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THE USE OF PHYSICAL MODELING FOR UNDERSEA MINING DESIGN

BICER, N

Conference Object | 1994 | MINE PLANNING AND EQUIPMENT SELECTION 1994 , pp.757 - 764

3rd International Symposium on Mine Planning and Equipment Selection -- OCT 18-20, 1994 -- ISTANBUL, TURKEY WOS: A1994BB59Q00124

The Importance of Chert in Central Anatolia: Lessons from the Neolithic Assemblage at Çatalhöyük, Turkey

Nazaroff A.J. | Baysal A. | Çiftçi Y.

Article | 2013 | Geoarchaeology28 ( 4 ) , pp.340 - 362

This paper is a presentation of three sources of artifact-quality chert in Central Anatolia. A previous dearth of research focused on locating and characterizing such raw material sources has incorrectly colored our view of prehistoric economic practices. To remedy this situation, we have conducted a survey of various locales within Central Anatolia to test for the presence of artifact-quality materials. We make use of Individual Attribute Analysis (IAA) and Energy Dispersive X-ray Fluorescence (EDXRF) analysis to discriminate among these materials, and suggest their use by the Neolithic occupants of Çatalhöyük through similar analy . . .ses of artifactual materials. We argue that the presence and characterization of these new sources allows us to better understand the intricacies of Neolithic practices by illustrating the ways in which the consumption of these materials was variably entwined with the exploitation of other resources, as well as embedded within social relations outside of Central Anatolia. © 2013 Wiley Periodicals, Inc. Daha fazlası Daha az

Optimization of design and operating parameters in a pilot scale Jameson cell for slime coal cleaning

Hacifazlioglu H. | Toroglu I.

Article | 2007 | Fuel Processing Technology88 ( 7 ) , pp.731 - 736

The Jameson flotation cell has been commonly used to treat a variety of ores (lead, zinc, copper etc.), coal and industrial minerals at commercial scale since 1989. It is especially known to be highly efficient at fine and ultrafine coal recovery. However, although the Jameson cell has quite a simple structure, it may be largely inefficient if the design and operating parameters chosen are not appropriate. In this study, the design and operating parameters of a pilot scale Jameson cell were optimized to obtain a desired metallurgical performance in the slime coal flotation. The optimized design parameters are the nozzle type, the he . . .ight of the nozzle above the pulp level, the downcomer diameter and the immersion depth of the downcomer. Among the operating parameters optimized are the collector dosage, the frother dosage, the percentage of solids and the froth height. In the optimum conditions, a clean coal with an ash content of 14.90% was obtained from the sample slime having 45.30% ash with a combustible recovery of 74.20%. In addition, a new type nozzle was developed for the Jameson cell, which led to an increase of about 9% in the combustible recovery value. Crown Copyright © 2007 Daha fazlası Daha az

Resilience and Redundance: Resource Networks and the Neolithic Chert Economy at Catalhoyuk, Turkey

Nazaroff, Adam Joseph | Baysal, Adnan | Ciftci, Yahya | Prufer, Keith

Article | 2015 | EUROPEAN JOURNAL OF ARCHAEOLOGY18 ( 3 ) , pp.402 - 428

The polycentric nature of Neolithic developments in the Middle East has prompted several discussions related to the processes driving regional diversification in the emergence of agglomerate societies. Archaeologists have recognized how diverse social, environmental, and material landscapes shaped various communities, resulting in a heterogenous Neolithic world. In this paper, we use portable x-ray fluorescence analysis to determine the use of different chert resources at the site of Catalhoyuk, Turkey, and question how their consumption affected, and was affected by, different social and material practices enacted within the commun . . .ity. We adopt a network perspective to examine the range of behaviours that consumed particular resources, and trace how alterations in these networks impacted the social fabric of Catalhoyuk. Ultimately, we conclude that different investments involved in the consumption of each resource either promoted or restricted their use through time. A more complete picture of Neolithic life, we suggest, takes note of the varied relationships that communities developed with nearby social and environmental landscapes, including nuances in the ways in which resources were incorporated into different facets of each community Daha fazlası Daha az

