A Methodology to Determine the Friction Coefficient in Flexforming (Fluidcell Forming) Process

H.Ali Hatipo?lu,Naki Polat,Arif Koksal 한국소성가공학회 2010 기타자료 Vol.2010 No.6

In this study, it is aimed to determine the friction coefficient between die surface and blank in flexforming (fluidcell forming) process in which a pressurized rubber diaphragm is used to form the sheet. An aluminum square pan is chosen for the workpiece and it is drawn at various pressures and friction conditions (with lubricant, without lubricant, etc.). Numerical models of the process are established with different friction coefficients and results are then compared with the experiments in order to determine the corresponding coefficients of the friction conditions. The displacement of the flange edge is used for comparison.

Maxillary expansion with the memory screw

Koray Halicio?lu,Ali Kiki,?brahim Yavuz 대한치과교정학회 2012 대한치과교정학회지 Vol.42 No.2

Objective: The purpose of this study was to investigate the effects of a newly developed rapid maxillary expansion screw-the memory screw-over 6 months. Methods: Five subjects, aged between 11.7 and 13.75 years, were enrolled in this study. All subjects underwent placement of a maxillary expansion appliance containing superelastic nickel-titanium open-coil springs in its screw bed. The parents of the patients and/or the patients themselves were instructed to activate the expansion screw by 2 quarter-turns 3 times a day (morning, midday, and evening; 6 quarter-turns a day). The mean expansion period was 7.52 ± 1.04 days. Dentoskeletal effects of the procedure, including dentoalveolar inclination, were evaluated. Measurements of all the parameters were repeated after 6 months of retention in order to check for relapse. Results: Sella-Nasion-A point (SNA) and Sella-Nasion/Gonion-Menton angles increased, and Sella-Nasion-B point (SNB) angle decreased in all the subjects during the expansion phase. However, they approximated to the initial values at the end of 6 months. On the other hand, the increments in maxillary apical base (Mxr-Mxl) and intermolar widths was quite stable. As expected, some amount of dentoalveolar tipping was observed. Conclusions: The newly developed memory expansion screw offers advantages of both rapid and slow expansion procedures. It widens the midpalatal suture and expands the maxilla with relatively lighter forces and within a short time. In addition, the resultant increments in the maxillary apical base and intermolar width remained quite stable even after 6 months of retention.

Braking performance and noise in excessive worn brake discs coated with HVOF thermal spray process

Ali Öz,Habib Gürbüz,Ali Kemal Yakut,Selami Sağiroğlu 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.2

In this paper, two excessive worn brake discs of a light commercial vehicle were coated with High velocity oxygen fuel (HVOF) thermal spray process for reuse. The coated discs were compared with uncoated Original equipment manufacturer (OEM) D1 disc in terms of braking performance and noise. The D2 disc was coated with tungsten-carbide-cobalt (88 %WC-12 %Co) powder and NiCr (80/20) binder, and 500 µm thick coating was obtained. The D3 disc was coated with Colmonoy-88 (Ni-W-Cr-B-Si) powder and NiCr (80/20) binder and 600 µm thick coating was obtained. Several test procedures (e.g. bedding, vibration, and structural-strength tests) was applied to three discs using inertia brake dynamometer. Results showed that coated D2 disc with tungsten carbide cobalt provided lower brake noise and higher brake performance compared with OEM disc. Considering the coefficient of friction and temperature, coated D3 disc has approximately equal braking performance with OEM D1 disc despite the high braking noise value.

Effect of Strontium and Magnesium Additions on the Microstructure and Mechanical Properties of Al–12Si Alloys

Ali Paşa Hekimoğlu,Merve Çalış,Gizem Ayata 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.6

