A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z  

  Subjects -> SCIENCES: COMPREHENSIVE WORKS (Total: 374 journals)
The end of the list has been reached or no journals were found for your choice.
Similar Journals
Journal Cover
Journal of Science and Technology
Number of Followers: 2  

  This is an Open Access Journal Open Access journal
ISSN (Print) 2229-8460
Published by Universiti Tun Hussein Onn Malaysia Homepage  [2 journals]
  • The Effect of Nanowire Gap for Silicon Nanowire Transistor to the
           Current-Voltage (I-Vds)

    • Authors: Ahmad Makarimi Abdullah, Khatijah Aisha Yaacob, Nurain Najihah Alias, Mohd Azraie Mohd Azmi, Asrulnizam Abd Manaf
      Pages: 1 - 10
      Abstract: One-dimensional structures are attracting a lot of attention for optimizing applications as one of the most sensitive devices. Among the fabricated devices, silicon nanowires (SiNW) and silicon nanowire transistors (SiNWT) are of particular importance for promising applications fabricated using bottom-up or top-down approaches to nanoscale devices. In this paper, the sensitivity of the current-voltage characteristic to the nanowire gap of a silicon nanowire transistor (SiNWT) was analyzed. SiNWTs with different nanowire gaps were fabricated using scanning probe microscopy by local anodic oxidation (LOA). Varies gaps can be occurring during the fabrication processes and its can be controlled by RASTER programming in LAO. These gaps can give different results of the sensitivity to the volt-ampere response. However, these gaps can be neglected depending on the subject of the studies and important to the other study, especially in nano particle sensors. In this experiment, the nanowires gaps were developed in the range of 100.5-435.6 nm and had been plotted the measurement data with the volt-ampere response. The data was analyzed using a semiconductor analyzer connected to a HP 4156C SPA series software analysis model from Desert Cryogenics. From the results had been measured the Current-Voltage (IV) increases proportionally with the nanowire gap distance in the SINWT device and these results will give significant effects to the application in nanoparticle sensors.
      PubDate: 2023-12-13
      Issue No: Vol. 15, No. 2 (2023)
       
  • Aphrodisiac Potentials of Aqueous Extract of Azanza Garckeana Fruit Pulp
           in Fluoxetine-induced Sexually-impaired Female Rats

    • Authors: Quadri Olaide Nurudeen, Muhammed Robiu Asinmi, Mansurat Bolanle Falana, Muhammad Ali Dikwa
      Pages: 11 - 22
      Abstract: This study aims to investigate the potential of Azanza garckeana, a plant traditionally used as an aphrodisiac, to reverse sexual dysfunction induced by an antidepressant ‘fluoxetine’ in female rats. Aqueous extract of A. garckeana fruit pulp was screened for its secondary metabolite compositions. Female rats were induced into sexual dysfunction using fluoxetine, then they were divided into six groups, and treated based on the group with oral administration of varying doses of A. garckeana extract (125, 250, and 500 mg/kg body weight) and a reference medication (Tadalafil) for seven days. Sexual behaviour parameters were monitored and hormone levels (progesterone, follicle-stimulating hormone, luteinizing hormone, oestrogen, and prolactin) were measured after the treatment period. Fluoxetine significantly (p < 0.05) reduced the frequencies of sexual behaviours in the rats, such as darting, hopping, lordosis, genital grooming, and licking behaviour, but increased the latencies of darting and hopping. However, the extract, at 250 and 500 mg/kg, significantly (p < 0.05) reversed these changes in the sexual behavior of fluoxetine-induced rats in comparison to the effects of Tadalafil treatment. Furthermore, the extract significantly (p < 0.05) increased the levels of luteinizing hormone, follicle-stimulating hormone, progesterone, and prolactin in the blood but decreased oestrogen levels, especially at a dose of 500 mg/kg. The results of this study suggest that the aqueous extract of A. garckeana fruit pulp can improve sexual behavior and reproductive hormone concentrations, thereby potentially restoring sexual competence in sexually-dysfunctioned female rats. These findings provide additional support for the traditional use of A. garckeana in managing female sexual dysfunction.
      PubDate: 2023-12-13
      Issue No: Vol. 15, No. 2 (2023)
       
