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In this paper, iterative thermal design model of a superheater-desuperheater system mounted a steam boiler working at pressure of 7.5 bar(g) was completed using Mathcad and findings were interpreted with performance analysis. Aim of the desuperheater (atemperator) in the system is to reduce steam temperature to desired values at superheater outlet. Boiler system having Superheater-desuperheater was also investigated at load cases of %100, %80, %60, %50 and %40, and then, this model was prepared with system scenario containing a superheater without desuperheater in terms of boiler and superheater heat values. As a result of the study, it was determined that desuperheater addition has a positive effect on system heat capacity under proper load cases. Based on the study results, it was commented that superheater-desuperheater addition not only can be used because of construction limitations but can be preferred in order to increase boiler efficiency as well., Bu çalışmada, 7,5 bar(g) çalışma basıncına sahip bir buhar kazanına monte edilen bir kızdırıcı-atemperatör sisteminin iteratif ısıl tasarım modeli Mathcad yazılımı ile gerçekleştirilmiş ve elde edilen bulgular performans analizi ile yorumlanmıştır. Atemperatörün sistemdeki görevi kızdırıcı çıkışı buhar sıcaklığını istenilen sıcaklığa düşürmektir. Kızdırıcı-Atemperatör ikilisine sahip kazan sistemi; %100, %80, %60, %50 ve %40 yük koşulları altında incelenen bu sistem, atemperatörsüz bir kızdırıcıya sahip kazan sistemiyle de kazan ve kızdırıcı ısı kapasitesi açısından karşılaştırılmıştır. Bu çalışmalar sonucunda atemperatör eklentisinin, sistem ısı kapasitesine doğru yük şartları uygulandığında olumlu etki gösterdiği belirlenmiştir. Çalışma verilerine dayanarak, doğru yük şartları altındaki kızdırıcı-atemperatör eklentisinin yalnızca konstrüksiyon kısıtlamaları nedeniyle değil, aynı zamanda kazan verimini arttırmak amacıyla da kullanılabileceği yorumu yapılmıştır.

Enterovirus 71 can be a severe pathogen in small children and immunocompromised adults. Virus uncoating is a critical step in the infection of the host cell; however, the mechanisms that control this process remain poorly understood. We applied normal mode analysis and perturbation response scanning to several complexes of the virus capsid and present a coarse-graining approach to analyze the full capsid. We show that our method offers an alternative to expressing the system as a set of rigid blocks and accounts for the interconnection between nodes within each subunit and protein interfaces across the capsid. In our coarse-grained approach, the modes associated with capsid expansion are captured in the first three nondegenerate modes and correspond to the changes observed in structural studies of the virus. We show that the resolution of the analysis may be modified without losing information on the global motions leading to uncoating. Perturbation response scanning revealed that a protomer cannot serve as a functional unit to explain deformations of the capsid. Instead, we define a pentamer as the minimum functional unit to investigate changes within the capsid. From the modal analysis and perturbation response scanning, we locate a hotspot region surrounding the fivefold axis. The range of the effect of these single, hotspot residues extend to 140 angstrom. The perturbation of internal capsid residues in this region displayed greatest propensity to capsid expansion, thus indicating the significant role that the RNA genome may play in triggering uncoating.

Paralel DevletYapılanması (PDY), yapısı, işleyişi ve eylemleri ile Türkiye Cumhuriyetitarihinde eşi benzeri görülmemiş bir terör örgütü olarak karşımıza çıkmıştır. Örgütoluşumuna başladığı yıllarda kendisine “dini” değerler üzerinden toplumsal birzemin hazırlamış ve kendisini eğitim hareketi olarak topluma lanse etmiştir.Toplumun sosyo-psikolojik travmalarına ve devletin yapısal sorunlarınapragmatist bir şekilde yaklaşmış ve ezoterik bir yapıya sahip olması sayesinde asılamacını fark ettirmeden toplumsal bir kabul görmüştür. Hiçbir zaman aktifsiyasete dahil olmayan örgüt, stratejik kamu kurumlarında kadrolaşarak oluşturduğubürokratik oligarşi sayesinde ülke yönetimini ele geçirmeye çalışarak toplumayön vermeyi amaçlamıştır. Bu çalışma Fethullahçı Terör Örgütü’nün gücünübürokratik oligarşiden aldığını iddia etmekle birlikte gerçek amacının ortayaçıktığı 15 Temmuz Darbe girişimine kadar toplumsal kabul görmesinin sosyolojiknedenlere bağlı olduğunu savunmaktadır.Anahtar Kavramlar: Kamu Kurumları, Bürokrasi, FETÖ, Darbe

In this study, an overview of laws of thermodynamics and variable refrigerant flow systems have been investigated. Besides, thermodynamic analysis of a sample variable refrigerant flow system has been evaluated and exergy losses of different working conditions and different refrigerants has been compared. While minimum refrigerant mass flow rate has been occured in simultaneous heating-cooling working condition of the system, maximum refrigerant mass flow rate has been occured in only cooling working condition. When entropy generations and exergy losses analyzed, minimum entropy generations and exergy losses has been appeared in simultaneous heating-cooling working condition. Maximum entropy generations and exergy losses has been appeared in only cooling working condition. When refrigerants are compared, minimum exergy losses has been occured in using refigerant R404. Maximum exergy losses has been occured in using refigerant R410A. With this study, it has been intended to increase the awareness of the subject.

Nowadays lots of heating and cooling systems are available. Variable Refrigerant Flow System is one of these systems. These systems can be used both as a cooling system and a heat pump. Due to said functionally, these systems distinguish in the buildings which need different air conditions in the same time like hotels, schools or hospitals. Furthermore, with the capability of heating and cooling at the same time, these systems contribute to energy conservation. Another important advantage of these systems is that with one outside unit, more than one inside unit can be work. In this study, exergy losses and entropy generations of variable refrigerant flow (VRF) system has been evaluted in different working condition, mass flow rates and refrigerants. Exergy efficiencies that occur as a result of these losses has been determined. Besides, thermoeconomic analysis of system after the exergy analysis and cost calculation which considered exergy have been carried out. With this study, optimum working contidions of VRF systems and refrigerants that has provided minimum exergy losses have been determined. Cost of the system according to exergy has been evaluated considering working conditions and refrigerants. According to analysis it is explained that, the condition in which VRF system heating and cooling simultaneously, is the most efficient working condition. Also the effects of refrigerants and mass flow rate of refrigerant to exergy efficiency and cost of the system according to exergy has been revealed.

Bu çalışmada, termodinamik kanunlarına genel bir giriş yapılmış ve değişken soğutucu akışkan debili sistemler incelenmiştir. Ayrıca, örnek bir değişken soğutucu akışkan debili sistemin termodinamik analizi yapılmış, farklı çalışma koşullarında ve farklı soğutucu akışkanlar kullanılması durumlarında sistemin ekserji kayıpları karşılaştırılmıştır. Sistemin eş zamanlı ısıtma-soğutma yapma koşulunda en düşük soğutucu akışkan debisi gerçekleşirken, yalnız soğutma yapma koşulunda en yüksek soğutucu akışkan debisi gerçekleşmiştir. Entropi oluşumları ve ekserji kayıpları incelendiğinde, eş zamanlı ısıtma-soğutma yapma koşulunda en düşük entropi oluşumu ve ekserji kaybı meydana gelmiştir. Yalnız soğutma yapma koşulunda ise, en yüksek entropi oluşumu ve ekserji kaybı gerçekleşmiştir. Soğutucu akışkanlar karşılaştırıldığında ise, R404 soğutucu akışkanı kullanıldığında en düşük ekserji kaybı gerçekleşmiştir. En yüksek ekserji kaybı ise R410A soğutucu akışkanı kullanıldığında meydana gelmiştir. Bu çalışma ile konuya yönelik bilinçlenmenin arttırılması amaçlanmıştır., In this study, an overview of laws of thermodynamics and variable refrigerant flow systems have been investigated. Besides, thermodynamic analysis of a sample variable refrigerant flow system has been evaluated and exergy losses of different working conditions and different refrigerants has been compared. While minimum refrigerant mass flow rate has been occured in simultaneous heating-cooling working condition of the system, maximum refrigerant mass flow rate has been occured in only cooling working condition. When entropy generations and exergy losses analyzed, minimum entropy generations and exergy losses has been appeared in simultaneous heating-cooling working condition. Maximum entropy generations and exergy losses has been appeared in only cooling working condition. When refrigerants are compared, minimum exergy losses has been occured in using refigerant R404. Maximum exergy losses has been occured in using refigerant R410A. With this study, it has been intended to increase the awareness of the subject.

In this article, a design work which aimed to fulfill residental energy demand with benefiting from renewable energy sources was investigated. In order to have the green building features of this residental house; making the necessary heat insulation, using of electrical appliances in the low-energy class, utilization of materials that recycling and do not harm the environment have been paid attention. Fotovoltaic solar panels were used for electric power, ground source heat pumps and solar collectors were used for heating-cooling and hot water supply, rain water storage system was used for water. It was determined that on-grid system would be more economically advantageous so this system is used in design. It was determined the cost of providing energy saving and the systems were analysed for economical perspective. The systems which are used in green home were estimated payback periods and they were examined the reasonableness of this duration. The analysis concluded that the green home design has been right and it has been described as feasible of green house construction., Bu çalışmada, yenilenebilir enerji kaynaklarından yararlanılarak bir konutun enerji ihtiyacının karşılanması amacıyla yapılan tasarım çalışması incelenmiştir. Konutun, yeşil bina özelliklerini taşıyabilmesi için gereken ısı yalıtımının yapılmasına, düşük enerji sınıfında yer alan elektrikli ev aletlerinin kullanımına, geri dönüşümü olan ve çevreye zarar vermeyen malzemelerden faydalanılmasına dikkat edilmiştir. Elektrik enerjisi için fotovoltaik güneş panelleri, ısıtma-soğutma ve sıcak su eldesi için toprak kaynaklı ısı pompası ve güneş kollektörleri, kullanım suyu için ise yağmur suyu depolama sistemleri kullanılmıştır. Elektrik için şebekeye bağlı fotovoltaik sistemin ekonomik açıdan daha avantajlı olacağı belirlendiği için bu sistem, tasarımda kullanılmıştır. Sağlanan enerji tasarrufunun ortaya çıkardığı maliyet incelenmiş ve sistemler ekonomik yönden analiz edilmiştir. Yeşil evde kullanılan sistemlerin geri ödeme süreleri hesaplanmış ve bu sürelerin makul olup olmadığı incelenmiştir. Yapılan analiz neticesinde, yeşil evin tasarımının doğru olduğu ve yeşil ev kurulumunun uygulanabilir olduğu izah edilmiştir.

The Mutation-Minimization Method (MuMi) to study the local response of proteins to point mutations has been introduced here. The heat shock protein Hsp70 as the test system since it displays features that have been studied in great detail has been used here. It has many conserved residues, serves several different functions on each of its domains, and displays interdomain allostery. For the analysis of spatial arrangement of residues within the protein, the network properties of the wild type (WT) protein as well as its all single alanine residue mutants using MuMi has been investigated. The measures to express the amount of change from the WT structure upon mutation and compare these deviations to find potential critical sites have been proposed. The functional significance of the potential sites to the parameter that uncovers them has been mapped. It was found that sites directly involved in binding were sensitive to mutations and were characterized by large displacements. On the other hand, sites that steer large conformational changes typically had increased reachability upon alanine mutations occurring elsewhere in the protein. Finally, residues that control communication within and between domains reside on the largest number of paths connecting pairs of residues in the protein. Proteins 2015; 83:2077-2090. (c) 2015 Wiley Periodicals, Inc.

Human serum transferrin (hTf) transports ferric ions in the blood stream and inflamed mucosal surfaces with high affinity and delivers them to cells via receptor mediated endocytosis. A typical hTf is folded into two homologous lobes; each lobe is further divided into two similar sized domains. Three different crystal structures of hTf delineate large conformational changes involved in iron binding/dissociation. However, whether the release process follows the same trend at serum (~7.4) and endosomal (~5.6) pH remains unanswered. The specialized role of the two lobes and if communication between them leads to efficient and controlled release is also debated. Here, we study the dynamics of the full structure as well as the separate lobes in different closed, partially open, and open conformations under the nearly neutral pH conditions in the blood serum and the more acidic one in the endosome. The results corroborate experimental observations and underscore the distinguishing effect of pH on the dynamics of hTf. Furthermore, in a total of 2 {\mu}s molecular dynamics simulation of different forms of hTf, residue fluctuations elucidate the cross talk between the two lobes correlated by the peptide linker bridging the two lobes at serum pH, while their correlated motions is lost under endosomal conditions. At serum pH, the presence of even a single iron on either lobe leads C-lobe fluctuations to subside, making it the target for recognition by human cells or hostile bacteria seeking iron sequestration. The N-lobe, on the other hand, has a propensity to open, making iron readily available when needed at regions of serum pH. At endosomal pH, both lobes readily open, making irons available for delivery. The interplay between the relative mobility of the lobes renders efficient mechanism for the recognition and release of hTf at the cell surface, and therefore its recycling in the organism.

We investigate protonation as a possible route for triggering conformational change in proteins by focusing on the calmodulin (CaM) example. Two hundred nanosecond molecular dynamics (MD) simulations are performed on both the extended and compact forms of calcium loaded CaM. The stability of both structures is confirmed under prevailing conditions. Protonation of nine acidic residues with upshifted pK(a) values leads to a large conformational change in less than 100 ns. The structure attained is consistent with fluorescence resonance energy transfer experimental results as well as structures from an ensemble compatible with NMR data. Analysis of the MD trajectories summing up to one microsecond implies that the key events leading to the completion of the conformational change begins with an initial formation of a salt bridge between the N-lobe and the linker, followed by the bending of the C-lobe and the organization of a stabilizing hydrophobic patch between the lobes. We find that CaM utilizes its Ca2+ ions to harden/soften different regions so as to achieve various conformations. Thus, barrier crossing between extended and compact forms of CaM which is normally a rare event due to the repulsive electrostatic interactions between the two lobes is facilitated by protonation of high pK(a) residues. The results delineate how pH changes might be utilized in the cell to achieve different conformation-related functions.

The past decade has witnessed the development and success of coarse-grained network models of proteins for predicting many equilibrium properties related to collective modes of motion. Curiously, the results are usually robust towards the different cutoff distances used for constructing the residue networks from the knowledge of the experimental coordinates. In this study, we present a systematical study of network construction, and their effect on the predicted properties. Probing bond orientational order around each residue, we propose a natural partitioning of the interactions into an essential and a residual set. In this picture the robustness originates from the way with which new contacts are added so that an unusual local orientational order builds up. These residual interactions have a vanishingly small effect on the force vectors on each residue. The stability of the overall force balance then translates into the Hessian as small shifts in the slow modes of motion and an invariance of the corresponding eigenvectors. We introduce a rescaled version of the Hessian matrix and point out a link between the matrix Frobenius norm based on spectral stability arguments. A recipe for the optimal choice of partitioning the interactions into essential and residual components is prescribed. Implications for the study of biologically relevant properties of proteins are discussed with specific examples., Comment: 20 pages, 6 figures

It has been observed that the topology of the native state is an important determinant of protein folding kinetics and there is a significant correlation between folding rate and relative contact order (RCO) in two-state small single-domain proteins. However, as a pure topological property, RCO does not take into account residue interactions that also play an important role in folding kinetics. Using the inter-residue statistical contact potentials, we introduce weight into the residue network of contacts, and therefore define a weighted RCO. Using the weighted RCO, we can capture the folding kinetics of proteins having the same topology, but different sequence information. By constructing essential sub-networks based on the strength of the pairwise interactions, we are able to deduce the features of sequences redundant for folding events. We perform an analysis on 48 two-state proteins and the ultrafast-folding proteins, as well as mutants of the protein CI2, protein G, and protein L. Our results indicate that (i) both the weighted RCO of original residue network and that of essential sub-networks have significant correlations with the folding rate like RCO; (ii) the folding rate is critically dependent on the hydrophobic interactions for two-state folding; and (iii) the sub-networks distinguish the folding rate differences of the mutants and reveal the folding preferences of proteins., Comment: 18 pages, 6 figures

The past decade has witnessed the development and success of coarse-grained network models of proteins for predicting many equilibrium properties related to collective modes of motion. Curiously, the results are usually robust towards the different methodologies used for constructing the residue networks from knowledge of the experimental coordinates. We present a systematical study of network construction strategies, and their effect on the predicted properties. The analysis is based on the radial distribution function and the spectral dimensions of a large set of proteins as well as a newly defined quantity, the angular distribution function. By partitioning the interactions into an essential and a residual set, we show that the robustness originates from a large number of long-distance interactions belonging to the latter. These residuals have a vanishingly small effect on the force vectors on each residue. The overall force balance then translates into the Hessian as small shifts in the slow modes of motion and an invariance of the corresponding eigenvectors. Implications for the study of biologically relevant properties of proteins are discussed., Comment: 18 pages, 5 figures

Arthur's paradigm of the El Farol bar for modeling bounded rationality and inductive behavior is undertaken. The memory horizon available to the agents and the selection criteria they utilize for the prediction algorithm are the two essential variables identified to represent the heterogeneity of agent strategies. The latter is enriched by including various rewarding schemes during decision making. Though the external input of comfort level is not explicitly coded in the algorithm pool, it contributes to each agent's decision process. Playing with the essential variables, one can maneuver the overall outcome between the comfort level and the endogenously identified limiting state. Furthermore, we model the behavior of the agents through the use of an expression that scores the local attendance states available to the agents. It incorporates a single parameter that weighs the relative contributions that originate from the external and internal limiting factors. Solving this expression analytically as well as numerically using the Metropolis Monte-Carlo technique enables us to attribute statistical-thermodynamical meanings to the essential variables identified with the agent-based model, and to gain physical insight to the bounds observed in the behavior of the agents. The power of the analytical approach is validated by obtaining a one-to-one correspondence between the agent-based model and the analytical approach within a wide range of thresholds using a single parameter for a given selection criterion. The origin of discrepancies between the two models appearing at extreme thresholds is tracked to the shifts in the distributions of algorithm types actively utilized by the adaptive agents., Comment: 16 pages, 4 figures

We provide evidence that the energy landscapes of folded proteins do not shift with temperature, but the onset of functional dynamics is associated with its effective sampling. The motion of the backbone is described by three distinct regimes. One is associated with slow time scales of the activity along the envelope of the energy surface defining the folded protein. Another, with fast time scales, is due to activity along the pockets decorating the folded-state envelope. The intermediate regime emerges at temperatures where jumps between the pockets become possible, leading to an active protein., 13 pages with 4 figures; submitted to Phys. Rev. Lett