Double Sampling Auxiliary Information Chart And Exponentially Weighted Moving Average Auxiliary Information Chart, Both Based On Variable Sampling Interval, And Measurement Errors Based Triple Sampling Chart

The concept of using auxiliary information (AI) in control charts is growing in popularity among researchers. Control charts using the AI technique have been found to be more effective than control charts without the AI technique. The first objective of this thesis is to develop a variable sampling interval (VSI) double sampling (DS) chart using the AI technique (called VSI DS-AI chart) for monitoring the process mean. The charting statistics, optimal designs and implementation of the VSI DS-AI chart are discussed. The steady-state average time to signal (ssATS) and steady-state expected average time to signal (ssEATS) criteria are used as the performance measures of the proposed VSI DS-AI chart. The ssATS and ssEATS results of the VSI DS-AI chart are compared with those of the double sampling AI, variable sample size and sampling interval AI, exponentially weighted moving average AI (EWMA-AI) and run sum AI (RS-AI) charts. The comparison reveals that the VSI DS-AI chart performs better than the competing charts for all shift sizes, except the EWMA-AI and RS-AI charts for small shifts

Application of Resistivity Sounding In Environmental Studies: A Case Study of Kazai Crude-Oil Spillage Niger State, Nigeria

A pipeline conveying crude oil from Escravos via Izom ruptured in the year 2000 and polluted the Kazai area, although the ruptured pipe was replaced and the site cleaned up, an examination of the point of spillage two years later gave the impression that the pipeline might be still leaking. The present work presents the use of Vertical Electrical Soundings (VES) techniques, and systematic trenching, to determine the source of this environmental problem. A total number of eight soundings along two profiles were carried out around the point of spillage, and data analysis revealed that the area is predominantly clayey in nature, and that the pipes are no longer leaking. Due to the plasticity of the clay when wet, it expands when in contact with rainwater and, as it does so, it entrapped any oil existing around it. However, when not in contact with water in the dry season, the clay shrinks and cracks, thereby releasing the trapped oils. This mechanism continued seasonally, and the oil released during the dry season, is the one responsible for the apparent leakage of the pipeline. Geoelectric models in the form of Vertical Isoresistivity Sections (VIS) and Isoresistiviy Maps were plotted. These were used to delineate the polluted zones, which were recommended for excavation and refilling. Keywords: Vertical Electrical sounding, Geoelectric Models, Isopach map, Isoresistivity Ma

Assessment of Wash-Borehole Water Quality in Gombe Metropolis, Gombe State, Nigeria

Groundwater from wash-boreholes in Gombe Metropolis North-Eastern Nigeria was investigated to ascertain its quality status and suitability for drinking and domestic uses. Water samples were collected in the three wards of the Metropolis, namely Tudun Wada (ward A), Pantami (ward B) and Jeka da Fari (ward C). The physicochemical and bacteriological analyses conducted were in accordance with the standard procedures. The mean values for temperature, pH, electrical conductivity (EC), total dissolved solids (TDS), sulphate (SO42-), nitrate (NO3-), fluoride (F-), hardness, copper, manganese, total and faecal coliforms were within the permissible limits recommended by the Nigerian Standard for Drinking Water Quality (NSDWQ) and also, below the World Health Organization (WHO) standards with the exception of nitrate (NO3-). However, turbidity and nitrite (NO2-) in all the three wards, total iron in wards B and C, as well as the phosphate (PO43-) in ward C, had mean values above the NSDWQ and also, beyond the WHO standards with the exception of nitrate (NO3-). Thus, as a preventive measure to control the health threat associated with consumption of nitrate (NO3-), nitrite (NO2-), phosphate (PO43-) and iron from the water source, wash-borehole water in Gombe Metropolis should only be used for bathing and washing. The study therefore, stresses on the need that public should be provided with an alternative water source for drinking and cooking purposes. Key words: Wash- borehole, Water quality, Monitoring, Gombe metropolis

PRENATAL AND POSTNATAL DEVELOPMENT AND COMPARATIVE ANATOMY OF THE MANDIBLE OF THREE BREEDS OF SHEEP: A GROSS STUDY

This study aims to evaluate and compare the development of the mandible and gross anatomy in three breeds of sheep. A total of 180 and 720 prenatal and postnatal samples were used respectively, their skulls were macerated and mandibles detached. In prenatal life, the mental and mandibular foramina were rudimentary in the late 1st trimester and 2nd trimester and developed in the 3rd trimester. The alveolus and mandibular canal differentiated in the 3rd trimesters respectively. In the postnatal life, the ventral border was convexed in Uda but flat in Balami and Yankasa breeds. The angular part of the ramus was thin in Uda and thick in Balami and Yankasa. The mandibular tuberosity was absent in Balami and Yankasa but present in Uda. There was a small accessory foramen caudal to the mental foramen just below the first premolar teeth in the Uda and Yankasa. The labial surface was wide and rough in Balami and Uda but smooth in Yankasa. The medial surface was flat in the young postnatal and convexed in the adult postnatal. It was brought to a conclusion that the mandible in the Nigerian breeds undergoes various morphological changes from prenatal and postnatal ages with peculiar differentiating features

Socio-economic Impact of Flooding on the Riverine Communities of River Benue in Adamawa State, Nigeria

