Journal of Scientific Research and Reports

Thermoelectric devices use the Peltier effect which creates a heat flux between the junctions of two different types of materials. The thermoelectric module also referred to as a heat pump transfers heat from one side to the other when a DC current is applied.

This study carried out the theoretical and experimental analysis of a thermoelectric air conditioning system. A prototype thermoelectric air conditioner of 286 W cooling capacity was built and a testing enclosure made from plywood and Styrofoam was also constructed in order to validate the theoretical result with an experimentation. It was discovered that thermoelectric air conditioning took 4 minutes to reach its desired temperature of 22℃ whereas the standard air conditioning system (Refrigeration Cycle) took 20 minutes to cool to a room temperature. Economically it was also discovered that thermoelectric air conditioning system is 50% cheaper than the refrigeration cycle air conditioning systems.

The thermoelectric air conditioner has cheaper maintenance and greater estimated life span of 7 years more than the refrigeration air conditioner. This is because the air conditioner that operates on the refrigeration cycle uses a rotating compressor while the thermoelectric air conditioner uses thermometric module.

Aims: To use a simulation base exploration to carry out 6 scenarios of green roof construction methods to determine the most efficient in improving indoor thermal comfort.

Study Design: Simulation Design was used as the study design.

Place and Duration of Study: The study was conducted at the Department of Horticulture – Kwame Nkrumah University of Science and Technology located at Kumasi-Ghana between 2016 and 2019.

Methodology: A simulation experimental setup was done to run for 1 year to cover the two seasons in Ghana. Version 5.0.2 Design Builder and Energy Plus 5.8 was used to work on 6 scenarios using leaf area indexes (LAI) of 2 and 5 as well as soil depth (thickness) of (70-150 mm), 200 mm, 300 mm and 500 mm. Also a real life experiment was done at the Department of Horticulture by constructing 9 test cells and using treatments such as Portulaca grandiflora and Setcreasea purpurea to validate the results for the simulation. The time setup for the simulation was from 12.00 am to 11.59 pm.

Results: A leaf area indexes (LAI) of 5 and soil depth of 70 mm-150 mm recorded the lowest simulated temperature ranging from 26.26°C to 29.30°C for scenario one. For scenario two, a leaf area indexes (LAI) of 5 and a soil depth of 200mm recorded the lowest significantly (P≤0.05) indoor temperature in August (26.20°C) and the highest (29.26°C) in March. In February, June and August, significant differences (P≤0.05) were achieved by leaf area indexes (LAI) 5 and soil thickness 500 mm for scenario three. January, March to July indicated significant differences (P≤0.05) between the treatments leaf area indexes (LAI) 2 and soil thickness 300 mm and leaf area indexes (LAI) 5 and soil depth of 300 mm recorded 26.32°C to 29.33°C for August and March respectively for scenario four. A soil depth of 500 mm and leaf area indexes (LAI) of 2 gave significantly (P≤0.05) low temperatures indoors all year (26.27 to 29.32°C) for scenario five and in August leaf area indexes (LAI) 5 and soil thickness of 500 mm recorded the least temperature all year for scenario six.

Conclusion: From the exploration, a soil depth of 70 mm – 150 mm and a LAI of 5, LAI of 5 and soil depth of 200 mm and LAI of 2 and soil depth of 500 mm achieved the lowest temperature and performed better in terms of temperature reduction which will lead to thermal comfort of occupants.

Aims: To analyze the importance and performance rate of various ecotourism component based on visitor perspectives in Helena sky bridge.

Study Design: Interview method.

Place and Duration of Study: October 2018 in Helena sky bridge, Bantimurung Bulusaraung National Park, Maros District, South Sulawesi Province, Indonesia.

Methodology: The interview method, by using prepared structured questionnaire with close ended questions, applied on 50 respondents selected through quoted accidental sampling technique. There were 33 ecotourism subcomponents assessed based on Likert scale. Obtained data processed by the Importance-Performance Analysis (IPA) and displayed in Cartesian diagram.

