Journal of Scientific Research and Reports
EISSN : 2320-0227
Published by: Sciencedomain International (10.9734)
Total articles ≅ 1,398
Latest articles in this journal
Published: 16 October 2021
Journal of Scientific Research and Reports pp 139-145; https://doi.org/10.9734/jsrr/2021/v27i930443
Production characteristics and compositions of constituent ingredients of concrete influence to a large extent the quality of concrete works in general. The levels of implication of these factors on performance of concrete are therefore appraised for improved production of concrete work in the study area. Experimental research method was adopted to obtain data on the compressive strength of concrete produced at some construction sites in the study area. A preliminary survey conducted confirmed that 1:2:4 and 1:3:6 mix ratios are commonly used as their mix designs. Forty eight concrete cubes of 150mm x 150mm x 150mm were used to collect sample at the selected sites for the laboratory tests. Product moment correlation coefficient was used to determine the strength of relationship for changes in the increasing strength of concrete with increase in curing ages between concrete produced with sedimentary and granite aggregates. On the other hand, differences in proportion of variation on strength of 1:2:4 and 1:3:6 concrete mix ratios between concrete produced with the various types of aggregates at 7-day and 28-day curing ages respectively were analyzed using Z–test statistics. Findings reveal that it is only concrete produced with granite material aggregate at the 28-day curing age reached the minimum stipulated standard strength values of 21N/mm2 and 18N/mm2 for 1:2:4 and 1:3:6 concrete mix ratios respectively. The correlation coefficient (r) of 0.999 and 0.993 for 1:2:4 and 1:3:6 concrete mix ratios respectively were calculated to confirm very strong association in changes in strength as the curing age increases between concrete produced with the two different aggregates. The difference in proportion of the variations in the two different mix ratios between the two different aggregates at the curing ages however are not significant in the study. Thus, the study concludes that mix ratio and curing age which remain positively strong on their effects on quality of concrete are as well significant as aggregate type in the overall performance of concrete. Granite material aggregate therefore was recommended to be used for concrete production of higher quality; and as well be always cured till the 28th day of production for desired strength of the concrete.
Published: 16 October 2021
Journal of Scientific Research and Reports pp 1-6; https://doi.org/10.9734/jsrr/2021/v27i1030442
Quality of concrete explains considerably the state of affairs involved in the production of concrete in a particular area. The antecedents of the production process to a greater extent therefore have a way of predicting the expected quality of a product. Hence, the degree of relationship between the quality of concrete and its production characteristics is determined in the study. Field work adopted in the study comprises activity sampling and ex post facto experimental designs. These two different research designs were applied to obtain data for performance assessment of activities involved in the production procedures and laboratory tests of concrete produced at various sites in the study area respectively. The corresponding data obtained in the field work are in ordinance and ratio scales of measurement. Regression analysis was used to establish a casual relationship between the two variables - performance level of the production characteristics (x) and the compressive strength (y) of the concrete at various sites in the study area. A model relationship of simple regression analysis for the dependent and independent variables is established. Finding reveals that the better the ranking of sites in compliance with the standard practice of production characteristics, the higher the compressive strength property of the concrete produced on site; hence the linear relationship. The coefficient of determination shows that 93% of changes in the strength property of concrete are caused by the production characteristics. Although the highest value of compressive strength obtained as 10.80 N/mm2 goes with the best state of affairs of the production characteristics in the study, it does not meet the minimum stipulated specification for the strength. Hence, other critical factors such as; aggregate type, and mix design should be considered for desired quality of concrete in the study area. Besides, enforcement of uniformity in production process as standard practice by all the firms should as a matter of urgency be implemented formally by the government in the state for improved quality of concrete in general.
Published: 15 October 2021
Journal of Scientific Research and Reports pp 131-138; https://doi.org/10.9734/jsrr/2021/v27i930441
Knowledge of activity concentration of radionuclides in soil of our farmlands and the consequent transfer factors of the radionuclide to plants are necessary to estimate the contamination level of the soil, plants and food. The activity concentration of 40K, 238U and 232Th in soils and cassava in Ini Local Government Area, Akwa Ibom State, Nigeria were measured using gamma spectrometry. Activity concentrations of radionuclides in soils in the locations ranged from BDL (below detectable limit) to 298.76 ± 21.40 Bq/Kg for 40K; BDL to 7.95 ± 1.88 Bq/Kg for 238U and 2.59 ± 0.25 to 16.56 ± 1.61 Bq/Kg for 232Th. Activity concentration of the radionuclides in cassava in all locations ranged from 213.96 ± 15.38 Bq/kg to 520.58 ± 37.25 Bq//Kg for 40K; BDL to 33.02 ± 8.91 Bg/Kg for 238U and BDL to 16.34 ± 1.59 Bq/kg for 232Th. The activity concentrations of all the radionuclides were lower than the world standard. Transfer factors obtained ranged between 3.21 to 4.18 for 40K; 0.93 to 12.64 for 238U and 0.75 to 1.01 for 232Th. Effective ingestion dose due to the consumption of cassava from the studied area obtained ranged between 1.31 to 1.74 mSv/yr and 3.52 to 4.69 mSv/yr for children and adult respectively. These values are above the 1.0 mSv/yr recommended dose limit for general public, therefore the consumption of this food stuff could pose a radiological health effect on humans. However the risk could be minimized when the cassava is cooked.
