Rivers State University of Science and Technology

About: Rivers State University of Science and Technology is a education organization based out in Port Harcourt, Rivers, Nigeria. It is known for research contribution in the topics: Population & Threatened species. The organization has 1826 authors who have published 1833 publications receiving 15183 citations.

Long‐term changes in population size and the age structure and sex ratio of waterbuck in a Sudanian savannah of Burkina Faso

Abstract: The waterbuck (Kobus ellipsiprymnus), though widespread throughout Africa, is suspected to be declining overall. Data on population numbers and structure are lacking for many parts of its range, especially in West Africa, where the subspecies defassa is found. The aim of the present study was to evaluate the abundance, distribution and attributes of waterbuck populations from the Nazinga Forest Reserve, southern Burkina Faso. We investigated waterbuck population trends in the park using transect data collected in 1985–2019. For the more detailed analyses of population structure and distribution of the animals, we used census data gathered during 2019. Most animals were adults (46.6%), and the sex ratio was heavily skewed towards females (5:1). Most animals were concentrated along the larger rivers. There was no influence of poacher activity on waterbuck distribution. In the long term (1985–2019), the population dynamics of waterbuck can be roughly divided into two main periods: a phase of population increase from 1985 to 2005, and one of ongoing population collapse from 2007 to 2019. Although the declining population trend was obvious, coefficients of determination were low indicating that the years explained poorly the number of individuals and the number of sightings obtained. Waterbuck numbers in the Nazinga Forest Reserve are declining, but we found no single reason to explain this trend. It is likely that a combination of factors, including global warming (increased aridity) and illegal activities such as poaching, is responsible. Because there are probably multiple reasons for the observed waterbuck population decline in our study area, we suggest that a multifaceted approach should be adopted in order to enhance the conservation status of the local waterbuck populations.

Multi-objective optimization for a helicopter pilot using genetic algorithms

Abstract: This work aims to develop an artificial intelligence for a helicopter pilot. That is, a system that learns to fly a helicopter the way a human pilot would. It draws on the benefits of using inverse simulation and genetic algorithms to model systems similar to human process. The goal is to define tasks for the helicopter and have the pilot find control settings that carry out those tasks. The inverse simulation technique generates the control inputs required for a desired set of motion outputs. Genetic algorithms (GA) generate feasible solutions to the inverse problem in which the helicopter's trajectory is defined as a set of way-points. The continuous controls encoding method was implemented in flying a longitudinal acceleration/deceleration maneuver. The helicopter pilot was formulated as a multi-optimization problem with four objectives imposed as penalties. The work proposed an optimization approach termed maxPenalty, which compared and returned the biggest of the four penalties. The GA attempts to maximize the fitness and while minimizing the pilot workload. The work shows some aspects of the GA-produced flight that are human-like, and the fact that humans do not move along precise trajectories.

The Pollution Potentials of Open Drains in Port Harcourt, Nigeria

Abstract: Studies the layout of system, chemical, and physical characteristics of wastewater flowing in open drains in the city of Port Harcourt, Nigeria. Shows that some open drains are well constructed and lined, while most of the others are not. Wastewater in these drains, especially in high density areas, are dark in appearance with high levels of turbidity, total solids, BOD, chloride and hardness. The rivers into which these drains discharge are always contaminated with refuse items, with the result that aquatic life is endangered.

Field evaluation of four sweet potato cultivars for yield and sweet potato weevil (Cylas puncticollis Boh.) damage during the early cropping season in South Eastern Nigeria

Abstract: Four sweet potato cultivars (TIS 87/0087, TIS 8441, TIS 2532 OP. 1. 13 and Ex Igbariam) were evaluated for yield and damage of C. puncticollis during the period June to October in 1999 and 2000, respectively. The trials were conducted in a randomized complete block design and replicated three times. Plants were sampled forthnightly for tuber yield and C. puncticollis incidence and damage. Marketable tubers were recorded at 8 weeks after planting (WAP) and this increased with the age of the plant. TIS 87/0087 consistently gave higher marketable tuber numbers at all the different times of harvesting than other cultivars. There was no incidence of C. puncticollis on tubers between 8 to 14 WAP. However, C. puncticollis damage was higher in 1999 than the year 2000 at 16 WAP. Although the percentage tubers infested and severity of damage did not significantly differ among the cultivars. TIS 2532. OP. 1. 13 showed consistent high incidence and severity of damage. [Niger Agric. J. 34 (2003): 81-86]

Maintenance optimization of a marine heat exchanger subject to fouling

Abstract: Engineers are often expected to improve the requirements of process plants to increase their efficiencies. Processes which use heat transfer equipment need to be frequently maintained for these reasons. With a view to optimize the performance of the equipment, this paper therefore provides the results of two maintenance strategies to combat the menace of fouling in order to increase shell and tube heat exchangers performance. The high-pressure water jetting and chemical cleaning techniques were used in this work for units A and B heat exchangers of a process plant. Periodic monitoring was also used to predict the performance of the equipment. This approach capitalized on the overall heat transfer, pressure drop and fouling factor to optimize the performance of marine heat exchangers. Performance data were taken for a period of ten weeks before and after cleaning from 15kW heat exchanger units A and B, which were under the same condition of deterioration recommended prior to maintenance. The results revealed that before the heat exchanger units were shut down for maintenance, the overall heat transfer was 9778.4kw, which was likeable to 65.19% of the design value, while that of unit B rose to 12255.90kw, which is 81.71% of the design value. Furthermore, after the maintenance the overall heat transfer effectiveness of unit A rose to 14563.46kw, which is 97.19% of the design value. The results proved that high pressure water jetting method is best in combating fouling for performance recovery.