Makine ve Metal Teknolojileri Bölümü Makale Koleksiyonu

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Prediction of drying kinetics and energy consumption values of purple carrots dried in a temperature-controlled microwave dryer by decision tree, random forest and ada boost approaches
(Elsevier B.V., 2025) Malaslı, Mehmet Zahid; Akkoyunlu, Mehmet Cabir; Pekel, Engin; Taşova, Muhammed
In the literature have focused on modeling data obtained under drying conditions with different methods and comparing them with each other. However, any studies have been found on estimating the behavior of the same material under different drying conditions. Therefore, a study was conducted to predict the behavior of the same material under different drying conditions. In the study, primarily purple carrot slices were reduced from 6.13 ± 0.05 to 0.14 ± 0.018 g moisture/g dry matter value. Among the models, the drying rates were best estimated by the Midilli-Küçük (R2: 0.9993) model. The lowest energy consumption was determined as 0.285 kWh in the drying process at 70 °C. Estimation of intermediate values is very useful because experimental studies can be length and expensive. Sometimes, even if cost is not a concern, long-term experimental studies and the high number of experiment repetitions increase the importance of estimation methods for researchers. The decision tree, random forest and ada boost methods, which are fast operating methods, were used as estimation methods in this study. MAPE and R2 success values are expressed for all three methods. The Decision Tree method was found to be the most successful technique with the highest R2 value (0.96) and the lowest MAPE value (0.03). © 2025 Elsevier B.V.
Poly(ethylene glycol) patterned surfaces functionalized with gallic acid@Au nanoparticles: investigation of antibacterial activity for biomedical applications
(Springer, 2024) Karaağaç, Zehra
Polymer patterns are promising for many applications due to their high stability and superior chemical and physical properties. By functionalizing various surfaces with polymer patterns, it is possible to detect and prevent many common infections. Treatment of resistant bacteria with antibiotics is limited and they can spread quickly. For this reason, it was designed a surface that can prevent contamination by functionalizing polymer patterns. In the study, a polymer pattern model obtained by combining gallic acid with gold nanoparticles (GA@AuNP) synthesized through green chemistry was designed. Polymer-patterned structures were obtained on silicon wafers using Poly(ethylene glycol) (PEG) polymer and were self-assembled with GA@AuNPs. Diagnosis and inhibition of bacterial cells in a short time were demonstrated with the prepared modified PEG polymer pattern. Surface-enhanced Raman scattering effects were used to optimize the stability of surfaces patterned with self-assembled GA@Au NPs. By modification of PEG polymer patterns, a biomarker design that can be used in many different bioapplications is proposed.
Examination of industry 4.0 awareness, perceptions, and actions of employees in furniture and board businesses
(Forest Products Society, 2024) Kırklıkçı, Ahmet Bora
Industry 4.0 (I 4.0) is a major transformation in manufacturing that is driven by the use of digital technologies. Furniture and board businesses are one of the subsectors of the forest products sector that can benefit from I 4.0. In this study, a survey was administered to 206 employees working in furniture and board businesses to understand their awareness of I 4.0, their perceptions regarding its obstacles and potential benefits and practices. The most widely recognized I 4.0 technology by employees is digital connectivity. Employees also see the potential for I 4.0 to help them implement new business models. However, the main obstacles to implementing I 4.0 are a lack of skilled workers and high costs. Employees of furniture businesses are less aware of I 4.0 than are employees of board businesses. Additionally, only a small percentage of businesses in both sectors have an I 4.0 or smart manufacturing strategy. The results of this study suggest that furniture and board businesses need to do more to raise awareness of I 4.0 and to develop strategies for implementing it. By doing so, they can improve their productivity and competitiveness in the global marketplace. This study was conducted on a relatively small sample in a limited area, so the generalizability of the results is low. © 2024
Perceptions of forest product businesses employees in Turkey regarding occupational health and safety during the COVID-19 pandemic
(IOS Press BV, 2024) Kırklıkçı, Ahmet Bora; Bayram, Serap
