Browsing by Author "Kamweru, Paul"

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Correlation Between Electromagnetic Wave Equation and Einstein Theory of Relativity in Derivation of Schrödinger Equation and Hilbert Space Operators "
(2020-03) Mbatha, M. Elizabeth; Musundi, Sammy Wabomba; Kamweru, Paul
Operators in Hilbert space have properties which are useful in the study of mathematical abstract areas such as approximation theory, Banach Fixed point theory, the spectral theory as well as Quantum Mechanics. Schrödinger equation is a fundamental entity with many applications in Quantum Mechanics. This equation was initially derived by applying the knowledge of electromagnetic wave function and Einstein theory of relativity. Later, it was derived by applying the knowledge of Newtonian mechanics. It was also derived by extending the wave equation for classical fields to photons and simplified using approximations consistent with generalized non-zero rest mass. However, from the existing literature no study has been done on deriving Schrödinger equation using properties of Hilbert space operators. In this study, Hilbert space operators that include unitary operators, self adjoint operators and compact operators, norms of linear operators, Hilbert Schmidt operator, normal operators together with Lebesque Integral, Neumann Integral and spectrum are used in place of the existing concepts of electromagnetic wave function, Einstein theory of relativity and approximation consistent with generalized non zero mass to derive the Schrödinger equation. The derivation of Schrödinger equation and its application using Hilbert space operators enhances a better understanding of the concept of Schrödinger equation. The results of this work can further find use in quantum mechanics as well as in mathematical operator theory.
Determination Of The Density And The Damping Properties Of Polyethylene (Pe) And Polylactic (Pla) Films Using Dma
(2013-08) Muthui, Zipporah wanjiku; Nderitu, F. Gb; Hussein, S. Ab. Golicha; Ngumbu; Kamweru, Paul; Ngumbu, Richard
Damping which is an effect that tends to reduce the amplitude of oscillations in an oscillatory system is significant in components under high dynamic loads especially in general mechanical engineering. In this study, Dynamic mechanical analysis is used to compare the damping characteristics of Polyethylene (PE) and Polylactic acid (PLA). The DMA 2980 apparatus is used in the Multistrain mode and the recommended combination for a single-frequency temperature ramp of a frequency of 1 Hz and ramp rate of 3 C  per min. PE is a tough, semi-rigid plastic with a high modulus between temperatures of 188 - 409K. The properties of PE can be ‘tuned’ by varying the average length of the molecule chains, making it a very versatile material with a wide range of uses. The benefits conferred on society by the development of PE from fossil fuels have in recent years been obscured by the problem of their ultimate disposal. A suitable alternative has however not been provided. More research and development is being directed towards development of environment friendly materials. Such materials must possess all the mechanical properties of PE and disintegrate within a reasonable time frame leaving no toxic substances or visible traces upon disposal. According to the American society of testing and materials (ASTM D6400-04) and the European standards (EN 13432) a compostable material should biodegrade such that Carbon is converted to Carbon IV  Oxide to the level of 60% and 90% over a period of 180 days. In other words, it should be strong yet biodegradable. These can be manufactured from biopolymers. The introduction of these biopolymers will reduce the consumption of petroleum, which releases carbon dioxide, a greenhouse emission, unburned carbon fragments and other compounds that give rise to smog and air pollution on burning. They are also compostable, aiding solid waste management. PLA is a biopolymer which can be used to manufacture thermoplastic materials. The density of a polymer is a measure of the proportion of crystals within its mass. The crystallinity of a polymer inturn is directly proportional to its modulus which has a direct bearing on its damping properties. In this study the density of PLA was found to be 1249 kg/m3 while that of PE was found to be 920 kg/m3 . PLA is therefore more crystalline than PE. The Loss tangent (tan δ) values at 50 C  and an amplitude of 10 µm was found to be 0.055 for PLA and 0.191 for PE. The damping properties of PE at 50 C  are therefore higher as compared to PLA. Hence, there is a higher dissipation of energy in PE as compared to PLA on the application of a dynamic force at this temperature. The damping characteristics of PE remain fairly constant with time on application of a sinusoidal force while those of PLA increase.
