272 research outputs found

    Nutritional Status of Adolescent Girls from Rural Communities of Tigray, Northern Ethiopia

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    Background: Addressing the nutritional needs of adolescents could be an important step towards breaking the vicious cycle of intergenerational malnutrition. Objective: Assess nutritional status of rural adolescent girls. Design: Cross-sectional. Methods: Anthropometric and socio-demographic information from 211 adolescent girls representing 650 randomly selected households from thirteen communities in Tigray was used in data analysis. Height-for-age and BMI-for-age were compared to the 2007 WHO growth reference. Data were analyzed using SAS, Version 9.1. Results: None of the households reported access to adolescent micronutrient supplementation. The girls were shorter and thinner than the 2007 WHO reference population. The cross-sectional prevalence of stunting and thinness were 26.5% and 58.3%, respectively. Lack of latrine facilities was significantly associated with stunting (p = 0.0033) and thinness (p <0.0001). Age was strong predictor of stunting (r(2) = 0.8838, p <0.0001) and thinness (r(2) = 0.3324, p <0.0001). Conclusion: Undernutrition was prevalent among the girls. Strategies to improve the nutritional status of girls need to go beyond the conventional maternal and child health care programs to reach girls before conception to break the intergenerational cycle of malnutrition. Further, carefully designed longitudinal studies are needed to identify the reasons for poor growth throughout the period of adolescence in this population. [Ethiop. J. Health Dev. 2009; 23(1):5-11

    Experiment of oxygenated fuel on diesel engine: Performance, emission and particulate matter

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    The main purpose of the study is to characterise the effects of diesel, biodiesel blends B5M10 and B10M10 and emulsion fuels B5M10E3 and B10M10E3 as fuels for the impact on particulate matter emission. Engine tests have been performed to obtain results of engine performance, gas emission and particulate matter with various cycles. Excel analysis methods were used to analysethe data obtained.The B5M10E3 produces lowe

    Effect Of Emulsification And Blending On The Oxygenation And Substitution Of Diesel Fuel For Compression Ignition Engine

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    Global emission standards are getting more stringent in which the existing diesel engine technologies are on the brink of losing their permit to operate. While there are successful engine side researches that can target the current emission norms, their implementation in existing engines will not be possible due to their higher price tag. With this respect, fuel side improvement with no or minimal modification to engine hardware is the best way to address the issue in the existing engines. The commonly used fuel oxygenators in diesel engines are water, alcohol, biodiesel and the combinations of these. The method of oxygenation and their corresponding results on the combustion, performance and emissions that have been reported in the literatures are widely varied. The current review article targets the blending and emulsification techniques used in the oxygenation and fuel substitution of diesel. Based on the misconceptions about the stability of emulsions, many researchers are found to use the term blending even though the technique they have used is emulsification. While blending of fuels is convenient for fuels which have relatively similar boiling temperature, emulsification technique should be followed for fuel mixtures of varied boiling temperature so that the benefit of micro-explosion can be reflected in the fuel atomization. Secondary atomization resulting from the micro-explosion phenomenon of emulsified fuels and fuel oxygenation are responsible for the improvement of combustion, performance and CO and PM emissions. Latent heat of vaporization is found to be responsible for the reduction of NOx emissions

    Invitro Antibacterial Screening of Extracts from Selected Ethiopian Medicinal Plants

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    Indigenous knowledge, literature reports and ethnobotanical records suggest that plants are the basis for medicines. They constitute natural source of antimicrobial drugs that will provide novel or lead compounds for the fight against disease. In this study, the antimicrobial activity of three selected Ethiopian medicinal plants was studied with the objective of  screening their antibacterial activity. The fruits of Measalanceolata, aerial part of Cissus quadrangularis and leaf of Dodonae angustifolia were collected, air dried under shed, powdered and soaked in 80% methanol and extracted. In vitro antibacterial activity of the extracts was tested at different concentrations by using agar disc diffusion method and  measuring the zone of inhibition. The plant extracts showed broad  spectrum activity against gram positive (S. aureus) as well as gram  negative (E. coli) bacteria, except Cissus quadrangularis which did not show any activity against E. coli. Furthermore, the plant extracts had also  concentration dependant zone of inhibition against the tested bacteria. In fact, the highest activity was obtained for Dodonae angustifolia at  1000mg/ml against S. aureus. The activities are attributed to the presence of some secondary metabolites present in the tested plants which have been associated with antibacterial activities. This finding suggests that these medicinal plants can be potential source to isolate antibacterial drugs.Keywords: Antibacterial activity, Disc diffusion, E. coli, Plant extract and S. aureus

    Diesel and various blending nanoparticles based diesel, fuel properties study

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    In recent years, many researches have been performed to find suitable alternative fuels to petroleum products. In the present investigation, an experimental work has been carried out to examine the fuel properties test for pure diesel, diesel blended with silicon oxide nano, diesel blended with titanium oxide nano and diesel blended with graphene nanoplate which are namely as D, DS5, DT5 and DG5 respectively. The results indicated that the pure diesel fuel density is higher than DT5 by about 1%. However, this value is reduced to about 1% for DG5 and DS5 respectively compared to diesel fuel due to the blending effects. Meanwhile, in calorific value test, DS5 fuel energy content is lower than diesel by about 1.5%. However, this value is reduced to about 1.43% and 1.37% for DG5 and DT5 respectively compared to diesel fuel due to the blending effects

