A Review of the Brazeability of Low-Temperature and Nano-Reinforced Al-Based Brazing Filler Metals

Furkan,Kim Hye-Jeong,Gun-hwan Lee,정재필 대한용접·접합학회 2022 대한용접·접합학회지 Vol.40 No.3

Aluminum and its alloys are some of the most widely used materials for the brazing of parts in aerospace and auto- motive industries due to their excellent physical characteristics, e.g., good ductility, high strength-to-weight ratio, light weight, good corrosion and oxidation resistance, satisfactory malleability and formability, and excellent ther- mal and electrical conductivity. Especially during casting operations, high strength and machinability of Al-based al- loys are of utmost concern. The quality and strength of casting products are affected by porosity generated due to the dissolution of gases and the effects of modifiers. Thus, unstable properties of Al alloys arising due to such influen- ces should to be controlled by reinforcing suitable elements. Compared to other materials, brazing on Al requires higher control precision as the difference between the melting points of the base metal and the filler remain low even after the addition of melting point suppressants, such as Si. This necessitates the development of novel low-temper- ature Al-based filler metals. Moreover, the mechanical properties of Al-based alloys can be enhanced by introducing nanoparticles within them to reduce the thickness of Si-needles and IMCs (intermetallic compound) within the Al matrix, thereby refining the nanostructure.

GENERALIZED PELL SEQUENCES RELATED TO THE EXTENDED GENERALIZED HECKE GROUPS H_3;q AND AN APPLICATION TO THE GROUP H_3;3

( Furkan Birol ),( Ozden Koruoglu ),( Recep Sahin ),( Bilal Demir ) 호남수학회 2019 호남수학학술지 Vol.41 No.1

We consider the extended generalized Hecke groups H_3;q generated by X(z) = -(z - 1)^-1, Y (z) = -(z + λ_q)^-1 with λ_q =2 cos(π/q) where q ≥ 3 an integer. In this work, we study the generalized Pell sequences in H_3;q : Also, we show that the entries of the matrix representation of each element in the extended generalized Hecke Group H_3;3 can be written by using Pell, Pell-Lucas and modified-Pell numbers.

Diagnosis of Sarcopenia in Head and Neck Computed Tomography: Cervical Muscle Mass as a Strong Indicator of Sarcopenia

Furkan Ufuk,Duygu Herek,Doğangün Yüksel 대한이비인후과학회 2019 Clinical and Experimental Otorhinolaryngology Vol.12 No.3

Objectives. Patients with head and neck cancer (HNC) have a high risk of sarcopenia, which is associated with poor prognosis. Skeletal-muscle area and index at the third lumbar (L3) vertebra level (L3MA and L3MI) are recommended for the detection of sarcopenia. However, L3 level is not included in many imaging protocols and there are no data for optimal levels and cutoffs for the diagnosis of sarcopenia in head and neck computed tomography (HNCT) scans. Our aim was to assess the relationship between cervical paravertebral muscle values and L3MI and to investigate optimal level to diagnose sarcopenia on HNCTs. Methods. Patients with HNC (n=159) who underwent positron emission tomography-CT for tumor staging were retrospectively analyzed. On CT images, paravertebral and sternocleidomastoid muscle areas at second (C2), third (C3), and fourth (C4) cervical vertebrae levels (C2MA, C3MA, C4MA, SCMA) and L3MA were measured. Cross-sectional areas were normalized for stature (muscle area/height square) and muscle index (C2MI, C3MI, C4MI, SCMI, L3MI) values were obtained. Spearman correlation and linear regression analyses were used for assessing correlations. To calculate the diagnostic performance of SCMI, C2MI, C3MI, and C4MI for the diagnosis of sarcopenia with respect to the cutoffs of L3MI, receiver operating characteristic (ROC) analysis was used. Results. Males had significantly higher muscle areas than females. Although C2MI, C3MI, C4MI, and SCMI values all showed very strong and significant correlation with L3MI (P<0.001). According to the ROC analysis, the best discriminative for sarcopenia was C3MI in males (area under curve [AUC], 0.967) and SCMI in females (AUC, 0.898). Conclusion. C2MI, C3MI, C4MI, and SCMI values can be used as alternatives for the diagnosis of sarcopenia in routine HNCT examinations

Impact of rural residence on the presentation, management and survival of patients with non-metastatic muscle-invasive bladder carcinoma

