This study introduces and evaluates a novel artificial hummingbird algorithm-optimised boosted tree(AHAboosted)model for predicting the dynamic modulus(E*)of hot mix asphalt concrete.Using a substantial dataset from N...This study introduces and evaluates a novel artificial hummingbird algorithm-optimised boosted tree(AHAboosted)model for predicting the dynamic modulus(E*)of hot mix asphalt concrete.Using a substantial dataset from NCHRP Report-547,the model was trained and rigorously tested.Performance metrics,specifically RMSE,MAE,and R2,were employed to assess the model's predictive accuracy,robustness,and generalisability.When benchmarked against well-established models like support vector machines(SVM)and gaussian process regression(GPR),the AHA-boosted model demonstrated enhanced performance.It achieved R2 values of 0.997 in training and 0.974 in testing,using the traditional Witczak NCHRP 1-40D model inputs.Incorporating features such as test temperature,frequency,and asphalt content led to a 1.23%increase in the test R2,signifying an improvement in the model's accuracy.The study also explored feature importance and sensitivity through SHAP and permutation importance plots,highlighting binder complex modulus|G*|as a key predictor.Although the AHA-boosted model shows promise,a slight decrease in R2 from training to testing indicates a need for further validation.Overall,this study confirms the AHA-boosted model as a highly accurate and robust tool for predicting the dynamic modulus of hot mix asphalt concrete,making it a valuable asset for pavement engineering.展开更多
Introduction: Endoscopic internal urethrotomy (EIU) is a method for stricture opening using transurethral incision by direct visualisation of the urethral channel, resulting in a widening of the urinary canal with the...Introduction: Endoscopic internal urethrotomy (EIU) is a method for stricture opening using transurethral incision by direct visualisation of the urethral channel, resulting in a widening of the urinary canal with the aim of improving the quality of bladder emptying. The aim of the study was to evaluate the indication and results of EIU in the treatment of stenosis of the male urethra in the Urology-Andrology Department of Kara Teaching Hospital. Methodology: This was a cross-sectional descriptive study with retrospective data collection in the Urology-Andrology department of Kara Teaching Hospital. It involved 21 records of patients with urethral stenosis treated by endoscopic internal urethrotomy (EIU) in the said department during the period from January 2021 to September 2023. The following variables were evaluated: age, circumstance of discovery, site, length, number, etiology of the urethral stenosis and evolution of the patients. Results: The mean age of the patients was 59.2 ± 11.7 years. Infectious etiology of stenosis was predominant with 10 patients (47.6%) followed by trauma with 5 cases (23.8%). The bulbar urethra was the most frequently observed site, with 11 cases (52.4%). The length was mostly less than 2 cm in 12 patients (57.1%). Stenosis was unique in 14 patients (66.7%). The mean postoperative follow-up time was 3.2 months. The result was immediately better in 11 patients (52.4%) and it was poor in 8 patients (38.1%) who required maintenance dilation sessions.展开更多
The interest of this conference is agricultural, environmental, bioenergetics, and sanitary. In that context, domestic, agricultural and industrial environments produce organic waste, which needs to be collected, sele...The interest of this conference is agricultural, environmental, bioenergetics, and sanitary. In that context, domestic, agricultural and industrial environments produce organic waste, which needs to be collected, selected, stored and recycled properly in order to avoid environmental pollution and promote agriculture. The green Industry proposed involves the conversion of natural, non-toxic organic waste in order to efficiently produce organic fertilizers for agriculture. These types of fertilizers from biological origin are suitable because they are not toxic for human and the environment. Enzymatic reactions described in this presentation concern mainly the hydrolysis of proteins, sugars and lipids, the acidification of intermediate products from hydrolysis, the formation of acetate, and the production of methane. In other words, this review is timely as it discusses for the chemical behavior or the reactivity of different functional groups to better understand the enzymatic catalysis in the transformations of residual proteins, carbohydrates, and lipids to generate biomethane and fertilizers. In the same perspective, this review is to enrich the documentation related to organic reactions catalyzed by enzymes, which occur in the anaerobic degradation of residual organic substances, with emphasis on the structures of organic compounds and reaction mechanisms. This will allow understanding the displacement of the electrons of a reactive entity rich in electrons to another reactive entity that is poor in electrons to form new bonds in products.展开更多
This study focuses on the determination of physical and mechanical characteristics based on in vitro tests, by using field samples for the Kampemba urban area in the city of Lubumbashi. At the end of this study, we id...This study focuses on the determination of physical and mechanical characteristics based on in vitro tests, by using field samples for the Kampemba urban area in the city of Lubumbashi. At the end of this study, we identified the soils according to their parameters, and established the geotechnical classification by determining their bearing capacity by the group index method using from the identification tests carried out. By using the AASHTO classification method (American Association for State Highway Transportation Official), the results obtained after our studies revealed five classes of soil: A-2, A-4, A-5, A-6, A-7 in a general way, and particularly eight subgroups of soil: A-2-4, A-2-6, A-2-7, A-4, A-5, A-6, A-7-5 and A-7-6 for the concerned area. The latter has given statistical analysis and deep learning based on multi-layer perceptron, the global values of the physical parameters. It’s about: 31.77% ± 1.05% for the limit of liquidity;18.71% ± 0.76% for the plastic limit;13.06% ± 0.79% for the plasticity index;83.00% ± 3.33% for passing of 2 mm sieve;76.22% ± 3.2% for passing of 400 μm sieve;89.07% ± 2.99% for passing of 4.75 mm sieve;70.62% ± 2.39% passing of 80 μm sieve;1.66 ± 0.61 for the consistency index;<span style="white-space:nowrap;">−</span>0.67 ± 0.62 for the liquidity index and 8 ± 1 for the group index.展开更多
Pharmaceutical counterfeiting is a health scourge responsible for several cases of morbidity and mortality. Counterfeit medicines cause therapeutic failure, emergence of resistance in the treatment of infections. This...Pharmaceutical counterfeiting is a health scourge responsible for several cases of morbidity and mortality. Counterfeit medicines cause therapeutic failure, emergence of resistance in the treatment of infections. This study was conducted in order to identify counterfeit and authentic medicines in circulation in Lubumbashi. The study included artemether and artesunate for oral administration. A careful visual inspection of medicine, investigation of authenticity of pharmaceutical products from manufacturers and pharmaceutical regulatory authorities and determination of content were used as study parameters. 52 samples: 37 artemether and 15 of artésunate were collected. 7 samples (13%) have proven to be counterfeit. Artemether was the most counterfeit (71%) and 29% for artesunate. 6 (12%) samples were substandard according to the international pharmacopoeia in terms of content of active ingredient. Sixty-seven percent of non-compliance concerned counterfeit medicines. The proportion of non-compliance is highest among counterfeit medicines (71.43% vs 2.22%;p = 0.000004). It is obvious that strengthening the capacity of the drug regulatory authority of the DRC reduces the influx of counterfeit drug and substandard.展开更多
