An extrusion simulation of an aluminum profile by porthole die

The aluminum alloys are ideal material because of their corrosion resistance, recycling ability, high specific strength and especially low density for lightweight structures of transportation, aerospace, automotive industries. Hot extrusion process is the most used metal forming method for obtaining a variety of aluminum alloy profiles. The demand for large cross section, multi cavity and thin wall profiles has been increasing with the development of the industry and extrusion method is key solution for producing complex profiles with high productivity. These profiles are generally extruded by porthole dies. The extrusion process by porthole die is complicated and die design has great importance for the quality of the extruded product. Design of the porthole die should give optimum material flow and homogenous temperature distribution both for obtaining desired profile and eliminating die scrap. The measuring the temperature and material flow is not possible for closed die formation and it is so important to estimate both material flow, temperature change in the die. For this aim, an extrusion simulation of a porthole die for standard aluminum profile was investigated in this study with the support of HyperXtrude Inspire Extrude Metal 2019 software, which is specialized for FEM calculations of extrusion process. Each step of extrusion process was simulated. Aluminum AA6063 material was used for simulations, the process temperature was 4500 °C and punch velocity was selected as 5 mm/sec. Finally, the FEM results were obtained and the temperature distribution, pressure distribution, billet interface and relative die exit speed results were analyzed

An Optimization Study for Bridge Design of a Porthole Extrusion Die

In this study, a porthole die extrusion simulation was carried out for a box profile by using HyperXtrude Inspire Extrude Metal 2019 which is a FEM based software. Aluminum AA6063 material was the billet material, tempera¬ture of the billet was 450 °C and ram speed was selected as 5 mm/sec. The die design was obtained according to the shape of the bridges of the porthole die. Finally, the design optimization was achieved by analyzing FEM results. It was obtained that the dies which have curved bridges offer optimum process conditions

Can Radiologist And Pathologist Reach The Truth Together In The Diagnosis Of Benign Fibroepithelial Lesions?

Objective Benign fibroepithelial lesions (BFL) lesions of the breast are various and predominantly benign, although a few can be locally aggressive. Definitive diagnosis of some BFL can be challenging from core needle biopsy (CNB). Radiological findings can help guide the management of the lesions. The aim of this study was to investigate the accuracy rate of CNB results and evaluate the radiological findings of the most common BFL according to the final excision pathology results. The secondary aim was to assess the contribution of the imaging findings to CNB results. Materials and Methods A retrospective review was made of 266 patients diagnosed with suspicious BFL, conventional fibroadenoma, complex fibroadenoma, cellular fibroadenoma and benign phyllodes tumor (PT). The study included 132 patients who underwent surgical excision. The radiological and histopathological findings were evaluated. Results While 66 patients were diagnosed with more descriptive results on CNB, the other 66 patients were diagnosed with suspicious BFL. Agreement between CNB and excisional pathology was good, when CNB provided a definite diagnosis. While conventional and complex fibroadenoma were observed to have hypo or normal vascularity, cellular fibroadenoma and PT showed hypervascularity. Oval shaped and homogeneous internal echo pattern were significantly associated with conventional fibroadenoma. A heterogeneous internal echo pattern was seen in complex fibroadenomas and PT. Conclusion CNB often reaches the correct diagnosis alone when it gives a definite diagnosis. The radiological findings which help in the differentiation of BFL are hypervascularity, oval shape and internal heterogeneity. More accurate results can be obtained when histopathological and radiological findings are evaluated together.PubMedWo