    Investigation of the stability of cerium oxide in diesel fuel for nano-enhanced fuel formulation

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    Abstract. Enhancing fuels through nano-addition has become a prospect in keeping both renewable and non-renewable fuels as energy sources for the transportation sector. One of the challenges when using nanofluids in a specific system is the fluid’s ability to be stable for a longer period. Undesired settlement of nanoparticles can cause damage to the system operating within its limits due to contamination, therefore stability study has paramount importance in the nano-enhanced fuel introduction in internal combustion engines. checking nanofluid stabilization consider a challenge since it takes time and it has tendency to aggregate in certain time, therefore UV vis device was a perfect tool to investigate the stability of the nano fuel. Three-step method using UV-Vis spectral absorbency device was selected to measure the nanofluid and ensure the stability of the solution daily. Cerium oxides consider one of the challenging nano additives to blend with fuel. To measure its stability, it was observed that when the nanofluid fuel was mixed with nanoparticles in quantities estimated at 25, 50, and 75 ppm, the nano fuel solution showed a high stability capacity in the first days, which indicate revealed that blending at high speeds followed by ultrasonication in an ultrasonic homogenizer for 40 minutes increases the stability of the mixes. The nano fluid fuel was gradually decreasing during the next following 8 days, but all of the blended fuel remains stable for percentage above 80 percent that UV-Vis 3 step method is trustable for investigating the stability of the nano enhanced fuel

    Self-supervised deep learning for highly efficient spatial immunophenotyping

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    Background: Efficient biomarker discovery and clinical translation depend on the fast and accurate analytical output from crucial technologies such as multiplex imaging. However, reliable cell classification often requires extensive annotations. Label-efficient strategies are urgently needed to reveal diverse cell distribution and spatial interactions in large-scale multiplex datasets. / Methods: This study proposed Self-supervised Learning for Antigen Detection (SANDI) for accurate cell phenotyping while mitigating the annotation burden. The model first learns intrinsic pairwise similarities in unlabelled cell images, followed by a classification step to map learnt features to cell labels using a small set of annotated references. We acquired four multiplex immunohistochemistry datasets and one imaging mass cytometry dataset, comprising 2825 to 15,258 single-cell images to train and test the model. / Findings: With 1% annotations (18–114 cells), SANDI achieved weighted F1-scores ranging from 0.82 to 0.98 across the five datasets, which was comparable to the fully supervised classifier trained on 1828–11,459 annotated cells (−0.002 to −0.053 of averaged weighted F1-score, Wilcoxon rank-sum test, P = 0.31). Leveraging the immune checkpoint markers stained in ovarian cancer slides, SANDI-based cell identification reveals spatial expulsion between PD1-expressing T helper cells and T regulatory cells, suggesting an interplay between PD1 expression and T regulatory cell-mediated immunosuppression. / Interpretation: By striking a fine balance between minimal expert guidance and the power of deep learning to learn similarity within abundant data, SANDI presents new opportunities for efficient, large-scale learning for histology multiplex imaging data. / Funding: This study was funded by the Royal Marsden/ ICR National Institute of Health Research Biomedical Research Centre

    Engine emissions analysis of emulsified fuel of different blend ratios

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    Diesel engines are widely used because of their fuel efficiency in producing a higher mechanical energy ratio compared to gasoline engines. The current study is an extension of these efforts where diesel and biodiesel blend are modified to emulsify and oxygenate through water and alcohol to reduce NOx emissions from the exhaust. Biodiesel on the other hand, has the advantage of being sulfur-free, which reduces the emission of smoke and particulate matters but unfortunately increases NOx emissions. Meanwhile, emulsion fuel is found to lower the temperature of the cylinder during combustion and thus, reduce the release of NOx gas. The oxygenated fuels are tested for their emission behaviors in a four-stroke, single cylinder, water cooled, and direct fuel injection engine evaluated at a speed of 1200 rpm until 2400 rpm with the engine load varied at 0%, 50% and 100%. The method of fuel oxygenation and their effect on the concentration of NOx are discussed. The results have demonstrated a significant reduction in the NOx emission with an increase in the fraction ratio of palm oil biodiesel. The competition to produce high-performance and environmentally friendly fuels has made emulsion fuel and biodiesel renewable fuels believed to be new alternative fuels that emit very little NOx emissions into the atmosphere

    A review of the performance and emissions of nano additives in diesel fueled compression ignition-engines

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    This paper reports the results of various researches on the engine performance and emission characteristics of Diesel engine using nano particles additives in diesel, biodiesel and water emulsified fuels. There are two methods of reducing the exhaust gas emission of the Diesel engine. First method is to reduce the emissions by using exhaust gas treatment devices like catalytic converter and diesel particulate filter. However, use of these devices affects the performance of Diesel engine. Second method to reduce emissions and improve performance of CI engine is the use of fuel additive. Main pollutants of Diesel engine are oxide of nitrogen (NOx) and particulate matter (PM). However, it is difficult to control NOx and PM simultaneously. Many researchers report that the best method to control the emissions and improve the engine performance is the use of nano particles additives and water emulsified fuels. This research paper also reports the biodiesel fuel as an alternative to diesel fuel by using various nano particle additives. Comparative studies of effects on various properties of diesel and biodiesel fuels without/with water contents and nano particles additives by previous researchers are done. Most of the researchers reported improved engine performance and reduction in emission characteristics with dosing of nano particles additives in diesel and biodiesel
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