Patient and Health System Related Factors Associated with Non-Adherence to Antihypertensive Medication among Patients at Chuka Referral Hospital, Kenya
(Scientific Research Publishing Inc., 2021-05-08) Gikunda, Charity; Gitonga, Lucy; Kamweru, Paul
Background: Non-adherence to hypertensive medication continues to become a contributing factor to hypertensive complications like stroke, heart attacks, kidney disease heart failure. Associated factors to non-adherence are complex, are both internal and external to the patient and are difficult to extrapolate. Reports from Chuka referral hospital records showed that in 2016 there were 140 patients with hypertensive complications from 560 patients who attended the medical clinic that year. Objective: This study sought to explore the patient’s related factors that are associated with non-adherence to hypertension medication. Methods: This is a descriptive study design of (N = 575) people among them doctors, pharmacists, nurses, record officers and hypertension patients. Simple random sampling for patients (n = 81) and census sampling for health care workers was done and data collected using questionnaires and interview schedules between April 4th-May 30th 2019. Inferential and descriptive statistics were used for data analysis, aided by SPSS version 25. Results: 64% of the patients stated that they had missed medication. A significant negative correlation (rpb = −0.23, p < 0.05) between age and non-adherence, significant positive correlation with monthly income (rpb = 0.24, p < 0.04), non-significant relationship between non-adherence and marital status (rpb = −0.13, p = 0.25) and patients’ level of education (rpb = −0.06, p = 0.57). The overall model of health system related factors were found to be significant (p < 0.05) and this included; quality of health service, physician patient relationship, stock out, health education, and availability of medicine (p = 0.012). Conclusion: Lacks of funds, unavailability of drugs are the leading factors to regimen completion. This could be easily be addressed by the government.
Polylactic acid (PLA) viscoelastic properties and their degradation compared with those of polyethylene
(2015-12) Muthui, Zipporah wanjiku; Kamweru, Paul; Nderitu, F. Gb; Hussein, S. Ab. Golicha; Ngumbu, Richard
Polyethylene (PE) films are widely used in packaging. PE is a thermoplastic manufactured from nonrenewable petroleum resources. Due to its non–biodegradability, its films have posed serious pollution problems e.g. visual pollution, blockage of gutters and drains, choking of animals etc. Suitable replacements for PE films especially for single use only, are the starch based thermoplastics such as Polylactic acid (PLA) which are fully biodegradable. This paper reports a comparison of the viscoelastic properties of commercially obtained PLA and PE films, and the degradation of the same under a composting environment. The storage and loss moduli of PLA and PE films were determined using the Dynamic mechanical analyzer (DMA) model 2980. The elastic modulus of PLA was found to be 2222.87 MPa at 50˚C and amplitude of 10 μm. This is higher than that of PE which was found to be 236.69 MPa at the same temperature and amplitude. Analysis of composting samples over a time span of 36 days indicated a rapid loss of storage modulus of PLA with that of PE remaining fairly constant. Overall, the results suggest that PLA is a suitable substitute for PE in as far as technical performance and degradability is concerned.
Polylactic acid (PLA) viscoelastic properties and their degradation compared with those of polyethylene
(Academic Journals, 2015-10-19) Wanjiku Muthui, Zipporah; Kamweru, Paul; Nderitu F. G; Hussein S. A. Golicha; Ngumbu R.; Njoroge G. N.
