Cross River University of Technology

About: Cross River University of Technology is a education organization based out in Calabar, Nigeria. It is known for research contribution in the topics: Population & Exergy. The organization has 465 authors who have published 507 publications receiving 2705 citations.

Studies on mosquito repellent activity of cymbopogon citratus (lemon grass) using human volunteers

Abstract: Background: Safety concerns over the use of chemical-based pesticides are provoking intense studies and application of bio-pesticides in disease control and agriculture. Aim: This qualitative study was aimed at testing the repellent efficacy; and suitability of Cymbopogoncitratus (Lemongrass) for the development of natural product-based mosquito repellent. Method: Cymbopogon oil (75ml) was extracted from 200g of fresh Lemongrass leaves using Soxhlet method with n-Hexane as solvent. Human volunteers were topically treated with 2ml and 6ml of Cymbopogon oil applied on exposed areas of the body at night; and observed for 4hrs 30mins. Direct test on mosquitoes in captivity was conducted using a 2-chambered insect box treated with 4 ml of oil in one chamber. Results: Human subjects were free from mosquito bites for 3 hours. Mosquitoes in captivity exhibited active movement away from oil-treated chamber of the box within the first minute of application; 43% repellency and 100% mortality were recorded after 18 minutes. Conclusion: Findings suggest that Cymbopogoncitratus extracts could be used for the production of potent chemical-free and safe mosquito repellent and insecticide for vector control in the fight against malaria and other mosquito-vectored diseases. However further studies and qualitative analyses are necessary to determine suitable concentrations for human topical application.

Efficacy of basalt and granite as coarse aggregate in concrete mixture

Abstract: This present research was on the comparison of the efficacious use of basalt and granite as coarse aggregates in concrete work. In order to obtain the basis for comparison, physical and structural tests were conducted on the different materials of the concrete and the concrete samples respectively. Physical test results revealed that basalt have a specific gravity of 2.8 and 2.5, while granite have a specific gravity of 2.9 and 2.6. In density, basalt have a density of 1554.55kg/m3 while granite had a density of 1463.64kg/m3. Aggregate impact test conducted on both aggregates revealed a percentage of 11.05% for basalt and 12.63% for granite. The following structural tests were carried out: compressive strength tests, flexural and tensile strength test and the comparative results are as follows. Compressive strength for basalt 36.39N/mm2 while 37.16N/mm2 for granite. 24.81N/mm2 tensile strength for basalt while 12.57N/mm2 for granite, 31.83N/mm2 flexural strength for basalt while 27.97N/mm2 for granite. From the above results, it can be deduced that basalt has higher strength properties than granite. Therefore, more suitable for coarse aggregate in achieving higher strength with some quantity of other composition of the concrete mix when compared to granite.

Soil Carbon Dynamics and Soil Properties Influenced by Different Types of Agronomic Land Use in the Forest Zone of Nigeria

Abstract: Assessment of soil carbon dynamics under different agronomic land use could inform soil management practice intervention. Relatively few studies have examined the effects of different agronomic land use beyond routine soil physico-chemical properties, let alone the effects on soil organic matter and critical soil organic matter (SOMc), a basic index of assessing soil degradation. A study was conducted from 2013to 2014 on Alfisols of the humid forest zone of Nigeria to assess soil characteristics under the different agronomic land use, namely; cocoa plantation, cassava farming, natural fallow land and mixed cropping. The aim was to determine accumulation of soil organic matter, some hydropysico-chemical properties and critical soil organic matter so as to reveal the stability of the soils and prescribe soil management strategies. Coefficient of variability (CV %) of the soil properties explained the influence of the land uses on soil properties. Soil characteristics, except sand and sand fractions; but characteristics such as bulk density, WSA, pH, Na and base saturation were not influenced by different types of agronomic land use. Based on the saturated hydraulic conductivity, the studied soil was categorized in very slow to slow conductivity class. Carbon accumulation in the soil varied among the different plantation types with an increasing order: Cocoa plantation > grassland > mixed cropping field > natural fallow > cassava farming. The SOCC values revealed unstable soil structure in cocoa plantation, grassland and mixed cropping farm land and indicated the risk of soil degradation (SOCC = 5–7 %) while cassava farmland was more prone to degradation as the soil suffer from loss of soil structure and is highly susceptible to erosion (SOCC = < 5 %).

Enhancement of Worker’s Productivity Through Recreation and Exercise

Abstract: We are in the era of technology where things are moving fast, so much that man’s work in most cases has become a monotonous routine. There is little opportunity for expressing ingenuity, few chances to satisfy basic social, physical, psychological needs and desires. Evidently, mass phenomena of tension, fatigue, aches, and low body immunity are all pervading. Absenteeism, truancy and loss of skilled manpower through sickness and premature death and declined productivity are manifestation of increasing deteriorating physical fitness. This paper therefore attempts to rationalize the contributions of recreation and exercises for the enhancement of workers productivity. The paper analysis facts from literature and the concepts, characteristics, scope and inherent benefits accruing from participation in recreation and exercises. It concludes that employers who are interested in optimizing performance or maximizing the productivity of their employees must provide recreational facilities and encourage their staff to voluntarily participate in leisure time pursuits.