The chemical composition of the volatile components of the dried roots of Scorzonera undulata ssp deliciosa collected from Algeria was determined by GC and GC/MS. The obtained results showed that the extracted oil con...The chemical composition of the volatile components of the dried roots of Scorzonera undulata ssp deliciosa collected from Algeria was determined by GC and GC/MS. The obtained results showed that the extracted oil contained nine fatty acids. The major compounds were hexadecanoic acid (42.2%), n-tetradecanoic acid (16.1%), 9-octadecenoic acid (7.7%) and 9-hexadecenoic acid (4.5%).展开更多
The one dimensional Schrodinger equation associated with a time-dependent Morse potentials is studied. We use the invariant operator method （Lewis and Riesenfeld） to obtain approximate solution of the Schrodinger eq...The one dimensional Schrodinger equation associated with a time-dependent Morse potentials is studied. We use the invariant operator method （Lewis and Riesenfeld） to obtain approximate solution of the Schrodinger equation in terms of solution of second order ordinary differential equation describes the amplitude of the Morse potentials.展开更多
In this paper we show that, under some conditions, if M is a manifold with Bakry-émery Ricci curvature bounded below and with bounded potential function then M is compact. We also establish a volume comparison th...In this paper we show that, under some conditions, if M is a manifold with Bakry-émery Ricci curvature bounded below and with bounded potential function then M is compact. We also establish a volume comparison theorem for manifolds with nonnegative Bakry-émery Ricci curvature which allows us to prove a topolological rigidity theorem for such manifolds.展开更多
The original online version of this article (Issa Allassane Kaboye, Bazanfaré Mahaman (2016) Manifolds with Bakry-Emery Ricci Curvature bounded below 6, 754-764. http://dx.doi.org/10.4236/apm.2016.611061 unfortun...The original online version of this article (Issa Allassane Kaboye, Bazanfaré Mahaman (2016) Manifolds with Bakry-Emery Ricci Curvature bounded below 6, 754-764. http://dx.doi.org/10.4236/apm.2016.611061 unfortunately contains a mistake. The author wishes to correct the errors.展开更多
Mathematical modeling plays a crucial role in understanding the dynamics of malaria transmission and can provide valuable insights for designing effective control strategies. Malaria indeed faces significant challenge...Mathematical modeling plays a crucial role in understanding the dynamics of malaria transmission and can provide valuable insights for designing effective control strategies. Malaria indeed faces significant challenges due to a changing climate, particularly in regions where the disease is endemic. This disease is significantly impacted by changes in climate, especially rising temperatures and fluctuating rainfall patterns. This study explores the influence of temperature and rainfall abundance on malaria transmission dynamics within the context of Burundi. We have constructed a deterministic model that integrates these climatic parameters into the dynamics of the human host-mosquito vector system. The model’s steady states and basic reproduction number, calculated using the next-generation method, reveal important insights. Numerical simulations demonstrate that both temperature and rainfall significantly influence mosquito population dynamics, leading to distinct effects on malaria transmission. Specifically, we observe that temperatures between 20˚C and 32˚C, along with rainfall ranging from 10 to 30 mm per month, create optimal conditions for mosquito development, thus driving malaria transmission in Burundi. Furthermore, our findings indicate a delayed relationship between rainfall and malaria cases. When rainfall peaks in a given month, malaria does not peak immediately but instead shows a lagged response. Similarly, when rainfall decreases, malaria incidence drops after a certain time lag. This same lagged effect is observed when comparing temperature with confirmed malaria cases in Burundi. These findings highlight the urgent need to consider climate factors in malaria control strategies.展开更多
Spinel-bearing lherzolite xenoliths from the Hossere Garba (1272 m.a.s.l) volcano on the Adamawa Plateau, is located in Likok village, at about 35 km to WSW of Ngaoundere. These xenoliths (~11 cm size) have been sampl...Spinel-bearing lherzolite xenoliths from the Hossere Garba (1272 m.a.s.l) volcano on the Adamawa Plateau, is located in Likok village, at about 35 km to WSW of Ngaoundere. These xenoliths (~11 cm size) have been sampled into the host basaltic lava flows from the NE flank of the Hossere Garba volcano. These xenoliths characterized by porphyroclastic texture consisted of olivine (~55 vol.%), orthopyroxene (~19 vol.%) and clinopyroxene (~21 vol.%) crystals. Spinel crystals (~5 vol.%) are red brown and interstitial between the crystals of olivine and pyroxenes. CaO contents are low (<0.08 wt%) in olivine and similar to those estimated (CaO: 0.05 - 0.1 wt%) for the mantle origin. The values of AlVI/AlIV ratio range between 1.1 and 1.3 for the Cr-diopside crystals from Hossere Garba xenoliths. The constant value of the volumes V(Cell) and V(M1) for clinopyroxene compositions, indicates the similar pressures. Hossere Garba represents a residual sequence issued from partial melting of a mantle source. Similar compositions have been recorded in minerals of ultramafic xenoliths from other ultramafic xenoliths domains of the Cameroon Line and the Adamawa Plateau.展开更多
We report the electrosynthesis of a novel semiconductor polymer based on alkyl vinylthiophene derivative in the presence of an ionic liquid (IL). The polymerization was performed under galvanostatic conditions and the...We report the electrosynthesis of a novel semiconductor polymer based on alkyl vinylthiophene derivative in the presence of an ionic liquid (IL). The polymerization was performed under galvanostatic conditions and the polymer was studied as potential donor component of a multilayer heterojunction organic solar cell (OSC). The monomer used was (E)-1,2-di-(3-octyl-2-thienyl) vinylene (OTV) and the IL used for the electropolymerization was 1-octyl-3-methylimidazole hexafluorophosphate C8mimPF6. Optical properties, stability and morphology of the polymer were analyzed using FT-IR, UV-vis, Raman and XPS spectroscopy. Voltammetry analysis and scanning electron microscopy (SEM-EDX) were also performed on the polymer. The OSC assembled with the polymer of OTV was used as electro donor and C60 as acceptor. Molybdenum trioxide (MoO3) and bathocuproine (BCP) were used as buffer layer between anode and cathode respectively. I-V curves, in the dark and under AM 1.5 solar simulator were performed to measure its efficiency.展开更多