Spent cathode carbon(SCC)from aluminum electrolysis is a potential graphite resource.However,full use of the SCC remains a challenge,since it contains many hazardous substances(e.g.,fluoride salts,cyanides),encapsulat...Spent cathode carbon(SCC)from aluminum electrolysis is a potential graphite resource.However,full use of the SCC remains a challenge,since it contains many hazardous substances(e.g.,fluoride salts,cyanides),encapsulated within the thick carbon layers and thus posing serious environmental concerns.This work presents a chemical oxidative exfoliation route to achieve the recycling of SCC and the decontaminated SCC with high-valued graphene oxide(GO)-like carbon structures(SCC-GO)is applied as an excellent adsorbent for organic pollutants.Specifically,after the oxidative exfoliation,the embedded hazardous constituents are fully exposed,facilitating their subsequent removal by aqueous leaching.Moreover,benefiting from the enhanced specific surface areas along with abundant O-containing functional groups,the as-produced SCC-GO,shows an adsorption capacity as high as 347 mg·g^(-1)when considering methylene blue as a pollutant model,which exceeds most of the recently reported carbon-based adsorbents.Our study provides a feasible solution for the efficient recycling of hazardous carbonaceous wastes.展开更多
Trace metal levels of groundwater in Lubumbashi,Kampemba and Kamalondo communes of Lubumbashi city were assessed from October 2016 to February 2017.Two hundred forty water samples collected from twenty-two spade-sunk ...Trace metal levels of groundwater in Lubumbashi,Kampemba and Kamalondo communes of Lubumbashi city were assessed from October 2016 to February 2017.Two hundred forty water samples collected from twenty-two spade-sunk wells and twelve drilled wells in these three communes of Lubumbashi city were analyzed for their metal contents using ICP-SF-MS(Inductively Coupled Plasma-Sector Field Mass Spectrometry).Twenty trace elements including strontium,molybdenum,cadmium,cesium,barium,tungsten,thallium,lead,bismuth,uranium,aluminum,vanadium,chromium,manganese,iron,cobalt,nickel,copper,zinc and arsenic were recorded at varying concentrations in all the water samples and were compared with the WHO(World Health Organization),US EPA(Environmental Protection Agency)and EU(European Union)drinking water MCLs(Maximum Concentration Limits)for cadmium,barium,thallium,lead,uranium,aluminum,chromium,manganese,iron,nickel,copper,zinc and arsenic.Mean cadmium,lead,aluminum,manganese,iron,nickel,zinc and arsenic levels respectively exceeded the WHO,US EPA and EU drinking water MCLs in 6.66%,3.38%,26.67%,5.02%,30.03%,3.38%,1.64% and 5.02% of the samples with the highest mean levels of 116.89μg/L for cadmium,38.162μg/L for lead,2,712.5μg/L for aluminum,1,242.68μg/L for manganese,17,325.98μg/L for iron,64.647μg/L for nickel,9,900.72μg/L for zinc and 65.458μg/L for arsenic.Mean water pH values ranged from 4.7 to 11.1 with 19.17% of the groundwater samples having mean pH values outside the WHO drinking water pH optimum range values of 6.5-8.5,including 5.02% of the water samples which were acidic(mean pH values ranging from 4.7 to 6.4)and 14.15% which were alkaline(mean pH values ranging from 8.6 to 11.1).With such physicochemical and trace metal contamination status of groundwater in the three communes of Lubumbashi city,there is a high risk to the health of people who use that water to meet their drinking water needs.展开更多
<strong>Introduction:</strong> Geohelminths are infections due to various species of parasitic worms transmitted by eggs present in human excreta which contaminate the soil where sanitation is poor. The ob...<strong>Introduction:</strong> Geohelminths are infections due to various species of parasitic worms transmitted by eggs present in human excreta which contaminate the soil where sanitation is poor. The objective of this study was to analyse the determinants and knowledge on geo-helminthiasis among inmates and care providers in the Kassapa prison environment in Lubumbashi in the Demographic Republic of Congo. <strong>Methods:</strong> This is a cross-sectional descriptive study which was conducted from September 21 to October 15, 2020 in Kassapa prison in Demographic Republic of Congo. Estimates of the prevalence and general characteristics of geo-helminthiasis in prisoners were calculated by descriptive analyses. The analysis of determinants was performed based on a binary logistic regression. <strong>Results:</strong> With regard to the quantitative section, the study used a sample size of 1083 while a sample size of six was considered for the qualitative section. The annual prevalence of geo-helminthiasis was 10.2%, 4.8% and 2.9% respectively for 2017, 2018 and 2019. It was found that the general prevalence of geo-helminthiases was 17.9%. The age group above 39 years constitutes the modal class with 29.4%, the least affected age group being that of minors with 6.3%. The association is statistically significant between sex, treatment, prison residence and year. Thus, taking gender into account, women are by 2.3 (OR = 2.3, 95% CI [1.3%;4.8%], p value < 0.05) more likely to be at risk of suffering from geo-helminthiasis than men, and mebendazole is by 2.1 a better treatment of geo-helminthiasis than albendazole (OR = 2.1, 95% CI [1.1%;4.6%], p-value < 0.05). Transmission routes of geo-helminthiasis are relatively well known among these actors who have often reported eating dirty food, walking barefoot, and drinking dirty water. <strong>Conclusion:</strong> This descriptive cross-sectional study rounds off by pointing to poor hygiene, insufficient health education and a low socio-economic level exposing inmates to the risk of contracting geo-helminthiasis, particularly as prisoners in Kassapa live in a difficult situation and are therefore very vulnerable.展开更多
<strong>Objective:</strong> <span><span><span style="font-family:""><span style="font-family:Verdana;">To determine the psychosocial problems, social accept...<strong>Objective:</strong> <span><span><span style="font-family:""><span style="font-family:Verdana;">To determine the psychosocial problems, social acceptance and the impact of the costs of parents whose child has cancer. </span><b><span style="font-family:Verdana;">Method: </span></b><span style="font-family:Verdana;">We carried out a descriptive cross-sectional study over two-year periods (from January 3, 2018 to March 31, 2020) in the pediatric oncology unit of clinics at the University of Lubumbashi, in DR Congo. </span><b><span style="font-family:Verdana;">Results:</span></b><span style="font-family:Verdana;"> 129 parents of children with cancer in the pediatric oncology unit were included in our study. Most children with cancer (53%) were accompanied by their mothers who had a low level of education (53.0%). Emotional shock was the most observed reaction (68%) to the announcement of the disease (cancer). Retinoblastoma has had a significant economic impact on families without medical coverage. Only 38% received psychological support from parents. Sadness was the most common feeling (77%) of households. Support workers consider their relationship with the medical profession acceptable in 67% and difficult in 11%. The majority of parents (78%) felt that the time to provide medical care was longer than expected. </span><b><span style="font-family:Verdana;">Conclusion: </span></b><span style="font-family:Verdana;">Parents of children with cancer had different feelings and reactions. This observation may be useful for the development of a health policy, in particular that of pediatric cancer in DR Congo.</span></span></span></span>展开更多
