Oil production in unconsolidated reservoirs such as sandstone can be really challenging because of solids coming from the formation. In order to solve problems caused by produced solids, frac-packing is one of the methods used. It aims to maintain or increase production and control produced solids. This research focuses on the hydraulic fracturing part of that method. A numerical model is created using CMG-2015 with data from a given field to analyze the effects of some factors on oil production. Two cases are considered in this research, the first one is a one-layer case and the second one is a two layers case. Water is injected into the reservoirs in both cases. The results reveal that formation damage by its degree (Ks/K) and size can significantly decrease oil production and fracturing treatment can help recover the oil production to almost the initial value. After bypassing the damaged area, keeping increasing fracture half-length and conductivity is not important because there is no significant effect on the production. The results also show that for double layers case, the best way to increase oil production is to fracture the low permeability layer and maintain or leave the formation damage that will naturally happen.

This study is carried out in the city of Kenge, chief town of the province of Kwango in the Democratic Republic of Congo with the aim of analyzing the mechanisms by which female entrepreneurship in the informal sector focused on fortune restaurants «Malewa» contributes to the survival of a pauperized population. In total, 20 makeshift restaurants according to the criteria for provision of a family workforce or non-working without contract with a monthly remuneration not exceeding the equivalent of $ 30, the absence of the legal documents required to exercise trade and the non-use of a regular accounting organization have been identified. The results obtained have revealed many unknown realities in the sector. The management mode of these units, the quality of jobs created in the sector, the quality of the dishes presented to the clienteles and the craze that is observed leaves to be desired.

The G5 Sahel, a region marked by its rich history and vast potential, confronts a myriad of socio-economic challenges and opportunities. This article delves into the intricate economic landscapes of the G5 nations, highlighting the pivotal role of resource-driven conflicts, with a focus on the significance of uranium in Niger’s affairs. As the region grapples with external economic dynamics, the enduring economic influence of colonial powers, notably France, is evident. The burgeoning economic engagements of China in the Sahel further complicate the geopolitical canvas. However, the region’s resilience shines through indigenous solutions, emphasizing the importance of traditional economic systems. Examples such as Mali’s ‘Tontines’ and women-led cooperatives in Niger underscore the potential of grassroots initiatives in fostering stability. Furthermore, the prospects of regional economic collaboration among the G5 Sahel nations present a pathway to harnessing collective growth and reducing tensions. The article advocates for a balanced approach: leveraging external partnerships while prioritizing local solutions and regional collaborations, as the G5 Sahel charts its course towards a sustainable future.

This research work addresses the topic of the success of information systems (IS) as a multidimensional concept that requires evaluation based on four characteristics. These are the unit of analysis, the object of analysis, the timing of evaluation, and the type of IS evaluator. A literature review is presented, focusing on the various dimensions of IS success, whether tangible or intangible. These dimensions include IS quality, its usage, user satisfaction, customer satisfaction, organizational context, and performance. The objective of this article lies in highlighting the interdependent characteristics and dimensions that must be considered to measure IS success. This will enable the selection of the most appropriate criteria based on the context and the research problem.

Artisanal gold mining, which is booming in the Seke-Banza Territory, has adverse effects on the agricultural production of the main speculations, in particular cassava, maize, groundnuts, paddy rice and beans. This article analyzes, from a field survey and bibliographic and documentary research, the effects of artisanal gold mining on agricultural production in Seke-Banza. The results obtained indicate that artisanal gold mining has favored the reduction of food production areas, the flight of agricultural labor to the benefit of this new conquest for gold, the reduction of agricultural work time and the agricultural land degradation. This results in a decrease in agricultural production due to the deterioration of factors of production. The mitigation of these effects requires the implementation of certain actions proposed by the gold panning actors met. These actions are summarized by good governance (laws that protect highly productive agricultural areas, commonly called «agricultural production basin») the revaluation of agriculture (rehabilitation of the National Agricultural Extension Service, rehabilitation of agricultural service roads and others related extension support services) and supervision of artisanal gold miners (rehabilitation of the Assistance and Supervision Service for Small-Scale Mining SAEMAPE).

As a practitioner of Non-Destructive Testing, the control of the weld is one of the most delicate exercises and of great importance considering that, the pooling of two materials of different chemical compositions, by the contribution of another material (formerly) is a demanding operation. Mastering the practice of welding implies knowledge of certain parameters which include welding processes, qualification and certification of welding practitioner’s method and the various related standards. IN Lubumbashi, town of Haut-Katanga, several welding points (stations) are installed, some along major arteries.

Spirulina is a food supplement rich in micronutrients and vitamins. It is called «the ideal food for humanity» and the World Health Organization has considered it a «super food» and the best food for the future due to its high nutritional value. This study aimed to evaluate the levels of α-tocopherol in 20 samples of spirulina before and after sun drying. This was an analytical study aimed at determining the levels of α-tocopherol in fresh and after dried spirulina using high performance liquid chromatography (HPLC). The average α-tocopherol content of fresh spirulina was 3.48 mg/100 g. After drying, the average α-tocopherol content was 4.37 mg/100 g, an increase in α-tocopherol of 25%. Drying and packaging spirulina remains the only means of wide commercial distribution. Nutritional losses were not observed after drying the spirulina. However, it is advisable to consume spirulina fresh or just after drying because prolonged storage could destroy some active ingredients necessary for good human nutrition.

