75 research outputs found

    Penetration Forces for Subsurface Regolith Probes

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    Investigating planetary bodies using penetrometers can provide detailed information about its history and evolution. An estimation of subsurface density and porosity can be made from the shape of the penetration curve. Using penetrometers mounted on planetary platforms could be challenging due to the uncertainty of the subsurface composition and since the maximum allowed force for penetration is the weight of the lander or rover on the surface. Estimation of penetration forces can provide a reliable constraint on the maximum reachable depth without endangering the whole mission. Therefore, knowledge of the required penetration force to specific depths can be helpful in designing the length and shape of the probe. Test probes covering the anticipated diameter (2.5, 1.9, 1.2 and 0.9 cm diameter) and tip angle (30°, 60°, 90°and 120°) were inserted mechanically into regolith analogs. The results showed that tip angle does not have a major effect, while probe diameter and density of the regolith are the most important parameters. Increasing probe diameter from 0.9 to 1.9 cm (i.e. a factor of 2) leads to an increase in penetration force from 200 to 1000 N (i.e. a factor of 5) at 20 cm depth. An increase in bulk density from 1550 to 1700 kg/m3 leads to an increase in penetration force from 10 to 200 N at 20 cm depth. Square probes required less force than circular ones which can allow for easier design of lateral windows

    Subsurface Planetary Investigation Techniques and Their Role for Assessing Subsurface Planetary Composition

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    Subsurface planetary investigation techniques are of high interest and importance for the scientific community. Not only they can enhance our knowledge of the history of planetary formation but also can lead to information about its future. Whether the investigation is being conducted remotely using imagers, radars or physically using penetrometers or drills, a pre-existed knowledge of the mechanical and electrical properties of the subsurface regolith should be acquired for better data interpretation and analysis. Therefore, the main objective of this work is to investigate the mechanical and electrical properties of planetary analogs, understand their role for assessing the subsurface structure and identify their character for subsurface investigation techniques. Through-out this research, we investigated the mechanical and electrical properties of regolith analogs with emphasis on testing the feasibility of using penetrometer to explore the subsurface of planetary bodies and estimate their structure and layering. We found probe\u27s diameter and regolith density are the most dominant factors which affect penetration forces. We correlated the mechanical and electrical properties of regolith analogs to geomorphological shape formation. An increase in gully total length corresponds to an increase in dielectric constant, friction angle and formation bulk density which will enhance previous, current and future modelling, interpretation and analysis of optical imagery and radar data. We performed dielectric permittivity and hardness measurements for volcanic rocks in order to provide a cross relation between the dielectric constant of the investigated material and its hardness property. A linear increase in dielectric constant observed along with an increase in rock hardness. This will enhance characterization of the shallow subsurface when investigated using radar and drill/penetrometer

    Pulmonary Hypertension in Patients with Treated Pulmonary Tuberculosis: Analysis of 14 Consecutive Cases

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    Background Pulmonary tuberculosis (PTB) is an increasing global health problem that continues to cause significant morbidity and mortality. The impact of PTB has been measured in terms morbidity and mortality and little attention has been paid to continuing respiratory disability in those who were cured. Pulmonary hypertension (PHT) is a serious respiratory disability that results from structural lung damage and chronic hypoxia. This study was conducted to investigate the presence of PHT in a cohort of treated PTB patients who presented with shortness of breath. Methods This is a cross-sectional study that included 14 consecutive patients who were cured of PTB and presented with shortness of breath. Demographic and clinical data were recorded for all patients. PHT was diagnosed using Doppler echocardiography. Results Fourteen patients who were treated for PTB and were found to have PHT were studied. All patients were sputum smear negative at the time of the study. The mean age (SD) was 43.1 (13.6) and half of the patients were males. The mean number of years since PTB was diagnosed (SD) was 9.4 (10.9). All patients had abnormal chest x-rays. The commonest radiological abnormality was fibrocavitation which occurred in 50% of patients. Estimated pulmonary artery systolic pressure (PASP) of 51 to 80 mm/Hg was found in 9 patients (64.3%) whereas PASP of 40 to 50 mm/Hg was found in 4 patients (28.6%) and one patient had PASP more than 80 mm/Hg. Conclusions Different grades of PHT occurred in this cohort of treated PTB patients on average about 9 years after cure. The findings of this study support implementation of strategies for early detection and prevention of PTB. For those who were cured from PTB, longer periods of disability should be implemented in assessment of disease burden