  • Generating Correlations for Specific Volume, Enthalpy, and Entropy of
           Opteon: Utilizing a Novel Data Fitting Method

    • Authors: Sylvester Mumah
      Pages: 23 - 34
      Abstract: Establishing precise data correlations is a fundamental necessity for effective design, simulation, and optimization of chemical processes. While several correlation-generating methods for data fitting exist, each brings a unique degree of complexity and accuracy. This study introduces a distinctive method, appropriately named, Proportional Nodes Method, for correlating data on surfaces with two independent variables, focusing on precise estimations of correlations for boundary curves and nodal variation at selected points. The application of the proportional node method results in a lower average percentage deviation than the Chebyshev polynomial method (±0.978 for the method utilizing Chebyshev polynomials and ±0.5378 for the Proportional Nodes Method). This novel method exhibits lower complexity and generates correlations with superior simplicity and accuracy. Furthermore, the method effectively develops correlations for three properties—specific volume, enthalpy, and entropy of superheated Opteon, a widely-used refrigerant in automotive air-conditioners. The resulting data shows a satisfactory percentage deviation from the actual data (<+0.22% for a specific volume, <+0.124 for enthalpy and <+0.125 for entropy). In addition, correlations have been generated for the saturated vapour. This method's potential extends to developing correlations for non-overlapping data with two independent variables, making it a powerful tool for chemical process optimization.
      PubDate: 2023-12-13
      Issue No: Vol. 15, No. 2 (2023)
       
  • Impacts of Biochar Treatments on Some Soil Properties and Micronutrient
           Availability

    • Authors: Hamza Badamasi, Ozoilo Onyeka Calistus, Umar Faruk Hassan, Mahmoud Auwal Adamu, Haruna Baba, Akanang Hannatu
      Pages: 35 - 42
      Abstract: The application of biochar as a soil amendment has been recognized as an environmentally friendly and highly efficient strategy for restoring the fertility of the soil and increasing agricultural productivity. In this study, the impacts of Senna tora biochar treatments on soil properties and micronutrient availability in the farmlands of Misau, Bauchi State, Nigeria, were investigated. A complete randomized design replicated three times, which included control soil (no biochar/0 day), 30 days, and 60 days of biochar treatments, was adapted based on the fact that incubation time affects biochar application in soil. After treatments, the biochar was removed and the soil samples from each treatment were analyzed for pH, soil bulk density (BD), cation exchange capacity (CEC), organic carbon (OC) and micronutrient levels using various analytical methods. The results of the analysis show pH, OC and CEC values increased significantly (p ≤ 0.05) from 6.66 to 7.89, 3.40 to 3.90 g/kg and 5.16 to 7.29 cmol/kg respectively, while BD decreased significantly from 1.56 to 1.48 g/cm3 after 60 days of biochar treatment. The levels of Mn, Cu and Zn increased from 188.25 to 286.12 mg/kg, 14.38 to 41.88 mg/kg and 68.63 to 140.19 mg/kg respectively, while levels of Fe decreased from 9460.00 to 4782.73 mg/kg after 60 days of biochar treatments. Application of Senna tora biochar has generally led to a significant improvement in the fertility of the soil. It is therefore recommended that Senna tora biochar be used in the field to demonstrate its practical application.
      PubDate: 2023-12-13
      Issue No: Vol. 15, No. 2 (2023)
       
  • Artificial Neural Network Based Prediction of Key Performance Indicators
           for Mobile Telecommunications

    • Authors: Abdulsemiu Olawuyi, Tolulope Tola Awofolaju, Hammed Oyebamiji Lasisi, Olatunde Oladepo
      Pages: 43 - 53
      Abstract: This paper presents the comparative studies among artificial neural network neurons. Four Key Performance Indicators were predicted using neural network. The Key Performance Indicators and weather parameters for Osun State University, Osogbo, Nigeria were employed. MATLAB R2020a was employed to develop the neural network models. Three different neural network models were developed. Model A, Model B and Model C with ten neurons, fifteen neurons and twenty neurons respectively, the hidden layer of the models was Log-sigmoid activation function, and the linear activation was used at the output layer of the models. The three models were compared using mean absolute error and mean square error. The best performing model was Model B with fifteen neurons. Its mean absolute error and mean square error is 0.0909 and 0.0123 respectively. The Model A with ten neurons was the least performing model with mean absolute error and mean square error of 0.0990 and 0.0148 respectively. The results show that for a model to be robust, several neurons should be tested to establish the most effective model.
      PubDate: 2023-12-13
      Issue No: Vol. 15, No. 2 (2023)
       
