Combined Effect Of NozzleDispersion Device On Spray Pattern Uniformity For Low Pressure Sprinklers

An impact sprinkler with a newly designed nozzle-dispersion device and R33 sprinkler were introduced in this study. Comparative experiments and analyses on uniformity patterns of impinging water jet from both sprinklers were investigated by using high-speed photographic technique to visualize the spray. A mathematical model of the spray was developed and applied in MatLab to determine the spray angles at different axial distances. Results showed that the impact sprinkler with the nozzledispersion device combination gave the largest spray range of 12.6% larger than the R33 sprinkler. Combined effect of the nozzle-dispersion device for the impact sprinkler had a strong effect on the spray angle which increased with increasing pressure. Spray characteristics for the impact sprinkler were similar to those produced by the R33 sprinkler. The number of droplets increased with increasing spray angle due to early breakup of the jet, which is beneficial for greater water dispersion and uniformity. It was found that a low working pressure of 150 kPa leads to lower degree of nonuniformities for the sprinklers, and the variation coefficient were less than 10%. Obtained mathematical models of the changes in the variation coefficient was dependent upon working pressure and can be a good basis for easy management of the parameters necessary for the uniform spray distribution. Hence, the impact sprinkler with the nozzle-dispersion device can offer superior advantage of a larger spray range for better overlap and disperse more droplets for better Uniformity under low pressure conditions

Using the Logistic Function to Illustrate Periodic Orbits as Recurrent Formation

Recurrence as behaviour in the dynamical system is also a state which happens as a result of an outcome of a point which does return to its initial state. But in dynamical system the most simple and easy way to study regime in one dimension is the logistic function. In this study we seek to understudy the recurrence as a full strong state from the nature or behaviour of the logistic function, where the periodic orbits as behaviour the logistic function is considered. A point can only be termed as recurrent if it is in its own future state. A periodic orbit returns infinitely often to each point on the orbit. And so it is clear that an orbit is recurrent when it returns repeatedly to each neighbourhood of its initial position. Recurrence as in dynamical system is a result of periodic formation which is a movement that returns back to the original state or position at a constant rate. A systematic example for each periodic point from the logistic function relative to a control parameter is discussed. Different iterations tables, diagrams (graphs) for against , tables of stability of periodic nature which shows relative range of the control parameter and are discussed. Through graphical illustrations and algebraic approach, the study showed that in the formation of recurrence through logistic function, the parameter played a major role and not all the periodic points (orbits) lead to recurrent formation. The study also showed that unstable behaviour of the logistic function when, ends the periodic behaviour, hence the absence of recurrence. And the absence of recurrent and the unstable nature of system bring about chaos

On the Regularization-Homotopy Analysis Method for Linear and Nonlinear Fredholm Integral Equations of the First Kind

Fredholm integral equations of the first kind are considered by applying regularization method and the homotopy analysis method. This kind of integral equations are considered as an ill-posed problem and for this reason needs an effective method in solving them. This method first transforms a given Fredholm integral equation of the first kind to the second kind by the regularization method and then solves the transformed equation using homotopy analysis method. Approximation of the solution will be of much concern since it is not always the case to get the solution to converge and the existence of the solution is not always guaranteed as this kind of Fredholm integral equation is not well-posed

Caractérisation Physico-Chimique Et Minéralogique Des Argiles De La Carrière De Mirriah, Région De Zinder, Utilisées Dans La Poterie