BACKGROUND: The COVID-19 pandemic has undeniably brought up the issue of Occupational Health and Safety (OHS) for businesses in Turkey. In this global pandemic, strategies developed to effectively address OHS risks and eliminate them with reliable, high-quality data have gained importance. OBJECTIVE: This study aimed to determine the perceptions of employees in the forest products industry in Turkey regarding the OHS during the COVID-19 pandemic. METHOD: The sample of the descriptive and analytical study consisted of a total of 371 employees in forest product businesses located in Turkey. The sample of the study was determined by the purpose-based sampling method. Data were collected both online and face-To-face from June 2022 to October 2022. The data were obtained using the Questionnaire of Employee and Business Characteristics and the Scale of Employees' Perceptions on the OHS (S-POHS) adapted by Özden (2022). Statistical analysis was performed using SPSS and calculated by descriptive analyses, pairwise comparison tests and multivariate regression analyses. RESULTS: 39.1% of the employees with a mean age of 34.12±8.78 years are high school graduates and 61.5% are workers. Significant differences were found in the S-POHS average scores of the employees in the businesses that produce paper-cardboard, have operated for less than 20 years, have a partnership structure with foreign capital and have an OHS Management System Quality Certificate (p < 0.05). CONCLUSION: While a positive OHS perception level has already been achieved in the forest products industry in business administrations and by employees, it is clear that this should not be lost and it should be prepared for the next crises by adding new applications.
An investigation of the perception of institutionalization in the furniture and board manufacturing businesses from the perspective of managers before and during the Covid-19 pandemics
(ADAMOR Toplum Araştırmaları Merkezi, 2022) Kırklıkçı, Ahmet Bora
The COVID-19 pandemic has affected businesses and business models in different ways across all industries. The forest products industry plays an important role in sustainable development not only with its unique raw material, but also because of the continuing globalization of the industry. This study was carried out in order to compare the institutionalization perceptions of the managers of 106 businesses in the furniture and board manufacturing sectors, most of which are medium-sized and family/personal ownership, before and during the COVID-19 pandemic. While the level of institutionalization perception before and during the COVID-19 pandemic is very close to the medium level in all sub-dimensions and in total, the change in the last four years is significantly lower in all sub-dimensions during the pandemic. This result showed that the COVID-19 pandemic seriously affected the institutionalization processes of the furniture and board manufacturing businesses in terms of consistency, formalization, transparency and accountability. The results of this study revealed that the institutionalization of the furniture and board manufacturing sectors show serious changes according to the changing conditions and it is important for managers to take measures to adapt to these changes, taking into account different crisis scenarios that will result in expansion and recession.
Kurumsallaşma sürecindeki orman ürünleri sanayi işletmelerinin COVID-19 pandemisinde kriz yönetim planlamaları
(Isparta Uygulamalı Bilimler Üniversitesi Orman Fakültesi, 2022) Kırklıkçı, Ahmet Bora; Gedik, Tarık
Ekonomik alandaki etkisi özellikle 2020 yılının üçüncü çeyreğinden sonra çok daha fazla hissedilmeye başlanan COVID-19 pandemisinin her sektörde olumsuz bir yönü ortaya çıkmıştır. Kurumsallaşmış işletmeler diğer işletmelere göre pandemiden daha az etkilenmişlerdir. Yapılan bu çalışma ile belli bir düzeyde kurumsallaşmış ya da kurumsallaşma yolunda olan orman ürünleri sanayi işletmelerinin COVID-19 sürecindeki kriz yönetim planlamaları analiz edilmeye çalışılmıştır. İşletme yöneticileri ile bireysel derinlemesine görüşme yöntemi kullanılarak elde edilen veriler birleştirilmiş kalitatif araştırma raporlama kriterlerine uygun olarak kodlanmış, betimlenmiş, analiz edilerek yorumlamıştır. On dört farklı orman ürünleri sanayi işletmesinden elde edilen sonuçlara göre yöneticiler kriz için hazırlıklı olunması gerektiğini tanımlamışlar ve bu hazırlık durumunu da üst yönetimin yapması gerektiğini belirtmişlerdir. Yöneticilere göre pandemi süreci tüketici davranışlarında büyük değişikliklere neden olmuştur. Yöneticiler bu dönemin en çok işgücü kaybına ve iş ve pazar kaybına (ekonomik kayıp) neden olduğunu belirtmişlerdir. İşletme yöneticilerine COVID-19 pandemisinin etkilerini en aza indirmek için risk değerlendirmeleri yapmaları, acil durum planları hazırlamaları ve kriz yönetim modelleri geliştirmeleri önerilmektedir.