    Clinical features and antinuclear antibodies profile among adults with systemic lupus erythematosus and lupus nephritis: a cross-sectional study

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    Introduction: Limited data is available regarding the clinical manifestations and pattern of Systemic Lupus Erythematosus (SLE) in Sudan. This study aimed to determine the clinical manifestations and Antinuclear Antibodies (ANA) profile among Sudanese adults with SLE and lupus nephritis (LN).Methods: A descriptive study was conducted in Omdurman Military Hospital, Sudan. It included all adults with SLE and on regular follow-up during the study period (December 2012 to May 2013). These were investigated regarding their demographic details, clinical features, and immunological profile (ANA, anti-double stranded DNA, and ANA profile 3 levels). Patients with LN had their pattern of renal involvement described; furthermore, associations between the various SLE reactive antibodies and the histological diagnosis of lupus were studied.Results: Sixty-two Sudanese adults with SLE were included, their mean age was 31 ± 10.9 year. Females made 93.5% of patients. A clear predominance of those of Arab ancestry was seen, with most patients being from the Ja'alin and Shaigiya ethnic groups accounting for 29% and 12.9%, respectively. Arthritis was the dominant clinical manifestation seen in 85.5%, whereas renal involvement was seen in 66.1% of patients. Lupus nephritis class III was the dominant histological lesion, seen in 39% of patients. On correlating the ANA profile to the histopathological diagnosis of LN, anti-Nucleosomes and anti-AMA-M2 autoantibodies were found to be significantly associated with LN class IV and class VI, respectively (P values < 0.05).Conclusion: Further epidemiological studies regarding SLE and its ANA profile remain essential as they might help predicting the clinical patterns of the disease and its prognosis.Keywords: SLE, lupus nephritis, ANA profile, Suda

    Composition of Mycoflora and Aflatoxins in Lupine Seeds from the Sudan

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    Thirteen seed samples of lupines (Lupinus termis Forrsk.) were evaluated for their phytosanitary status by incubation on potato-dextrose agar (PDA) and moist sterile filter papers (blotter method) at 28±2ºC. The seeds were also assayed for the presence of aflatoxins and toxigenic fungi. Forty-seven species and 10 varieties in 14 genera of fungi were recovered. Among these, 45 species and 10 varieties were new to lupine seeds, and 5 species and 2 varieties were new to the mycoflora of the Sudan. The genus Aspergillus (10 species, 8 varieties) was the most common, followed by Rhizopus (1 species), Fusarium (6 species) and Alternaria (5 species), while the remaining genera (Chaetomium, Cladosporium, Curvularia, Drechslera, Penicillium, Phoma, Emericella, Mucor, Sclerotium, Ulocladium) displayed lower levels of contamination. Of possible pathogens on lupine plants, Alternaria (5 species) (stem lesion) and F. oxysporum (root rot) were recovered from the seeds. Thin-layer chromatographic analysis of chloroform extracts of the 13 seed samples revealed that two samples contained very low concentrations of aflatoxins B1 and B2 (4.5-6.5 µg/kg)

