Use of trigonometric series functions in free vibration analysis of laminated composite beams

In this study, free vibration analysis of layered composite beams is performed by using an analytical method based on trigonometric series. Based on the first-order shear deformation beam theory, the governing equations are derived from the Lagrange’s equations. Appropriate trigonometric series functions are selected to satisfy the end conditions of the beam. Navier-type solution is used to obtain natural frequencies. Natural frequencies are calculated for different end conditions and lamina stacking. It was seen that the slenderness, E11/E22 and fiber angle have a significant effect on natural frequency. The results of the study are quite compatible with the literature

Elastik Zemine Oturan Sonsuz Uzun Elastik Kirişin Hareketli Yük Altında Dinamik Davranışı

Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2013Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2013Bu çalışmada, elastik zemine oturan sonsuz uzun kirişin hareketli yük altında dinamik davranışı incelenmiştir. Hareket denkleminin analitik çözümü için üstel Fourier dönüşümü kullanılmıştır. Ters dönüşümlerde ortaya çıkan integrallerin hesabı rezidü integral teoremi ile yapılmış ve kirişin dinamik yer değiştirmelerinin yük hızı, yatak katsayısı ve sönüme göre değişimi incelenmiştir. Anahtar Kelimeler: Hareketli Yük, Rezidü Teoremi, Fourier Dönüşümü, Sonsuz Kiriş, Elastik ZeminIn this study, dynamic behavior of an infinite elastic beam on elastic foundation under moving load is investigated. The complex Fourier transform and the residue integral theorem are used in the analytical solution. Variation of dynamic displacements of the beam under moving loads is investigated with the load speed, the foundation stiffness, the beam damping. Keywords: Moving Load, Residue Theorem, Fourier Transform, Infinite Beam, Elastic Foundatio

Hareketli Yük Altında Köprü Titreşimlerinin Ayarlı Kütle Sönümleyiciler Kullanılarak Azaltılması

Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2013Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2013Bu çalışmada, ayarlı kütle sönümleyiciler (AKS) kullanılarak hareketli yük etkisindeki tek açıklıklı köprülerde meydana gelen titreşimlerin azaltılması problemi ele alınmıştır. Problemin çözümü analitik ve sayısal olarak iki farklı yoldan yapılmıştır. AKS kullanımının köprünün dinamik davranışı üzerindeki etkileri incelenmiştir. Sayısal sonuçlar, AKS kullanımının köprülerde titreşimin azaltılmasında önemli bir etkiye sahip olduğunu göstermiştir. Anahtar Kelimeler: Hareketli yük, Ayarlı kütle sönümleyici, Köprü, Titreşim azaltmaIn this paper, the problem of vibration reduction of single span bridges under moving loads using tuned mass dampers (TMDs) is considered. Solution of the problem is obtained by using both analytical and numerical methods. Effect of the use of TMDs on the dynamic behavior of bridges are examined. Numerical results show that the use of TMDs has a great effect on suppression of the bridge vibrations. Keywords: Moving load, Tuned mass damper, Bridge, Vibration suppressio

Tabakalı Elastik Ortamların Dönel Simetrik Yükleme Altında Statik Analizi

Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2015Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2015Bu çalışmada, dönel simetrik yükleme altında tabakalı elastik ortamın statik analizi rijitlik matrisi metodu ile incelenmiştir. Tabakalarda meydana gelen yer değiştirme ve gerilmeler elde edilerek elastisite ve sonlu eleman çözümleriyle karşılaştırılmıştır. Anahtar Kelimeler: Tabakalı elastik ortam, Dönel simetrik yükleme, Rijitlik matrisi metodu, Sonlu elemanlar metoduIn this study, static analysis for elastic layered media under axisymmetric loading are investigated by the stiffness matrix method. Displacements and stresses occurring in the layer are obtained and compared with elasticity and finite element solutions Keywords: Multilayered elastic media, Axisymmetric loading, Stiffness matrix method, Finite element metho

Częstość występowania rozejścia mięśni prostych brzucha w populacji młodych wieloródek w Turcji

