Open Journal of Applied Sciences

Journal Information
ISSN / EISSN : 2165-3917 / 2165-3925
Current Publisher: Scientific Research Publishing, Inc. (10.4236)
Former Publisher: Scientific Research Publishing, Inc. (10.4236)
Total articles ≅ 707
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Xiaofang Yang, Yongxi Jiang, Tianxiu Lu
Open Journal of Applied Sciences, Volume 11, pp 343-353; doi:10.4236/ojapps.2021.113025

Abstract:
Let be a non-autonomous discrete system and be a set-valued discrete system induced by it. Where, is the space formed by all non-empty compact subsets of X endowed with the Hausdorff metric H, is a set-valued mapping sequence induced by . It is proved that is -chaos, then is -chaos. Where -chaos is denoted to -sensitive, -sensitive, -transitive, -accessible, -weakly mixing, -m-sensitive, infinitely sensitive, or syndetically transitive.
Ernest Owusu-Sekyere, George Obeng-Akrofi, Joseph O. Akowuah, Dirk Maier
Open Journal of Applied Sciences, Volume 11, pp 327-342; doi:10.4236/ojapps.2021.113024

Abstract:
The performance of an AflaSTOP dryer which utilises biomass energy for drying maize was investigated. The drying behaviour of maize grains in the dryer was also investigated using ten (10) thin-layer mathematical models. The models were compared based on coefficient of determination (R2) and Root Mean Square Error (RMSE) values between experimental and predicted moisture ratios. At an average drying air temperature of 50°C and drying air velocity of 2.5 m/s, maize at average moisture content (MC) of 17.5% (wb) was dried to an average MC of 11.5% (wb) in three (3) hours. The drying and thermal efficiency were calculated as 81.1% and 29.6% respectively. Overall, drying took place in the falling rate period. The Logistics model was best to describe the thin-layer drying kinetics of maize in the dryer with R2 value of 0.9902 and RMSE value of 0.04908.
Avijit Podder, Mahmud Alam
Open Journal of Applied Sciences, Volume 11, pp 312-326; doi:10.4236/ojapps.2021.113023

Abstract:
Unsteady extracellular fluid (ECF) flow along with a rotating infinite vertical porous plate in the presence of a transverse magnetic field has been studied numerically. The dimensional governing equations have been non-dimensionalized by useful dimensionless variables. The explicit finite difference method has been used to solve dimensionless equations. The numerical results have been calculated by studio developer FORTRAN 6.6a and MATLAB 2018a. For perfect conducting case, Magnetic Diffusivity Parameter 5 ≤ Pm ≤ 15 has been taken in induction equation. For good accuracy, stability and convergence analysis have been analyzed. Mesh Sensitivity test, steady-state solution test, and code validation test have been performed. For time step τ = 1, the numerical results have been found for the primary velocity, secondary velocity, angular velocity, primary induced magnetic field, secondary induced magnetic field, temperature as well as shear stresses along x and z direction, couple stress along z direction, current densities along x and z direction and the Nusselt number. Finally, the effects of various parameters have been separately discussed and illustrated graphically.
Merve Ozcan, Cemal Ozsut, Oguzhan Deveci, Gulbahar Bentesen
Open Journal of Applied Sciences, Volume 10, pp 414-421; doi:10.4236/ojapps.2021.104030

Abstract:
It is aimed to investigate the efficiency of nitrogen gas cooling which is used in aluminium extrusion mold in this study. The exit temperature of extrusion profile increases depending on heat generated by friction and forming. This situation can cause to surface defects such as hot cracks and grain thickening after extrusion process. Cooling of the mold has a critical role in terms of dissipating heat close to the forming zone. Local internal cooling experiments were performed in the hot aluminium extrusion mold within the scope of this study. It has been obtained that exit temperature of the aluminium extrusion profile can be significantly reduced in experimental results. Also it was found that the reduction of press time (s) and increase of press speed (mm/s). This paper focuses the effect of nitrogen gas cooling on extrusion mold for process efficiency. The extrusion parameters were performed for comparative analysis. Its obtained that process ensures efficiency.
Ayuna Sulekan, Jamaludin Suhaila, Nurmarni Athirah Abdul Wahid
Open Journal of Applied Sciences, Volume 10, pp 549-563; doi:10.4236/ojapps.2021.104039