In this study, a binary Al–12Si, eight ternary Al–12Si–Sr, and six quaternary Al–12Si–0.1Sr–(0.2–1)Mg alloys were producedby permanent mold casting. It was observed that microstructure of the binary alloy consisted of the phases of aluminum richα grains (dendrites), primary silicon, plate like β and eutectic Al–Si containing needle like silicon particles. The ternaryalloys have fine and globular (modified) eutectic silicon particles and higher volume fraction of α (Al) dendrites than binaryalloys. They also contained Al4Srphase after 0.02 wt% Sr, in addition to the phases in the binary alloy. This phase got coarsewhen the strontium ratio exceeded 0.1%. It was observed that the plate like β phase seen in the binary alloys transformed intothe fibrous form δ phase in the ternary alloys. Magnesium addition resulted in transformation of δ phase into script like πphase, and the formation of lamellar like Mg2Siphase when the ratio of it in the quaternary alloys reached the 0.6 wt%. Thelamellar like form of Mg2Siphase changed to Chinese-script type after the 0.6 wt% Mg. The results showed that hardness,yield and tensile strength of the Al–12Si–Sr alloys increased with increasing strontium content up to 0.1 wt%. The resultsalso showed that hardness of the quaternary alloys increased with increasing magnesium content, while yield and tensilestrength increased only up to 0.6 wt% Mg.

Unusual Malignant Solid Neoplasms of the Kidney: Cross-Sectional Imaging Findings

Ali Devrim Karaosmanog˘lu,Mehmet Ruhi Onur,Ali Shirkhoda,Mustafa Ozmen,Peter F. Hahn 대한영상의학회 2015 Korean Journal of Radiology Vol.16 No.4

Malignant kidney neoplasms are the most frequently encountered solid kidney masses. Although renal cell carcinoma is the major renal malignancy, other solid malignant renal masses should be considered in the differential diagnosis of solid renal masses that do not contain a macroscopic fatty component. In this pictorial essay, we present the imaging findings of a primitive neuroectodermal tumor, primary liposarcoma of the kidney, primary neuroendocrine tumor, leiomyosarcoma, synovial sarcoma, malignant fibrous histiocytoma, sclerosing fibrosarcoma and renal metastasis of osteosarcoma.

Assessing the Formation of Polycyclic Aromatic Hydrocarbons in Grilled Beef Steak and Beef Patty with Different Charcoals by the Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) Method with Gas Chromatography–Mass Spectrometry

Ali Samet Babaoğlu 한국축산식품학회 2023 한국축산식품학회지 Vol.43 No.5

This study investigated the effects of different charcoals on the occurrence of 16 polycyclic aromatic hydrocarbons (PAHs) in grilled beef steaks and beef patties. Seven different charcoals were used as follows: from oak wood (C1), from orange wood (C2), from Valonia oak wood (C3), from Marabu wood (C4), extruded charcoal from beech wood (C5), from coconut shells (C6), and from hazelnut shells (C7). The grilling times for each charcoal type were 6 min for the beef patties and 7 min for the beef steaks, until the internal temperature reached at least 74℃. The total concentration of 16 PAHs (PAH16) in beef steaks grilled with C1 (35.75 μg/kg) and C7 (36.39 μg/kg) was higher than that of C3 (23.80 μg/kg) and C6 (24.48 μg/kg; p<0.05). The highest amounts of PAH16 (216.40 μg/kg) were determined in the beef patty samples grilled using C5 (p<0.05). The summation of benzo[a]anthracene, chrysene, benzo[b]fluoranthene and benzo[a]pyrene, referred to as PAH4, was not detected in any of the beef steaks, whereas it was determined in the beef patties grilled with C2 (7.72 μg/kg) and C5 (22.95 μg/kg; p<0.05). The PAH16 concentrations of the beef patty samples in each charcoal group were significantly higher compared to the beef steaks (p<0.05). To avoid the formation of high PAH levels, the use of extruded charcoal and hazelnut shell charcoal should therefore be avoided when charcoal grilling beef steaks and beef patties, and low-fat meat products should be preferred.

Numerical approaches for vibration response of annular and circular composite plates

Ali Kemal Baltacıoğlu,Ö mer Civalek 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.29 No.6

In the present investigation, by using the two numerical methods, free vibration analysis of laminated annular and annular sector plates have been studied. In order to obtain the main equations two different shell theories such as Love's shell theory and first-order shear deformation theory (FSDT) have been used for modeling. After obtaining the fundamental equations in briefly, the methods of harmonic differential quadrature (HDQ) and discrete singular convolution (DSC) are used to solve the equation of motion. Accuracy, convergence and reliability of the present HDQ and DSC methods were tested by comparing the existing results obtained by different methods in the literature. The effects of some geometric and material properties of the plates are investigated via these two methods. The advantages and accuracy of the HDQ and DSC methods have also been examined with different grid numbers and shell theory. Some results for laminated annular plates and laminated circular plates were also been supplied.