Results: There was variation of respondent characteristics in term of gender, age, number of visits, visiting purpose and domicile. However, most visitor was young people (18-28 years old) and come from Makassar. The highest performance rate was found on panorama, while the lowest performance rate was homestay. For the importance, the highest score was showed by 3 subcomponents, namely service, skill and garbage dump, while the lowest one was festival. In average, the performance rate of all subcomponents was 2.70 (moderate), while the importance was 3.93 (good). There was a gap between performance and importance that need proper management actions. Development effort should be concentrated in 7 subcomponents plotted in 1^st quadrant, such as the easiness access to get transportation, guide and interpreter, public lavatory, garbage dump, health facility, shopping facility, and clean water availability. 13 subcomponents had already in a good performance, mostly from natural attraction. 10 subcomponents were classed into 3^rd quadrant with low priority management strategy. Moreover, 3 subcomponents (cultural landscape, local peoples’ daily life and hospitality) were in 4^th quadrant with possible overkill situation.

Conclusion: Ecotourism subcomponents such as the easiness access to get transportation, guide and interpreter, public lavatory, garbage dump, health facility, shopping facility, and clean water availability should be prioritized.

With the continuous introduction of policy documents, China's ecological civilization construction is gradually advancing. Ecological civilization needs legal response. China's General Principles of Civil Law established "green principle" as the basic principle of civil law for the first time, and carried out through various systems in the specific provisions of civil code. This paper adopts the sociological analysis method to sort out the interaction between legislation and society, and then puts forward some Suggestions to improve the legislation of civil code. In the published draft of civil code, the Ecologization of Torts Law is the highlight, and the compensation system for ecological environment damage is detailed and specific. However, there is still much room for improvements in property rights, contract and personality rights. In order to meet the needs of ecological civilization construction, the real right system should be adjusted in the concept of real right and  the attitude of animals; the contract system should make a breakthrough in the named contract types and regulate carbon trading; in the specific personality right system, the environmental right should be protected by the expansion of the protection of rights and interests in the tort liability law.

This article uses the odd Lomax-G family of distributions to study a new extension of the Kumaraswamy distribution called “odd Lomax-Kumaraswamy distribution”. In this article, the density and distribution functions of the odd Lomax-Kumaraswamy distribution are defined and studied with many other properties of the distribution such as the ordinary moments, moment generating function, characteristic function, quantile function, reliability functions, order statistics and other useful measures. The model parameters are estimated by the method of maximum likelihood. The goodness-of-fit of the proposed distribution is demonstrated using two real data sets.

Luffa cylindrica is locally a source of food, medicinal substances and have other traditional application. This study investigated the proximate and mineral analysis of L. cylindrica. The result of the analysis showed that the seed contain principally protein (35.83%) and fat content (33.93%). The crude fiber, moisture and ash content are 4.58, 5.84 and 6.13% respectively, while 13.67% was found as the carbohydrate content which is determine by different methods. The mineral content showed that phosphorus is the most abundant mineral with 30.63 mg/100 g followed by Magnesium (28.93 mg/100 g). It also contains moderately high amount of other minerals such as Potassium (13.86 mg/100 g), Sodium (8.18 mg/100 g) while Chromium (0.25 mg/100 g) was found to be the lowest. The sample could be useful in preventing high blood pressure. Thus, the research suggests that L. cylindrica seed can serve as a potential source of vegetable protein and mineral in dietary formulation.