Goal: The present study aimed to determine the profile of seric calcium and magnesium in pre-eclamptic and eclamptic pregnant women of Kinshasa province in the Democratic Republic of Congo where preeclampsia is charac...Goal: The present study aimed to determine the profile of seric calcium and magnesium in pre-eclamptic and eclamptic pregnant women of Kinshasa province in the Democratic Republic of Congo where preeclampsia is characterized not only by a high incidence, but also by a seasonal variation probably related to nutritional intake. Study Design: This is a case-control study that took place during the period from September 2014 to March 2015 in four quaternary and tertiary maternity hospitals in Kinshasa. A total of 113 healthy pregnant women (controls) and 112 pre-eclamptic and eclamptic pregnant women (cases) were included in this study. Seric calcium and magnesium were measured in all these gravidas by the principle of spectrophotometry with a HUMALYSER Primus semi-automaton. Results: The mean age of those gravidas was 26.8 ± 6.3 years (26.7 vs 26.9, p = 0.11). The majority of these gravidas were primiparous. The mean gestational age in both groups was 31.35 ± 0.9 weeks (32.1 vs 30.6, p = 0.21). The average seric calcium value was 4.47 ± 0.23 mEq /L in healthy pregnant women compared to 3.80 ± 0.71 mEq/l in pre-eclamptics (P 0.001). The mean of seric magnesium was 1.56 ± 0.15 mg/dL in healthy pregnant women compared to 1.20 ± 0.41 mg/dL in pre eclamptics (P 0.001). Seric calcium and magnesium values were low in the pre-eclamptic group and lower in the eclamptic group (P 0.001). Conclusion: This study establishes a relationship between the low concentration of seric calcium and magnesium with pre-eclampsia and eclampsia, which could be one of the determinants of the high prevalence and seasonality of the disease in Kinshasa.展开更多
<strong>Background: </strong>Parasitic diseases are threat to the development of Ivorian Pig industry. Zoonotic diseases such as Echinococcosis have a significant impact on animal health and production. Li...<strong>Background: </strong>Parasitic diseases are threat to the development of Ivorian Pig industry. Zoonotic diseases such as Echinococcosis have a significant impact on animal health and production. Little is known about Echinococcosis in C<span style="white-space:nowrap;">ô </span>te d’Ivoire. <strong>Aim:</strong> For these reasons, a cross section study was conducted at SIVAC in Yopougon, on pigs (<em>Sus scrofa domesticus</em>), in order to determine the prevalence and associated risk factors of Echinococcosis. <strong>Method:</strong> Paraclinical examinations of pig organs (kidneys, lungs, and liver) were conducted from 5<sup>th</sup> September to 30<sup>th</sup> December 2019 in order to report infection with this parasite. <strong>Results:</strong> Out of the 2425 slaughtered pigs, 63 of them were Echi-nococcosis positive, resulting in overall infection prevalence of 2.6% (95% CI: 1.9% - 3.22%). The kidneys (2.35%) were most infected, followed by lungs (0.21%), and liver (0.04%). <strong>Recommendations: </strong>A more in-depth study on the molecular epidemiology of Echinococcosis in the different regions of C<span style="white-space:nowrap;">ô </span>te d’Ivoire is underway. Also, capacity building of community livestock actors (Veterinarians, health inspectors, breeders and butchers) and sensitization of the population on this disease is necessary in order to improve its diagnosis at the abattoir level and to set up strategies to combat it.展开更多
Water is an essential element for all forms of life. The quantity and quality of water are a problem in places. In Kouba Adougoul and its surroundings in south guera, water-related health problems are reported. That i...Water is an essential element for all forms of life. The quantity and quality of water are a problem in places. In Kouba Adougoul and its surroundings in south guera, water-related health problems are reported. That is why this study focuses on the quality of water in the basement areas, of Kouba Adougoul. Our objective is to contribute to a better understanding of water of human consumption in these areas for this, we carried out a physicochemical and bacteriological control on a number water point. Ten water points were collected during May 2022 for analysis. To achieve this objective, we made the in-situ analysis of physical parameters such as pH, electrical conductivity, and temperature. These measurements were made using the multi-parameter kit. The result shows that, the water temperatures vary from 24.4˚C to 27.4˚C proving that the waters are from deep depths. For the use of these waters, it is necessary to take certain precautions. The pH values varied between 6.15 and 7.78, an average of 6.77 giving some waters an aggressive character. It was low mineralized, with electrical conductivity averages ranging from 182.1 to 2100 μS/cm−1 an average of 586.36 μS/cm−1. For the chemical parameters, it is by hydrometric titration that the content of the ions was determined. The determination of the various coliforms in these waters was carried out by its various methods which led to detecting that the waters of Kouba Adougoul are turbid, and present high proportions of nitrates, iron and ammonium. The presence of pathogenic germs, such as total coliforms and thermo-tolerant coliforms in these waters, has been demonstrated. For their consumption, these waters deserve treatment beforehand. In the study area, the anthropogenic activities are considered the most serious sources of groundwater.展开更多