Objective: Evaluate the perception of cement workers in Guinea on their physical working conditions. Materials and methods: This was a descriptive cross-sectional survey of 112 workers occupying open offices (5 to 10m2), lasting 6 months from August 1, 2021 to January 31, 2022. The GABO questionnaire (Acoustic Discomfort in an Open Office) was used. Results: 112 workers responded to the survey. The male gender was the most represented with an M/F sex ratio of 10.2. Among respondents, 59% shared the workspace with 2 to 6 people; 8% worked alone. Nearly half were moderately satisfied with their workspace (average of 2.88 out of 5). The perception of the comfort of their workspace was good (average 3.17 out of 5). 68.75% felt that the noise in their workspace was high and annoying or even very annoying. The highest source of noise 68.75% and the most annoying 66.97% was the operation of machines. 78.43% felt moderately or even very tired at the end of the day, among them 70.50% had an average recovery capacity of two working days. Conclusion: The results of the study show that working conditions at Cement of Guinea are unsatisfactory. This study should therefore be extended to other companies to be able to improve working conditions in order to prevent the long-term consequences of the various factors that influence the working environment.

Objective: Our study aimed to determine the frequency of Kidney Disease among artisanal gold miners in the urban commune of Siguiri. Materials and methods: This was a descriptive cross-sectional study lasting six (6) months from July 11, 2020 to January 11, 2021. Our study focused on all artisanal gold miners of all ages, regardless of gender. nor from a country presenting an anomaly of the urinary sediment (hematuria, leukocyturia) and/or proteinuria, and/or a GFR ≤ 60ml/min. Results: During our study, of the 250 miners who were screened, 26 presented with chronic kidney disease, a frequency of 10% against 224 non-sick, i.e. a frequency of 90%. The median age of the sick miners was 35.50 years with age extremes of 15 to 80 years; the male sex was the most represented with a sex ratio M/F of 1.88. The main risk factors were nephrotoxic drugs (51.85%), urinary tract infections (27.63%), hypertension (22.22%), and obesity (14.81%). The clinical signs were dominated by headaches (76.80%), physical asthenia (52.80%). The majority of artisanal miners had a creatinine clearance ≥ 90ml/min, i.e. 69.23% according to the MDRD formula. Conclusion: early detection, appropriate care and a healthy lifestyle can reduce the occurrence of complications and the appearance of CKD in the final stage.

Objective: Given the importance in Guinea of ​​the informal economy with an estimated share of 43% of GDP and 96% of jobs. The profession of welder, like other professions in the informal sector, is not exercised without risk. Our study aimed to assess the occupational risks associated with welding in the workshops of the municipality of Matoto, Conakry. Method: This was a prospective descriptive study lasting one year from January 5, 2021 to December 31, 2021. Welders from the informal professional sector in the welding workshops of the municipality of Matoto, who were present and who agreed to participate in the study, were included. The data were analyzed using the Epi-info statistical software version 7.2.2.6. Result: We registered 212 male welders. The average age of the welders was 28.33 ± 12.46 years. The age group from 15 to 29 years old was the most represented at 59.3%. Common damage was arc flash 88.2%; followed by skin burns 84.4%, hand cuts/wounds 78.3. Only 0.5% of workshops had a fire extinguisher, 3.3% handling accessories. The occurrence of arc flash was significantly associated with exposure to UV/IR from the welding arc (p = 0.0000). Foreign body in the eye was associated with full-time work (p = 0.0024). Conclusion: The welder’s experienced significant eye and skin morbidity accentuated by the non-use of collective and individual protective measures. Factors such as level of education, income, seniority and full-time work were significantly associated with self-reported injuries and PPE use among welders (p ˂ 0.05).

Each corporate event of interest could be analyzed through several approaches. In the recent finance literature, there are common methods emanating from two notorious approaches, that are: the CAR and BHAR methods belonging to the event study approach, and those that fall into the second approach of calendar time, namely the CTAR, and the asset pricing models; starting with the Fama and French’s three-factor model to the refined multi-factor models. The Initial Public Offering (IPO) is a corporate event that consists of the operation to open up the capital to investors, it is a strategic decision where companies make that step toward the capital market, especially the stock exchange market, and go from private to public. This event can be analyzed and studied through the approaches named above, based on the computation of abnormal returns around the IPO event, which, in turn, could be calculated through the statistical models (Constant Mean Return Model, Adjusted Market Return, Market Model) and economic ones (Capital Asset Pricing Model (CAPM), Arbitrage Pricing Theory (APT)). Both approaches (the event study, and the calendar time) have been and still are under criticism, according to many researchers the outcomes and findings depend on the methodology used to evaluate the performance of IPOs from the first step of defining abnormal returns, to the application of methods assembling them, till the test of the null hypothesis. The following paper is a kind of literature review where we tried to assemble a number of theoretical and empirical papers and works containing the pieces of information we need to aid in answering this question of evaluating the IPO’s performance through different methods and arbitrating between them.

This research consists in understanding the process through which the entrepreneur arrives to the entrepreneurial rebound, which means rebound from failure and launching new business. Eventually, understanding entrepreneur’s resilience processus includes identifying the dimensions that constitute it. The results of this study emphasize that grief is a common and inherent phase, that entrepreneurs must overcome in order to accept their failure. Acceptance allows them to restore their mental state so that they can make sense of their experience and learn from it, the thing that helps them to reconstruct. And therefore, take action and engage in a new project. The support of the entrepreneur’s environment is essential, according to the results found. It is important for the entrepreneur’s resilience and a rebound condition. The results on this point revealed characteristics specific to the Moroccan context. In this sense, the entrepreneur’s environment is limited to the close environment (family, friends, etc.), the quality of professional social ties, the support of the State and the role of culture. We have concluded that entrepreneur’s resilience is a socio-emotional process that requires analysis at two levels, inter-individual and intra-individual, and that the entrepreneur’s context has a significant impact on his or her ability to bounce back from failure.