Sürdürülebilir Kalkınma Amaçları
Yazarlar
- Dertli, Enes(116)
- Şahin, Engin(48)
- Kaya, Yunus(46)
- Özen, Soner(46)
- İspirli, Hümeyra(45)
- Pat, Suat(44)
- Şenay, Volkan(42)
- Korkmaz, Şadan(36)
- Yilmaz, Mustafa Tahsin(33)
- Kutlu, Naciye(32)
- Cuce, Erdem(31)
- Öner, Erdal(31)
- Artar, Musa(30)
- Ertugrul, Mehmet(29)
- Hasar, Ugur Cem(29)
- Mercan, Emin(28)
- Bayraktar, Bülent(27)
- Bayram, Sinan(27)
- Can, Zehra(25)
- Ecem Bayram, Nesrin(25)
- Çolak, Murat(23)
- Özdemir, Akın(23)
- Cuce, Pinar Mert(22)
- Sert, Durmuş(22)
- Ayata, Ümit(21)
- Bayram, Ozkan(21)
- Dirican, Ebubekir(20)
- Abdioglu, Murat(19)
- Ayazoglu, Rabil(19)
- Birinci, Ahmet(19)
- Kamiloğlu, Aybike(19)
- Gerçek, Yusuf Can(18)
- Taylan, Osman(18)
- Tozlu, Alperen(18)
- Gul, Volkan(15)
- Hasar, Ugur C.(15)
- Kadakal, Mahir(15)
- Sagdic, Osman(15)
- Ergün, Mustafa(14)
- Kadakal, Huriye(14)
Yayınlar
- MakaleAçık Erişim2019Scopus SJRQ1Electrospraying method for fabrication of essential oil loaded-chitosan nanoparticle delivery systems characterized by molecular, thermal, morphological and antifungal properties
Yilmaz, Mustafa Tahsin; Yilmaz, Azime; Akman, Perihan Kubra; Bozkurt, Fatih; Dertli, Enes; Basahel, Abdulrahman; Al-Sasi, Basil; Taylan, Osman; Sagdic, Osman
Fabrication of essential oil loaded-chitosan nanoparticles using electrospraying technique appears to be a novel strategy to develop thermally stable nanoparticles possessing higher encapsulation efficiency and particle stability. This study aims to fabricate chitosan nanoparticles (CNPs) loaded with Origanum vulgare essential oil (OEO, Origanum vulgare L.) at different proportions (OEO/CH proportions of 0:1, 0.0625:1, 0.125:1, 0.25:1 and 0.5:1 mL/g) using electrospraying technique. The CNPs were characterized in term of their particle size and stability (dynamic light scattering), encapsulation efficiency (spectrophotometry), and molecular (Fourier transform infrared spectroscopy), thermal (differential scanning calorimetry/thermogravimetric analysis), morphological (scanning electron microscopy) and antifungal (agar dilution method) and fungistatic activity properties. The average particle sizes of the CNPs ranged between 290 and 483 nm with a spherical morphology. Positively charged surface characteristics were observed to increase with the increment of OEO concentration in CNPs. The encapsulation efficiency values were determined in the range of 70.1 and 79.6%. The molecular and thermal analyses exposed very decent encapsulation of OEO into thermally stable chitosan nanoparticles. Morphological analysis verified the spherical shapes of these nanoparticles. Above all, the antifungal effectiveness of OEO against the Alternaria alternata AY1 could be significantly (p < 0.05) increased by its encapsulation into chitosan nanoparticles fabricated by the electrospraying technique. Consequently, it can be stated that the electrospraying technique developed is able to fabricate thermally stable nanoparticles owning higher encapsulation efficiency and particle stability. The results and findings suggest that the electrospraying technique would be a promising method to fabricate chitosan-based nanoparticles as an antimicrobial agent to control their release in a prolonged preservative effect in cosmetic, pharmaceutical and food applications for adjustable dosage forms. Industrial relevance: The fungal agents such as Alternaria alternata cause great damages on post-harvest fresh fruits and vegetables, thus leading to a great economical lose. Therefore, a great variety of methods in struggling with disease have been previously proposed. Nowadays, the most effective leading methods to struggle against plant diseases are those applied with synthetic fungicides to minimize such lose in post-harvest fruit and vegetables. However, intensive and unconscious use of the fungicides leads the pathogens to develop resistance against these agents as well as to accumulation of chemical residues in soil, water and air and finally to formation of carcinogenic effects on human health. Nowadays, a great effort is being exerted to develop novel biodegradable and natural antimicrobial agents for struggling fungal spoilage in postharvest products. Essential