    Machine Learning Methods for Better Water Quality Prediction

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    In any aquatic system analysis, the modelling water quality parameters are of considerable significance. The traditional modelling methodologies are dependent on datasets that involve large amount of unknown or unspecified input data and generally consist of time-consuming processes. The implementation of artificial intelligence (AI) leads to a flexible mathematical structure that has the capability to identify non-linear and complex relationships between input and output data. There has been a major degradation of the Johor River Basin because of several developmental and human activities. Therefore, setting up of a water quality prediction model for better water resource management is of critical importance and will serve as a powerful tool. The different modelling approaches that have been implemented include: Adaptive Neuro-Fuzzy Inference System (ANFIS), Radial Basis Function Neural Networks (RBF-ANN), and Multi-Layer Perceptron Neural Networks (MLP-ANN). However, data obtained from monitoring stations and experiments are possibly polluted by noise signals as a result of random and systematic errors. Due to the presence of noise in the data, it is relatively difficult to make an accurate prediction. Hence, a Neuro-Fuzzy Inference System (WDT-ANFIS) based augmented wavelet de-noising technique has been recommended that depends on historical data of the water quality parameter. In the domain of interests, the water quality parameters primarily include ammoniacal nitrogen (AN), suspended solid (SS) and pH. In order to evaluate the impacts on the model, three evaluation techniques or assessment processes have been used. The first assessment process is dependent on the partitioning of the neural network connection weights that ascertains the significance of every input parameter in the network. On the other hand, the second and third assessment processes ascertain the most effectual input that has the potential to construct the models using a single and a combination of parameters, respectively. During these processes, two scenarios were introduced: Scenario 1 and Scenario 2. Scenario 1 constructs a prediction model for water quality parameters at every station, while Scenario 2 develops a prediction model on the basis of the value of the same parameter at the previous station (upstream). Both the scenarios are based on the value of the twelve input parameters. The field data from 2009 to 2010 was used to validate WDT-ANFIS. The WDT-ANFIS model exhibited a significant improvement in predicting accuracy for all the water quality parameters and outperformed all the recommended models. Also, the performance of Scenario 2 was observed to be more adequate than Scenario 1, with substantial improvement in the range of 0.5% to 5% for all the water quality parameters at all stations. On validating the recommended model, it was found that the model satisfactorily predicted all the water quality parameters (R2 values equal or bigger than 0.9). © 201

    BIOLOGICAL AERATED FILTERS (BAFs) FOR CARBON AND NITROGEN REMOVAL: A REVIEW

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    Biological aerated filters (BAFs) are an emerging wastewater treatment technology designed for a wide range of municipal and industrial applications. This review paper presents and discusses of the influence C/N ratio, nitrification and denitrification principle, effect of pH, DO and alkalinity on the nitrification and denitrification systems, organic and hydraulic loading of BAF reactor, etc. Results from upflow and downflow biofilter pilot at different condition, with nitrification and denitrification are reviewed. Under the optimal conditions, significant amount of COD, ammonia-nitrogen and total nitrogen were removed. Removal rates based on reactor volume for different carbon-aceous COD and ammonia loading rate are reported. The BAF system for the nitrification and denitrification processes for carbon and nitrogen removal from the wastewater need to be evaluated and applied properly to protect of our environment and resources

    Utilization of information and communication technology among undergraduate nursing students in Tanta university, Egypt

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    The use of ICT to enhance learning and teaching has become increasingly important. Information and communication technology in education is a modern, efficient and cost effective process which has created a need to transform how students and teachers from higher institutions learn and teach respectively. This study was conducted to assess the pattern and utilization of Information and Communication Technology among undergraduate Nursing students in Tanta University, Egypt. A descriptive cross sectional design was used for the study where 504 fourth year students enrolled in the 2015/2016 session participated in the study. A validated structured questionnaire was used for data collection. The data collected were analyzed using Statistical Package for Social Science (SPSS) version 20. The results indicated that 80% of the surveyed students utilized ICT in performing their study assignments and research. Majority of the female students (79.0%) self reported themselves as good in computer skills while only one fifth (21.0%) of the male students rated themselves as good in computer skills. Students whose parents had secondary education and above had their total score in self-rating of computer operation skills as significantly higher than those whose parents had below secondary education. The study concluded that majority of the students had good ICT utilization with variation to residence and family income. It is therefore recommended that the university should ensure strict compliance with the rules of e-learning courses for the students and ensure proper application by each student