Effect of MAP and Vacuum Sealing on Sensory Qualities of Drysalted Olive

Nurcan Değirmencioğlu,Ozan Gürbüz,Ali Değirmencioğlu,Yasemin Şahan,Hasan Özbey 한국식품과학회 2011 Food Science and Biotechnology Vol.20 No.5

The ‘Gemlik’ olive, grown in Turkey, is the main variety used in the production of commercial table olives. The aim of the present work was to determine the effect on sensory qualities of dry-salted olives of the ‘Gemlik’ cultivar packed with vacuum sealing or modified atmosphere packaging and stored at 4 or 20^oC. Storage temperature did not have a significant effect on the sensory profile (p>0.05). However, with the exception of the color attribute, somewhat higher overall scores were given to samples stored at 4^oC. In both vacuum sealing and modified atmosphere packaging (MAP) samples stored at 4^oC, the lack of oxygen and dipping the olives in 10 ppm chlorine solution before dry-salting, prevented the growth of yeast and mold and therefore both rancidity and softness attributes scored higher points by panelists.

Wood Anatomy of Mangifera indica L.(Anacardiaceae)

Lu, Sun,Ahmed, Sheikh Ali,Chong, Song-Ho Korea Furniture Society 2006 한국가구학회지 Vol.17 No.3

The wood anatomy of Mangifera indica belonging to the species of Anacardiaceae native to Bangladesh was described. The species of this family was distinctive in having growth rings, thin-to thick-walled, nonseptate libriform fibres, vessels with simple perforation plate and nonvestures intervessel pittings. Paratracheal axial parenchyma was vasicentric, lozenge-aliform and confluent. Axial parenchyma band more than 3 cells wide and in marginal or in seemingly marginal bands. 3-4 cells per axial parenchyma was dominantly present. Ray height was less than 1mm. Body ray cells were procumbent with one row of upright and square marginal cells. More than one prismatic crystals of about the same size was present in upright or square ray cells.

Is the Reference Electrode Location Important for the Electromyography Evaluation of the Pelvic Floor in Urodynamic Studies?

Ali Tekin,Murat Pehlivan,Sibel Tiryaki,Ömer Barış Yücel,Uygar Bağcı,Hasan Çayırlı,İlker Zeki Arusoğlu,İbrahim Ulman 대한배뇨장애요실금학회 2022 International Neurourology Journal Vol.26 No.4

Purpose: Perineal electromyography (EMG) is a crucial part of urodynamic studies. Many researchers focused on the standardization of techniques in urodynamics, but no study has yet evaluated the differences with various reference electrode placements. The aim of this study was to determine the optimal placement of the reference electrode for recording pelvic floor activity in urodynamic studies. Methods: Children over 6 years of age without anatomic or neurological abnormalities were invited to participate in the study. Four reference electrodes were placed on the right kneecap, the inner surface of the right inner thigh, the right anterior iliac spine (AIS), and the skin over the left gluteal muscles for simultaneous recording. The EMG signal formed by pelvic contraction during forceful straining was recorded both in the supine and sitting positions. The root mean square (RMS) value of each muscle contraction signal was calculated. Results: Twenty-one participants (10 boys and 11 girls) were included. The mean age was 10.19±3.20 years. The highest RMS values were obtained with the reference electrode on the thigh in the supine position and the AIS in the sitting position. Significant differences were found between the mean RMS values of the knee and other locations of reference electrodes in the supine position, as well as between mean RMS values in all regions except the thigh and gluteus in the sitting position. The minimum mean RMS values in both positions were obtained with the reference electrode on the knee. Conclusions: During urodynamic studies, reference electrodes shall be placed on AIS in the sitting and on the inner thigh in the supine position. The knee is not a suitable option for reference electrode placement. This information may help improve EMG recordings in the evaluation of pelvic floor muscles.