<strong>Introduction:</strong> Noise, an undesirable sound which is found in all areas of occupational activity, is still a matter of concern given the damage it causes. Various machines and tools, from si...<strong>Introduction:</strong> Noise, an undesirable sound which is found in all areas of occupational activity, is still a matter of concern given the damage it causes. Various machines and tools, from simple to sophisticated ones, produce several types of noise in the workplace. The purpose of this study was to assess the current status of occupational hearing loss among informal sector welders in the city of Lubumbashi, in the Democratic Republic of Congo. <strong>Methods: </strong>This was a descriptive cross-sectional study which was conducted among 122 informal sector welders over a period of five months. The study used an anonymous questionnaire on noise exposure in the workplace and collected audio-metric data of welders. The survey collected data on welders who had a minimal three-year duration of employment without the morbidity associated with the Ear Nose Throat (ENT) region. Socio-professional data (age, duration of employment, sex, education), noise exposure, awareness of hazards and audiometric data were taken into account. <strong>Results:</strong> 122 questionnaires were completed by male subjects, or 100% (n = 122). The mean age of welders was 36.37 ± 11.91 years with extremes being 20 and 63 years. The mean duration of employment was 11.51 ± 9.6 years with extremes being 3 and 44 years. Audiometric data have shown 37.96% (n = 41) of occupational hearing loss. Three degrees of hearing loss were recorded, notably mild hearing loss standing at 80.49% (n = 33);moderate and severe hearing loss standing at 2.44% (n = 1). Ninety-six percent (n = 117) of welders reported not using personal protective equipment (PPE) and 1% (n = 111) were aware of the hazard associated with noise exposure in the workplace. A correlation was found between welders with an advanced age (p < 0.001;RP = 3.66 (2.16 - 6.22)) and hearing loss, and between the duration of employment and hearing loss (p < 0.001;RP = 6.48 (3.32 - 12.65)). <strong>Conclusion: </strong>In the study area, occupational hearing loss among welders is a relevant fact. Three degrees of hearing loss were identified. Most of those suffering from it have developed a mild type of hearing loss whose continued development can be stopped. Despite the fact that welders are aware of the hazards associated with noise exposure in the workplace, they hardly protect themselves. Lack of a culture of prevention and poor enforcement of the existing laws could account for such a situation. There seems to be a crucial need to put in place a program for protecting the welders’ auditory organs in the workplace.展开更多
Bushmeat is frequently consumed in households in the city of Lubumbashi in the Democratic Republic of Congo.Several studies in Africa show that this food is regularly consumed by rural and urban populations.This consu...Bushmeat is frequently consumed in households in the city of Lubumbashi in the Democratic Republic of Congo.Several studies in Africa show that this food is regularly consumed by rural and urban populations.This consumption is motivated by several reasons.These have never been elucidated in the city of Lubumbashi.This study aims to highlight the sociocultural aspects that justify the consumption of bushmeat in order to consider its sustainability.A survey was conducted among 1,400 households in the municipalities of the city.A questionnaire helped collect the information that was presented as a percentage.This information shows that 86.6%of the population consume monthly(41.3%)of bushmeat.This consumption is based on taste(51.7%).On the other hand,religious beliefs(29.2%)prevent this consumption.The order of the artiodactylsis is the most affected(74.2%).The recognition of the species consumed comes from the information provided by the sellers(58.5%).Bushmeat comes from the district of Haut-Katanga(35.2%).It is sold in the main markets of the city of Lubumbashi(67.9%).Bush meat is becoming an exhaustible natural resource,mechanisms and alternatives will need to be put in place to enable the sustainable conservation of wild animal species.展开更多
Introduction: Rabies, a neglected disease, could be grossly underreported in the DRC;in the absence of post-exposure prophylaxis, the WHO estimates that this disease would cause 327,000 deaths per year in Africa and A...Introduction: Rabies, a neglected disease, could be grossly underreported in the DRC;in the absence of post-exposure prophylaxis, the WHO estimates that this disease would cause 327,000 deaths per year in Africa and Asia. The objective of this study is to determine the epidemiological profile of this zoonosis in order to encourage decision-makers to develop national strategies for its elimination. Materials and Methods: We conducted a cross-sectional descriptive study. Data collection was done retrospectively and in total6 420 victims of bites received during the period between January 2005 and December 2015 at the anti-rabies center in Lubumbashi were included in this work. Excel 13 software and Epi info 3.3.4 were used for data analysis and interpretation. Results: People over the age of 15 are the main victims of canine bites (62.1%), more than half of the victims are male (55.9%);dogs represent the majority of biting animals (96.4%) of which around 3/4 are unvaccinated (71.37%). Two municipalities are more affected: Lubumbashi (prevalence 83.35/100,000 and Kampemba (Prevalence 51.74/100,000). LBite peaks were observed from July to October (p = 0.01). For the 34 people seen with clinical signs of rabies encephalitis (confirmed case of rabies), the case fatality rate was 100%. Conclusion: Rabies is a major problem in Lubumbashi but its extent is different depending on the municipality. The dog is the main biting animal and the vaccination coverage of dogs remains very low. Access to rabies vaccine for bite victims is difficult. Its elimination remains possible through the implementation of an extensive canine vaccination program, the awareness of owners and the large-scale provision of post-exposure prophylaxis.展开更多
Introduction: Public hospitals in the DRC are of significant disrepair, while there is a strong link between the failure of hospital hygiene and the incidence of nosocomial infections. We have conducted a study with t...Introduction: Public hospitals in the DRC are of significant disrepair, while there is a strong link between the failure of hospital hygiene and the incidence of nosocomial infections. We have conducted a study with the objective of evaluating the structural-functional conditions of hospital hygiene maternity wards of public hospitals in Lubumbashi. Methodology: It was a descriptive cross-sectional study and structural-functionalist whose population consisted of nurses responsible for 7 of 12 maternity hospitals which were selected based on the inclusion criteria. The observation with an observation guide and maintenance using a questionnaire we used to collect data. Results: The results showed that hospital hygiene conditions in maternity wards of public hospitals in Lubumbashi are not good because almost all maternity services and surgery are not always water in the taps (14.3%). The bins were a means for care units, no coding system exists to distinguish the type of waste. The medical waste are mixed and the other waste are burned in the open or in makeshift incinerator with other types of waste. Conclusion: These maternity wards have poor hygiene, staff responsible for this sector did not follow any training in this area. There is need to regulate the sector and train them.展开更多