oils are among the most widely used natural struggling methods. Essential oils obtained from plants have been extensively used since they are natural antimicrobial agents. However, they cannot be effectively used in spite of their extensive applications. Recently, some researches in the field of nanotechnology have demonstrated that the effectiveness of active substances could be increased by using some techniques. In this respect, we aimed at developing essential-oil-loaded-chitosan-nanoparticle delivery systems using an electrospraying deposition system to prevent fungal colonization on food and plant materials. By increasing antifungal effectiveness of essential oils by their encapsulation into nanoparticles, it will be possible to decrease the levels of regularly applied dose and reflect the obtained outcomes to the food and agriculture industry. This study is the first example of production of essential oil loaded nanoparticles using the electrospraying-hydrodynamic process and showed that encapsulation of oregano essential oil into chitosan based nanoparticles (CNPs) by using the electrospraying deposition technique considerably increased the antifungal effectiveness of the Origanum vulgare essential oil. Our results highlight the potential use of the chitosan nanoparticles (CNPs) loaded with different amounts of Origanum vulgare in food and agriculture industry as an effective fungicidal material against Alternaria alternata, suggesting that the CNPs can be promising tools to compete with synthetic fungicide counterparts and limit use of synthetic ones for struggling of food and plant pathogens. Therefore, the results of this study should be of great importance to industrial applications in terms of development of natural, but effective preservatives as alternative to synthetic ones. In this respect, the CNPs would find a great industrial application area in the food and agriculture industry which seek natural preservatives due to the recent health concerns.
AtıfScopus119WoS101OpenAlex118
İncele - MakaleAçık Erişim2019Scopus SJRQ3A functional bleeding test apparatus for concrete
Gökçe, H. Süleyman; Andiç-Çakır, Özge
Bleeding is one important indicator that is related to the physical and mechanical properties of fresh and hardened concrete. Standards generally prefer methodologies that are similar to one another to measure the bleeding of fresh concrete. The preferred test apparatus used in the standards is troublesome because it requires a manual test procedure and repeated measurements until final setting of the fresh concrete. The functional bleeding test apparatus presented in this study will ease test performance and eliminate the faults caused by the test procedure and the experimenter.
AtıfScopus2WoS1OpenAlex3İncele - MakaleAçık Erişim2019Scopus SJRQ1Characterization of chemical, molecular, thermal and rheological properties of medlar pectin extracted at optimum conditions as determined by Box-Behnken and ANFIS models
Al-Amoudi, Rami H.; Taylan, Osman; Kutlu, Gozde; Can, Asli Muslu; Sagdic, Osman; Dertli, Enes; Yilmaz, Mustafa Tahsin
In this work, response surface methodology and adaptive neuro-fuzzy inference system approaches were used to predict and model effect of extraction conditions of pectin from medlar fruit (Mespilus germanica L.). The pectin extracted at optimized conditions (89 °C, 4.83 h and 4.2 pH) could be classified as high methoxyl pectin. Sugar composition analysis showed that pectin was mainly composed of D-galacturonic acid, L-arabinose, L-rhamnose, D-galactose and D-glucose. Fourier Transform Infrared Spectroscopy, RAMAN and nuclear magnetic resonance spectra confirmed molecular structure, revealing presence of D-galacturonic acid backbone. X-ray diffraction patterns revealed an amorphous structure. Differential scanning calorimetry showed endothermic (123 °C) and exothermic peaks (192 °C). Thermogravimetric analysis revealed three decomposition regions, 50–225 °C, 225–400 °C and 400–600 °C. Steady and dynamic shear analyses revealed that pectin had a pseudo-plastic behavior with storage (G′) and loss (G″) modulus increasing with increment in frequency, indicating viscoelastic structure more predominantly elastic than viscous.