Determination of wear resistance of nickel-carbide alloy coating by atmospheric plasma spray technique on 30MnB5 alloy steel used in cultivator blades
(Institute of Physics, 2023) Dilay, Yusuf
The wear that occurs during tillage in agricultural machinery shortens the material’s life and increases costs. This study investigated the microstructure and morphology of cultivator blades coated with atmospheric plasma spray (APS) process and tested under real field conditions using OM, SEM, EDX, and XRD techniques. Abrasion tests were conducted in an area of 110 hectares and under two different soil moisture conditions. Material properties were investigated using hardness and surface roughness tests. The coating process was successful both mechanically and metallurgically by applying Ni-WC ceramic-metal (cermet) powder on the surface of 30MnB5 steel substrate with APS. The oxide and carbide structures detected on the coating surface by XRD studies resulted in a 1.5 times higher coating hardness. Due to the hard carbide phases in the coating matrix, the grooves on the wear surfaces were shallow and narrow compared to the substrate sample. The surface roughness values of the coated sample were approximately two times higher than the substrate sample. Due to the microstructure and high hardness, the coated specimen experienced three times less abrasion in both humidity conditions. The APS method can be successfully applied to the machined parts of tillage machines. In the near future, the cost of agricultural production can be reduced, and the environment can benefit from this method. In conclusion, this study presents a feasible approach to improving the wear resistance of Ni-WC ceramic-metal alloy by plasma spray coating under real field conditions.
The impact of workplace spirituality on perceived institutionalization and perceived performance
(Karamanoğlu Mehmetbey Üniversitesi, 2022) Kırklıkçı, Ahmet Bora
This study was planned to analyze the impacts of workplace spirituality on perceived institutionalization and perceived performance. Based on data from 190 employees in the industrial zone of a metropolitan city in Türkiye in 2021, simple linear regression analysis was utilized to determine the relationships and effects in the model. Engaging work sub-dimension proved 27% effective on perceived institutionalization (R=0.518; p<0.001) and 22% effective on perceived performance (R=0.471; p<0.001). The relationships are moderately and high level significantly. Businesses are able to reinforce their institutionalization efforts by supporting workplace spirituality. Especially, engaging work is positively influenced by approaches that are fair, consistent and that value employees.
Determination of abrasion resistance of Fe28Cr5C1Mn coating applied to 30MnB5 boron alloy cultivator blades via electric arc spray
(SAGE Publications Ltd., 2022) Güney, Bekir; Dilay, Yusuf
The poor abrasive wear behavior of agricultural machinery affects the farmers all over the world, rendering their activities more inefficient and negatively affecting their productivity. Therefore, innovation in the manufacture of soil cultivation machinery and the selection of wear-resistant materials has been of great importance. Recently, boron alloys, in particular, have been used in the manufacture of machinery parts that work the soil. The aim of this was to investigate the behavior of the blades of the machines widely used in soil cultivation in agricultural production following a surface treatment technique. For this purpose, the blades made of 30MnB5, a material widely used in the production of cultivator blades, were used as substrate samples in the trials as well as blades of the same substrate coated with Fe28Cr5C1Mn alloy wire via the electric arc spray technique. The morphologies and structures of the uncoated and coated samples were comprehensively analyzed by light microscopy, scanning electron microscopy, energy dispersive spectrometry and X-ray diffraction. In addition, their microhardness, porosity, and surface roughness properties were assessed separately before and after plowing. These prepared blades were tested under in the same conditions by plowing the same field at two different soil moisture. Although the weight loss was measured as 9.4 g and 5.4 g in the uncoated and in the coated sample at 9% moisture level, respectively, the weight losses were at 14% humidity level were 10.6 g and 5.9 g in the uncoated and coated samples, respectively. Although the amount of wear increased with increasing humidity levels in both groups, the mass wear loss in cultivator blades coated with Fe25Cr5C1Mn alloy wire was found to be lower in all trials. The results suggest that coating the cultivator blades using electric arc spray would increase agricultural productivity and reduce factors that cause environmental pollution.