Nanoparticles have distinct properties that make them potentially valuable in a variety of industries.As a result,emerging approaches for the manufacture of nanoparticles are gaining a lot of scientific interest.The b...Nanoparticles have distinct properties that make them potentially valuable in a variety of industries.As a result,emerging approaches for the manufacture of nanoparticles are gaining a lot of scientific interest.The biological pathway of nanoparticle synthesis has been suggested as an effective,affordable,and environmentally safe method.Synthesis of nanoparticles through physical and chemical processes uses unsafe materials,expensive equipment and adversely affects the environment.As a result,in order to support the increased utilization of nanoparticles across many sectors,nanotechnology research activities have shifted toward environmentally safe and cost-effective techniques that outperform chemical and/or biological procedures.The use of organisms to produce metal nanoparticles is among the most frequently discussed methods.Plants appear to be the best candidates among these organisms for large-scale nanoparticle biosynthesis.Medicinal plants have been employed as reducing agents and NP stabilizers to minimize the toxicity of NPs in both the environment and the human body.Furthermore,the presence of certain functional components in plant extracts may be extremely useful and effective for the human body.Polyphenol,for example,which may have antioxidant properties,might intercept free radicals before they interact with other biomolecules and cause considerable damage.The current article analyzes the most recent developments and improvements in the green synthesis of metal nanoparticles by different plants and the use of these nanoparticles for various biomedical applications and hopes to provide insights into this exciting research frontier.展开更多
The objective of the study was to identify the failure factors of community interventions in terms of HIV activities in the province of Haut-Katanga during the year 2016. Materials and Methods: The study was phenomeno...The objective of the study was to identify the failure factors of community interventions in terms of HIV activities in the province of Haut-Katanga during the year 2016. Materials and Methods: The study was phenomenological of the factors, carried out in Haut Katanga. All health facilities (FOSAs) having integrated the prevention of transmission of HIV infection from mother to child (PMTCT) were included in the study. The collection was carried out through individual semi-structured interviews with PMTCT focal points, mentor mothers and people living with HIV (PLWHA) cared for in some of these health facilities (FOSAs). The number of participants was determined by the saturation of responses. Nvivo v.11 software was used for the analyses. The data of each woman was handled confidentially. The authorization of the ethics committee of the University of Kinshasa ESP/CE091/2015, the free and written consent, was obtained before collecting the information. Results: It was observed the socio-cultural factors of success and failure of the interventions: the social fear generated by contradictory messages in the sensitization of the community;the lack of an obvious strategy for the involvement of the partner;the weak coordination of community care activities between the central office of the health zone;the FOSA and the community worker: low interest in community care evidenced by weak accountability of FOSAs, community and program providers in this regard;that relates to community activities;coordination of care between care units;overload of the staff in charge of activities within the health structure and their low motivation;the low communication time devoted to people living with HIV in the FOSAs. Conclusion: The study shows that interventions that can improve the quality and outcomes of prevention of mother-to-child transmission of HIV (PMTCT) services can be directly linked to the program itself, as well as come from another or the community, which generally remains the weak link in which efforts are even less noticeable, at least as far as PMTCT is concerned. Integrating care data for the mother-child couple improve the continuum of services between the different care units as well as the quality of data management.展开更多
Arsenic,barium,bismuth,cadmium,cesium,chromium,cobalt,copper,iron,lead,manganese,molybdenum,nickel,strontium,thallium,tungsten,uranium,vanadium,and zinc concentrations were investigated in forty-two groundwater sample...Arsenic,barium,bismuth,cadmium,cesium,chromium,cobalt,copper,iron,lead,manganese,molybdenum,nickel,strontium,thallium,tungsten,uranium,vanadium,and zinc concentrations were investigated in forty-two groundwater samples,twenty-four surface water and six surface sediment samples in Kinsevere industrial zone and its surroundings in February and march 2017,January,February and March 2018 to evaluate the potential human health risk.Chemical analyses were carried out by using ICP-SF-MS(Inductively Coupled Plasma-Sector Field Mass Spectrometry,Thermo Scientific Element II).The trace metals were detected at various concentrations in all the analyzed samples.Pb,Mn and Fe concentrations exceeded the European Union acceptable maximum limits for water intended for human consumption in 4.76%,28.57%and 61.90%of the groundwater samples,respectively and in 0%,50%and 100%of the surface water samples,respectively.As,Cr,Cu and Ni concentrations exceeded the recommended lower sediment quality guideline values in 33.33%,50%,83.33%and 83.33%of the surface sediment samples,respectively.All those elevated trace metal concentrations in the groundwater,surface water and sediments represent a risk for the health of local population as well as for aquatic organisms.展开更多
Environmental change is characterized as an alteration in the environment caused primarily by human activities and ecological processes that are natural. Given the fact that the southern part of the province of Haut-K...Environmental change is characterized as an alteration in the environment caused primarily by human activities and ecological processes that are natural. Given the fact that the southern part of the province of Haut-Katanga in the Democratic Republic of the Congo (DRC) is part of the African Copperbelt and has been a region of intense mining for decades, humans have affected the physical environment in various ways: such as overpopulation, suburbanization, wastage, deforestation. It is therefore important to track and control the changes in the area’s mining activities. This study aimed to analyze these changes using remote sensing techniques. Landsat satellite images from 2002 and 2022 were processed and classified to quantify changes in built-up area, agricultural land, and vegetation cover over the 20-year period. The classification results revealed sizable differences between the two time points, indicating considerable expansion of built-up land and declines in agricultural land and vegetation cover from 2002 to 2022 in Likasi. These findings provide evidence that urban growth has transformed the landscape in Likasi, likely at the expense of farmland and ecosystems. Further analysis of the remote sensing data could quantify the changes and model future trends to support sustainable land use planning. The land cover and land use analysis were performed with the assistance of the ERDAS 16.6.13 software by mapping LANDSAT data from two different years 2002 and 2022.展开更多
