Electronic and Lattice Dynamical Properties of Ti2SiB MAX Phase

The structural, electronic, mechanic, vibrational and thermodynamic properties of Ti2SiB which is a hypothetical MAX phase compound, have been investigated using density functional theory calculations. The structural optimization of Ti2SiB has been performed and the results have been compared with Ti2SiC, Ti2SiN, and Ti2AlB that are studied in the literature. Then the band structure and corresponding partial density of states are computed. In addition, charge density and Bader charge analysis have been performed. The elastic constants have been obtained, then the secondary results such as bulk modulus, shear modulus, Youngs modulus, Poissons ratio, and Vickers Hardness of polycrystalline aggregates have been derived, and the relevant mechanical properties have been discussed. Moreover, the elastic anisotropy has been visualized in detail by plotting the directional dependence of compressibility, Poisson ratio, Youngs and Shear moduli. Furthermore, the phonon dispersion curves as well as corresponding phonon PDOS, and thermodynamical properties such as free energy, entropy and heat capacity have been computed and the obtained results have been discussed in detail. This study provides the first considerations of Ti2SiB that could have a potential application in nuclear industry

Fine-Grained Object Recognition and Zero-Shot Learning in Remote Sensing Imagery

Fine-grained object recognition that aims to identify the type of an object among a large number of subcategories is an emerging application with the increasing resolution that exposes new details in image data. Traditional fully supervised algorithms fail to handle this problem where there is low between-class variance and high within-class variance for the classes of interest with small sample sizes. We study an even more extreme scenario named zero-shot learning (ZSL) in which no training example exists for some of the classes. ZSL aims to build a recognition model for new unseen categories by relating them to seen classes that were previously learned. We establish this relation by learning a compatibility function between image features extracted via a convolutional neural network and auxiliary information that describes the semantics of the classes of interest by using training samples from the seen classes. Then, we show how knowledge transfer can be performed for the unseen classes by maximizing this function during inference. We introduce a new data set that contains 40 different types of street trees in 1-ft spatial resolution aerial data, and evaluate the performance of this model with manually annotated attributes, a natural language model, and a scientific taxonomy as auxiliary information. The experiments show that the proposed model achieves 14.3% recognition accuracy for the classes with no training examples, which is significantly better than a random guess accuracy of 6.3% for 16 test classes, and three other ZSL algorithms.Comment: G. Sumbul, R. G. Cinbis, S. Aksoy, "Fine-Grained Object Recognition and Zero-Shot Learning in Remote Sensing Imagery", IEEE Transactions on Geoscience and Remote Sensing (TGRS), in press, 201

Enabling a Sustainable Economy through Energy Systems Modeling: Solar-centric, Efficient, Integrated and Continuous Process Synthesis and Optimization