Effect of cutting parameters on surface roughness and cutting forces in hard turning of 1.2367 hot work tool steel
(Gazi Üniversitesi, 2022) Erdem, Sümeyye; Özdemir, Mustafa; Rafighi, Mohammad; Yavuz, Mehtap
In this study, the effects of different cutting parameters on surface roughness (Ra) and cutting force were investigated in dry hard turning of 1.2367 hardened (55 HRC) hot tool steel. In this experimental study, the Taguchi method was used for the design of experiments, and a constant cutting depth; three different cutting speeds, and three different feed rates were selected as cutting parameters. The effects of cutting parameters on surface roughness and cutting forces were evaluated by performing an analysis of variance (ANOVA). According to the results, it was observed that the surface roughness value increased depending on the increase in the feed rate. On the other hand, the influence of cutting speed on the surface roughness was negligible. It was seen that the most effective parameter on the radial force (Fy), tangential force (Fy), and feed force (Fz) was the feed rate.
Wear properties and microstructure of WC-10Co-4Cr powder coating applied to cultivator blades via hvof
(World Scientific, 2022) Dilay, Yusuf; Güney, Bekir; Özkan, Adem
Abrasion of cultivator equipment parts working in the soil causes serious losses if necessary precautions are not taken. The cultivator blades used to plow the soil in agricultural production wear out over time. In order to reduce this wear, the hardness and wear resistance of the material should be increased first. In this study, some of the 30MnB5 cultivator blades were heat-treated and some were coated with HVOF technique. The samples were obtained by plowing the soil at 15-cm working depth and 5.4-kmh-1 forward speed in two fields with different soil moisture contents. As a result of the experiments, abrasion losses and surface deformation of the blade material were observed and the effect of soil moisture on wear was also determined. After the treatment of 49.5daa (decare) with soil at 9% moisture content, the heat-treated 30MnB5 sample was worn 5.6 g, and the sample coated with WC-10Co-4Cr was worn 3.2g. Abrasions at 14% soil moisture were 6.3 g and 3.6g, respectively. It was observed that the coated material was less corroded than the heat-treated material. While the results obtained will contribute to the prevention of economic losses, the release of metals into the soil will also be prevented.
Identification of durum wheat grains by using hybrid convolution neural network and deep features
(Springer Science and Business Media Deutschland GmbH, 2022) Çelik, Yüksel; Başaran, Erdal; Dilay, Yusuf
Convolution neural network (CNN) is a deep learning technique widely used in object identification and classification. One of the objects that are identified and classified is grain products. We proposed a hybrid CNN model to identify the dataset obtained from 41 different durum wheat grains in the present study. A new deep feature set was created in the proposed model by combining Logits and Pool10 feature layers of the CNN models MobileNetV2 and SqueezeNet. This new feature set has been classified into the support vector machines (SVM) input. As a result of the experimental tests performed with the proposed hybrid model on the durum wheat data set, an accuracy rate of 91.89% was obtained. In addition, within the scope of this study, a unique durum wheat data set was publicly presented to researchers and added to the literature.
