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Thin-walled square tubes are used as automotive vehicular crash structures since they can be easily constrained at the endpoints. These tubes are generally produced by costly extrusion process and special mold designs are required for making the same. This research work proposes a novel idea of making by folding thin metal sheets into square tubes that can be easily prepared, cost-effective and flexible in sectional shape. However, spot welding can be used to enhance the bending resistance and energy absorption. Bending collapse of tubes is one of the most important deformation mechanisms to be ascertained to ensure the safety of people or cargo under accidental crash events. Three-point bending tests are generally employed to investigate the bending characteristics and hence performed on plain folded and spot-welded fold tubes. Results revealed that spot-weld and number of turns have an important influence on the bending resistance of the folded tubes. The comparison between traditional tubes and welded tubes showed that the welded tubes outperform the traditional tubes in some aspects like minimizing the peak force and maximizing energy absorption. Adopting a number of turns further increased the bending resistance of the tubes compared with traditional square tubes.

Thin-walled square tubes have proven their energy-absorbing capability in the automotive industries for safety applications. Unfortunately, special mold designs are required while making these tubes through extrusion process. This fabrication technique is in lack of flexibility or leads to low cost-effectiveness. In place of the existing extruded square tubes, this paper presents a novel energy absorber by folding thin metal sheets into tubes that are easily fabricated and cost-effective. However, it is unsafe to use these folded tubes directly due to its global buckling failure with low-energy absorption. Therefore, methods to improve the energy absorption characteristics of thin-walled structures have become essential. Spot and continuous welding are the effective joining techniques which can be used to enhance the energy absorption. In order to test the suitability of these tubes for crashworthiness, quasi-static tests were performed using a universal testing machine. The energy absorption capacity of these welded folded tubes was analyzed and compared with traditional square tubes with the same mass to quantify the relative merits. It was found that spot welding leads to a reduction in peak force and continuous welding leads to a reduction in performance due to its global bending. The results showed that the initial peak force of spot-welded tube is 10–15% lower than the continuous weld and 20–25% lower compared to the extruded square tube. Finally, it was found that spot-welded tubes had more crush length than that of continuous and plain folded one which leads to an increase in energy absorption. The outcomes of the present study would facilitate the design of welded tubes with better energy absorption.

In this paper an attempt is made to study the chemical reaction and combined buoyancy effects of thermal and mass diffusion on MHD convective flow along an infinite vertical porous plate in the presence of Hall current with variable suction and radiation absorption. A uniform magnetic field is applied in a direction normal to the porous plate. The equations governing the fluid flow are solved using the perturbation technique and the expressions for the velocity, the temperature and the concentration distributions have been obtained. Dimensionless velocity, temperature and concentration profiles are displayed graphically for different values of the parameters entering into the problem have been investigated.

We consider the heat and mass transfer on MHD flow of an incompressible electrically conducting fluid through a porous medium between two vertical porous plates under the influence of uniform transverse magnetic field normal to the plates. The flow through porous medium is governed by Brinkman’s model for the momentum equation. The solutions of the governing equations are obtained for the velocity, temperature and concentration profiles with the help of regular perturbation technique. The effects of various parameters on the velocity, temperature and concentration are discussed with the graphs. The skin friction, Nusselt number and Sherwood number are also obtained.

The role of a combustion chamber in a turbocharger test rig is to generate the hot gas. The generated gas should be stable with uniform mass flow as well as required thermodynamic properties. It is done by using wide range of air-fuel (AF) ratio at constant pressure process like a fuel burner. Hence, it is required to design the combustion chamber with suitable empirically derived formulas during the preliminary design stage. Thus the present study addresses the design procedure involved in development of a combustion chamber for a test rig based on the required inlet mass flow rate and temperature for the test section. The reference characteristics (reference area and reference velocity) of the combustor are considered in calculating other dimensions of the combustor. Then, the design data obtained through the formula is validated through CFD (Computational Fluid Dynamics) simulation. The simulation results showed that, the total pressure drop across the combustor was 0.017 against the assumed ratio of 0.07 at the design stage. It means that the total pressure is almost recovered. The recirculation flow in primary zone and jets of corresponding secondary and dilution zones were also observed. The suggested design procedure can be used to design the combustor.