Water is a precious natural resource, essential for many uses (crucial for various purposes). Its use for food or hygiene purposes requires excellent physico-chemical and microbiological quality. The region has a high...Water is a precious natural resource, essential for many uses (crucial for various purposes). Its use for food or hygiene purposes requires excellent physico-chemical and microbiological quality. The region has a high population density compared to other cities in Chad. In order to determine the effect of latrines on groundwater quality in the N’Djamena city, specifically in the 5th district, 13 water points were selected for physicochemical and bacteriological analyses. Physico-chemical parameters such as pH, temperature and conductivity were measured in situ using a multi-parameter device. Major ion analysis was carried out at the Laboratoire National des Eaux in N’Djamena. Anions (Cl−, SO42−, NO3−) were analysed using a Dr6000 spectrophotometer, and cations (Ca2+, Mg2+, Na+, K+) using a flame photometer and a volumetric dosing method. The result show that, the pH ranged from 5.89 to 6.78, with an average of 6.40. EC values range from 441 µS/cm to 1647 µS/cm, with an average of 830.76 µS/cm. A temperature values vary from 29˚C to 32˚C, with an average of 30˚C. The turbidity values range from 0.48 NTU to 10.6 NTU, with an average of 2.30 NTU. Ca2+ range from 20.8 mg/L to 160 mg/L, with an average of 73.23 mg/L (20). Mg2+ ranged from 3.4 mg/L to 18 mg/L, with an average of 6.85 mg/L. The Na+ ranged from 1.8 mg/L to 14.5 mg/L with an average of 3.83 mg/L. The iron content ranges from 0.06 mg/L to 0.83 mg/L, with an average of 0.29 mg/L. The average values are compared with world health organisation (WHO) drinking water quality standards. The results of chemical analyses on the Piper diagram show that the dominant chemical facies are calcium-magnesium bicarbonate. Bacteriological parameters were analysed using the membrane filter method. The samples contained E. coli, total coliforms and aerobic flora in excess of the WHO norm. The microbiological analyses clearly confirmed a high concentration of germs in the borehole water. Because the distance between the latrines and the water points was not respected, the pathogenic germs reached the water table, making the groundwater unhealthy. As a result, suitable water treatment is required before drinking form.展开更多
Length-weight relationships and condition factors are among the commonly used parameters to link the length of a fish to its weight. The present study was initiated to find out the growth patterns and overweight statu...Length-weight relationships and condition factors are among the commonly used parameters to link the length of a fish to its weight. The present study was initiated to find out the growth patterns and overweight status of 15 fish species in the Loémé basin in Mayombe, Republic of Congo. In the period from February 2020 to September 2021, sampling was carried out in eight stations, following a standardised capture method using four gillnets of 10, 12, 15, and 25 mm mesh size and a hawk net of 1.90 m radius with 10 mm mesh size. Length-weight relationships were calculated according to P = aLS<sup>b</sup> and the condition factor, using K = (P/LS<sup>b</sup>)* 100. A total of 1153 specimens representing 15 species, 10 genera and 6 families were recorded. The number of specimens ranged from 10 to 214 for Chrysichthys auratus and Enteromius camptacanthus, respectively. The allometry coefficient b minimum of 2.697 for Chromidotilapiamelaniae and maximum of 3.589 for Garraornata, with a mean of 3.03 ± 0.2 is significantly not different from 3 at the 0.05 probability threshold and indicates isometric growth for almost all species, except for E. camptacanthus where b = 2.858 was statistically different from 3 at the same threshold. The positive and high values of the coefficients of determination r<sup>2</sup> = 0.787-0.989 of the species, obtained during this study, suggest that weight increases with size in the fish of the Loémé basin. The average condition factor varies from 0.524 ± 0.064 for G. ornata to 4.917 ± 0.440 for C. melaniae.展开更多
The work carried out here opens another perspective in the valorization of sw<span>eet potatoes produced in Congo Brazzaville other than those proposed by <b><i>BOULA</i></b> <b><...The work carried out here opens another perspective in the valorization of sw<span>eet potatoes produced in Congo Brazzaville other than those proposed by <b><i>BOULA</i></b> <b><i>and</i></b><span> <b><i>all</i></b></span>. We have shown in this work that the hydrophilic property of starch which limits the production of starch-based bioplastics can be inhibited by using the effects of photonic incandescence. Indeed, light significantly impacts the bioplastic matrix causing a decrease of the sites likely to bind water molecules. However, it would be desirable to apply rheology for a better follow-up of this cross-linking phenomenon. The synthesized retrograde bioplastic having undergone a photonic stress shows better physical properties to be used as packaging and thus to answer the environmental protection.展开更多
The increasing production of wastewater and excreta presents a significant management challenge in the city of Bukavu,in Democratic Republic of the Congo(DRC).The objective of this study was to evaluate the causes and...The increasing production of wastewater and excreta presents a significant management challenge in the city of Bukavu,in Democratic Republic of the Congo(DRC).The objective of this study was to evaluate the causes and con-sequences of poor wastewater and excreta management and their associated environmental risks in Bukavu.This study was conducted from October 15 to November 18,2023,and encompassed 1210 households across the three mu-nicipalities of Bukavu.The research was carried out through field surveys,in-terviews,observations,and documentary analysis.The findings revealed that the majority of households(66%)are owner-occupied,compared to 21%by tenants.In the Bagira municipality,most households utilize manually flushed latrines(47%),whereas the use of modern toilets and pit latrines predominates in the Ibanda(67%)and Kadutu(70%)municipalities,respectively.Common disposal sites for fecal sludge include designated pits(65%),nearby canals(20%),and rivers and lakes(15%).Furthermore,over 60%of households in Bagira and more than 80%in Kadutu discharge their wastewater into open drainage channels,while over 65%of households in Ibanda discharge it into soak pits.Wastewater serves as a breeding ground for mosquitoes,which are vectors of malaria,the most prevalent disease in Bukavu.The results indicate that wastewater and excreta are predominantly managed in an unsanitary man-ner and are discharged into the environment.Pearson’s Chi-square test indi-cated a statistically significant difference(p<0.05)in wastewater discharge lo-cations across the municipalities of Bukavu.It is imperative to intensify public awareness campaigns about the detrimental consequences of improper waste-water and excreta disposal.展开更多