The Mokama granites are located in the Kibara belt (KIB) and hosts tin oxide group minerals (TOGM: Sn-W), and sulfide group minerals (SGM: Cu-Zn-Fe-As). The essential of Cu mineralization (non-economic deposit) is dis...The Mokama granites are located in the Kibara belt (KIB) and hosts tin oxide group minerals (TOGM: Sn-W), and sulfide group minerals (SGM: Cu-Zn-Fe-As). The essential of Cu mineralization (non-economic deposit) is disseminated inside the rock and consists of minerals (Raman, EPMA and metallographic microscopy) including chalcopyrite and bornite that are replaced by chalcocite and covellite, and the last also replaced later by malachite. The chemistry (XRF, LA-ICP-MS) of these peraluminous S-type leucogranites show SiO<sub>2</sub> (71 wt% - 79 wt%), ASI (1.4 - 3.1 molar), and are enriched in Rb (681 - 1000 ppm), Ta (12–151 ppm), Sn (43 - 142 ppm), Cu (10 - 4300 ppm), Zn (60 - 740 ppm), U (2.2 - 20.7 ppm) while depleted in Zr (20 - 31 ppm), Sr (20 - 69 ppm), Hf (1.3 - 2.0 ppm), Th (2.2 - 18.9 ppm), W (9 - 113 ppm), Pb (5 - 50 ppm), Ge (5 - 10 ppm), Cs (21 - 53 ppm) and Bi (0.6 - 17.4 ppm) and low ratios of (La/Yb) N, (Gd/Yb) N, (La/Sm) N). Fluid inclusion assemblages (FIAs) hosted in quartz in the Mokama granites show ranges of salinities of 4 - 23 wt% (NaCl equivalent) and homogenization temperatures (Th) of 190°C - 550°C. A boiling assemblage in the granite suggests a fluid phase separation occurred at about 380 - 610 bars, and this corresponds to apparent paleodepths of approximately 1 - 2 km (lithostatic model) or 3 - 5 km (hydrostatic model). FIAs hosted in TOGM such as cassiterite (salinities of 2 wt% - 10 wt% and Th of 220°C - 340°C) helped set up the possible temperature limit of SGM (Cu sulfide) precipitations that are estimated below 200°C.展开更多
文摘This study introduces and evaluates a novel artificial hummingbird algorithm-optimised boosted tree(AHAboosted)model for predicting the dynamic modulus(E*)of hot mix asphalt concrete.Using a substantial dataset from NCHRP Report-547,the model was trained and rigorously tested.Performance metrics,specifically RMSE,MAE,and R2,were employed to assess the model's predictive accuracy,robustness,and generalisability.When benchmarked against well-established models like support vector machines(SVM)and gaussian process regression(GPR),the AHA-boosted model demonstrated enhanced performance.It achieved R2 values of 0.997 in training and 0.974 in testing,using the traditional Witczak NCHRP 1-40D model inputs.Incorporating features such as test temperature,frequency,and asphalt content led to a 1.23%increase in the test R2,signifying an improvement in the model's accuracy.The study also explored feature importance and sensitivity through SHAP and permutation importance plots,highlighting binder complex modulus|G*|as a key predictor.Although the AHA-boosted model shows promise,a slight decrease in R2 from training to testing indicates a need for further validation.Overall,this study confirms the AHA-boosted model as a highly accurate and robust tool for predicting the dynamic modulus of hot mix asphalt concrete,making it a valuable asset for pavement engineering.
文摘Introduction: Endoscopic internal urethrotomy (EIU) is a method for stricture opening using transurethral incision by direct visualisation of the urethral channel, resulting in a widening of the urinary canal with the aim of improving the quality of bladder emptying. The aim of the study was to evaluate the indication and results of EIU in the treatment of stenosis of the male urethra in the Urology-Andrology Department of Kara Teaching Hospital. Methodology: This was a cross-sectional descriptive study with retrospective data collection in the Urology-Andrology department of Kara Teaching Hospital. It involved 21 records of patients with urethral stenosis treated by endoscopic internal urethrotomy (EIU) in the said department during the period from January 2021 to September 2023. The following variables were evaluated: age, circumstance of discovery, site, length, number, etiology of the urethral stenosis and evolution of the patients. Results: The mean age of the patients was 59.2 ± 11.7 years. Infectious etiology of stenosis was predominant with 10 patients (47.6%) followed by trauma with 5 cases (23.8%). The bulbar urethra was the most frequently observed site, with 11 cases (52.4%). The length was mostly less than 2 cm in 12 patients (57.1%). Stenosis was unique in 14 patients (66.7%). The mean postoperative follow-up time was 3.2 months. The result was immediately better in 11 patients (52.4%) and it was poor in 8 patients (38.1%) who required maintenance dilation sessions.
文摘The interest of this conference is agricultural, environmental, bioenergetics, and sanitary. In that context, domestic, agricultural and industrial environments produce organic waste, which needs to be collected, selected, stored and recycled properly in order to avoid environmental pollution and promote agriculture. The green Industry proposed involves the conversion of natural, non-toxic organic waste in order to efficiently produce organic fertilizers for agriculture. These types of fertilizers from biological origin are suitable because they are not toxic for human and the environment. Enzymatic reactions described in this presentation concern mainly the hydrolysis of proteins, sugars and lipids, the acidification of intermediate products from hydrolysis, the formation of acetate, and the production of methane. In other words, this review is timely as it discusses for the chemical behavior or the reactivity of different functional groups to better understand the enzymatic catalysis in the transformations of residual proteins, carbohydrates, and lipids to generate biomethane and fertilizers. In the same perspective, this review is to enrich the documentation related to organic reactions catalyzed by enzymes, which occur in the anaerobic degradation of residual organic substances, with emphasis on the structures of organic compounds and reaction mechanisms. This will allow understanding the displacement of the electrons of a reactive entity rich in electrons to another reactive entity that is poor in electrons to form new bonds in products.
文摘This study focuses on the determination of physical and mechanical characteristics based on in vitro tests, by using field samples for the Kampemba urban area in the city of Lubumbashi. At the end of this study, we identified the soils according to their parameters, and established the geotechnical classification by determining their bearing capacity by the group index method using from the identification tests carried out. By using the AASHTO classification method (American Association for State Highway Transportation Official), the results obtained after our studies revealed five classes of soil: A-2, A-4, A-5, A-6, A-7 in a general way, and particularly eight subgroups of soil: A-2-4, A-2-6, A-2-7, A-4, A-5, A-6, A-7-5 and A-7-6 for the concerned area. The latter has given statistical analysis and deep learning based on multi-layer perceptron, the global values of the physical parameters. It’s about: 31.77% ± 1.05% for the limit of liquidity;18.71% ± 0.76% for the plastic limit;13.06% ± 0.79% for the plasticity index;83.00% ± 3.33% for passing of 2 mm sieve;76.22% ± 3.2% for passing of 400 μm sieve;89.07% ± 2.99% for passing of 4.75 mm sieve;70.62% ± 2.39% passing of 80 μm sieve;1.66 ± 0.61 for the consistency index;<span style="white-space:nowrap;">−</span>0.67 ± 0.62 for the liquidity index and 8 ± 1 for the group index.
