307 research outputs found
Bir Yolcu Uçağı Koltuğunun Dinamik Düşürme Analizi
Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2013Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2013Uçak yolcularını tehlikeli iniş durumlarından veya kazalardan korumak amacıyla ABD Federal Havacılık Kurulu'nun (FAA) yayınlamış olduğu bazı standartlar ve kurallar bulunmaktadır. Bu standartların dışında FAA sıklıkla bu kurallara temel oluşturması bakımından bazı testler ve simülasyonlar da gerçekleştirmektedir. Uçak yolcu koltukları için yapılan düşürme testleri de bu düşünceyle incelenmektedir. Bu çalışma kapsamında, uçak yolcu koltuğunun mukavemeti incelenmiş ve yolcu güvenliği FAA'nın gerçekleştirmiş olduğu testlere ve koşullara dayanılarak doğrulamaları yapılmıştır. Bu koşullar, koltuk ve yolcunun 1 ve 2 metreden serbest düşmeye bırakılarak gerçekleştirilmiş testlerdir. Bunların yanında, yolcu güvenliğinin daha üst seviyelere çıkabileceği modern ekonomik bir uçak koltuğu tasarlamaya yönelik çalışmalar yapılmıştır. Tüm bu senaryoların benzeşimini yapmak için, bir sonlu elemanlar programı olan LS-DYNA kullanılmıştır. Yolcu modeli olarak ise, 50th percentile Hybrid III Anthropomorphic Test Dummy (ATD) seçilmiştir.Yine bu çalışma kapsamında, koltuklarda bulunan sünger tabakasının yolcu güvenliğine olan etkisi de incelenmiştir. Yolcu güvenliği ile ilintili olarak belli başlı önemli göstergeler bulunmaktadır. Bel bölgesine gelen kuvvetler ve baş yaralanma kriteri (HIC) bu göstergelerden en önemlileridir. Bu çalışma içerisinde yolcunun leğen kemiğine ve göğsüne gelen ivmelerin yanı sıra HIC değeri ve bel bölgesine gelen kuvvetler sunulmuş, koltuğun dayanımı incelenmiştir.The Federal Aviation Administration (FAA) has standards and regulations so as to protect aircraft passengers against some dangerous landing or crash. Further than these regulations, the FAA performs some tests and simulations in order to provide the basis for them. Aircraft seat drop test is examined in this point of view. In this study, the aircraft passenger seat strength and occupant safety are carried out on the basis of the conditions of the FAA conducted tests and verifications. In these tests, occupants and seat fall freely 1 and 2 meters. To extend the investigation, this paper aims the modern economical seat configurations with the higher passenger safety. Hence, a finite element explicit code, LS - DYNA, is used in order to simulate the scenarios. 50th percentile Hybrid III Anthropomorphic Test Dummy (ATD) was chosen to represent a human body. This paper also investigates the seat cushion layer effects on occupants safety. As related to passenger safety, Head Injury Criterion (HIC) is significant signs. Furthermore, forces to act in lumbar and then acceleration to act in pelvis and torso of ATD are shown in this paper. Some representations about the material strength of seat are included as solutions
A computed tomography-based morphometric study of the styloid process
Background: The styloid process (SP) refers to a cylindrical piece projecting from the inferior of the temporal bone, situated anterior to the stylomastoid foramen. It is an anatomic formation close to major vessels and nerves, and its excessive elongation results in pathologies leading to anatomical disorders, such as Eagle’s syndrome. Several studies have been conducted on SP in relation to its close proximity to vessels and nerves, but there is no study that reveals its distance to important anatomical formations, such as the internal auditory meatus (IAM), carotid canal (CC), cochlea, tegmen tympani (TT) and tragus. In the current study, we aimed to investigate the incidence of Eagle’s syndrome based on morphometric measurements of SP.
Materials and methods: The patient files archived in the Radiology Department of Adiyaman University Training and Research Hospital were retrospectively examined. The study was carried out on the data of patients for whom specialist radiologists found no pathology findings on the computed tomography images. A total of 77 individuals (36 females and 41 males) aged 22 to 54 years were included in the study. The length of SP and its distances to IAM, cochlea, CC, TT and tragus were obtained using computed tomography radiological measurements.
Results: When the individual measurements performed on computed tomography images were evaluated in men and women, no significant difference was found concerning the distance between SP and various anatomic structures in close proximity to SP (p > 0.05). However, there was a statistically significant difference between the genders in length of the right SP (p = 0.003) and left SP (p = 0.006).