The Water Cherenkov Detector Array(WCDA) is a major component of the Large High Altitude Air Shower Array Observatory(LHAASO), a new generation cosmic-ray experiment with unprecedented sensitivity, currently under con...The Water Cherenkov Detector Array(WCDA) is a major component of the Large High Altitude Air Shower Array Observatory(LHAASO), a new generation cosmic-ray experiment with unprecedented sensitivity, currently under construction. WCDA is aimed at the study of TeV γ-rays. In order to evaluate the prospects of searching for TeV γ-ray sources with WCDA, we present a projection of the one-year sensitivity of WCDA to TeV γ-ray sources from TeVCat using an all-sky approach. Out of 128 TeVCat sources observable by WCDA up to a zenith angle of 45°, we estimate that 42 would be detectable in one year of observations at a median energy of 1 TeV. Most of them are Galactic sources, and the extragalactic sources are Active Galactic Nuclei(AGN).展开更多
Purpose Observation of high energy and very high emission from Gamma Ray Bursts(GRBs)is crucial to study the gigantic explosion and the underline processes.With a large field-of-view and almost full duty cycle,the Wat...Purpose Observation of high energy and very high emission from Gamma Ray Bursts(GRBs)is crucial to study the gigantic explosion and the underline processes.With a large field-of-view and almost full duty cycle,the Water Cherenkov Detector Array(WCDA),a sub-array of the Large High Altitude Air Shower Observatory(LHAASO),is appropriate to monitor the very high energy emission from unpredictable transients such as GRBs.Method Nevertheless,the main issue for an extensive air shower array is the high energy threshold which limits the horizon of the detector.To address this issue a new trigger method is developed in this article to lower the energy threshold of WCDA for GRB observation.Result The proposed method significantly improves the detection efficiency of WCDA for gamma-rays around the GRB direction at 10-300 GeV.The sensitivity of the WCDA for GRB detection with the new trigger method is estimated.The achieved sensitivity of the quarter WCDA array above 10 GeV is comparable with that of Fermi-LAT.The data analysis process and corresponding fluence upper limit for GRB 190719C is presented as an example.展开更多
The first Water Cherenkov detector of the LHAASO experiment(WCDA-1)has been operating since April 2019.The data for the first year have been analyzed to test its performance by observing the Crab Nebula as a standard ...The first Water Cherenkov detector of the LHAASO experiment(WCDA-1)has been operating since April 2019.The data for the first year have been analyzed to test its performance by observing the Crab Nebula as a standard candle.The WCDA-1 achieves a sensitivity of 65 mCU per year,with a statistical threshold of 5 cr.To accomplish this,a 97.7%cosmic-ray background rejection rate around 1 TeV and 99.8%around 6 TeV with an ap proximate photon acceptance of 50%is achieved after applying an algorithm to separate gamma-induced showers.The angular resolution is measured using the Crab Nebula as a point source to be approximately 0.45°at 1 TeV and better than 0.2°above 6 TeV,with a pointing accuracy better than 0.05°.These values all match the design specifications.The energy resolution is found to be 33%for gamma rays around 6 TeV.The spectral energy distribution of the Crab Nebula in the range from 500 GeV to 15.8 TeV is measured and found to be in agreement with the results from other TeV gamma ray observatories.展开更多
In the first part of this Chapter the present state of knowledge from the observations of cosmic rays between 10^(13) and 10^(20) eV is summarized.This is not intended to be a complete review,but rather a broad overvi...In the first part of this Chapter the present state of knowledge from the observations of cosmic rays between 10^(13) and 10^(20) eV is summarized.This is not intended to be a complete review,but rather a broad overview of the relevant processes involving cosmic rays,including the astrophysical environments in which they take place.This overview mainly concerns experimental results and phenomenological aspects of their interpretation,therefore experiments’description is not given but references to the vast bibliography are provided in the text.Some attempt is made to address the most popular explanations offered by theoretical models.The second part is devoted to the description of the LHAASO performance and of its capability to provide a response to several open questions,still unanswered,concerning cosmic rays above 10^(13) eV,highlighting which major steps forward in this field could be taken from LHAASO observations.展开更多
The LHAASO-WFCTA experiment,which aims to observe cosmic rays in the sub-EeV range using the fluorescence technique,uses a new generation of high-performance telescopes.To ensure that the experiment has ex-cellent det...The LHAASO-WFCTA experiment,which aims to observe cosmic rays in the sub-EeV range using the fluorescence technique,uses a new generation of high-performance telescopes.To ensure that the experiment has ex-cellent detection capability associated with the measurement of the energy spectrum,the primary composition of cosmic rays,and so on,an accurate geometrical reconstruction of air-shower events is fundamental.This paper de-scribes the development and testing of geometrical reconstruction for stereo viewed events using the WFCTA(Wide Field of view Cherenkov/Fluorescence Telescope Array)detectors.Two approaches,which take full advantage ofthe WFCTA detectors.are investigated.One is the stereo-angular method,which uses the pointing of triggered SiPMs in the shower trajectory,and the other is the stereo-timing method,which uses the triggering time of the fired SiPMs.The results show that both methods have good geometrical resolution:the resolution of the stereo-timing method is slightly better than the stereo-angular method because the resolution of the latter is slightly limited by the shower track length.展开更多
文摘The chemical composition of the volatile components of the dried roots of Scorzonera undulata ssp deliciosa collected from Algeria was determined by GC and GC/MS. The obtained results showed that the extracted oil contained nine fatty acids. The major compounds were hexadecanoic acid (42.2%), n-tetradecanoic acid (16.1%), 9-octadecenoic acid (7.7%) and 9-hexadecenoic acid (4.5%).