Abstract:
Changes in climate factors such as temperature, rainfall, humidity, and wind speed are natural processes that could significantly impact the incidence of infectious diseases. Dengue is a widespread disease that has often been documented when it comes to the impact of climate change. It has become a significant concern, especially for the Malaysian health authorities, due to its rapid spread and serious effects, leading to loss of life. Several statistical models were performed to identify climatic factors associated with infectious diseases. However, because of the complex and nonlinear interactions between climate variables and disease components, modelling their relationships have become the main challenge in climate-health studies. Hence, this study proposed a Generalized Linear Model (GLM) via Poisson and Negative Binomial to examine the effects of the climate factors on dengue incidence by considering the collinearity between variables. This study focuses on the dengue hot spots in Malaysia for the year 2014. Since there exists collinearity between climate factors, the analysis was done separately using three different models. The study revealed that rainfall, temperature, humidity, and wind speed were statistically significant with dengue incidence, and most of them shown a negative effect. Of all variables, wind speed has the most significant impact on dengue incidence. Having this kind of relationships, policymakers should formulate better plans such that precautionary steps can be taken to reduce the spread of dengue diseases.
Kwashie A. Armah, Joseph O. Akowuah, George Obeng-Akrofi, Samuel G. McNeill
Open Journal of Applied Sciences, Volume 11, pp 157-175; doi:10.4236/ojapps.2021.111011

Abstract:
The solar bubble dryer (SBD) is a convenient and better option to traditional open sun drying commonly practiced by smallholder farmers in Ghana and other developing countries. However, to operate the SBD, one is faced with the challenge of frequent mixing of grains using a rake to enhance uniform drying and prevent over-heating of the top-layer exposed to the sun. Additionally, condensation in the SBD can compromise the quality of grains during drying under humid conditions. In the present study, the Analytical Hierarchy Process (AHP) was used to select an appropriate drying platform, tarpaulin, or elevated drying rack for maize drying in the SBD. Using the AHP, the elevated drying rack was chosen as a suitable platform for drying maize in the SBD. The SBD with the elevated drying racks was used to dry 270 kg of maize from a moisture content of 18.2% to 12.6% (w.w.b) within 6 hours compared to 11 hours for the same quantity of grains dried on the tarpaulin of the SBD to reach an MC of 12.5% (w.w.b). An average drying rate and moisture extraction rate of 0.93%/h and 2.88 kg/h were achieved with the elevated drying rack system compared to 0.52%/h and 1.60 kg/h when drying on the tarpaulin of the SBD. An average temperature of 44.6°C recorded in the SBD was 9°C more compared to the ambient temperature. The thermal efficiency of the SBD collector was determined as 36.2%. Drying grains with the elevated racks showed advantages of reduced drying time, improved airflow through the drying bed, and prevention of condensation, which occurs when drying on the tarpaulin of the SBD.
Ching-Hui Lin, Ying-Wan Chuang
Open Journal of Applied Sciences, Volume 11, pp 190-201; doi:10.4236/ojapps.2021.112013

Abstract:
In recent years, camping is popular in Taiwan, but the research on campers’ participation behavior is still insufficient. The purpose of this research is to analyze the structural relationship between camping tourists’ motivation, experience, and satisfaction. The survey was conducted in a convenient sampling method, and a total of 464 valid questionnaires were collected. After descriptive statistics and partial least squares (PLS) statistics analysis, the results show that the higher the motivation of camping tourists, the more positive their experience and the higher their satisfaction. In addition, this research also confirms that experience has a mediating effect on motivation and satisfaction in terms of academic theory.
Lynn Slama, Nathan Huysman, Jill M. Voorhees, Michael E. Barnes
Open Journal of Applied Sciences, Volume 11, pp 287-293; doi:10.4236/ojapps.2021.113021

