Hydrogeophysical and Structural Investigations Using VES: A Case Study of Dosso Region in the Southwestern Part of the Meso-Cenozoic Iullemmeden Basin (Southwestern Niger)

A regional study connecting geolelectrical surveys with geology and hydrogeology was carried out in the western part of the Iullemmeden basin, precisely in the Dosso region in Niger. One hundred and four (104) vertical electrical sounds have been realized, among them nineteen representative were thus be used as parametric surveys. The local resistivity values of the geological formations of Quaternary range from 100 Ω⋅m to 1000 Ω⋅m (sands and lateritic sandstones). The Oligo-Miocene formation of the Continental terminal (Ct) shows resistivity values ranging from 1 to 5 Ω⋅m (brackish groundwaters) to 1500 Ω⋅m (clay sandstones) while the Upper Cretaceous formation of the Continental “hamadien” (Ch) indicates values ranging from 20 Ω⋅m (sandy clay) to 5000 Ω⋅m (clayey sandstones). The geological formations of Paleocene have values from 2 Ω⋅m (marls) to 60 Ω⋅m (calcareous marl), while the Precambrian basement exhibits values of granite around 300 Ω⋅m to 60,000 Ω⋅m. The update of the structural settings reveals many faults in the study area which explain both the shape of the basin and the geometry of the aquifers. Tectonics is also consistent with the hydraulic characteristics of aquifers. In addition, brackish groundwaters were identified as perched aquifer groundwaters in different depths in Dosso region. They probably come from the marine brines during the regression of the Paleocene Sea.

Alternative Phenotypic Profile for B-Cell Abnormality in a Case at Zinder National Hospital

Introduction: Since it is impossible to establish a diagnosis in the presence of hyperlymphocytosis not secondary to lymphocytic hyperactivation, we considered a B-lymphoid hematopathy with a non-specific phenotypic profile. We report one case of this. Observation: This is a forty-eight (48) year old patient with hyperlymphocytosis at 139,000 elements per cubic millimeter, heterogeneous splenomegaly at 25.6 cm in diameter on abdominal ultrasound without detectable deep or peripheral lymphadenopathy. Peripheral blood cytology shows lymphocyte cell proliferation suggestive of the circulating phase of chronic lymphoproliferative B syndrome. The expression profile of cell membrane markers did not allow for the definition of a specific phenotypic profile. Faced with this immunophenotyping result, we considered a B-lymphoid hemopathy with a non-specific phenotypic profile. After three courses, the MINICHOP treatment was used to achieve partial remission with wasting of more than 80% of the evaluable masses. Conclusion: Despite the contribution of immunophenotyping in the diagnosis of lymphoproliferative syndromes, it is possible to consider the diagnosis of a B-lymphoid hemopathy with a phenotypic non-specific profile of CD45+, monotypic kappa, CD19+, FMC7+, CD22+, CD5−, CD79b−, CD23−, CD43−, CD38−, CD200−.

Clinical and Bacteriological Profile of Infections in Sickle Cell Children in Two Referral Hospitals in Niamey, Niger

Introduction: Infections are significant causes of mortality in sickle cell children in resource-limited countries. This study aimed to determine the clinical profile and bacterial ecology of infections in children with sickle-cell disease in two referral hospitals in Niamey. Patients and methods: A retrospective descriptive study was conducted from January 2018 to July 2020 in two referral hospitals in Niamey. All children aged one (1) to 15 years with sickle cell disease admitted for suspected infection, including at least one bacterial culture, were studied. Bacteriological analysis was performed using the appropriate culture media, using BactAlert (Reference 4700003 BTA3D60 BioMérieux). Results: Over 36-months, 350 children with a mean age of 10.9 months were admitted. The sex ratio was 1.2. The SS electrophoretic profile was the most common (93.4%). Immunization status was up to date in 66% of patients. Fever was the common reason for consultation (55.1%). Infection was confirmed in 62 patients (17.7%). The primary diagnoses were bacterial gastroenteritis (24.2%) and urinary tract infection (19.4%). Blood cultures were isolated from Salmonella typhi (13.0%) and Escherichia coli (8.7%). Klebsiella spp (7.1%) and Escherichia coli (5.0%) were detected in cytobacteriological examination of urine. Salmonella typhi (23.5%) and Escherichia coli (5.9%) were isolated on coproculture. Conclusion: Bacterial ecology appears not different from that usually observed in sickle-cell children. Salmonella and Escherichia coli were predominant.

