EXPERIMENTAL INVESTIGATION OF THE POTENTIAL OF LIQUIFIED PETROLEUM GAS IN VAPOUR COMPRESSION REFRIGERATION SYSTEM

The essence of refrigeration systems cannot be overemphasized especially in this part of the globe. Perishable items are to be preserved for some periods before usage while human comfort should also be also be paramount since we are in the northern hemisphere of the globe. The device hat doe this uses refrigerants as working fluids which are traditional harmful to human beings through depletion of the ozone layer. Majorly Ozone layer protects the earth from warming which could lead to flooding. Common economical refrigerants like CFCs (Chlorofluorocarbons) have been discovered to be harmful to the earth. This article therefore, experimented the quantity replacement of CFCs with Liquefied Petroleum Gas in various mixes. The LPG (Liquefied Petroleum Gas) used consists a mixture of propane and butane in the ratio 6:4 by mass. The blend of the two refrigerants were shaped essentially by blending at least two single-part refrigerants, the GWP (Global Warming Potentials) of a refrigerant mix is the mass-weighted normal of GWPs of individual parts in the mix. That is, to compute the GWP of a mix, one essentially adds the GWP of the singular parts with respect to their (GWP (LPG) x M (LPG)) + (GWP(R-134a) x M(R-134a)) = GWP (blend). From the evaluated GWP of the 6 different % mass composition, the % mass of (100%/0%) was the only refrigerant to adhere to the preferred GWP<150. The mass composition of blend (100%/0%) LPG/R-134a was first performed. In-order to achieve this, 8kg of each of the refrigerant was used. The blend was formed in an empty cylinder which was measured as 2482g with the aid of a digital beam balance, by gradually injecting LPG into the empty cylinder till the mass percentage of the 2000g entered, making the mass read as 4,482g (i.e., 2482g of the empty cylinder + 2000g of LPG). Based on the above observations, it could be inferred that the COP (Coefficient of Performance) of mixed refrigerants blends was higher than that of R-134a indicating that each of the blend exhibit higher performance. The experiment discovered that LPG could be used in the place of R134a without affecting the operation efficiency of a vapor compression refrigeration system. The study concludes that LPG offers the best alternative when the COP and flammability are combined as performance metric

Modeling of Solar Drying Economics Using Life Cycle Savings (L.C.S) Method

Major goals of industrialization include but are not limited to provision of employment, establishing a platform for overall national development and improving the capital income of whoever is involved, which invariably improve the overall standard of living. A better pre-visibility study must encompass a well analyzed economic appraisal of the plan. The law of mass conservation was applied to develop computer software with a view to analyzing the major preliminary economic indexes of industrial solar drying in both developed and rapidly developing economy. The present work used the life cycle cost method to investigate the solar process economics. In the paper three major geographical locations in Nigeria (i.e. Ibadan, Kano and Port Harcourt) were selected and their respective economic appraisal was investigated. Sample simulations revealed that, at a realistic initial moisture content of 30 (% wet basis) of the agricultural produce, economic analysis of over 20 years shows that recommended solar collector area of 85.46 m2, 80.71 m2 and 75.96 m2 supplied about 67%, 88% and 55.8% of the annual energy needed for Ibadan, Kano and Port-Harcourt respectivel

Effect of Building Orientation on Energy Conservation

Nigeria today faces serious challenge in providing adequate energy to meet the needs of her citizenry. Efforts are currently geared towards generation of more energy to ease the problem. While these efforts are commendable, it is equally desirable to explore ways of minimizing consumption of generated energy. This work has thus examined the impact of building orientation on the energy demand and thus proffers its appropriate orientation. A survey was carried out in lbadan which is the largest metropolis city in West Africa. The orientation of built houses in various setting such as Government Reserved Areas, Public/Commercial settings and local dweller settings were studied to determine their conformity with expected standard of North-South orientation of the building length. From the study it was observed that a sizeable percentage of the buildings with the survey were placed longitudinally in the East-West direction implying that more energy may have to be expended in cooling inside the building. The defaults are more pronounced in the local dwellers. In many of the cases considered in this study, the defaults were enhanced by the road networks. This study established the need for more education on building orientation as well as road network planning. This will cut down energy consumption in cooling inside a building

