Collapse Time Research Articles

Collapse dynamics and Hilbert-space stochastic processes

Spontaneous collapse models of state vector reduction represent a possible solution to the quantum measurement problem. In the present paper we focus our attention on the Ghirardi–Rimini–Weber (GRW) theory and the corresponding continuous localisation models in the form of a Brownian-driven motion in Hilbert space. We consider experimental setups in which a single photon hits a beam splitter and is subsequently detected by photon detector(s), generating a superposition of photon-detector quantum states. Through a numerical approach we study the dependence of collapse times on the physical features of the superposition generated, including also the effect of a finite reaction time of the measuring apparatus. We find that collapse dynamics is sensitive to the number of detectors and the physical properties of the photon-detector quantum states superposition.

Rituals, Collapse, and Radical Transformation in Archaic States Edited by Joanne M.A. Murphy. London: Routledge 2021. Pp. 242. $160. ISBN 9780367230265 (cloth).

<i>Rituals, Collapse, and Radical Transformation in Archaic States</i> Edited by Joanne M.A. Murphy. London: Routledge 2021. Pp. 242. $160. ISBN 9780367230265 (cloth).

Kinetics of charged polymer collapse in poor solvents

Extensive molecular dynamics simulations, using simple charged polymer models, have been employed to probe the collapse kinetics of a single flexible polyelectrolyte (PE) chain under implicit poor solvent conditions. We investigate the role of the charged nature of PE chain (A), valency of counterions (Z) on the kinetics of such PE collapse. Our study shows that the collapse kinetics of charged polymers are significantly different from those of the neutral polymer and that the finite-size scaling behavior of PE collapse times does not follow the Rouse scaling as observed in the case of neutral polymers. The critical exponent for charged PE chains is found to be less than that of neutral polymers and also exhibits dependence on counterion valency. The coarsening of clusters along the PE chain suggests a multi-stage collapse and exhibits opposite behavior of exponents compared to neutral polymers: faster in the early stages and slower in the later stages of collapse.

Invariant submodel of rank 1 and two families of exact solutions of gas dynamics equations with an equation of state of the special form

In this article, the gas dynamics equations with an equation of state of the special form are considered.The equation of state is the pressure which is equal to the sum of two functions, with one being a function of a density, and the other one being a function of an entropy. The system of equations is invariant under the action of 12-parameter transformations group. For three-dimensional subalgebra 3.32 of the 12-dimensional Lie algebra invariants are calculated, an invariant submodel of rank 1 is constructed, and two families of exact solutions are obtained. The obtained solutions specify the motion of particles in space with a linear velocity field with inhomogeneous deformation. The first family of solutions has two moments of time of particles collapse. The second family of solutions has one moment of time of particles collapse on the plane. In the simplest case of second family of solutions, a surface consisting of particle trajectories is constructed.

Signatures of deconfined quark phases in binary neutron star mergers

We investigate the quark deconfinement phase transition in the context of binary neutron star (BNS) mergers. We treat hadronic matter using a Brueckner-Hartree-Fock quantum many-body approach and modern two-body and three-body nuclear interactions derived within chiral effective field theory. Quark matter is modeled using an extended version of the bag model. We combine these approaches to construct a new finite-temperature composition-dependent equation of state (EOS) with a first-order phase transition between hadrons and deconfined quarks. We perform numerical relativity simulations of BNS mergers with this new EOS and compare results obtained with or without the deconfinment phase transition. We find that deconfined quark production in a neutron star merger results from matter crossing the phase boundary over a wide range of temperatures and densities. The softening of the EOS due to the phase transition causes the merger remnants to be more compact and to collapse to a black hole at earlier times. The phase transition is imprinted on the postmerger gravitational wave (GW) signal duration, amplitude, and peak frequency. However, this imprint is only detectable for binaries with sufficiently long-lived remnants. Moreover, the phase transition does not result in significant deviations from quasiuniversal relations for the postmerger GW peak frequency. Consequently, the postmerger GW peak frequency alone is not sufficient to conclusively exclude or confirm the presence of a phase transition in a BNS merger. We also study the impact of the phase transition on dynamical ejecta, remnant accretion disk masses, $r$-process nucleosynthetic yields and associated electromagnetic counterparts. While there are differences in the electromagnetic counterparts and nucleosynthesis yields between the purely hadronic models and the models with phase transitions, these can be primarily ascribed to the difference in remnant collapse time between the two, so they are degenerate with other effects. An exception is the nonthermal afterglow caused by the interaction of the fastest component of the dynamical ejecta and the interstellar medium, which is systematically boosted in the binaries with phase transition as a consequence of the more violent merger they experience.