The expected increase in food, energy and water demand due to increase in population and change in consumption habits in conjunction with diminishing fossil fuel reserves and increasing greenhouse gas emissions urge the development and implementation of alternative energy conversion techniques using renewable energy for a sustainable economy. Among renewable energy sources, solar energy is prominent due to its abundance. A sustainable economy can be created by producing building blocks foundational to meeting all basic human needs of daily existence. However, intermittencies and limitations on land area dedicated to harness solar energy are the major obstacles on widespread implementation of solar energy conversion technologies. To address these challenges this dissertation has identified energy efficient, synergistically integrated, continuously operable process designs and process synthesis methods for harnessing renewable energy sources for various end uses. Hydricity, a paradigm that proposes synergistic coproduction of solar thermal power and hydrogen, is introduced. The Hydricity concept is realized by judiciously integrating solar water power (SWP) cycle, solar thermal hydrogen production techniques, and turbine-based hydrogen power cycle and by suitably improving each one for compatibility and beneficial interaction. When the proposed integrated process is operated in a standalone, solely power production mode, the resulting solar water power cycle can generate electricity with unprecedented efficiencies of 40 - 46%. Similarly, in the standalone hydrogen mode, pressurized hydrogen is produced at efficiencies approaching ~50%. In the coproduction mode, the coproduced hydrogen is stored for uninterrupted solar power production. When sunlight is unavailable, the stored hydrogen is used in a turbine-based hydrogen water power (H2WP) cycle with the calculated hydrogen-to-electricity efficiency of 65 - 70%, which is comparable to fuel cell efficiencies. The H2WP cycle uses much of the same equipment as the solar water power cycle, reducing capital outlays. The overall sun-to electricity efficiency of the hydricity process, averaged over a 24 hour cycle, is shown to approach ~35%, which is nearly the efficiency attained by using the best multijunction photovoltaic cells along with batteries. In comparison, our proposed process has the following advantages: (i) It stores energy thermochemically with a two- to threefold higher density than batteries, (ii) coproduced hydrogen has alternate uses in transportation/chemical/petrochemical industries, and (iii) unlike in the case of batteries, the stored energy does not discharge over time, and the storage medium does not degrade with repeated uses. For uninterrupted renewable power supply, carbon storage cycles (CSC), which involve cyclic transformation of carbon atoms between carbon dioxide and carbon fuel are studied. CSC has the potential to achieve high storage efficiency (~54% - 59%) for GWh-level energy storage with much reduced storage volumes compared to other options. Detailed process simulations of DME storage cycle is performed, which resulted in ~57% storage efficiency. The increasing need of fresh water is met by integration strategies of multi stage flash (MSF) desalination process with solar thermal power and hydrogen production processes are established. In addition to integration with SWP cycles and modified SWP cycles, high pressure desalination alternatives are also designed and analyzed. To continuously produce fresh water, MSF desalination process is integrated with hydrogen and electricity coproduction process whereby stored hydrogen is converted to electricity by modified H2WP cycle while coproducing fresh water when solar energy is not available. To supply food, energy and water (FEW) demand for a full earth, the potential of a novel approach for the utilization of the entire solar spectrum by directing solar photons to maximize FEW production from a land area is studied. The proposed solar spectrum unbundling FEW systems (SUFEWS) can enhance quality of life while reducing the overall environmental impact of meeting these needs. SUFEWS implementation on a relatively small portion of agricultural land area can supply the entire electricity and fresh water demand without reducing the food production capacity. Towards reducing the CO2 emissions associated with the transportation sector, synergistic carbon and energy efficient process designs for integrated biomass and natural gas (NG) to liquid fuel conversion is synthesized by formulating and solving a process superstructure optimization problem. The solution of the Mixed Integer Nonlinear Programming (MINLP) model identified the optimal process configurations that are capable of producing ~15% more liquid fuel output than the combined fuel output of individual standalone processes converting the same amount of biomass and NG. This synergy originates from synthesizing additional liquid fuel by combining the residual biomass carbon with the excess hydrogen per carbon available from the NG feed

An Analysis of Factors Affecting the Effective Use of Knowledge Management in Counter Improvised Explosive Device (C-IED) Operations

This dissertation investigates factors that influence effective use of Knowledge Management (KM) in Counter Improvised Explosive Device (C-IED) operations in the military. The study suggests that effective KM program is determined by the interaction of three organizational capabilities: knowledge infrastructure, knowledge process, and leadership orientation. A self-administrated survey was conducted on 300 NATO staff officers who have served in C-IED environments. A structural equation modeling technique was used to test a set of hypotheses using 118 completed responses collected from the survey. The results suggest that out of the 11 constructs within the model; two are rated as \u27attribute needs immediate attention\u27 (i.e. Culture and Traditional Leadership Capability), eight are rated as \u27attribute needs further enhancement\u27 (i.e. Overall Organizational Capability, Knowledge Process, Knowledge Infrastructure, Acquisition, Transfer, Application, Structure and Transformational Leadership Capability) and one is rated as \u27attribute runs satisfactorily\u27 (i.e. Technology). Additionally, the study identified a set of factors that military leaders and commanders should consider before undertaking any KM programs. The results of this research have particular value to engineering management researchers and practitioners operating in military domains because it proposes, empirically tests and justifies a conceptual model that explains KM in C-IED operations in the US military

Increasing chemosensitivity of chronic myeloid leukemia cells to dasatinib by targeting bioactive sphingolipids