THE DYNAMICS OF POSITIVE SOLUTIONS OF A HIGHER ORDER FRACTIONAL DIFFERENCE EQUATION WITH ARBITRARY POWERS

Gumus, Mehmet | Soykan, Yuksel

Article | 2017 | JOURNAL OF APPLIED MATHEMATICS & INFORMATICS35 ( 03.Apr ) , pp.267 - 276

The purpose of this paper is to investigate the local asymptotic stability of equilibria, the periodic nature of solutions, the existence of unbounded solutions and the global behavior of solutions of the fractional difference equation x(n+1) = alpha xn-(k+1)/beta+gamma x(n)(p) (k)x(n)(g)-(k+2), n =0,1... where the parameters alpha, beta, gamma; p, q are non-negative numbers and the initial values x - (k + 2), x -(k + 1),..., x-1; x(0) is an element of R+.

Preoperative Evaluation of Lymph Node Metastases in Patients with Gastric Cancer: An Analysis of Imaging Methods

Günay, Yusuf | Çağlar, Emrah | Korkmaz, Esin | Erdemir, Rabiye Uslu | Taşdöven, İlhan | Kozan, Ramazan

Article | 2018 | ACTA ONCOLOGICA TURCICA51 ( 3 ) , pp.276 - 282

INTRODUCTION: Preoperative evaluation is necessary for the surgical treatment of gastric cancer (GC). Nonetheless, there is no single best diagnostic modality to predict lymph node metastases prior to surgery. The aim of this study was to analyze of the diagnostic utility of positron emission tomography-computed tomography (PET-CT) and CT for the preoperative evaluation of lymph node (LN) metastases in GC. METHODS: Eighty seven patients with a history of GC, who underwent gastrectomy and D2 LN dissection were investigated. Imaging test results and pathology reports were collected from the patients’ charts. RESULTS: There was no stat . . .istical differences between PET/CT and CT scans in regard to predicting LN metastases in GC patients (p>0.05). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of PET/CT scans in predicting LN metastases were 55.56%, 54.55%, 55.26%, 75%, and 33.3%, respectively, versus 60.47%, 57.69%, 59.42%, 70.27%, and 46.88% for CT scans, respectively. However, combined PET/CT and CT showed better outcomes and specificity with a PPV of 80% and 88.9%, respectively. No patients or tumor factors were found to increase the accuracy of LN metastasis prediction using either PET/CT or CT scans. DISCUSSION AND CONCLUSION: The combination of CT and PET/CT scans increases the specificity and PPV. This increases the prediction accuracy of LN metastasis in GC patients compared to the use of each type of imaging modality alone. INTRODUCTION: Preoperative evaluation is necessary for the surgical treatment of gastric cancer (GC). Nonetheless, there is no single best diagnostic modality to predict lymph node metastases prior to surgery. The aim of this study was to analyze of the diagnostic utility of positron emission tomography-computed tomography (PET-CT) and CT for the preoperative evaluation of lymph node (LN) metastases in GC. METHODS: Eighty seven patients with a history of GC, who underwent gastrectomy and D2 LN dissection were investigated. Imaging test results and pathology reports were collected from the patients’ charts. RESULTS: There was no statistical differences between PET/CT and CT scans in regard to predicting LN metastases in GC patients (p>0.05). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of PET/CT scans in predicting LN metastases were 55.56%, 54.55%, 55.26%, 75%, and 33.3%, respectively, versus 60.47%, 57.69%, 59.42%, 70.27%, and 46.88% for CT scans, respectively. However, combined PET/CT and CT showed better outcomes and specificity with a PPV of 80% and 88.9%, respectively. No patients or tumor factors were found to increase the accuracy of LN metastasis prediction using either PET/CT or CT scans. DISCUSSION AND CONCLUSION: The combination of CT and PET/CT scans increases the specificity and PPV. This increases the prediction accuracy of LN metastasis in GC patients compared to the use of each type of imaging modality alone Daha fazlası Daha az

Examining with Discrimanant Analysis the Differences of Automobile Consumers at the Stage of Information Searching in Zonguldak Region

Albayrak, Ali Sait | Aksoy, Ramazan

Article | 2007 | Yönetim Dergisi:İstanbul Üniversitesi İşletme Fakültesi İşletme İktisadı Enstitüsü18 ( 56 ) , pp.40 - 52