Objectives: To determine the prevalence and factors associated with diastasis recti abdominis (DRA). Material and Methods: Between January 2011 and May 2011, we examined 95 patients, aged between 19-24, for the presence of DRA during an ultrasonographic exploration in Mus Obstetrics and Gynecology Hospital, Mus, Turkey. DRA was graded by the number of fingerbreadths between the medial edges of the bellies of the rectus abdominis muscle, 3-4 cm above the umbilicus. The exclusion criteria included urogynecologic problems since childhood, excessive protrusion of the vagina due to loss of support, pregnancy, obesity, less than 6 months postpartum. The relationship between DRA and parity, previous abdominal surgery, pelvic relaxation as well as type of parity was assessed. Results: Positive correlation was found between parity and DRA (r=0.77; pStreszczenie Cel pracy: Ocena częstości występowania i czynników ryzyka rozejścia mięśni prostych brzucha (DRA). Materiał i metody: W okresie od stycznia 2011 do maja 2011 zbadano 95 pacjentek, w wieku 19-24 lat, pod kątem obecności DRA przy pomocy ultrasonografii w Szpitalu Ginekologiczno-Położniczym w Mus w Turcji. DRA klasyfikowano na podstawie liczby palców pomiędzy brzegami mięśnia prostego brzucha, 3-4cm powyżej pępka. Kryteria wykluczenia stanowiły schorzenia uroginekologiczne w dzieciństwie, wypadanie pochwy w związku z utratą podpory, ciążą, otyłością oraz okres do 6 miesięcy od porodu. Oceniano związek pomiędzy DRA a rodnością, rodzajem porodów, poprzednimi operacjami brzusznymi oraz rozluźnieniem miednicy. Wyniki: Znaleziono związek pomiędzy rodnością a DRA (r=0,77;

Całkowita histerektomia laparoskopowa metodą pojedynczego nacięcia pępkowego: technika i pierwsze doświadczenia w Turcji

Objectives: The aim of the study is to determine the results of our initial experience of 32 cases who underwent single incision total laparoscopic hysterectomy. Materials and Methods: Thirty-two patients who underwent transumbilical single incision total laparoscopic hysterectomy between March 2009 and February 2011 were reviewed retrospectively at the Department of Obstetrics and Gynecology, Ege University Faculty of Medicine, Izmir, Turkey. Articulating and rigid instruments, 30 degrees 10 mm telescope, SILS™ port and advanced bipolar and mechanical energy modalities were used during the procedure. Duration of surgery, length of hospital stay, mean blood loss and postoperative complications were assessed. Results: Mean age of patients and mean operation time were 48 years (ranged 42-55) and 108 minutes (ranged 80-180), respectively. In all cases vaginal cuff s were closed with either intracorporeal or extracorporeal separate sutures. There were no intraoperative complications. All patients were discharged within 48 hours postoperatively. The mean length of hospital stay and mean blood loss were as 1.6 days (range 1-2) and 45 ml (range 30-100), respectively. Conclusions: Total laparoscopic hysterectomy performed through transumbilical single incision is technically feasible and safe. Development of advanced fl exible instrumentation and visualization platform may facilitate this new operative approach.Cel pracy: Celem tego badania była ocena wyników naszego pierwszego doświadczenia z 32 pacjentkami, które przeszły całkowitą laparoskopową histerektomię metodą pojedynczego nacięcia. Materiał i metoda: Przeanalizowano retrospektywnie trzydzieści dwie pacjentki, które przeszły całkowitą laparoskopową histerektomię metodą pojedynczego nacięcia pępkowego pomiędzy marcem 2009 a lutym 2011, w Oddziale Położniczo-Ginekologicznym, Ege University Faculty of Medicine w Turcji. W trakcie procedury użyto instrumentarium giętkiego i sztywnego, endoskopu o kącie widzenie 30°, 10mm, portu SILSTM i zaawansowanych urządzeń bipolarnych oraz energii mechanicznej. Oceniono czas trwania operacji, długość pobytu w szpitalu, średnią utratę krwi i komplikacje pooperacyjne. Wyniki: Średnia wieku pacjentek wynosiła 48 lat (zakres 42-55), średni czas trwania operacji 108 minut (zakres 80-180). We wszystkich przypadkach mankiet pochwy zeszyto osobnymi szwami wewnątrzbrzusznymi lub zewnątrzbrzusznymi. Nie obserwowano żadnych powikłań w trakcie operacji. Wszystkie pacjentki wypisano do domu w ciągu 48 godzin od operacji. Średni czas pobytu w szpitalu wynosił 1,6 dni (zakres 1-2) a utrata krwi wynosiła 45ml (zakres 30-100). Wnioski: Całkowita laparoskopowa histerektomia metodą pojedynczego nacięcia pępkowego jest technicznie wykonalna i bezpieczna. Ulepszanie zaawansowanego, elastycznego instrumentarium oraz możliwości wizualizacji ułatwiają to nowe podejście operacyjne

