THE EFFECT OF MEMBER GROUPING ON THE OPTIMUM DESIGN OF GRILLAGES VIA SEARCH TECHNIQUES

Member grouping of a steel grillage system has an important effect in the minimum weight design of these systems. In the present research, this effect is investigated using an optimum design algorithm which is based on two stochastic search techniques called particle swarm (PSO) and harmony search (HS) optimization methods. The optimum design problem of a grillage system is formulated by implementing LRFD-AISC (Load and Resistance Factor Design-American Institute of Steel Construction) limitations. It is decided that W-Sections are to be adapted for the longitudinal and transverse beams of the grillage system. 272 W-Section beams given in LRFD code are collected in a pool and the optimum design algorithm is expected to select the appropriate sections from this pool so that the weight of the grillage is the minimum correspondingly the design limitations implemented from the design code are satisfied. The solution for this discrete programming problem is determined by using the PSO and HS algorithms. Design example is presented to demonstrate the effect of beam spacing and performances of stochastic search techniques in the optimum design of grillage systems

Kitap Kritiği: Orta Doğu ve Kuzey Afrika Bölgesinde Gıda Bağımlılığı: 2050 Yılı Retrospektif Analiz Öngörüleri

This book, Food Dependency in the Middle East and North Africa Region: Retrospective Analysis Projections to 2050, sets out the risks to food security in the Middle East and North Africa (MENA) region from various issues, including climate change, and how these vulnerabilities interact with other key trends and sources of risk, including population growth, urbanisation, and conflict. Focused on the year 2050, this book contributes to a better understanding of how these trends and threats may affect the region in the coming years. The book predicts that the MENA region will continue to be one of the most import-dependent regions in the world. About half of the food in the region is imported; however, given high population growth rates, with a population growth of 1.7% in 2020 across the MENA region, the second fastest globally, behind only Sub-Saharan Africa. According to the findings of this analysis, import dependency is predicted to expand further by 2050. Some sub-regions are still struggling to attain sustainable levels; the MENA might import 60 to 70% of their food needs.This book, Food Dependency in the Middle East and North Africa Region: Retrospective Analysis Projections to 2050, sets out the risks to food security in the Middle East and North Africa (MENA) region from various issues, including climate change, and how these vulnerabilities interact with other key trends and sources of risk, including population growth, urbanisation, and conflict. Focused on the year 2050, this book contributes to a better understanding of how these trends and threats may affect the region in the coming years. The book predicts that the MENA region will continue to be one of the most import-dependent regions in the world. About half of the food in the region is imported; however, given high population growth rates, with a population growth of 1.7% in 2020 across the MENA region, the second fastest globally, behind only Sub-Saharan Africa. According to the findings of this analysis, import dependency is predicted to expand further by 2050. Some sub-regions are still struggling to attain sustainable levels; the MENA might import 60 to 70% of their food needs

Computer aided strength anaylses of weldments

Günümüzde en yaygın olarak kullanılan birleştirme yöntemlerinden biri olan kaynak işleminde malzemenin kaynak sonrası davranışlarını önceden tahmin edebilmek kaynaklı yapının mukavemeti ve çalışma verimi açısından oldukça önemlidir. Bu çalışmada, tozaltı kaynağı yöntemi kullanılarak kaynak edilmiş parçaların kaynak metali, ısının tesiri altında kalan bölge ve esas metal bölgelerinin mekanik özelliklerini düz çekme numuneleri kullanılarak belirlemek amacıyla deneysel bir araştırma yapılmıştır. Çekme deneylerinden elde edilen sonuçlar kullanılarak tozaltı kaynağı prosesinin sonlu eleman modeli oluşturulmuştur. Modellemede ANSYS sonlu eleman paket programı kullanılmıştır. Analiz iki aşamada gerçekleştirilmiştir. İlk olarak kaynak işleminde meydana gelen ısıl çevrimden hareketle termal analiz yapılmıştır. Termal analiz sonucunda elde edilen veriler mekanik analize girdi olarak ikinci aşamada kullanılmıştır. Modelleme ile kaynak sonrası malzemenin durumu önceden tahmin edilebildiği gibi kaynak parametrelerinin optimizasyonu da sağlanabilmektedir.In the welding process, which is one of the most widespreadly utilised joining process, to estimate the behaviours of the material after welding is very important for the strength and working productivity of weldments. In this study, an experimental investigation on the mechanical properties of submerged arc welded joints using flat tensile specimens was carried out to determine the tensile properties of the base metal, weld metal and heat-affected zone of weldments and a finite element model of the submerged arc wielding process was carried out using the results of the experiments. ANSYS finite element package program has been used in modelling Analysis has been made in two steps. Initially thermal analysis has been made by the thermal cycle that occurs in the welding process. Then the results those obtained from the thermal analysis have been used in the second step as inputs for the mechanical analysis. The situation of the material after welding can be estimated by modelling, also the optimisation of welding parameters can be done.ÇİMTAŞOYAK-RENAUL