Satın alma sürecinde tüketicilerin bilgi edinmeleri aşaması en sorunlu aşamadır. Bu aşamada, tüketiciler hangi bilgi kaynaklarına başvuracağına karar vermede önemli güçlüklerle karşılaşmaktadır. Bu çalışmada otomobil tüketicilerinin cinsiyet, medeni durum, eğitim düzeyi, gelir düzeyi, yaş grubu ve otomobil sahipliliği yönünden bilgi türleri ve bilgi kaynaklan itibariyle farklılık gösterip göstermediği diskriminant analiziyle araştırılmaktadır. Diskriminant analizi, varsayımları (çoklu normal dağılım, eşit kovaryans, çoklu doğrusal bağlantı ve doğrusallık) sağlanması durumunda en uygun sınıflandırma tekniğidir. Diskriminant analizini . . .n sonuçları otomobil tüketicileri arasında cinsiyet, medeni durum, eğitim ve gelir düzeyi, yaş grubu ve otomobil sahipliliği yönünden bilgi türleri ve bilgi kaynakları itibariyle anlamlı farklılıkların olduğunu göstermektedir. Consumers' information search is the most troubled phase of the purchasing decision process. In this phase, consumers have trouble deciding which information type and information source to approach. In this study, whether consumers differ by their sex, marital status, educational level, income level, age group and ownership of goods in respect to their demand for information type and preferred information source is examined with discriminant analysis. When the assumptions (multivariate normality, equal covariance matrices, multicolinearity and linearity) of discriminant analysis are met, then discriminant analysis is the most appropriate classification technique. The discriminant analysis results point out that the discriminant functions of sex, marital status, educational level, income level, age group and ownership of goods in respect to their demand for information type and preferred information source account for a meaningful proportion of the differences among the groups Daha fazlası Daha az

Evaluation of Critical Operational Faults of Marine Diesel Generator Engines by Using DEMATEL Method

Başhan, Veysi | Demirel, Hakan

Article | 2018 | Journal of Eta Maritime Science6 ( 2 ) , pp.119 - 128

All the electrical demand of ship are provided by diesel generators (DG). Failure of generators due to breakdown can lead to the blackout of the ship which may suddenly cause serious damage to ship’s main and/or auxiliary engines, human health and marine environment or any structure at ship’s route. Thus, the planned maintenance and repairs of the generators must be done properly without any deficiency or delay. And even then, since the generators run continuously failures may often occur. In this context, this paper provides a DEMATEL (Decision Making Trial and Evaluation Laboratory) method to evaluate the critical operational faul . . .ts in marine DGs. The DEMATEL method enables to identify and analyze the important faults of marine DG within the respect to the cause-effect relationship diagram. The obtained results of the research will contribute to ship safety at sea and prevention of hazardous machinery effects. Geminin tüm elektriksel gereksinimleri dizel jeneratörler tarafından sağlanmaktadır. Jeneratörlerde meydana gelen arızalar geminin kararmasına (çökmesine) neden olabilir ve bu durum aniden gemi ana makinesi veya yardımcı makinelerinde, insan sağlığına, deniz çevresine veya geminin rotasındaki herhangi bir yapıya ciddi hasarlar verebilir. Bu yüzden, jeneratörlerin planlı bakım ve onarımları düzgün bir şekilde eksiksiz ve zamanında yapılmalıdır. Tüm bunlara rağmen, sürekli çalışan jeneratörlerde arızalar olabilmektedir. Bu kapsamda, bu makale gemi dizel jeneratörlerinde kritik operasyonel arızaları DEMATEL (Karar Verme Deneme ve Değerlendirme Laboratuvarı) metoduyla sunmaktadır. DEMATEL metodu gemi dizel motorlarında meydana gelen önemli arızaları sebep-etki ilişkisi diyagramıyla tanımlanma ve analiz etmeye yaramaktadır. Elde edilen sonuçlar, denizde gemi emniyeti ve tehlikeli makine etkilerinin önlenmesine katkıda bulunacaktır Daha fazlası Daha az

