Open Access Original Research Article

Comparative Study for the Effect of Rigid and Semirigid Diaphragms on Reinforced Concrete Walls

T. S. Mustafa

Journal of Engineering Research and Reports, Page 1-8
DOI: 10.9734/jerr/2019/v8i116979

Rigid diaphragm is generally an acceptable option in most of the seismic design codes in which the in-plane deformability is not permitted because of the infinite in-plane stiffness properties.  Several building configurations may exhibit significant flexibility in floor diaphragms and accordingly using the semirigid diaphragm is recommended as significant in-plane deformation does occur.  In this study, a comparative study by using rigid and semirigid diaphragms is performed to identify the related effect on the reinforced concrete (RC) walls. In this study, a numerical study for a twelve-story building with dual system of RC columns and walls is performed. All geometrical and loading properties have been kept constant while using two types of diaphragm as rigid (RD) and semirigid (SRD). The seismic performance of the studied two structures was evaluated in terms of the fundamental period, maximum inter-story drift, maximum base shear and stresses on RC walls. Generally, RD produce results nearly identical to those of SRD for base shear, story displacements and inter-story drifts as the slab is sufficiently thick and membrane deformation due to lateral loading is negligible. Compared to SRD, using RD led to increase the internal moment and shear forces resulted from the seismic loads and acting on the RC walls while the resulting vertical loads are nearly identical.

Open Access Original Research Article

Strength and Dimensional Stability of Cement-bonded Boards Manufactured from Mixture of Ceiba pentandra and Gmelina arborea Sawdust

E. A. Adelusi, K. O. Olaoye, F. G. Adebawo

Journal of Engineering Research and Reports, Page 1-10
DOI: 10.9734/jerr/2019/v8i116980

Cement bonded boards of 6 mm in thickness were produced from the mixture of Ceiba pentandra and Gmelina arborea sawdust. The influence of weight to weight proportion of C. pentandra and G. arborea blended at levels of 100:0, 75:25, 50:50, 25:75 and 0:100 in mass and mixing ratios of cement to wood 2:1 and 3:1 on Modulus of Rupture (MOR), Modulus of Elasticity (MOE) Water Absorption (WA) and Thickness Swelling (TS) properties of the experimental boards were examined for 24 h and 48 h immersion in cold water. The mean values for MOE and MOR were from 2479.50 to 5294.30 N/mm2 and 0.82 N/mm2 to 3.02 N/mm2 respectively, while the mean values for TS and WA after 24 h in cold water were from 0.53% to 7.35% and 14.8% to 52% respectively, whereas after 48 h in cold water immersion the mean values for TS and WA were from 2.37% to 10.48% and 16.5% to 69.5% respectively. It was observed that, increase in G. arborea (75%) to C. pentandra (25%) and mixing ratio 3:1 (cement/wood) was responsible for increase in MOR and MOE and decrease in TS and WA. The result shows that cement-bonded boards can be manufactured from Ceiba pentandra sawdust when mixed at certain blending proportion and ratio.

Open Access Original Research Article

Optimum Manpower Allocation in Health Care Using Statistical Process Control

William E. Odinikuku, Jephthah A. Ikimi, Ikechukwu P. Onwuamaeze

Journal of Engineering Research and Reports, Page 1-9
DOI: 10.9734/jerr/2019/v8i116981

In many countries manpower problems in the field of health care are regular items on the agenda of policy makers. To avoid mismatches between demand of care and supply of care on national and regional levels, manpower planning models and methods are used to determine adequate numbers of medical specialists to fulfill the future demand of care. Inadequate or inefficient allocation of manpower to various departments in an organization or workplace can lead to undesired outcomes which may include: down time, reduced productivity, workers fatigue, increased production costs, etc. As a result of the above stated problem, there is need to devise a statistical model that will ensure optimal allocation of manpower.