The way from renewable energy sources to potential feed opportunities : Distillers grains : II Distillers grains in ruminant rations

Karbon temelli yakıtların tükenme riski insanoğlunu yeni enerji kaynakları arayışına yöneltmiştir. Bu arayışlar içerisinde tahıllardan fermantasyon yolu ile üretilen etanolün biyo-benzin olarak değerlendirilmesi ilgi çekmektedir. Bu işlem esnasında yan ürün olarak elde edilen damıtık tahıllar ise içerdiği yüksek rumende sindirilmeyen protein (RUP) ve mısıra eşit enerji düzeyi ile hayvan besleme açısından yeni ve değerli bir yem potansiyeli oluşturmaktadır.The possibility of using up all carbon based fuels has been urging mankind into finding new energy sources. This search has shown that ethanol, which is produced from grains via fermentation, has attracted interest as it is assessed to be bio‐ethanol. Distillers grains, obtained during production process, has potential as a new and valuable kind of feed for animal nutrition because, it includes high amount of rumen undegradable protein (RUP) and energy level which is equal to corn

The way from renewable energy sources to potential feed opportunities: distillers grains I- obtaining distiller grains and their properties

Akaryakıt olarak kullanılacak etanol, nişasta gibi şekere dönüştürülebilen veya şeker içeren her biyolojik kaynaktan üretilebilmektedir. Bunun yanı sıra, tarımsal atıklar ve odun atıkları ile hızlı büyüyen ağaçlar ve otlar gibi selülozca zengin malzemelerden de elde edilebilmektedir. Temelde iki çeşit yöntemle etanol üretimi söz konusudur. Bunlar, yaş ve kuru öğütme yöntemleridir. Özellikle kuru öğütme yöntemi ile etanol üretimi esnasında elde edilen ürünler, hayvan beslemede yeni ve değerli bir yem potansiyeli oluşturmaktadır.Ethanol to be used as fuel can be produced from each source that can be converted into sugar or from that of biological origin containing sugar. Besides, ethanol can be produced from cellulose-rich materials such as agricultural wastes, wood wastes, fast-growing trees and herbs. Basically, two types of ethanol production are used. These are wet and dry grinding methods. Especially those products obtained during dry grinding method have potential as a new and valuable kind of feed for animal nutrition

Optimum Design of Geodesic Steel Domes Under Code Provisions using Metaheuristic Techniques

Metaheuristic search techniques strongly employ randomized decisions while searching for solutions to structural optimization problems. These techniques play an increasingly important role for practically solving hard combinatorial problems from various domains. Over the past few years there has been considerable success in developing metaheuristic search algorithms as well as randomized systematic search methods for obtaining solutions to discrete programming problems. This paper examines minimum weight design of pinjointed geodesic steel domes using seven metaheuristic search techniques; namely, simulated annealing, genetic algorithms, evolution strategies, particle swarm optimizer, tabu search, ant colony optimization and harmony search methods. The optimum design problem of geodesic steel domes is formulated according to design limitations stipulated by ASD-AISC (Allowable Stress Design Code of American Institute of Steel Institution). The minimum design loads and combined load effects are established as specified by ASCE 7-98 (Minimum Design Loads for Buildings and Other Structures, American Society of Civil Engineers). A numerical example is presented, where seven metaheuristic methods are implemented to achieve minimum weight design of a 130member geodesic steel dome subjected to a total of eight combined load cases of dead, live, snow and temperature load

Adaptive Harmony Search Method for Structural Optimization

This paper presents an adaptive harmony search algorithm for solving structural optimization problems. The harmony memory considering rate and pitch adjusting rate are conceived as the two main parameters of the technique for generating new solution vectors. In the standard implementation of the technique appropriate constant values are assigned to these parameters following a sensitivity analysis for each problem considered. The success of the optimization process is directly related on a chosen parameter value set. The adaptive harmony search algorithm proposed here incorporates a new approach for adjusting these parameters automatically during the search for the most efficient optimization process. The efficiency of the proposed algorithm is numerically investigated using two large-scale steel frameworks that are designed for minimum weight according to the provisions of ASD-AISC specification. The solutions obtained are compared with those of the standard algorithm as well as of the other metaheuristic search techniques. It is shown that the proposed algorithm improves performance of the technique and it renders unnecessary the initial selection of the harmony search parameters