Sickle Cell Disease in the Zinder Region in 2023: Prevalence and Sociodemographic Factors

Introduction: In view of the number of sickle cell patients and due to a low production of descriptive studies, we decided to determine the prevalence of genes S and C of the disease in the Zinder region. The objective was to contribute to improving the management of sickle cell disease in Zinder. Methodology: This was a systematic screening by the “Sickle Scan” test of any blood donor admitted to the Zinder Regional Blood Transfusion Center during the 6-month study period, from January to June 2023. The Sickle Scan is a qualitative lateral flow chromatography immunoassay using whole blood samples that aid in the rapid diagnosis of sickle cell disease. Results: The study was carried out on 613 samples during the period concerned. The frequency of sickle cell genes was 26.9% (n = 165) in all samples collected, with 23.1% (n = 142) and 3.8% (n = 23) for the S gene and the C gene, respectively. The 18 - 30 age group was the most represented with 64.4% (n = 395) cases. The median age of blood donors was 26 years ± 10 years (min = 18 years/max = 60 years). The sex ratio was 2.5. Donors of Nigerien nationality accounted for 84.1% (n = 516). There is a predominance of blood donors with an average monthly income between 34,000 and 70,000 CFA francs in 44.3% (n = 272), lived in permanent housing with drinking water supply. Sickle cell trait (SMA) was found in 22.5% (n = 138). Conclusion: The analysis of these results highlights a high frequency of the S gene for sickle cell disease. The population with an average monthly income is the most affected, with a male predominance.

Sexual Assault and Its Psychopathological Repercussions in the Life of Female Students in Northeastern Benin (2023)

Objective: The aim of the present study was to investigate the psychic repercussions of sexual assault among female students in Parakou in 2023. Methods: Descriptive cross-sectional study conducted from December 2022 to July 2023 among all students at the University of Parakou. The sampling technique was stratified non-proportional at two levels. The dependent variable was self-reported sexual assault. The psychopathological repercussions linked to sexual assault and explored in these students were: post-traumatic stress disorder assessed with the Post Traumatic Stress Disorder Checklist-5 (PCL-5) scale;and current depression screened with the Patient Health Questionnaire-9 (PHQ-9) scale. Results: A total of 376 female students from the University of Parakou meeting the inclusion criteria were surveyed. The average age of the subjects surveyed was 20.56 ± 2.46 years, with extremes of 16 and 32 years. A predominance of subjects under 25 was observed. The prevalence of sexual assault among female students at the University of Parakou was 10.63%. The types of aggression suffered were mostly rape (18 people;45%) and sexual touching (16 people;40%), and the aggressors were mainly friends/boyfriends (13;32.5%), family members (12;30.0%) and people from the house/neighborhood (9;22.5%). Psychological repercussions included depression in 72.5% (29) of cases, with mild depression in 30% (12), moderate depression in 37.5% (15) and severe depression in 5% (2). Anxiety disorders were present in 27.50% (11) of victims. The risk factors associated with sexual assault in these students were gravidity (p = 0.014;OR = 15.32), unhappy life events (p = 0.01;OR = 17.24), and age of first sexual intercourse (p = 0.016;OR = 4.608). Conclusion: One in ten female students in Parakou has been sexually assaulted. Once again, preventive action through effective sex education is a means of fighting the problem that should be prioritized for every girl and boy from an early age. Psychological support by specialists should be offered to any victim discovered without delay. Communication on the subject should be multiplied in all family and academic educational environments, from the lowest to the highest levels.