文摘The one dimensional Schrodinger equation associated with a time-dependent Morse potentials is studied. We use the invariant operator method （Lewis and Riesenfeld） to obtain approximate solution of the Schrodinger equation in terms of solution of second order ordinary differential equation describes the amplitude of the Morse potentials.
文摘In this paper we show that, under some conditions, if M is a manifold with Bakry-émery Ricci curvature bounded below and with bounded potential function then M is compact. We also establish a volume comparison theorem for manifolds with nonnegative Bakry-émery Ricci curvature which allows us to prove a topolological rigidity theorem for such manifolds.
文摘The original online version of this article (Issa Allassane Kaboye, Bazanfaré Mahaman (2016) Manifolds with Bakry-Emery Ricci Curvature bounded below 6, 754-764. http://dx.doi.org/10.4236/apm.2016.611061 unfortunately contains a mistake. The author wishes to correct the errors.
文摘Mathematical modeling plays a crucial role in understanding the dynamics of malaria transmission and can provide valuable insights for designing effective control strategies. Malaria indeed faces significant challenges due to a changing climate, particularly in regions where the disease is endemic. This disease is significantly impacted by changes in climate, especially rising temperatures and fluctuating rainfall patterns. This study explores the influence of temperature and rainfall abundance on malaria transmission dynamics within the context of Burundi. We have constructed a deterministic model that integrates these climatic parameters into the dynamics of the human host-mosquito vector system. The model’s steady states and basic reproduction number, calculated using the next-generation method, reveal important insights. Numerical simulations demonstrate that both temperature and rainfall significantly influence mosquito population dynamics, leading to distinct effects on malaria transmission. Specifically, we observe that temperatures between 20˚C and 32˚C, along with rainfall ranging from 10 to 30 mm per month, create optimal conditions for mosquito development, thus driving malaria transmission in Burundi. Furthermore, our findings indicate a delayed relationship between rainfall and malaria cases. When rainfall peaks in a given month, malaria does not peak immediately but instead shows a lagged response. Similarly, when rainfall decreases, malaria incidence drops after a certain time lag. This same lagged effect is observed when comparing temperature with confirmed malaria cases in Burundi. These findings highlight the urgent need to consider climate factors in malaria control strategies.
文摘Spinel-bearing lherzolite xenoliths from the Hossere Garba (1272 m.a.s.l) volcano on the Adamawa Plateau, is located in Likok village, at about 35 km to WSW of Ngaoundere. These xenoliths (~11 cm size) have been sampled into the host basaltic lava flows from the NE flank of the Hossere Garba volcano. These xenoliths characterized by porphyroclastic texture consisted of olivine (~55 vol.%), orthopyroxene (~19 vol.%) and clinopyroxene (~21 vol.%) crystals. Spinel crystals (~5 vol.%) are red brown and interstitial between the crystals of olivine and pyroxenes. CaO contents are low (<0.08 wt%) in olivine and similar to those estimated (CaO: 0.05 - 0.1 wt%) for the mantle origin. The values of AlVI/AlIV ratio range between 1.1 and 1.3 for the Cr-diopside crystals from Hossere Garba xenoliths. The constant value of the volumes V(Cell) and V(M1) for clinopyroxene compositions, indicates the similar pressures. Hossere Garba represents a residual sequence issued from partial melting of a mantle source. Similar compositions have been recorded in minerals of ultramafic xenoliths from other ultramafic xenoliths domains of the Cameroon Line and the Adamawa Plateau.
