gazi university journal of science最新文献

{"title":"Locational Characteristics and Impact of Attenda Abattoir, Ogbomoso, Nigeria","authors":"S. Olanrewaju, Fadila Garba, Yetunde Babayemi̇","doi":"10.35378/gujs.964138","DOIUrl":"https://doi.org/10.35378/gujs.964138","url":null,"abstract":"The study examined the locational characteristics and impacts of attenda abattoir, Ogbomoso town, Oyo state, Nigeria. This is with a view to proffering recommendations that will aid the achievement of sustainable development in the area. To achieve this, a ring of 100 meter radius was delineated around the abattoir, and a landuse inventory was done. Thereafter, observation and measurement was done daily in the abattoir for a month, excluding Sundays that operations were not carried. Observations made include daily numbers of cow killed, the volume of wastewater utilised in the slaughter slab, and characteristics of the semisolid waste disposed daily. To assess the impact of the abattoir, water samples were obtained from point of discharged (POD) of waste water to the stream, 30 meters, 60 meters and 90 meters on the course of the stream. Also samples were obtained from a well each, found within 30 meters, 60 meters, and 90 meters from the abattoir. The obtained water samples were tested for pH, Conductivity, Lead, Dissolved Oxygen, Cadmium, and bacterial content such as salmonella sp. and E.coli, using the procedure of Magaji and Chup, (2012). Obtained data were subjected to descriptive statistics such as frequency count and percentage. Tables were also used to summarise data. The closest landuse to the abattoir is a 40 km stream with the setback of 2.6 meters. This setback is used as waste dump. In the abattoir, an average of 19 cows are killed daily. For this operation, an average of 1153.7 litres of wastewater is generated and discharged into the nearby stream. Hence the pH value of the stream is 5.20, 5.35, 5.41 and 5.40 respectively at POD, 30 meter, 60 meters and 90 meters respectively. Also, the concentration of Lead (Fe2+) in water samples is higher than FEPA limits of 0.01mg/l. The study recommends relocation of abattoir, urban renewal of abattoir area, and encouragement of residents and butchers to visit hospital for medical checkups. The study therefore concludes that sustainable environmental management cannot be achieved without effective landuse planning.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43161121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Classes of Population Mean Estimators using Transformed Variables in Double Sampling","authors":"Natthapat Thongsak, Nuanpan Lawson","doi":"10.35378/gujs.1056453","DOIUrl":"https://doi.org/10.35378/gujs.1056453","url":null,"abstract":"Transformation techniques have been used to increase the efficiency of estimators in sample surveys. In this paper, some classes of population mean estimators using transformation on an auxiliary variable and on both the auxiliary and study variables have been proposed under double sampling. We obtain the biases and mean square errors of the proposed estimators up to the first order of approximation. A simulation study and application to a rubber production dataset have been used to illustrate the performance of the proposed estimators. The results show that the proposed estimators perform much better than other existing estimators under given conditions.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46647882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of Sinterability of WC-Co component comprising of AISI 4340 Steel Inserts","authors":"M. Subaşı, Harun Kocak, A. Safarian, C. Karatas","doi":"10.35378/gujs.1070501","DOIUrl":"https://doi.org/10.35378/gujs.1070501","url":null,"abstract":"In this study, sinterability of WC-9% Co component with AISI 4340 steel insert was investigated using Inserted Powder Injection Molding (IPIM) method. Sintering experiments were performed at temperatures of 1200 °C to 1350 °C with dwell times of 120, 240, 360 min. Defects such as gaps, cracks and macro-porosities were observed in specimens, sintered at temperatures of 1200 °C and 1250 °C for all dwell times. It was proved that sintering temperature of 1350 °C was as high as it caused insert to get deformed and melted. As a result, the optimum sintering temperature and dwell time were determined to be 1300 °C and 240 min, respectively, at which the highest hardness, compression strength, and sintered density were obtained without any defects such as cracks or gaps.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47338483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of pressure on electronic, mechanical, and dynamic properties for orthorhombic WP","authors":"C. Tayran, M. Çakmak","doi":"10.35378/gujs.1122891","DOIUrl":"https://doi.org/10.35378/gujs.1122891","url":null,"abstract":"The structural, mechanical, electronic, and dynamic features of MnP-type WP have been presented under 0-50 GPa hydrostatic pressure utilizing density functional theory. The lattice constants, values of volume, and bond lengths are decreased with increasing pressure. It is found that the results of electronic band structures show that WP preserves its metallic feature under the pressure. The electronic band structures are shifted up in Y–Γ and Γ–X symmetry points under pressure. The partial density of the states indicates that hybridization occurs between W-d and P-p orbitals and also W–d orbital is dominated at all pressures. It is obtained that the mechanical properties of WP are increased with the increasing pressure. Additionally, the WP becomes more ductile under pressure. According to phonon dispersions, it is investigated that WP is dynamically stable under pressure.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42547743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An Adaptive Time Filtered Backward Euler Method for Reduced-Order Models of Incompressible Flows","authors":"Fatma GÜLER EROĞLU","doi":"10.35378/gujs.904961","DOIUrl":"https://doi.org/10.35378/gujs.904961","url":null,"abstract":"This paper studies a reduced-order model based on proper orthogonal decomposition (POD) for the incompressible Navier-Stokes equations. The difficulties resulting from nonlinearity are eliminated using the variational multiscale (VMS) method. The time filter is added as a separate post-processing step to the standard VMS-POD approximation. This increases the accuracy and presents a better energy preserving scheme without adding additional computational complexity. Theoretical analyses of the method are given. Numerical experiments are presented to verify the theoretical findings.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46722405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Class of Demi-Order Norm Continuous Operators","authors":"Gül Sinem Keleş, B. Altın","doi":"10.35378/gujs.1098503","DOIUrl":"https://doi.org/10.35378/gujs.1098503","url":null,"abstract":"In this paper, we introduce the class of demi-order norm continuous operators on a Banach lattice. We study the relationship between order-to-norm continuous operators and demi-order norm continuous operators. We also investigate some properties of the class of demi-order norm continuous operators, and it is given a characterization of a Banach lattice with order continuous by the term of the demi-order norm continuous operators.