Corrosion characteristics of plasma spray, arc spray, high velocity oxygen fuel, and diamond jet coated 30MnB5 boron alloyed steel in 3.5 wt.% NaCl solution
(De Gruyter Open Ltd., 2021) Güney, Bekir; Dilay, Yusuf; Solomon, M. M.; Gerengi, Hüsnü; Özkan, Adem; Yıldız, Mesut
30MnB5 boron alloyed steel surface is coated using different coating techniques, namely 60(Ni-15Cr-4.4Si-3.5Fe-3.2B 0.7C)-40(WC 12Co) metallic powder plasma spray, Fe-28Cr-5C-1Mn alloy wire arc spray, WC-10Co-4Cr (thick) powder high velocity oxy-fuel (HVOF), and WC-10Co-4Cr (fine) diamond jet HVOF. The microstructure of the crude steel sample consists of ferrite and pearlite matrices and iron carbide structures. The intermediate binders are well bonded to the substrate for all coated surfaces. The arc spray coated surface shows the formation of lamellae. The cross-section of HVOF and diamond jet HVOF coated surfaces indicates the formation of WC, W2C Cr, and W parent matrix carbide structures. The corrosion characteristic of the coated steel has been investigated in 3.5 wt.% NaCl solution using electrochemical impedance spectroscopy (EIS), scanning electron microscope (SEM), and energy dispersive X-ray spectroscopy (EDAX) techniques. The results reveal that the steel corroded in the medium despite the coatings. However, the extent of corrosion varies. HVOF coated sample demonstrated the highest corrosion resistance while arc spray coated sample exhibited the least. EDAX mapping reveals that the elements in the coatings corroded in the order of their standard electrode potential (SEP). Higher corrosion resistance of HVOF coated sample is linked to the low SEP of tungsten.
Determining the Energy Use Efficiency (EUE) and Greenhouse Gas Emissions (GHG) of chickpea production
(Parlar Scientific Publications (P S P), 2021) Dilay, Yusuf
In this research, energy use efficiency (EUE), specific energy (SE), energy productivity (EP), net energy (NE), energy types, GHG emission and GHG ratio computations were determined. This research was conducted during the 2017-2018 production season in Karaman province of Turkey. Trials and research data computations include the 2017-2018 production season. Energy input (EI) in chickpea production were computed as 8223.94 MJ ha(-1), energy output (EO) was computed as 7686.88 MJ ha(-1). In chickpea production, 46.35% of the energy inputs consists of diesel fuel energy (3812.19 MJ ha(-1)). 22.39% consists of chemical fertilizers energy (1841.40 MJ ha(-1)), 18.84 % consists of seed energy (1549.04 MJ ha(-1)), 7.24% consists of machinery energy (595.51 MJ ha(-1)), 3.37% consists of chemicals (fungicide, insecticide) energy (276.84 MJ ha(-1)) and 1.81% consists of human labour energy (148.96 MJ ha(-1)). EUE, SE, EP and NE in chickpea production were computed as 0.93, 5.56 MJ kg(-1), 0.18 kg MJ(-1) and -537.06 MJ ha(-1,) respectively. The total energy input used in chickpea production can be classified as 48.17% direct, 51.83% indirect, 20.65% renewable and 79.35% non-renewable. Total GHG emissions were computed as 1073.72 kgCO(2)-eqha(-1) for chickpea production with the greatest input part for seed use (60.40%). The seed use followed up diesel fuel use (17.40%), nitrogen use (7.66%), phosphorous use (5.06%), labour use (4.95%), machinery use (3.94%), fungicide use (0.35%) and insecticide use (0.24%), respectively. Additionally, GHG ratio value was computed as 0.74 kgCO(2)-eqkg(-1) in chickpea production.
Microstructure and wear properties of WC-10Co-4Cr coating to cultivator blades by DJ-HVOF
(Ice Publishing, 2021) Dilay, Yusuf; Güney, Bekir; Özkan, Adem; Öz, Ali
The friction force in mechanical systems not only reduces their efficiency but also causes wear in the machine components, resulting in financial losses. As in every sector, in agricultural production, the problem of abrasion, particularly in soil tillage, is extremely important. Studies have been conducted examining the different methods for minimizing wear on tillage machinery. In this study, the cultivator blades of a boron-alloyed 30MnB5 steel substrate were coated with WC-10Co-4Cr ceramic powder by way of the Diamond Jet high-velocity oxygen-fuel (DJ-HVOF) technique. The microstructure of the sample and its wear properties under field conditions were then investigated. The microstructure, porosity, hardness, surface roughness and wear properties of the samples were revealed. The coating was observed to be well bonded, both mechanically and metallurgically, and the hardness of the coating was three times higher than that of the uncoated substrate material. In the field trials, the wear was found to be six times lower due to the hardness of the WC-10Co-4Cr coating and the hard carbide phases in its microstructure. As a result, the HVOF coating was shown to minimize wear, which is a big problem in tillage machinery. This can extend the economic life of machinery and make agricultural production more efficient.
