Soluble, Colloidal, and Particulate Iron Across the Hydrothermal Vent Mixing Zones in Broken Spur and Rainbow, Mid-Atlantic Ridge

The slow-spreading Mid-Atlantic Ridge (MAR) forms geological heterogeneity throughout the ridge system by deep crustal faults and their resultant tectonic valleys, which results in the existence of different types of hydrothermal vent fields. Therefore, investigating MAR hydrothermal systems opens a gate to understanding the concentration ranges of ecosystem-limiting metals emanating from compositionally distinct fluids for both near-field chemosynthetic ecosystems and far-field transport into the ocean interiors. Here, we present novel data regarding onboard measured, size-fractionated soluble, colloidal, and particulate iron concentrations from the 2018 R/V L'Atalante - ROV Victor research expedition, during which samples were taken from the mixing zone of black smokers using a ROV-assisted plume sampling. Iron size fractionation (200nm) data were obtained from onboard sequential filtering, followed by measurement via ferrozine assay and spectrophotometric detection at 562nm. Our results showed the persistent presence of a nanoparticulate/colloidal phase (retained within 20-200nm filtrates) even in high-temperature samples. A significant fraction of this phase was retrievable only under treatment with HNO3 - a strong acid known to attack and dissolve pyrite nanocrystals. Upon mixing with colder bottom waters and removal of iron in the higher parts of the buoyant plume, the larger size fractions became dominant as the total iron levels decreased, but it was still possible to detect significant (micromolar) levels of nanoparticulate Fe even in samples collected 5m above the orifice in the rising plume. The coolest sample

Determination of Chemisorption Probabilities of Hydrogen Molecules on a Nickel Surface by Artificial Neural Network

Dissociative chemisorption probabilities for H2(v, j) + Ni(100) collision systems have been estimated by using Artificial Neural Network (ANN). For training, previously determined probability values via molecular dynamics simulations have been used. Performance of the ANN, for predicting any quantities in the molecule-surface interaction, has been investigated. Effects of the surface sites and the rovibrational states of the molecule on the process are analyzed. The results are in good agreement with the related previous studies

3+1 Essays on the Turkish economy

Cataloged from PDF version of article.This dissertation comprise of four essays. The first essay studies the relationship between treasury auction maturity and auction interest rates. Using the Turkish auction data from 1988 to 2004, a reciprocal linkage between auction interest rates and maturities is observed, especially for the 1995-2000 period. This suggests that under an adverse shock, treasury decreases the auction maturity in order not to increase interest rates too much. A change in this reciprocal relationship is also reported for the post-2001 era. The second essay assesses the effect of USD-Euro parity on a small open economy for an economy where its exports are predominantly denominated in Euros and imports are denominated in USD. The empirical evidence suggests that a positive innovation in USD-Euro parity appreciates the local currency, decreases inflation and increases output. The third essay studies the relationship between on-budget and off-budget expenditures in Turkey and concludes that information content of the budget deficit statistics is not empty; however, it might be misleading in assessing fiscal stance for Turkey. The final essay investigates the connection between Turkish industrial production performance and the success of a popular Turkish football team, namely Fenerbahce. The success of Fenerbahce is interpreted as a proxy for the workers' mood or morale. Performing a transfer function analysis on my monthly data set, I reveal a positive feedback from Fenerbahce's success, which proxies workers' mood/morale, to economic performance. Evidence of the effects of games against domestic rivals on industrial performance is not statistically significant.Yücel, Mustafa ErayPh.D

Testing Marshall-Lerner Condition: a non-parametric approach

Ankara : The Department of Economics, Bilkent Univ., 2000.Thesis (Master's) -- Bilkent University, 2000.Includes bibliographical references leaves 54-57.This study examines the determinants of trade flows for six developed countries. Volume of imports (exports) is regressed on relative import (export) price and domestic (world) real income using non-parametric kernel estimation techniques. On quarterly data, Local Constant Least Squares (LCLS) and Local Linear Least Squares (LLLS) estimates of trade elasticities are obtained. Using pointwise and point estimates of these elasticities, the Marshall-Lemer Condition is checked for our sample countries. The condition is satisfied for two of our six sample countries. Although the existing controversy on the subject has not been solved using non-parametric regression techniques, a new room is opened for further investigation by presenting the time-behaviour of trade elasticities.Yücel, Mustafa ErayM.S

Üst jura – alt kretase inalti formasyonu’nun mikropaleontolojik ve stratigrafik analizi (Bürnük, orta pontidler, Türkiye) : fasiyes evrimi üzerine notlar.