文摘Pharmaceutical counterfeiting is a health scourge responsible for several cases of morbidity and mortality. Counterfeit medicines cause therapeutic failure, emergence of resistance in the treatment of infections. This study was conducted in order to identify counterfeit and authentic medicines in circulation in Lubumbashi. The study included artemether and artesunate for oral administration. A careful visual inspection of medicine, investigation of authenticity of pharmaceutical products from manufacturers and pharmaceutical regulatory authorities and determination of content were used as study parameters. 52 samples: 37 artemether and 15 of artésunate were collected. 7 samples (13%) have proven to be counterfeit. Artemether was the most counterfeit (71%) and 29% for artesunate. 6 (12%) samples were substandard according to the international pharmacopoeia in terms of content of active ingredient. Sixty-seven percent of non-compliance concerned counterfeit medicines. The proportion of non-compliance is highest among counterfeit medicines (71.43% vs 2.22%;p = 0.000004). It is obvious that strengthening the capacity of the drug regulatory authority of the DRC reduces the influx of counterfeit drug and substandard.
基金supported by the National Natural Science Foundation of China(22008221)Startup Research Fund of Zhengzhou University(32211716)+3 种基金Key Scientific Research Projects of Colleges and Universities in Henan Province(21A530005)Guangdong Basic and Applied Basic Research Foundation(2021A1515110789)Hunan Provincial Natural Science Foundation of China(2022JJ40431)Zhengzhou Collaborative Innovation Major Project。
文摘Spent cathode carbon(SCC)from aluminum electrolysis is a potential graphite resource.However,full use of the SCC remains a challenge,since it contains many hazardous substances(e.g.,fluoride salts,cyanides),encapsulated within the thick carbon layers and thus posing serious environmental concerns.This work presents a chemical oxidative exfoliation route to achieve the recycling of SCC and the decontaminated SCC with high-valued graphene oxide(GO)-like carbon structures(SCC-GO)is applied as an excellent adsorbent for organic pollutants.Specifically,after the oxidative exfoliation,the embedded hazardous constituents are fully exposed,facilitating their subsequent removal by aqueous leaching.Moreover,benefiting from the enhanced specific surface areas along with abundant O-containing functional groups,the as-produced SCC-GO,shows an adsorption capacity as high as 347 mg·g^(-1)when considering methylene blue as a pollutant model,which exceeds most of the recently reported carbon-based adsorbents.Our study provides a feasible solution for the efficient recycling of hazardous carbonaceous wastes.
文摘Trace metal levels of groundwater in Lubumbashi,Kampemba and Kamalondo communes of Lubumbashi city were assessed from October 2016 to February 2017.Two hundred forty water samples collected from twenty-two spade-sunk wells and twelve drilled wells in these three communes of Lubumbashi city were analyzed for their metal contents using ICP-SF-MS(Inductively Coupled Plasma-Sector Field Mass Spectrometry).Twenty trace elements including strontium,molybdenum,cadmium,cesium,barium,tungsten,thallium,lead,bismuth,uranium,aluminum,vanadium,chromium,manganese,iron,cobalt,nickel,copper,zinc and arsenic were recorded at varying concentrations in all the water samples and were compared with the WHO(World Health Organization),US EPA(Environmental Protection Agency)and EU(European Union)drinking water MCLs(Maximum Concentration Limits)for cadmium,barium,thallium,lead,uranium,aluminum,chromium,manganese,iron,nickel,copper,zinc and arsenic.Mean cadmium,lead,aluminum,manganese,iron,nickel,zinc and arsenic levels respectively exceeded the WHO,US EPA and EU drinking water MCLs in 6.66%,3.38%,26.67%,5.02%,30.03%,3.38%,1.64% and 5.02% of the samples with the highest mean levels of 116.89μg/L for cadmium,38.162μg/L for lead,2,712.5μg/L for aluminum,1,242.68μg/L for manganese,17,325.98μg/L for iron,64.647μg/L for nickel,9,900.72μg/L for zinc and 65.458μg/L for arsenic.Mean water pH values ranged from 4.7 to 11.1 with 19.17% of the groundwater samples having mean pH values outside the WHO drinking water pH optimum range values of 6.5-8.5,including 5.02% of the water samples which were acidic(mean pH values ranging from 4.7 to 6.4)and 14.15% which were alkaline(mean pH values ranging from 8.6 to 11.1).With such physicochemical and trace metal contamination status of groundwater in the three communes of Lubumbashi city,there is a high risk to the health of people who use that water to meet their drinking water needs.
文摘<strong>Introduction:</strong> Geohelminths are infections due to various species of parasitic worms transmitted by eggs present in human excreta which contaminate the soil where sanitation is poor. The objective of this study was to analyse the determinants and knowledge on geo-helminthiasis among inmates and care providers in the Kassapa prison environment in Lubumbashi in the Demographic Republic of Congo. <strong>Methods:</strong> This is a cross-sectional descriptive study which was conducted from September 21 to October 15, 2020 in Kassapa prison in Demographic Republic of Congo. Estimates of the prevalence and general characteristics of geo-helminthiasis in prisoners were calculated by descriptive analyses. The analysis of determinants was performed based on a binary logistic regression. <strong>Results:</strong> With regard to the quantitative section, the study used a sample size of 1083 while a sample size of six was considered for the qualitative section. The annual prevalence of geo-helminthiasis was 10.2%, 4.8% and 2.9% respectively for 2017, 2018 and 2019. It was found that the general prevalence of geo-helminthiases was 17.9%. The age group above 39 years constitutes the modal class with 29.4%, the least affected age group being that of minors with 6.3%. The association is statistically significant between sex, treatment, prison residence and year. Thus, taking gender into account, women are by 2.3 (OR = 2.3, 95% CI [1.3%;4.8%], p value < 0.05) more likely to be at risk of suffering from geo-helminthiasis than men, and mebendazole is by 2.1 a better treatment of geo-helminthiasis than albendazole (OR = 2.1, 95% CI [1.1%;4.6%], p-value < 0.05). Transmission routes of geo-helminthiasis are relatively well known among these actors who have often reported eating dirty food, walking barefoot, and drinking dirty water. <strong>Conclusion:</strong> This descriptive cross-sectional study rounds off by pointing to poor hygiene, insufficient health education and a low socio-economic level exposing inmates to the risk of contracting geo-helminthiasis, particularly as prisoners in Kassapa live in a difficult situation and are therefore very vulnerable.