AtıfScopus89WoS79OpenAlex83
İncele - MakaleAçık Erişim2019Scopus SJRQ2A study of gamma attenuation property of UHMWPE/Bi 2 O 3 nanocomposites
Abdalsalam, Alyaa H.; Sayyed, M.I.; Ali Hussein, Thulfiqar; Şakar, Erdem; Mhareb, M.H.A.; Ceviz Şakar, Betul; Alim, Bünyamin; Kaky, Kawa M.
In this study, nanocomposite material made of ultra-high molecular weight and bismuth oxide was developed to be used for protection from nuclear radiation. The traditional hot-pressing technique was used for preparing composite samples. The concentrations of Bi 2 O 3 were selected to be 0.5, 1.0, 1.5, 2.0 wt%. In order to study the changes in surface morphology, we examined all samples by scanning electron microscopic (SEM). We evaluated the semi-quantitative of all elements used to fabricate these samples using EDX. Additionally, all samples including pure Bi 2 O 3 has been examined with X-ray diffraction (XRD). Besides that, Raman spectroscopy of all synthesized polymer matrix was measured to explore the different molecular groups. Also, the photon attenuation ability for the present samples was measured experimentally at eight energies varying from 30.8 keV to 383.9 keV using 133 Ba radioactive point source.
AtıfScopus68WoS64OpenAlex70İncele - MakaleYalnız künye2019Scopus SJRQ2Investigation on seismic isolation retrofit of a historical masonry structure
Artar, Musa; Çoban, Keziban; Yurdakul, Muhammet; Can, Ömer; Yilmaz, Fatih; Yildiz, Mehmet B.
In this study, seismic vulnerability assessment and seismic isolation retrofit of Bayburt Yakutiye Mosque is investigated. Bayburt Yakutiye Mosque was built in the early 19th century at about 30-meter distance to Coruh river in the center of Bayburt in Turkey. The walls of historical masonry structure were built with regional white and yellow stones and the domes of the mosque was built with masonry bricks. This study is completed in four basic phases. In first phase, experimental determination of the regional white stone used in the historical structure are investigated to determine mechanical properties as modulus of elasticity, poison ratio and compression strengths etc. The required information of the other materials such as masonry brick and the regional yellow stone are obtained from literature studies. In the second phase, three dimensional finite element model (FEM) of the historical masonry structure is prepared with 4738 shell elements and 24789 solid elements in SAP2000 software. In third phase, the vulnerability assessment of the historical mosque is researched under seismic loading such as Erzincan (13 March 1992), Kocaeli (17 August 1999) and Van (23 November 2011) earthquakes. In this phase, the locations where damage can occur are determined. In the final phase, rubber base isolators for seismic isolation retrofit is used in the macro model of historical masonry mosque to prevent the damage risk. The results of all analyses are comparatively evaluated in details and presented in tables and graphs. The results show that the application of rubber base isolators can prevent to occur the destructive effect of earthquakes.
AtıfScopus12WoS12OpenAlex6İncele - MakaleAçık Erişim2019Scopus SJRQ3Biodiversity and characterization of gram-positive, catalase-positive cocci isolated from pastırma produced under different curing processes
Fettahoğlu, Kübra; Çinar, Kübra; Kaya, Mükerrem; Kaban, Güzin
The aim of this study was to determine the effects of different curing temperatures (4 °C or 10 °C) and agents (KNO3 or NaNO2) on microbiological and physicochemical properties of pastırma and diversity of gram-positive, catalase-positive cocci (GCC+) and also to investigate some technological properties of the strains. Four different groups of pastırma were produced applying different curing temperatures and agents. After production, GCC+ isolated from pastırma were subjected to phenotypic and genotypic (16S rRNA sequencing) identification. Genotypically characterized strains were evaluated for their technological properties. In all groups, aw and pH were observed to be under 0.90 and over 5.5, respectively. In genotypic identification, 45 isolates were identified as Staphylococcus vitulinus, while other isolates identified were S. equorum (n = 15), S. saprophyticus (n = 15), and S. xylosus (n = 12). All of the strains could grow at different salt concentrations (8% and 15%) and temperatures (4 °C, 10 °C, and 37 °C). Four strains of S. saprophyticus showed strong lipolytic activity while nine strains of S. vitulinus had strong proteolytic activity. This study showed that different curing temperatures and agents are particularly effective on the microflora in pastırma; however, these factors do not cause a high diversity in GCC+ in terms of species.