Economic Appraisal Of Industrial Solar Drying (Part I)

Major goals of industrialization include but not limited to provision of employment, establishing a platform for overall national development and improving the monetary income of whoever is involved which invariably improves the standard of living. A better pre-visibility study must encompass a well analysed economic appraisal of the plan. Computer programme was generated to analyse the economic aspect of industrial solar drying. The appraisal was carried out with the software using the Life Cycle Savings (LCS) technique. Three locations in Nigeria (i.e. Ibadan, Kano and Port Harcourt) were selected and their respective economic appraisal simulated. Sample simulations reveal that at a realistic initial moisture content of 30% (% wet basis) of the agricultural produce, economic analysis of over 20 years reveal that recommended solar collector area of 85.46m2, 80.71m2 and 75.96m2 supplied about 67%, 88% and 55.8% of the annual energy needed for Ibadan, Kano and Port-harcourt respectively which are the specific sizes at which life cycle solar savings are optima

The Lake CHAd Deep DRILLing project (CHADRILL) - targeting ~ 10 million years of environmental and climate change in Africa

At present, Lake Chad ( ~13°0 N, ~14° E) is a shallow freshwater lake located in the Sahel/Sahara region of central northern Africa. The lake is primarily fed by the Chari-Logone river system draining a ~600 000 km2 watershed in tropical Africa. Discharge is strongly controlled by the annual passage of the intertropical convergence zone (ITCZ) and monsoon circulation leading to a peak in rainfall during boreal summer. During recent decades, a large number of studies have been carried out in the Lake Chad Basin (LCB). They have mostly focused on a patchwork of exposed lake sediments and outcrops once inhabited by early hominids. A dataset generated from a 673m long geotechnical borehole drilled in 1973, along with outcrop and seismic reflection studies, reveal several hundred metres of Miocene-Pleistocene lacustrine deposits. CHADRILL aims to recover a sedimentary core spanning the Miocene-Pleistocene sediment succession of Lake Chad through deep drilling. This record will provide significant insights into the modulation of orbitally forced changes in northern African hydroclimate under different climate boundary conditions such as high CO2 and absence of Northern Hemisphere ice sheets. These investigations will also help unravel both the age and the origin of the lake and its current desert surrounding. The LCB is very rich in early hominid fossils (Australopithecus bahrelghazali; Sahelanthropus tchadensis) of Late Miocene age. Thus, retrieving a sediment core from this basin will provide the most continuous climatic and environmental record with which to compare hominid migrations across northern Africa and has major implications for understanding human evolution. Furthermore, due to its dramatic and episodically changing water levels and associated depositional modes, Lake Chad's sediments resemble maybe an analogue for lake systems that were once present on Mars. Consequently, the study of the subsurface biosphere contained in these sediments has the potential to shed light on microbial biodiversity present in this type of depositional environment. We propose to drill a total of ~1800m of poorly to semi-consolidated lacustrine, fluvial, and eolian sediments down to bedrock at a single on-shore site close to the shoreline of present-day Lake Chad. We propose to locate our drilling operations on-shore close to the site where the geotechnical Bol borehole (13°280 N, 14°440 E) was drilled in 1973. This is for two main reasons: (1) nowhere else in the Chad Basin do we have such detailed information about the lithologies to be drilled; and (2) the Bol site is close to the depocentre of the Chad Basin and therefore likely to provide the stratigraphically most continuous sequence

The Epidemiology of War and Its Impact on Public Health: A Case Study of the Ukraine-Russia Crisis