Prolonged Time of Lung Collapse Associated With Decreased Recovery of Functional Lung Following Palliative Radiotherapy

<h3>Purpose/Objective(s)</h3> Bronchial obstruction leading to lung collapse from primary lung or metastatic tumors is a common urgent consult to radiation oncology. Palliative chest radiotherapy (RT) can reduce the risk of progression of endobronchial or extrabronchial disease can be utilized alone or in combination with bronchial stenting to re-open existing collapsed lung. The ability to re-open collapsed lung following RT is likely multi-factorial with time since lung collapse long thought as an important predictor of reversibility. In this study, we sought to quantify the time-dependency of recovery of functional lung volume in patients with partial or complete lung collapse using a CT-based imaging metric highly correlated with lung function. <h3>Materials/Methods</h3> Patients with primary lung or metastatic tumors who received palliative chest RT due to segmental, lobar or whole lung collapse who additionally had follow-up CT imaging of the chest were identified from the institutional electronic health record. Total lung volumes on simulation and follow-up chest CTs were manually segmented using a commercially available software. To evaluate functional lung volume, a subthreshold function was applied to the image sets to determine volume of lung with attenuation of -950 to -701 HU. An estimate of time since initiation of lung collapse was determined by review of clinical records and imaging. <h3>Results</h3> A total of 25 evaluable patients were identified with non-small cell lung cancer (NSCLC) being the predominant histology observed (19/25, 76%). The median time of collapse before initiation of RT was 11 days (range = 3-57). The median dose received was 20 Gy in 5 fractions (range = 8 Gy/1 fx to 30 Gy/10 fx). The mean change in total lung volume was 1090 cc with mean change in functional lung volume of 1006 cc. Overall, a 92% increase in functional lung volume was observed following chest RT in this cohort. A linear trend toward decreasing recovery of functional lung was observed with more prolonged lung collapse (<i>P</i> = 0.074). Patients with estimated time of lung collapse of ≤14 days had higher mean recovery of functional lung (113%) compared with those with lung collapse > 14 days (55%) (<i>P</i> = 0.040). <h3>Conclusion</h3> Early initiation of palliative RT following lung collapse may lead to greater recovery of functional lung volume, which may confer a survival benefit/decrease hospitalization rates/improve fitness for systemic therapy. Improvements in targeted therapies are leading to more durable systemic responses potentially increasing the importance of timely chest RT for patients with existing or pending lung collapse as a bridge during acute thoracic events.

Simultaneous three‐translational‐axis vibration test that considers non‐Gaussianity

AbstractPackaging vibration tests are used to evaluate the vibration durability of packaged products by simulating transport vibration. Currently, the vertical Gaussian random vibration test is commonly used. However, in actual transport vibration environments, non‐Gaussian random vibration occurs along various axes simultaneously. To simulate actual transport vibration environments accurately and realistically, this study developed a simultaneous three‐translational‐axis vibration test that considers the three‐axis simultaneity of shock events, which is unique to non‐Gaussian vibration. In addition, to verify the effectiveness of the test, an experiment on the collapse of packaged products was performed by using three sets of vibration data (actual transport vibration data and vibration data with and without the three‐axis simultaneity of shock events), and the collapse time for each dataset was measured. The collapse time obtained using the vibration data with the three‐axis simultaneity of shock events was closer to the collapse time obtained using the actual transport vibration data than the collapse time obtained using the vibration data without the three‐axis simultaneity of shock events. Therefore, the simultaneous three‐translational‐axis vibration test that does not consider the three‐axis simultaneity of shock events may give different results from those obtained under actual transport vibration conditions. Therefore, to simulate actual transport vibration environments accurately and realistically, a simultaneous three‐translational‐axis vibration test that considers the three‐axis simultaneity of shock events should be performed.