文摘<strong>Objective:</strong> <span><span><span style="font-family:""><span style="font-family:Verdana;">To determine the psychosocial problems, social acceptance and the impact of the costs of parents whose child has cancer. </span><b><span style="font-family:Verdana;">Method: </span></b><span style="font-family:Verdana;">We carried out a descriptive cross-sectional study over two-year periods (from January 3, 2018 to March 31, 2020) in the pediatric oncology unit of clinics at the University of Lubumbashi, in DR Congo. </span><b><span style="font-family:Verdana;">Results:</span></b><span style="font-family:Verdana;"> 129 parents of children with cancer in the pediatric oncology unit were included in our study. Most children with cancer (53%) were accompanied by their mothers who had a low level of education (53.0%). Emotional shock was the most observed reaction (68%) to the announcement of the disease (cancer). Retinoblastoma has had a significant economic impact on families without medical coverage. Only 38% received psychological support from parents. Sadness was the most common feeling (77%) of households. Support workers consider their relationship with the medical profession acceptable in 67% and difficult in 11%. The majority of parents (78%) felt that the time to provide medical care was longer than expected. </span><b><span style="font-family:Verdana;">Conclusion: </span></b><span style="font-family:Verdana;">Parents of children with cancer had different feelings and reactions. This observation may be useful for the development of a health policy, in particular that of pediatric cancer in DR Congo.</span></span></span></span>
文摘<strong>Introduction:</strong> Noise, an undesirable sound which is found in all areas of occupational activity, is still a matter of concern given the damage it causes. Various machines and tools, from simple to sophisticated ones, produce several types of noise in the workplace. The purpose of this study was to assess the current status of occupational hearing loss among informal sector welders in the city of Lubumbashi, in the Democratic Republic of Congo. <strong>Methods: </strong>This was a descriptive cross-sectional study which was conducted among 122 informal sector welders over a period of five months. The study used an anonymous questionnaire on noise exposure in the workplace and collected audio-metric data of welders. The survey collected data on welders who had a minimal three-year duration of employment without the morbidity associated with the Ear Nose Throat (ENT) region. Socio-professional data (age, duration of employment, sex, education), noise exposure, awareness of hazards and audiometric data were taken into account. <strong>Results:</strong> 122 questionnaires were completed by male subjects, or 100% (n = 122). The mean age of welders was 36.37 ± 11.91 years with extremes being 20 and 63 years. The mean duration of employment was 11.51 ± 9.6 years with extremes being 3 and 44 years. Audiometric data have shown 37.96% (n = 41) of occupational hearing loss. Three degrees of hearing loss were recorded, notably mild hearing loss standing at 80.49% (n = 33);moderate and severe hearing loss standing at 2.44% (n = 1). Ninety-six percent (n = 117) of welders reported not using personal protective equipment (PPE) and 1% (n = 111) were aware of the hazard associated with noise exposure in the workplace. A correlation was found between welders with an advanced age (p < 0.001;RP = 3.66 (2.16 - 6.22)) and hearing loss, and between the duration of employment and hearing loss (p < 0.001;RP = 6.48 (3.32 - 12.65)). <strong>Conclusion: </strong>In the study area, occupational hearing loss among welders is a relevant fact. Three degrees of hearing loss were identified. Most of those suffering from it have developed a mild type of hearing loss whose continued development can be stopped. Despite the fact that welders are aware of the hazards associated with noise exposure in the workplace, they hardly protect themselves. Lack of a culture of prevention and poor enforcement of the existing laws could account for such a situation. There seems to be a crucial need to put in place a program for protecting the welders’ auditory organs in the workplace.
文摘Bushmeat is frequently consumed in households in the city of Lubumbashi in the Democratic Republic of Congo.Several studies in Africa show that this food is regularly consumed by rural and urban populations.This consumption is motivated by several reasons.These have never been elucidated in the city of Lubumbashi.This study aims to highlight the sociocultural aspects that justify the consumption of bushmeat in order to consider its sustainability.A survey was conducted among 1,400 households in the municipalities of the city.A questionnaire helped collect the information that was presented as a percentage.This information shows that 86.6%of the population consume monthly(41.3%)of bushmeat.This consumption is based on taste(51.7%).On the other hand,religious beliefs(29.2%)prevent this consumption.The order of the artiodactylsis is the most affected(74.2%).The recognition of the species consumed comes from the information provided by the sellers(58.5%).Bushmeat comes from the district of Haut-Katanga(35.2%).It is sold in the main markets of the city of Lubumbashi(67.9%).Bush meat is becoming an exhaustible natural resource,mechanisms and alternatives will need to be put in place to enable the sustainable conservation of wild animal species.
文摘Introduction: Rabies, a neglected disease, could be grossly underreported in the DRC;in the absence of post-exposure prophylaxis, the WHO estimates that this disease would cause 327,000 deaths per year in Africa and Asia. The objective of this study is to determine the epidemiological profile of this zoonosis in order to encourage decision-makers to develop national strategies for its elimination. Materials and Methods: We conducted a cross-sectional descriptive study. Data collection was done retrospectively and in total6 420 victims of bites received during the period between January 2005 and December 2015 at the anti-rabies center in Lubumbashi were included in this work. Excel 13 software and Epi info 3.3.4 were used for data analysis and interpretation. Results: People over the age of 15 are the main victims of canine bites (62.1%), more than half of the victims are male (55.9%);dogs represent the majority of biting animals (96.4%) of which around 3/4 are unvaccinated (71.37%). Two municipalities are more affected: Lubumbashi (prevalence 83.35/100,000 and Kampemba (Prevalence 51.74/100,000). LBite peaks were observed from July to October (p = 0.01). For the 34 people seen with clinical signs of rabies encephalitis (confirmed case of rabies), the case fatality rate was 100%. Conclusion: Rabies is a major problem in Lubumbashi but its extent is different depending on the municipality. The dog is the main biting animal and the vaccination coverage of dogs remains very low. Access to rabies vaccine for bite victims is difficult. Its elimination remains possible through the implementation of an extensive canine vaccination program, the awareness of owners and the large-scale provision of post-exposure prophylaxis.
文摘Introduction: Public hospitals in the DRC are of significant disrepair, while there is a strong link between the failure of hospital hygiene and the incidence of nosocomial infections. We have conducted a study with the objective of evaluating the structural-functional conditions of hospital hygiene maternity wards of public hospitals in Lubumbashi. Methodology: It was a descriptive cross-sectional study and structural-functionalist whose population consisted of nurses responsible for 7 of 12 maternity hospitals which were selected based on the inclusion criteria. The observation with an observation guide and maintenance using a questionnaire we used to collect data. Results: The results showed that hospital hygiene conditions in maternity wards of public hospitals in Lubumbashi are not good because almost all maternity services and surgery are not always water in the taps (14.3%). The bins were a means for care units, no coding system exists to distinguish the type of waste. The medical waste are mixed and the other waste are burned in the open or in makeshift incinerator with other types of waste. Conclusion: These maternity wards have poor hygiene, staff responsible for this sector did not follow any training in this area. There is need to regulate the sector and train them.