文摘We report the electrosynthesis of a novel semiconductor polymer based on alkyl vinylthiophene derivative in the presence of an ionic liquid (IL). The polymerization was performed under galvanostatic conditions and the polymer was studied as potential donor component of a multilayer heterojunction organic solar cell (OSC). The monomer used was (E)-1,2-di-(3-octyl-2-thienyl) vinylene (OTV) and the IL used for the electropolymerization was 1-octyl-3-methylimidazole hexafluorophosphate C8mimPF6. Optical properties, stability and morphology of the polymer were analyzed using FT-IR, UV-vis, Raman and XPS spectroscopy. Voltammetry analysis and scanning electron microscopy (SEM-EDX) were also performed on the polymer. The OSC assembled with the polymer of OTV was used as electro donor and C60 as acceptor. Molybdenum trioxide (MoO3) and bathocuproine (BCP) were used as buffer layer between anode and cathode respectively. I-V curves, in the dark and under AM 1.5 solar simulator were performed to measure its efficiency.
文摘Goal: The present study aimed to determine the profile of seric calcium and magnesium in pre-eclamptic and eclamptic pregnant women of Kinshasa province in the Democratic Republic of Congo where preeclampsia is characterized not only by a high incidence, but also by a seasonal variation probably related to nutritional intake. Study Design: This is a case-control study that took place during the period from September 2014 to March 2015 in four quaternary and tertiary maternity hospitals in Kinshasa. A total of 113 healthy pregnant women (controls) and 112 pre-eclamptic and eclamptic pregnant women (cases) were included in this study. Seric calcium and magnesium were measured in all these gravidas by the principle of spectrophotometry with a HUMALYSER Primus semi-automaton. Results: The mean age of those gravidas was 26.8 ± 6.3 years (26.7 vs 26.9, p = 0.11). The majority of these gravidas were primiparous. The mean gestational age in both groups was 31.35 ± 0.9 weeks (32.1 vs 30.6, p = 0.21). The average seric calcium value was 4.47 ± 0.23 mEq /L in healthy pregnant women compared to 3.80 ± 0.71 mEq/l in pre-eclamptics (P 0.001). The mean of seric magnesium was 1.56 ± 0.15 mg/dL in healthy pregnant women compared to 1.20 ± 0.41 mg/dL in pre eclamptics (P 0.001). Seric calcium and magnesium values were low in the pre-eclamptic group and lower in the eclamptic group (P 0.001). Conclusion: This study establishes a relationship between the low concentration of seric calcium and magnesium with pre-eclampsia and eclampsia, which could be one of the determinants of the high prevalence and seasonality of the disease in Kinshasa.
文摘<strong>Background: </strong>Parasitic diseases are threat to the development of Ivorian Pig industry. Zoonotic diseases such as Echinococcosis have a significant impact on animal health and production. Little is known about Echinococcosis in C<span style="white-space:nowrap;">ô </span>te d’Ivoire. <strong>Aim:</strong> For these reasons, a cross section study was conducted at SIVAC in Yopougon, on pigs (<em>Sus scrofa domesticus</em>), in order to determine the prevalence and associated risk factors of Echinococcosis. <strong>Method:</strong> Paraclinical examinations of pig organs (kidneys, lungs, and liver) were conducted from 5<sup>th</sup> September to 30<sup>th</sup> December 2019 in order to report infection with this parasite. <strong>Results:</strong> Out of the 2425 slaughtered pigs, 63 of them were Echi-nococcosis positive, resulting in overall infection prevalence of 2.6% (95% CI: 1.9% - 3.22%). The kidneys (2.35%) were most infected, followed by lungs (0.21%), and liver (0.04%). <strong>Recommendations: </strong>A more in-depth study on the molecular epidemiology of Echinococcosis in the different regions of C<span style="white-space:nowrap;">ô </span>te d’Ivoire is underway. Also, capacity building of community livestock actors (Veterinarians, health inspectors, breeders and butchers) and sensitization of the population on this disease is necessary in order to improve its diagnosis at the abattoir level and to set up strategies to combat it.
文摘Water is an essential element for all forms of life. The quantity and quality of water are a problem in places. In Kouba Adougoul and its surroundings in south guera, water-related health problems are reported. That is why this study focuses on the quality of water in the basement areas, of Kouba Adougoul. Our objective is to contribute to a better understanding of water of human consumption in these areas for this, we carried out a physicochemical and bacteriological control on a number water point. Ten water points were collected during May 2022 for analysis. To achieve this objective, we made the in-situ analysis of physical parameters such as pH, electrical conductivity, and temperature. These measurements were made using the multi-parameter kit. The result shows that, the water temperatures vary from 24.4˚C to 27.4˚C proving that the waters are from deep depths. For the use of these waters, it is necessary to take certain precautions. The pH values varied between 6.15 and 7.78, an average of 6.77 giving some waters an aggressive character. It was low mineralized, with electrical conductivity averages ranging from 182.1 to 2100 μS/cm−1 an average of 586.36 μS/cm−1. For the chemical parameters, it is by hydrometric titration that the content of the ions was determined. The determination of the various coliforms in these waters was carried out by its various methods which led to detecting that the waters of Kouba Adougoul are turbid, and present high proportions of nitrates, iron and ammonium. The presence of pathogenic germs, such as total coliforms and thermo-tolerant coliforms in these waters, has been demonstrated. For their consumption, these waters deserve treatment beforehand. In the study area, the anthropogenic activities are considered the most serious sources of groundwater.