Extended Hernquist–Springel formalism for cosmic star formation

ABSTRACT We present a revised and extended version of the analytical model for cosmic star formation originally given by Hernquist and Springel in 2003. The key assumption of this formalism is that star formation proceeds from cold gas, at a rate that is limited by an internal consumption time-scale at early times, or by the rate of generation of gas via cooling at late times. These processes are analysed as a function of the mass of dark matter haloes and integrated over the halo population. We modify this approach in two main ways to make it more general: (1) halo collapse times are included explicitly, so that the behaviour is physically reasonable at late times; (2) allowance is made for a mass-dependent baryon fraction in haloes, which incorporates feedback effects. This model reproduces the main features of the observed baryonic Tully–Fisher relationship, and is consistent with observational estimates of the baryon mass fraction in the intergalactic medium. With minimal adjustment of parameters, our approach reproduces the observed history of cosmic star formation within a factor of 2 over the redshift range of 0 &amp;lt; z &amp;lt; 10. This level of agreement is comparable to that achieved by state-of-the-art cosmological simulations. Our simplified apparatus has pedagogical value in illuminating the results of such detailed calculations, and also serves as a means for rapid approximate exploration of non-standard cosmological models.

Electron power absorption in micro atmospheric pressure plasma jets driven by tailored voltage waveforms in He/N2

In atmospheric pressure capacitively-coupled microplasma jets, voltage waveform tailoring (VWT) was demonstrated to provide ultimate control of the electron energy distribution function (EEDF), which allows us to enhance and adjust the generation of selected neutral species by controlling the electron power absorption dynamics. However, at the fundamental level, the physical origin of these effects of VWT remained unclear. Therefore, in this work, the electron power absorption dynamics is investigated in a He/N2 jet with a nitrogen concentration of 0.05% driven by a valleys voltage waveform at a base frequency of 13.56 MHz for different numbers of harmonics, using a self-consistent particle-in-cell simulation coupled with a spatio-temporally resolved analysis of the electron power absorption based on moments of the Boltzmann equation. Due to the local nature of the transport at atmospheric pressure, ohmic power absorption is dominant. Increasing the number of harmonics, due to the peculiar shape of the excitation waveform, the sheath collapse at the grounded electrode is shortened relative to the one at the powered electrode. As a consequence, and in order to ensure flux compensation of electrons and positive ions at this electrode, a high current is driven through the discharge at the time of this short sheath collapse. This current is primarily driven by a high ohmic electric field. Close to the grounded electrode, where the electron density is low and the electric field is therefore high, electrons are accelerated to high energies and strong ionization, as well as the formation of a local electron density maximum, are observed. This electron density maximum leads to a local ambipolar electric field that acts as an electric field reversal and accelerates electrons to even higher energies. These effects are understood in detail to fundamentally explain the unique potential of VWT for EEDF control in such plasmas.

Survival Times of Supramassive Neutron Stars Resulting from Binary Neutron Star Mergers

Abstract A binary neutron star (BNS) merger can lead to various outcomes, from indefinitely stable neutron stars, through supramassive neutron stars (SMNSs) or hypermassive neutron stars supported only temporarily against gravity, to black holes formed promptly after the merger. Up-to-date constraints on the BNS total mass and the neutron star equation of state suggest that a long-lived SMNS may form in ∼0.45–0.9 of BNS mergers. A maximally rotating SMNS needs to lose ∼(3–6) × 1052 erg of its rotational energy before it collapses, on a fraction of the spin-down timescale. An SMNS formation imprints on the electromagnetic counterparts to the BNS merger. However, a comparison with observations reveals tensions. First, the distribution of collapse times is too wide and that of released energies too narrow (and the energy itself too large) to explain the observed distributions of internal X-ray plateaus, invoked as evidence for SMNS-powered energy injection. Second, the immense energy injection into the blast wave should lead to extremely bright radio transients, which previous studies found to be inconsistent with deep radio observations of short gamma-ray bursts (GRBs). Furthermore, we show that upcoming all-sky radio surveys will constrain the extracted energy distribution, independently of a GRB jet formation. Our results can be self-consistently understood, provided that most BNS merger remnants collapse shortly after formation (even if their masses are low enough to allow for SMNS formation). This naturally occurs if the remnant retains half or less of its initial energy by the time it enters solid-body rotation.

