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Copyright of Mersin University School of Medicine Lokman Hekim Journal of History of Medicine & Folk Medicine is the property of Mersin University School of Medicine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Structural materials and their properties in different applications with next-generation composite production techniques are quite promising areas. In this study, new composite blocks were produced with the addition of industrial and recycled steel fibers to high strength cementitious composites (HSCCs). The vibrational damping capabilities of the blocks produced in standard dimensions (16 cm × 4 cm × 4 cm) were tested by using the modal analysis method. In many different applications, structural materials are expected to absorb vibrations such as earthquakes or artificial vibrations from machine systems operating in industrial areas. In this study, the vibration damping capability of HSCCs was investigated and improved by adding steel fiber to HSCCs. The experimental study shows that adding steel fibers improves the bending stress by up to 127% and damping ratio over 200%. The fiber size and distribution play a significant role in this improvement. This effect was also achieved to a certain extent in the samples produced using recycled steel fibers obtained from waste tires. In this way, the vibration damping ability of the HSCCs is increased with an environmentally friendly approach. [ABSTRACT FROM AUTHOR]

This study investigated the corrosion behavior of cryogenically treated Ti6Al4V alloys in an isotonic solution. Samples were subjected to shallow or deep cryogenic treatment, and some samples then underwent an aging procedure. They were characterized by microstructural analysis, an open circuit potential test, an electrochemical impedance method, and a potentiodynamic test. The polarization tests demonstrated that the deep cryogenic treatment shifted the corrosion potential to more anodic values compared to the untreated sample. For all treated samples, it was found that the corrosion current densities were lower than those in the untreated sample, and the lowest current densities were registered for the sample subjected to deep cryogenic treatment for 36 hr. The shallow cryogenic treated samples and the sample aged without cryogenic treatment showed semicapacitive loops with poor corrosion impedance compared to the untreated sample, whereas deep cryogenic treatment produced Warburg impedance with diffusion in the solid phase. [ABSTRACT FROM AUTHOR]

In this study, different non-traditional turning operations were investigated using various soft computing methods. In these operations, cutting speed, machining method, material type and tool overhang lengths were used as machining inputs. Surface roughness, stable cutting depths and maximum cutting tool temperatures were considered as machining outputs. In the first stage, artificial neural network, classification and regression tree (CART) and support vector machine models were developed to predict these outputs. In the second stage, an optimization study (regression analysis) was conducted. CART model produced better prediction results compared to the other methods. In CART models; 0.991, 0.998 and 0.959 values of correlation coefficients were calculated for the prediction of surface roughness, stable cutting depth and maximum cutting tool temperatures, respectively. In the optimization study, ultrasonic assisted/hot ultrasonic assisted turning methods, a tool overhang length of 60 mm and a cutting speed of 10 m/min provide optimum conditions. The proposed soft computing models will help to understand the effect of various parameters in non-traditional machining methods. These models will give a preliminary idea before the experiments. These models can be used as an alternative instead of 2D finite element machining simulations. Less analysis time is required compared to the finite element simulations. [ABSTRACT FROM AUTHOR]

In the present study, different turning operations (conventional, ultrasonic-assisted and hot ultrasonic-assisted operations) of Ti6Al4V alloy were investigated by using a new multi-criteria decision-making method. In the first part of the study, conventional turning, UAT and HUAT operations were conducted, and they were compared to each other. The modal/chatter tests were performed through a hammer and recording chatter sound. Cutting velocity (10–40 m/min) and cutting tool overhang lengths (60 and 70 mm) were used as cutting parameters in the experiments. The full factorial experimental design was used. In the comparison of the turning operations, surface roughness, stable cutting depths and maximum cutting tool temperatures were considered. Also, variance analysis was carried out to optimize machining outputs. In addition, chip formation was observed. In the second part of the study, multi-criteria decision-making (MCDM) analysis was performed by using reference ideal method which has been recently presented in the literature to optimize machining outputs. Surface roughness, stable cutting depths and maximum cutting tool temperatures were selected as criteria to rank all the experiments. Based on MCDM results, higher cutting speeds, lower tool overhang lengths and ultrasonic-assisted turning are the appropriate levels of the cutting parameters. As a result, this study helps to understand new non-traditional machining methods in terms of MCDM perspective. [ABSTRACT FROM AUTHOR]