Energy input-output analysis of apple production in Turkey: A case study for Karaman province
(Springer Science and Business Media Deutschland GmbH, 2021) Dilay, Yusuf; Özkan, Adem; Özkan, Adem; Gülcan, Bayezid
The aim of this research was to investigate the energy input-output analysis of apple produced in Karaman province of Central Anatolian Region in Turkey. This research was conducted at the apple cultivating facilities during the 2016 and 2017 production seasons in Karaman province. Production data of this research were collected in 2018. In order to determine the energy use efficiency of apple cultivation, various surveys were conducted at the 180 apple farms located in Karaman and selected through Simple Random Sampling method. The data were collected by face to face questionnaires and observations. The agricultural input and output energies used in apple cultivation were calculated to determine the energy input-output analysis. The energy input and output values in apple production were calculated as 78,378.08 MJ ha−1 and 99,959.60 MJ ha−1, respectively. Based on these research findings, the energy inputs in apple cultivation were 15,364.70 MJ ha−1 (19.60%) chemical fertilizers energy, 31,623.70 MJ ha−1 (40.35%) diesel fuel energy, 13,864.40 MJ ha−1 (17.69%) chemicals energy, 6998.40 MJ ha−1 (8.93%) machinery energy, 5738.88 MJ ha−1 (7.32%) human labor energy 2016 MJ ha−1 (2.57%) irrigation water energy and 2772.00 MJ ha−1 (3.54%) electricity energy, respectively. Yield output energy of apple production was calculated as 99,959.60 MJ ha−1. The energy productivity, specific energy, energy use efficiency and net energy calculations were also calculated as 0.54 kg MJ−1, 1.84 MJ kg−1, 1.28 and 21,581.52 MJ ha−1, respectively. © 2021, Springer-Verlag GmbH Deutschland, ein Teil von Springer Nature.
Turkish adaptation of the spirit at work scale in production sector employees
(Springer, 2021) Kırklıkçı, Ahmet Bora
The purpose of workplace spirituality is to enable individuals to realize the potential or their personal spirituality, develop a positive attitude and be able to create positive connections with their environment. The Spirit at Work Scale (SAWS) developed by Kinjerski and Skrypnek stands out as it conceptualizes and evaluates workplace spirituality. This study was organized methodologically in order to assess the validity and reliability of the Turkish adaptation of the Spirit at Work Scale in production businesses in a Turkish metropolitan center. The population of the study was drawn from businesses with ten or more employees in an industrial zone. The study involved a convenience sample of 188 participants. Considering the results of exploratory factor analysis (EFA), it was seen that the items in the scale were grouped around three different factors. According to the results from confirmatory factor analysis (CFA), three-factor SAWS‑TR was confirmed as a model. Consequently, it was seen that spirituality at work combined three elements, namely Engaging Work, Mystical Experience and Spiritual and Social Connection, for workers in the production sector in this study.
