gazi university journal of science最新文献

{"title":"Radioactivation Measurement of a Protective Collimator and Comparisons with Simulation After METU-Defocusing Beamline Pretest Irradiation","authors":"B. Demirköz, P. Uslu Kiçeci, S. Uzun Duran","doi":"10.35378/gujs.1018518","DOIUrl":"https://doi.org/10.35378/gujs.1018518","url":null,"abstract":"Electronic components must be tested to allow for safe and reliable missions in radiation environments. The METU Defocusing Beamline (METU-DBL) was installed in the R&D room at the Particle Accelerator Facility (PAF) of Turkey Energy, Nuclear and Mining Research Institute (TENMRI) to perform proton irradiation tests for these electronic components in accordance with the ESA (European Space Agency) ESCC (European Space Components Coordination) No:25100 standard. METU-DBL uses beam elements such as quadrupole magnets and collimators to enlarge the beam and decrease the flux respectively for the specifications of the standard. A pretest setup was constructed and this system was operated for a total of 17 hours for three months before the METU-DBL final design was assembled. The first protective collimator is made of stainless steel 316L and was used during the period of pretests. As a result of these irradiations, the emerged radioisotopes in the collimator were observed and measured insitu with a NaI detector. These measurements were compared with the FLUKA simulations 120 days after the last irradiation. Among fourteen radioisotopes, only six of them with activity above 1.0×101 Bq/cm3 were matched.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49092827","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":"BOOTSTRAP APPROACH FOR TESTING MORE THAN TWO POPULATION MEANS WITH RANKED SET SAMPLING","authors":"Nurdan YENİAY KOÇER, Y. Özdemir, F. Gökpınar","doi":"10.35378/gujs.1038212","DOIUrl":"https://doi.org/10.35378/gujs.1038212","url":null,"abstract":"In this study, hypothesis test is investigated based on Bootstrap sample selection methods to compare more than two population means under Ranked Set Sampling. Bootstrap sample selection methods are obtained by adapting Hui’s sample selection methods for confidence interval. We also compare these adapted methods with their alternatives using simulation study. Simulation study shows that adapted methods which proposed in this paper perform quite well.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41248517","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":"Phytochemical Screening and Antibacterial Activity of Lignosus rhinocerotis (Cooke) Ryvarden Grown in Open Field and Indoor","authors":"Nurkhalida Kamal, Hazniza Adnan, J. Latip","doi":"10.35378/gujs.995742","DOIUrl":"https://doi.org/10.35378/gujs.995742","url":null,"abstract":"Lignosus rhinocerotis (Cooke) Ryvarden, known as tiger milk mushroom, is a rare and valuable medicinal mushroom that is widely used throughout Southeast Asia and South China for treating several ailments. This study was conducted to screen the phytochemicals present in L. rhinocerotis (Cooke) Ryvarden sclerotium grown from two different environments, open field and indoor, and evaluate the antibacterial activity. In this study, phytochemical screening of ethyl acetate and methanolic extract of L. rhinocerotis (Cooke) Ryvarden sclerotium were done using various chemical tests to identify the compounds present in the extracts. All the extracts were then tested for antibacterial activity against three different bacteria including Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa at the concentrations of 20 and 30 mg/mL using disc diffusion method. Based on the phytochemical screening result, extracts of L. rhinocerotis (Cooke) Ryvarden demonstrated the presence of steroids, terpenoids, alkaloids, and flavonoids. The antibacterial assays revealed that the ethyl acetate extracts from open field and indoor cultivations exhibited moderate activities against S. aureus at 30 mg/mL with the values of the inhibition zone being 13.3 ± 0.67 mm and 11.0 ± 0.58 mm, respectively.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41519939","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 study on QSAR and relations between molecular descriptors of 5, 8-quinoline quinones derivatives","authors":"Y. Gülseven Sıdır, İ. Sıdır","doi":"10.35378/gujs.1051216","DOIUrl":"https://doi.org/10.35378/gujs.1051216","url":null,"abstract":"Abstract \u0000In this study, some electronic, hydrophobic and thermochemical parameters of 28 different 5,8-quinolinequinone derivatives having diverse substituents have been calculated by using DFT (B3LYP)/6-31G(d, p) method and basis set. Relationships between different molecular descriptors have been studied by using molecular polarizability (α), dipole moment (μ), EHOMO, ELUMO, molecular volume (Vm), ionization potential (IP), electron affinity (EA), electronegativity (χ), molecular hardness (η), molecular softness (S), electrophilic index (ω), molar refractivity (MR), octanol–water partition coefficient (log P), thermochemical properties (entropy (Se), capacity of heat (C)); as to investigate activity relationships with molecular structure. In addition, the QSAR/QSPR between molecular properties and biological activity (anti-proliferative and anti-inflammatory activity) has been investigated, where R, R2, F, P and RMSE have taken into account in order to find a statistically correct model in QSAR studies. The dependence of the electronegativity parameter on both electronic and thermochemical parameters is found to be the most correlated parameter.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46126693","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":"Robust Spoofed Speech Detection with Denoised I-vectors","authors":"Gökay Dişken","doi":"10.35378/gujs.1062788","DOIUrl":"https://doi.org/10.35378/gujs.1062788","url":null,"abstract":"Spoofed speech detection is recently gaining attention of the researchers as speaker verification is shown to be vulnerable to spoofing attacks such as voice conversion, speech synthesis, replay, and impersonation. Although various different methods have been proposed to detect spoofed speech, their performances decrease dramatically under the mismatched conditions due to the additive or reverberant noises. Conventional speech enhancement methods fail to recover the performance gap, hence more advanced techniques seem to be necessary to solve the noisy spoofed speech detection problem. In this work, Denoising Autoencoder (DAE) is used to obtain clean estimates of i-vectors from their noisy versions. ASVspoof 2015 database is used in the experiments with five different noise types, added to the original utterances at 0, 10, and 20 dB signal-to-noise ratios (SNR). The experimental results verified that the DAE provides a more robust spoof detection, where the conventional methods fail.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45933787","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":"Alternative Support Material to Platinum Catalyst Used for Oxygen Reduction Reaction: Nonporous Carbon","authors":"Ayşenur Öztürk, Ayşe Bayrakçeken","doi":"10.35378/gujs.1054803","DOIUrl":"https://doi.org/10.35378/gujs.1054803","url":null,"abstract":"In this study, unlike the porous carbon as a conventional catalyst support material in fuel cells, nonporous carbon was synthesized in the presence of different acid concentrations (0.2 M-1 M) and investigated as a support material for platinum (Pt) catalysts in the oxygen reduction reaction (ORR). Since the micropore volume of the synthesized carbons is negligible, the detected surface areas with Brunauer-Emmett-Teller (BET) method were in the range of 19-23 m2/g. Among the support materials, the carbon-supported Pt catalyst synthesized in the presence of 1 M acid was investigated electrochemically in terms of hydrogen oxidation (HOR) and ORR half-cell reactions in the three-electrode system. The Pt catalyst supported with nonporous carbon, synthesized using 1 M acid, reached the maximum limiting current value of -0.25 mA/cm2 (@2500 rpm) at ORR hydrodynamic curves. Low internal and charge transfer resistances of the same catalyst in electrochemical impedance spectroscopy (EIS) analysis are attributable to its nonporous structure.","PeriodicalId":12615,"journal":{"name":"gazi university journal of science","volume":null,"pages":null},"PeriodicalIF":0.9,"publicationDate":"2022-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48672090","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":"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":null,"pages":null},"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":null,"pages":null},"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":null,"pages":null},"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":null,"pages":null},"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}