文摘Water is a precious natural resource, essential for many uses (crucial for various purposes). Its use for food or hygiene purposes requires excellent physico-chemical and microbiological quality. The region has a high population density compared to other cities in Chad. In order to determine the effect of latrines on groundwater quality in the N’Djamena city, specifically in the 5th district, 13 water points were selected for physicochemical and bacteriological analyses. Physico-chemical parameters such as pH, temperature and conductivity were measured in situ using a multi-parameter device. Major ion analysis was carried out at the Laboratoire National des Eaux in N’Djamena. Anions (Cl−, SO42−, NO3−) were analysed using a Dr6000 spectrophotometer, and cations (Ca2+, Mg2+, Na+, K+) using a flame photometer and a volumetric dosing method. The result show that, the pH ranged from 5.89 to 6.78, with an average of 6.40. EC values range from 441 µS/cm to 1647 µS/cm, with an average of 830.76 µS/cm. A temperature values vary from 29˚C to 32˚C, with an average of 30˚C. The turbidity values range from 0.48 NTU to 10.6 NTU, with an average of 2.30 NTU. Ca2+ range from 20.8 mg/L to 160 mg/L, with an average of 73.23 mg/L (20). Mg2+ ranged from 3.4 mg/L to 18 mg/L, with an average of 6.85 mg/L. The Na+ ranged from 1.8 mg/L to 14.5 mg/L with an average of 3.83 mg/L. The iron content ranges from 0.06 mg/L to 0.83 mg/L, with an average of 0.29 mg/L. The average values are compared with world health organisation (WHO) drinking water quality standards. The results of chemical analyses on the Piper diagram show that the dominant chemical facies are calcium-magnesium bicarbonate. Bacteriological parameters were analysed using the membrane filter method. The samples contained E. coli, total coliforms and aerobic flora in excess of the WHO norm. The microbiological analyses clearly confirmed a high concentration of germs in the borehole water. Because the distance between the latrines and the water points was not respected, the pathogenic germs reached the water table, making the groundwater unhealthy. As a result, suitable water treatment is required before drinking form.
文摘Length-weight relationships and condition factors are among the commonly used parameters to link the length of a fish to its weight. The present study was initiated to find out the growth patterns and overweight status of 15 fish species in the Loémé basin in Mayombe, Republic of Congo. In the period from February 2020 to September 2021, sampling was carried out in eight stations, following a standardised capture method using four gillnets of 10, 12, 15, and 25 mm mesh size and a hawk net of 1.90 m radius with 10 mm mesh size. Length-weight relationships were calculated according to P = aLS<sup>b</sup> and the condition factor, using K = (P/LS<sup>b</sup>)* 100. A total of 1153 specimens representing 15 species, 10 genera and 6 families were recorded. The number of specimens ranged from 10 to 214 for Chrysichthys auratus and Enteromius camptacanthus, respectively. The allometry coefficient b minimum of 2.697 for Chromidotilapiamelaniae and maximum of 3.589 for Garraornata, with a mean of 3.03 ± 0.2 is significantly not different from 3 at the 0.05 probability threshold and indicates isometric growth for almost all species, except for E. camptacanthus where b = 2.858 was statistically different from 3 at the same threshold. The positive and high values of the coefficients of determination r<sup>2</sup> = 0.787-0.989 of the species, obtained during this study, suggest that weight increases with size in the fish of the Loémé basin. The average condition factor varies from 0.524 ± 0.064 for G. ornata to 4.917 ± 0.440 for C. melaniae.
文摘The work carried out here opens another perspective in the valorization of sw<span>eet potatoes produced in Congo Brazzaville other than those proposed by <b><i>BOULA</i></b> <b><i>and</i></b><span> <b><i>all</i></b></span>. We have shown in this work that the hydrophilic property of starch which limits the production of starch-based bioplastics can be inhibited by using the effects of photonic incandescence. Indeed, light significantly impacts the bioplastic matrix causing a decrease of the sites likely to bind water molecules. However, it would be desirable to apply rheology for a better follow-up of this cross-linking phenomenon. The synthesized retrograde bioplastic having undergone a photonic stress shows better physical properties to be used as packaging and thus to answer the environmental protection.
文摘The increasing production of wastewater and excreta presents a significant management challenge in the city of Bukavu,in Democratic Republic of the Congo(DRC).The objective of this study was to evaluate the causes and con-sequences of poor wastewater and excreta management and their associated environmental risks in Bukavu.This study was conducted from October 15 to November 18,2023,and encompassed 1210 households across the three mu-nicipalities of Bukavu.The research was carried out through field surveys,in-terviews,observations,and documentary analysis.The findings revealed that the majority of households(66%)are owner-occupied,compared to 21%by tenants.In the Bagira municipality,most households utilize manually flushed latrines(47%),whereas the use of modern toilets and pit latrines predominates in the Ibanda(67%)and Kadutu(70%)municipalities,respectively.Common disposal sites for fecal sludge include designated pits(65%),nearby canals(20%),and rivers and lakes(15%).Furthermore,over 60%of households in Bagira and more than 80%in Kadutu discharge their wastewater into open drainage channels,while over 65%of households in Ibanda discharge it into soak pits.Wastewater serves as a breeding ground for mosquitoes,which are vectors of malaria,the most prevalent disease in Bukavu.The results indicate that wastewater and excreta are predominantly managed in an unsanitary man-ner and are discharged into the environment.Pearson’s Chi-square test indi-cated a statistically significant difference(p<0.05)in wastewater discharge lo-cations across the municipalities of Bukavu.It is imperative to intensify public awareness campaigns about the detrimental consequences of improper waste-water and excreta disposal.