This thesis aims to conduct a thorough investigation on the Upper Jurassic – Lower Cretaceous İnaltı Formation which is a significant unit for the regional geology of Turkey. Conducted investigation involves micropaleontological and microfacies analyses integrated with stratigraphic interpretations. In the vicinity of Bürnük Village, a 395 m thick stratigraphic section, overlying the Bürnük Formation and underlying the Çağlayan Formation, was measured and 101 samples were collected. Biostratigraphic and chronostratigraphic works are based on the benthic foraminifera and encrusting sponge Calcistella jachenhausenensis. 44 species of foraminifera belonging to 35 genera, and 13 species of microencrusters were identified and 3 biozones were established. The biozones are Mesoendothyra izjumiana zone, Calcistella jachenhausenensis zone and Protopeneroplis ultragranulata zone in ascending order. Detailed microfacies analysis revealed the depositional history and carbonate platform evolution in the area. 15 microfacies types were determined in 5 different environments corresponding to slope, fore-reef, reef, back-reef and lagoonal environments on the carbonate platform. A vertical facies shift from platform margin (reef, fore-reef) - slope facies to inner platform (back reef-lagoonal) facies was observed in the Berriasian. Before cutting by Çağlayan clastics, again a facies shift towards the platform margin-slope facies took place in the studied part of the İnaltı carbonate platform. The studied section was correlated with some J-K boundary sections from different parts of the world. It is concluded that mentioning a general shallowing trend at/around the J-K boundary for all the correlated sections is not possible due to the preponderant local tectonics.M.S. - Master of Scienc

COVID-19 and urology: A bibliometric analysis of the literature

Aim The aims of this research were to analyse the urological literature published during the COVID-19 pandemic and to guide future research. Material and methods Between 2019 and 2021, the Web of Science (WoS) All Databases collection was searched for publications related to COVID-19 and Urology. The keywords used during this search were coronavirus-19, COVID-19, SARS-CoV-2, novel coronavirus, 2019-nCoV, pandemic and/or urology. The top 50 cited (T50) publications were also identified and summarized. Exported Microsoft Excel files, Visualization of Similarities viewer (VOSviewer) software and descriptive assessment were used for bibliometric and statistical analyses of the publications. Results In total, 582 publications related to COVID-19 and urology were identified. In these publications, the most active author, journal, country and organisation were Francesco Porpiglia, European Urology, the United States of America (USA) and La Paz University Hospital, respectively. The most commonly used keywords were telemedicine-telehealth, SARS-CoV-2, coronavirus, pandemic, residency, testicle, semen, kidney transplantation, endourology and surgery. The most worrying issues in the articles are the negative impact of COVID-19 on resident training and permanent damage to urological organs. Conclusions We analysed all the articles related to COVID-19 and urology published to date in the WoS All Databases collection. The most commonly published articles were based on clinical and outpatient practice, telemedicine, residency training, transplantation, and testicles. The long-term adverse effects of the pandemic on urology practice and especially urological organs will need to be assessed further in future research

Microbial Sulfide Filter along a Benthic Redox Gradient in the Eastern Gotland Basin, Baltic Sea

