Yayınlar
Koleksiyondaki öğeler
- MakaleAçık Erişim2020Scopus SJRQ3Development of a primary school teacher on the philosophy with children: An action research*
Boyraz, Celal; Türkcan, Burçin
This study aims at providing a detailed description of the ways to understand the development process of a primary school teacher on philosophy with children (PwC) approach. Action research was used as the research method since the problems determined in the current study can be iteratively solved with the development of the teacher. The study group consists of a teacher in a primary school located at the center of Bayburt, Turkey in the 2018-2019 academic year and 20 third-grade students. Qualitative data collection methods; observation, interview, field notes and diaries were used. A systematic analytical method was applied and the data were analyzed using a content analysis approach. The primary school teacher was provided with training on the PwC approach and eight action cycles were conducted regarding the implementation of this approach. Observations and interviews conducted in this process indicated that there are developments in the teacher in implementing the PwC approach and these developments positively affect some skills of the students. Based on the findings obtained in the current study, the authors made some recommendations for practice and future studies.
AtıfScopus2OpenAlex3
İncele - MakaleAçık Erişim2019Scopus SJRQ3Green synthesis of enantiopure (S)-1-(benzofuran-2-yl)ethanol by whole-cell biocatalyst
Şahin, Engin
Optically active aromatic alcohols are valuable chiral building blocks of many natural products and chiral drugs. Lactobacillus paracasei BD87E6, which was isolated from a cereal-based fermented beverage, was shown as a biocatalyst for the bioreduction of 1-(benzofuran-2-yl) ethanone to (S)-1-(benzofuran-2-yl) ethanol with highly stereoselectivity. The bioreduction conditions were optimized using L. paracasei BD87E6 to obtain high enantiomeric excess (ee) and conversion. After optimization of the bioreduction conditions, it was shown that the bioreduction of 1-(benzofuran-2-yl)ethanone was performed in mild reaction conditions. The asymmetric bioreduction of the 1-(benzofuran-2-yl)ethanone had reached 92% yield with ee of higher than 99.9% at 6.73 g of substrate. Our study gave the first example for enantiopure production of (S)-1-(benzofuran-2-yl)ethanol by a biological green method. This process is also scalable and has potential in application. In this study, a basic and novel whole-cell mediated biocatalytic method was performed for the enantiopure production of (S)-1-(benzofuran-2-yl)ethanol in the aqueous medium, which empowered the synthesis of a precious chiral intermediary process to be converted into a sophisticated molecule for drug production.
AtıfScopus32WoS30OpenAlex34
İncele - MakaleAçık Erişim2021Scopus SJRQ1Forecasting outbreak of COVID-19 in Turkey; Comparison of Box–Jenkins, Brown's exponential smoothing and long short-term memory models
Guleryuz, Didem
The new coronavirus disease (COVID-19), which first appeared in China in December 2019, has pervaded throughout the world. Because the epidemic started later in Turkey than other European countries, it has the least number of deaths according to the current data. Outbreak management in COVID-19 is of great importance for public safety and public health. For this reason, prediction models can decide the precautionary warning to control the spread of the disease. Therefore, this study aims to develop a forecasting model, considering statistical data for Turkey. Box-Jenkins Methods (ARIMA), Brown's Exponential Smoothing model and RNN-LSTM are employed. ARIMA was selected with the lowest AIC values (12.0342, -2.51411, 12.0253, 3.67729, -4.24405, and 3.66077) as the best fit for the number of total case, the growth rate of total cases, the number of new cases, the number of total death, the growth rate of total deaths and the number of new deaths, respectively. The forecast values of the number of each indicator are stable over time. In the near future, it will not show an increasing trend in the number of cases for Turkey. In addition, the pandemic will become a steady state and an increase in mortality rates will not be expected between 17–31 May. ARIMA models can be used in fresh outbreak situations to ensure health and safety. It is vital to make quick and accurate decisions on the precautions for epidemic preparedness and management, so corrective and preventive actions can be updated considering obtained values.
AtıfScopus39WoS28OpenAlex47İncele - MakaleAçık Erişim2021Scopus SJRQ4Associations between prl/rsai polymorphism and some performance traits in holstein cattle reared under organic condition
Ozdemir, M.; Sonmez, Z.; Aksakal, V.