AtıfScopus6WoS6OpenAlex7TR Dizin2
İncele - MakaleAçık Erişim2019Scopus SJRQ3A signal timing assignment proposal for urban multi lane signalised roundabouts
Murat, Yetis Sazi; Cakici, Ziya; Tian, Zong
The relationship between the left-turning traffic volume and the storage area at signalised roundabouts is investigated, and a calculation procedure for signal timing is proposed in this paper. The parameters associated with the developing stages of a new expression/ model are also defined. Four different signal timing scenarios are considered. The results show that the proposed formula can be used for the design of signalised roundabouts.
AtıfScopus11WoS7OpenAlex9İncele - MakaleYalnız künye2019Scopus SJRQ1Vertically oriented graphene nano-sheets grown by plasma enhanced chemical vapor deposition technique at low temperature
Bayram, Ozkan; Simsek, Onder
In this study, it was aimed to obtain vertically-oriented graphene nano-sheets (VGNs) on copper foils using CH 4 gas as the precursor material by means of plasma enhanced chemical vapor deposition (PECVD) technique. VGNs were obtained at 50 W, 75 W and 100 W Radio Frequency (RF) powers by this technique and the effect of RF power on the morphological structure of graphene layers was investigated. VGNs were also analyzed by Raman spectroscopy, scanning electron microscopy (SEM) and water contact angle (WCA) measurements. The SEM images showed that the VGNs became more tightly packed with the increase of RF power and thus these coating parameters had a significant effect on the morphological structure. WCA analyzes for VGNs were also performed and it was found that VGNs obtained at 100 W RF power had higher contact angle value than the other RF powers. These VGNs, which have both large surface area and optically transparent, are thought to be materials that have the potential to be used in supercapacitors and solar cells.
AtıfScopus19WoS17OpenAlex19İncele - MakaleYalnız künye2019Scopus SJRQ3Response surface methodology as optimization strategy for asymmetric bioreduction of acetophenone using whole cell of Lactobacillus senmaizukei
Çolak, Nida Sezin; Şahin, Engin; Dertli, Enes; Yilmaz, Mustafa Tahsin; Taylan, Osman
Whole cell applications are one of the main methodologies for the bioreduction of prochiral ketones to obtain enantiomerically rich chiral secondary alcohols which are mainly affected by the culture parameters of the whole cell. In this study, whole cell of Lactobacillus senmaizukei as a safe Lactic Acid Bacteria (LAB) was used for the reduction of acetophenone and Response Surface Methodology (RSM) application was used to optimize the culture parameters in terms of temperature, pH, incubation time, and agitation level to obtain the highest enantiomeric excess (ee) and conversion rate. The predicted optimum conditions for the bioreduction with whole cell Lactobacillus senmaizukei were found to be pH of 5.25, temperature of 25 °C, incubation time of 72 hr, and agitation level of 100 rpm. Importantly, the efficiency of the reduction of the acetophenone was significantly affected by the linear and quadratic effects of culture parameters. These findings are important to show the role of culture parameters for the bioreduction reactions and also the efficiency of the RSM technique to optimize these parameters.
AtıfScopus10WoS10OpenAlex11İncele - MakaleAçık Erişim2019Scopus SJRQ2Employment of emergency advanced nurses of Turkey: A discrete-event simulation application
Atalan, Abdulkadir; Donmez, Cem Cagri
In the present study, problems in emergency services (ESs) were dealt with by analyzing the working system of ESs in Turkey. The purpose of this study was to reduce the waiting times spent in hospitals by employing advanced nurses (ANs) to treat patients who are not urgent, or who may be treated as outpatients in ESs. By applying discrete-event simulation on a 1/24 (daily) and 7/24 (weekly) basis, and by employing ANs, it was determined that the number of patients that were treated increased by 26.71% on a 1/24 basis, and by 15.13% on a 7/24 basis. The waiting time that was spent from the admission to the ES until the treatment time decreased by 38.67% on a 1/24 basis and 53.66% on a 24/7 basis. Similarly, the length of stay was reduced from 82.46 min to 53.97 min in the ES. Among the findings, it was observed that the efficiency rate of the resources was balanced by the employment of ANs, although it was not possible to obtain sufficient efficiency from the resources used in the ESs prior to the present study.