The sediment-water interface is an important site for material exchange in marine systems and harbor unique microbial habitats. The flux of nutrients, metals, and greenhouse gases at this interface may be severely dampened by the activity of microorganisms and abiotic redox processes, leading to the “benthic filter” concept. In this study, we investigate the spatial variability, mechanisms and quantitative importance of a microbially-dominated benthic filter for dissolved sulfide in the Eastern Gotland Basin (Baltic Sea) that is located along a dynamic redox gradient between 65 and 173 m water depth. In August-September 2013, high resolution (0.25 mm minimum) vertical microprofiles of redox-sensitive species were measured in surface sediments with solid-state gold-amalgam voltammetric microelectrodes. The highest sulfide consumption (2.73–3.38 mmol m−2 day−1) occurred within the top 5 mm in sediments beneath a pelagic hypoxic transition zone (HTZ, 80–120 m water depth) covered by conspicuous white bacterial mats of genus Beggiatoa. A distinct voltammetric signal for polysulfides, a transient sulfur oxidation intermediate, was consistently observed within the mats. In sediments under anoxic waters (>140 m depth), signals for Fe(II) and aqueous FeS appeared below a subsurface maximum in dissolved sulfide, indicating a Fe(II) flux originating from older sediments presumably deposited during the freshwater Ancylus Lake that preceded the modern Baltic Sea. Our results point to a dynamic benthic sulfur cycling in Gotland Basin where benthic sulfide accumulation is moderated by microbial sulfide oxidation at the sediment surface and FeS precipitation in deeper sediment layers. Upscaling our fluxes to the Baltic Proper; we find that up to 70% of the sulfide flux (2281 kton yr−1) toward the sediment-seawater interface in the entire basin can be consumed at the microbial mats under the HTZ (80–120 m water depth) while only about 30% the sulfide flux effuses to the bottom waters (>120 m depth). This newly described benthic filter for the Gotland Basin must play a major role in limiting the accumulation of sulfide in and around the deep basins of the Baltic Sea

Redox processes as revealed by voltammetry in the surface sediments of the Gotland Basin, Baltic Sea

Sulfur cycling in marine sediments undergoes dramatic changes with changing redox conditions of the overlying waters. The upper sediments of the anoxic Gotland Basin, central Baltic Sea represent a dynamic redox environment with extensive mats of sulfide oxidizing bacteria covering the seafloor beneath the chemocline. In order to investigate sulfur redox cycling at the sediment-water interface, sediment cores were sampled over a transect covering 65 – 174 m water depth in August-September 2013. High resolution (0.25 mm minimum) vertical microprofiles of electroactive redox species including dissolved sulfide and iron were obtained with solid state Au-Hg voltammetric microelectrodes. This approach enabled a fine-scale comparison of porewater profiles across the basin. The steepest sulfide gradients (i.e. the highest sulfide consumption) occurred within the upper 10 mm in sediments covered by surficial mats (2.10 to 3.08 mmol m-2 day-1). In sediments under permanently anoxic waters (>140m), voltammetric signals for Fe(II) and aqueous FeS were detected below a subsurface maximum in dissolved sulfide, indicating a Fe flux originating from older, deeper sedimentary layers. Our results point to a unique sulfur cycling in the Gotland basin seafloor where sulfide accumulation is moderated by sulfide oxidation at the sediment surface and by FeS precipitation in deeper sediment layers. These processes may play an important role in minimizing benthic sulfide fluxes to bottom waters around the major basins of the Baltic Sea

Kargo Hizmetlerinin Pazarlanmasında Tüketici tercihlerini Etkileyen Faktörler: Malatya’da Bir Alan Çalışması

