Volume 29, No. 4 (2023)

CONSTRAINTS OF PROJECT MANAGEMENT IN THE NIGERIAN CONSTRUCTION INDUSTRY

LATEEF AKINTOLA(1), OLUFIKAYO ADERINLEWO(*1), SUNMBO AKANDE (1)

This study addresses the various challenges causing the ineffective practice of project management in Nigeria and proffered possible and workable solutions to them. Data were sourced from construction professionals across Nigeria and 71 responses were obtained from the 109 questionnaires that were administered. After applying the Relative Importance Index and Severity Index methods, it was established that the rankings of the critical factors that hamper contract job completion were significantly different, thus underscoring their respective importance. The recommendations, therefore, emphasized training programs, standard regulation protocol, and effective government policy to ensure effective project delivery in the Nigerian construction industry.

A SPECIALTY LITERATURE REVIEW OF THE PREDICTIVE MAINTENANCE SYSTEMS

DRAGOS-ALEXANDRU ANDRIOAIA(1*), VASILE GHEORGHITA GAITAN(1)

Within the industrial standard 4.0, predictive maintenance has an essential role in production activities, by increasing equipment uptime and decreasing maintenance costs. Predictive maintenance monitors assets through sensors for optimal planning of maintenance operations to keep assets functional. In this paper, the authors perform an analysis of predictive maintenance system, proposed in the specialized literature, highlighting their component elements.

CONTRIBUTION OF PETROGRAPHIC AND GEOCHEMICAL ANALYSES OF THE KIPALA SHALE (CENTRAL BASIN, DRC) TO THE ASSESSMENT OF ITS POTENTIAL AS A HYDROCARBON SOURCE ROCK

DJONIVE MUNENE ASIDI(*1), FLEURY SIMBUNGU ANGBOKO(2), THOMAS KANIKA MAYENA(3), RUTH ILUNGA MULAJI(1), ANGE THIJENIRA LOKETO(3), FREDERIC MAKOKA MWANZA(3), LEVESQUE MAKUKU MBO(1), RACHIDI OPULUKU(1), JEAN IYOLO LUNGEMBO(1)

A geological study of the Kipala region, in the "Cuvette Centrale" of the Democratic Republic of Congo, has identified two groups of shales: the dark greasy facies, interbedded with the brownish-gray facies. Their high Total Organic Carbon (TOC) content (11 % TOC on average for the dark greasy shales, compared with 8 % for the second group) classifies them as very good hydrocarbon source rocks, according to the criteria of Epistalie et al. Field and laboratory data suggest that the rocks studied were deposited in a lagoon connected to the sea by an intermittently closing channel.

PHYSICAL-MECHANICAL PERFORMANCES OF STEERING WHEEL COVER LEATHERS IN SPECIAL CONDITIONS

MADALINA IGNAT, ANDREI DUMITRU, BOGDAN RUSU, ROXANA CONSTANTINESCU, CIPRIAN CHELARU(*)

The steering wheel is among the important components of a vehicle, through it having full control over its direction. It is made of a metal base covered with a polymeric material. To improve the look and feel of a steering wheel, usually it is covered by leather. Choosing the material for covering the steering wheel must be done responsibly, because depending on the material, it can generate a certain type of comfort when using the steering wheel. Thus, the current work aims to evaluate the durability and wear resistance of different types of leather coatings used in automotive steering wheels. A series of tests were performed on leather samples before and after exposing them to special conditions (high\low temperature, humidity, UV) like tensile strength and elongation, tear strength, tear load, surface softness, color fastness and flex resistance. All the tests were performed according to actual standards in ICPI accredited laboratory. The results of the experiment showed that the durability and wear resistance of the leather varied significantly depending on the type of coating. Overall, the study provides valuable insights into the characteristics of different types of leather and can help future research involved in developing more durable and long-lasting steering wheel cover leathers.

TRANSMISSION BELTS PERFORMANCE IN NORMAL AND HEAVY-DUTY CONDITIONS

MADALINA IGNAT, BOGDAN RUSU, ANDREI DUMITRU, ROXANA CONSTANTINESCU, CIPRIAN CHELARU(*)

The main purpose of this article was to study the behavior of vehicle transmission belts in conditions similar to real ones, which can appear during their use. Transmission belts can be classified into several categories, but depending on their function, can be belts that work in dry conditions or immersed in oil. In this study, were analyzed both types of transmission belts. The samples were subject to different physical-mechanical tests: determination of hardness, density, thickness, abrasion, flex resistance, tensile strength and percentage extension and also to various conditions like, high and low temperature, immersion in liquids (oil, toluene, diesel). All the tests were performed before and after exposure, according to actual standards in ICPI accredited laboratory. Microscopy studies were done before and after the exposure to various factors, in order to appreciate the damage degree. Also, chemical specific analyses were made for determining the transmission belts composition. The findings from this study provide important insights into the behavior of transmission belts under different operating conditions.

SOME POSSIBILITIES OF THE AERIAL DRONES USE IN PRECISION AGRICULTURE – A REVIEW

IOSIF IOJA(1*), VALENTIN NEDEFF(1,2), MARICEL AGOP(3), FLORIN MARIAN NEDEFF1*

Precision agriculture, together with remote sensing and vegetation indices, represents a modern correlation that maximizes efficiency and sustainability in farmland management, contributing to more efficient and responsible production. Remote sensing in agriculture is an important technology that uses data from sensors mounted on satellites, drones, and aircraft to monitor and evaluate agricultural land. Vegetation indices are needed in agricultural remote sensing and precision agriculture because they provide quantitative and objective information on agricultural crops contributing to more efficient, sustainable and cost-effective land management.

COMPARATIVE ANALYSIS OF NON-COOPERATIVE SPECTRUM SENSING TECHNIQUES IN COGNITIVE RADIO NETWORK

HAMMED OYEBAMIJI LASISI(1), OLAJIDE MICHEAL ODOFIN(1*), MUHAMMED BABAJIDE HAMMED(1), IDOWU OLAMIDE HUSSEIN(1)

Cognitive radio (CR) is an integral system in telecommunications technology that gives unlicensed users access to licensed spectrums via dynamic spectrum access (DSA), to promote spectral efficiency. A significant operation in cognitive radio system is spectrum sensing. This paper evaluates and compares two of the major non-cooperative sensing techniques (energy and cyclostationary feature detector (CFD)) in order, to determine which gives better performance. Matlab Simulink was used as modeling and simulating tool for the evaluations. From the results, energy detector was simpler and faster but unlike CFD exhibited poor performance in corrupt channels.

RESEARCH ON THE RECOVERY OF SOME AGRICULTURAL WASTE FOR THE MANUFACTURE OF COMPOSITE MATERIALS WITH CLAY MATRICES

SURDU ELENA(1), FARCAȘ-FLAMAROPOL CLAUDIA-DANA(1*), CÂRDEI PETRU(2), DURBACĂ ION(1), SPOREA NICOLETA(1)

The article describes the results of the research carried out for the systemic description of the manufacturing technological processes of composite materials with clay matrix and insert from agricultural waste. The objectives of these researches include the valorization of agricultural waste and cheap and abundant resources to obtain composite materials usable in civil constructions or various rural developments, with properties superior to existing ones, for example adobe or clay bricks. The article describes the materials used, the technology of obtaining, the dependence between the output parameters and the input and control parameters.