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Publication Metadata only Experimental determination of fractional thermal loading in an operating diode-pumped Nd: YVO4 minilaser at 1064 nm(Optical Soc Amer, 1999) Department of Physics; Sennaroğlu, Alphan; Faculty Member; Department of Physics; College of Sciences; 23851A practical in, situ method is described and used for determination of the fractional thermal-loading parameter eta(h) in an operating diode-pumped Nd:YVO4 minilaser at 1064 nm. Readily applicable to the thermal characterization of other solid-state media, the method is based on the fact that thermally induced lensing will cause the laser oscillation to be quenched at a critical pump power whose magnitude depends on the cavity configuration, thermo-optical properties of the gain medium, and, in particular, on the value of eta(h). In the experiments described here, a 0.5-mm-long coated Nd:YVO4 crystal with 3-at. % Nd concentration was used to construct the diode-pumped laser with a flat highly reflecting end mirror and an intracavity lens. For the method to be effective, the resonator was set up close to the edge of the stability range. Above the oscillation threshold, the pump power at which lasing was quenched because of the onset of the thermally induced resonator instability was measured as a function of the intracavity lens position. A numerical model that accounted for absorption saturation and pump-induced thermal lensing was then used to analyze the experimentally measured data with eta(h) as an adjustable parameter. The average best-fit value of eta(h) was determined to be 0.40 with an estimated statistical variation of 8%.Publication Metadata only Crystal structure of tetrasodium octaeuropium(ii) [octaphosphido(3-)]-bis[diphosphido(4-)]tetraaluminate(iii),NA 4EU8[AL4P8(P2) 2](Walter de Gruyter, 1998) Carrillo-Cabrera, W.; Peters, K.; Von Schnering, H.G.; Department of Chemistry; Somer, Mehmet Suat; Faculty Member; Department of Chemistry; College of Sciences; 178882N/APublication Metadata only Quantum chaos: a route through mixed-mode dynamics(Scientific and Technical research Council of Turkey - TUBITAK/Türkiye Bilimsel ve Teknik Araştırma Kurumu, 1997) Department of Chemistry; Yurtsever, İsmail Ersin; Faculty Member; Department of Chemistry; College of Sciences; 7129The quantal-classical mixed-mode dynamics provides a convenient tool for studying the transition from classical to quantum dynamics. In this work nonlinearly coupled oscillator systems whose classical motion display chaos are investigated under the time-dependent self-consistent-field approach so that one of the modes can be treated quantum mechanically. Lyapunov exponents for the mixed-mode system are defined through the use of Hamilton-Jacobi-like equations of motion for the quantal wavepacket. The classical modes seem to be more regularized when they are under the effect of quantum fields, however the Lyapunov exponents of the mixed-mode dynamics agree extremely well with those from classical calculations showing that chaos still survives in the mixed-mode philosophy.Publication Metadata only Privatisation and stock market efficiency: the British experience(Wiley, 1997) Hayri, A; Department of Economics; Yılmaz, Kamil; Faculty Member; Department of Economics; College of Administrative Sciences and Economics; 6111We present evidence that with its emphasis on wide-share-ownership the British privatisation program created heavy involvement of small investors in privatised stocks. Using standard market efficiency tests and maximum likelihood estimates of stationary fractional ARIMA models, we show that the pricing of privatised stocks in the London Stock Exchange was indeed inefficient, unlike the rest of the market. Together, these two pieces of evidence suggest that small investors, behaving like noise-traders, may be generating this inefficiency. Yet, we cannot rule out alternative explanations.Publication Metadata only The sensitivity of conformational free energies of the alanine dipeptide to atomic site charges(Wiley, 1997) Maye, Peter V.; Mezei, Mihaly; Department of Physics; Reşat, Haluk; Faculty Member; Department of Physics; College of Sciences; N/ADifferent atomic point charge sets are obtained for the are and C7,eq conformations of the alanine dipeptide by fitting the charges of each conformation to the respective ab initio electrostatic potential surfaces both individually and simultaneously, in both the united atom and the all-atom representations. Using these charge sets, the sensitivity of the relative conformational aqueous free energies to the atomic site charges is investigated. For this particular system, we find that the solute-water contributions to the conformational free energy differences have a rather weak dependence on site charges; the calculated intramolecular contributions, however, show a rather strong dependence on the atomic site charges. It is suggested that the calculated results for the alanine dipeptide using a single, simultaneously fit set of charges for both conformations are in better agreement with experiments than the calculations carried out