The aim of this study was to ascertain the RsaI polymorphism of the Prolactin (PRL) gene of 186 organically reared Holstein cattle by PCR-RFLP method, in order to reveal the genetic variation of the population, and to reveal the relationship between PRL/RsaI genotypes and some milk yield traits. In the study, the RsaI-/- genotype frequency, RsaI+/+ genotype frequency and RsaI-/+ genotype frequency of Holstein cattle were determined as 0.26, 0.22 and 0.52, respectively. The RsaI- gene frequency was 0.52, and the RsaI+ gene frequency was 0.48. Hardy-Weinberg genetic equilibrium test showed that the distribution of genotype frequencies was determined to be in genetic equilibrium. The relationships between PRL/RsaI polymorphism and the examined milk yield traits were not significant. As a result, an economic and safe method PCR-RFLP for the detection of genetic markers, was successfully used in the determination of the 3 genotypes (RsaI-/-, RsaI-/+, and RsaI+/+) of Prolactin gene in Holstein cattle reared under organic condition, and the results was similar with previously reported literature.
AtıfScopus10WoS7OpenAlex5İncele - MakaleAçık Erişim2020Scopus SJRQ2Bellevalia bayburtensis (Asparagaceae): a new species from northeastern Anatolia, Turkey
Yildirim, Hasan; Sefali, Abdurrahman
Bellevalia bayburtensis (Asparagaceae) is described and illustrated as a new species from Bayburt Province in northeastern Anatolia, Turkey. Diagnostic morphological characters, a full description, detailed illustrations, and a distribution map are provided. It is morphologically similar to B. rixii and B. paradoxa, but clearly differs from these species by the leaf shape, the bud and flower colour.
AtıfScopus6WoS5OpenAlex5İncele - MakaleYalnız künye2022Scopus SJRQ4Analysing the potential of transport triggered architecture for lattice-based cryptography algorithms
Akçay, Latif; Yalçın, Berna Örs
Lattice-based structures offer numerous possibilities for post-quantum cryptography. Recently, many post-quantum cryptography algorithms have been built on hard lattice problems. The three of the remaining four algorithms in the final round of the NIST Standardization Process rely on lattice-based methods. However, suitable processor architectures for these algorithms have not been sufficiently investigated. This study examines the potential advantages of transport triggered architecture for these algorithms. We compare popular 64-bit RISC-V processors with our conceptual transport triggered architecture processor over reference software implementations. Our processor provides better results than RISC-V competitors, regardless of the algorithm. It seems to be up to 3× faster, 1.6×–2× smaller, and consumes 1.3×–3.6× less energy than the compared RISC-V cores. Thus, an alternative base architecture is proposed for post-quantum cryptography processor development for embedded systems. The most critical shortcoming of the proposed architecture is the lack of compatible intellectual property core support for system-on-chip designs. We share comparative analyses with test results for different core configurations.
AtıfScopus3WoS2İncele - MakaleAçık Erişim2020Scopus SJRQ2Characterization of pediococcus acidilactici PFC69 and lactococcus lactis PFC77 bacteriocins and their antimicrobial activities in tarhana fermentation
Kaya, Halil İbrahim; Şimşek, Ömer
Tarhana is a traditional cereal product fermented by lactic acid bacteria (LAB) and yeast strains that has gained special interest recently as an infant nutrition. Tarhana contains wheat flour, yogurt, and various vegetables that might create a microbiological toxicological risk, especially for Bacillus cereus and Staphylococcus aureus. In this study, characterization of the metabolites responsible for antibacterial activity of Pediococcus acidilactici PFC69 and Lactococcus lactis PFC77 strains obtained from tarhana was performed, and antibacterial effects were detected against B. cereus ATCC 11778 and S. aureus ATCC 29213 during the fermentation. A total of 12,800 AU/mL antibacterial activity was observed for the supernatants of the PFC69 and PFC77 strains that were found to be stable at high temperature and in low pH conditions and sensitive to proteases, suggesting the antimicrobial metabolite is a bacteriocin. These bacteriocins were further purified and their molecular sizes were determined as 4.5 and 3.5 kDa, respectively. Importantly, inoculation of PFC69 and PFC77 to tarhana dough significantly decreased B. cereus ATCC 11778 and S. aureus ATCC 29213 amounts from the fifth day of fermentation compared to the control dough samples. P. acidilactici PFC69 and L. lactis PFC77 strains were concluded as bioprotective cultures for tarhana and these strains were offered for other cereal-based fermentations.