  • Variable Sample Size Control Charts for Monitoring the Multivariate
           Coefficient of Variation Based on Median Run Length and Expected Median
           Run Length

    • Authors: Hamed Karimi, Khai Wah Khaw, XinYing Chew, Zhi Lin Chong, Shiuh Tong Lim
      Pages: 54 - 80
      Abstract: The monitoring of a well-functioning process system has always held significant importance. In recent times, there has been notable attention towards employing control charts to oversee both univariate and multivariate coefficients of variation (MCV). This shift is in response to the concern of erroneous outcomes that can arise when traditional control charts are applied under the condition of dependent mean and standard deviation, as highlighted by prior research. To address this, the remedy lies in adopting the coefficient of variation. Furthermore, this study underscores the application of MCV in scenarios where multiple quality attributes are simultaneously under surveillance within an industrial process. This aspect has demonstrated considerable enhancement in chart performance, especially when incorporating the variable sample size (VSS) feature into the MCV chart. Adaptive VSS, evaluated through metrics like median run length (MRL) and expected median run length (EMRL), is also integrated for MCV monitoring. In contrast to earlier studies that predominantly focused on average run length (ARL), this research acknowledges the potential inaccuracies in ARL measurement. In this study, two optimal designs for VSS MCV charts are formulated by minimizing two criteria: firstly, MRL; and secondly, EMRL, both accounting for deterministic and unknown shift sizes. Additionally, to assess the distribution's variability in run lengths, the study provides the 5th and 95th percentiles. The research delves into two VSS schemes: one with a defined small sample size (nS), and another with a predetermined large sample size (nL) for the initial subgroup (n(1)). The approach taken involves the development of a Markov chain method for designing and deriving performance measures of the proposed chart. These measures include MRL and EMRL. Moreover, a comparative analysis between the proposed chart's performance and the standard MCV chart (STD) is presented in terms of MRL and EMRL criteria. The outcomes illustrate the superiority of the proposed chart over the STD MCV chart for all shift sizes, whether they are upward or downward, and when n(1) equals nS or nL.
      PubDate: 2023-12-13
      Issue No: Vol. 15, No. 2 (2023)
       
  • Proximate Composition, Phytochemical and Antimicrobial Activities of The
           Fermented Ripe Fruit of Musa Paradisiaca

    • Authors: Mansurat Bolanle Falana, Quadri Olaide Nurudeen
      Pages: 81 - 90
      Abstract: Fermentation alters the physical and chemical components of foods by enhancing their nutrients and synthesizing bioactive composition. To determine the impact of fermentation, ripe Musa paradisiaca (Plantain) fruit used as food and medicine across the globe was fermented and analyzed for pH, proximate composition, preliminary phytochemical constituents, in vitro antimicrobial activities, and active constituents by High-Performance Liquid Chromatography (HPLC). The pH of the sample dropped from 6.7 to 4.7 during fermentation while alkaloids, flavonoids, glycosides, saponins, steroids, tannins, and terpenoids were recorded. Moisture (7.84%), ash (2.10%), fat (7.28%), carbohydrate (86.4%), fiber (1.42%), and protein (2.24%) were present. Bactericidal (12.5-50.0 mg/mL against Staphylococcus aureus and Escherichia coli, respectively) and fungicidal activities (12.5-25.0 mg/mL against Candida albicans) were noted. At 25, 50, and 100 mg/mL sample concentrations, diameters of 7.00 mm, 10.00 mm, and 16.00 mm were recorded against C. albicans, E. coli, and S. aureus. Capsaicin, caffeic acid, beta-sitosterol, kaempferol, apigenin, syringin, quercetin, and luteolin were detected by HPLC. Consequently, the fermented ripe fruits of M. paradisiaca harbours active constituents and exhibit antimicrobial activities making them curative against pathogens.
      PubDate: 2023-12-13
      Issue No: Vol. 15, No. 2 (2023)
       