Trends of Land Use and Land Cover Change in the Savannah Ecological of the Protected Area Reserve Partielle de Dosso, Niger

Information on the dynamics of savannah is important to a country's plan to overcome the problems of uncontrolled development and environmental hazards. Taking the reserve partielle de Dosso, Niger as the case study area, this paper analyzed the long-term land use land cover change from 2002 to 2022. Satellite images were processed by using Google Earth Engine (GEE). Therefore, four major land cover classes were identified based on spectral characteristics of Land sat, namely, built-up, vegetation, cropland, bare land and water. The result revealed that barren and built-up areas increased at the expense of vegetation and water. From the four major land use land cover the large area is covered by vegetation which comprises about 192963.5 hectares followed by cropland and water consisting of 32506.43 and 1596.4 hectares respectively. The built-up area gained substantial area (most) during the study period. The reduction in some of the land cover/uses underlines the dangerous trend of the pressure poised by population growth and the changing functionality. Land cover change is influenced by a variety of societal factors operating on several spatial and temporal levels. The area estimates and spatial distributions of the LULC classes produced from the current study will assist local authorities, managers, and other stakeholders in decision-making and planning regarding forest land cover and uses.

Hyperuricemia in Patients with Chronic Renal Failure in the General Hospital of National Reference of N’Djamena (Chad)

Introduction: Hyperuricemia is defined as a level of serum uric acid greater than or equal to 70 mg/l (420 μmol/l) in men and 60 mg/l (360 μmol/l) in women. Several studies have shown that it is a risk factor or a factor of progression of chronic kidney disease. Recent experimental and epidemiological data correlate the association of hyperuricemia with chronic kidney disease (CKD), arterial hypertension and cardiovascular diseases, thus raising the question of the usefulness of therapeutics in the prevention of renal diseases. The objective of this study is to seek a link between chronic kidney disease and hyperuricemia. Materials and Methods: This is a descriptive and analytical study conducted at hemodialysis unit and cardiology service of General Hospital of National reference of N’Djamena (Chad) from 1th January to 1th October 2013 (10 months). We included all chronic kidney disease patients hospitalized in hemodialysis unit and cardiology service who presented associated hyperuricemia. Results: There were 712 CKD patients who were hospitalized. Among them, there were 108 patients who were included in the study and who had hyperuricemia as a prevalence of 15.20%. The average age of patients was 35.5 years and the sex ratio was 3/1. The age group between 40 to 60 years represented 54.6%. There were 41.7% of traders. Hypertensive patients accounted for 49.1%;association of diabetes and hypertension was noted in 12.90%. Renal insufficiency was moderate in 43.5% of patients. Hyperuricemia was present in more than 90% of patients. Profession, age, hematuria, proteinuria and hypertension were statistically positively related to hyperuricemia. Treatment consisted of prescribing allopurinol in 84% of patients. In more than 11% of patients the progression was unfavorable. Conclusion: The implication of hyperuricemia in chronic kidney disease has been proved in several recent studies. However, randomized studies at very long scales have to be carried out to conclude from its real impact on the prevention and treatment of chronic kidney disease.

Bounds for Polynomial’s Roots from Fiedler and Sparse Companion Matrices for Submultiplicative Matrix Norms

We use submultiplicative companion matrix norms to provide new bounds for roots for a given polynomial P(X) over the field C[X]. From a n×n Fiedler companion matrix C, sparse companion matrices and triangular Hessenberg matrices are introduced. Then, we identify a special triangular Hessenberg matrix Lr, supposed to provide a good estimation of the roots. By application of Gershgorin’s theorems to this special matrix in case of submultiplicative matrix norms, some estimations of bounds for roots are made. The obtained bounds have been compared to known ones from the literature precisely Cauchy’s bounds, Montel’s bounds and Carmichel-Mason’s bounds. According to the starting formel of Lr, we see that the more we have coefficients closed to zero with a norm less than 1, the more the Sparse method is useful.