AtıfScopus29WoS25OpenAlex33İncele - MakaleYalnız künye2020Scopus SJRQ3An analysis of the role of the social acceptance of University Students' bicycle use in sustainable urban development when epidemics spread
Saatchian, Vahid; Azimkhani, Amin; Honari, Habib; Türkmen, Mutlu
The purpose of this study was to investigate the role of the acceptance of university students' bicycle use in sustainable urban development in Iran when epidemics spread. The research method was descriptivecorrelational, and the investigation was carried out as a field study. The statistical population of the study consisted of university students, 254 of whom were selected by a simple random sampling method to participate in the research. The research instrument was a questionnaire based on the Sustainable Development with a reliability coefficient of 0.83; the social acceptance component was based on the theory of planned behaviour with a reliability coefficient of 0.8. As the results of the investigation have demonstrated, the bicycle plays a significant role in the development of the socialization process of people, and there is a positive and significant relationship between social acceptance and sustainable development (p<0.05). Furthermore, 20% of sustainable development change was achieved through the dimensions of social acceptance (planned behaviour theory). Finally, it can be argued that perceived behaviour in social acceptance is most likely to play a significant role in the emergence of sustainable development by external factors such as encouragements and persuasion of the family, important people, friends, acquaintances, and even by the existing norms in society. Subsequently, as people change their mindset when epidemics spread, they can turn all the behaviours they manifest in their leisure time into a culture development movement.
- MakaleAçık Erişim2020Scopus SJRQ3Bio-catalytic asymmetric synthesis of β-adrenergic receptor blocker precursor: (R)-2-bromo-1-(naphthalen-2-yl)ethanol
Taşdemir, Volkan; Kalay, Erbay; Dertli, Enes; Şahin, Engin
Aromatic α-halohydrins, particularly 2-haloethanols as significant precursor of drugs, can easily be converted to chiral β-adrenergic receptor blockers. Eight strains of Lactobacillus curvatus were tested as biocatalysts for asymmetric reduction of 2-bromo-1-(naphthalen-2-yl)ethanone 1 to 2-bromo-1- (naphthalen-2-yl) ethanol 2. The parameters of the bioreduction were optimized using L. curvatus N4, the best biocatalyst found. As a result, (R)-2-bromo-1-(naphthalen-2-yl)ethanol 2, which can be β-adrenergic receptor blocker precursor, was produced for the first time in high yield and enantiomerically pure form using biocatalysts. Moreover, the gram scale synthesis was performed and 7.54 g of (R)-2 was synthesized as enantiopure form (enantiomeric excess >99%) in 48 h. The important advantages of this process are that it produces of (R)-2 for the first time in enantiopure form, in excellent yield and under environmentally friendly and moderate reaction conditions. This system is of the potential to be applied at a commercial scale.
AtıfScopus2WoS2OpenAlex2İncele - MakaleAçık Erişim2021Scopus SJRQ1A green nano-biosynthesis of selenium nanoparticles with Tarragon extract: Structural, thermal, and antimicrobial characterization
Yilmaz, Mustafa Tahsin; İspirli, Humeyra; Taylan, Osman; Dertli, Enes
In this study, tarragon extract was used as a reducing agent to perform green nano-biosynthesis of selenium nanoparticles (SeNPs). The synthesized SeNPs were characterized using measurements of UV–Vis spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy disperse analysis of X rays (EDAX), Fourier-transform infrared spectroscopy (FTIR), X-ray diffractometer (XRD) and differential scanning analysis (DSC). Synthesis of nanoparticles was confirmed by observing a peak at 212 nm in UV-VIS, indicating the surface plasmon resonance of SeNPs. Tarragon extract enabled a stable dispersion of SeNPs, giving rise to formation of the nanoparticles in the shape of quasi-spheres without clustering with the sizes between 20 and 50 nm. The SeNPs were shown to be in the form of nanocrystals, having Se embedded in the nanostructure with high thermal stability (a high resistance to thermal process over 200 °C). The SeNPs synthesized with tarragon extract could remarkably increase the inhibition zones from approximately 13 to 18 mm against the pathogenic bacteria and from 10 to 14 mm, 17–36 mm, 8–12 mm, 15–24.5 mm and 9–14 mm, against A. alternata, A. niger, A. parasiticus, B. cinerea, F. oxysporum and P. chrysogenum, respectively.