Purpose: Antivascular endothelial growth factor agents are increasingly used in diabetic macular oedema (DME); however, there are few studies exploring their use in DME in real-world settings. Methods: POLARIS was a noninterventional, multicentre study to monitor 12-month outcomes in patients starting ranibizumab treatment in routine practices. The primary outcome was mean change in visual acuity (VA) from baseline to month 12 (last observation carried forward approach). Other outcomes included mean change in central retinal thickness (CRT) and resource utilization. Visual acuity (VA) outcomes were also stratified by country, baseline visual acuity score (VAS), sex, age and injection frequency. Results: Outcomes were analysed from all treated patients (n = 804) and from first-year completers (patients who had a visual acuity assessment at 12 months; n = 568). The mean (SD) baseline VAS was 59.4 (15.9) letters, and the mean change in visual acuity was 4.4 letters (95% confidence interval: 3.3–5.4) at month 12 (study eye; first-year completers). The mean number of injections (study eye) was 4.9, and the mean number of all visits (any eye) was 10 (58% were injection visits) over 12 months (first-year completers). The mean (SD) baseline CRT was 410.6 (128.8) μm, and the mean change in CRT was −115.2 μm at month 12 (study eye; first-year completers). Visual acuity (VA) outcomes were generally comparable across most countries and subgroups and were greatest in patients with the lowest baseline VAS (≤60 letters). Conclusion: POLARIS showed that real-world outcomes in DME patients starting treatment with ranibizumab were lower than those observed in clinical studies, in spite of extensive monitoring. © 2018 The Authors. Acta Ophthalmologica published by John Wiley & Sons Ltd on behalf of Acta Ophthalmologica Scandinavica Foundation.

Hall Effects on Hydromagnetic Channel Flow under an Inclined Magnetic Field

MHD Flow in a Channel with Wavy Porous Boundary

HALL EFFECTS ON UNSTEADY MHD FREE AND FORCED CONVECTION FLOW IN A POROUS ROTATING CHANNEL

One of the most intriguing phenomena observed during adriamycin (ADR) toxicity has been attributed to ADR-induced oxidative stress. The study was aimed to assess the protective effect of lipoic acid (LA) against ADR induced damage to erythrocytes. Male albino rats (Wistar strain) were subjected to ADR (1 mg/kg body weight/day i.v.) once a week for a period of 12 weeks. Haematological indices like haemoglobin levels (Hb) and haematocrit (Ht) were also lowered along with a marked increase in the activities of serum glutamate pyruvate transaminase (SGPT) and serum glutamate oxaloacetate transaminase (SGOT). These rats demonstrated enhanced erythrocyte membrane lipid peroxidation (LPO) and an onslaught in the antioxidant defence armoury, witnessed by lowered activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), vitamin A, vitamin C and vitamin E. Rats administered with ADR showed a marked decline in the activities of membrane-bound ATPases. Abnormal LPO and decreased deformability led to increased osmotic fragility of the red blood cells. Pretreatment with LA (35 mg/kg body weight/day i.p.) 24 hours prior to the administration of ADR once a week for a period of 12 weeks was effective in counteracting these biochemical disturbances, thereby minimizing the toxic side effects of ADR.

One of the most intriguing phenomenon observed during lead toxicity has been attributed to lead-induced oxidative stress. The combined effect of DL-a-lipoic acid (LA) and meso 2,3-dimercaptosuccinic acid (DMSA) on lead-induced alterations in selected parameters, which are indicators of oxidative stress in erythrocytes, have been studied. Lead acetate (Pb, 0.2%) was administered in drinking water for 5 weeks to induce toxicity. LA (25 mg/ kg body weight per day i.p.) and DMSA (20 mg/kg body weight per day i.p.) were administered individually and also in combination during week 6. Clinical evidence of toxic exposure was evident from the elevated blood lead levels (BPb) along with lowered levels of haemoglobin (Hb) and haematocrit (Ht). Lead-exposed animals showed enhanced membrane lipid peroxidation (LPO) in the erythrocytes. Damage to the erythrocyte membrane was evident from the decline in the activities of the trans-membrane enzymes, viz., Na1, K1 ATPase, Ca21 ATPase and Mg21 ATPase. Lead-exposed rats also suffered an onslaught on the antioxidant defence system witnessed by lowered activities of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) and reduced glutathione (GSH). Serum glutamic-oxoloacetic transaminase (SGOT) and serum glutamic-pyruvic transaminase (SGPT) were also elevated in lead-exposed rats. Treatment with either LA or DMSA reversed the lead-induced biochemical disturbances encountered by the erythrocytes, but combined treatment with LA and DMSA was very effective in mitigating all the parameters indicative of oxidative stress.

