J, Pramod M. P, Ramesh A, Murugesan R, Kumarasamy A. Simulation of a Diesel Engine with Variable Geometry Turbocharger and Parametric Study of Variable Vane Position on Engine Performance

Modelling of a turbocharger is of interest to the engine designer as the work developed by the turbine can be used to drive a compressor coupled to it. This positively influences charge air density and engine power to weight ratio. Variable geometry turbocharger (VGT) additionally has a controllable nozzle ring which is normally electro-pneumatically actuated. This additional degree of freedom offers efficient matching of the effective turbine area for a wide range of engine mass flow rates. Closing of the nozzle ring (vanes tangential to rotor) result in more turbine work and deliver higher boost pressure but it also increases the back pressure on the engine induced by reduced turbine effective area. This adversely affects the net engine torque as the pumping work required increases. Hence, the optimum vane position for a given engine operating point is to be found through simulations or experimentation. A thermodynamic simulation model of a 2.2l 4 cylinder diesel engine was developed for investigation of different control strategies. Model features map based performance prediction of the VGT. Performance of the engine was simulated for steady state operation and validated with experimentation. The results of the parametric study of VGT’s vane position on the engine performance are discussed.

P, Ramesh A, Thomas AM, Ramanujachari V, Murugesan R, Kumarasamy A. Development and Demonstration of Control Strategies for a Common Rail Direct Injection Armoured Fighting Vehicle Engine

<p class="Abstract">The development of a controller which can be used for engines used in armoured fighting vehicles is discussed. This involved choosing a state of the art reference common rail automotive Diesel engine and setting-up of a transient engine testing facility. The dynamometer through special real-time software was controlled to vary the engine speed and throttle position. The reference engine was first tested with its stock ECU and its bounds of operation were identified. Several software modules were developed in-house in stages and evaluated on special test benches before being integrated and tested on the reference engine. Complete engine control software was thus developed in Simulink and flashed on to an open engine controller which was then interfaced with the engine. The developed control software includes strategies for closed loop control of fuel rail pressure, boost pressure, idle speed, coolant temperature based engine de-rating, control of fuel injection timing, duration and number of injections per cycle based on engine speed and driver input. The developed control algorithms also facilitated online calibration of engine maps and manual over-ride and control of engine parameters whenever required. The software was further tuned under transient conditions on the actual engine for close control of various parameters including rail pressure, idling speed and boost pressure. Finally, the developed control strategies were successfully demonstrated and validated on the reference engine being loaded on customised transient cycles on the transient engine testing facility with inputs based on military driving conditions. The developed controller can be scaled up for armoured fighting vehicle engines.</p>

Basal cell carcinoma- a prospective clinico epidemiological and pathological study

Background: Basal cell carcinoma is the most common malignant tumour of the skin worldwide. The objective was to find out the age and sex incidence of basal cell carcinoma in patients attending the outpatient department of dermatology and to find out the various clinical and histopathological features of basal cell carcinoma.Methods: It was a prospective observational study carried out in a tertiary care hospital, Chennai, Tamilnadu, India. Patients with clinical diagnosis of basal cell carcinoma were included in the study after thorough history, clinical examination, routine and special investigations like skin biopsy.Results: Out of 20 patients with basal cell carcinoma 6 were males and 14 were females with a male to female ratio of 1:2.33. Most commonly affected age group was 50-70 years (70%). Distribution of BCC in our study was confined to head and neck area. Most common morphological subtype encountered in this study was nodular/nodulo-ulcerative BCC (70%), followed by pigmented type (25%) and superficial BCC (5%). The most common histological variant observed in present study was nodular type (55%), followed by pigmented variant (25%), adenoid (5%), basisquamous (5%), superficial BCC (5%) and BCC with sebaceous differentiation (5%).Conclusions: This study highlights a paradoxically increasing trend of BCC with female predilection. Early detection and treatment of lesions are crucial to decrease the functional and cosmetic disfigurement and also this study highlights the importance of improving awareness among general practitioners, public health workers and general population.