AtıfScopus86WoS71OpenAlex83İncele - MakaleAçık Erişim2022Scopus SJRQ2Anatomy, trichome micromorphology and phytochemical profile of Stachys rizeensis R.Bhattacharjee from Turkey
Gerçek, Yusuf Can; Acar Şahin, Aydan; Ecem Bayram, Nesrin; Çelik, Saffet; Sefalı, Abdurrahman; Gıdık, Betül; Cevahir Öz, Gül; Pınar, Nur Münevver
In recent years, the popularity of natural products and natural product formulations has increased due to their beneficial effects on health. As a part of this trend, Lamiaceae family members have attracted attention due to their rich bioactive properties. Although the Stachys rizeensis R.Bhattacharjee plant is an endemic plant species in Turkey, no studies focus on its characterization. Hence, the present study aims to demonstrate the anatomical, morphological and phytochemical characterization of S. rizeensis in Turkey. In the first stage of the study, anatomical and trichome morphological characterization was performed to contribute to the taxonomic definition of S. rizeensis was found to be anatomically different from some other previously studied Stachys sp. by showing lacunar collenchyma type, uncertain cambium at the corners, two or three rows of endodermis in certain areas in the stem and two rows of palisade parenchyma, capitate and peltate glandular trichomes in the leaf. In the second stage, the phenolic profile, total phenolic/flavonoid content and antioxidant activity of the plant extracts prepared using solvents with different polarities (ethanol, methanol, water, ethyl acetate and hexane) were tested to determine the phytochemical content of the plant. The phytochemical analysis supported by chemometric analysis (PCA and HCA) revealed that methanol was the most efficient organic solvent for the extraction of the phytochemical compounds of the plant. Additionally, it was observed that chlorogenic acid (1842.40–217,086.19 mg/kg), verbascoside (2591.43–204,429.81 mg/kg), luteolin (3579.56–88,636.14 mg/kg) and kaempferol (9706.30–50,340.93 mg/kg) compounds were present at maximum levels in this plant, in which 31 different phenolic compounds were scanned using LC-MS/MS. In addition, results obtained from the phytochemical analysis revealed that S. rizeensis is a valuable plant that can be used for medical protection/treatment and that it could also have a variety of culinary applications. The present study served as the first original report regarding the chemical profile and anatomical characteristics of S. rizeensis (Lamiaceae) from Turkey.
AtıfScopus4WoS4OpenAlex4İncele - MakaleYalnız künye2020Scopus SJRQ1Current–voltage analyses of Graphene-based structure onto Al2O3/p-Si using various methods
Efil, Esra; Kaymak, Nuriye; Seven, Elanur; Orhan, Elif Oz; Bayram, Ozkan; Ocak, Sema Bilge; Tataroglu, Adem
The present study's main purpose is to determine the current-voltage (I–V) performance of Graphene (Gr) based hetero nanostructure produced on Al2O3/p-Si. Graphene synthesis was carried out using the chemical vapor deposition (CVD) technique on Copper (Cu) foils used as a metal catalyst and transferred onto Al2O3/p-Si using the conventional transfer method. The I–V characteristics of this structure were measured in the dark environment, and the electrical properties of the Gr/Si structure were characterized at room temperature. The rectifying ratio (RR) of the structure was found to be about 103 at ± 3 V. The electrical properties of ideality factor (n), series resistance (Rs), and barrier height (Φb) were examined by using the theory of Thermionic Emission (TE), Norde's method, and Cheung's method. The values of Φb, which were calculated using Norde's method, Cheung's method, and the theory of thermionic emission (TE), were found to be 0.69 eV, 0.71 eV, and 0.68 eV, respectively. The ideality factor was found to be approximately 3.89 according to the theory of TE. The values of series resistance were also determined using the Norde's method and Cheung's two different parameters (dV/dln(I) and H(I)) found to be 9.60 kΩ, 9.12 kΩ, and 5.94 kΩ, respectively.
