Technologies for High Power Density Diesel Engines

The engines used in armoured fighting vehicles have to be compact, light in weight, efficient and reliable. In order to achieve a compact engine design, a complete understanding of all the factors affecting the engine performance is needed. However, it is important to note that the performance of the engine cannot be compromised in the pursuit of compactness. The aim of this paper is to classify systematically various broad areas affecting the engine’s power to weight and power to volume ratio and discuss respective current technologies available. This paper explores the possibility of size and weight reduction and efficiency enhancement of diesel engines by the use of various methods like engine friction reduction, better thermal management, high injection pressure, and turbocharging. Achieving high engine speeds and high BMEP will be the means of achieving high power density. The effects of engine configuration and technologies on compactness are also discussed. Finally, the configuration of a new engine and its design aspects, incorporating all the aforementioned concepts is discusse

Potable Water Identification with Machine Learning: An Exploration of Water Quality Parameters

In this research, we aim to determine the water potability using three machine learning classification algorithms: decision tree, gradient boosting and bagging classifier. These algorithms were trained and tested on a dataset of water quality measurements. The outcomes of the experiment showed that the gradient boosting algorithm achieved the highest F1-score of 0.78 among all the algorithms. This indicates that the gradient boosting algorithm was most effective in correctly identifying both the safe and contaminated water samples. The results of this study demonstrate that gradient boosting is a promising approach for determining water potability and can be used as a reliable method for water quality assessment

Development of a Fuel Quantity based Engine Control Unit Software Architecture

   Conventionally diesel engines are controlled in open loop with maps based on engine speed and throttle position wherein fuel quantity is indirectly fixed using the rail pressure and injection duration maps with engine speed and throttle position as the independent variables which are measured by the respective sensors. In this work an engine control unit (ECU) software architecture where fuel quantity is directly specified in relation to the driver demand was implemented by modifying the control logic of a throttle position based framework. A desired fuel quantity for a given engine speed and throttle position was mapped from base line experiments on the reference engine. Injection durations and rail pressure required for this quantity was mapped on a fuel injector calibration test bench. The final calculation of injection duration in the new architecture is calculated using the fuel injector model. This enables determination of fuel quantity injected at any moment which directly indicates the torque produced by the engine at a given speed enabling smoke limited fuelling calculations and easing the implementation of control functions like all-speed governing

Switching to second-line antiretroviral therapy in resource-limited settings: comparison of programmes with and without viral load monitoring.

In high-income countries, viral load is routinely measured to detect failure of antiretroviral therapy (ART) and guide switching to second-line ART. Viral load monitoring is not generally available in resource-limited settings. We examined switching from nonnucleoside reverse transcriptase inhibitor (NNRTI)-based first-line regimens to protease inhibitor-based regimens in Africa, South America and Asia

Prioritising prevention strategies for patients in antiretroviral treatment programmes in resource-limited settings

Expanded access to antiretroviral therapy (ART) offers opportunities to strengthen HIV prevention in resource-limited settings. We invited 27 ART programmes from urban settings in Africa, Asia and South America to participate in a survey, with the aim to examine what preventive services had been integrated in ART programmes. Twenty-two programmes participated; eight (36%) from South Africa, two from Brazil, two from Zambia and one each from Argentina, India, Thailand, Botswana, Ivory Coast, Malawi, Morocco, Uganda and Zimbabwe and one occupational programme of a brewery company included five countries (Nigeria, Republic of Congo, Democratic Republic of Congo, Rwanda and Burundi). Twenty-one sites (96%) provided health education and social support, and 18 (82%) provided HIV testing and counselling. All sites encouraged disclosure of HIV infection to spouses and partners, but only 11 (50%) had a protocol for partner notification. Twenty-one sites (96%) supplied male condoms, seven (32%) female condoms and 20 (91%) provided prophylactic ART for the prevention of mother-to child transmission. Seven sites (33%) regularly screened for sexually transmitted infections (STI). Twelve sites (55%) were involved in activities aimed at women or adolescents, and 10 sites (46%) in activities aimed at serodiscordant couples. Stigma and discrimination, gender roles and funding constraints were perceived as the main obstacles to effective prevention in ART programmes. We conclude that preventive services in ART programmes in lower income countries focus on health education and the provision of social support and male condoms. Strategies that might be equally or more important in this setting, including partner notification, prompt diagnosis and treatment of STI and reduction of stigma in the community, have not been implemented widely

The WHO global tuberculosis 2021 report - not so good news and turning the tide back to end TB

Objective: To review the data presented in the 2021 WHO global TB report and discuss the current constraints in the global response. Introduction and methods: The WHO global TB reports, consolidate TB data from countries and provide up to date assessment of the global TB epidemic. We reviewed the data presented in the 2021 report. Results: We noted that the 2021 WHO global TB report presents a rather grim picture on the trajectory of the global epidemic of TB including a stagnation in the annual decline in TB incidence, a decline in TB notifications and an increase in estimated TB deaths. All the targets set at the 2018 United Nations High Level Meeting on TB were off track. Interpretation and conclusion: The sub-optimal global performance on achieving TB control targets in 2020 is attributed to the on-going COVID-19 pandemic, however, TB programs were already off track well before the onset of the pandemic, suggesting that the pandemic amplified an already fragile global TB response. We emphasize that ending the global TB epidemic will require bold leadership, optimization of existing interventions, widespread coverage, addressing social determinants of TB and importantly mobilization of adequate funding required for TB care and preventio

EFFECT OF THE NITRATE FERTILIZER UREA ON THE ULTRASTRUCTURAL CHANGES IN THE GILL OF FRESHWATER FISH CATLA

Ultrastructural study of the gill of Catla catla on exposure to 10% LC 50 sublethal concentration of nitrate fertilizer urea was carried out. Hypertrophy and hyperplasia of the lamellar cells in combination with epithelial lifting and edema were noticed. Necrosis of pillar system with lamella resulted in blood congestion and even an aneurism. Hyper secretion of mucous on the epithelium is to protect against environmental alteration was also determined. Infiltrated macrophages and leucocytes in the lamellar tissue were observed which was a compensatory repair response to tissue damages. Apoptotic condition of the cell is evident by clumping of chromatin, swelling of nucleus and mitochondria