Coal deposits of Turkey: properties and importance on energy demand

Κατά τις τελευταίες δυο δεκαετίες η παραγωγή και η κατανάλωση ηλεκτρικής ενέργειας στην Τουρκία αυξήθηκε με γρήγορους ρυθμούς. Περίπου 80% της παραγόμενης ηλεκτρικής ενέργειας προέρχεται από συμβατικά καύσιμα, όπως εισαγόμενο φυσικό αέριο και πετρέλαιο, αλλά και εγχώριους γαιάνθρακες. Καθώς όμως η σύγχρονη ενεργειακή πολιτική προσανατολίζεται σε μείωση της εξάρτησης από εισαγωγές καυσίμων, ο εγχώριος γαιάνθρακας, ιδιαίτερα ο χαμηλού βαθμού ενανθράκωσης, αποκτά σημασία για τη χώρα. Οι τελευταίες έρευνες ανεβάζουν τα αποθέματα σε ~13 Gt, με τον λιγνίτη και τον υποβιτουμενιούχο γαιάνθρακα να κυριαρχούν. Κοιτάσματα γαιανθράκων, που σχηματίστηκαν κάτω από διάφορες συνθήκες και σε διάφορες γεωλογικές περιόδους, υπάρχουν σε όλη τη χώρα. Τα σημαντικότερα είναι Τριτογενούς ηλικίας, με αυτά του Νεογενούς να είναι τα καταλληλότερα για ηλεκτροπαραγωγή εξαιτίας των μεγάλων αποθεμάτων παρά την υψηλή τέφρα και τη χαμηλή θερμαντική ικανότητα. Με την εφαρμογή ορθολογικής εκμετάλλευσης και καταλλήλων μεθόδων εμπλουτισμού ο γαιάνθρακας θα διαδραματίσει στο μέλλον σημαντικό ρόλο στην ενεργειακή τροφοδοσία της Τουρκίας.In the last two decades electricity generation and consumption in Turkey was increasing steadily. Around 80% of the electricity generated is derived from fossil fuels such as imported natural gas and oil, and domestic coal. As the energy policy now is focusing on reducing the dependency on imported fuels, coal, particularly this of low-rank, is becoming important for the country. Latest explorations showed that total coal reserves of Turkey reach to 13 Gt with low-rank coals (i.e. lignite and sub-bituminous) being dominant. Coal deposits, formed under various conditions and in various geological times, are widely spread over the territory. The most significant deposits are of Tertiary, especially Neogene age. Neogene coals are most appropriate for combustion in the thermal power plants due to the high total reserves despite the high ash yields and the low calorific values. We imply that applying reasonable exploitation planning and appropriate washing techniques, coal will play a key role in future energy supply of the country

Precision spectroscopy with two correlated atoms

We discuss techniques that allow for long coherence times in laser spectroscopy experiments with two trapped ions. We show that for this purpose not only entangled ions prepared in decoherence-free subspaces can be used but also a pair of ions that are not entangled but subject to the same kind of phase noise. We apply this technique to a measurement of the electric quadrupole moment of the 3d D5/2 state of 40Ca+ and to a measurement of the linewidth of an ultrastable laser exciting a pair of 40Ca+ ions

Diffusion Resonances in Action Space for an Atom Optics Kicked Rotor with Decoherence

We numerically investigate momentum diffusion rates for the pulse kicked rotor across the quantum to classical transition as the dynamics are made more macroscopic by increasing the total system action. For initial and late time rates we observe an enhanced diffusion peak which shifts and scales with changing kick strength, and we also observe distinctive peaks around quantum resonances. Our investigations take place in the context of a system of ultracold atoms which is coupled to its environment via spontaneous emission decoherence, and the effects should be realisable in ongoing experiments.Comment: 4 Pages, RevTeX 4, 5 Figures. Updated Figures, Minor Changes to text, Corrected Reference

Quantum control, quantum information processing, and quantum-limited metrology with trapped ions

We briefly discuss recent experiments on quantum information processing using trapped ions at NIST. A central theme of this work has been to increase our capabilities in terms of quantum computing protocols, but we have also applied the same concepts to improved metrology, particularly in the area of frequency standards and atomic clocks. Such work may eventually shed light on more fundamental issues, such as the quantum measurement problem.Comment: Proceedings of the International Conference on Laser Spectroscopy (ICOLS), 10 pages, 5 figure

Testing the stability of fundamental constants with the 199Hg+ single-ion optical clock