Review on Thermocline Storage Effectiveness for Concentrating Solar Power Plant

In this paper, a literature review on thermocline storage performance for Concentrating Solar Power (CSP) plant storage systems has been conducted. The efficiency of materials to store heat depends on the storage process like sensible heat storage, latent heat storage and thermochemical one and also on their properties. This study has been focused on sensible heat storage materials especially thermocline storage system (DMT) using eco-materials which has a high potentiality (35%) to reduce CSP cost. There is a possibility to use natural rocks, industry waste and to develop also materials for a thermocline storage within a bed called packed bed using one tank. The thermal storage materials should have some optimum parameters (particle diameter less than 2 cm and good thermo-physical properties) to achieve better thermal storage performance (thermal cycle efficiency, extraction factor). However, the size and the shape of natural rocks are uncontrollable (big diameter) and can drive to thermocline degradation, catastrophic thermal ratcheting and poor thermal stratification due to the variability of the storage system porosity and the stress on the storage tank wall. Also a better thermal storage efficiency is achievable at low velocity and with good thermo-physical properties of the HTF. The ratio H/D, the height, the porosity, the shape and the position of the tank should be optimized to increase the storage efficiency.

Sensitivity of Solar Photovoltaic Panel Efficiency to Weather and Dust over West Africa: Comparative Experimental Study between Niamey (Niger) and Abidjan (Côte d’Ivoire)

Energy demand is increasing while we are facing a depletion of fossils fuels, the main source of energy production in the world. These last years, photovoltaic (PV) system technologies are growing rapidly among alternative sources of energy to contribute to mitigation of climate change. However, PV system efficiency researches operating under West African weather conditions are nascent. The first objective of this study is to investigate the sensitivity of common monocrystalline PV efficiency to local meteorological parameters (temperature, humidity, solar radiation) in two contrasted cities over West Africa: Niamey (Niger) in a Sahelian arid area and Abidjan (Cote d’Ivoire) in atropical humid area. The second objective is to quantify the effect of dust accumulation on PV efficiency in Niamey (Niger). The preliminary results show that PV efficiency is more sensitive to high temperature change especially under Niamey climate conditions (warmer than Abidjan) where high ambient temperatures above 33°C lead to an important decrease of PV efficiency. Increase of relative humidity induces a decrease of PV efficiency in both areas (Niamey and Abidjan). A power loss up to 12.46% is observed in Niamey after 21 days of dust accumulation.

Female Genital Fistula Deemed Incurable in a National Obstetric Fistula Reference Center in Niger

Introduction Female genital fistula remains a global concern especially in incoming countries. The majority of cases resulted from obstructed delivery labor. The treatment is by surgery exceptional by probe for very small cases. But some ones remain incurable after several surgery theaters. The objective of this study is to establish the epidemiology anatomopathological types and prognosis of FGF considered being incurable in our center. Methods This is a retrospective and prospective descriptive study from January 2, 2017 to July 14, 2021 on incurable cases of female genital fistula recorded at the Centre National de Réparation de Fistule Obstétricale (CNRFO) of Niamey for complex cases of fgf. The epidemiology, the lesions of vagina, uretra, bladder, the treatment and prognosis have been studied. Results A total of 522 cases were operated within 5 cases given incurable (0.95%). The 5 cases were 37 - 49 years old, they had fistula at their first delivery, the mean age of the fistula was around 9 years. The anatomopathological founds were vaginal severe sclerosis, extensive supra-trigonal fistula, total ureteral destruction, and partial bladder destruction. All the 5 patients treated by surgery were declared incurable. Conclusion Female genital fistula is not life-threatening but a major definitive handicap for theses prim parous. The treatment fail is linked with local lesions, continuous urine and fecal incontinency, added by iterative surgery. They remain judged incurable whether a surgery was by skilled practitioner.