Polyethylene (PE) films are widely used in packaging. PE is a thermoplastic manufactured from nonrenewable petroleum resources. Due to its non–biodegradability, its films have posed serious pollution problems e.g. visual pollution, blockage of gutters and drains, choking of animals etc. Suitable replacements for PE films especially for single use only, are the starch based thermoplastics such as Polylactic acid (PLA) which are fully biodegradable. This paper reports a comparison of the viscoelastic properties of commercially obtained PLA and PE films, and the degradation of the same under a composting environment. The storage and loss moduli of PLA and PE films were determined using the Dynamic mechanical analyzer (DMA) model 2980. The elastic modulus of PLA was found to be 2222.87 MPa at 50˚C and amplitude of 10 μm. This is higher than that of PE which was found to be 236.69 MPa at the same temperature and amplitude. Analysis of composting samples over a time span of 36 days indicated a rapid loss of storage modulus of PLA with that of PE remaining fairly constant. Overall, the results suggest that PLA is a suitable substitute for PE in as far as technical performance and degradability is concerned.
TEACHERS’ INFORMATION COMMUNICATION AND TECHNOLOGY PREPAREDNESS FOR IMPLEMENTATION OF COMPETENCY BASED CURRICULUM IN PUBLIC PRIMARY SCHOOLS IN MERU SOUTH SUB COUNTY, KENYA
(CHUKA UNIVERSITY, 2021) Kairo, Catherine; Njagi, Mercy; Kamweru, Paul
Teachers are the implementers of curriculum hence play a significant role in developing and transforming a learner. Teachers’ competencies such as knowledge and skill in the use of digital devices in all areas of the curriculum delivery is crucial in order to make learning more captivating. The purpose of the study was to investigate teachers’ information communication and technology (ICT) preparedness on implementation of the competency-based curriculum. The study was carried out in public primary schools in Meru South Sub County, Kenya and adopted descriptive survey design. The target population was all preschool teachers in the Sub County. Simple random sampling technique was used to sample participating schools and pre-school teachers and head teachers. The sample comprised of 105 respondents, 75 preschool teachers and 30 head teachers. Data was collected using questionnaires and interview schedule. The research findings were analysed both quantitatively and qualitatively. The quantitative data was processed and analysed with the help of the SPSS software version 22 and summarised into frequency tables and percentages. The findings of the study revealed that majority of the teachers had not been exposed to information communication and technology and most of them were not competent as they lacked technological skills. Hence, lack of information communication and technology skills among the teachers may hinder effective implementation of the competency-based curriculum. The study recommend that the Ministry of Education and Kenya Institute of Curriculum Development to organise for in-service training for teachers to adequately equip them with ICT skills and secondly the Ministry of Education should provide adequate ICT facilities ,employ technical support team for repair and maintenance of the ICT facilities and offer ICT technical support to teachers for efficient implementation of competency based curriculum. Keywords: ICT, Preparedness, Implementation, Competency Based Curriculum
UV Absorption and dynamic mechanical analysis of polyethylene films
(2014-12) Kamweru, Paul; Ndiritu, Francis; Kinyanjui, Thomas; Muthui, Zipporah wanjiku; Ngumbu, Richard; Odhiambo, Peter Migunde
Photooxidative processes that lead to chain scission and chain linking in polymers play an important role in polymer degradation. These processes are induced by both ultraviolet (UV) and visible light absorption. The capability of these radiations to be absorbed depends on the existence of chromophores in the polymeric material. Assessment of photodegradation data obtained from a polymer material processed in a conventional manner is of more practical use than extrapolation of data obtained from pure resin. This study reports on the absorption of ultraviolet-light by conventionally processed polyethylene (PE) films. The PE film samples were submitted to UV from fluorescent lamps at 20°C and relative humidity 40% for two hours. Transmission, reflection and emission spectra, from which absorption was inferred, were obtained with anoptical spectrum analyzer. The study also reports the natural degradation under solar action of these PE films for a period of up to 150 days. Degradation was analyzed by change of the storage modulus using a dynamic mechanical analyzer instrument. Evidence of chromophoric sites was inferred from the absorption of UV light in the range 250 to 400 nm. However, the UV absorption was low in this range. The drop of storage modulus up to 150 days, averaged for the range (50 to 98°C), fit well a hypothetical polynomial of order two.