AtıfScopus9WoS8OpenAlex13İncele - MakaleAçık Erişim2019Scopus SJRQ3Yogurt ice cream sweetened with sucrose, stevia and honey: Some quality and thermal properties
Arslaner, Ayla; Salik, Mehmet Ali; Özdemir, Salih; Akköse, Ahmet
This study investigated the effects of some sweeteners (sucrose, honey and stevia) on the quality and thermal properties of plain (P) and cocoa (C) yogurt ice cream. For this purpose, six different yogurt ice cream samples were prepared with sucrose (control: AP, AC), with honey (BP, BC) and with stevia (CP, CC). The highest values of protein, ash, fat, lactose ratios and lightness (L∗) were measured in samples with stevia. The addition of honey increased the b∗values. The addition of cocoa increased pH and viscosity, but decreased overrun ratios. Although the addition of stevia reduced the lactic acid bacteria (LAB) counts, in all samples the LAB count was above 6 log CFU/g during storage. Results of the thermal and melting analysis showed that the use of stevia had a positive effect on the ice cream stability by increasing the freezing and melting point peak temperatures (Tf, Tm), the enthalpy (ΔHf, ΔHm), and the initial ice crystal melting temperatures (T'm).
AtıfScopus18WoS14OpenAlex16İncele - MakaleYalnız künye2019Scopus SJRQ3Effects of autochthonous Lactobacillus plantarum strains on Listeria monocytogenes in sucuk during ripening
Kamiloğlu, Aybike; Kaban, Güzin; Kaya, Mükerrem
The aim of this study was to investigate the effects of autochthonous Lactobacillus plantarum strains (S50, S51, S72, S74, and S85) as starter cultures on growth of Listeria monocytogenes in sucuk (Turkish dry fermented sausage) production. The counts of L. monocytogenes, lactic acid bacteria, and Enterobacteriaceae as well as pH value and moisture content were determined in sucuk during ripening period. L. monocytogenes, lactic acid bacteria, and pH value were significantly affected (p < 0.01) by both starter culture and ripening period. A slight increase in L. monocytogenes count was observed in the control group whereas a reduction was observed in samples produced with L. plantarum strains at the first day of fermentation. Although L. monocytogenes reduction in control group with spontaneous microbiota was 0.54 log cfu/g after 11 days of ripening, reductions of as high as 2.74 log cfu/g was observed in the presence of L. plantarum S50. Practical applications: In the current study, five different autochthonous Lactobacillus plantarum isolates were identified, the effects of these strains on the behavior of Listeria monocytogenes in Turkish fermented sausage (sucuk) were determined. To the best of our knowledge, this is the first report investigating the effects of autochthonous lactic acid bacteria strains on behavior of L. monocytogenes in sucuk fermentation. As starter culture autochthonous lactic acid bacteria can be more competitive than commercial types. Our findings reveal the importance of the use of these autochthonous L. plantarum strains causes rapid pH drop to inhibit L. monocytogenes growth during sucuk fermentation. And also L. plantarum S50 strain may be more suitable for use as bioprotective culture or starter culture compared to other strains.
AtıfScopus27WoS24İncele - MakaleAçık Erişim2019Scopus SJRQ2Uniform boundedness of kantorovich operators in variable exponent Lebesgue spaces
Ayazoglu, Rabil; Akbulut, Sezgin; Akkoyunlu, Ebubekir
In this paper, the Kantorovich operators Kn, n ϵ N are shown to be uniformly bounded in variable exponent Lebesgue spaces on the closed interval [0, 1]. Also an upper estimate is obtained for the difference Kn (f) − f for functions f of regularity of order 1 and 2 measured in variable exponent Lebesgue spaces, which is of interest on its own and can be applied to other problems related to the Kantorovich operators.