AtıfScopus25WoS25OpenAlex26İncele - MakaleAçık Erişim2021Scopus SJRQ3Land Use Impact of Maritime Pine and Eucalypt: A Life Cycle Assessment Study
Ferreira, José; Esteves, Bruno; Ayata, Ümit; Cruz-Lopes, Luisa; Domingos, Idalina
The forestry sector in Portugal faces important challenges, resulting in an increased incidence of fires and the action of pathogens, which puts the sustainability of forest resources at risk. Due to the economic, social, and environmental importance of forests, this work assessed the land use environmental impact of maritime pine and eucalypt standing in Portuguese forests. SimaPro software was used to translate the inventory table results into land use impact category. The ILCD 2011 Midpoint+ method was chosen to assess the “land use” environmental impact that focuses on soil quality and its indicator (kg carbon deficit), which describes the changes in soil organic matter associated with land interventions. The results showed that for the first rotation time, the land use impact category per cubic meter of maritime pine is 18423 kg C deficit and 23430 kg C deficit for eucalypt, which means that the land use impact category of eucalypt is 27% higher than the impact of maritime pine.
AtıfScopus2WoS1OpenAlex1İncele - MakaleAçık Erişim2019Scopus SJRQ2Modification of eutectic Al-Si alloys by Sr and CuSn5
Çolak, Murat
Enhanced properties can be achieved in Al-Si alloys by several alloying element additions. Typical modifiers are Na, Sr, and Sb that alters Si into a fibrous structure. Fluidity and mechanical properties increase as well as machinability can be improved. In this work, eutectic Al-Si alloy was modified with Al10Sr, CuSn5, and Al10Sr + CuSn5 master alloys. Microstructural characterization was carried out by optical and scanning electron microscopy. Density and hardness of the samples were measured. Wear tests were carried out. It was found that Sr modified Al12Si revealed better performance than CuSn modified.
AtıfScopus21WoS19OpenAlex21İncele - MakaleAçık Erişim2021Scopus SJRQ1Modelling of the discharge response to climate change under RCP8.5 scenario in the Alata river basin (Mersin, SE Turkey)
Yıldırım, Ümit; Güler, Cüneyt; Önol, Barış; Rode, Michael; Jomaa, Seifeddine
This study investigates the impacts of climate change on the hydrological response of a Mediterranean mesoscale catchment using a hydrological model. The effect of climate change on the discharge of the Alata River Basin in Mersin province (Turkey) was assessed under the worstcase climate change scenario (i.e., RCP8.5), using the semi-distributed, process-based hydrological model Hydrological Predictions for the Environment (HYPE). First, the model was evaluated temporally and spatially and has been shown to reproduce the measured discharge consistently. Second, the discharge was predicted under climate projections in three distinct future periods (i.e., 2021–2040, 2046–2065 and 2081–2100, reflecting the beginning, middle and end of the century, respectively). Climate change projections showed that the annual mean temperature in the Alata River Basin rises for the beginning, middle and end of the century, with about 1.35, 2.13 and 4.11 °C, respectively. Besides, the highest discharge timing seems to occur one month earlier (February instead of March) compared to the baseline period (2000–2011) in the beginning and middle of the century. The results show a decrease in precipitation and an increase in temperature in all future projections, resulting in more snowmelt and higher discharge generation in the beginning and middle of the century scenarios. However, at the end of the century, the discharge significantly decreased due to increased evapotranspiration and reduced snow depth in the upstream area. The findings of this study can help develop efficient climate change adaptation options in the Levant’s coastal areas.
AtıfScopus16OpenAlex19İncele - BildiriYalnız künye2022Scopus SJRQ2Ultrasonicate-assisted preparation of eumelanin-loaded nano/microparticles based on polylactide stereocomplex
Putri, Oceu Dwi; Petchsuk, Atitsa; Bayram, Sinan; Opaprakasit, Pakorn
The utilization of ultrasonication in the preparation of polymeric nano/microparticles has attracted vast attention due to its simplicity with low cost and high energy efficiency. The occurrence of acoustic cavitation generated by the ultrasonication process can enhance droplet disintegration, allowing the improved stability of emulsions. In this study, eumelanin-loaded nano/microparticles were prepared by employing polylactide stereocomplex (sc-PLA) formed by blending of poly(D-lactide-caprolactone-D-lactide), P(DLA-b-CL-b-DLA), triblock copolymer with linear poly(L-lactide), PLLA. The particles were prepared through an oil in water emulsion (O/W) technique followed by a solvent evaporation. The effect of ultrasonication on the encapsulation efficiency and physicochemical properties of the nano/microparticles was evaluated. The results showed that ultrasonication treatment could control nano/microparticles' shape, size, and size distribution, which enhanced the particle stability and the entrapment efficiency of eumelanin. Particle size distribution of ultrasound-assisted nano/microparticles was in a range of 0.38–135 μm, while those without ultrasonication had a broader distribution from 0.38–153 μm. Higher zeta potential was also observed in the ultrasound-assisted nano/microparticles, reflecting their higher suspension stability. The ultrasonication treatment led to higher eumelanin encapsulation efficiency (46.6%) with higher thermal stability and crystallinity, promoted by the formation of higher contents of the stereocomplex crystallites. The results confirm that ultrasonicate-assisted emulsification can be effectively used to fabricate the functional eumelanin-loaded nano/microparticles.