Study of Microbiological Quality along the Water Chain in Belbedji in the Republic of Niger

This work deals with the microbiological study along the water chain in Belbedji, a local government in the northwest of the Zinder region in the Republic of Niger. For this study, two (2) standpipes, thirty (30) families and ninety (90) samples were selected in order to follow the variation of water microbiological quality. For that the parameters studied are the total coliforms, the fecal coliforms and the E. coli. From these parameters we calculated the indication or the index of the microbiological quality (MQI) by the method of Bovesse and Depelchin, 1980. The variations of the fecal contamination at the level of the families in the different phases are represented on maps. At the water marker, 100% of families have good microbiological quality. After the transport of water, on 3.33% of the families the quality of the water deteriorated. After water storage, 16.66% of families had deteriorated water quality, with the passage of fecal contamination from zero to low on 13.33% of families, and fecal contamination from zero to moderate 3.33% of families.

Nucleation and Growth of Thallium on Thin Film Mercury Electrode: Voltammetric, Scanning Electron Microscopy, Chronoamperometric and Electrochemical Impedance Studies

Thallium is a heavy metal highly toxic to the biosphere. It can be determined by anodic stripping voltammetry after deposition on mercury film. The aim of this work is to study the conditions and mechanisms of deposition of Hg on glassy carbon electrode and Tl on Hg film by cyclic voltammetry, scanning electron microscopy, chronoamperometry and impedance techniques. The results showed a germination and growth of a 3D Hg phase on glassy carbon electrode. Similarly, the electrodeposition of Tl on Hg follows a 3D three-dimensional nucleation with diffusion controlled growth. The impedance measurements reveal an easier charge transfer on the Tl film.

Agro-Morphological Variability in Eight Bambara Groundnut (Vigna subterranea (L.) Verdc.) Morphotypes from Zinder (Niger)

Bambara groundnut (Vigna subterranea (L.) Verdc.) has economic importance for the producers and the traders as cash crop since it generates substantial income for households in Niger. The objective of this study was to assess eight (8) Bambara groundnut morphotype from Université André Salifou de Zinder in Niger Republic by their morphological and agronomic characters. The experiment was conducted in a randomized complete block design with three replications during the rainy season of 2020-2021. Data were collected on the Number of leaves, Plant height (cm), Growth habit (cm), Terminal leaflet length, Terminal leaflet width, Number of nodes/stem, Number of stems/plant, Number of pods/plant, Weight of 100 pods (g), Weight of 100 seeds (g), Length of seeds (mm), Width of seeds (mm), Weight of seeds/Plot (kg). There were significant differences for all characters, except Number of leaves, Terminal leaflet length, Terminal leaflet width, Length of seeds (mm) Weight of 100 pods (g), Weight of 100 seeds (g). The morphotypes UZ-VZ-04, UZ-VZ-03, UZ-VZ-06, UZ-VZ-02 and UZ-VZ-05 have demonstrated good performance for grain weight per plot and can be useful for a breeding program.