AtıfScopus3WoS3OpenAlex3İncele - MakaleAçık Erişim2019Scopus SJRQ3Plasma polymerized linalool (ppLin): An antimicrobial and biocompatible coating
Çakmak, Kenan; Bayram, Özkan; Solak, Kübra; Kaban, Güzin; Şimşek, Önder; Mavi, Ahmet
Bacterial infections in medical devices and drug resistance of bacteria can cause chaos in the world due to loss of lives in addition to the cost of device revisions, quarantine, disinfection of infected areas, and patient treatment. Antibacterial coatings of essential oils on medical devices can prevent bacterial attachment and reduce costs. Linalool is an antibacterial constituent of essential oils. Herein, we examine for the first time the fabrication and characterization of radio frequency (RF) plasma polymerized hydrophilic thin films from linalool (ppLin) by varying deposition parameters (RF power and deposition time) and the behavior of ppLin with two bacteria (Escherichia coli and Staphylococcus aureus) commonly related to microbial contamination of medical devices. While a dramatic reduction in E. coli and S. aureus attachment was observed on ppLin films, their hydrophilic surface was also bactericidal to S. aureus. Additionally, ppLin films were shown to be adherent and noncytotoxic to human fibroblast cells. ppLin can be potentially integrated into medical and other clinical devices as a promising low-cost biocompatible antimicrobial coating.
AtıfScopus8WoS8İncele - MakaleAçık Erişim2019Scopus SJRQ2The role of cobalt doping on the optical and structural properties of Mn 3 O 4 nanostructured thin films obtained by SILAR technique
Bayram, Ozkan; İgman, Erdal; Guney, Harun; Simsek, Onder
Cobalt doped manganese oxide thin films (Mn 3 O 4 :Co) were successfully deposited on soda lime glass substrates using SILAR technique. Mn 3 O 4 :Co thin films were characterized using XRD, SEM, Uv–VIS and Raman spectroscopy. The XRD spectra showed that thin films had substantially Hausmannite crystal structure. The preferential orientation of the pure and 0.5 at.% Co doped manganese oxide thin films (Mn 3 O 4 ) was (002), but with increasing Co doping, it was detected that this preferential orientation shift towards the (211) plane. The absorbance, transmittance and optical band gap of the Mn 3 O 4 :Co thin films were determined using Uv–Vis spectroscopy and these properties of the thin films differed considerably due to cobalt doping. The optical band gap of pure Mn 3 O 4 thin films was 2.00 eV, but on the other hand, due to the Co doping this value increased before and then decreased slightly. Optical transmittance of Mn 3 O 4 :Co films increased from 60% to 72% with the effect of Co doping. A1g mode, which is the characteristic vibration peak of Mn 3 O 4 films, was confirmed for pure and doped Mn 3 O 4 thin films at a wavelength of 658 nm.
AtıfScopus26WoS24OpenAlex25İncele - MakaleAçık Erişim2019Scopus SJRQ3An explicit characterization of spherical curves according to Bishop frame and an approximately solution
Balki Okullu, Pinar; Kocayigit, Huseyin; Agirman Aydin, Tuba
In this paper, spherical curves are studied by using Bishop frame. First, the differential equation characterizing the spherical curves is given. Then, we exhibit that the position vector of a curve which is lying on a sphere satisfies a third-order linear differential equation. Then we solve this linear differential equation by using Bernstein series solution method.
AtıfScopus2OpenAlex1İncele - MakaleAçık Erişim2019Scopus SJRQ3Modeling of the impact of initial mold temperature, Al5Ti1B and Al10Sr additions on the critical fraction of solid in die casting of aluminum alloys using fuzzy expert system
Teke, Ç.; Çolak, M.; Taş, M.; İpek, M.