In order to contribute to the valuation of clay materials from the Zinder Region, the clays taken from the quarry and used for the pottery of Mirriah have been characterized from a physico-chemical and mineralogical point of view. So the five samples were taken and the composite sample representative of the quarry were subjected to chemical and mineralogical analyzes.The chemical analysis showed that the six samples all consisted of more than 60% aluminosilicates with a high silica/alumina ratio estimated at 2.5 on average. This report shows that the samples of this study are rich in clay minerals; this is in agreement with the estimate of the fine or clay fraction which is 39.5% of the initial mass of the raw sample. This chemical analysis also made it European Scientific Journal, ESJ ISSN: 1857-7881 (Print) e - ISSN 1857-7431 January 2021 edition Vol.17, No.3 www.eujournal.org 122 possible to highlight, at the level of these Mirriah clays, a significant iron oxide content of 32%, which gives them a brick red color. The main mineralogical phases detected by X-ray diffraction in the raw sample and its fine fraction are kaolinite, a mica structure close to illite and quartz, all weathering products of granite. This characterization indicates that the clays mined at the Mirriah quarry are very favorable materials for formulations of pottery products. Dans le but de contribuer à la valorisation des matériaux argileux de la Région de Zinder, les argiles prélevées à la carrière et utilisées pour la poterie de Mirriah ont été caractérisées du point de vue physico-chimique et minéralogique. Ainsi les cinq échantillons ont été prélevés et l’échantillon composite représentatif de la carrière, ont été soumis à des analyses chimiques et minéralogiques. Il ressort de l’analyse chimique que les six échantillons sont tous constitués à plus de 60 % d’aluminosilicates avec un rapport silice/alumine élevé estimé à 2,5 en moyenne. Ce rapport montre que les échantillons de cette étude sont riches en minéraux argileux ceci est en accord avec l’estimation de la fraction fine ou argileuse qui est de 39,5 % de la masse initiale de l’échantillon brut. Cette analyse chimique a aussi permis de mettre European Scientific Journal, ESJ ISSN: 1857-7881 (Print) e - ISSN 1857-7431 January 2021 edition Vol.17, No.3 www.eujournal.org 121 en évidence, au niveau de ces argiles de Mirriah, une teneur importante en oxyde de fer de 32% ceci leur induit une couleur rouge brique. Les phases minéralogiques principales détectées par diffraction des rayons X dans l’échantillon brut et sa fraction fine sont de la kaolinite, une structure de mica proche de l’illite et du quartz, tous des produits d’altération du granite. Cette caractérisation indique que les argiles exploitées à la carrière de Mirriah sont des matériaux très favorables aux formulations des produits de poterie

Determinants of Stunting and Severe Stunting Among Under-Fives in Tanzania: Evidence from the 2010 Cross-Sectional Household Survey.

Stunting is one of the main public health problems in Tanzania. It is caused mainly by malnutrition among children aged less than 5 years. Identifying the determinants of stunting and severe stunting among such children would help public health planners to reshape and redesign new interventions to reduce this health hazard. This study aimed to identify factors associated with stunting and severe stunting among children aged less than five years in Tanzania. The sample is made up of 7324 children aged 0-59 months, from the Tanzania Demographic and Health Surveys 2010. Analysis in this study was restricted to children who lived with the respondent (women aged 15-49 years). Stunting and severe stunting were examined against a set of individual-, household- and community-level factors using simple and multiple logistic regression analyses. The prevalence of stunting and severe stunting were 35.5 % [95 % Confidence interval (CI): 33.3-37.7] and 14.4 % (95 % CI: 12.9-16.1) for children aged 0-23 months and 41.6 % (95 % CI: 39.8-43.3) and 16.1 % (95 % CI: 14.8-17.5) for children aged 0-59 months, respectively. Multivariable analyses showed that the most consistent significant risk factors for stunted and severely-stunted children aged 0-23 and 0-59 months were: mothers with no schooling, male children, babies perceived to be of small or average size at birth by their mothers and unsafe sources of drinking water [adjusted odds ratio (AOR) for stunted children aged 0-23 months = 1.37; 95 % CI: (1.07, 1.75)]; [AOR for severely stunted children aged 0-23 months = 1.50; 95 % CI: (1.05, 2.14)], [AOR for stunted children aged 0-59 months = 1.42; 95 % CI: (1.13, 1.79)] and [AOR for severely stunted children aged 0-59 months = 1.26; 95 % CI: (1.09, 1.46)]. Community-based interventions are needed to reduce the occurrence of stunting and severe stunting in Tanzania. These interventions should target mothers with low levels of education, male children, small- or average-size babies and households with unsafe drinking water

Spatial dynamic of mobile dunes, soil crusting and Yobe’s bank retreat in the Niger’s Lake Chad basin part: Cases of Issari and Bagara

