Ensemble Inequivalence in Single Molecule Experiments

In bulk systems the calculation of the main thermodynamic quantities leads to the same expectation values in the thermodynamic limit, regardless of the choice of the statistical ensemble. Single linear molecules can be still regarded as statistical systems, where the thermodynamic limit is represented by infinitely long chains. The question of equivalence between different ensembles is not at all obvious and has been addressed in the literature, with sometimes contradicting conclusions. We address this problem by studying the scaling properties of the ensemble difference for two different chain models, as a function of the degree of polymerization. By characterizing the scaling behavior of the difference between the isotensional (Gibbs) and isometric (Helmholtz) ensembles in the transition from the low-stretching to the high-stretching regime, we show that ensemble equivalence cannot be reached for macroscopic chains in the low force regime, and we characterize the transition from the inequivalence to the equivalence regime.Comment: Typos in equations fixed. Reference list updated and corrected. Extende

The trend of breeding value research in animal science: bibliometric analysis

This study aims to identify trends and hot topics in breeding value to support researchers in finding new directions for future research in that area. The data of this study consist of 7072 academic studies on breeding value in the Web of Science database. Network visualizations and in-depth bibliometric analysis were performed on cited references, authors, countries, institutions, journals, and keywords through CiteSpace. VanRaden (2008) is the most cited work and has an essential place in the field. The most prolific writer is Ignacy Misztal. While the most productive country in breeding value studies is the United States, the People's Republic of China is an influential country that has experienced a strong citation burst in the last 3 years. The National Institute for Agricultural Research and Wageningen University are important institutions that play a critical role in connecting other institutions. Also, these two institutions have the highest centrality values. “Genomic prediction” is the outstanding sub-study field in the active clusters appearing in the analysis results. We have summarized the literature on breeding value, including publication information, country, institution, author, and journal. We can say that hot topics today are “genome-wide association”, “feed efficiency”, and “genomic prediction”. While the studies conducted in the past years have focused on economic value and accuracy, the studies conducted in recent years have started to be studies that consider technological developments and changing world conditions such as global warming and carbon emission.</p

Theory of mechanical unfolding of homopolymer globule: all-or-none transition in force-clamp mode vs phase coexistence in position-clamp mode

Equilibrium mechanical unfolding of a globule formed by long flexible homopolymer chain collapsed in a poor solvent and subjected to an extensional force f (force-clamp mode) or extensional deformation D (position-clamp mode) is studied theoretically. Our analysis, like all previous analysis of this problem, shows that the globule behaves essentially differently in two modes of extension. In the force-clamp mode, mechanical unfolding of the globule with increasing applied force occurs without intramolecular microphase segregation, and at certain threshold value of the pulling force the globule unfolds as a whole ("all-or-none" transition). The value of the threshold force and the corresponding jump in the distance between the chain ends increase with a deterioration of the solvent quality and/or with an increase in the degree of polymerization. In the position-clamp mode, the globule unfolding occurs via intramolecular microphase coexistence of globular and extended microphases followed by an abrupt unraveling transition. Reaction force in the microphase segregation regime demonstrates an "anomalous" decrease with increasing extension. Comparison of deformation curves in force and position-clamp modes demonstrates that at weak and strong extensions the curves for two modes coincide, differences are observed in the intermediate extension range. Another unfolding scenario is typical for short globules: in both modes of extension they unfold continuously, without jumps or intramolecular microphase coexistence, by passing a sequence of uniformly elongated configurations.Comment: 19 pages, 13 figures, 1 tabl

Süphan stratovolkanı'nın volkanostratigrafisi ve jeokimyasal evrimi

TÜBİTAK MAG01.09.2009Doğu Anadolu Bölgesinde yer alan çarpışma kökenli volkanizma kuzeydoğuda Erzurum-Kars Platosundan güneyde Karacadağ’a kadar uzanan geniş bir alanda yüzeylenmektedir. Bölgenin yaklaşık olarak 2/3 sini kaplayan volkanizma irili ufaklı çıkış merkezleri ile büyük hacimlere sahip kalkan ve stratovolkanlar ile karakterize edilir. Van Gölü’nün kuzeyinde yer alan Süphan Stratovolkanı 4050 m yüksekliği ile Doğu Anadolu’da yer alan Kuvaterner yaşlı volkanların en önemli üyelerinden biridir. Neojen-Kuvaterner yaşlı sedimanter birimler üzerine yerleşen Süphan volkanizmasının ilk ürünleri debris avalanche, I. evre piroklastik ürünler ve riyolitik obsidiyen lavlarıdır. Bu birimlerin üzerine ise bazalttan riyolite kadar uzanan lav akışları, riyolitik/dasitik domlar, piroklastik birimler gelmektedir. Volkanizmanın en son ürünleri ise Aygır Maarı’na ait piroklastik birimlerdir. Mineralojik-Petrografik çalışmalar ve lavların major-iz element karakteristikleri volkanizmanın gelişiminde plajiyoklaz + olivin + klinopiroksen + ortopiroksen + amfibol + biyotit + K-felsdpat fraksiyonel kristalleşmesinin etkin olduğunu göstermektedir. Süphan volkanikleri genel olarak subalkali ve alkali karakterler arasında geçiş göstermektedir. İz element içerikleri ele alındığında HFS elemetler LIL elementlere oranla, LRE elementler HRE elementlere oranla zenginleşme göstermiştir. Volkanikler içerisinde yeralan anklavların jeokimyasal özellikleri Süphan volkanizmasının genel karakteri ile uyum göstermektedir. Th/Y-Nb/Y ve izotop korelasyon diyagramları (87Sr/86Sr -143Nd/144Nd, 87Sr/86Sr – Pb206/Pb204, Pb207/204-Pb206/204) volkanizmanın kaynağının dalma-batma bileşeni ile zenginleşmiş bir manto kaynağı olduğunu işaret etmektedir. Bununla birlikte Ba/Nb - Ce/ Nb diyagramı üzerindeki karışım eğrisi de Süphan volkaniklerinin zenginleşmiş bir manto kaynağı ile dalma-batma bileşeni içeren bir kaynağın karışımından oluştuğunu göstermektedir. Doğu Anadolu Bölgesi’nde kabuk kalınlığı ile ilgili jeofizik tabanlı çalışmalar da göz önüne alındığında bu manto kaynağının, dalan levhanın krılması (slab breakoff) yoluyla yitim bileşeni kazanmış astenosferik bir kaynak olabileceği öngörülmüştür. Volkanikler üzerinde gerçekleştirilen Ar-Ar yaş analizleri trakitik lavlar için 0.55±0.34 ile 0.037±0.020 my arasında riyolitik lavlar için ise 0.040±0.022 my yaş vermiştir.Collision-related volcanics in Eastern Anatolia are exposed in a broad zone from the Erzurum-Kars Plateau in the northeast to Karacadağ in the south. Volcanic rocks covered two thirds of the plateau and are characterized by secondary eruption centers and huge shield and stratovolcanoes. Süphan Stratovolcano, located to the north of the Lake Van is one of the most important Quaternary volcanos in Eastern Anatolia with its 4050 m high elevation. Initial products of the Süphan stratovolcano which overly the Neogene-Quaternary sedimentary rocks are the debris avalanche, Ist cycle pyroclastic rocks and rhyolitic obsidian flows. These units are overlain by lava flows with compositions ranging from basalt to rhyolite, rhyolit-dasidic domes and pyroclastic rocks. Aygır maar deposits are the last products of the volcano. Mineralogical-petrographical and major-trace element compositions of the volcanic products point to the effects of plagioclase + olivine + clinopyroxene + ortopyroxene + amphibole + biotite + K-feldspar fractionation in the evolution of the volcanics. Süphan volcanics are transitional between subalkaline and alkaline character. LIL and LRE elements are enriched over HFS and HRE elements respectively. Most of the Süphan enclaves show similar geochemical properties with the Süphan volcanics. Th/Y-Nb/Y and isotope correlation (87Sr/86Sr -143Nd/144Nd, 87Sr/86Sr – Pb206/Pb204, Pb207/204-Pb206/204) diagrams point out a subduction modified enriched mantle source for the source of the volcanics. Mixing curves on Ba/Nb - Ce/ Nb diagrams further suggest that the Süphan volcanics are formed by mixing of an enriched mantle and a source bearing effects of subduction. In the light of geochemical constraints and recent geophysical data regarding lithospheric structure of eastern Anatolia, the source of the Suphan volcanics is interpreted as an astenospheric mantle bearing the effects of previous subduction events via slab breakoff. Ar-Ar ages of the trachytes and rhyolites range between 55±0.34 - 0.037±0.020, 0.040±0.022 ma respectively

Municipal solid waste landfill site selection for the city of Sanliurfa-Turkey: an example using MCDA integrated with GIS

A municipal solid waste (MSW) management system needs solid waste management (SWM) techniques where the presence of a sanitary landfill is vital. One of the most important issues of sanitary landfilling is to locate the facility to an optimal location. Despite the versatility and case-dependent nature of conventional expert-based site selection procedures, the number of sites to be chosen increases with increased population forcing a number of constraints. Consequently, constraints and environmental regulations mechanically mask unsuitable areas, leaving very little areas to be assessed. This turns the situation into a challenging issue for a geographical information system (GIS) used with multi-criteria decision analysis (MCDA), to select optimal site

Lacustrine mineral facies and implications for estimation of palaeoenvironmental parameters: Neogene intervolcanic Pelitçik Basin (Galatean Volcanic Province), Turkey

The mineralogy of the Neogene lacustrine facies of Pelitcik basin was investigated for the purpose of deriving the palaeoenvironmental parameters of this intervolcanic basin. The laboratory studies indicate that dolomite and K-feldspar are the major non-clay minerals in the study area, where plagioclase, analcime, fibrous zeolite and quartz are the minor constituents. Dolomites are found to be non-stoichiometric in chemistry. The clay fraction of the lacustrine facies is composed mainly of dioctahedral smectites. The smectites are rich in Al-Fe indicating a detrital origin. Illite comprises a minor contribution to the clay fraction, where chlorite and kaolinite are found in trace amounts. Based on dolomite stoichiometry and the mineral paragenesis found in the Pelitcik basin, the depositional conditions are suggested to have been a shallow, quiet, perennial lacustrine environment with fresh to slightly saline and slightly alkaline water chemistry. In addition, based on geological and mineralogical constraints, it is suggested that the water chemistry fluctuated during the deposition of the Pazar formation and the lake began its evolution with a hydrologically closed system and completed its evolution with a hydrologically open system