JKUAT Annual Scientific Conference

Performance evaluation of a scoria evaporative cooler for storage of mango fruits

2025-04-07T09:43:59Z

Performance evaluation of a scoria evaporative cooler for storage of mango fruits Mokaya, Peter N. The scoria evaporative cooler designed for this project applies the principle of evaporative cooling to reduce the temperature while at the same time increasing relative humidity inside the storage chamber. The modern preservation systems such as refrigerators are out of reach to most farmers; in-terms of cost and electricity which is costly and inappropriate for remote areas without electricity. The design consists of a cabinet box type whose dimensions of length, width, and height were 1000mm, 1000mm, and 1400mm, respectively. The performance of the scoria evaporative cooler was evaluated by monitoring the vitamin C, the weight, total soluble solutes, and firmness of the mango fruits and also the temperature and relative humidity throughout the study period. Mature and green apple mangoes were sourced directly from a farm in Tala Machakos County. Three labelled mangoes were randomly selected for evaluation of physiological weight and peel colour changes during storage and subsequent evaluation was repeated on the same fruits. The measurement of firmness, vitamin C and total soluble solids which involved destruction of fruits, the fruits were randomly selected, evaluated and discarded. The shelf-life and quality attributes (viz., physiological weight, firmness, TSS, and vitamin C) of the fruit stored in the cooler were evaluated against the fruits stored under ambient conditions. The temperature and relative humidity of storage environment for the cooler was of average value of 19.27 oC and 88.88% whilst the ambient storage were on average 30.41 oC and 35.28% respectively. Thus, the cooler lowered the storage temperature by 11.14 oC as compared to ambient conditions. This technology extended the shelf life of the apple mangoes by ten days as compared to storage under ambient conditions and this also preserved the quality of the fruit thereby reducing the losses and hence will make mango farming more profitable. Scientific, Technological and Industrialization Conference

Experimental investigation on performance of a compression ignition engine fueled with waste cooking oil biodiesel–diesel blend enhanced with Iron-doped Cerium Oxide nanoparticles

2021-03-08T08:18:50Z

Experimental investigation on performance of a compression ignition engine fueled with waste cooking oil biodiesel–diesel blend enhanced with Iron-doped Cerium Oxide nanoparticles Meshack Hawi, Ahmed Elwardany, Mohamed Ismail and Mahmoud Ahmed The effect of iron-doped cerium oxide (FeCeO2) nanoparticles as a fuel additive was experimentally investigated with waste cooking oil methyl ester (WCOME) in a four-stroke, single cylinder, direct injectiondiesel engine. The study aimed at the reduction of harmful emissions of diesel engines including oxides of nitrogen (NOx) and soot. Two types of nanoparticles were used: cerium oxide doped with 10% iron and cerium oxide doped with 20% iron, to further investigate the influence of the doping level on the nanoparticle activity. The nanoparticles were dispersed in the tested fuels at a dosage of 90 ppm with the aid of an ultrasonic homogenizer. Tests were conducted at a constant engine speed of 2000 rpm and varying loads (from 0 to 12 N.m) with neat diesel (D100) and biodiesel–diesel blends of 30% WCOME and 70% diesel by volume (B30). The engine combustion, performance, and emission characteristics for the fuel blends with nanoparticles were compared with neatdiesel as the base fuel. The test results showed improvement in the peak cylinder pressure by approximately 3.5% with addition of nanoparticles to the fuel. A reduction in NOx emissions by up to 15.7% were recorded, while there was no noticeable change inunburned hydrocarbon (HC) emissions. Carbon monoxide (CO) emission was reduced by up to 24.6% for B30 and 15.4% for B30 with nano-additives. Better engine performance was recorded for B30 with 20% FeCeO2 as compared to 10% FeCeO2, in regard to cylinder pressure and emissions. The brake specific fuel consumption was lower for the fuel blend of B30 with 10% FeCeO2 nanoparticles, in low-to-medium loads and comparable to D100 at high loads. Hence, a higher brake thermal efficiency was recorded for the blend inlow-to-medium loads compared to D100.

Use of the Outdoor Range and Activities of Rhode Island Red Hens Grazing on Natural Vegetation in the Tropics

2018-02-12T08:59:17Z

Use of the Outdoor Range and Activities of Rhode Island Red Hens Grazing on Natural Vegetation in the Tropics Abouelezz 1, F. M. K. 2; Franco1, L. Sarmiento; Ricalde1, R. Santos-; Correa1, J. Segura The aim of this study was to investigate the range utilization of Rhode Island Red hens, grazing outdoor (under tropical conditions) and to scan their activities inside the house as well as during their outdoor visits. The activities of RIR hens, raised in indoor floor pens connected with outdoor areas covered with natural vegetation, were scanned and recorded individually within 15 minute intervals between 08:00 and 17:00 hours (37 scans a day) for a duration of twelve weeks. The results revealed that, 40.5% of the hens were observed to be on the range at each scanning time; where they engaged their outdoor visits in foraging (11.4%), exploring (8.62%), roaming (6.1%), standing (3.5%), primping (5.6%) and resting (5.4%). Besides, the utilization of the closest part of the range to the house was significantly the highest in comparison with the middle and farthest parts (73.0 vs. 24.9 and 2.1%, respectively), and the highest (P< 0.05) average utilization of the range was recorded during the early day hours, versus the midday and late day hours. In total, 24 meters apart from the house forms the most adequate distance for free range RIR hens while longer distances would rarely be visited. The grazing RIR hens (in the tropics) utilized the outdoor area effectively and performed natural behavior. Keywords

Efficiency and Sustainability of Silage Corn Production by Data Envelopment Analysis and Multi-Functional Ecological Footprint: Evidence from Sarayan County, Iran

2018-02-12T08:17:59Z

Efficiency and Sustainability of Silage Corn Production by Data Envelopment Analysis and Multi-Functional Ecological Footprint: Evidence from Sarayan County, Iran . Dourandish, A; Saadi, H; Mahdei, v K. Naderi; Esfahani, S. M. J. The Ecological Footprint (EF) is used to understand the relationship between human activities and pressure on land and its resources. The present study combined multifunctional ecological footprint with Data Envelopment Analysis (DEA) to estimate environmental impacts of inefficient use of resources of silage corn production in the Sarayan County, Iran. In this applied survey research, data were collected using a questionnaire accompanied by face-to-face interviews with 42 farmers (N= 48). Validity of the instrument was approved by a panel of experts; while its reliability was secured via pretest-posttest method. Results showed that mean technical efficiency, pure technical efficiency and scale efficiency were 0.86, 0.93, and 0.80; respectively. The CO2 footprints were 0.95 and 0.83 gha under current and optimum conditions; respectively, with electricity and manure comprising the highest and lowest shares. The Ecological footprint land- (gha gha-1 farm), yield- (gha ton-1) and revenue-based (gha $-1 1,000) EFs were estimated to be 1.6, 0.84, and 1.4 under current conditions but 1.57, 0.081, and 1.33 under optimum conditions, respectively. When the resources were used efficiently, the EFCO2 and EF improved by 13.42 and 3.35% respectively, in which the highest shares in terms of quantity and percentage belonged to electricity, manure and fertilizer. Findings implied that optimum usage of electricity and fertilizer could play a significant role in mitigating environmental impacts of silage corn production in Sarayan. Local agricultural extension should focus on introduction of innovative irrigation systems to reduce water, electricity and fertilizer consumption. Meanwhile, to improve silage corn efficiency, farm size expansion is recommended based on the DEA findings. Keywords