Published: 12 October 2021
Journal of Scientific Research and Reports pp 123-130; https://doi.org/10.9734/jsrr/2021/v27i930440
A crossover design is a repeated measurements design such that each experimental unit receives different treatments during the different time periods. In a majority of bioequivalence studies, design and analysis of cross-over using classical methods such as analysis of variance (ANOVA) and test are normally associated with erroneous results. The Bayesian method is desirable in the analysis of crossover designs to eliminate errors associated with carryover effects. The objective of this study was to compare the Bayesian and the - test analysis methods on treatments and carryover effects for an optimal two treatments, five periods and four sequence C (2, 5, 4) design. The treatments and residual estimates were obtained using Best Linear Unbiased Estimation (BLUE) method. In the Bayesian method of analysis, the posterior quantities were obtained for the mean intervals of treatments and carry-over effects and the highest posterior density (HPD) graphs were plotted and interpreted using conditional probability statements. For validation purposes, the Bayesian method results were compared with the existing -tests results. From the Bayesian analysis, the probability of significant treatment difference in the presence of carryover effects was 1, while from the -test, the calculated value of 11.73 was greater than the two sided tabulated value at 95 level of significance. The two analysis methods implied significant differences in the treatment effects. In conclusion, it was established that Bayesian method of analysis can be used for bioequivalence analysis even when the carry-over effects are present and hence it is highly recommended for bioequivalence studies.
Published: 11 October 2021
Journal of Scientific Research and Reports pp 56-105; https://doi.org/10.9734/jsrr/2021/v27i930437
The drugs mostly present are available with less bioavailability and the problem arises with less permeation or solubility so extensive work is done to enhance these mechanisms. Not only that drugs should pass hepatic metabolism, Inorder to improve its bioavailability they are formulated as transferosomes which can improve the patient compliance by delivering the drug through the transdermal-route. Soya lecithin is used as a phospholipid whereas Tween 60, Tween 80, Span 60 and Span 80 are used as edge activators. These formulations usually showed more entrapment efficiency. The reason behind this is due to the presence of more phospholipids and as the surfactant concentration increases drug release will be rapid. As our main aim is to enhance the bioavailability this can be achieved by optimizing the concentrations of phospholipid and surfactant one can attain a controlled release of drug through this drug delivery system.
Published: 11 October 2021
Journal of Scientific Research and Reports pp 106-122; https://doi.org/10.9734/jsrr/2021/v27i930438
Digital age has created an unregulated war environment and there are non-state actors, armed groups, terrorists, and criminals which should be faced by established governments. Therefore, in the military context today, soldiers as national security guards no longer face physical forms of combat only, information, however, has became the front line in the national security landscape and needs to be treated equally with the land, sea and air defense dimensions. This study aims to reveal how digital literacy and leadership improve professional performance of soldiers through collaborative decision making as mediator, which can be applied not only in the military environment but also in soldier’s interaction with the civilian community in their social life. Quantitative approach with an explanatory survey is used in this study in order to explain symptoms and determine the causal relationship between variables, while the unit of analysis is soldiers from various divisions and ranks with a sample size of 3,598 soldiers from all over Indonesia. The results show that increasing digital literacy and leadership will improve professional performance of the soldiers through collaborative decision making. Leaders should initiate digital leadership in order to develop digital literacy of the soldiers as well as employ digital based internal collaborative decision-making platforms in order to improve not only the professional performance of soldiers but also the organization effectiveness in general.
Published: 5 October 2021
Journal of Scientific Research and Reports pp 49-55; https://doi.org/10.9734/jsrr/2021/v27i930435
Introduction: Agriculture is fundamental for society, being important in the production of food to meet the demand of the population that has been growing, using various methods to improve the productivity of agricultural crops. To ensure that the crop has its production, adequate crop management must be carried out, and the control of pests, diseases and weeds, for this, one of the methods used today, is chemical control. Aims: The objective of this work is to carry out a brief review of the literature on chemical control problems in agriculture, a social perspective, describing its importance in the agricultural sector. Literature Review: Chemical control brought many benefits and allowed agriculture to gain a boost in its production, due to the benefits provided by its use in the control of pests, diseases and weeds, but it caused some problems with its use, in the social, environmental and in the agricultural sector. These problems had many consequences, and over time, by adopting sustainable rural development, seeking sustainable production, the objective was to reduce the use of agrochemicals, by using alternative means of pest, disease and weed control. The means of control mainly used are biological and cultural control, associated with the awareness of the population, which together favors the reduction of the need for chemical control in crops, reducing costs, maintaining the sustainability of the agricultural sector, ensuring that plant can produce, and enabling a more sustainable production. Final Considerations: Using alternative means of control, social awareness, and following sustainable development, agriculture is becoming more suitable in all aspects, whether social, environmental and economic, helping the development of society as a whole, providing agriculture with less use of chemical control, and a more sustainable model.