Experimental study on the mesoscale causes of the effect of sediment size and concentration on material cavitation erosion in sandy water

The cavitation erosion of materials in sandy water is a very important topic in water conservancy and industrial production. In this paper, an ultrasonic vibration cavitation apparatus and underwater low-voltage electric discharge device are applied to investigate the erosion characteristics of 6063 aluminium specimens in sandy water with different sediment sizes and concentrations and the underlying mesoscale damage mechanism. The results show that the specimen damage gradually increases as the mean sand particle size increases. When the mean sand particle size is less than 0.120 mm, the resulting damage is lower than that in pure water. When the sand concentration is less than 10 kg/m3, the resulting damage is not very different from that in pure water. As the sediment concentration in the sand-water mixture increases, the influence of the sand particles on cavitation gradually increases. The bubble-particle interaction experiments reveal that the cavitation bubbles that interact with multiple small spherical particles show obvious non-spherical morphology and prolong the collapse time during the first collapse phase and reduce the collapse strength. The results of the bubble-particle interaction experiments verify the erosion characteristics obtained from the ultrasonic vibration cavitation test, which is significant for elucidating the damage mechanics of specimens in sandy water.

Supplying angular momentum to the jittering jets explosion mechanism using inner convection layers

ABSTRACT We conduct one-dimensional stellar evolution simulations in the mass range 13–20 M⊙ to late core collapse times and find that an inner vigorous convective zone with large specific angular momentum fluctuations appears at the edge of the iron core during the collapse. The compression of this zone during the collapse increases the luminosity there and the convective velocities, such that the specific angular momentum fluctuations are of the order of $j_{\rm conv} \simeq 5 \times 10^{15} {~\rm cm}^2 {~\rm s}^{-1}$. If we consider that three-dimensional simulations show convective velocities that are three to four times larger than what the mixing length theory gives, and that the spiral standing accretion shock instability in the post-shock region of the stalled shock at a radius of ${\simeq}100 {~\rm km}$ amplifies perturbations, we conclude that the fluctuations that develop during core collapse are likely to lead to stochastic (intermittent) accretion discs around the newly born neutron star. In reaching this conclusion, we also make two basic assumptions with uncertainties that we discuss. Such intermittent discs can launch jets that explode the star in the frame of the jittering jets explosion mechanism.

Deflation and collapse of air-supported membrane structures

Air-supported membrane structures are widely used in stadiums, malls, and museums. The stiffness and shape of such structures are dependent on the pressure difference between the indoor and outdoor environments. As the leakage of indoor air may lead to the collapse of the structure, it is necessary to study the deflation deformation process, including the properties that can cause air-supported membrane structures to collapse. In this study, a rectangular air-supported membrane structure is fabricated using a PVC-coated polyester fabric membrane with dimensions of 38 m × 20 m × 7 m, and a leakage experiment is performed. The relationship between the initial leakage area and the pressure difference is obtained, and a new algorithm to determine the equivalent initial leakage rate is proposed. A collapse test is then conducted, with results illustrating that there are two distinct phases of collapse. There is a quick drop in the pressure difference in the first phase, whereas the pressure difference declines rather slowly in the second phase. Computational formulae for collapse and escape times are established, and finally, a quasi-equilibrium status-based algorithm to determine the collapse time of air-supported structures is proposed. Using the new algorithm, several main parameters that influence the collapse of air-supported structures are studied, including the cables, initial pressure, and leakage area. Results show that the initial pressure has a minimal effect on the collapse of structures, while excessive cables accelerate the process of collapse.

Effects of surface tension on the dynamics of a single micro bubble near a rigid wall in an ultrasonic field

Acoustic cavitation is a very important hydrodynamic phenomenon, and is often implicated in a myriad of industrial, medical, and daily living applications. In these applications, the effect mechanism of liquid surface tension on improving the efficiency of acoustic cavitation is a crucial concern for researchers. In this study, the effects of liquid surface tension on the dynamics of an ultrasonic driven bubble near a rigid wall, which could be the main mechanism of efficiency improvement in the applications of acoustic cavitation, were investigated at the microscale level. A synchronous high-speed microscopic imaging method was used to clearly record the temporary evolution of single acoustic cavitation bubble in the liquids with different surface tension. Meanwhile, the bubble dynamic characteristics, such as the position and time of bubble collapse, the size and stability of the bubbles, the speed of bubble boundaries and the micro-jets, were analyzed and compared. In the case of the single bubbles near a rigid wall, it was found that low surface tension reduces the stability of the bubbles in the liquid medium. Meanwhile, the bubbles collapse earlier and farther from the rigid wall in the liquids with lower surface tension. In addition, the surface tension has no significant influence on the speed of the first micro-jet, but it can substantially increase the speed of second and the third micro-jets after the first collapse of the bubble. These effects of liquid surface tension on the bubble dynamics can explain the mechanism of surfactants in numerous fields of acoustic cavitation for facilitating its optimization and application.