Furkan Dursun,Ahmed Elshabrawy,Hanzhang Wang,Dharam Kaushik,Michael A. Liss,Robert S. Svatek,John L. Gore,Ahmed M. Mansour 대한비뇨의학회 2023 Investigative and Clinical Urology Vol.64 No.6

Purpose: To assess the impact of rural and remote residence on the receipt of guidelines-recommended treatment, quality of treatment and overall survival (OS) in patients with non-metastatic muscle-invasive bladder cancer (MIBC). Materials and Methods: Patients with MIBC were identified using National Cancer Database. Patients were classified into three residential areas. Logistic regression models were used to assess associations between geographic residence and receipt of radical cystectomy (RC) or chemoradiation therapy (CRT). Models were fitted to assess quality benchmarks of RC and CRT. Results: We identified 71,395 patients. Of those 58,874 (82.5%) were living in Metro areas, 8,534 (11.9%) in urban-rural adjacent (URA), and 3,987 (5.6%) in urban-rural remote to metro area (URR). URR residence was significantly associated with poor OS compared to URA and Metro residence (HR 0.87, 95% CI 0.81–0.94 and HR 0.90, 95% CI 0.87–0.93, p<0.001). There was no difference in the likelihood of receiving RC and CRT among different residential areas. Among patients who underwent RC; individuals living in URR were less likely to receive neoadjuvant chemotherapy and adequate lymph node dissection, and had a higher probability of positive surgical margin than those living in metro areas. For those who received CRT; individuals living in Metro areas were more likely to receive concomitant systemic therapy compared to URR. Conclusions: Rural residence is associated with lower OS for MIBC patients and less likelihood of meeting quality benchmarks for RC and CRT. This data should be used to guide further health policy and allocation of resources for rural population.

Experimental and Numerical Analyses of Buried HDPE Pipe with Using EPS Geofoam

Furkan A. Akyelken,Havvanur Kılıç 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.9

High density polyethylene (HDPE) pipes are generally not used in applications that will beexposed to high filling stresses. For this reason, there are not enough experimental andnumerical analysis studies in the literature on the reduction of stresses on HDPE pipes withsoft zone application. In this study, it was aimed to evaluate the performance of imperfecttrench installations containing soft material zone for buried HDPE pipe by numerical analysis. Laboratory-scale experiments and numerical analyses were conducted to study theperformance of the HDPE pipe with soft zone application. A surcharge load was applied tothe backfill, and earth pressure and soil settlements around the HDPE pipe and pipedeflections were measured for two soft zone geometries. After validation of the test results bya numerical method, parametric studies were performed to investigate the change of EPSGeofoam material and backfill soil type. According to the results, it was seen that thehorizontal and vertical stresses acting on the pipe decreased by 65% − 70% in accordancewith the experimental measurements. It has been determined that the deformations of pipesunder 10m filling load do not exceed 1%. Experimental and numerical results show that byapplying a soft zone around the HDPE pipe, the stresses acting on the side wall of the pipe aresignificantly reduced, and the behavior of the pipe is not affected much by the infill soil type.

Synthesis, structural characterization, and in vitro anti-cancer activities of new phenylacrylonitrile derivatives

Furkan Özen,Suat Tekin,Kenan Koran,Süleyman Sandal,Ahmet Orhan Görgülü 한국응용생명화학회 2016 Applied Biological Chemistry (Appl Biol Chem) Vol.59 No.2

The present study was designed to both synthesize phenylacrylonitrile compounds (1a–k) and their anti-tumor activities on human breast cancer cell line (MCF-7) were determined. The structures of all the compounds were defined by melting point, elemental analysis, FT-IR, 1H, 13C, 13C-APT, and HETCOR-NMR spectroscopy. Anti-tumor activities of these compounds on cell viability were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay against MCF-7. The MCF-7 cell lines were treated with 1, 5, 25, 50, and 100 μM concentrations of phenylacrylonitrile compounds for 24 h. At the end of the experiments, 1a, 1b, 1c, 1g, and 1h compounds reduced cell viability (p < 0.01). Additionally, the anti-cancer activities of these compounds on MCF-7 were investigated by comparing IC50 values. In conclusion, while some of the synthesized phenylacrylonitrile compounds (1a, 1b, 1c, 1g, and 1h) have anti-tumor activity, other phenylacrylonitrile compounds (1d, 1e, 1f, 1k, and 1h) have no effect on human breast cell lines.