    Biochemical Characterization and Antimicrobial Activity Against Some Human or Phyto-Pathogens of New Diazonium Heterocyclic Metal Complexes

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    String of vanadium (IV), zirconium (IV), palladium (II), platinum (IV) and uranium (VI) chelates of 2-cyano-2-[(2- nitrophenyl)hydrazono]thioacetamide (Cnphta) were prepared and characterized by physicochemical, spectroscopic and thermal analyses. The formulae of the isolated solid complexes were assigned as [VO- (Cnphta)2(H2O)]SO4 ·5H2O (1), [ZrO(Cnphta)2(H2O)]Cl2 ·4H2O (2), [Pd(Cnphta)2]Cl2 (3), [Pt(Cnphta)2Cl2]Cl2 (4) and [UO2(Cnphta)2](NO3)2 ·5H2O (5). The infrared assignments clearly showed that Cnphta ligand coordinated as a bidentate feature through the hydrazono nitrogen and the thioacetamide nitrogen for V(IV), Zr(IV) and U(VI) but displayed different behavior for Pd(II) and Pt(IV). Results of the molar conductivities measurements showed that the metal complexes were electrolytes in contrast with Cnphta ligand. The interpretation, mathematical analysis and evaluation of kinetic parameters were also carried out. In addition, the studied ligand and its new chelates were tested for their antimicrobial activity against some human or phytopathogenic microorganisms. The new metal complexes explicated promising antibacterial activity against all tested bacteria especially Staphylococcus aureus and Bacillus subtilis. Regarding the antifungal activity, all metal complexes were able to inhibit the mycelium growth of both tested pathogenic fungi. In particular Zr(IV) and Pt(IV) complexes showed the highest significant fungicidal effect against A. fumigatus similar to positive contro

    Nationwide cross-sectional survey of schistosomiasis and soil-transmitted helminthiasis in Sudan: study protocol.

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    BACKGROUND: Schistosomiasis and soil-transmitted helminthiasis (STHs) are target neglected tropical diseases (NTDs) of preventive chemotherapy, but the control and elimination of these diseases have been impeded due to resource constraints. Few reports have described study protocol to draw on when conducting a nationwide survey. We present a detailed methodological description of the integrated mapping of schistosomiasis and STHs on the basis of our experiences, hoping that this protocol can be applied to future surveys in similar settings. In addition to determining the ecological zones requiring mass drug administration interventions, we aim to provide precise estimates of the prevalence of these diseases. METHODS: A school-based cross-sectional design will be applied for the nationwide survey across Sudan. The survey is designed to cover all districts in every state. We have divided each district into 3 different ecological zones depending on proximity to bodies of water. We will employ a probability-proportional-to-size sampling method for schools and systematic sampling for student selection to provide adequate data regarding the prevalence for schistosomiasis and STHs in Sudan at the state level. A total of 108,660 students will be selected from 1811 schools across Sudan. After the survey is completed, 391 ecological zones will be mapped out. To carry out the survey, 655 staff members were recruited. The feces and urine samples are microscopically examined by the Kato-Katz method and the sediment smears for helminth eggs respectively. For quality control, a minimum of 10% of the slides will be rechecked by the federal supervisors in each state and also 5% of the smears are validated again within one day by independent supervisors. DISCUSSION: This nationwide mapping is expected to generate important epidemiological information and indicators about schistosomiasis and STHs that will be useful for monitoring and evaluating the control program. The mapping data will also be used for overviewing the status and policy formulation and updates to the control strategies. This paper, which describes a feasible and practical study protocol, is to be shared with the global health community, especially those who are planning to perform nationwide mapping of NTDs by feces or urine sampling
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