Engineering Properties of Polyethylene Terephthalate Fibre Reinforced Concrete with Fly Ash as a Partial Cement Replacement

This research is funded by African Union Commission (AUC) and Japan International Cooperation Agency (JICA) Abstract Although concrete has good qualities that make it suitable for a wide range of applications in the construction industry, it also has undesirable properties; one of which is its low tensile strength. Numerous studies are being carried out to improve the undesirable features of concrete by using substitute materials such as industrial, manufacturing, agricultural as well as domestic wastes. In Africa, there is a pressing need for reusing and recycling waste materials. Following the extensive use of concrete in the vast construction industry, the incorporation of wastes like Polyethylene Terephthalate (PET) bottles and fly ash to improve its quality is a sensible intervention. PET bottles, used for packaging of beverages, and fly ash, generated during the combustion of coal, are causing severe environmental degradation. This study evaluated the effects of using PET fibres and fly ash on the performance of concrete. PET fibres with an aspect ratio of 50 (100mm length and 2mm width) were incorporated in the concrete mix at percentages of 0.5, 1.0 and 1.5% by weight of cement. On the other hand, fly ash was introduced as a cement replacement at percentages of 20, 22.5, 25, 27.5 and 30% by weight of cement. The performance of the modified concrete was evaluated based on workability, compressive strength, and splitting tensile strength. The combination of 1.5% PET fibres and 27.5% fly ash resulted in 33.45% tensile strength improvements, while keeping the workability and compressive strength unaffected. Keywords: Concrete, polyethylene terephthalate; fly ash; ordinary Portland cement; aggregates; workability; compressive strength; splitting tensile strength; aspect ratio DOI: 10.7176/CER/11-6-05 Publication date:July 31st 201

Business Networking and Performance of Women-Led Enterprises: An Empirical Investigation in Nairobi County, Kenya

Women entrepreneurs have been considered to use business networking as a determinant to enterprise performance. A key question that arises i

PENGARUH KECERDASAN EMOSIONAL, LINGKUNGAN KERJA DAN KOMITMEN PEGAWAI TERHADAP PRODUKTIVITAS KERJA PADA BADAN PERENCANAAN PEMBANGUNAN, PENELITIAN DAN PENGEMBANGAN DAERAH KABUPATEN TOJO UNA-UNA

The study determines and analyzes simultaneous and partial influence of emotional quotient, work environment, and commitment on productivity in The Agency of Development Planning, Research, and Regional Development of Tojo Una-Una District. It applies quantitative approach by taking 38 officials in The Agency of Development Planning, Research, and Regional Development of Tojo Una-Una District as samples through census method. Technique of analysis is multiple linear regressions with hypotthetical test by using confidence level of α = 0,05 with SPSS version 22.00. validity test runs with corrected-item total correlation with minimum value of r=0.3. Reliability test applies cronbach alpha coefficient with coefficient limit of  α >0.6. the results shows that emotional quotient, work environment, and commitment simultaneously have significnat influence on officials’ productivity in The Agency of Development Planning, Research, and Regional Development of Tojo Una-Una District with Fvalue of 2.045>Ftable  of 0.049 on sig 0.000. The variable of emotional quotient has significant influence on productivity with tvalue of 1.523>ttable of 0.137 on sig 0.000; work environment has positive influence but insignificant on productivity with tvalue of 1.445>ttable of 0.158 on sig 0.162; commitment has significant influence on productivity tvalue of 4.518>ttable of 0.677 on sig 0.000

Modeling drying of seed maize using super absorbent hydrogel under hermetic conditions

The objective of this study was to establish the feasibility of applying the Page, Two term exponential, Newton, Logarithmic and Henderson and Pabis mathematical drying models for predicting the drying kinetics of seed maize using super absorbent hydrogel under hermetic conditions. To achieve this, the study was conducted using hydrogel to seed maize ratios by weight of 0:1, 1:5, 1:10 and 1:15 at four different drying temperature levels of 25oC, 30oC, 35oC and 40oC at different initial seed maize moisture contents of 16%, 28% and 53% (dry basis). The moisture data obtained were fitted into the five drying models using non-linear regression analysis (MS Excel 2003TM) based on the minimization of sum of squares by adjusting the model constants. The coefficient of determination (R2), root mean square error (RMSE) and chi-square (X2) were criteria for selecting the best model. High values of coefficient of determination (R2 > 0.95) were obtained for all the five drying models while the corresponding values of X2 and RMSE were in the range of (0.0016-0.0141) and (0.0400-0.3045) respectively. As a result Logarithmic model was the best fitted model with R2 (0.9749-0.9876) and the weakest values of X2 (0.0016-0.0036) and RMSE (0.04-0.128)

Effects of Recycled Tyre Steel Fibres on the Compressive, Splitting Tensile and Flexural Strengths of Structural Lightweight Concrete Using Palm Kernel Shells as Partial Replacement of Coarse Aggregates

The improper handling and disposal of waste tyres in many African countries is still a serious problem which has caused environmental and health hazards. Like waste tyres, the proper reuse of agricultural wastes, such as palm kernel shells, is also a challenge as the production has increased over the years. In the field of civil engineering, effort have been made to recycle waste tyres and palm kernel shells in concrete production to mitigate some of the environmental problems arising from these wastes. The recycling of such waste for civil engineering applications has been heightened with the development of new technologies. This study was carried out to evaluate and assess the effects of recycled tyre steel fibres and palm kernel shells on the compressive, splitting tensile and flexural strengths of structural lightweight concrete, using recycled tyre steel fibres for reinforcement and palm kernel shells as partial replacement of coarse aggregates. Recycled tyres steel fibres were added in normal-weight concrete at 0.25, 0.50 and 0.75% (Viz., 6, 12 and 18 kg/m3) content and aspect ratio of 20, 40, 60, 80 and 100% to determine the optimal fibres content and aspect ratio. The results show that recycled tyres steel fibres obtained from pyrolysis can improve the compressive and splitting strengths of normal-weight concrete. The optimal fibres content and aspect ratio were used with palm kernel shells at 25, 50, and 75% content to determine the optimal partial replacement of coarse aggregates with palm kernel shells. The maximum compressive and splitting tensile strengths values were obtained at an aspect ratio of 80, palm kernel shell content of 25% and steel content of 0.50%. Normal-weight concrete strength values in flexure were higher than lightweight concrete made with optimal values. Additionally, beams with 25 and 50% content of palm kernel shells with optimal fibre content and aspect ratios qualified as structural lightweight concrete. Keywords: palm kernel shells, recycled tyres steel fibres, waste tyres, lightweight concrete, normal-weight concrete, compressive strength, splitting tensile strength and flexural strength. DOI: 10.7176/CER/11-6-06 Publication date:July 31st 201

Determinants of Effectiveness of Employee Performance Appraisal System in Institution of Higher Learning: A Survey of Public Universities in Nakuru County

A performance appraisal system is important to any organisational work performance;  it determines the organization’s success or failure. Several studies such as Nzuve (2007), Yee and Chen (2009) define PA as a means of evaluating employees’ work performance over a given period of time. According Horsoo (2010) reports that employees viewed performance appraisal as discriminatory, punitive and judgemental processes, where cronyism and biased considerations dominated objectivity and thus ineffectiveness of the appraisal system.  The main objective of the present study was to assess the effects of job related factors on the effectiveness of employee performance appraisal system in institutions of higher learning in Nakuru County.  The study adopted a survey design.  The study population comprised of all academic personnel in public universities Nakuru County.   A sample size of 224 respondents was selected randomly from a population of 507.  This number was distributed among academic staff across all the departments and sections.  The instrument for collecting data was a questionnaire which was used to collect get both qualitative and quantitative data.  The questionnaire was distributed amongst the all academic staff in public universities in Nakuru County.  A total of 220 out of 224 academic staff completed questionnaires, which represented all public universities in the county with varying demographic backgrounds.  Analysis of quantitative data was done to test hypothesis using the ANOVA and regression analysis.  The results indicated that job related factors (training and development, promotion and tasks in organisation had a positive impact on the effectiveness of employee performance appraisal system among the selected institutions of higher learning in Nakuru County.  An effective performance appraisal system enables organizations realize their goals as well as employees personal growth. Keywords: Employee performance appraisal system, organisational work performanc

Personality as a Determinants of Effectiveness of Employee Performance Appraisal System: A Survey of Public Universities in Nakuru County

A performance appraisal system is important to any organisational work performance; it determines the organization’s success or failure. Several studies such as Nzuve (2007), Armstrong (2012), Yee and Chen (2009) define PA as a means of evaluating employees’ work performance over a given period of time. According Horsoo (2010) reports that employees viewed performance appraisal as discriminatory, punitive and judgemental processes, where cronyism and biased considerations dominated objectivity and thus ineffectiveness of the appraisal system.  The main objective of the present study was to assess the effects of personality factors on the effectiveness of employee performance appraisal system in institutions of higher learning in Nakuru County.  The study adopted a survey design.  The study population comprised of all academic personnel in public universities Nakuru County.   A sample size of 224 respondents was selected randomly from a population of 507.  This number was distributed among academic staff across all the departments and sections.  The instrument for collecting data was a questionnaire which was used to collect get both qualitative and quantitative data.  The questionnaire was distributed amongst the all academic staff in public universities in Nakuru County.  A total of 220 out of 224 academic staff completed questionnaires, which represented all public universities in the county with varying demographic backgrounds.  Analysis of quantitative data was done to test hypothesis using the ANOVA and regression analysis.  The results indicated that job related factors (training and development, promotion and tasks in organisation had a positive impact on the effectiveness of employee performance appraisal system among the selected institutions of higher learning in Nakuru County.  An effective performance appraisal system enables organizations realize their goals as well as employees personal growth. Keywords: Employee performance appraisal system and personality

Reward and Compensation as a Determinant of Employee Commitment: A Survey of Ktda Tea Factories in Kenya

The purpose of this study was to investigate the determinants of employee commitment in tea organizations in Kenya. Strong commitment is correlated with high productivity, while low commitment lowers productivity. The primary objective of this research was to determine the influence of reward and compensation on employee commitment in tea factories in Kenya. To achieve this objective a survey was conducted to canvas the opinions of respondents in public KTDA tea factories in Kenya. Purposive sampling was employed to select six (6) factories based on second payment known as bonus; with three (3) high paying and three (3) low paying. Stratified sampling technique was used to categorize population into managers and employees. Random sampling was used to give the sample size of employees. A total of 273 respondents were randomly selected from a population frame of 861 employees. Qualitative and quantitative data was collected by use of self-administered structured questionnaires and interview schedule. Analysis of data showed low paying factories had a lower average mean in all aspects of reward and compensation 54.93% compared to high paying at average mean 71.60%.Further analysis using Spearman’s rank correlation test revealed significant relationship (P=0.00<0.01) between reward and compensation and commitment. The study confirmed the significance of reward and compensation as a determinant of employee commitment. This study has implications for management of KTDA tea factories in Kenya since they can influence employees to achieve optimized motivation and commitment, by designing a good reward and compensation that is perceived as fair, equitable and consistent. Keywords: Reward and Compensation, Employees, Commitment, Organization, Enlisted Factorie

Training as a Determinant of Employee Commitment: A Survey of KTDA Tea Factories in Kenya.

The purpose of this study was to investigate the determinants of employee commitment in tea organizations in Kenya. Observations among 54 enlisted KTDA tea factories in Kenya show high disparity in average payment of tea deliveries (bonus) over a three year period 2009 to 2012. According to Tiampati (2012) strong employee commitment is correlated with high productivity, while low commitment lowers productivity. The primary objective of this research was to determine the influence of training aspects on employee commitment in tea factories in Kenya. To achieve this objective a survey was conducted to canvas the opinions of respondents in public KTDA tea factories in Kenya. Purposive sampling was employed to select six (6) factories based on second payment known as bonus; with three (3) high paying and three (3) low paying. Stratified sampling technique was used to categorize population into managers and employees. Random sampling was used to give the sample size of employees. A total of 273 respondents were randomly selected from a population frame of 861 employees. Qualitative and quantitative data was collected by use of self-administered structured questionnaires and interview schedule. Analysis of data showed low paying factories had a lower average mean in all aspects of training 46.25% compared to high paying at average mean 76.34%.Further analysis using Spearman’s rank correlation test revealed significant relationship (P=0.00<0.01) between training and commitment. It was recommended that training needs should be conducted periodically so as to organize specific training programmes for improving skills, competence and built employee commitment.).The findings of this study will help management with intervention strategies to put in place human resource practices like training that enhance employee commitment to increase efficiency and productivity for better financial gains. Key words: Training, Employees, Commitment, Organization, Enlisted factorie