Capital Structure in an Emerging Stock Market: The Case of Turkey*

Akman, Engin | Gokbulut, Rasim Ilker | Temel, Halime Nalın | Gokbulut, Elif

Article | 2015 | Çankırı Karatekin Üniversitesi İktisadi ve İdari Bilimler Fakültesi Dergisi5 ( 2 ) , pp.639 - 660

Sermaye yapısı bir işletmenin faaliyetlerinin planlanmasında ve gerçekleştirilmesinde önemli olan ve aynı zamanda bu faaliyetlerin sonucu olarak şekillenen bir faktördür. Bu çalışmanın amacı, Türkiye’deki işletmelerin sermaye yapısına etki eden firmaya özgü belirleyicileri değişen ekonomik koşullar altında incelemektir. Bu çalışmada 2003-2011 yılları arasında Borsa İstanbul’da işlem gören üretim işletmelerinden elde edilen verilere panel veri analizi uygulanmıştır. Elde edilen sonuçlara göre, dengeleme, finansman hiyerarşisi ve piyasa zamanlaması gibi geleneksel sermaye yapısı teorileri, gelişmekte olan bir ülkenin işletmelerinden o . . .luşan örneklemin sermaya yapılarını açıklamakta yetersiz kalmıştır. Bunun ana nedeni, bu teorilerin gelişmiş ülkeler için geçerli olan varsayımlara dayandırılmış olmasıdır. Capital structure is an important factor in planning and realising operations of a company. Operations and decisions of a company shape the capital structure. The aim of this paper is to investigate the firm-specific determinants of capital structure under changing economic conditions in Turkey. The paper applies panel data analysis for manufacturing firms listed on the Borsa Istanbul (BIST) over the period of 2003-2011. Results show that, established theories such as trade-off, pecking order, and market timing fail to explain the observed leverages adequately, largely made up of short time debts. This outcome is not surprising as most of the assumptions of these theories are effective for the developed markets, which are not in force in the developing countries Daha fazlası Daha az

SUFFERING FOR THE SAKE OF COSMIC ORDER: TWELVER SHI?AH ISLAM'S COPING WITH TRAUMA

Shirinov, Agil

Article | 2017 | İlahiyat Studies: A Journal on Islamic and Religious Studies8 ( 1 ) , pp.65 - 93

The relation established in Shi?ite Islam between suffering, cosmicorder, and the position attributed to the Shi?ite community in thiscosmic order, is very important in terms of understanding Shi?iteIslam identity. This article's primary claim is that a deep investigationof Shi?ite-Islam identity should be conducted in the context of itscoping with the trauma of the tragedy of Karbala?. Based on JeffreyAlexander's definition of trauma as a "cultural construction," we claimthat the coding, weighting, and narrating of the Karbala? tragedy inthe course of the trauma process can provide us with important cluesto understand the . . . Shi?ite-Islam identity. This article claims that in theShi?ite identity, the suffering experienced in Karbala? is considered aguarantee that cosmic order will be maintained. Suffering isinterpreted as the cost of the battle between the haqq (truth) and batil(falsehood) and of preserving the right way; thus, suffering is glorifiedand transformed into a social activity of continuous character. In thisway, the Shi?ite community places itself both as "a subject of history"and as a dynamic social tradition. The relation established in Shi?ite Islam between suffering, cosmicorder, and the position attributed to the Shi?ite community in thiscosmic order, is very important in terms of understanding Shi?iteIslam identity. This article's primary claim is that a deep investigationof Shi?ite-Islam identity should be conducted in the context of itscoping with the trauma of the tragedy of Karbala?. Based on JeffreyAlexander's definition of trauma as a "cultural construction," we claimthat the coding, weighting, and narrating of the Karbala? tragedy inthe course of the trauma process can provide us with important cluesto understand the Shi?ite-Islam identity. This article claims that in theShi?ite identity, the suffering experienced in Karbala? is considered aguarantee that cosmic order will be maintained. Suffering isinterpreted as the cost of the battle between the haqq (truth) and batil(falsehood) and of preserving the right way; thus, suffering is glorifiedand transformed into a social activity of continuous character. In thisway, the Shi?ite community places itself both as "a subject of history"and as a dynamic social tradition Daha fazlası Daha az

Comparison of drillability and abrasivity properties of rocks [Kayaçlari{dotless}n delinebilirlik ve aşi{dotless}ndi{dotless}ri{dotless}ci{dotless}li{dotless}k özelliklerinin karşi{dotless}laşti{dotless}ri{dotless}lmasi{dotless}]

Çapik M. | Yilmaz A.O. | Yaşar S. | Yarali O. | Çavuşoglu I.

