Application of evolutionary algorithms to optimize cooling channels

The design and development is a complex, repetitive, and more often difficult task, as design tasks comprising of restraining and conflicting relationships among design variables with more than one design objectives. Conventional methods for solving more than one objective optimization problems is to build one composite function by scalarizing the multiple objective functions into a single objective function with one solution. But, the disadvantages of conventional methods inspired scientists and engineers to look for different methods that result in more than one design solutions, also known as Pareto optimal solutions instead of one single solution. Furthermore, these methods not only involved in the optimization of more than one objectives concurrently but also optimize the objectives which are conflicting in nature, where optimizing one or more objective affects the outcome of other objectives negatively. This study demonstrates a nature-based and bio-inspired evolutionary simulation method that addresses the disadvantages of current methods in the application of design optimization. As an example, in this research, we chose to optimize the periodic segment of the cooling passage of an industrial gas turbine blade comprising of ribs (also known as turbulators) to enhance the cooling effectiveness. The outlined design optimization method provides a set of tradeoff designs to pick from depending on designer requirements

High Biomass Sorghum as a Potential Raw Material for Biohydrogen Production: A Preliminary Evaluation

Six high biomass sorghum lines (IS 22868, IS 27206, IS 15957, IS 16529, ICSV 93046 and CSH 22SS were evaluated for their potential as a substrate material for biohydrogen production by anaerobic fermentation using methanogens deactivated cow dung based mixed microbial consortia. The data revealed that all selected high biomass sorghum lines differed significantly for candidate biomass traits as well as for biomass composition. The high biomass lines, IS 27206 and IS 22868 recorded higher stalk and stover yield compared to others. Least biomass yield (stalk and stover) was noticed with ICSV 93046. The lignin content is low in IS 27206 and IS 15957. Highest biohydrogen yield was observed in IS 27206 followed by IS 22868 and ICSV 93046. The lignin content is negatively correlated with biohydrogen production

Sweet sorghum juice as an alternate substrate for fermentative hydrogen production: Evaluation of influencing parameters using DOE statistical approach

Biohydrogen production using agro-industrial by-products has considerable practical importance. Sweet sorghum is an ideal feedstock for biofuel production in the semi-arid and arid climatic regions. In the present investigation, the juice of SSV 74, a sweet sorghum variety, was examined as a novel substrate for biohydrogen production. The impact of medium pH, substrate, inoculum level and incubation temperature were analyzed at individual and interactive levels on biohydrogen production. Substrate level concentration and pH of the fermentation medium played a critical role on overall biohydrogen production at individual level, and indicated >90 % influence on product yield. On the other hand at interactive level; pH of the fermentation medium, inoculum and substrate concentrations revealed maximum severity index of 78 % (43 % for medium pH vs inoculum concentration and 35 % for inoculum vs substrate concentration). Overall, biohydrogen production yield was enhanced from 283 to 546 mL/3.25 g glucose equivalents of juice upon statistical optimization leading to a >190 % of H2 yield. Along with the H2 production, various acid intermediates were produced with acetate in maximum concentration indicating the occurence of acetogenic fermentatio

Fermentation of Pretreated High-Biomass Sorghum Hydrolysates to Biohydrogen by Mixed Consortia

In the present study, hydrolysate generated during pretreatment of high-biomass sorghum as a carbon source for biohydrogen production was investigated. The high-biomass sorghum bagasse (HBS) was pretreated using acid (H2SO4) and alkali (NaOH) at various concentrations (0.5–5 % w/v) for the residence time of 30 min at 121 °C, 15 lbs pressure at 10 % (w/v) solid loading. At the optimal acid load of 2 % (w/v) H2SO4 yielded 78.0 g COD/L of hydrolysate. The hydrolysate generated during this pretreatment was analyzed and noticed to contain glucose 10 g L−1, xylose 23 g L−1, arabinose 2.0 g L−1, HMF 1.9 g L−1, furfural 3.5 g−1, acetic acid 9.3 g L−1, formic acid 5.0 g L−1, and phenols 1.9 g L−1. The fermentation studies were conducted in dark conditions using all the hydrolysates by heat-treated mixed microbial consortia. Maximum H2 production rate (HPR), cumulative H2 production (CHP), and specific H2 yield (SHY) were measured. Maximum CHP (328 mL) and SHY (4.68 mol/kg CODr) were registered with acid treatment-resulted hydrolysate, and volatile fatty acid analysis indicated higher acetic acid concentration (1.6 g L−1) showing acidogenic microenvironment directing fermentation toward acetate pathway. The present study assumes importance in safe disposal and simultaneous production of value-added byproducts during lignocellulosic biorefinery. Fermentation of Pretreated High-Biomass Sorghum Hydrolysates to Biohydrogen by Mixed Consortia

Catecholaminergic signalling through thymic nerve fibres, thymocytes and stromal cells is dependent on both circulating and locally synthesized glucocorticoids

Glucocorticoids have been shown to modulate the expression of noradrenaline metabolizing enzymes and beta(2)- and alpha(1B)-adrenoceptors in a tissue- and cell- specific manner. In the thymus, apart from extensive sympathetic innervation, a regulatory network has been identified that encompasses catecholamine-containing non-lymphoid and lymphoid cells. We examined a putative role of adrenal- and thymus-derived glucocorticoids in modulation of rat thymic noradrenaline levels and adrenoceptor expression. Seven days postadrenalectomy, the thymic levels of mRNAs encoding tyrosine hydroxylase, dopamine beta-hydroxylase, monoamine oxidase-A and, consequently, noradrenaline were decreased. Catecholamine content was diminished in autofluorescent nerve fibres (judging by the intensity of fluorescence) and thymocytes (considering HPLC measurements of noradrenaline and the frequency of tyrosine hydroxylase-positive cells), while it remained unaltered in non-lymphoid autofluorescent cells. In addition, adrenalectomy diminished the thymocyte expression of beta(2)- and alpha(1B)-adrenoceptors at both mRNA and protein levels. Administration of ketoconazole (an inhibitor of glucocorticoid synthesis/action; 25 mg kg(-1) day(-1), s.c.) to glucocorticoid-deprived rats increased the thymic levels of tyrosine hydroxylase, dopamine beta-hydroxylase and, consequently, noradrenaline. The increased intensity of the autofluorescent cell fluorescence in ketoconazole-treated rats indicated an increase in their catecholamine content, and suggested differential glucocorticoid-mediated regulation of catecholamines in thymic lymphoid and non-lymphoid cells. In addition, ketoconazole increased the thymocyte expression of alpha(1B)-adrenoceptors. Thus, this study indicates that in the thymus, as in some other tissues, glucocorticoids not only act in concert with cateholamines, but they may modulate catecholamine action by tuning thymic catecholamine metabolism and adrenoceptor expression in a cell-specific manner. Additionally, the study indicates a role of thymus-derived glucocorticoids in this modulation

Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

Evolutionary numerical simulation approach for design optimization of gas turbine blade cooling channels

Gas turbine blade cooling system design is a multidisciplinary, iterative and often tedious task involving complex relationships among multiple design objectives. Typical blade design requires a broad range of expertise in the materials, structural, heat transfer, and cost optimization disciplines. The multiple objectives involved are often conflicting and must be solved simultaneously with equal importance. The traditional approaches researchers scalarize the multiple objectives into a single objective using a weight vector, thus transforming the original multiple objective problem into a single objective problem. This research addresses the shortcomings of existing traditional approaches of the optimization of blade cooling configuration design