DMSP lyases and DMSP demethylases (DmdAs) have low substrate affinities, but AcuIs have very high substrate affinities, suggesting that an effective detoxification system for acylate catabolism exists in DMSP-catabolizing Roseobacters. This study provides insight on acrylate metabolism and detoxification and a possible explanation for the high Km values that have been noted for some DMSP lyases. Since acrylate/acryloyl-CoA is probably produced by other metabolism, and AcuI and PrpE are conserved in many organisms across all domains of life, the detoxification system is likely relevant to many metabolic processes and environments beyond DMSP catabolism

Mechanistic insight into acrylate metabolism and detoxification in marine dimethylsulfoniopropionate-catabolizing bacteria

Dimethylsulfoniopropionate (DMSP) cleavage, yielding dimethyl sulfide (DMS) and acrylate, provides vital carbon sources to marine bacteria, is a key component of the global sulfur cycle and effects atmospheric chemistry and potentially climate. Acrylate and its metabolite acryloyl-CoA are toxic if allowed to accumulate within cells. Thus, organisms cleaving DMSP require effective systems for both the utilization and detoxification of acrylate. Here, we examine the mechanism of acrylate utilization and detoxification in Roseobacters. We propose propionate-CoA ligase (PrpE) and acryloyl-CoA reductase (AcuI) as the key enzymes involved and through structural and mutagenesis analyses, provide explanations of their catalytic mechanisms. In most cases, DMSP lyases and DMSP demethylases (DmdAs) have low substrate affinities, but AcuIs have very high substrate affinities, suggesting that an effective detoxification system for acylate catabolism exists in DMSP-catabolizing Roseobacters. This study provides insight on acrylate metabolism and detoxification and a possible explanation for the high Km values that have been noted for some DMSP lyases. Since acrylate/acryloyl-CoA is probably produced by other metabolism, and AcuI and PrpE are conserved in many organisms across all domains of life, the detoxification system is likely relevant to many metabolic processes and environments beyond DMSP catabolism