Toplumların ekonomik kalkınma sürecinde hizmetler sektörü, iktisadi gelişmeye katkısıbakımından en önemli sektörler içerisinde yer almaktadır. Taşımacılık hizmetleri ise, hizmetler sektörü içerisinde yarattığıkatma değer, istihdam ve diğer ekonomik göstergeler açısından önemli bir konuma sahiptir. Özellikle günümüzde ekonomik globalizasyonun tüm sektörlerde etkisini hissettirmesiyle birlikte hizmetler sektörü içerisinde taşımacılığın önemi daha fazla artmıştır. Küreselleşme ile birlikte hemen her alanda görülen değişim ve gelişim işletme dünyasınıda etkisi altına almıştır. İşletmeler artan rekabet baskısıaltında günümüzün bilinçli tüketicilerinin gözünde fark edilebilir olmaya çalışmaktadır. Fark edilebilme ile birlikte tercih edilmek ve bunda sürekliliği sağlayabilmek “tüketici odaklı” yaklaşımların benimsenmesini gerekli kılmaktadır. Bu noktada lojistik faaliyetler ve kargo hizmetlerinin sunumu büyük bir önem kazanmaktadır. Türkiye birçok alanda kavramlarıyabancıkaynaklardan edinmiştir. Bu da beraberinde sınıflandırma ve tanımlama yapmada ya da uluslararasıboyutta karşılaştırma yapma da bazızorluklarıberaberinde getirmektedir. Yabancıkaynaklarda, kargo; öncelikli olarak denizyolu ve havayolu sektörlerinde kullanılan ve “yük” kelimesinin diğer bir manası şeklinde tanımlanmaktadır.Kargo ve kargo işletmecisi kavramlarıTürkiye’de ise, kargo, “Tekparçada en fazla yüz kilo gramıgeçmeyen genellikle ambalaj ve kap içerisinde olan küçük boyutlu koli, sandık, paket gibi parça eşya” şeklinde tanımlanırken, kargo işletmecisi ise, “bağımsız bir işyerinin kullanma hakkına sahip olan ve kargoyu teslim alarak kısa sürede gönderilene ulaştırmak amacıyla kendi gözetimi ve denetimi altında yükleme, boşaltma, depolama, istifleme, aktarma ve gönderilene teslim gibi hizmetleri yerine getiren, taşımayıyapan ve ya yaptıran ve bundan doğacak sorumluluğu üstlenen kişi” şeklinde tanımlanmaktadır. Hizmetlerin pazarlanmasında karşılaşılan sorunlar çok değişik ve çözümleri daha zordur. Bir hizmet sektörü olan taşımacılık, ülke içinde ve dışında sosyal, ekonomik ve politik kararlardan etkilenen sektörlerin basında gelmektedir. Sektörün oluşumu, gelişimi ve yönlendirilmesi değişken faktörlere bağlıdır. Taşımacılık bir hizmet üretimidir. Hizmeti sunan; taşıyıcılar, acenteler, sigorta İsletmeleri ve gümrük komisyoncularıbirbirleriyle iliksi ve işbirliği içersindedirler. Bu isletmelerin faaliyetleri birbirinden ayrılmaz bir bütündür. Sektörde rekabet fiyata dayalıdır. Kargo şirketlerinin pek çoğu hizmette kalite ile değil, daha ucuz tasıma mantığıile hareket etmektedirler. Bu durum hizmette kaliteyi olumsuz yönde etkilemektedir. Türkiye’de kargo taşımacılık hizmetlerine yönelik araştırmaların yok denecek kadar az olması, bu çalışmanın yapılmasında en önemli teşvik edici unsur olmuştur. Bu çalışmanın temel hedefi: araştırmacıların ilgisini bu alana çekmek ve mevcut koşullarda sunulan kargo taşımacılık hizmetlerinin pazarlanmasıve kalitesi ile ilgili incelemelerde bulunmaktır. Çalışmada hedeflenen nihai sonuç: kargo taşımacılık hizmetlerinin pazarlanmasıve hizmet kalitesinin geliştirilmesi konusunda kargo firmalarına yol göstermek ve çözüm önerilerinde bulunmaktır.. Çalışmanın ana kütlesini Malatya ilinde bulunan İnönü Üniversitesi bünyesinde görev yapmakta olan akademik personel oluşturmaktadır. Konu üzerine literatürde çok az çalışma bulunmasınedeniyle bu çalışma sonucunda elde edilen verilerin sektör ve araştırmacılar için yararlıbir kaynak olabileceği düşünülmektedir

Use of spent foundry sand and fly ash for the development of green self-consolidating concrete

In the United States alone, the foundry industry discards up to 10 million tons of sand each year, offering up a plentiful potential resource to replace sand in concrete products. However, because the use of spent foundry sand (SFS) is currently very limited in the concrete industry, this study investigates whether SFS can successfully be used as a sand replacement material in cost-effective, green, self-consolidating concrete (SCC). In the study, SCC mixtures were developed to be even more inexpensive and environmentally friendly by incorporating Portland cement with fly ash (FA). Tests done on SCC mixtures to determine fresh properties (slump flow diameter, slump flow time, V-funnel flow time, yield stress, and relative viscosity), compressive strength, drying shrinkage and transport properties (rapid chloride permeability and volume of permeable pores) show that replacing up to 100% of sand with SFS and up to 70% Portland cement with FA enables the manufacture of green, lower cost SCC mixtures with proper fresh, mechanical and durability properties. The beneficial effects of FA compensate for some possible detrimental effects of SFS.Natural Sciences and Engineering Research Council (NSERC) of Canada, and the Canada Research Chair Progra