Numerical investigation into effects of gas concentration and bubble collapse on tip vortex cavitation noise of NACA16-020 wing

In this study, the effects of gas concentration and bubble collapse on tip vortex cavitation noise of NACA16-020 wings are investigated using coupled Eulerian-Lagrangian method based on sequential application of Reynolds averaged Navier-Stokes (RANS) solver, bubble dynamics model and acoustic analogy. The bubble dynamics model used in the preceding study (Ku et al., 2020) is modified by including the gas pressure terms and the bubble collapse model, which depends on the timing and threshold of bubble collapse, the number, initial radius and location of divided bubbles. The validity of the modified bubble dynamics model is confirmed through its application to a benchmark problem where single bubble is triggered by laser. Then, the coupled Eulerian-Lagrangian method based on the modified bubble dynamic model is applied for the prediction of tip-vortex cavitation noise of NACA16-020 wing. The predicted results of the tip vortex pattern and acoustic pressure spectrum are compared with the measured results, which shows closer agreements between two results than those in the previous study.

Disproportionate collapse of steel-framed gravity buildings under travelling fires

Observations from realistic fires have revealed that a fire tends to “travel” across the floors rather than burning simultaneously for the duration. However, the collapse mechanism and mitigation measures of structures under travelling fires are still not well understood. This paper investigates the disproportionate collapse behaviour of three-dimensional steel-framed gravity buildings subjected to travelling fires. The effect of fire curves (burning rate) and fire spreading speeds on the collapse behaviour is first studied. The effectiveness of using fire protections and bracing systems in preventing collapse is examined. It is found that the duration of the heating phase has a great effect on whether a building collapses or not, and the building may collapse during the cooling phase. A “long-cool” fire curve (slow burnig rate) is more dangerous than mild (average burning rate) and “short-hot” fire curves (fast burning rate) since the former causes a higher temperature in the structure. The fire travelling speed significantly affects the failure sequence of columns, range of damage and collapse mode of structures. For the structure analysed, a slow travelling fire (e.g. 2.5 mm/s) may lead to a partial collapse mode confined around the fire-affected region, but a global collapse in a wider range may occur in a fast travelling fire (e.g. 10 mm/s). A higher level of fire protection may prevent the collapse of structures, but may also lead to collapse in the cooling phase due to the delayed increment of temperatures in the heated members. The collapse time of a protected structure under a travelling fire is longer than the fire-resistance rating of its components (up to 130 min). Application of bracing systems (horizontal, vertical or combined) can prevent collapse of structures under a slow travelling fire, but not for a fast travelling fire. It is recommended to consider the possible fire scenarios when determining the fire-resistance rating, and increase the fire-resistance rating of components to 3 h to prevent collapse under a travelling fire with a “long-cool” fire curve. The beam-to-column connections should possess a sufficient tension and compression resistance, which may be equal to 100% and 50% of the yielding capacity of beams, respectively.

Seismic Analysis of Multi Storey Building Using Strong Column Weak Beam Ratio (SCWB) in Different Zones of India

An earthquake structures are mandatory to avoid significant damages (i.e., collapse) and aims that structure withstand a major earthquake without collapse. The design approach adopted is to ensure that the columns of the structure more capable to resist moments than beam; to avoid progressive collapse of structure due to failure of columns in lower level; it is necessary the columns have stronger than beams (strong column weak beam). The concept of SCWB is to ensure that plastic hinge formed in the beam not in the column; this help in dissipating the more energy along with providing ductility to the structure. If the plastic hinge is formed on the both ends of column then, the column is not able to spread the plasticity and collapse which are leads to global failure. The failure modes in all past earthquake is exactly opposite i.e, strong beam weak column; and comes to sway mechanism and fails to collapse. For this it is foreseen that the values of ratio of Mc/Mb (ratio of sum of ultimate moment of resistance of columns to sum of ultimate moment of resistance of beam) in the beam-column joint are stated by many design codes and the values are different ranging from 1.2,1.3,1.4,1.5 to 2, etc. Another effect of ratio Ic/Ib (ratio of moment of inertia of column to moment of inertia of beam) have been studied but the exact meeting of SCWB behaviour in the structures at the time of collapse not stated clearly. The Mc/Mb and Ic/Ib ratio are very important to prevent damage in the structure under seismic action. In the present work, attempts are made to achieve exact ratio of exact strong column weak beam. In this study, the combined effect of two ratio (Mc/Mb, Ic/Ib) simultaneously investigated in different zones of India to find out exact SCWB ratio’s value for to meet the SCWB behaviour. Different numerical examples are presented of combine ratios (Mc/Mb,Ic/Ib) and pushover analysis is performed on each ratio’s. The result of the investigation highlighted on the objective that is to find exact SCWB ratio value considering the parameter like target displacement, ductility ratio, hinge response etc.