AtıfScopus5OpenAlex3İncele - MakaleAçık Erişim2022Scopus SJRQ1Techno-economic assessment of a synthetic fuel production facility by hydrogenation of CO2 captured from biogas
Tozlu, Alperen
In this study, a thermodynamic and economic analysis of a synthetic fuel production facility by utilizing the hydrogenation of CO2 captured from biogas is carried out. It is aimed to produce methanol, a synthetic fuel by hydrogenation of carbon dioxide. A PEM electrolyzer driven by grid-tie solar PV modules is used to supply the hydrogen need of methanol. The CO2 is captured from biogas produced in an actual wastewater treatment plant by a water washing unit which is a method of biogas purification. The required power which is generated by PV panels, in order to produce methanol, is found to be 2923 kW. Herein, the electricity consumption of 2875 kW, which is the main part of the total electricity generation, belongs to the PEM system. As a result of the study, the daily methanol production is found to be as 1674 kg. The electricity, hydrogen and methanol production costs are found to be $ 0.043 kWh−1, $ 3.156 kg−1, and $ 0.693 kg−1, respectively. Solar availability, methanol yield from the reactor, and PEM overpotentials are significant factors effecting the product cost. The results of the study presents feasible methanol production costs with reasonable investment requirements. Moreover, the efficiency of the cogeneration plant could be increased via enriching the biogas while emissions are reduced.
AtıfScopus34WoS32OpenAlex37İncele - MakaleYalnız künye2020Scopus SJRQ2Phy-X/ZeXTRa: a software for robust calculation of effective atomic numbers for photon, electron, proton, alpha particle, and carbon ion interactions
Özpolat, Ö.F.; Alım, B.; Şakar, E.; Büyükyıldız, M.; Kurudirek, M.
The purpose of the present work is robust calculation of effective atomic numbers (Zeffs) for photon, electron, proton, alpha particle and carbon ion interactions through the newly developed software, Phy-X/ZeXTRa (Zeff of materials for X-Type Radiation attenuation). A pool of total mass attenuation and energy absorption coefficients (for photons) and total mass stopping powers (for charged particles) for elements was constructed first. Then, a matrix of interaction cross sections for elements Z = 1–92 was constructed. Finally, effective atomic numbers were calculated for any material by interpolating adjacent cross sections through a linear logarithmic interpolation formula. The results for Zeff for photon interaction were compared with those calculated through Mayneord’s formula, which suggests a single-valued Zeff for any material for low-energy photons for which photoelectric absorption is the dominant interaction process. The single-valued Zeff was found to agree well with that obtained by other methods, in the low-energy region. In addition, Zeff values of various materials of biological interest were compared with those obtained experimentally at 59.54 keV. In general, the agreement between values calculated with Phy-X/ZeXTRa and Auto-Zeff and those measured were satisfactory. A comparison of Zeff values for photon energy absorption calculated with Phy-X/ZeXTRa and literature values for a nucleotide base, adenine, was made, and the relative difference (RD) in Zeff between Phy-X/ZeXTRa and literature values was found to be 2% < RD < 11%, at low photon energies (1–100 keV), while it was less than 1% at energies higher than 100 keV. Highest Zeff values were observed at low photon energies, where photoelectric absorption dominates photon interaction. For electrons, corresponding RD(%) values in Zeff were found to be in the range 0.4 ≤ RD(%) ≤ 1.7, while for heavy charged particle interactions it was 2.4 ≤ RD(%) ≤ 4.2 for total proton interaction and 0 ≤ RD(%) ≤ 8 for total alpha particle interaction. In view of the importance of Zeff for identifying and differentiating tissues in diagnostic imaging as well as for estimating accurate dose in radiotherapy and particle-beam therapy, Phy-X/ZeXTRa could be used for fast and accurate calculation of Zeff in a wide energy range for both photon and charged particle (electrons, protons, alpha particles and C ions) interactions.