The deleterious effect of lead has been attributed to lead-induced oxidative stress with the consequence of lipid peroxidation. The present study was designed to investigate the combined effect of DL-alpha-lipoic acid (LA) and meso-2,3-dimercaptosuccinic acid (DMSA) on lead-induced peroxidative damages in rat kidney. The increase in peroxidated lipids in lead-poisoned rats was accompanied by alterations in antioxidant defence systems. Lead acetate (Pb, 0.2%) was administered in drinking water for 5 weeks to induce lead toxicity. LA (25 mg/kg body weight per day i.p.) and DMSA (20 mg/kg body weight per day i.p.) were administered individually and also in combination during the sixth week. Nephrotoxic damage was evident from decreases in the activities of gamma-glutamyl transferase and N-acetyl beta- D-glucosaminidase, which were reversed upon combined treatment with LA and DMSA. Rats subjected to lead intoxication showed a decline in the thiol capacity of the cell, accompanied by high malondialdehyde levels along with lowered activities of catalase, superoxide dismutase, glutathione peroxidase and glutathione metabolizing enzymes (glutathione reductase, glucose-6-phosphate dehydrogenase, glutathione- S-transferase). Supplementation with LA as a sole agent showed considerable changes over oxidative stress parameters. The study has highlighted the combined effect of both drugs as being more effective in reversing oxidative damage by bringing about an improvement in the reductive status of the cell.

Molecular-dynamics simulations of a model dipolar system containing two ions have been carried out to study the effect of temperature on the time-dependent friction (ζ(t)) on the solute ions as well as the electric fields in the vicinity of the ions. It is found that with an increase in temperature, (i) the magnitude of ζ (0) increases and (ii) the electric field time correlation functions decay more rapidly at higher temperatures due to faster reorientations and translational diffusion of the molecules. The effects of the size of the system on these properties have also been investigated.

Oxidative stress with subsequent lipid peroxidation has been postulated as one mechanism for lead toxicity. Hence in assessing the protective effects of lipoic acid (LA) and meso 2,3-dimercaptosuccinic acid (DMSA) on lead toxicity, they were tested either separately or in combination for their effects on selected indices of hepatic oxidative stress. Elevated levels of lipid peroxides were accompanied by altered antioxidant defense systems. Lead acetate (Pb - 0.2%) was administered in drinking water for five weeks to induce toxicity. LA (25 mg kg−1 body wt. day−1 i.p) and DMSA (20 mg kg−1 body wt. day−1 i.p) were administered individually and also in combination during the sixth week. Lead damage to the liver was evident in the decreases in hepatic enzymes alanine transaminase (−38%), aspartate transaminase (−42%) and alkaline phosphatase (−43%); increases in lipid peroxidation (+38%); decreases in the antioxidant enzymes catalase (−45%), superoxide dismutase (−40%), glutathione peroxidase (−46%) and decreases in glutathione (−43%) and decreases in glutathione metabolizing enzymes, glutathione reductase (−59%), glucose-6-phosphate dehydrogenase (−27%) and glutathione-S-transferase (−42%). In combination LA and DMSA completely ameliorated the lead induced oxidative damage. Either compound alone was however only partially protective against lead damage.

Adriamycin (ADR), which is widely used in the treatment of various neoplastic conditions, exerts toxic effects in many organs. The present study was designed to investigate the effect of lipoic acid (LA) against acute ADR induced peroxidative damages in rat kidney. The study was carried out with adult male albino rats of Wistar strain, which comprised of one control and three experimental groups. Group I rats served as controls. Group II rats received ADR (7.5mg/kg body weight) intravenously through the tail vein. Group III rats were given LA (75 mg/kg body weight) intraperitoneally. Group IV rats were given LA one day before the administration of ADR. Rats subjected to ADR administration showed a decline in the thiol capacity of the cell accompanied by high malondialdehyde (MDA) levels along with lowered activities of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) glutathione (GSH) and GSH metabolizing enzymes (glutathione reductase (GR), glucose-6-phosphate dehydrogenase (G6PD)). However no significant change was observed in the activity of glutathione-S-transferees (GST). Pretreatment with LA showed considerable changes over oxidative stress parameters. Nephrotoxic damage was evident from the decrease in the activities of gamma-glutamyl transferase (gamma-GT) and beta-glucuronidase (beta-GLU), which were reverted upon LA pretreatment.This study has highlighted the beneficial effects of LA pretreatment in reversing the damages caused by ADR, by bringing about an improvement in the reductive status of the cell.

Fungemia is a rare complication of Sporothrix schenckii infection and has always been associated with disseminated sporotrichosis. We describe an immunocompetent patient with localized lymphocutaneous sporotrichosis from whose blood the fungus was isolated. A lysis-centrifugation blood culture system may have improved our ability to detect low-level S. schenckii fungemia.