MBUYI KALUBI Charles1*, MUSESA LANDA Alain1

On Affine transformations in continuous and in discrete spaces

A quasi-affine application, being the integer part of a rational affine application, is the discretized form of an affine application. This article is dedicated to the study of conservation of same properties of affine applications (Preservation of barycenter, preservation of distance, existence of a fixed point) by quasi-affine applications. The quasi-affine applications studied are discrete translations, discrete homotheties as well as discrete rotations. Télécharger l'article

DIANGITUKULU NDIMBA Samuel1*, MUSESA LANDA Alain1.

Distributions associated to a foliation and Lie-Rinehart algebra.

In this paper we determine a Lie-Rinehart algebra structure on the submodule, 𝔛(F), associated to the 𝑇Fdistribution, we define the Lie-Rinehart algebra structure concept on the foliation in leaf geometry and then we deduce that any distribution associated to a foliation F is completely integrable. Téléchargé l'article

WADI TUSAMBILA Valéry *1, CANBULUT Fazıl2, UYSAL Ünal3.

In axial piston pumps, increasing the temperature of lubricating oil causes undesirable conditions such as degradation of the thermophysical properties of the oil. Among these properties, the viscosity of lubricating oil varies proportionally with the temperature of the oil. Thus, beyond a definite temperature value, the oil no longer fulfills its lubrication function. The consequence is a mixed friction causing an overheating of the slipper, the deformation of the surfaces and finally the wear of the pump. However, temperature of slippers directly affects the lubricating oil temperature. In order to improve energy efficiency and lifetime of piston pump, the present study aims to investigate the influence of operating parameters on the temperature of hydrostatic
slipper bearing using a designed experimental set-up. Three different types of slippers were made in bid to observe the effect of slipper geometry on the temperature. This study outcomes show an increasing of the temperature of the slipper with increasing of supply pressure. It has also been found that an increase in the rotation speed induces an increase in the temperature of the slipper. Compared to the slipper- I, with diameter ration De/Di =1.422 and which reaches a temperature of 79°C under a pressure of 30 bar at rotation speed of 300 rpm, the slippers III and II with diameter ratios of 1.784 and 1.69 respectively presented geometries which better minimize the temperature increase of the slippers at 43°C and 47°C respectively under the same conditions. Téléchargé l'article

MUKONKOLE MUKONKOLE Patrick1*, ILITO LOFONGO Daddy Patrick1, KANDA NKULA Valentin1, 2, MUANZA KANT Patrick1, MUILU MAYALA Daudet1, PINGANAY SABUA1.

Preliminary metallogenic study of the green rocks of Gangila in the West Congo Belt (WCB) in Democratic Republic of Congo

The green rocks of Gangila are located along the Mvuzi River in the territory of Seke-Banza. The collected samples were subjected to petrographic studies (thin sections and polished sections) and chemical analyzes to determine the genetic environment of these rocks as well as the origin of the brines having traveled these metamorphites. The results of the chemical analyzes of the major and trace elements carried out on these rock samples and on the quartz vein allowed us, with the help of DTI (Ternary Diagram of Intiomale) to conclude that these rocks originated in a "Distensive regime" and the brines circulating in these Gangila metamorphites have a "mixed origin" at a temperature of 347°C which is characteristic of the "pleothermal stage" according to the geothermometric scale Ca-Ti. Such a temperature would be related to oceanic opening and mobilizing Kuroko type fluids. The so-called mixed solutions result from the mixing of supergene fluids with hypogenous fluids from subalkaline granitoids. Metalliferous minerals are disseminated on these metamorphites and offer no preference for any type of rock. Disseminations of chalcopyrite observed under a microscope on the polished sections of these green rocks show that chalcopyrite mineralization is ubiquitous and results from a mixture of circulating solutions in the metamorphites. These metals should therefore come from the metamorphites themselves and are therefore "indigenous". Téléchargé l'article

LUVANDU MBENZA Maguy1*, NZINGULA PHASI Olivier2, MWELO NGOBE Jules Anatole2, MBINZE KNDENGE Jeremie3, KODONDI KULE KOTO Fridolin2.