Towards harmonizing property measurement standards

Area and volume values of buildings and building parts have been used in many applications including taxation, valuation and land use planning. Many countries maintain a national standard for representing the measurements of floor areas in buildings. The national standards generally use similar basis for measuring building floor areas, in fact, areas specified in national standards often have semantic differences. Therefore, a number of international standards have been developed for harmonizing floor area measurements; however, they also have differences. This study aims at harmonizing the floor areas defined in the international property measurement standards by revealing the semantic relations between them and formalizing them with an ontological approach. To achieve this objective, the international property measurement standards were firstly examined in order to identify semantics, principles and practices in floor area measurements. Then, the obtained information were utilized to develop a set of measurement ontologies for harmonizing the property measurement standards. This paper also investigates 3D data standards to reveal whether they can be utilized for realizing the property measurement standards

Safety culture assessment and implementation framework to enhance maritime safety

Accident investigation reports attribute the majority of marine accidents to human and organizational factors. Significant efforts are made to eliminate these errors in the maritime industry, but after each catastrophic accident, the maritime industry adopts a reactive approach which results in new regulations and an excessive amount of paperwork. None of these efforts provide the desired safety level for the maritime industry. Currently, the maritime industry is starting to implement proactive approaches and has tried to avoid re-occurrences by implementing an appropriate safety culture. Safety culture is defined as “how an organization behaves when no one is watching”. The safety culture approach describes humans as a means for improving safety rather than someone to blame for failure. A positive safety culture with commitment from all levels in the company can achieve the envisaged and required safety levels in the maritime industry. This paper presents a novel safety culture assessment and improvement framework to enhance the maritime safety and introduces preliminary results of the safety climate assessment within a company. The proposed framework will collect seafarer's attitudes, leading/lagging indicators and key performance indicators to analyze a company's current safety culture level and address the weakest areas to enhance the level of safety accordingly. New strategies and action plans will be proposed to improve these vulnerable areas. The selection of safety indicators will be adjustable according to a company's specific needs and the available data types. Safety indicators have a crucial importance in gaining an insight into a company's safety performance. The safety culture improvement framework will provide a guided way for companies to perform gap identification on their safety level. A management tool will also be developed for shipping companies to analyze and observe their current safety culture level continuously. Implementation of the safety culture assessment framework is a long term process and it requires up to five years of continual effort to get the final results. The results section doesn’t go beyond the assessment of safety climate and identification of the main differences between shore staff and crew members. In the next stages of the study, interviews and observations will be performed to validate the results of the questionnaire. More structured means of statistical analysis will be conducted to identify correlations between safety performance data and safety metrics

Glutaraldehidin kazara epidural uygulanmasının ağır komplikasyonu

Epidural anestezi altında sol femoropopliteal bypass uygulanan hastaya ameliyat sonrası altıncı saatte epidural kateter yoluyla kazara 3 ml %3 glutaraldehid solüsyonu uygulandı. Glutaraldehid uygulamasını takiben hastada hipotansiyon, taşikardi, bulantı ve kusma gibi sistemik semptomlara ek olarak parapleji gelişti. Bir yıllık medikal tedavi ve rehabilitasyon programı sonunda nörolojik semptomlarda iyileşme olmadı.In a patient operated for left femoropopliteal bypass under epidural anesthesia, 3 ml of 3% glutaraldehyde solution was administered through the epidural catheter at the postoperative sixth hour accidentally. Following glutaraldehyde administration, the patient developed paraplegia in addition to systemic symptoms such as hypotension, tachycardia, nausea and vomiting. At the end of the first year, neurologic symptoms didn't improve despite medical treatment and rehabilitation program

SEAHORSE procedure improvement system

Standardisation of operating procedures has been used in variety of different sectors with the aim of achieving more reliable operations hence operational safety. Likewise, Standard Operating Procedures (SOPs) have been adopted by the maritime sector and enforced through the regulatory framework in an attempt to achieve safer shipping operations. Despite the fact that regulations enforce the SOPs, it is often observed that during shipping operations these procedures are not followed due to various reasons. One of the most common reasons for not following the SOPs is because shipping companies suffer from poorly designed procedures, which are impractical, unclear or sometimes factually wrong. These poorly designed procedures are disregarded by crew members, which prevent the practical implementation of these SOP's during shipping operations. Therefore, it is of key importance that a systematic approach is needed to identify and improve the current SOP's as well as preventing potentially harmful workarounds. The EU FP7 SEAHORSE project is developing a "Procedure Improvement System" which will be actively used by the crew members any time anonymously. In order to achieve this, over 400 questionnaires have been collected from seafarers across Europe where they were asked to report on impractical SOPs and common workarounds conducted on board ships. These questionnaires were organised and a risk benefit analysis was conducted. This paper will report the initial results, as well as demonstrating the overall methodology for the SEAHORSE Project's procedure improvement system