Over a two-year duration, we have compared the frequency of the 199Hg+ 5d106s 2S 1/2 (F=0) 5d9 6s2 2D 5/2 (F=2) electric-quadrupole transition at 282 nm with the frequency of the ground-state hyperfine splitting in neutral 133Cs. These measurements show that any fractional time variation of the ratio nu(Cs)/nu(Hg) between the two frequencies is smaller than +/- 7 10^-15 / yr (1 sigma uncertainty). According to recent atomic structure calculations, this sets an upper limit to a possible fractional time variation of g(Cs) m_e / m_p alpha^6.0 at the same level.Comment: 4 pages with 3 figures. RevTeX 4, Submitted to Phys. Rev. Let

'Designer atoms' for quantum metrology

Entanglement is recognized as a key resource for quantum computation and quantum cryptography. For quantum metrology, the use of entangled states has been discussed and demonstrated as a means of improving the signal-to-noise ratio. In addition, entangled states have been used in experiments for efficient quantum state detection and for the measurement of scattering lengths. In quantum information processing, manipulation of individual quantum bits allows for the tailored design of specific states that are insensitive to the detrimental influences of an environment. Such 'decoherence-free subspaces' protect quantum information and yield significantly enhanced coherence times. Here we use a decoherence-free subspace with specifically designed entangled states to demonstrate precision spectroscopy of a pair of trapped Ca+ ions; we obtain the electric quadrupole moment, which is of use for frequency standard applications. We find that entangled states are not only useful for enhancing the signal-to-noise ratio in frequency measurements - a suitably designed pair of atoms also allows clock measurements in the presence of strong technical noise. Our technique makes explicit use of non-locality as an entanglement property and provides an approach for 'designed' quantum metrology

Nanofabrication by magnetic focusing of supersonic beams

We present a new method for nanoscale atom lithography. We propose the use of a supersonic atomic beam, which provides an extremely high-brightness and cold source of fast atoms. The atoms are to be focused onto a substrate using a thin magnetic film, into which apertures with widths on the order of 100 nm have been etched. Focused spot sizes near or below 10 nm, with focal lengths on the order of 10 microns, are predicted. This scheme is applicable both to precision patterning of surfaces with metastable atomic beams and to direct deposition of material.Comment: 4 pages, 3 figure

Squeezing of Atoms in a Pulsed Optical Lattice

We study the process of squeezing of an ensemble of cold atoms in a pulsed optical lattice. The problem is treated both classically and quantum-mechanically under various thermal conditions. We show that a dramatic compression of the atomic density near the minima of the optical potential can be achieved with a proper pulsing of the lattice. Several strategies leading to the enhanced atomic squeezing are suggested, compared and optimized.Comment: Latex, 9 pages, 10 figures, submitted to PR

Influence of migrant background on patient preference and expectations in breast and gynecological malignancies (NOGGO-expression V study): results of a prospective multicentre study in 606 patients in Germany

Background: An effective cross-cultural doctor-patient communication is vital for health literacy and patient compliance. Building a good relationship with medical staff is also relevant for the treatment decision-making process for cancer patients. Studies about the role of a specific migrant background regarding patient preferences and expectations are lacking. We therefore conducted a multicentre prospective survey to explore the needs and preferences of patients with a migrant background (PMB) suffering from gynecological malignancies and breast cancer to evaluate the quality of doctor-patient communication and cancer management compared to non-migrants (NM). Methods: This multicentre survey recruited patients with primary or recurrence of breast, ovarian, peritoneal, or fallopian tube cancer. The patients either filled out a paper form, participated via an online survey, or were interviewed by trained staff. A 58-item questionnaire was primarily developed in German and then translated into three different languages to reach non-German-speaking patients. Results: A total of 606 patients were included in the study: 54.1% (328) were interviewed directly, 9.1% (55) participated via an online survey, and 36.8% (223) used the paper print version. More than one quarter, 27.4% (166) of the participants, had a migrant background. The majority of migrants and NM were highly satisfied with the communication with their doctors. First-generation migrants (FGM) and patients with breast cancer were less often informed about participation in clinical trials (p < 0.05) and 24.5% of them suggested the help of an interpreter to improve the medical consultation. Second and third-generation migrants (SGM and TGM) experienced more fatigue and nausea than expected. Conclusions: Our results allow the hypothesis that training medical staff in intercultural competence and using disease-related patient information in different languages can improve best supportive care management and quality of life in cancer patients with migrant status

Testing ultrafast mode-locking at microhertz relative optical linewidth

We report new limits on the phase coherence of the ultrafast mode-locking process in an octave-spanning Ti:sapphire comb. We find that the mode-locking mechanism correlates optical phase across a full optical octave with less than 2.5 micro Hz relative linewidth. This result is at least two orders of magnitude below recent predictions for quantum-limited individual comb-mode linewidths, verifying that the mode-locking mechanism strongly correlates quantum noise across the comb spectrum.Comment: Expanded discussion to include correlated noise terms, made minor formatting changes, added a reference, and fixed typographical errors. 10 pages, 5 figure