In this study, the optimum allocation of two hundred and fifty two general nurses to fifteen wards at a hospital code named WCH located in South-South geopolitical zone, Nigeria was achieved using statistical process control. The study involved the analysis of data obtained from our hub of study for a period of two months. The C-chart was used to check if the process of allocation was in control or not.

The result obtained from the study showed that the manpower allocation process was out of statistical control as the allocation of the children emergency ward was outside the upper control limit of the c-chart plot.

Open Access Original Research Article

Analysis of Fiber Loss Mechanisms in Communication System to Simulate Different Attenuation

Khadija Tut Tahira, Md. Omar Faruk, Tanvina Aktar Ruma, Tonusree Saha, Md. Mostafizur Rahman

Journal of Engineering Research and Reports, Page 1-15
DOI: 10.9734/jerr/2019/v8i116982

The fiber optic communication system can transmit data a rate of 10 GB/S or more, over a maximum possible distance with less attenuation. In this research a low loss optical fiber has been simulated. The simulation is done by MATLAB Software. This research deals with different loss mechanisms in optical fiber communication. A number of mechanisms are responsible for the signal attenuation within optical fibers. As the optical signal propagates over long stretch of fiber, it becomes attenuated because of absorption, scattering, fiber bends by material impurities, and other effects. The absorption loss at 1310 nm wavelength of light is significantly very low. It is also observed that the scattering loss decreases as the wavelength of light increases and the same case for bending loss; for link loss the fiber attenuation is increased gradually with the increasing fiber distance. In this research it is shown that the attenuation for multimode fiber is greater than single mode fiber at wavelength 1550 nm, attenuation level for 1550 nm wavelength is lower than 1310 nm wavelength. It is also shown that there are great attenuation between glass and plastic optical fiber and large attenuation between plastic and Plastic Clad Silica optical fiber. Different fiber types and their properties such as attenuation or loss are also observed. The performance improvement of the proposed different loss, such as absorption loss, rayleigh scattering, bending loss, link loss for different wavelength and different material within the various loss mechanisms in fiber optic communication is shown through simulations.

Open Access Original Research Article

Enhancing Water use Efficiency of Maize under Deficit Irrigation: the Case of Moisture Deficit Areas of Tigray, Ethiopia

Kiflom Degef Kahsay, Kidane Welde Reda

Journal of Engineering Research and Reports, Page 1-6
DOI: 10.9734/jerr/2019/v8i116983

Maize (Zea Mays L.) is one of the most important food crops worldwide. In Ethiopia, it is one of the leading food grains selected to assume a national commodity crop to support the food self-sufficiency program of the country. Maize is fairly sensitive to water stress and excessive moisture stress. This is due to variation in sensitivity of different growth stages to water stress. The study was conducted to determine the water use efficiency of maize under deficit irrigation practice without significant reduction in yield and to identify crop growth stages which can withstand water stress. The experiment was conducted at the Alamata Agricultural Research center experimental site Kara Adishabo Kebele, Raya Azebo district. The experiment was laid out in randomized complete block design (RCBD) with three replications and six levels of irrigation water applications as possible treatments. Analysis was done to yield and water use efficiency of maize using R statistical software and the mean difference was estimated using the least significant difference (LSD) comparison. The highest grain (33.72qt/ha) and biomass yield (148.4qt/ha) was obtained from the 50% deficit irrigation at late growth. The maximum irrigation water use efficiency was obtained from both 50% deficit at all the four growth stages (0.5418 kg/ha) and at 50% deficit at late growth stage (0.446 kg/m3). And by comparing the grain yield obtained at the 50% deficit at late growth stage (33.72 qt/ha) and grain yield obtained at 50% deficit at all growth stages (23.34 qt/ha), the 50% deficit at late growth stage shows better result. The 50% deficit of crop water requirement did not affect the yield components (plant height & number of cobs per plant) of maze. Therefore applying irrigation water by reducing the crop water requirement by 50% at the late growth stage has a significant contribution for sustainable and efficient irrigation water utilization at moisture deficient areas without a significant loss on grain and biomass yield.