Profile of Patients with Acute Renal Injury in N’Djamena: About 36 Cases

Introduction: The incidence of acute renal injury (AKI) has increased in recent decades. Acute renal failure is defined by the abrupt arrest (within hours or days) of the kidney excretory function. Oliguria (urine output 24h) is presented in about half of the cases. The circumstances of the occurrence of AKI are multiple: surgical, traumatic, obstetric, medical, often obvious. Its prognosis depends on the speed of management and the associated organ failure. The objective of this study is to describe the profile of patients in emergency hemodialysis at the Nephrology Unit of the National Reference General Hospital (HGRN) in N’Djamena, Chad. Methods: This was a multicenter, descriptive study in patients with acute renal failure place over a period of 12 months in the emergency departments of the 2 hospitals in N’Djamena. Defined as carriers of an AKI (RIFLE criteria), patients with: 1) Oliguria: urinary output 400 ml/24h (<0.5 ml/kg/h in children) or anuria: urinary output 300 ml/24h;2) Associated with an increase in serum creatinine: serum creatinine × 3 or serum creatinine> 350 μmol/l or decrease of GFR by 75%. Results: Of the 311 patients admitted, 36 cases met the inclusion criteria, a frequency of 11.57%. The mean age was 34.46 years with extremes ranging from 7 to 80 years. The female sex predominated with 52.80% as sex ratio of 0.91. Isolated hypertension was noted with 38.88%. Dyspnea accounted for 41.66% of patients admitted to emergency departments. In our series, 50% of our patients had hyperthermia at admission. Oliguria was observed in 41.70% of the cases. Edema accounted for 33.33% of cases. The AKI with the “failure” criterion was 58.34% (21/36), with the criterion “injury” 25% (9 cases) and the criterion “risk” 16.66 (6 cases). AKI were organic in 83.34% (30/36). It was noted that 14 patients, 38.8% had an infectious syndrome. There were 6 patients who had (16.66%) an obstructive AKI, 5 patients (13.88%) had eclampsia, 4 patients (11.12%) had hepatocellular insufficiency, 3 patients (8.34% Cardiac, 2 patients (5.56%) extracellular dehydration and 2 patients (5.56%) whose cause is indeterminate. It was noted that 10 patients, as 27.7%, had fully recovered their renal function after vascular filling and etiological treatment. Four (4) patients with obstructive obstruction were referred to the urology department. There were 22 patients who had benefited from the hemodialysis. 6 patients recovered completely their renal function. We had recorded a number of deaths in our study which was 44.44% (16/36). Septic shock was the most frequent cause of death in 50% of cases. Conclusion: The incidence of AKI in our study was 11.57%. It affects a young population and despite the therapeutic progress, the mortality remains high. The causes are multiple, entangled, dominated by infectious syndrome and hypovolemia. Prevention seems to be the best therapeutic option to avoid the installation or worsening of an AKI.

Prevalence of Extended-Spectrum Beta-Lactamase-Producing Strains Isolated at Zinder National Hospital (ZNH) in 2021 and Their Antibiotic Susceptibility Profile

Purpose: Bacterial resistance to antibiotics has become a global public health problem. Enterobacteriaceae ESBL is among the most incriminated in this emergence which reduces the therapeutic possibilities. Thus, the objective of this study is to determine the prevalence of the extended-spectrum beta- lactamase (ESBL) producing Enterobacteriaceae at ZNH and their antibiotic susceptibility profile. Materials and Methods: This is a prospective study carried out over 5 months in all hospitalized and non-hospitalized patients in whom a culture was taken for the diagnosis of an infection. The search for ESBL is done by the double disc diffusion method. Results: In total, 21 out of 45 of our strains are ESBL-producing, i.e. a frequency of 46.7%. The mean age is 41.62 (±22.90) with extremes of 2.6 - 78 years. The distribution of ESBL producing species showed a predominance of E. coli with 66.7% followed by K. pneumoniae and K. oxytoca each 9.5%. All ESBL strains were resistant to Amoxicillin, Cefalotin, Pipiracillin, Piperacillin + tazobactam, Ticarcillin, Ticarcillin + clavulanic acid. Resistance to C3G and Aztreonam was each 95.5%, to Amoxicillin/clavulanic acid 9.1%. All strains were sensitive to imipenem. E. coli strains showed resistance: 85.7% to ciprofloxacin, 50% to Amikacin, 57.1% to Gentamicin. For K. pneumoniae, it is 66.7% for Gentamicin and Ciprofloxacin. Conclusion: Our study reports a high prevalence of ESBL at the HNZ. This must be taken into account in order to monitor this phenomenon which constitutes a public health problem. The study also reports sensitivity to Amoxicillin/clavulanic acid and Aminoside which can be an alternative.