The Serological Screening of Wild Rodents for Hantavirus Infections in the Middle and Southern Anatolia Region of Turkey

Amaç: Hantavirüsler, enfekte kemirici ve bazı böcekçillere ait sekresyonlardaki viral partiküllerin solunması yolu ile insanlara bulaşmaktadır. Renal sendromlu kanamalı ateş (RSKA) etkeni olan Hantavirüs alt tiplerinden Dobrava (DOBV), Puumala (PUUV), Saaremaa (SAAV), Tula (TULV) ve Seoul (SEOV) virüslerin taşıyıcısı olarak bilinen kemirici türleri ülkemizde de yayılım göstermektedir. Hantavirüs enfeksiyonlarında grip benzeri bulguların görülmesi ve hastalığın hızla ilerlemesi, erken tanı konulmasını zorlaştırmaktadır. Bu nedenle saha çalışmaları ile alandaki Hantavirüs prevalansı belirlenmekte ve olası salgın bölgeleri öngörülerek, bölgedeki halk ve yetkili kişiler önceden uyarılabilmektedir. Bu araştırmada, saha araştırması ile bölge taraması yapılması amaçlanmıştır.Gereç ve Yöntem: Bu çalışma ile Muğla, Antalya, Niğde, Aksaray, Konya, Karaman, Mersin, Hatay illerinden yakalanan Apodemus spp., Microtus spp. ve Mus spp. türlerinden 193 kemiriciye ait serum örnekleri serolojik olarak tarandı. Bulgular: Bu kemiricilerde Hantavirüse özgül antikor varlığı saptanmadı. Sonuç: Türkiye'de Hantavirüs açısından taranmamış pek çok bölge bulunmaktadır. Yapılacak yeni çalışmalar ile diğer bölgelerde Hantavirüs prevalansının ve bölgelerin risk durumunun belirlenmesi önem taşımaktadırObjective: Hantaviruses infect humans via inhalation of the viral particles in the secretions of some rodents and insectivores. The rodent species which known as reservoirs of Dobrava (DOBV), Puumala (PUUV), Saaremaa (SAAV), Tula (TULV) and Seoul (SEOV) viruses of Hantavirus subtypes which cause hemorrhagic fever with renal syndrome (HFRS) are are also found in Turkey. Early diagnosis of Hantavirus infections is difficult, because of the flu-like symptoms and rapid progression of the disease. However, the prevalance of hantavirus seropositivity in rodents from the field works could predict and warn authorities for possible human outbreaks. In this study field research and regional screening were aimed.Material and Methods: In the present study serum samples of 193 rodents of Apodemus spp., Microtus spp. and Mus spp. collected from Muğla, Antalya, Niğde, Aksaray, Konya, Karaman, Mersin, Hatay Provinces were screened using serological methods.Results: The presence of antibody against Hantaviruses were not detected in these rodents.Conclusion: There are a large number of geographical areas in Turkey that have not screened for hantaviruses. Determination of Hantavirus prevalance and the risk status of other regions in further studies to be performed conveys importanc

Yapısal Optimizasyon Problemlerinin Çözümlerini Bulmak için Kullanılan Meta-Bulgusal Araştırma Yöntemlerinin Karşılaştırılması

Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2011Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2011Bu çalışmada, mühendislik literatüründen alınmış olan yapısal optimizasyon problemlerinin çözümünü bulmak için kullanılan üç farklı meta-bulgusal yöntemin performans değerlendirmesi yapılmıştır. Seçilen bu uç yöntem Partikül Küme. Harmoni Arama ve Genetik Algoritmalar yöntemleridir. Yapısal optimizasyon ıilıınında kullanılan meta-bulgusal araştırma yöntemleri araştırma alanında daha iyi sonuç bulmak için bulgulara güvenirler. Bu metotlar, optimum çözümü araştırırken belirleyici niceliklerden ziyade rastgele ve ulus ılıklı parametreler kullanırlar. Rastgele değişkenlerin kaynağı, problemin tipine ve doğasına bağlı olmak farklı olabilir. Bu yenilikçi tekniklerin gerisindeki bulgusal yöntemler doğadan ve fizikten ödünç alınmıştır. İki adet farklı geometri ve yapı konfîgürasyonuna sahip olan 46-elemanlı düzlemsel çelik kafes sistemi, bahsi geçen meta-bulgusal yöntemlerin bu tip yapısal optimizasyon problemlerinin çözümünde ne luiılar etkili olduklarını göstermek için tasarım örnekleri olarak seçilmişti