Healthcare waste disposal strategy selection using grey-AHP approach

Purpose

Nowadays healthcare waste (HCW) has become a big challenge for the hospital management, especially, in developing countries like India. Like other developing countries, Indian healthcare waste disposal (HCWD) industry is also fragmented, as some hospitals are having their own in-house waste treatment facilities and others are outsourcing the process to government authorized Common Biomedical Waste Treatment Facilities. Literature also lacks the quantitative studies in selecting the HCWD strategy and, hence, the purpose of this paper is to identify and prioritize the factors, which affect the selection of HCWD strategy and to propose the model to select the HCWD strategy and to apply the proposed model to select the HCWD strategy in Uttarakhand, Northern State of India.

Design/methodology/approach

Grey theory-based analytic hierarchy process approach has been applied to evaluate the HCWD options and select the appropriate strategy for the healthcare facilities (HCFs).

Findings

From the literature, six criteria have been used to evaluate the HCWD strategies: “access to expertise,” “overdependence,” “transportation & risk associated,” “Government rules,” “environmental factors,” and “economic factors.” “Outsourcing” strategic option (0.61) got the higher desirability index than “in-house treatment” (0.39).

Research limitations/implications

The proposed methodology can be used by the researchers and experts in the field to evaluate the strategic options and select the appropriate strategy.

Practical implications

The HCFs and other generators of HCW can select the alternative, whether they should treat the infectious waste in-house or they should go for outsourcing.

Originality/value

In the field of HCW management, this is the first study of its kind, which helps to evaluate and select the HCWD strategies. The proposed model has been applied in Uttarakhand, Northern State of India to make the comparison between “in-house” and “outsource” strategies.

Tuberculosis mimicking primary systemic vasculitis: not to be missed!

Infections are an important differential diagnosis in patients presenting with features of systemic vasculitis. We report a young lady with constitutional features, leg ulcers, digital gangrene and absent peripheral pulses with cervical adenopathy. Chest imaging revealed multiple necrotic lung lesions and involvement of left subclavian artery at its origin from the aorta, Histopathology from cervical lymph nodes showed multiple caseated lymph nodes, which in the context of a positive Mantoux test led us to diagnose tuberculosis and institute appropriate therapy. This is only the second report of tuberculosis presenting as peripheral gangrene, cutaneous ulcers and absent pulses, and serves to educate rheumatologists regarding the need to consider infections as mimics of vasculitis, especially in the developing countries.

Facile synthesis of uniformly dispersed ZnO nanoparticles on a polystyrene/rGO matrix and its superior electrical conductivity and photocurrent generation

Herein, a ZnO/PS/rGO composite was prepared via a simple reflex method and its microstructural and physical properties were characterized using XRD, SEM, HRTEM, TGA, FTIR, UV-visible, PL spectroscopy, PCTR and OCVD measurements.

Current trends in etiology, prognosis and therapeutic aspects of Parkinson's disease: a review

Parkinson's disease (PD) is a movement disorder, mainly affecting population consisting of the aged. PD occurs chiefly due to progressive loss of dopaminergic neurons in nigrostriatal pathway. Largely, PD patients suffer from non-motor symptoms, such as depression, anxiety, fatigue, and sleep disorders, that needs further investigation and addressing during PD research. Depression in PD is a predominant and complex symptom, and its pathology exists extrinsic to the nigrostriatal system. This disease can  ultimately be managed by a combination of regular physiotherapy and proper medication. Taking together the present scenario of PD, including the nature of disease, characteristics, treatment, diagnosis of the patients with PD, these outcomes were reviewed to be explored along with many speech-based solutions to PD in this study. This neurodegenerative disorder needs advancement in  research and development which  can help patients with PD to lead a normal life.

Protective effect of saffron (Crocus sativus L.) aqueous extract against genetic damage induced by anti-tumor agents in mice

The genotoxic potential of anti-tumor drugs limits their efficacy in the treatment of cancers. Since ancient times, saffron (dried stigmas of Crocus sativus L.) has been used as a spice and medicinal herb. Saffron is a rich source of carotenoids and is known for its anti-cancer and antitumor properties. The present study was designed to ascertain the chemoprotective potential of saffron against the genotoxicity of three well-known anti-tumor drugs-cisplatin (CIS), cyclophosphamide (CPH) and mitomycin C (MMC)-using comet assay. Three doses of saffron (20, 40 and 80 mg/kg b.w.) were orally administered to mice for five consecutive days prior to the administration of anti-tumor drugs under investigation. Pre-treatment with saffron significantly inhibited anti-tumor drugs induced cellular DNA damage (strand breaks) as revealed by decreased comet tail length, tail moment and percent DNA in the tail. These findings, together with our previous results, suggest a potential role for saffron as an anti-genotoxic, anti-oxidant and chemopreventive agent and could be used as an adjuvant in chemotherapeutic applications.