Superior Mesenteric Artery Syndrome: First Chadian Observation

Introduction: The extrinsic compression of the third portion of the duodenum between the superior mesenteric artery and the aorta defines superior mesenteric artery syndrome. It determines an acute or chronic high intestinal obstruction pattern. We report the first observed case in Chad. Observation: HH was a 19 year-old woman with abdominal pain and intermittent postprandial vomiting since she was 5 years old. During last 11 months, post-prandial vomiting was more frequent, and non resolved after medical treatment. Unquantified weight loss was reported. Body mass index at hospitalization was 9.8. An injected abdominal scan demonstrated significant gastroduodenal distension, upstream of a stenosis of the third duodenal portion. Aorto-mesenteric space and angle were reduced. At laparotomy internal derivation by duodenojejunostomy was done. Postoperative situation was uneventful. Conclusion: Superior mesenteric artery syndrome determines an acute or chronic intestinal obstruction. Injected abdominal scan is fundamental for diagnosis. The treatment is firstly conservative but the need of surgery is common.

Entropy Formulation for Triply Nonlinear Degenerate Elliptic-Parabolic-Hyperbolic Equation with Zero-Flux Boundary Condition

In this note, we investigated existence and uniqueness of entropy solution for triply nonlinear degenerate parabolic problem with zero-flux boundary condition. Accordingly to the case of doubly nonlinear degenerate parabolic hyperbolic equation, we propose a generalization of entropy formulation and prove existence and uniqueness result without any structure condition.

Development of Sensible Heat Storage Materials Using Sand, Clay and Coal Bottom Ash

In this paper, the mechanical and thermal properties of a sand-clay ceramic with additives coal bottom ash (CBA) waste from incinerator coal power plant are investigated to develop an alternative material for thermal energy storage (TES). Ceramic balls are developed at 1000&deg;C and 1060&deg;C using sintering or firing method. The obtained ceramics were compressed with a compression machine and thermally analyse using Decagon devise KD2 Pro thermal analyser. A muffle furnace was also used for thermal cycling at 610&deg;C. It was found that the CBA increased the porosity, which resulted in the increase of the axial tensile strength reaching 3.5 MPa for sand-clay and ash ceramic. The ceramic balls with the required tensile strength for TES were selected. Their volumetric heat capacity, and thermal conductivity range respectively from 2.4075 MJ&middot;m-3&middot;&deg;C-1 to 3.426 MJ&middot;m-3&middot;&deg;C-1 and their thermal conductivity from 0.331 Wm-1&middot;K-1, to 1.014 Wm-1&middot;K-1 depending on sand origin, size and firing temperature. The selected formulas have good thermal stability because the most fragile specimens after 60 thermal cycles did not present any cracks. These properties allow envisioning the use of the ceramic balls developed as filler material for thermocline thermal energy storage (structured beds) in Concentrating Solar Power plants. And for other applications like solar cooker and solar dryer.

Electrical Energy Quality Analysis in Hospital Centres

Today, energy is a vital component in the functioning of a hospital. Hospital technical facilities have several types of technologies, these include appliances for use;examination apparatus. So, for Quality Health Care in a hospital, there is a need to ensure the proper functioning of hospital equipment. In addition to the required maintenance as specified by the device manufacturer, the quality of the electrical energy across the device must be ensured. This article is an analysis of the quality of electric energy at the substation of National Hospital of Niamey. Thereby, the data collection, followed by the data processing and analysis revealed the parameters characterizing the quality of electrical energy across the substation. Our studies have shown that the substation is underutilized as the maximum inrush current is less than half the available current. The current was consumed by the three phases has resulted in a strong current unbalance (230 A). However, the current unbalance and the voltage amplitude, are admissible accordingly base on EN50160 standard. Furthermore, the harmonics voltages present in this medium are in the accepted range (1.8%) according to IEEE 519 standard. However, the fundamental frequency does not meet the standard, but the difference obtained has no adverse effect.