The process of desertification is accelerated in the northern part of Lake Chad basin since the early 1970. Those processes linked to the recurrent drought and a heavy human pressure induced a great environmental damages. So this study based on diachronic cartography (1957, 1975 and 2007) aimed to describe and quantify the degradation dynamics in the contrasting Niger’s Lake Chad basin part. Thus significant environmental changes have been observed in this area from 1957 to 2007. Indeed in the Manga, the natural commodities and fields were threatened by mobile dunes making blocking with sand: the mobile dunes spread from ~200 ha in 1975 to ~900 ha in 2007 while they had not watched in 1957. In the fluvio-deltaic area of Kadzell, the soil crusting and the Yobe River retreat remain the major damages. The crusting area has been multiplied by more than two while the lateral migration of the Yobe bank reached near of 3 m.yr-1. This study highlights the key role of man in the process of degradation related to climate parametersKey words: Lake Chad, degradation dynamics, soil crusting, dunes, human activities

Pharyngeal carriage of Neisseria species in the African meningitis belt.

OBJECTIVES: Neisseria meningitidis, together with the non-pathogenic Neisseria species (NPNs), are members of the complex microbiota of the human pharynx. This paper investigates the influence of NPNs on the epidemiology of meningococcal infection. METHODS: Neisseria isolates were collected during 18 surveys conducted in six countries in the African meningitis belt between 2010 and 2012 and characterized at the rplF locus to determine species and at the variable region of the fetA antigen gene. Prevalence and risk factors for carriage were analyzed. RESULTS: A total of 4694 isolates of Neisseria were obtained from 46,034 pharyngeal swabs, a carriage prevalence of 10.2% (95% CI, 9.8-10.5). Five Neisseria species were identified, the most prevalent NPN being Neisseria lactamica. Six hundred and thirty-six combinations of rplF/fetA_VR alleles were identified, each defined as a Neisseria strain type. There was an inverse relationship between carriage of N. meningitidis and of NPNs by age group, gender and season, whereas carriage of both N. meningitidis and NPNs was negatively associated with a recent history of meningococcal vaccination. CONCLUSION: Variations in the prevalence of NPNs by time, place and genetic type may contribute to the particular epidemiology of meningococcal disease in the African meningitis belt

Pharyngeal carriage of Neisseria species in the African meningitis belt.

OBJECTIVES: Neisseria meningitidis, together with the non-pathogenic Neisseria species (NPNs), are members of the complex microbiota of the human pharynx. This paper investigates the influence of NPNs on the epidemiology of meningococcal infection. METHODS: Neisseria isolates were collected during 18 surveys conducted in six countries in the African meningitis belt between 2010 and 2012 and characterized at the rplF locus to determine species and at the variable region of the fetA antigen gene. Prevalence and risk factors for carriage were analyzed. RESULTS: A total of 4694 isolates of Neisseria were obtained from 46,034 pharyngeal swabs, a carriage prevalence of 10.2% (95% CI, 9.8-10.5). Five Neisseria species were identified, the most prevalent NPN being Neisseria lactamica. Six hundred and thirty-six combinations of rplF/fetA_VR alleles were identified, each defined as a Neisseria strain type. There was an inverse relationship between carriage of N. meningitidis and of NPNs by age group, gender and season, whereas carriage of both N. meningitidis and NPNs was negatively associated with a recent history of meningococcal vaccination. CONCLUSION: Variations in the prevalence of NPNs by time, place and genetic type may contribute to the particular epidemiology of meningococcal disease in the African meningitis belt.MenAfriCar was funded by the Wellcome Trust (086546/Z/08/Z) and the Bill and Melinda Gates Foundation (51251). Kanny Diallo holds a Wellcome Trust Training Fellowship in Public Health and Tropical Medicine.This is the final version of the article. It first appeared from Elsevier via https://doi.org/10.1016/j.jinf.2016.03.01

Host candidate gene polymorphisms and clearance of drug-resistant Plasmodium falciparum parasites

Resistance to anti-malarial drugs is a widespread problem for control programmes for this devastating disease. Molecular tests are available for many anti-malarial drugs and are useful tools for the surveillance of drug resistance. However, the correlation of treatment outcome and molecular tests with particular parasite markers is not perfect, due in part to individuals who are able to clear genotypically drug-resistant parasites. This study aimed to identify molecular markers in the human genome that correlate with the clearance of malaria parasites after drug treatment, despite the drug resistance profile of the protozoan as predicted by molecular approaches

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries