Effects of jet algorithms from higher order QCD in W±W^\pm mass determinations at LEP2

We analyse the impact of systematic effects due to the scale dependence of QCD corrections in combination with the use of different jet clustering algorithms in the measurement of the $W^\pm$ mass in the fully hadronic decay mode of $W^+W^-$ pairs produced at LEP2. We consider higher order contributions induced by both virtual and real gluon radiation onto the electroweak CC03 and CC11 channels through ${\cal O}(\alpha_{s})$ at the parton level. We find that the associated uncertainties can be of order 100 MeV, thus competitive with those possibly arising in the non-perturbative regime and indeed above the current experimental estimates.Comment: 16 pages, latex, 4 figures, version to appear in EPJdirect

Consumer Ethnocentrism, Demographic Characteristics and Willingness to Buy Commercial Banking Services in Kenya

International marketing empirical literature has indicated the existence and strength of relationships among the consumer ethnocentrism, demographic variables and product attitude vary in different market context. Subsequently consumer ethnocentrism and purchase intentions influence depends on the product categories and other market factors. It is on the basis of this premise that the current study embarked on assessing the moderating effect of demographic characteristics on the relationship between consumer ethnocentrism and willingness to buy banking services. Descriptive and explanatory research design were used in the study. Primary data was collected among 374 commercial banks account holders in Kenya. Data was analyzed using step wise binary logit regression. Consumer national ethnocentrism was found to have a negative influence on the willingness to buy banking services from foreign owned commercial banks. The assessment of the effect of demographic characteristics on willingness to buy commercial banking services revealed that as the levels of respondents’ income per month increased, there was high preference of buying from foreign owned banks and vice versa. However age, gender and income do not moderate the relationship between consumer ethnocentrism and willingness to buy banking services. This indicate the essence of intergroup differentiation in service or market offerings as well as market segmentation and targeting

Vulnerabilities Facing Digital Content at the University of Nairobi and Catholic University of Eastern Africa Academic Libraries

An academic library is a library that is attached to a higher education institution and serves two complementary purposes: to support the curriculum, and to support research by university faculty and students. Increasingly, these very sacrosanct information centres to the University mandate are faced with security threats on digital content. These threats include but are not limited to computer-assisted fraud, espionage, sabotage and vandalism. The study objective of this study was to examine the vulnerabilities facing digital content at the University of Nairobi and Catholic University of Eastern Africa academic libraries. The study employed a descriptive survey design. The target population in this study were 2 Information and Communications Technology Managers and 10 ICT technicians, 2 Chief Librarian and 20 Library Staff. The study had a target population of 34 respondents. A census was used to arrive at a sample of 34 respondents from the two university academic libraries. Data was collected by use of semi-structured questionnaires, with both closed and open ended questions. The quantitative data analysis was conducted using descriptive statistics to obtain frequencies and percentages. The key findings of the study are that the university lack proper disaster management on digital content information materials. There is Lack of reliable infrastructure and resources in the library, lack of enough funding and sometimes delayed provision of funds for procurement of necessary computing equipment thus hindering the establishment of disaster recovery centres, lack of programmes to guide on training and training needs, unclear policies and guidelines in the University. The study provides several recommendations that would improve the current state of disaster planning and preparedness. The university should train and retrain its core staff to ensure that they are updated with current knowledge and skills that focuses on ever changing security threats to digital security and preparedness. The institutions management should give provision of adequate funds for continuous training. The institution should have policies to guide on passwords, privileges and have disaster recovery procedure and universities should explore more methods of ensuring Security of digital contents. Keywords: Academic libraries, Vulnerabilities, Digital content, University of Nairobi, Catholic University of Eastern Africa DOI: 10.7176/IKM/11-4-02 Publication date:May 31st 202

Factors associated with pneumonia in children under five (2-59 months) in Nairobi, Kenya

Introduction: Pneumonia the leading cause of mortality and morbidity in children under five in the world. Most deaths occur in Sub-Saharan Africa and South Asia. Objective: This study investigated factors associated with pneumonia at their first presentation in Mbagathi District Hospital, Nairobi County. Methods: We conducted a hospital based cross-sectional study at the pediatric department at Mbagathi District Hospital. All guardians of children between 2-59 months were recruited at the hospital causality and inpatient department. Pneumonia diagnosis was based on WHO definitions. Pneumonia was associated with fast breathing with or without chest in drawing. Severe pneumonia was defined as fast breathing with any danger signs. Systematic random sampling procedure was used to select study participants. A total of 384 guardians together with their children were sampled. Results: Childhood pneumonia was caused by a combination of exposure to risk factors related to the host, the environment and infection. Low level of education of guardians was associated with pneumonia in children p<0.0.5 (Wald= 8.358, df =3). Crowding was associated with pneumonia in children p<0.05 (OR 0.33, 95% CI, 0.11-0.95). Birth weight of children was significantly associated with pneumonia p<0.05 (OR 0.59, 95% CI 0.38-0.92). Conclusions: The prevalence of pneumonia in children is reducing, this due to the public health interventions in the households and the hospital facility. Poor environmental factors increase the suffering of the community and this makes it difficult to prevent and control pneumonia. Increased pneumococcal conjugate vaccine coverage in children could significantly reduce the burden of pneumonia in sub-Saharan African countries. Key words: Childhood pneumonia, streptococcus pneumoniae, under five (2-59 months), Acute lower Respiratory Infection (ALRI)

External root morphology of maxillary first premolars in Kenyan Africans

Objective: To determine the external root morphology of the maxillary first premolarsin Kenyan Africans.Design: In vitro descriptive cross-sectional study.Setting: School of Dental Sciences, University of Nairobi.Subjects: One hundred and fifty five extracted maxillary first premolar teeth obtainedfrom patients aged between 13-30 years attending dental clinics within Nairobi.Main outcome measures: Number of roots, direction of root curvature and toothlength.Results: A total of 155 maxillary first premolars were studied, 77 from males and 78from females. Overall, there were 83.2% two-rooted teeth (mean tooth length: buccalroot 22.3 mm; lingual root 21.2 mm), 10.3% one-rooted (mean tooth length-22.6 mm)and 6.5% three-rooted. Three roots occurred more commonly in males than femalesand this was a statistically significant gender difference (P<0.05). Males were foundto have larger mean tooth length than females in multirooted teeth. Majority of theroots were straight (57.2%). Distal and “S” curvatures were the commonest (19.1% and10.2% respectively). There were no significant gender differences in direction of rootcurvature (P>0.05).Conclusions: Maxillary first premolars were mostly two-rooted with straight roots.Males presented with two or three roots more often than females and had significantlylarger mean tooth lengths

Design and Experimental Testing of a Solar Box Cooker with Paraffin Wax as Thermal Energy Storage Using Maiduguri Weather Condition

The performance of paraffin wax as phase change material (PCM) for thermal energy storage (TES) was investigated using a Solar Box Cooker (SBC) exposed to Maiduguri weather condition. Temperature and energy generated by SBC were experimentally established. The result shows tremendous improvement in energy storage compared to SBCs without TES in existence within Maiduguri and environs. The measured temperature and energy generated by the PCM in the experiment were 118oC and 4164.5KJ respectively, an adequate temperature and energy for cooking during off-sunshine hours and beyond. First figure of merit (F1) and second figure of merit (F2) were deduced to be 0.13 and 0.44 with overall SBC efficiency (ɳ) of 63% qualifying the SBC to grade A based on the Bureau of Indian Standards (BIS

Kinetic modeling of ethylbenzene isomerization using Bodenstein approximation technique

Ethylbenzene isomerization reaction is a significant reaction employed in the production of xylene isomers which are used as petrochemical feedstocks. The reaction which proceeds over Pt/Al2O3 catalyst is multi-pathway and multi-cycle in topology. Kinetic model for the reaction was developed in this study using the general rate equation approach. Bodenstein approximation, cross-to-square, and Y-to-delta transformation techniques were used to reduce the complex reaction network to a single cycle network. In addition, the general rate equation for reduced single cycle networks was applied to derive the model for the reaction. The Nelder-Mead simplex optimization technique was used to estimate the kinetic parameters in the model. The structure of the model developed indicates that the model reasonably represents the mechanism of the reaction although few anomalies were observed in the values of the kinetic parameters estimated. The activation energy obtained for the rate constants follows the expected trend for multi-step reactions

Application of Stearic Acid for Solar Thermal Energy Storage in a Double Compartment Solar Box Cooker

Energy storage in some form is the need of the hour to even out the mismatch between energy supply and demand. Thermal Energy Storage (TES) system employing a phase change material (PCM) has been widely considered as an effective way to store and retrieve energy due to its high heat storage capacity at almost constant temperature during the phase change. In this work, an energy storage system was designed to study the heat transfer characteristics of stearic acid (as a phase change material in a double compartment solar box cooker (DCSBC) fabricated using wooden materials with high thermal energy storage system. In order to analyze the various characteristics of the PCM, the Bureau of Indian Standards (BIS) was used throughout the experiment. Investigations were performed to determine the first and second figure of merits (F1 and F2) of compartments 1 and 2 (C1 and C2) simultaneously. The results for F1 were found to be (C1= 0.14 and C2= 0.15) and F2 were (C1=0.47 and C2= 0.4) while the overall thermal efficiency of the cooker after water boiling test for C1 with 2.5kg and C2 with 3kg of water were deduced to be 77% for C1 and 92% for C2 after six hours of the load test, showing considerable temperature increase and extension of heat retention making possible to cook the dinner and even breakfast the next day