基金Supported by National Natural Science Foundation of China(11761141001,11635011,11873005)The LHAASO project is supported by the National Key R&D Program of China(2018YFA0404200),the Chinese Academy of Sciences,the Key Laboratory of Particle Astrophysics,IHEP,CAS。
文摘The Water Cherenkov Detector Array(WCDA) is a major component of the Large High Altitude Air Shower Array Observatory(LHAASO), a new generation cosmic-ray experiment with unprecedented sensitivity, currently under construction. WCDA is aimed at the study of TeV γ-rays. In order to evaluate the prospects of searching for TeV γ-ray sources with WCDA, we present a projection of the one-year sensitivity of WCDA to TeV γ-ray sources from TeVCat using an all-sky approach. Out of 128 TeVCat sources observable by WCDA up to a zenith angle of 45°, we estimate that 42 would be detectable in one year of observations at a median energy of 1 TeV. Most of them are Galactic sources, and the extragalactic sources are Active Galactic Nuclei(AGN).
基金This work is supported by the National Key R&D Program of China under the Grant 2018YFA0404201the Natural Sciences Foundation of China under the Grants 12022502,11635011the Key R&D Program of SiChuan Province under the Grant 2019ZYZF0001.
文摘Purpose Observation of high energy and very high emission from Gamma Ray Bursts(GRBs)is crucial to study the gigantic explosion and the underline processes.With a large field-of-view and almost full duty cycle,the Water Cherenkov Detector Array(WCDA),a sub-array of the Large High Altitude Air Shower Observatory(LHAASO),is appropriate to monitor the very high energy emission from unpredictable transients such as GRBs.Method Nevertheless,the main issue for an extensive air shower array is the high energy threshold which limits the horizon of the detector.To address this issue a new trigger method is developed in this article to lower the energy threshold of WCDA for GRB observation.Result The proposed method significantly improves the detection efficiency of WCDA for gamma-rays around the GRB direction at 10-300 GeV.The sensitivity of the WCDA for GRB detection with the new trigger method is estimated.The achieved sensitivity of the quarter WCDA array above 10 GeV is comparable with that of Fermi-LAT.The data analysis process and corresponding fluence upper limit for GRB 190719C is presented as an example.
基金Supported by the following grants:the National Key R&D program of China(2018YFA0404201,2018YFA0404202,2018YFA0404203)the National Natural Science Foundation of China(12022502,11905227,U1931112,11635011,11761141001,Y811A35,11675187,U1831208,U1931111)in Thailand by RTA6280002 from Thailand Science Research and Innovation。
文摘The first Water Cherenkov detector of the LHAASO experiment(WCDA-1)has been operating since April 2019.The data for the first year have been analyzed to test its performance by observing the Crab Nebula as a standard candle.The WCDA-1 achieves a sensitivity of 65 mCU per year,with a statistical threshold of 5 cr.To accomplish this,a 97.7%cosmic-ray background rejection rate around 1 TeV and 99.8%around 6 TeV with an ap proximate photon acceptance of 50%is achieved after applying an algorithm to separate gamma-induced showers.The angular resolution is measured using the Crab Nebula as a point source to be approximately 0.45°at 1 TeV and better than 0.2°above 6 TeV,with a pointing accuracy better than 0.05°.These values all match the design specifications.The energy resolution is found to be 33%for gamma rays around 6 TeV.The spectral energy distribution of the Crab Nebula in the range from 500 GeV to 15.8 TeV is measured and found to be in agreement with the results from other TeV gamma ray observatories.
基金Supported by the National Key R&D Program of China(2018YFA0404203)the International Scholarship Program of the MOST of China(G2021166002L)+1 种基金National Natural Science Foundation of China(NSFC)(12147208,U2031103,U1931204)the Science and Technology Department of Sichuan Province(2021YFSY0031)。
文摘In the first part of this Chapter the present state of knowledge from the observations of cosmic rays between 10^(13) and 10^(20) eV is summarized.This is not intended to be a complete review,but rather a broad overview of the relevant processes involving cosmic rays,including the astrophysical environments in which they take place.This overview mainly concerns experimental results and phenomenological aspects of their interpretation,therefore experiments’description is not given but references to the vast bibliography are provided in the text.Some attempt is made to address the most popular explanations offered by theoretical models.The second part is devoted to the description of the LHAASO performance and of its capability to provide a response to several open questions,still unanswered,concerning cosmic rays above 10^(13) eV,highlighting which major steps forward in this field could be taken from LHAASO observations.
基金National Natural Science Foundation of China(11903005,11563004,11475190)。
文摘The LHAASO-WFCTA experiment,which aims to observe cosmic rays in the sub-EeV range using the fluorescence technique,uses a new generation of high-performance telescopes.To ensure that the experiment has ex-cellent detection capability associated with the measurement of the energy spectrum,the primary composition of cosmic rays,and so on,an accurate geometrical reconstruction of air-shower events is fundamental.This paper de-scribes the development and testing of geometrical reconstruction for stereo viewed events using the WFCTA(Wide Field of view Cherenkov/Fluorescence Telescope Array)detectors.Two approaches,which take full advantage ofthe WFCTA detectors.are investigated.One is the stereo-angular method,which uses the pointing of triggered SiPMs in the shower trajectory,and the other is the stereo-timing method,which uses the triggering time of the fired SiPMs.The results show that both methods have good geometrical resolution:the resolution of the stereo-timing method is slightly better than the stereo-angular method because the resolution of the latter is slightly limited by the shower track length.