  • DFT Investigation of CH4 and H2O Adsorption on Pd (111), Ni (111), Pt
           (111), and Ir(111) Surfaces

    • Authors: Abdulrauf Onimisi Ibrahim, Baba Jibril El-Yakubu
      Pages: 91 - 100
      Abstract: Using density functional theory (DFT) calculations, the surface Gibbs free energy of methane and water adsorption on Pt(111), Ir(111), Ni(111), and Pd(111) surfaces was investigated. DFT computations were employed to investigate the adsorption of methane and water molecule on unit cells with varying coverage levels of 0.11, 0.25, 0.50, and 1.00 monolayers and the aggregation of H2O over clean transition metal surfaces. The adsorption configuration was assessed to experimental findings to evaluate our computational approaches' accuracy and reliability. A thermodynamic diagram was constructed for exploring the adsorption of CH4 and H2O on metal surfaces. The order of the methane adsorption energies on different metal surfaces is as follows: Pd(111) > Pt(111) > Ni(111) > Ir(111). A more significant number of H2O molecules on the transition metal surfaces reduces the contact between the metal surfaces and water molecules during water aggregation. The thermodynamic stability of water and methane adsorption coverage was found to be best on the Pt(111) surface.
      PubDate: 2023-12-13
      Issue No: Vol. 15, No. 2 (2023)
       
  • The Usage of Banana Peels and Soybean Hull for the Treatment of Lake
           Water: Turbidity and Total Suspended Solids

    • Authors: Nur Shahirah Mohd Aripen, Norhazimah Abdul Halim, Sabrina Saadon, Nur Danisya Akma Jamil
      Pages: 1 - 6
      Abstract: Lake water get contaminate due to the growth of population and modernization which can causing problems. Therefore, it is crucial for wastewater to go through wastewater treatment to improves the quality of water. One of the processes involved is coagulation process. Chemical coagulants may have an adverse effect on the consumer and the environment. The use of natural coagulants can be a secure replacement for chemical coagulants. Hence, this study was conducted to reduce the usage of chemicals in the coagulation process by using natural coagulant of banana peels and soybean hulls. The main aim of this study is to investigate the effect of natural coagulant for wastewater treatment of lake water. Banana peels and soybean hulls were the main materials in making a plant-based coagulant by drying, grinding, and sieving. Jar test was carried out to investigate the effectiveness of natural coagulant by determining their turbidity and total suspended solids. It was found that banana peels perform effectively at a dosage of 400mg/L with turbidity removal achieved is almost 50%. On the other hand, soybean hulls work effectively at a dosage of 600mg/L with turbidity removal achieved is 54%. Based on the result, it is shown that using banana peels as a natural coagulant has effectively reduced the turbidity and total suspended solids of lake water with the optimum number of dosages of 600mg/L.
      Keywords: Articles ; The Photocatalytic Activity of Green Zinc Oxide Nanoparticles in The
             Treatment of Aerobically Palm Oil Mill Effluent

      • Authors: Dilaeleyana Abu Bakar Sidik, Nur Hanis Hayati Hairom, Aniq Ikhmal Rozman, Mohamad Jauhar Shaqili Johari, Aida Muhammad
        Pages: 7 - 15
        Abstract: Traditional treatment of aerobically palm oil mill effluent (A-POME) is incapable of removing the colour and organic load that does not exceed the discharge standard limit to the stream channel. Green synthesis nanoparticles (NPs) provide a significant potential for substantial performance in the photocatalytic degradation of high-strength wastewater. Therefore, the current project's goal is to investigate the photocatalytic degradation performance of A-POME in the addition of green Zinc Oxide Cymbopogon Citratus (ZnO–CC) NPs in terms of chemical oxygen demand (COD), turbidity, and colour removal. The outcomes showed that pH 8 and a ZnO-CC NPs loading of 0.3g/L was ideal for the photocatalytic degradation of A-POME with a significant percentage reduction of turbidity (68.03%), colour (48.11%), and COD (75.4%). The equilibrium data revealed a better fit Langmuir-Hinshelwood models with higher R2 and K values of 0.9906 and 0.0225, respectively. Increased ZnO–CC NPs loading in alkaline medium aided in the breakdown of A-POME pollutants by increasing the surface area accessible for UV light adsorption during the photocatalytic process. Thus, the finding from this study can assist the palm oil mill sector in improving A-POME treatment to provide high-quality treated effluent.
        Keywords: Articles ; The Economics of Network Reconfiguration and Shunt Compensation on a 33 kV
               Distribution Network

