A new type notched slab approach for timber-concrete composite construction: Experimental and numerical investigation

Semih Yılmaz,Olguhan Şevket Karahasan,Ahmet Can Altunışık,Nilhan Vural,Serhat Demir 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.81 No.6

Timber-Concrete Composite construction system consists of combining timber beam or deck and concrete with different connectors. Different fastener types are used in Timber-Concrete Composite systems. In this paper, the effects of two types of fasteners on structural behavior are compared. First, the notches were opened on timber beam, and combined with reinforced concrete slab by fasteners. This system is called as Notched Connection System. Then, timber beam and reinforced concrete slab were combined by new type designed fasteners in another model. This system is called as Notched-Slab Approach. Two laboratory models were constructed and bending tests were performed to examine the fasteners' effectiveness. Bending test results have shown that heavy damage to concrete slab occurs in Notched Connection System applications and the system becomes unusable. However, in Notched-Slab Approach applications, the damage concentrated on the fastener in the metal notch created in the slab, and no damage occurred in the concrete slab. In addition, non-destructive experimental measurements were conducted to determine the dynamic characteristics. To validate the experimental results, initial finite element models of both systems were constituted in ANSYS software using orthotropic material properties, and numerical dynamic characteristics were calculated. Finite element models of Timber-Concrete Composite systems are updated to minimize the differences by manual model updating procedure using some uncertain parameters such as material properties and boundary conditions.

Investigation of Relaxin-3 Serum Levels in terms of Social Interaction, Communication, and Appetite as a Biomarker in Children with Autism

Semih Erden,Kevser Nalbant,İ,brahim Kılınç 대한정신약물학회 2022 CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE Vol.20 No.1

Objective: To investigate the possible relationship between relaxin-3 and autism spectrum disorder (ASD). Methods: Serum relaxin-3 was measured in 80 children (50 children diagnosed with ASD and 30 controls). Symptom severity in the ASD group was evaluated by the Childhood Autism Rating Scale (CARS). Behavioral and nutritional problems in the groups were evaluated using the Abnormal Behavior Checklist (ABC) and the Children s Eating Behavior Questionnaire (CEBQ). Results: Our findings showed that serum relaxin-3 levels were higher in children with ASD than in the controls. The listening response sub-scale score of the CARS scale was found to decrease as the level of relaxin-3 increased. However, as relaxin-3 levels increased in children with ASD, it was found that the speech problem sub-scale score on the ABC scale and the desire to drink score on the CEBQ scale increased, but the satiety responsiveness and food fussiness scores decreased. Conclusion: This study the first to investigate serum levels of relaxin-3, which has a role in regulating social behavior and nutritional behavior in children with ASD.

Correction of node mapping distortions using universal serendipity elements in dynamical problems

Semih Küçükarslan,Ali Demir 국제구조공학회 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.40 No.2

In this paper, the use of universal serendipity elements (USE) to eliminate node mapping distortions for dynamic problem is presented. Rectangular shaped elements for USE are being introduced by using a flexible master element with an adjustable edge node location. The shape functions of the universal serendipity formulation are used to derive the mass and damping matrices for the dynamic analyses. These matrices eliminate the node mapping distortion errors that occurs incase of the standard shape function formulations. The verification of new formulation will be tested and the errors encountered in the standard formulation will be studied for a dynamically loaded deep cantilever.

Chemical, Textural and Sensorial Attributes of Biltong Produced through Different Manufacturing Processes

Semih Engez,Pelin Baskan,Bülent Ergönül 한국축산식품학회 2012 한국축산식품학회지 Vol.32 No.3

Six different types of biltong samples were manufactured from beef which was slowly frozen, quickly frozen or unfrozen. After marinating the samples according to the formulation used, meats were dried at two different temperatures (28±1oC or 42±1oC) until they lost half of their weights. Chemical, instrumental textural and sensorial analyses were done for determination of the most preferred sample and to compare the attributes of the samples with each other. It was found that, aw values of the samples were among 0.81 and 0.83, whereas water contents were changing among the values 39.64% and 45.37%. There were no significant differences determined among the protein contents of the biltong samples (p>0.05). Fat, ash and salt contents of the samples were among the values 1.32% and 2.07%, 5.30% and 6.06%, 2.68% and 3.30% respectively. Hardness of the samples were found between 34.81 N and 44.13 N and there was no significant difference observed among the hardness values of the biltong samples (p>0.05). As results of the analyses, it can be concluded that the highest flavor,color, tenderness and overall acceptability scores were obtained for the sample QF-LT which was made from quickly frozen beef and was dried at low temperature (28±1oC) (p<0.05).

The Effect of Curing and Post-curing Processes on Physical and Mechanical Behaviors of Jute Fabric Reinforced AESO/Epoxy Based Bio-composites

Semih Ozkur,Hande Sezgin,Ipek Yalcin-Enis 한국섬유공학회 2022 Fibers and polymers Vol.23 No.5

Today, depending on the interest in finding ways to reduce dependence on fossil raw materials, the search foralternative bio-based materials to these raw materials is increasing. In this respect, thermoset resin composite materials,which are relatively difficult to recycle and leave large amounts of waste behind, draw attention when it comes tosustainability. This situation highlights the importance of the studies carried out to use bio-based thermoset resins in the mosteffective way, instead of petroleum-based resins. For the biocomposites produced in this study, a more sustainable resinsystem is optimized by adding acrylated epoxized soybean oil (AESO) to epoxy resin. Jute fabric reinforced composites areproduced by vacuum infusion method, and the effect of adding different amounts of AESO (0, 30, 50, 70, 100 % wt.) toepoxy resin on the properties of the composite is examined by changing the curing (20 °C, 90 °C), and post-curing (120 °C)temperatures. Charpy and drop-weight impact resistance, flexural and tensile strength properties are tested, as well asmeasuring fiber weight ratio, water absorption rate and water contact angle of the samples. The results show that the impactresistance gradually decreases with curing and post-curing processes especially in samples containing 0-50 % AESO resinwhile the flexural strength increases by heat treatment. On the other hand, there is an increment in elastic modulus of pureepoxy samples with curing at 90 ° and post-curing at 120 °C. The water absorption rates of almost all samples have beenreduced by heat treatment and the hydrophobicity of the samples including more than 50 % AESO increases with curing andpost-curing processes.

Experimental investigation of a prefabricated timber-concrete composite floor structure: Notched-slab approach

Yilmaz, Semih,Demir, Serhat,Vural, Nilhan Techno-Press 2021 Advances in concrete construction Vol.12 No.1

This study presents the experimental performance of a high ductility and energy dissipation capacity connector named notched-slab fastener, which is developed for timber-concrete composite floor structures. Notched-slab fastener is unique because the notch was left in the concrete slab instead of a timber beam for the first time. In this way, cross-section loss in the timber beam is prevented. This is one of the most important benefits of the proposed connector. Experimental performance of the purposed connector was investigated with two test methods: push-out test and bending test. For comparison purposes, a notched fastener was also produced and tested as reference sample. Test results showed that notched-slab fastener has stable load carrying behavior under push-out loading with high-energy dissipation and no sudden strength degradation. In addition, notched slab design provided moment arm to the fastener and the damage is concentrated in the connector instead of concrete.

Correction of node mapping distortions using universal serendipity elements in dynamical problems

Kucukarslan, Semih,Demir, Ali Techno-Press 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.40 No.2

In this paper, the use of universal serendipity elements (USE) to eliminate node mapping distortions for dynamic problem is presented. Rectangular shaped elements for USE are being introduced by using a flexible master element with an adjustable edge node location. The shape functions of the universal serendipity formulation are used to derive the mass and damping matrices for the dynamic analyses. These matrices eliminate the node mapping distortion errors that occurs incase of the standard shape function formulations. The verification of new formulation will be tested and the errors encountered in the standard formulation will be studied for a dynamically loaded deep cantilever.

Chemical, Textural and Sensorial Attributes of Biltong Produced through Different Manufacturing Processes

Engez, Semih,Baskan, Pelin,Ergonul, Bulent Korean Society for Food Science of Animal Resource 2012 한국축산식품학회지 Vol.32 No.3

Six different types of biltong samples were manufactured from beef which was slowly frozen, quickly frozen or unfrozen. After marinating the samples according to the formulation used, meats were dried at two different temperatures ($28{\pm}1^{\circ}C$ or $42{\pm}1^{\circ}C$) until they lost half of their weights. Chemical, instrumental textural and sensorial analyses were done for determination of the most preferred sample and to compare the attributes of the samples with each other. It was found that, aw values of the samples were among 0.81 and 0.83, whereas water contents were changing among the values 39.64% and 45.37%. There were no significant differences determined among the protein contents of the biltong samples (p>0.05). Fat, ash and salt contents of the samples were among the values 1.32% and 2.07%, 5.30% and 6.06%, 2.68% and 3.30% respectively. Hardness of the samples were found between 34.81 N and 44.13 N and there was no significant difference observed among the hardness values of the biltong samples (p>0.05). As results of the analyses, it can be concluded that the highest flavor, color, tenderness and overall acceptability scores were obtained for the sample QF-LT which was made from quickly frozen beef and was dried at low temperature ($28{\pm}1^{\circ}C$) (p<0.05).

직접주사 분무 기반 전도성 패턴을 가진 나노섬유 제작

김정화,Semih Akin,이유진,전병국,윤용준,정영훈 한국정밀공학회 2024 한국정밀공학회지 Vol.41 No.4

The demand for flexible electronic materials used in wearable devices has experienced a significant surge in recent years. Wearable devices typically incorporate an electronic material or system that can be mounted on a human body. It is imperative that these materials are composed of substances compatible with the human body. Consequently, numerous studies have been undertaken to develop flexible electronic devices with various performance capabilities. In this study, nanowire patterns were manufactured on nanofibers and utilized as patches. To create a nanowire pattern, a direct-write spraying process was employed to investigate changes in electrical characteristics using process variables. The process involved depositing silver nanowires on the surface of nanofibers using a pneumatic spray nozzle. Generated patterns were found to be suitable for use as sensors capable of withstanding skin-attached deformation

SiC Substrate Effects on Electron Transport in the Epitaxial Graphene Layer

Engin Arslan,Semih Çakmakyapan,Özgür Kazar,Serkan Bütün,Sefer Bora Li esivdin,Neval A. Cinel,Gülay Ertas,Sükrü Ardal,Engin T ras,Jawad-ul-Hassan,E. Janzén,Ekmel Özbay 대한금속·재료학회 2014 ELECTRONIC MATERIALS LETTERS Vol.10 No.2

Hall effect measurements on epitaxial graphene (EG) on SiC substrate have been carried out as a function of temperature. The mobility and concentration of electrons within the two-dimensional electron gas (2DEG) at the EG layers and within the underlying SiC substrate are readily separated and characterized by the simple parallel conduction extraction method (SPCEM). Two electron carriers are identified in the EG/SiC sample: one highmobility carrier (3493 cm2/Vs at 300 K) and one low-mobility carrier (1115 cm2/Vs at 300 K). The high mobility carrier can be assigned to the graphene layers. The second carrier has been assigned to the SiC substrate.