Abstract:
Eyed salmonid eggs can be subjected to large temperature swings during development, particularly when shipped in ice-filled containers from broodstock facilities to production hatcheries. This study examined the effect of thermal tempering on the survival of brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss eyed eggs to hatch. Eyed eggs at 1°C were either directly placed in 11°C water or allowed to thermally temper from 1°C to 11°C gradually over an hour. In addition, each of the tempering treatments occurred either with or without a 10-minute iodophor disinfection treatment. Tempering had no significant effect on survival-to-hatch in either species (85% - 97%). However, survival was significantly lower in rainbow trout eggs subjected to iodine disinfection (73% - 75%) compared to non-disinfected eggs (91% - 97%), likely because of the close proximity to hatch. The results of this study indicate that slowly raising the temperature (thermal tempering) of brown trout and rainbow trout eyed eggs is unnecessary. Additionally, iodine disinfection of eyed salmonid eggs in close proximity to hatching should be avoided.
Aristide H. W. Nakavoua, Louis Okotaka Ebale, Bertin Mikolo, Vincent Verney, Gilles Figuérédo
Open Journal of Applied Sciences, Volume 11, pp 264-272; doi:10.4236/ojapps.2021.113019

Abstract:
The study of the polymerization of a vegetable oil has a double interest; industrial but especially food. Industrial because polymers based on vegetable oil are in line with sustainable development; food because an oil which polymerizes easily is a danger for human consumption. Three situations of Cucurbita pepo oil polymerization are carried out in the course of time, the factor retained being temperature. A monitoring of the evolution of the enthalpy by temperature variation by the DSC method allows to report the polymerization of this oil. It happens that a polymerization is triggered in the oil matrix but it seems to fade very quickly, this behavior is general because after sweeping a temperature range of 80°C; 100°C and 150°C adding different amounts of Irgacure: the Cucurbita pepo oil resists polymerization through its antioxidant compounds. However, a photolysis of this oil carried out over 8 days shows that it effectively polymerizes after 144 hours, which proves the great capacity of antioxidant compounds to protect this oil. The analyses carried out at 25°C aim to simulate the behavior of the oil at room temperature. The results reveal good resistance to both thermochemical and photochemical polymerization, which opens up great prospects for its development in the food industry and in nutrition.
Riad M. Abughalia, Milad A. Alrzini, Karima R. Zarug Edawib
Open Journal of Applied Sciences, Volume 11, pp 11-20; doi:10.4236/ojapps.2021.111002

Abstract:
Data from recent studies revealed that kidney diseases might affect the thyroid function in various ways. A variety of alterations in thyroid hormone levels and metabolism have also been reported in patients with chronic renal failure (CRF) in some studied population. In addition, it was reported that serum levels of both T3 and T4 might alter immediately after a hemodialysis (HD) treatment than before. Therefore, this study was aimed to investigate the level of triiodothyronine (T3) and thyroxine (T4) in CRF Libyan patients before and after HD. This study was carried out on 46 CRF patients (30 males and 16 females) with a mean age of 47.46 ± 15.75 years. These patients were treated at the hemodialysis unit of Educational Central Zelitin Hospital, Zelitin, Libya. None of these patients apparently have any thyroid problems and no history of drug intake that may affect thyroid function. Blood samples were taken from each patient to measure serum levels of T3 and T4, before and after HD. In addition, the effects of several variables including age, gender, body mass index (BMI), presence of both hypertension and, diabetes mellitus and duration of kidney dialysis on serum levels of T3 and T4 before and after HD were also studied. After HD, there was a statistically significant increase in the serum levels of T3, T4. The age, gender, BMI, duration of kidney dialysis and the presence of hypertension and diabetes mellitus did not have any significant effect on the serum level of T3 and T4 before and after HD. However, the serum levels of T3 and T4 were still in the normal range in these examined patients either before or after HD. From these findings, it can be concluded that these CRF patients may be in a euthyroid state, because the serum levels of T3 and T4 were in the normal range. In addition, HD was seemed to improve the T3 and T4 thyroid hormone concentrations, suggesting that HD might activate the secretion of thyroid gland and catabolism. The other variables did not play any role in thyroid hormone levels in these patients either before or after HD. It is highly recommended that large scale evaluation of thyroid hormone levels in Libyan CRF patients is performed by more patients, especially elderly patients.
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