In this article, a novel method is suggested for solving heuristic optimization problems. A pre-study was performed to define proper bounds. Different problems with these bounds were solved using genetic, accelerated particle swarm, and cuckoo search algorithms. Three different problems (multi-pass turning, welded beam design, and tension spring) were used as case studies. The results of the studies were compared with the earlier studies. As a result, the proposed method requires less computing time and has better objective function values compared to the solutions in the literature. The proposed method provides effective decision-making for operators and engineers dealing with different design and manufacturing environments in terms of cost and time. [ABSTRACT FROM AUTHOR]

Titanium alloys exhibit superior properties such as high strength-to-weight ratio and corrosion resistance but these alloys possess poor machinability. To overcome this disadvantage, new machining methods (Ultrasonic Assisted Machining, Hot Machining etc.) are developed. Hot Ultrasonic Assisted Turning (HUAT) is a new machining method which changes the cutting system between tool and workpiece therefore reduced cutting forces and better surface finish for workpiece are obtained. In this study, 2D finite element (FE) analysis was carried out to investigate the effects of HUAT for titanium alloys. It was confirmed that HUAT technique reduces cutting forces and effective stress significantly but cutting temperature increases compared to conventional turning. [ABSTRACT FROM AUTHOR]

Background and aim: A Z-plasty flap is one of the most widely used geometric relaxation methods to release contracture bands. A rhomboid flap is a lesser used geometric relaxation method than a Z-plasty flap. This study aimed to determine the length and rate of elongation provided by rhomboid and Z-plasty flaps. Methods: Bilateral contracture bands were created in the inguinal skins of rats. A rhomboid flap was planned for the right side of the inguinal region, and a single Z-plasty flap was planned for the left side. The length and rate of elongation provided by the two flaps were calculated after completing the procedures and were compared using Student’s t-test. Results: Experimental contracture bands disappeared in both the inguinal regions after creating rhomboid and Z-plasty flaps. The mean postoperative elongation of the contracture band was 1.4 ± 0.119 and 2.47 ± 0.281 cm using the rhomboid and Z-plasty flaps, respectively. The difference was statistically significant (p < .001). Conclusion: Z-plasty flaps provide more elongation than rhomboid flaps and also appear to be better options for releasing linear contracture bands. However, rhomboid flaps may be used as alternatives when Z-plasty flaps cannot be used and in regions such as the axilla, genital region, nipple-areola, where their distortion effects should be avoided. [ABSTRACT FROM AUTHOR]

Ultrasonic-assisted machining is a machining operation based on the intermittent cutting of material which is obtained through vibrations generated by an ultrasonic system. This method utilizes low-amplitude vibrations with high frequency to prevent continuous contact between a cutting tool and a workpiece. Hot machining is another method for machining materials which are difficult to cut. The basic principle of this method is that the surface of the workpiece is heated to a specific temperature below the recrystallization temperature of the material. This heating operation can be applied before or during the machining process. Both of these operations improve machining operations in terms of workpiece-cutting tool characteristics. In this study, a novel hybrid machining method called hot ultrasonic-assisted turning (HUAT) is proposed for the machinability of Hastelloy-X material. This new technique combines ultrasonic-assisted turning (UAT) and hot turning methods to take advantage of both machining methods in terms of machining characteristics, such as surface roughness, stable cutting depths, and cutting tool temperature. In order to observe the effect of the HUAT method, Hastelloy-X alloy was selected as the workpiece. Experiments on conventional turning (CT), UAT, and HUAT operations were carried out for Hastelloy-X alloy, changing the cutting speed and cutting tool overhang lengths. Chip morphology was also observed. In addition, modal and sound tests were performed to investigate the modal and stability characteristics of the machining. The analysis of variance (ANOVA) method was performed to find the effect of the cutting speed, tool overhang length, and machining techniques (CT, UAT, HUAT) on surface roughness, stable cutting depths, and cutting tool temperature. The results show both ultrasonic vibration and heat improve the machining of Hastelloy-X. A decrease in surface roughness and an increase in stable cutting depths were observed, and higher cutting tool temperatures were obtained in UAT and HUAT compared to CT. According to the ANOVA results, tool overhang length, cutting speed, and machining techniques were effective parameters for surface roughness and stable cutting depths at a 1% significance level (p ≤ 0.01). In addition, cutting speed and machining techniques have an influence on cutting tool temperature at a 1% significance level (p ≤ 0.01). During chip analysis, serrated chips were observed in UAT and HUAT. [ABSTRACT FROM AUTHOR]