Energy absorption characteristic of bionic lightweight protective structure with curved tubes under impact loading

Reinforcing and toughening materials with light quality in engineered structures remains a challenge. In the biological tissues of numerous animal and plant species, efficient strategies have evolved to construct structures that have excellent mechanical properties. As a kind of biological structure with high-strength fiber, beetle elytron not only provides protection function for beetles, but also makes beetles light enough to obtain good flight ability. Because of these advantages of inner fibrous structure of elytron, the bionic investigation of beetle elytron has gradually become one of the research focuses in civil engineering and automobile anti-collision fields. In the present work, the honeycomb and tubes composed of fiber in the beetle elytra was analyzed, and a variety of bionic thin-walled honeycomb structures with curved hollow tubes were designed and modeled. The energy absorption ability of the bionic honeycomb structures with different types of tubes under impact loading were calculated by finite element software. The internal energy values and collapse processes of bionic structures were compared and analyzed at different crushing displacements. The parameter study, including wall thickness and impact angle, was carried out in the collapse time range from 0 ms to 8 ms. These results could be applied in developing crush-resistant materials in the field of automotive passive safety.

The evolution of Cuban medical diplomacy

The author examines the evolution of Cuban medical diplomacy under the governments of Raul Castro and Miguel Diaz-Canel. The author shows that the essence of the Cuban national health system, which developed after the 1959 Revolution, is its accessibility. At the time of collapse of the socialist bloc, the Cuban government managed to maintain and surpass the achieved level of development of medicine. The presence of a large number of medical specialists allows the socialist government of Cuba to organize cooperation with dozens of states around the world. Under the leadership of Castro, the export of medical goods and services has become the main source of foreign exchange earnings and a driver of economic growth, and medical diplomacy has become an important tool of soft power, which is used to form an attractive image of the state among the world community. In doing so, the government combines pragmatism, increasing the cost-effectiveness of the programs, and altruism, providing gratuitous aid to the countries most in need. The main difficulty in developing this direction in Cuba’s foreign policy is associated with the North American embargo. In 2018, the US government launched a large-scale campaign to discredit Cuban medical internationalism. This policy aims to further restrict already limited access to essential resources. The country was also negatively affected by the ‘right turn’ in the region: the neoliberal governments of several countries refused to continue medical cooperation with Cuba. At the same time, the trends of recent years indicate an imminent repetition of the shift to the left, which in the future can significantly strengthen the Cuban positions in the region. In addition, the coronavirus pandemic showed that the world community needs a rapid medical response force with Cuban missions serving as a basis thereof.

Rethinking of Turkey’s Geopolitics together with Eastern Mediterranean. Turkish Perspective

In the studies carried out within the scope of geopolitical discipline, the expression "geography is destiny" is frequently used and it is claimed that geography has unchangeable, irreversible qualities and the policies implemented are shaped through this assumption. This assumption ignores the humanitarian interventions over the geography and makes it difficult to understand the results produced by these interventions at both regional and global level. Similarly, the dynamic nature of international relations reveals new actors in the international system in times of bounce and collapse, and the borders that expand or narrow with each transformation can differentiate the geopolitical view with new sovereign countries. In the historical process, transportation accessibility, trade, search for raw materials, security and alliance relations have caused the same geography to be interpreted differently in different periods. This situation also applies to the geography of Turkey had been the homeland of empires. The developments in the Middle East over the past two decades has created a sensitivity in the relations between Turkey and the West, especially the United States. Competing interests with the EU and the US in the Middle East and the Eastern Mediterranean, has necessitated a reassessment of Turkey's geography.