Browsing by Author "Kamweru Kuria, Paul"

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Calorific Value and Moisture Content Of Selected Solid Wastes at Chuka University
(IJRP.ORG., 2020-04-02) Kanogo Thuo, Daniel; Kamweru Kuria, Paul
Solid waste, which typically consists of metals, plastics, glasses, paper, wood, and organics, is generated and accumulated due to human day to day activities. The waste often leads to ecological pollution unless an appropriate solid waste management system is applied. Remarkably, solid waste can be channeled into a very useful form to generate energy leading to the reduction of the use of fossils fuels which are rapidly becoming limited, reduction of wastes in dumping sites and also be an additional source of energy. For such ventures though, the amount of energy that can be recovered from burning solid waste needs to be determined. In this work, solid waste samples were collected, classified, sundried, powdered and sieved using a sieve of size 500µm. The percentage moisture content of fruits waste, animal dung, and yard trimming & vegetables were found to be 33, 48, and 55 % respectively. The fruits waste had the highest calorific value of 104,130.91J/g, followed by the animal dung with 95,804.13 J/g and the least was yard trimming and vegetables with 95,100.39 J/g. The average specific energy content is 98345.14 J/g.
Food Rheology using Dynamic Mechanical Analysis; A short review
(Paul Kamweru, 2020-02) Kamweru Kuria, Paul
An ideal elastic material will deform finitely and recover its original shape and size upon the removal of the applied deforming load. On the other hand an ideal fluid will deform and continue to deform as long as the deforming load is applied, and finally the material doesn’t recover from that deformation even when the load is removed. These two responses are termed as ‘elastic’ and ‘viscous’ respectively. Most materials, exhibits an intermediate viscous and elastic behavior and are referred to as “viscoelastic”. A good example of such materials are polymers. In addition almost all foods, both liquid and solid, belong to this group. The viscoelasticity of materials can be determined by transient or dynamic methods. The transient methods are two pronged; stress relaxation which is the application of constant and instantaneous strain and measuring decaying stress with respect to time and creep which is the application of constant and instantaneous stress and measuring increasing strain with time. The transient methods are easy to perform, however, they are limited in the sense that the material response cannot be determined as a function of frequency. The dynamic methods are performed applying a small sinusoidal strain (or stress) and measuring the resulting stress (or strain). Due to the enormous list of advantages of performing dynamic tests, the method has been very popular in polymer studies for many years. This brief review demonstrates that the method has found a now increasing usage, especially in the last two decades, in studies of food, what has been referred to as Food Rheology.
Thermal Conductivities of Selected Solid Waste Materials Determined Using Lees’ Disc Method
(International Journal of Research Publications (IJRP.ORG), 2020-04-02) Chepkorir, Doreen; Kamweru Kuria, Paul
In this study, the coefficients of thermal conductivities have been determined. The goal was to find out the best insulator among the recyclable and locally available materials which can be adopted for use to replace the existing thermal insulation. Rice husks, dry grass, sawdust and old/used newspapers have been studied in this study using Lees’ disc method. The results showed that grass can do best as an insulating material though all the samples can be used as insulators. They all have low thermal conductivities. The coefficient of thermal conductivities ranged from 𝟎. 𝟐𝟐𝟔 𝑾/𝒎𝑲 for grass, 𝟎. 𝟐𝟕 𝑾/𝒎𝑲 for saw dust, 𝟎. 𝟓𝟎 𝑾/𝒎𝑲 for rice husks and 𝟏. 𝟗𝟑 𝑾/𝒎𝑲 for newspaper cut-outs. Due to their local abundance, and no much competing commercial interest, we recommend the studied materials as suitable thermal insulators.