        • Authors: Muyideen Lawal, Abdulsemiu Olawuyi, Kayode Awomolo, Abdulrasaq Jimoh
          Pages: 16 - 28
          Abstract: This work studies the cost benefits derivable from network reconfiguration and shunt compensation of a Nigerian 33 kV distribution network. The approach adopted requires that the base case power flow analysis of the distribution network was first carried out, after which a shunt capacitor was used for compensation. The introduction of a tie-line in the network and a combination of capacitor and tie-line on same network were also carried out. The costs analysis of compensation and reconfiguration was carried out to understand their financial worthiness. The results obtained showed that the payback period (PP) for the introduction of compensation only, reconfiguration only and combination of compensation and reconfiguration are 1286.89 hr, 328.58 hr and 1043.31 hr, respectively. Though, reconfiguration only gives the least PP, a combination of compensation and reconfiguration has a long time cost benefit. At time above 5147.57 hr, it generates more profit than others.
          Keywords: Articles ; Application of Exponentially Fitted Collocation Algorithm for Solving
                 nth-Order Fredholm Integrodifferential Equations

          • Authors: Falade Kazeem Iyanda, Taiwo Omotayo Adebayo
            Pages: 29 - 42
            Abstract: In this paper, we seek to build and apply an exponentially fitted collocation algorithm (EFCA) for the solutions of nth-order Fredholm type integrodifferential equations. For this purpose, an EFCA was formulated and applied to solve four examples from the literature. Numerical experiment was performed and the results were compared with the exact solutions, and some existing methods. From the four examples considered, the results obtained showed that the proposed algorithm is fast, efficient, and reliable.
            Keywords: Articles ; Wind Characteristics and Potentials of Two-Parameter Weibull Distribution
                   and Maximum Entropy-Based Distribution Functions at an Equatorial Location
                   

            • Authors: Taofeek Otunla, Abasikeme Kenneth Umoren
              Pages: 40 - 51
              Abstract: Thorough knowledge of the wind characteristics and variations are of great importance in the development of wind energy resource in any location. This study examines the wind characteristics and assess the potential of two distribution functions in a low wind equatorial region of West Africa. High resolution wind speed and direction data were obtained from a site in Nsukka, a location chosen in the region of study. Diurnal, seasonal and annual variations of both the wind speed and directions were examined. The potentials of two-parameter Weibull distribution and another distribution function based on Maximum Entropy principle (MEP) were assessed using R2 and root mean squared error (RMSE). The results indicated that day-time is windier than night-time. The transitions months of February, March and April have the highest wind speed. The dry season has greater energy potential than rainy season. The predominant wind direction lay within the sectors: South-South-West and East. The predominant wind sector for February, March and April is South-East. The R2 for daily, sub-seasonal day-time and night-time, monthly, and annual ranged between 0.90 and 0.99 for both MEP-based and Weibull distributions. The daily, sub-seasonal day-time and night-time, monthly, and annual RMSE also ranged between 0.011 to 0.075 for MEP-based and Weibull distribution respectively. Thus, both MEP-based and Weibull two-parameter distribution functions can be used to model wind data at the location of study.
              Keywords: Articles ; Rheological Study of Formate (Nacl) and Ethylene Glycol Based Drilling
                     Fluid Using MATLAB