Electromyography in Pediatric Population, A Single Center Experience

Objective: Electromyography (EMG) is an electrophysiological diagnostic tool which sometimes is a challenge to perform evaluate in children. It plays an important role in the diagnosis of neuromuscular diseases together with neurological examination. We aimed to retrospectively evaluate the data of pediatric patients who applied to the EMG laboratory(for electrophysiological evaluation. Methods:Electrodiagnostic records of children aged 0-18 years, who were examined Dokuz Eylul University of Medicine Pediatric Neurology EMG laboratory between 2010-2021, were analyzed retrospectively. Abnormal results were subdivided according to localization in the lower motor unit pathway (anterior motor horn, root, plexus, peripheral nerve, neuromuscular junction, and muscle). The final diagnoses during the follow-up period and the laboratory and imaging findings were obtained from the electronical archive records. Results:Of the 995 patients enrolled, 48,4% (n=482) female, 51,5% (n: 512) were male. The most common presenting symptom was motor symptoms. Other reasons for application are shown in Chart-1. Patients who underwent EMG were most frequently referred from the Pediatric Neurology outpatient clinic followed by Pediatric Endocrine, Pediatric Hematology and Oncology, emergency service, and Pediatric Metabolism departments. 67.7% (n: 674) of the EMG recordings were normal. While the number of results consistent with neuropathy was 222 (22%), muscular, neuromuscular junction and plexopathy were observed in 4.9% (n: 49), 1.4% (n=14), and 3.2% (n: 32), respectively. Conclusion: Since electromyography is an important diagnostic tool in the evaluation of lower motor unit diseases, education for this particular technique in pediatric neurology clinics should be expanded.Keywords:&nbsp;electromyography, neuromuscular diseases, childhood</p

Imaging Findings And Clinicopathological Correlation Of Breast Cancer In Women Under 40 Years Old

Objective The aim of this study was to evaluate the clinical, imaging and histopathological features of breast cancer in patients aged under 40 years of age. The relationship between radiological characteristics and histopathological features was also investigated. Materials and Methods The study included 131 patients aged under 40 years, diagnosed pathologically with breast cancer. A retrospective evaluation was made of the imaging and clinicopathological findings and the relationship between pathological and imaging findings was investigated. Results Most of the cancers were detected from clinical symptoms, especially a palpable mass (76.3%). The most common histological type of tumor was invasive ductal carcinoma and 64.8% of the tumors were high grade tumors. The predominant features were irregular borders (92.4%), microlobulated-angulated contours (43.5%), hypo-homogeneous internal echogenicity (80.9%) on ultrasonography, and the presence of a mass (41.2%) and suspicious microcalcifications (40.2%) on mammography. Magnetic resonance imaging commonly showed mass enhancement (66.7%) with type 2 or 3 dynamic curve (92.6%). High-grade tumors were associated with posterior acoustic enhancement (p: 0.03) while low-grade tumors presented with spiculated margins more than high grade tumors (p: 0.04). Conclusion Breast cancer in women aged under 40 years usually presents with a self-detected palpable mass and can show different imaging findings according to the histological grade. Ultrasonography is the main modality for the diagnosis of breast cancer in young women, but mammography and magnetic resonance imaging can help in both diagnosis and evaluation of the extent of disease.PubMedWo

Evaluation of the Pediatric Neurology Consultations Requested from the Pediatric Emergency Service: A Single-Center Experience

Objective: Pediatric neurology opinion is one of the most frequently requested consultations in emergency service practice. Symptoms and/or signs such as headache, altered consciousness, seizures, and focal neurological deficits are the most common consultation reasons. We aimed to retrospectively evaluate patients who were consulted with the pediatric neurology department in the pediatric emergency service. Method: This is a descriptive cross-sectional study in which the consultation notes of patients who presented to the pediatric emergency service and required a consultation with the pediatric neurology department between June 2016 and November 2019 were analyzed retrospectively. Results: The number of the consulted patients was 1,265. Sixteen patients left the hospital after their parents signed treatment and examination rejection form, 1,249 consultations were included. The most common reasons for consultation were seizure, routine follow-up of patients that receive home mechanical ventilator support, and headache. The rate of emergency neurological pathologies detected in brain computed tomography and magnetic resonance imaging was 1.7%. The most common electroencephalographic abnormality was focal epileptic discharges. Consultation rate requiring emergent intervention was 14.8% and status epilepticus, central nervous system infections, intracranial masses were the most common causes. Conclusion: The most common reason for consultation was seizure. The rate of consultations requiring acute intervention was low. We think that the emergency service admissions of patients that need examination and treatment in the outpatient clinic may harm the routine functioning of the emergency service. Community education for the use of the emergency room only when necessary is essential

Publications of METU Faculty of Architecture / ODTÜ Mimarlık Fakültesi Yayınları - 2015

Publisher's Versio