Conference Object | 2013 | 23rd International Mining Congress and Exhibition of Turkey, IMCET 20131 , pp.659 - 669

Drillability is defined as the penetration rate of a drill bit into the rock. Abrasion is broken off by the tools during the excavation of rocks. Different types of rock formations have different abrasiveness and hardness properties and that is significantly affected excavatability and drillability in the mechanical excavation systems. Because, abrasive rocks and hard rocks lead to an increase of the cost excavation, decrease of the penetration rate and atrophy of the cutter in a short time. This study was carried out in Hopa-Borcka (Artvin) Cankurtaran Highway Tunnel. Rock samples were obtained from Cankurtaran Tunnel at the changi . . .ng rock formations for the laboratory studies. The test samples were prepared at the appropriate size and quantity. Sievers J-miniature drill test (SJ) and the brittleness tests were carried out and for the drilling rate index values were calculated. Cerchar Abrasivity Index (CAI), Norway Abrasion Value (AV) and Bohme abrasion tests were carried out and for abrasiveness of rock properties. Uniaxial compressive strength, point load strength and Brazilian tensile strength tests were determined for the calculations mechanical properties of rock Daha fazlası Daha az

Clodronic acid in the treatment of postmenopausal osteoporosis

Tanakol R. | Yarman S. | Bayraktaroglu T. | Boztepe H. | Alagöl F.

Article | 2007 | Clinical Drug Investigation27 ( 6 ) , pp.419 - 433

Background: Clodronic acid, a first-generation bisphosphonate, has been successfully used in the treatment of high bone turnover states, Paget's disease and osteolytic bone metastases. However, controversies remain over its optimal dosage and method of administration in the treatment of postmenopausal osteoporosis. In this study we aimed to evaluate the effect of clodronic acid treatment for 3 years on bone mineral density (BMD) in women with postmenopausal osteoporosis. Methods: This was a prospective, open-label, randomised, controlled study that was conducted in an outpatient clinic at the Bone Metabolism Unit of a tertiary refer . . .ral centre university hospital. Thirty postmenopausal women (age range 48-73 years) with osteoporosis and a control group of 49 osteoporotic women (age range 47-74 years) received randomised therapy. The clodronic acid group of participants received oral doses of clodronic acid 800mg plus elemental calcium 500mg and 400IU of vitamin D daily, while the control group was treated with calcium and vitamin D only. BMD was measured by dual energy x-ray absorptiometry at yearly intervals. Biochemical markers of bone turnover were also measured. Results: In this clinical study of postmenopausal women with osteoporosis, 36 months of clodronic acid treatment significantly increased average femoral neck BMD by 3.2 ± 2.9%, trochanter BMD by 2.2 ± 2.9% and lumbar spine BMD by 3.1 ± 3%. In the control group, femoral neck, trochanter and lumbar spine BMD decreased by -6 ± 2.7%, -7.3 ± 2.5% and -5.4 ± 2%, respectively (p < 0.01, p < 0.05 and p < 0.05 for clodronic acid vs control, respectively). There was a significant decrease in urinary hydroxyproline (-38.3%) over 3 years in the clodronic acid group compared with baseline (p < 0.05), while no significant change occurred in the control group. Clodronic acid was well tolerated and compliance was good. There were no clinically meaningful differences in the incidence of individual adverse events between the groups. Conclusion: These results indicate that daily oral administration of clodronic acid 800mg provides benefits to skeletal bone density in osteoporotic postmenopausal women. Calcium and vitamin D supplementation alone did not prevent further bone loss. © 2007 Adis Data Information BV. All rights reserved Daha fazlası Daha az

6698 sayılı Kişisel Verilerin Korunması Kanunu kapsamında yükümlülüklerimiz ve çerez politikamız hakkında bilgi sahibi olmak için alttaki bağlantıyı kullanabilirsiniz.

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