AtıfScopus88WoS77OpenAlex94İncele - MakaleAçık Erişim2022Scopus SJRQ2Estimation of soil temperatures with machine learning algorithms—Giresun and Bayburt stations in Turkey
Guleryuz, Didem
Since soil temperature (ST) is one of the most critical determinants affecting the soil’s physical and chemical properties, the studies on soil temperature estimation increase with the widespread use of deep learning and machine learning algorithms. This study estimates soil temperature at four depths for Giresun and Bayburt stations in Turkey employing the Bayesian Tuned Gaussian Process Regression (BT-GPR), Bayesian Tuned Support Vector Regression (BT-SVR), and Long Short Term Memory (LSTM) models. The stations were selected from semiarid (Bayburt station) and very humid (Giresun station) climates to compare the models’ performance and measure their applicability in different climate classes. Common meteorological indicators were determined as input parameters in the developed models, and a five-and-a-half-year daily dataset was used for all models. This paper represents a novel scheme to optimize the hyperparameters of kernel functions for GPR and SVR models using the Bayesian optimization method to expand predictive efficiency. The developed GPR and SVR models’ outputs are compared with LSTM via three statistical metrics comprising the root mean square error (RMSE), mean absolute error (MAE), and the coefficient of determination (R2). The results show that the BT-GPR model has a superior estimation ability than other developed models for the two stations. The daily ST estimation with the highest accuracy was obtained at a 5-cm depth using BT-GPR at Giresun station (RMSE = 0.0439, R2 = 0.9535, MAE = 0.0344 in the testing phase) and Bayburt station (RMSE = 0.0525, R2 = 0.9438, MAE = 0.0412 in the testing phase). These outcomes provide helpful benchmarking guidance for future soil temperature investigation at various depths across the selected regions.
AtıfScopus12WoS14OpenAlex21İncele - Kitap BölümüYalnız künye2022Non-Family Managers and HR Practices of Family Firms
Yazici, Ömer
Family firms have one special factor that makes them unique and competitive compared to non-family firms, and that is family involvement. Family firms are composed of management, family, and ownership. While this composition often has many advantages, it also has some downfalls. Family involvement has a significant impact on the behavior of the company, more specifically on the human resource (HR) management practices of the company. As a result, family firms have to deal with nepotism, self-dealing, and entrenched management issues to hire and retain professional non-family managers and other white-collar workers. Family firms are intended to be the career center for family employees (Bloemen-Bekx et al. 2019). Therefore, family firms have different HR compositions. There are mainly three types of employees in family firms; first, the shareholder family members and their heir (ownership), second, the other family members and relatives (family), and third, the non-family employees (management). Non-family employees are divided into two categories, managers and workers. Although family firms have a tendency to assign family members to crucial positions at the firm (Deloitte and Touche Study 1999), non-family employees are hired for other executive and managerial positions, which is more crucial for family firms (Chua et al. 2003). Considering all these challenges and difficulties due to family involvement in employee relations, researchers raise the question of whether “family firms are good employers” (Neckebrouck et al. 2018). Family firms diverge from non-family firms with their long-term orientation and caring approach to their employees. This caring approach is proven in downsizing studies. Researchers show that during crises and downsizing practices, family firms lay off fewer employees than non-family firms (Stavrou et al. 2007). Non-family employees are keystones of the family firm’s growth and necessary for each growing family firm. Therefore, the employment of non-family members will affect the sustainability of the firm. While it is important for all types of companies, it is crucial for family firms to have committed and devoted non-family employees. Hiring non-family managers is usually a result of a limited family employee presence during the growth of the company. Controlling growth due to a limited family member presence and running a firm with only family managers would result in informal structures, peculiar culture, and limited growth. Non-family managers are sometimes hired as conflict resolution when there is a conflict of interest during the employment of family members (Lubatkin et al. 2005). Hence mostly non-family managers are hired if there is a formalization process in progress (Zhang and Ma 2009). Also, most first non-family managers in the firm are CEOs. Furthermore, family firms with financial struggles tend to employ a non-family CEO rather than a family CEO (Bocatto et al. 2010). According to a study done with Italian firms, family firms prefer to nominate non-family CEOs rather than family CEOs (Salvato et al. 2012). Additionally, in growth times, family firms also prefer non-family CEOs over family CEOs. In conclusion, while family firms are able to fill managerial positions, it is empirically shown that the growth of family firms is correlated with non-family managers (Fang et al. 2015).
