Osmaniye Korkut Ata University

About: Osmaniye Korkut Ata University is a education organization based out in Osmaniye, Turkey. It is known for research contribution in the topics: Catalysis & Neutron. The organization has 341 authors who have published 869 publications receiving 8259 citations.

Development of an Artificial Neural Network Model for the Prediction of the Performance of a Silica-gel Desiccant Wheel

Abstract: This work presents mathematical equations derived from Artificial Neural Networks (ANNs) for the estimation of dry bulb temperature and specific humidity at the outlet of a desiccant wheel to predict useful data for designers and engineers. The neural network model comprises five inputs and two output neurons that define the outlet conditions (dry bulb temperature and specific humidity) of a desiccant wheel. The results obtained by the ANN model are compared with the actual data by using input variables. The results show that the mean absolute percentage errors for dry bulb temperature and specific humidity are found to be 0.80% and 1.56% respectively; and the correlation coefficient (R) values obtained are approximately 0.986 for both output variables. The root mean square errors, which is another significant point in this study, are found to be 0.54% and 0.18% for dry bulb temperature and specific humidity respectively.

A Novel Parametric Model for the Prediction and Analysis of the COVID-19 Casualties

Abstract: Coronavirus disease (COVID-19) outbreak has affected billions of people, where millions of them have been infected and thousands of them have lost their lives. In addition, to constraint the spread of the virus, economies have been shut down, curfews and restrictions have interrupted the social lives. Currently, the key question in minds is the future impacts of the virus on the people. It is a fact that the parametric modelling and analyses of the pandemic viruses are able to provide crucial information about the character and also future behaviour of the viruses. This paper initially reviews and analyses the Susceptible-Infected-Recovered (SIR) model, which is extensively considered for the estimation of the COVID-19 casualties. Then, this paper introduces a novel comprehensive higher-order, multi-dimensional, strongly coupled, and parametric Suspicious-Infected-Death (SpID) model. The mathematical analysis results performed by using the casualties in Turkey show that the COVID-19 dynamics are inside the slightly oscillatory, stable (bounded) region, although some of the dynamics are close to the instability region (unbounded). However, analysis with the data just after lifting the restrictions reveals that the dynamics of the COVID-19 are moderately unstable, which would blow up if no actions are taken. The developed model estimates that the number of the infected and death individuals will converge zero around 300 days whereas the number of the suspicious individuals will require about a thousand days to be minimized under the current conditions. Even though the developed model is used to estimate the casualties in Turkey, it can be easily trained with the data from the other countries and used for the estimation of the corresponding COVID-19 casualties.

Characterization of phenolic compounds in sweet lime (Citrus limetta) peel and freshly squeezed juices by LC-DAD-ESI-MS/MS and their antioxidant activity

Abstract: Sweet lime (Citrus limetta) is one of the citrus species and it is generally consumed fresh or processed to fruit juice. The squeezing method of fruit is an important factor affecting the quantity and composition of phenolic compounds of the juice. The aim of this study was to identify and quantify the phenolic compounds and determine the antioxidant activities of sweet lime peel and juices. For this purpose, sweet lime juices were prepared using two different methods. Firstly, sweet lime fruits were hand-squeezed without peeling. Secondly, fruits were hand-squeezed after the manual removal of the peel. The phenolic compounds of the peel and the two types of juices were analyzed by LC-DAD-ESI-MS/MS. Twenty phenolic compounds were determined in all extracts, 18 of which were flavonoids and two were phenolic acids. The major compound was hesperidin both in the peel and juices. The procyanidin B dimer and luteolin were detected for the first time in sweet lime peel and juices in the present study. The amount of phenolic compounds of the peel was significantly higher than those of the juices. The total phenolic contents of the sweet lime juice increased about 13% from 444.55 to 502.54 mg/L due to the effect of the peel. The antioxidant capacity of the peel was found to be higher than those of the juices resulting from its high phenolic content.

Effect of diffusion-annealing time (0.5 h ≤ t ≤ 2 h) on the mechanical and superconducting properties of Cu-diffused bulk MgB 2 superconductors by use of experimental and different theoretical models

Abstract: This study reports the effect of different annealing time (0.5 h ≤ t ≤ 2 h) on the electrical, physical, microstructural, mechanical and superconducting properties of Cu-diffused bulk magnesium diboride (MgB2) system by means of dc resistivity, X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and microhardness measurements (H v ). The room temperature resistivity (at 300 K), critical transition (T and T ) temperature, variation of transition temperature, grain size, phase purity, lattice parameter, texturing, surface morphology, crystallinity and Vickers microhardness values of the samples are evaluated and compared with each other. The resistivity results obtained reveal that the (T and T ) values of the samples produced ascend with the enhancement in the annealing time up to 1 h beyond which these values start to reduce systematically and in fact the smallest T of 38.1 K and T of 36.2 K are observed for the sample annealed for 2 h. Similarly, the SEM micrographs display that the surface morphology, crystallinity and grain connectivity improve until a certain diffusion-annealing time (1 h), and after this point, all the properties obtained start to degrade with the increase of the annealing time. Furthermore, the peak intensities, grain sizes and lattice parameters deduced from the XRD measurements illustrate that a systematic elongation in the a and c axis lengths is detected with the annealing time until 1 h beyond which a regular contraction in the lattice parameters is observed for the samples. Likewise, the peak intensities belonging to MgB2 phase enhance with the increment of the annealing time up to 1 h after which they reduce slowly; however, a new peak belonging to Mg2Cu phase appears in the sample annealed for the duration of 2 h, confirming both the reduction of the grain size and degradation of the critical temperature. Additionally, we have focused on the microhardness measurements for the examination of the mechanical properties of the samples studied. Experimental results of microhardness measurements are estimated using the various models such as Meyer’s law, proportional sample resistance model, modified proportional sample resistance model and Hays-Kendall (HK) approach. Based on the simulation results obtained, the Hays-Kendall (HK) approach is determined as the most suitable model describing the mechanical properties of samples prepared.