Thesis (Master)--Izmir Institute of Technology, Molecular Biology and Genetics, Izmir, 2010Includes bibliographical references (leaves: 56-68)Text in English; Abstract: Turkish and Englishxii, 68 leavesSphingolipids are bioeffector molecules which control various aspects of cell growth, proliferation, apoptosis, senescence, and drug resistance. Ceramides, the central molecule of sphingolipid metabolism, are inducer of apoptosis and inhibitors of proliferation. Sphingosine-1-phosphate (S1P) and glucosyl ceramide, converted from ceramides by sphingosine kinase-1 (SK1) and glucosyl ceramide synthase (GCS) enzymes respectively, inhibit apoptosis, induce cell proliferation and develop resistance to chemotherapeutic drugs. In this study, we examined the therapeutic potentials of bioactive sphingolipids in chronic myeloid leukemia (CML) by itself and in combination with dasatinib in addition to investigate the roles of ceramide metabolising genes in dasatinib induced apoptosis. Our results demonstrated that application of ceramide analogs and inhibitors of ceramide clearance enzymes decreased cell proliferation and induced apoptosis. On the other hand, targeting bioactive sphingolipids towards generation/accumulation of ceramides increased apoptotic effects of dasatinib synergistically. It was also shown for the first time by this study that dasatinib induces apoptosis through downregulating expression levels of GCS, and SK-1 genes and upregulating expression levels of LASS1, -2, -4, -5, and -6 in K562 cells. However, in Meg-01 cells, dasatinib downregulates expression levels of apoptotic LASS genes. Increasing endogenous ceramides through exogenous ceramide analogues or mimetics and decreasing prosurvival lipids, S1P and GC, can open the way of more effective treatment of CML

Effects of 8-Week Core Exercises on Free Style Swimming Performance of Female Swimmers Aged 9-12

With this study, it is aimed to review the effects of 8-week core exercises, which are scheduled before the routine exercises, on changes over certain physical and motoric attributes and freestyle swimming performance of female athletes of the youngest age group, which is 9-12. For the study, a group of 12 female licensed swimmers who had a swimming background of 3 years in city of Van is chosen to be core exercise group (CEG) and set as experimental group. And 12 female swimmers are chosen to be in control group. The athletes are scheduled to perform regular swimming exercises for competition, five days a week and for approximately 90 minutes per day. In addition to control group, CEG is scheduled to perform 20 minutes of low intensity, fixed duration and repetitive core exercises before every routine exercise for 8 weeks. Chosen measurements are obtained from the athletes both at the beginning and after 8 weeks and the change between pretest and posttest values is evaluated. For the statistical data analysis, non-parametric tests of Wilcoxon and Mann Whitney U tests are used. As a results of the study, the group of swimmers aged 9-12 who underwent 8 weeks of low intensity core exercises showed differences compared to pretest and posttest values of control group, even though not statistically significant (p>0,05). As a result, compared to the control group, a 1-2 seconds of decrease – especially when it is a very important amount for this sport – in 25 m and 50 m free style swimming ranks is attributed to the effect of core exercises, and it is reckoned that low intensity core exercises may positively affect the free style swimming performance of female swimmers aged 9-12

The Evolution of Turkish-EU Relations and an Evaluation of Its Future

Turkey's relations with EU (EEC, EC) is analyzed, not from a perspective of chronologicallisting of events, but from the perspective of determining the changes over time in opinions of major groups and political parties about the full membership of Turkey into the EU. In Turkey, until 1980s, center-right groups and political parties were generally in favor of developing the Turkish-EECrelations, while center-left, as well as radical left and radical right were against it. In the 1990s and2000s, center-left groups and political parties changed their perspective and also worked effectivelyfor the development of Turkish-EU relations. During the earlier decades of associate membership,generally the EEC (except Greece) was more open to Turkey's full membership into the EEC.However, the full membership was seen to be dependent on time due to concerns about the relativeeconomic backwardness of Turkey. But since 1990s and 2000s, as the EU both enlarged and alsodeepened, opposition in the EU to Turkey's full membership increased, mainly due to criticisms aboutthe lack of human rights and democracy in Turkey besides economic problems. Over time, the centerright groups and political parties in the EU became skeptical about Turkey's full membership because they believe that Turkey, a Muslim country, has a different, non-European mentality (religion andculture) and hence, would not fit into the EU. The EU's center-left, as well as Greens and Liberals,however, think that as long as Turkey would meet the political and economic criteria of the EU shewould be accepted as a full EU member, irrespective of her mentality. In Turkey, on the other hand,many intellectuals believe that the EU was and still is not fair and objective towards Turkey in theCyprus issue, as well as in the PKK terror, and also in the 1915 Armenian problem. Thus, thewillingness in Turkey to join the EU as a full member has decreased, as well, and as a result, Turkeyslacked her efforts at reform and instead strengthened her economic and political ties with Muslim countries. Therefore, even though almost half a century has passed since the 1963 Ankara Agreement, which established Turkey's associate membership open to full membership into the EEC, Turkey's full membership into the EU looks more difficult than ever and pushed further into the far future, if not lost completely