Aims: The aim of this article is to provide a concise and comprehensive overview of some of the environmental and public health problems resulting from the Russia-Ukraine war. Methods: This paper adopted a desk review of existing information available from peer-reviewed articles, scientific reports, and grey literature through triangulation of data sources. Findings: Just sixteen months into the face-off, the crisis has been characterised by diverse public health challenges such as environmental-induced pollution; nuclear and technological threat; energy crisis; food insecurity; humanitarian castatropic; and likehood of a surge in COVID-19 and other infectious diseases. The escalation of conflict in Ukraine has caused civilian casualities, forcing people to flee their homes seeking safety and protection. So far, it is estimated that 9,083 civilians have been killed and 15,779 injured in Ukraine; with over 18 millions refugees diplayed within and outside Ukraine as of 19th June, 2023. furthermore, the war has notably triggered food price spike, economic pressure and social stress in most part of Africa, with the inclination to precipitate political upheaval especially in volatile countries in the continent. Conclusion: We opined that prompt attention should be given by international bodies and humanitarian agencies to restore public health sanity in Ukraine by provision of critical protection services and humanitarian assistance. Conclusively, a cease fire by the belligerent nations remain the only panacea to the highlighted problem

DEVELOPMENT AND PERFORMANCE EVALUATION OF GREEN -VEGETABLES SLICING MACHINE

Requirements of food processing units are sensitive and must be in conformity with hygiene and time requirement. Continuous work on the development of machines that are involved in the processing of edibles should be carried out. Traditionally, green-vegetables are plucked raw which often require time and also compromise hygiene. However, the several works done on green-vegetable slicing equipment have added improvement to ways by processing and or consumption. This article attempted the development of green-vegetable slicing machine and also evaluated the performance of same. Existing vegetable slicing machines were studied through literature and process design for development was carried out. Cutting capacity of 1.5 kg and 25 g of uniform slicing were used to evaluate the performance of the developed green-vegetable slicing machine. The shortcomings in the existing slicing machines reduced while reducing loss of sliced and also with uniform slices. Existing vegetable machines has experienced loss and associated time. The developed machine has a significantly improved efficiency to 96%. &nbsp

Modelling the Safety Level of the Construction Industry in Southwestern Nigeria

  The number of accidents in the construction industry in Nigeria is very high. It is rare to disclose safety performance metrics required to draw government attention to these incidents. This research aims to develop a predictive safety analytical model for the construction industry's safety assessment. The activities of safety standards in the Nigerian construction industry and improvement programs expected to be introduced in the construction industry have been researched to recognize the risks of construction accidents. The building injury risks found were modelled as predictor variables while the response variable was the level of safety using multiple regression analysis. Spearman's Correlation Analysis identified predictor variables that correlate significantly at p˃0.05 to the safety level, while predictor variables with low correlations have been excluded. The safety level was calculated on a linguistic scale of 5 points. The predictive ability of the model was verified at a 5 percent significance range by the coefficient of determination (R2) and the t-test. Under Law and Regulation, Practices, Personal Factors and Encouragement, fifteen task-related construction accident risks were identified and listed. The developed multilinear regression model has an 84.8% R2 rating. A 92.1% correlation between the predicted values and the human-interpreted safety-level values was revealed by the model implementation. The study also shows that personal variables should be given the highest degree of consideration by site engineers. The t-test showed no substantial difference between the values predicted and the values perceived by the level of human protection. Due to the feasibility of the study, the constructed model will serve as a valuable instrument for monitoring the safety level of Nigeria's construction sites. It is recommended that the model be used by site Engineers and Safety personnel from Federal and State Ministries.       &nbsp

AN IOT BASED WEATHER STATION USING AN EMBEDDED SYSTEM

© 2022, Emerald Publishing Limited. This is an open access article under the CC BY-NC-ND licence. https://creativecommons.org/licenses/by-nc-nd/4.0/This paper is about the development of an internet-based weather station system to monitor temperature, humidity, light intensity and predict the possibility of whether it will rain or not. The realtime monitoring system was connected to a microcontroller embedded with a Wi-Fi module (NodeMCU/ESP8266), a temperature and humidity sensor (DHT 11), and a light-dependent resistor (LDR). This device is designed as a platform to provide adequate information for immediate and future weather forecasts. The measured parameters are sent to an open-source IoT analytics platform (ThingSpeak), recorded in the channel, and were downloaded for analysis purposes. The temperature and humidity level were monitored using the Things View Android application and can be accessed by anybody once given the Thing Speak channel ID. Weather data was easily viewed and it can aid in appropriate planning. This IoT-based system will help keep up with the demand of the ravaging global warming with the provision of real-time data for planning towards land preparation and crop planting and for other purposes that are weather dependent.Peer reviewe