Determining the energy utilization and greenhouse gas emissions (GHG) of quinoa production
(Parlar Scientific Publications, 2021) Dilay, Yusuf; Gökdoğan, Osman
In this research, energy output-input ratio, specific energy, energy productivity, net energy, energy type, GHG emission and GHG ratio calculations were performed. This research was performed during the 2018 production season in Karaman province of Turkey. Trials and research data calculations contain the 2018 production season. Energy inputs in quinoa production were calculated as 5543.77 MJ ha(-1), energy output was calculated as 10467.47 MJ ha(-1). In quinoa production, 42.46% of the energy inputs consists of diesel fuel energy (2353.76 MJ ha(-1)), 29.16% consists of chemical fertilizers energy (1616.40 MJ ha(-1)), 18.94% consists of organic fertilizer energy (1050 MJ ha(-1)), 4.34% consists of machinery energy (240.50 MJ ha(-1)). 3.32% consists of seed energy (184.10 MJ ha(-1)), 0.91% consists of chemicals energy (50.60 MJ ha(-1)) and 0.87% consists of human labour energy (48.41 MJ ha-(-1)). Energy use efficiency, specific energy, energy productivity and net energy in quinoa production were calculated as 1.89. 2.77 MJ kg(-1), 0.36 kg MJ(-1) and 4923.70 MJ ha(-1). respectively. The utilized total energy input in quinoa production could be classified as 43.33% direct, 56.67% indirect, 23.33% renewable and 76.87% non-renewable. Total GHG emissions were calculated as 382.42 kgCO(2)-eqha(-1) for quinoa production with the greatest input part for chemical fertilizers (nitrogen, phosphorous) usage (35.70%). The chemical fertilizers usage followed up diesel fuel usage (30.17%), seed usage (19.95%), human labour usage (4.52%), machinery usage (4.47%), organic fertilizer usage (3.37%) and chemicals usage (1.82%), respectively. Additionally, GHG ratio value was calculated as 0.19 kgCO(2)-eqkg(-1) in quinoa production.
Pin loading effect on 3D spacer fabric-laminated composites produced vacuum infusion
(SAGE Publications Ltd., 2022) Erdem, Sumeyye; Kaman, Mete Onur
In this study, pin-loading behavior of laminated composites reinforced with three-dimensional (3D) spacer fabric was investigated, experimentally. Failure loads and modes of 3D-woven glass fiber epoxy composites, which are mostly preferred in automotive, machinery, and building production, are determined and compared with the mechanical properties of two-dimensional (2D)-woven fabric-reinforced composite materials. For this purpose, 2D plane and 3D spacer fabric composite plates were produced using the vacuum infusion method. The effect of pin geometry on joint strength and failure mechanism of composite was determined by tensile tests using test apparatus of single and two serial pin joint. In addition, low velocity impact tests of 2D and 3D plates were performed to explain the failure behavior. For mono-layer 3D-woven fabrics, the existence of out-of-plane fiber increases failure strength up to 50% compared to 2D fabrics. On the other hand, the use of multi-layer 3D fabric does not affect changes-specific failure load according to 2D fabrics significantly. Increasing in the specific load is only 9% for two-layers 3D. This situation has also been observed in impact tests.
Development study of perceived institutionalization and perceived performance scales
(Journal Drvna Industrija, 2021) Kırklıkçı, Ahmet Bora; Gedik, Tarık
Institutionalization is necessary for corporations to prevent economic, financial, legal, administra-tive, and technical chaos and thus improve performance. The concept of performance is the most supporting tool in conducting the control function in business management. While the amount of input and products in the forest industry in Turkey is rising, institutionalization is inadequate. This study attempts to methodologically develop and test scales for perceived institutionalization and perceived performance in furniture and panel businesses, which are two sub-sectors of the forest industry. Data was obtained in 35 cities between March and July 2017, through face-to-face interviews with 797 employees in 462 furniture businesses and 31 panel businesses. In the analysis of the study, content validity of the scales was evaluated through expert opinion and initial application, while construct validity was assessed by EFA and CFA. Cronbach alpha coefficient, CR, and AVE were used to evalu-ate reliability, while the suitability of perceived institutionalization and performance scale model was assessed through SEM. The scales have high reliability and validity, and an improvement in the institutionalization level of a business will result in improvements in performance (r=0.98). Through this methodological study, scales for perceived institutionalization and perceived performance in furniture and panel businesses operating in Turkey and the relationship between perceived institutionalization and perceived performance were explained by a model. © 2021 by the author(s). Licensee Faculty of Forestry and Wood Technology, University of Zagreb.

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