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42754933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Comprehensive Review of Feature Selection and Feature Selection Stability in Machine Learning","authors":"Mustafa Büyükkeçeci̇, M. C. Okur","doi":"10.35378/gujs.993763","DOIUrl":"https://doi.org/10.35378/gujs.993763","url":null,"abstract":"Feature selection is a data preprocessing method used to reduce the number of features in the datasets. Feature selection techniques search the entire feature space to find an optimal feature set that is free of redundant and irrelevant features. Reducing the dimensionality of a dataset by removing redundant and irrelevant features has a pivotal role in improving the performance, i.e., accuracy, of inductive learners and building simple models. Thus, feature selection is an imperative task of machine learning. The apparent need for feature selection raised considerable interest and became an important research topic in a wide range of fields, including bioinformatics, text classification, image recognition, and computer vision. As a result, a large pool of feature selection methods has been proposed, and a considerable amount of literature has been published on feature selection. The quality of feature selection algorithms is measured not only by the performance of the features they prefer but also by their stability. Therefore, this study focuses on two topics: feature selection and feature selection stability. In the pages that follow, general concepts and methods of feature selection are discussed and then an overview of feature selection stability and stability measures are given.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45172651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A literature review: Wind energy within the scope of MCDM methods","authors":"Özer Eroğlu, Ezgi AKTAŞ POTUR, M. Kabak, Cevriye Gencer","doi":"10.35378/gujs.1090337","DOIUrl":"https://doi.org/10.35378/gujs.1090337","url":null,"abstract":"Renewable energy sources are vital for environmental sustainability. With the damage of fossil fuels to nature and the depletion of fossil fuels over time, energy production from clean and inexhaustible renewable energy sources has become widespread. Wind energy, one of the renewable energy sources, is a clean energy source that does not emit any harmful waste to the environment. Wind energy is a low-cost energy source that is mostly used for electricity generation. Criteria such as wind speed, turbine structure, and the characteristics of the areas where the wind turbines will be located are effective on the amount of energy to be produced. In this study, a comprehensive review of the studies using MCDM methods related to wind energy is made. In the manner of the statistical data obtained from the 97 studies examined, it has been observed that the wind energy investments of the countries and the scientific publications made in these countries do not progress linearly with each other. The fact that countries have different wind energy potentials and the difference in the countries' interest in renewable energy sources is thought to be effective in this regard. While there are articles in the literature in which studies on renewable energy sources are discussed together with MCDM methods, there is no comprehensive review study in which wind energy and MCDM methods are discussed together. According to our best knowledge, this is the first study to comprehensively evaluate wind energy studies in terms of multi-criteria decision-making methods. With this study, a framework has been presented for subsequent studies on the application of MCDM methods in wind energy.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42044956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ascorbic Acid Enhances the Metabolic Activity, Growth and Collagen Production of Human Dermal Fibroblasts Growing in Three-dimensional (3D) Culture","authors":"Serkan Dikici","doi":"10.35378/gujs.1040277","DOIUrl":"https://doi.org/10.35378/gujs.1040277","url":null,"abstract":"Tissue engineering (TE) enables developing functional synthetic substitutes to be replaced with damaged tissues and organs instead of the use of auto or allografts. A wide range of biomaterials is currently in use as TE scaffolds. Among these materials, naturally-sourced ones are favourable due to being highly biocompatible and supporting cell growth and function whereas synthetic ones are advantageous because of the high tunability on mechanical and physical properties as well as being easy to process. Alongside the advantages of synthetic polymers, they mostly show hydrophobic behaviour that limits biomaterial-cell interaction and consequently the functioning of the developed TE constructs. In this study, we assessed the impact of L-Ascorbic acid 2-phosphate (AA2P) on improving the culture of human dermal fibroblasts (HDFs) growing on a three-dimensional (3D) scaffold made of polycaprolactone by emulsion templating technique. Our results demonstrated that AA2P enhances the metabolic activity, growth, and collagen production of HDFs when supplemented to their growth medium at 50 µg/mL concentration. It showed a great potential to be used as a growth medium supplement to circumvent the disadvantages of culturing human cells on a synthetic biomaterial that is not favoured in default. AA2P's potential to improve cell growth and collagen deposition may prove an effective way to culture human cells on 3D PCL PolyHIPE scaffolds for various TE applications.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46138010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Natural Language Processing Challenges and Issues: A Literature Review","authors":"Abdul Ahad Abro, Mir Sajjad Hussain Talpur, A. Jumani","doi":"10.35378/gujs.1032517","DOIUrl":"https://doi.org/10.35378/gujs.1032517","url":null,"abstract":"Natural Language Processing (NLP) is the computerized approach to analysing text using both structured and unstructured data. NLP is a simple, empirically powerful, and reliable approach. It achieves state-of-the-art performance in language processing tasks like Semantic Search (SS), Machine Translation (MT), Text Summarization (TS), Sentiment Analyser (SA), Named Entity Recognition (NER) and Emotion Detection (ED). NLP is expected to be the technology of the future, based on current technology deployment and adoption. The primary question is: What does NLP have to offer in terms of reality, and what are the prospects? There are several problems to be addressed with this developing method, as it must be compatible with future technology. In this paper, the benefits, challenges and limitations of this innovative paradigm along with the areas open to do research are shown.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49537754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}