Published: 4 October 2021
Journal of Scientific Research and Reports pp 41-48; https://doi.org/10.9734/jsrr/2021/v27i930434
The impact of mental wellness on the work performance and wellbeing of workers has generated much academic and corporate debates. Most recently, due to some high-profile cases involving the performance and wellness of sports people, conversations around the impact of mental wellness on work performance have dominated public discourse, yet the nature and degree of this impact has not been sufficiently studied and analysed and many questions remain unanswered. Indeed, there has been a growing awareness of the centrality of the role of mental wellness in the productivity of workers, especially in the Oil and Gas industry. Thus, this research sought to investigate how rotational work, its impact on sleep and endurance, affect workers in the Oil and Gas industry, using as methodology a simple random sampling of workers from the Port Harcourt metropolis, in the oil-rich delta area of Nigeria. To obtain data, this research used questionnaires, telephone interviews and cohort discussion session. Questions posed during this research focused on sleep and its perceived effect on endurance. The questionnaires were administered to the workers from selected international Oil and Gas companies located in Port Harcourt. Findings revealed that both sleep and the circadian cycle were negatively affected and impacting the self-reported well-being and productivity of the workers. From the data collected, 27.5% and 66.2%, which represented a total of 93.7% of the respondents, agreed and strongly agreed that their sleep was affected. 100% of the participants in the cohort session agreed that their sleep was affected. Furthermore, the interview sessions revealed specific details as more than 50% of the interview respondents indicated that the sleep distortion affected them even up to the first week of their time off. 48.8% and 37.5% agreed and strongly agreed to the fact that rotational work had effect on their endurance on site. This represented a total of 86.2% of the participants whose endurance level was affected due to rotational work. Over 60% of the participants in the cohort session admitted to feeling of extreme tiredness towards the end of their rotation period and prior to departure from site. The participants unanimously submitted that shorter rotation would give room for adequate recuperation and make work more productive and enhance the sense of mental wellness for rotational Oil and Gas workers.
Published: 30 September 2021
Journal of Scientific Research and Reports pp 19-31; https://doi.org/10.9734/jsrr/2021/v27i930432
Background: Providing occupational health and safety (OHS) services to employees has been a global problem for an extended period. A safe workplace should pose no avoidable risk to employees' physical, psychological, or social wellbeing and should provide opportunities for employees to improve and support their health. This study aimed to assess the occupational health and safety risks and hazards among workers at the construction sites in Kombo North District of the Gambia. Methods: A mixed-method study design was conducted across construction workers in Kombo North District, West Coast Region of the Gambia. Data was generated using validated OHS risk assessment matrix, structured questionnaires, environmental and physical inspection and key informant interviews. Descriptive statistics, including a composite scoring system, were used to present the results of this study. Results: Of the 157 respondents in this study, 98.1% were males, and about one-third of these construction workers were 31-40 years of age. About 46% and 34.4% spent 1-5 and 6-10 years in the construction industry, while about 40.2% of the respondents never been to school. The study revealed that physical risks and hazards in the form of falling from a height, electric shock, etc. were the most common forms compared to other categories such as ergonomics, biological and chemical risks and hazards. There is no reporting system or registry in place across the study sites. Conclusion: This study provides evidence that physical hazards reported being the most common across other forms of ergonomics, biological and chemical risk and hazards. There is an urgent need for reactivation and implementation of OHS advocacies, health education, and other preventive strategies to control common workplace risks and hazards in their various forms.
Published: 30 September 2021
Journal of Scientific Research and Reports pp 32-40; https://doi.org/10.9734/jsrr/2021/v27i930433
The present work is concerned with the development of a simple transient mathematical model for the oxygen diffusion-consumption in the eye lens. The model takes into account the transport of oxygen by diffusion and consumption of oxygen is assumed to follow the Michaelis- Menten’s kinetics. The partial differential equation governing the partial pressure of oxygen has been solved by using implicit Crank-Nicholson’s iteration scheme. The prime objective of the present study is to investigate the effect of model parameters: the Michaelis- Menten’s kinetic constant and maximum rate of consumption on the partial pressure of oxygen in the mammalian lens. The computational results of the model have been presented by graphs and effects of model parameters also have been shown through the graphs and discussed. The present mathematical analysis of oxygen diffusion in the lens may contribute to the knowledge of regulation of tissue oxygen in the lens and quantitative understanding achieved through the analysis may facilitate the design of new therapeutic procedures. This analysis may help in regulating the partial pressure of oxygen in the lens.