              • Authors: Bilal Sabiu, Abdurrazak Ayobami Bello, Habib Adebisi Abubakar
                Pages: 43 - 50
                Abstract: Non-Newtonian models are used in describing the rheology of drilling fluids. Models, such as Power Law, Bingham Plastic, and the Hershel-Buckley model are used to predict drilling fluid behaviour. Selection of the best rheological model that accurately represents the shear stress-shear rate data is optimal in determining fluid use and predicting realistic rheological behaviour. This research is aimed at studying the best rheology model to fit collected data from sodium chloride (NaCl) and ethylene glycol (EG) based drilling fluid. The assessment utilized a total of ten sets of experimental viscometry data from laboratory-formulated drilling fluid samples A to J with the varying volume of formate sodium chloride (NaCl) and ethylene glycol (EG). Using Equations relating shear rates to shear stress, MATLAB non-linear regression approach was used to determine the best of the three rheological models to fit the experimental. The Root square (R2), Adjusted Root square (Adj R2), and Root Mean Square Error (RMSE) were used in determining the goodness of fit and degree of deviation of the experimental data. data. High concentrations of both NaCl and ethylene glycols in the formulation provide a better shear rate shear stress fit. Although the ethylene glycol presence may have account for the improved fit, as Sample E, F and G despite containing high volume of the formate NaCl, the data where not effectively fitted by the models. From the results, the power law model was the least suitable with an R2 value of 0.881-0.956, Adj R2 83-96%, and a poor RSME in the range 2-9. The Herschel-Bulkley model showed an improved fit for the fluids with an R2 0.897-0.973, Adj R2 87- 98%, and a better RSME <3. this model also shows a good shear thinning behaviour from its three parameter consistency (n) index values. The Bingham plastic model best fits the rheology of the drilling fluid data R2 0.93-0.99, Adj R2 93-98%, and RSME of <2.
                Keywords: Articles ; Application of Backward Differentiation Formula on Fourth-Order
                       Differential Equations

                • Authors: Khadeejah James Audu , Jamiu Garba, Abdgafar Tunde Tiamiyu, Blessing Ashiodime Thomas
                  Pages: 52 - 65
                  Abstract: Higher order ordinary differential equations are typically encountered in engineering, physical science, biological sciences, and numerous other fields. The analytical solution of the majority of engineering problems involving higher-order ordinary differential equations is not a simple task. Various numerical techniques have been proposed for higher-order initial value problems (IVP), but a higher degree of precision is still required. In this paper, we propose a novel two-step backward differentiation formula in the class of linear multistep schemes with a higher order of accuracy for solving ordinary differential equations of the fourth order. The proposed method was created by combining interpolation and collocation techniques with the use of power series as the basis function at some grid and off-grid locations to generate a hybrid continuous two-step technique. The method's fundamental properties, such as order, zero stability, error constant, consistency, and convergence, were explored, and the analysis showed that it is zero stable, consistent and convergent. The developed method is suitable for numerically integrating linear and nonlinear differential equations of the fourth order. Four Numerical tests are presented to demonstrate the efficiency and accuracy of the proposed scheme in comparison to some existing block methods. Based on what has been observed, the numerical results indicate that the proposed scheme is a superior method for estimating fourth-order problems than the method previously employed, confirming its convergence.
                  Keywords: Articles ;
                   
                  JournalTOCs
                  School of Mathematical and Computer Sciences
                  Heriot-Watt University
                  Edinburgh, EH14 4AS, UK
                  Email: journaltocs@hw.ac.uk
                  Tel: +00 44 (0)131 4513762
                   


                  Your IP address: 44.210.149.205
                   
                  Home (Search)
                  API
                  About JournalTOCs
                  News (blog, publications)
                  JournalTOCs on Twitter   JournalTOCs on Facebook

                  JournalTOCs © 2009-
JournalTOCs
 
 

 A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z  

  Subjects -> SCIENCES: COMPREHENSIVE WORKS (Total: 374 journals)
The end of the list has been reached or no journals were found for your choice.
Similar Journals
Similar Journals
HOME > Browse the 73 Subjects covered by JournalTOCs  
SubjectTotal Journals
 
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
 


Your IP address: 44.210.149.205
 
Home (Search)
API
About JournalTOCs
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-