In recent years, the rapid industrialization leads to increase industrial discharges without any appropriate treatment. The present study deals with the removal of Cr (III) ions from aqueous solutions by ZnCl₂ treated biochar produced from vegetable tanned leather shaving dust. Effect of various process parameters like solution pH, adsorbent dose, adsorbent type, initial Cr (III) concentration and temperature have been studied in batch system. The thermal resistivity and scanning electron microscopy (SEM) analysis were engaged to perceive the surface morphologies of chemically treated and untreated biochar adsorbent. The experimental data was fitted well to the Langmuir adsorption isotherm model and the adsorption efficiency of chromium (III) was found to be maximum (70%) at low values of pH (around 3) for 0.75 g/50 mL dose of ZnCl₂ treated biochar adsorbent. The model matrix of 2⁴ full factorial design approach has been applied at a 95% confidence level to find the impact of different variables on removal Cr(III) ions from waste water. This study revealed that three main factors: Adsorbent type (p < 0.0001; 66.39%), pH (p < 0.001; 16.01%) and adsorbent dose (p = 0.032; 12.15%) have significant impact on Cr (III) ions removal efficiency. For using ZnCl₂ biochar, Cr(III) ions removal efficiency was increased 66.39% compared to using untreated biochar. Subsequently, two interaction factors: pH-time and adsorbent type-time (α = 0.05, p < 0.05) have shown statistically significant on Cr(III) ions removal efficiency. The ZnCl₂ treated biochar adsorbent prepared from vegetable tanned leather shaving dust is efficient and it is proposed that it can be conveniently employed as a low cost alternative in the treatment of industrial waste water.

Background: Bush fire is a common hazard in South East-Nigeria as in other parts of the country during the harmattan. Every year, thousands of hectares of forests as well as suburban lands are severely burnt. These forest fires have been catastrophic, destroying large areas of tropical rain forests and in most cases have claimed many lives and destroyed properties worth millions of naira. However, some of these trees identified by local people and named by taxonomists as Daniellia oliveri, Anacadium occidentale, Vitex doniana, Lonchocarpus griffonianus, Gmelina arborea, Nauclea latifolia, Tectona grandis, Mangifera indica, Delonix regia, Newbouldia laevis, Azadirachta indica, Dialium guineense, Terminalia superba, Manilkara obovata and Irvingia gabonensis have proven to be fire tolerant.

Aim: The aim is to establish correlations among the physical properties (wood density and moisture content) and flame characteristics (ignition time, flame propagation rate, flame duration, afterglow time, ash formation and limiting oxygen index) of these fire tolerant trees.

Study Design: An item structured instrument was developed by the researchers which reflected the six points modified Likert scale of strongly agree, agree, somewhat agree, somewhat disagree, disagree, strongly disagree and used to elicit information from the respondents who were mainly seasoned wood dealers of above 60 years of age. Analysis of Variance (ANOVA) was the major tool of analysis used to establish whether the tree species tolerates fire or not while correlation of the parameters was achieved by the application of R².

Place and Duration of Study: Determination of both the physical properties and flame characteristics of the tree species was done at the Research Laboratory of the Department of Pure and Industrial Chemistry, Nnamdi Azikiwe University, Awka between June, 2018 and April, 2019.

Methodology: The physical properties of the tree species as well as their flame characteristics were carried out using their standard methods.

Results: The values for these parameters vary among the tree species. Correlation among the parameters indicates a determination coefficient range from 0.000 to 0.637.

Conclusion: There are highly significant correlations between wood density and both ignition time and flame propagation rate as well as wood density and limiting oxygen index. There is also strong correlation between ignition time and both flame propagation rate and limiting oxygen index. Afterglow time depends on limiting oxygen index and vice versa.

Background: Management of structural heart diseases is quite challenging in Nigeria, due to limited availability and access to cardiac care services. There is paucity of data on the pattern and outcome of cardiac interventions in children from the study area. 

Aims: To determine the pattern of cardiac interventions and the early outcome (within six-months) of such interventions in children with structural heart diseases (SHD) seen in our hospital.

Study Design: Descriptive cross-sectional study.

Place and Duration of Study: Department of Paediatrics, Usmanu Danfodiyo University Teaching Hospital (UDUTH), Sokoto, between August 2012 to September 2019.

Methodology: All children with SHDs seen at our hospital, but had Cardiac surgery or interventional cardiac procedures within and outside Nigeria were recruited. Relevant information including type of lesion, procedure performed and the outcome within the first six months and length of hospital stay was analyzed.