In the casting of liquid metal, the feeding stops when the mushy zone is clogged and does not allow the transfer of feeding liquid. The growing resistance of the solid dendrites against the fluidity of the feeding liquid is defined as the critical fraction of solid (CFS). CFS value varies depending on many factors such as alloy solidification range, initial mold temperature, and the grain size. Therefore, in many casting simulation applications, it is quite common to get inconsistent results due to insufficient information about the CFS. In this study, a fuzzy expert system (FES) model has been developed in order to determine the value of the CFS in the die casting process, based on the parameters of the alloy type, the initial mold temperature, Al5Ti1B addition and Al10Sr addition. In order to create the rule base for the FES model, 54 die casting experiments have been carried out. The CFS values obtained using the FES model has revealed that the developed model of the FES predicts the CFS value in a high performance.
AtıfScopus4WoS3OpenAlex6İncele - MakaleAçık Erişim2019Scopus SJRQ2Comparison of colony performances of honeybee (Apis Mellifera L.) housed in hives made of different materials
Erdoğan, Yaşar
Numerous flowering plants rely on bees for pollination. Any natural or anthropogenic factor that threatens colony survival can have a large impact on plant production. This study investigates the effects of manmade hives built from different materials and how these may influence colony growth. Ten each of three hive types were selected, wooden, polystyrene and composite insulated hives. Factors of adult bee numbers, brood development, nectar flow period weight gain, bee flight activity, aggression response, and honey yield were selected markers of hive development. Statistically, each hive type produced significant variation (p<.05). The greatest overall productivity across all factors was for insulated hives made of composite material, with honey production approximately 35% times that of wood, 14% times that of polystyrene and in terms of the development of honeybee colonies, the average of other hives is 10.2 times.Highlights Relative humidity and temperature are important environmental factors for honeybees. Insulated hives, increased honey yield. High temperature and humidity inside the hive made honeybees more aggressive.
AtıfScopus12WoS6OpenAlex14İncele - MakaleYalnız künye2019Scopus SJRQ2Leaded brass alloys for gamma-ray shielding applications
Şakar, Erdem; Büyükyıldız, Mehmet; Alım, Bünyamin; Şakar, Betül Ceviz; Kurudirek, Murat
The leaded brasses show high machinability and atmospheric corrosion resistance. Hence, they are being used in different applications such as machine parts, valves, fittings etc. Besides, they can serve as radiation shields as they contain lead and their radiation shielding properties were not investigated so far. Thus, the aim of this study is to determine the radiation shielding properties of leaded brasses. Standard (CuZn) and leaded (CuZnPb) brasses were prepared and their mass attenuation coefficients (μ/ρ), half-value layers (HVL), tenth-value layers (TVL), mean free paths (MFP) and effective atomic numbers (Z eff ) were determined. Linear attenuation coefficients (μ) of the alloys were measured first at 53, 276, 302, 356 and 383 keV using a HPGe detector and a 133 Ba radioactive source. These values were then used to obtain other parameters. A good agreement was observed between experimental and theoretical results for HVL, TVL and MFP (Dif. ≤ 9%). Photon buildup through the present materials was studied in terms of exposure buildup factor (EBF). Results were presented and discussed regarding the photon energy and penetration depths. Fast neutron removal cross sections were also calculated for the given alloys. Some alloys were also evaluated morphologically by using EDX mapping. The leaded brasses were compared with standard shielding concretes and superior shielding properties against gammas and fast neutrons were obtained when compared with concretes.
AtıfScopus114WoS108OpenAlex128İncele - MakaleYalnız künye2019Scopus SJRQ4Evaluating the grinding process of granitic rocks using the physico-mechanical and mineralogical properties
Kahraman, Sair; Ucurum, Metin; Yogurtcuoglu, Emine; Fener, Mustafa
Granitic rocks are sometimes ground for different purposes. Predicting the mean particle size (d50) is useful for planning and cost estimation of purposes. In order to investigate the possibility of predicting the d50 of ground rock from the physico-mechanical rock properties, six different granites were tested in the laboratory. First, the d50 values were correlated with the corresponding physico-mechanical properties. The simple regression analysis showed that there were no good correlations between the d50 and the physico-mechanical properties. Then, the multiple regression analysis was carried out and strong prediction equations were developed. It was also shown that the dominant parameter in grinding was the abrasive mineral content of rock. It is concluded that the d50 of granites can be predicted from the derived multiple regression equations especially for preliminary investigations. The developed estimation equations including index test values are especially useful since they are easy to use.
AtıfScopus2WoS1İncele