Macrodystrophia Lipomatosa: An Unusual Cause of Localized Gigantism

Macrodystrophia lipomatosa (MDL) is a rare congenital form of localized gigantism characterized by progressive overgrowth of all mesenchymal elements with a disproportionate increase in fibro adipose tissue. Here we report a case of 20 years old male who presented with history of painless gradual enlargement of entire left upper limb since childhood. Magnetic resonance imaging and histopathology confirmed the diagnosis of macrodystrophia lipomatosa. This condition has to be differentiated from other causes of localized gigantism, since these conditions differ in their course, prognosis, complications and treatment.

A randomized study of very low-dose factor VIII prophylaxis in severe haemophilia - A success story from a resource limited country

INTRODUCTION

Current factor prophylaxis strategy practised in developed countries is not feasible in resource constraint developing countries like India.

AIM

The aim of this study was to investigate the efficacy and safety of very low-dose factor prophylaxis in India.

METHODS

Children of 1-10 years of age with severe haemophilia were randomized to Prophylaxis group and Episodic (On demand) group. Children in prophylaxis group received very low-dose factor VIII (FVIII) concentrate, i.e. 10 units kg(-1) body weights on 2 days a week. Episodic group received factor concentrate in standard recommended doses. The study period was 11.5 months.

RESULTS

In total 21 children were enrolled in this study, 11 assigned to prophylaxis and 10 to episodic group. Children on prophylaxis had 11 joint bleeds in comparison to 57 joint bleeds in episodic group. Mean number of haemarthrosis per patient per month were 0.08 (0.08 ± 0.13) in prophylaxis group compared to 0.48 (0.48 ± 0.34) in episodic group (P < 0.05). Total FVIII consumption was 87.51 and 56.32 units kg(-1) month(-1) in prophylaxis and episodic group respectively (P = ns). Overall median hospital emergency visits were 1 day in prophylaxis group and 9 days in episodic group (P ≤ 0.05). Median days of absenteeism from school were 25 days in episodic group and 3 days in prophylaxis group (P < 0.05). No significant complications were noted in prophylaxis group and compliance was 98%.

CONCLUSION

To conclude, low-dose FVIII prophylaxis is cost effective, efficacious and a safe method of preventing joint bleeds and consequent joint damages.

Graphene decorated with Fe nanoclusters for improving the hydrogen sorption kinetics of MgH2 – experimental and theoretical evidence

Graphene decorated with Fe clusters is proposed to be a possible alternative catalyst for the hydrogenation and dehydrogenation reactions of MgH₂.

Healthcare waste management research: A structured analysis and review (2005-2014)

The importance of healthcare waste management in preserving the environment and protecting the public cannot be denied. Past research has dealt with various issues in healthcare waste management and disposal, which spreads over various journals, pipeline research disciplines and research communities. Hence, this article analyses this scattered knowledge in a systematic manner, considering the period between January 2005 and July 2014. The purpose of this study is to: (i) identify the trends in healthcare waste management literature regarding journals published; (ii) main topics of research in healthcare waste management; (iii) methodologies used in healthcare waste management research; (iv) areas most frequently researched by researchers; and (v) determine the scope of future research in healthcare waste management. To this end, the authors conducted a systematic review of 176 articles on healthcare waste management taken from the following eight esteemed journals: International Journal of Environmental Health Research, International Journal of Healthcare Quality Assurance, Journal of Environmental Management, Journal of Hazardous Material, Journal of Material Cycles and Waste Management, Resources, Conservations and Recycling, Waste Management, and Waste Management & Research. The authors have applied both quantitative and qualitative approaches for analysis, and results will be useful in the following ways: (i) results will show importance of healthcare waste management in healthcare operations; (ii) findings will give a comparative view of the various publications; (c) study will shed light on future research areas.