Results: Only 63 out of 780 (8.1%) children with structural heart diseases, aged 6 months-15 years (Mean age 6.5± 5.0 years, M: F = 1.3:1), had cardiac interventions. The interventions were surgical in 61 ((96.8%) and catheter-based in 2 (3.2%) patients; with 49 (77.8%) of these performed abroad. Patent Ductus arteriosus 14 (22.2%), Tetralogy of Fallot 14 (22.2%), ventricular septal defect 13 (20.6%) and atrial septal defect 6 (9.5%) were the commonest lesions for which interventions were undertaken. Early post-operative complications included pulmonary hypertensive crises, pericardial and pleural effusion, complete heart block and left branch pulmonary artery stenosis warranting re-intervention. During the first six months after the interventions, three (4.8%) patients died while 60 (95.2%) survivors were followed up. However, 25 (39.7%) of them were thereafter lost to follow.

Conclusion: Majority of the cardiac interventions were surgical, performed predominantly in older children with CHDs; and associated with good outcome. However, most of them were undertaken outside the country, highlighting the need to ensure these services are available and accessible locally.   

The main aim of the study was to examine factors that affect women’s household decision-making among married women in Zambia. This paper utilizes secondary data from the 2013 Zambia Demographic Health Survey (ZDHS). Logistic regression analysis was used to identify various factors associated with factors that affect women’s autonomy in household decision-making among married women in Zambia. The findings of the study show that married women in Zambia are more likely to participate in decision-making that involved purchases of daily household needs (86%) followed by decision making that involved visits to her family or relatives (75%) and decisions about her own health care (74%). About 66per cent of the respondents reported having participated in household major purposes. Some socio-demographic variables only influenced women in some domains and not all. For instance, age only influenced decision-making on household goods and visits to family. Rich wealthy status, living in urban areas, higher levels of education and justification of wife-beating were influential to healthcare decision-making among women. Zambian programmes and policy initiatives should develop a clear policy foundation that should be crucial to empower women to take part in decision-making processes in the household. Moreover, enhancing their access to and control over economic resources and enabling them to establish and realise their rights are also essential means to empower women to be more autonomous in decision-making.

Aims/ Objectives: This research was carried out with the intention of using time series to model the volume of overland timber exported within Bolgatanga municipality
Place and Duration of Study: Study of the time series was based on a historical data of the volume of timber exported for twenty consecutive years, from 1999 to 2019 within Bolgatanga municipality.
Methodology: The three-stage iterative modeling approach for Box Jenkins was used to match an ARIMA model and to forecast both the amount of timber export and the confiscated lumber. ARIMA method incorporates a cycle of autoregressive and a moving average. The three-stage iterative modeling technique of Box Jenkins which were used are model recognition, parameter estimation and/or diagnostic checks were also made.

Results: From the preliminary investigation, the study showed that the amount of timber exported in municipality is skewed to the right, suggesting that much of the amount of timber exported is below the average. This, together with the high volatility in the volume of timber exported, indicates that the amount of timber exported within the municipalities during the twenty-year period was low. The plots from the trends also showed robust variations in the volume of timber exported indicating that timber exporters do not have better grips with the concepts and applications of export technology, hence the erratic nature of the volume of timber exported over the period. The quadratic pattern and the ARIMA (1,1,1) model best represented the amount of timber exported.
The analysis further indicated that there will be a further decrease in the amount of timber export from the five years projection into the future. Over the last two decades the Bayesian approach to VAR has gained ground. For a future report, this estimation method will be followed to examine the ”long-run equilibrium relationships” between timber export volumes and climate change.
Conclusion: The quadratic pattern and the ARIMA (1,1,1) model best represented the amount of timber exported. There will be a further decrease in the amount of timber export from the five years projection into the future.

Wind energy conversion systems continue to show promises as energy source of the future. To champion the supply for future industrial and domestic energy demand, it is imperative to improve on their reliability, energy extraction efficiency and security as these factors would enormously affect their viability and deployment. This paper presents an overview of the applications of power electronics to speed control of generators in wind energy conversion systems. Wind energy conversion system, the basis on which they are classified and their various components are concisely reviewed. Further, an up-to-date highlight of wind turbines speed control schemes is presented with focus on the roles of power electronics in these schemes. Concluding, necessary technological and economic development to aid applications of power electronics devices in emerging wind energy systems and their significance to the microgrid is understudied.