Conclusions: This anthropometric study revealed the standard morphometric measurements of SP. We believe that the data obtained will help clinicians to identify and diagnose pathologies more easily
Pyramiding multiple genes for resistance to PVY, TSWV and PMMoV in pepper using molecular markers
Pepper (Capsicum annuum L.) is one of the most important vegetables cultivated worldwide. Many pests and pathogens cause economic yield losses in pepper. Potato virus Y (PVY), Tomato spotted wilt virus (TSWV) and Pepper mild mottle virus (PMMoV) are considered among the most destructive viruses affecting pepper in the world. Because chemical treatments have limited success for managing PVY, TSWV and PMMoV, resistant varieties are considered to be the most effective means of controlling these viruses. In this study, resistance genes to these viruses were successfully transferred to the superior sweet Charleston pepper line 'Y-CAR' using molecular markers and biological assays. As a result, a new line which is resistant to PVY, TSWV and PMMoV was developed. The results also showed the applicability of a pyramiding strategy for breeding multiple virus resistance in pepper. © Verlag Eugen Ulmer KG, Stuttgart.Scientific and Technological Research Council of Turkey, TEYDEP foundation (3080171
500 KW Rüzgar Türbini İçin Ana Şaft Tasarımı Ve Analizi
Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2013Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2013Bu çalışmada, 500 kW güç üreten bir rüzgar türbinin ana şaftının tasarımı ve yapısal analizleri yapılmıştır. Ana şaftın boyutlandırılmasında yorulma kriterlerinin esas alınması gerekmektedir. Ana şaftın yorulmaya ait yük durumu ise literatürde bulunan ampirik formüller kullanılarak hesaplanmıştır. Yorulma analizlerinde şaftı çevrimsel yüklerle zorlayan rotor ağırlığının yanında rüzgar kesmesi ve kule blokaj etkisi vb. sebeplerle ortaya çıkan değişken eğilme momenti ve tork değerleri de hesaba katılmıştır. Ana şaftın kritik kesitlerindeki çap hesabı, ASME Eliptik yorulma kriteri kullanılarak sonsuz ömre göre yapılmıştır. Ana şaftın tasarımındaki kritik bölgeler şaftın yataklandığı bölge ve şaftın dişli kutusuna bağlandığı bölgedir. Ayrıca, kontrol amaçlı olarak Uluslararası Elektroteknik Komisyonu’nun (International Electrotechnical Commision) yayınlamış olduğu IEC 64100-1 standardında belirtilen yükleme şartları için ana şaftın statik analizleri ANSYS 14.5 sonlu elemanlar yazılımı kullanılarak gerçekleştirilmiştir. Şaftın sonlu eleman modeli SOLID185 elemanlar kullanılarak oluşturulmuştur. Ayrıca, ana şaft - göbek bağlantı elemanlarının analizi de bu çalışma kapsamında yapılmıştır. Sayısal ve analitik yöntemler kullanılarak elde edilen deformasyon ve gerilme sonuçları karşılaştırılmış ve iyi bir uyum olduğu görülmüştür.In this paper, the main shaft which is one of the important structural parts for a 500 kW wind turbine has been designed. The fatigue criteria has been based on sizing the main shaft. The main shafts critic desing loads have been calculated by empirical formulas which are on the literatures. Oscillation moments of the torque and the flexural moments which is created by wind share, and effect of tower, etc. have been envisaged for analytical and numerical studies. In this study, the main shaft has been designed for infinite life using with ASME Elliptic criteria. There are two critic areas which are supported and connected to the gear box. In addition Iternational Electrotechnical Commision (IEC) 64100-1 standards have been based on the critic design load cases. The main shaft and the fasteners are modeled using the finite element method. The finite element model of the shaft is designed using with SOLID185 elements. Its static analysis have been achieved with using ANSYS 14.5 software. Also a comparison of two different approximations have been mentioned in this paper. The values of analitic and numerical of deplacement and stress are compared each
Antifungal screening and in silico mechanistic studies of an in-house azole library
Systemic Candida infections pose a serious public health problem with high morbidity and mortality. C. albicans is the major pathogen identified in candidiasis, however non-albicans Candida spp. with antifungal resistance are now more prevalent. Azoles are first-choice antifungal drugs for candidiasis, however they are ineffective for certain infections caused by the resistant strains. Azoles block ergosterol synthesis by inhibiting fungal CYP51, which leads to disruption of fungal membrane permeability. In this study, we screened for antifungal activity of an in-house azole library of 65 compounds to identify hit matter followed by a molecular modelling study for their CYP51 inhibition mechanism. Antifungal susceptibility tests against standard Candida spp. including C. albicans revealed derivatives 12 and 13 as highly active. Furthermore, they showed potent antibiofilm activity as well as neglectable cytotoxicity in a mouse fibroblast assay. According to molecular docking studies 12 and 13 have the necessary binding characteristics for effective inhibition of CYP51. Finally, molecular dynamics (MD) simulations of the C. albicans CYP51 (CACYP51) homology model's catalytic site complexed with 13 was stable demonstrating excellent binding. This article is protected by copyright. All rights reserved
Turner syndrome and associated problems in turkish children: A multicenter study
Objective: Turner syndrome (TS) is a chromosomal disorder caused by complete or partial X chromosome monosomy that manifests various clinical features depending on the karyotype and on the genetic background of affected girls. This study aimed to systematically investigate the key clinical features of TS in relationship to karyotype in a large pediatric Turkish patient population. Methods: Our retrospective study included 842 karyotype-proven TS patients aged 0-18 years who were evaluated in 35 different centers in Turkey in the years 2013-2014. Results: The most common karyotype was 45,X (50.7%), followed by 45,X/46,XX (10.8%), 46,X,i(Xq) (10.1%) and 45,X/46,X,i(Xq) (9.5%). Mean age at diagnosis was 10.2±4.4 years. The most common presenting complaints were short stature and delayed puberty. Among patients diagnosed before age one year, the ratio of karyotype 45,X was significantly higher than that of other karyotype groups. Cardiac defects (bicuspid aortic valve, coarctation of the aorta and aortic stenosi) were the most common congenital anomalies, occurring in 25% of the TS cases. This was followed by urinary system anomalies (horseshoe kidney, double collector duct system and renal rotation) detected in 16.3%. Hashimoto’s thyroiditis was found in 11.1% of patients, gastrointestinal abnormalities in 8.9%, ear nose and throat problems in 22.6%, dermatologic problems in 21.8% and osteoporosis in 15.3%. Learning difficulties and/or psychosocial problems were encountered in 39.1%. Insulin resistance and impaired fasting glucose were detected in 3.4% and 2.2%, respectively. Dyslipidemia prevalence was 11.4%. Conclusion: This comprehensive study systematically evaluated the largest group of karyotype-proven TS girls to date. The karyotype distribution, congenital anomaly and comorbidity profile closely parallel that from other countries and support the need for close medical surveillance of these complex patients throughout their lifespan. © Journal of Clinical Research in Pediatric Endocrinology
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