Detection of Antibiotic Resistance and Resistance Genes in Enterococci Isolated from Sucuk, a Traditional Turkish Dry- Fermented Sausage

Furkan Demirgü,l,Yasin Tuncer 한국축산식품학회 2017 한국축산식품학회지 Vol.37 No.5

The aim of this study was to isolate enterococci in Sucuk, a traditional Turkish dry-fermented sausage and to analyze isolates for their biodiversity, antibiotic resistance patterns and the presence of some antibiotic resistance genes. A total of 60 enterococci strains were isolated from 20 sucuk samples manufactured without using a starter culture and they were identified as E. faecium (73.3%), E. faecalis (11.7%), E. hirae (8.3%), E. durans (3.3%), E. mundtii (1.7%) and E. thailandicus (1.7%). Most of the strains were found resistant to rifampin (51.67%) followed by ciprofloxacin (38.33%), nitrofurantoin (33.33%) and erythromycin (21.67%). All strains were found susceptible to ampicillin. Only E. faecium FYE4 and FYE60 strains displayed susceptibility to all antibiotics. Other strains showed different resistance patterns to antibiotics. E. faecalis was found more resistant to antibiotics than other species. Most of the strains (61.7%) displayed resistance from between two and eight antibiotics. The ermB, ermC, gyrA, tetM, tetL and vanA genes were detected in some strains. A lack of correlation between genotypic and phenotypic analysis for some strains was detected. The results of this study indicated that Sucuk manufactured without using a starter culture is a reservoir of multiple antibiotic resistant enterococci. Consequently, Sucuk is a potential reservoir for the transmission of antibiotic resistance genes from animals to humans.

Peripartum Cardiomyopathy, Hemolysis, Elevated Liver Enzymes, Low Platelet Values Syndrome, and an Incidental Atrial Septal Defect in a Multiparous Woman

Onur Furkan Akgün,Erhan Kılıç,Yavuzer Koza,Hakan Tas 아시아심장혈관영상의학회 2023 Cardiovascular Imaging Asia Vol.7 No.2

Peripartum cardiomyopathy (PPCM) and hemolysis, elevated liver enzymes, low platelet values (HELLP) syndrome are rare conditions with unknown etiologies and are associated with increased maternal and perinatal morbidity and mortality. However, survival chances can be increased and full recovery may be achieved in patients who receive an early diagnosis and treatment. We report the clinical follow-up of a multiparous woman who developed HELLP syndrome on the second day of the postpartum period and PPCM on the 40th day and was found to have an incidental secundum-type atrial septal defect.

Prediction of Magnetic Pollution with Artificial Neural Network in Living Areas

Sakacı Furkan Hasan,Cerezci Osman 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.5

The high voltage transmission and distribution lines are source of the extremely low frequencies (ELF) radiation. The increasing use of transmission of electrical energy is causing concerns regarding the risks of human exposure to ELF from the lines. In recent years studies investigating the interaction of ELF magnetic fi elds with human body have become important. Epidemiological studies report that magnetic fi elds emitted from power lines increase the incidence of leukemia in the children of people living near power lines. In the municipality of Nilufer with a population of 600,000 in Bursa province, which is one of the largest cities in Turkey, high voltage lines pass over residential areas or very close to houses and schools. Studies are being carried out to reduce electromagnetic pollution in this region. Within the scope of this study, magnetic fi eld measurement values arising from high voltage lines were taken between 2014 and 2019. In order to make sense of these values, fi rst of all analyzes were made by mapping. After the analysis, the data set was created by labeling. Using the data set created, magnetic measurement values were trained based on parameters in dataset. After the training, the predictions and actual results were compared by testing with the data not used during the training. In addition, by making 3D drawings according to the latitude and longitude of the region, places where electromagnetic pollution may be high were found and measures were taken for these places

Dynamic ultrasound examination of the median nerve during follow-up after wrist fracture/surgery

( Ahmet Furkan Çolak ),( Ayşe İrem Yeşiloğlu ),( Alpaslan Fatih Kaynar ),( Bayram Kaymak ),( Levent Özçakar ) 영남대학교 의과대학 2024 Yeungnam University Journal of Medicine Vol.41 No.1