文摘Nanoparticles have distinct properties that make them potentially valuable in a variety of industries.As a result,emerging approaches for the manufacture of nanoparticles are gaining a lot of scientific interest.The biological pathway of nanoparticle synthesis has been suggested as an effective,affordable,and environmentally safe method.Synthesis of nanoparticles through physical and chemical processes uses unsafe materials,expensive equipment and adversely affects the environment.As a result,in order to support the increased utilization of nanoparticles across many sectors,nanotechnology research activities have shifted toward environmentally safe and cost-effective techniques that outperform chemical and/or biological procedures.The use of organisms to produce metal nanoparticles is among the most frequently discussed methods.Plants appear to be the best candidates among these organisms for large-scale nanoparticle biosynthesis.Medicinal plants have been employed as reducing agents and NP stabilizers to minimize the toxicity of NPs in both the environment and the human body.Furthermore,the presence of certain functional components in plant extracts may be extremely useful and effective for the human body.Polyphenol,for example,which may have antioxidant properties,might intercept free radicals before they interact with other biomolecules and cause considerable damage.The current article analyzes the most recent developments and improvements in the green synthesis of metal nanoparticles by different plants and the use of these nanoparticles for various biomedical applications and hopes to provide insights into this exciting research frontier.
文摘The objective of the study was to identify the failure factors of community interventions in terms of HIV activities in the province of Haut-Katanga during the year 2016. Materials and Methods: The study was phenomenological of the factors, carried out in Haut Katanga. All health facilities (FOSAs) having integrated the prevention of transmission of HIV infection from mother to child (PMTCT) were included in the study. The collection was carried out through individual semi-structured interviews with PMTCT focal points, mentor mothers and people living with HIV (PLWHA) cared for in some of these health facilities (FOSAs). The number of participants was determined by the saturation of responses. Nvivo v.11 software was used for the analyses. The data of each woman was handled confidentially. The authorization of the ethics committee of the University of Kinshasa ESP/CE091/2015, the free and written consent, was obtained before collecting the information. Results: It was observed the socio-cultural factors of success and failure of the interventions: the social fear generated by contradictory messages in the sensitization of the community;the lack of an obvious strategy for the involvement of the partner;the weak coordination of community care activities between the central office of the health zone;the FOSA and the community worker: low interest in community care evidenced by weak accountability of FOSAs, community and program providers in this regard;that relates to community activities;coordination of care between care units;overload of the staff in charge of activities within the health structure and their low motivation;the low communication time devoted to people living with HIV in the FOSAs. Conclusion: The study shows that interventions that can improve the quality and outcomes of prevention of mother-to-child transmission of HIV (PMTCT) services can be directly linked to the program itself, as well as come from another or the community, which generally remains the weak link in which efforts are even less noticeable, at least as far as PMTCT is concerned. Integrating care data for the mother-child couple improve the continuum of services between the different care units as well as the quality of data management.
基金This study was carried out in the framework of the research project entitled“Assessing and Mapping the Environmental and Health Impacts of Abandoned and Ongoing Mining Activities in Lubumbashi and Its Neighborhood,Democratic Republic of Congo”with UNESCO-Sida Project funds(Contract No.4500309530).
文摘Arsenic,barium,bismuth,cadmium,cesium,chromium,cobalt,copper,iron,lead,manganese,molybdenum,nickel,strontium,thallium,tungsten,uranium,vanadium,and zinc concentrations were investigated in forty-two groundwater samples,twenty-four surface water and six surface sediment samples in Kinsevere industrial zone and its surroundings in February and march 2017,January,February and March 2018 to evaluate the potential human health risk.Chemical analyses were carried out by using ICP-SF-MS(Inductively Coupled Plasma-Sector Field Mass Spectrometry,Thermo Scientific Element II).The trace metals were detected at various concentrations in all the analyzed samples.Pb,Mn and Fe concentrations exceeded the European Union acceptable maximum limits for water intended for human consumption in 4.76%,28.57%and 61.90%of the groundwater samples,respectively and in 0%,50%and 100%of the surface water samples,respectively.As,Cr,Cu and Ni concentrations exceeded the recommended lower sediment quality guideline values in 33.33%,50%,83.33%and 83.33%of the surface sediment samples,respectively.All those elevated trace metal concentrations in the groundwater,surface water and sediments represent a risk for the health of local population as well as for aquatic organisms.
文摘Environmental change is characterized as an alteration in the environment caused primarily by human activities and ecological processes that are natural. Given the fact that the southern part of the province of Haut-Katanga in the Democratic Republic of the Congo (DRC) is part of the African Copperbelt and has been a region of intense mining for decades, humans have affected the physical environment in various ways: such as overpopulation, suburbanization, wastage, deforestation. It is therefore important to track and control the changes in the area’s mining activities. This study aimed to analyze these changes using remote sensing techniques. Landsat satellite images from 2002 and 2022 were processed and classified to quantify changes in built-up area, agricultural land, and vegetation cover over the 20-year period. The classification results revealed sizable differences between the two time points, indicating considerable expansion of built-up land and declines in agricultural land and vegetation cover from 2002 to 2022 in Likasi. These findings provide evidence that urban growth has transformed the landscape in Likasi, likely at the expense of farmland and ecosystems. Further analysis of the remote sensing data could quantify the changes and model future trends to support sustainable land use planning. The land cover and land use analysis were performed with the assistance of the ERDAS 16.6.13 software by mapping LANDSAT data from two different years 2002 and 2022.
文摘The Mokama granites are located in the Kibara belt (KIB) and hosts tin oxide group minerals (TOGM: Sn-W), and sulfide group minerals (SGM: Cu-Zn-Fe-As). The essential of Cu mineralization (non-economic deposit) is disseminated inside the rock and consists of minerals (Raman, EPMA and metallographic microscopy) including chalcopyrite and bornite that are replaced by chalcocite and covellite, and the last also replaced later by malachite. The chemistry (XRF, LA-ICP-MS) of these peraluminous S-type leucogranites show SiO<sub>2</sub> (71 wt% - 79 wt%), ASI (1.4 - 3.1 molar), and are enriched in Rb (681 - 1000 ppm), Ta (12–151 ppm), Sn (43 - 142 ppm), Cu (10 - 4300 ppm), Zn (60 - 740 ppm), U (2.2 - 20.7 ppm) while depleted in Zr (20 - 31 ppm), Sr (20 - 69 ppm), Hf (1.3 - 2.0 ppm), Th (2.2 - 18.9 ppm), W (9 - 113 ppm), Pb (5 - 50 ppm), Ge (5 - 10 ppm), Cs (21 - 53 ppm) and Bi (0.6 - 17.4 ppm) and low ratios of (La/Yb) N, (Gd/Yb) N, (La/Sm) N). Fluid inclusion assemblages (FIAs) hosted in quartz in the Mokama granites show ranges of salinities of 4 - 23 wt% (NaCl equivalent) and homogenization temperatures (Th) of 190°C - 550°C. A boiling assemblage in the granite suggests a fluid phase separation occurred at about 380 - 610 bars, and this corresponds to apparent paleodepths of approximately 1 - 2 km (lithostatic model) or 3 - 5 km (hydrostatic model). FIAs hosted in TOGM such as cassiterite (salinities of 2 wt% - 10 wt% and Th of 220°C - 340°C) helped set up the possible temperature limit of SGM (Cu sulfide) precipitations that are estimated below 200°C.