This paper examines the impact of floods on the socioeconomic lives of residents of the flood plain of River Benue in the Adamawa area. The specific objectives of the paper include examining people’s perception of the causes of flooding in the study area, assessing the impacts of flooding on the socioeconomic activities in the study area, analyzing the People’s Response/Adjustment to Flood in the study area. Three Riverine communities were purposively selected and data for the study was elicited through questionnaires administered to randomly selected respondents in the selected riverine communities in the area. The results obtained indicate that majority of the respondents over 80% are aware of the devastating effects of flooding but they fail to act because of their preference of occupying the location despite their experience. Thousands of hectares of farmlands and other properties have been destroyed by flood over the years. Another finding shows that the impact of flood on transportation is, perhaps, the most devastating such that agricultural productivity in the area is limited as a result of lack of effective means of mobility. Changes in modal split were also found to be associated with the flood regimes. Traditional responses to the menace of flooding have been on the increase due to the ad hoc manner of government participation in providing an enduring solution. The rescheduling of field crops planting and levee construction were among the common responses of the people. Keywords: Flood, River Benue, Transportation, Socio-economic, Environmen

Screening of sweet potato feathery mottle virus resistant sweet potato (Ipomoea batatas L., Lam.) cultivars in Kebbi State, Nigeria

Sweet potato is a food security crop because of its ability to withstand adverse climatic conditions. This security, however, is being threaten by viral diseases and use of resistant cultivars remain the best management. This research was conducted to screen cultivars of sweet potato against sweet potato feathery mottle virus (SPFMV) infection. The treatments consisted of five cultivars coded as CV1, CV2, CV3, CV4 and CV5, respectively. The asymptomatic experimental plants were established, maintained under screen house conditions and graft-inoculated using infected vines which were tested SPFMV positive using both Double Antibody Sandwich Enzyme-Linked Immunosorbent Assay (DAS-ELISA) and Polymerase Chain Reaction (PCR). The experiment was laid out in Completely Randomized Design (CRD) and replicated three times. Results obtained from disease incidence and symptom severity indicated that there was significant difference (P <0.05) among cultivars in their reaction to SPFMV infection. CV2 had the highest mean disease incidence (60.67%) while, CV3 had the lowest mean disease incidence (36.67%). CV1, CV3, and CV5 have the same lowest mean symptom severity score of 2.00 while, CV2 had the highest mean severity score of 4.00. Based on the reaction of the cultivars after inoculation, it could be concluded that, all the cultivars screened were susceptible to SPFMV but CV1, CV3 and CV4 cultivars have some degree of resistance to SPFMV infection and were therefore recommended for use by the farmers in the study area. This is the first research that screened sweet potato cultivars for resistance to SPFMV in Kebbi State, Nigeria

The influence of board gender diversity on financial performance of listed companies in Nigeria / Armaya’u Alhaji Sani … [et al.]

This study examined the impact of board gender diversity on the financial performance of listed companies in Nigeria. Using a sample of 400 firmyear observations for the period of 2012-2016. The data for the study were extracted from the annual reports of the sampled firms and the Thompson Reuters DataStream. The data was analysed by means of the Panel Corrected Standard Error (PCSE). The study found that gender diversity (female directors) influenced the financial performance of companies listed on the Nigerian Stock Exchange. The findings supported the argument that gender diversity enhances the financial outcomes of firms. Consistent with the Resource Dependency Theory, the result implied that female directors contribute to the upper echelon of the firm’s decision. The findings inform regulators and other stakeholders on the roles of female directors in explaining the corporate financial outcomes

Embryonic Development and Comparative Anatomy of the Mandible

Objective: This study was designed to determine the ossification time and pattern of the mandible. Methodology: Three hundred and fifty (350) wasted fetuses consisting of 70 Balami, 140 each of Uda and Yankasa breeds whose crown vertebral rump length ranged from 3.0-15 cm were used. The fetuses were processed using the Alizarin technique and the mandible was dissected from the head for stereography. Result: The result revealed that the first part of the mandible to develop was the body and mental foramina at the 42nd–44th days of gestation while the coronoid process, rami, and condyloid process develop later at different time points. In addition, the mandibular foramina remained undeveloped in all age groups. Interestingly, the mandibular canal began ossification earlier in the Yankasa breed compared to other breeds. It was shown to arise from a cartilaginous tissue at the medial and lateral surfaces of the body and dorsally remained opened and undifferentiated from the teeth alveoli of the lower jaws in the 7 age groups. Conclusion: It was therefore concluded that the mandible arises from three ossification centres at the body, rami, and coronoid process. These segments develop at different time intervals in the three breeds of sheep with Yankasa mandible ossifying and progressing faster than in Balami and Uda.   Doi: 10.28991/SciMedJ-2021-0301-3 Full Text: PD

An Investigative Study on Impact of Frequency Dynamics in Load Modeling

Load modeling plays a significant impact in assessing power system stability margin, control, and protection. Frequency in the power system is desired to be kept constant, but in a real sense, it is not constant as loads continually change with time. In much literature, frequency dynamics are ignored in the formulation of load models for the basic assumption that it does not affect the models.  In this paper, the composite load model was formulated with Voltage-Frequency Dependency (V-FD) on real and reactive powers and applied to estimate the load model. 2- Area network 4- machines Kundur test network was used for testing the developed model.  The model was trained with measurements from a low voltage distribution network supplying the Electrical Engineering department at Ahmadu Bello University, Zaria. Both training and testing data were captured under normal system operation (dynamics). To evaluate the V-FD model performance, Voltage-Dependent (VD) model was examined on the same measured data. The work makes use of the Feed Forward Neural Network (FFNN) as a nonlinear estimator. Results obtained indicate that including frequency dynamics in modeling active power reduces the accuracy of the model. While in modeling reactive power the model performance improves. Hence, it can be said that including frequency dynamics in load modeling depends on the intended application of the model