Mineral Elements Composition in two varieties of Tomatoes consumed in Kinshasa (Solanum lypersicum var cesariforme et Solanum lypersicum mill)

Two varieties of Solanum Lypersicum (var cesariforme and mill) consumed in Kinshasa in the Democratic Republic of the Congo were analyzed for the determination of mineral composition and the identification of antioxidants. Mineral element analyzes were conducted by the ICP-AES (Atomic Inductive-coupling Plasma Spectrophotometry). Antioxidants have been identified by solution reactions.

By applying the statistical t test of Student (=0.05), the composition of mineral elements differed significantly between the two varieties studied. Mineral elements such as calcium, sodium, magnesium, potassium, zinc, iron, and manganese, copper are more abundant in the variety Solanum lypersicum var cesariform. Polyphenols, flavonoids, and carotenoids are organic antioxidants identified in these samples.

The two varieties of tomatoes analyzed are a significant source of mineral and antioxidants elements. Téléchargé l'article

N’SINABAU EYAY Raïs1*, KASONGO MADIBULAYA Moïse1,2, DIAKIESE MBALA Franchout1, NDONGOSI MUNTU Fiston1, MBULA AWANDJA Clemence1, DIMANDJA OTOKATOKA Albert1.

Evaluation of antibiotic prophylaxis at the General Reference Hospital of N'djili / ISTM- Kinshasa

Antibiotic prophylaxis is one of the most effective means of preventing post-operative infections in so- called clean and clean contaminated surgery. The objective of this study was to evaluate good antibiotic prophylaxis practices in surgery at the N'djili General Reference Hospital. This study was conducted in the surgical department from March 1 2017 to March 30 2018. It covered 253 cases of clean and clean contaminated surgery. Two hundred and two cases were female with a sex ratio of 0.25 in favor of the female sex; the average age was 32.2 years. Only 33% of cases met the indication, duration and recommended dose, 0.4% met the choice of molecule and 5.5% met the timing of administration. Overall compliance was 0.4%. Despite several recommendations in our environments, antibiotic prophylaxis is far from being correctly applied. Téléchargé l'article

 

TELAMANU BAFWANGA Edouard1*, UMBA DI-MBALU Joachim1, NGULU-NSASI Arthur2, BOKI FUKIAKANDA Boble3, PHUKUTA AKENDA KHONDE Mireille3.

Appreciation by the ‘’5M’’ rule the application of sanitary measures on animal products store in cold rooms at Gambela market, Kinshasa, Democratic Republic of Congo

A study was conducted from 1 January to 30 June 2015 in 100 cold rooms at the Gambela market in Kinshasa, DR Congo. The objective was first to evaluate by the "5M" rule (Labor, Environment, Equipments, Raw Materials and Methods) the safety measures as applied to the foodstuffs of animal origin preserved in these cold rooms and to check the existence and functionality of some instruments (wall thermometer, hygrometer, anemometer, emergency generator). The establishments surveyed are those who agreed to answer questions and allowed visits to their facilities and finally practicing wholesale and retail sales. The Excel software was used for data entry and the SPSS 21 program for processing. The results reveal a lack of training, appropriate equipment and medical control for the "Workforce". Many installations are in unhealthy "environments". "Raw materials" are sold in defrost state in sometimes wet and torn packages. We found the absence of some basic "Equipment" (listed above) essential for proper functioning of a cold room. The "methods" of work were inadequate. Téléchargé l'article

 

BISIMWA NGABO Arnold1,2*, MUHANYA NZIGIRE Lambertine1,2, KOKO MUKURU Yves2, KAFIRONGO MANENO Jacques2, APENDEZA MWEMA Christelle3.

Climate change and agriculture production in South Kivu, DR Congo

The aim of this study was to analyze the link between climate change and agriculture production in South Kivu from 2010 to 2015. The study used a secondary database from the Provincial Inspectorate of Agriculture, Fisheries and Livestock of South Kivu and from Lwiro Research Center. A simple linear regression using the least square method was applied to the data. The analysis and data processing were made by SPSS 20 software. Data analysis reveals that climate change (expressed by temperature and maximum precipitation) has significant negative impacts on agricultural production in South Kivu under the studied period.

Political authorities and national or international institutions and organizations in charge of agriculture, nature conservation and ecosystem management should take appropriate steps to prevent climate change and reduce its impact on agricultural production with the aim of ensuring food security and boost the economy of South Kivu. Téléchargé l'article