with charges determined individually for each conformation. © 1997 John Wiley & Sons, Inc.Publication Metadata only Experimental determination of fractional thermal loading in an operating diode-pumped nd:yvo4 minilaser at 1064 nm(Optica Publishing Group, 1999) Department of Physics; Sennaroğlu, Alphan; Faculty Member; Department of Physics; College of Sciences; 23851A practical in, situ method is described and used for determination of the fractional thermal-loading parameter eta(h) in an operating diode-pumped Nd:YVO4 minilaser at 1064 nm. Readily applicable to the thermal characterization of other solid-state media, the method is based on the fact that thermally induced lensing will cause the laser oscillation to be quenched at a critical pump power whose magnitude depends on the cavity configuration, thermo-optical properties of the gain medium, and, in particular, on the value of eta(h). In the experiments described here, a 0.5-mm-long coated Nd:YVO4 crystal with 3-at. % Nd concentration was used to construct the diode-pumped laser with a flat highly reflecting end mirror and an intracavity lens. For the method to be effective, the resonator was set up close to the edge of the stability range. Above the oscillation threshold, the pump power at which lasing was quenched because of the onset of the thermally induced resonator instability was measured as a function of the intracavity lens position. A numerical model that accounted for absorption saturation and pump-induced thermal lensing was then used to analyze the experimentally measured data with eta(h) as an adjustable parameter. The average best-fit value of eta(h) was determined to be 0.40 with an estimated statistical variation of 8%.Publication Metadata only House allocation with existing tenants(Academic Press Inc, 1999) Abdülkadiroğlu, Atila; Department of Economics; Sönmez, Tayfun; Faculty Member; Department of Economics; College of Administrative Sciences and Economics; N/AIn many real-life applications of house allocation problems, whenever an existing tenant wants to move, he needs to give up his current house before getting another one. This practice discourages existing tenants from such attempts and results in loss of potentially large gains from trade. Motivated by this observation, we propose a simple mechanism that is Pareto efficient, individually rational, and strategy-proof. Our approach is constructive and we provide two algorithms, each of which can be used to find the outcome of this mechanism. One additional merit of this mechanism is that it can accommodate any hierarchy of seniorities.Publication Metadata only Political-ideological constraints on intra-basin cooperation on transboundary waters(Elsevier, 1997) Kut, Gün; N/A; Turan, İlter; Faculty Member; College of Administrative Sciences and Economics; N/AThis article offers a different perspective to the well known problems of water scarcity in the Middle East. It is argued that there are strong linkages between prevailing national ideologies and intra-regional water disputes. Domestic political necessities and commitments often limit foreign policy choices open to countries with regard to the settlement of water disputes. This tends to exacerbate existing conflict. Reasons given include ideologically intertwined issues related to national security, including food security and national independence in conjunction with a deep socio-cultural commitment to a prospering agricultural sector. Any proposed solution to Middle East water disputes needs to take ideological-political factors into account in addition to the physical, social, cultural and economic aspects.Publication Metadata only Crystal structure of tetrasodium octastrontium catena-[octaphosphido(3-)]-[diphosphido(4-)]tetraaluminate(iii) [diphosphide(4-)], NA4SR8[AL4P8(P2)][P 2](Walter de Gruyter, 1998) Carrillo-Cabrera, W.; Peters, K.; Von Schnering, H.G.; Department of Chemistry; Somer, Mehmet Suat; Faculty Member; Department of Chemistry; College of Sciences; 178882N/APublication Metadata only Weak convergence to a matrix stochastic integral with stable processes(Cambridge Univ Press, 1997) Department of Economics; Caner, Mehmet; Faculty Member; Department of Economics; College of Administrative Sciences and Economics; N/AThis paper generalizes the univariate results of Chan and Tran (1989, Econometric Theory 5, 354-362) and Phillips (1990, Econometric Theory 6, 44-62) to multivariate time series. We develop the limit theory for the least-squares estimate of a VAR(1) for a random walk with independent and identically distributed errors and for I(1) processes with weakly dependent errors whose distributions are in the domain of attraction of a stable law. The limit laws are represented by functionals of a stable process. A semiparametric correction is used in order to asymptotically eliminate the ''bias'' term in the limit law. These results are also an extension of the multivariate limit theory for square-integrable disturbances derived by Phillips and Durlauf (1986, Review of Economic Studies 53, 473-495). Potential applications include tests for multivariate unit roots and cointegration.