What kind of crop insurance for Russia?

The paper starts with an analysis of the decline of Russian state-subsidised all-risk crop insurance during the transition period, describes the reorganisation of Russian crop insurance started in 1997 and 1998, and compares the Russian experience with the Czech Republic's strictly commercial approach to crop insurance reform. A discussion of the pros and cons of multiple-peril/all-risk crop insurance yields the result that there is no allocative justification for subsidised all-risk and multipleperil crop insurance. The subsequent discussion of alternative approaches to the design of crop insurance vindicates the Czech approach in so far as coverage is restricted to a limited number of perils. But this does not necessarily mean that the government should in all circumstances abstain from intervention in crop insurance markets. Under certain conditions compulsory insurance and subsidies can contribute to an increase in social welfare. The conclusion for Russia is that the present subsidised all-risk crop insurance scheme should be abolished and replaced with specific-risk crop insurance which offers coverage for a limited number of perils. A potential example would be insurance against the risk of yield losses by the hot and dry steppe wind sukhovei. The if and how of government intervention in crop insurance should be decided pragmatically, depending on the circumstances of the peril under consideration.Das Papier beginnt mit der Analyse des Niedergangs der russischen staatlich subventionierten AllGefahren-Ertragsausfallversicherung in der Transformationsperiode, stellt die in den Jahren 1997 und 1998 angelaufene Reorganisation der russischen Ernteversicherung dar und vergleicht die Erfahrungen in Rußland mit dem strikt kommerziellen Ansatz der Tschechischen Republik zur Reform der Ertragsausfallversicherung. Eine Diskussion des Für und Wider von Vielgefahren/ Allgefahren-Ertragsausfallversicherungen führt zu dem Ergebnis, daß es keine allokative Rechtfertigung für die subventionierte Allgefahren/Vielgefahren-Ertragsausfallversicherung gibt. Im Anschluß werden alternative Formen der Ausgestaltung von Agrarversicherungssystemen diskutiert. Diese Analyse bestätigt die Richtigkeit des tschechischen Ansatzes insoweit, daß die Deckung auf eine eng begrenzte Zahl von Gefahren beschränkt ist. Aber das heißt nicht notwendigerweise, daß der Staat unter allen Umständen von der Intervention in den Märkten für Ertragsausfallversicherungen absehen sollte. Unter bestimmten Bedingungen können Pflichtversicherung und Subventionen zu einem Zuwachs an sozialer Wohlfahrt führen. Die Konklusion für Rußland besteht darin, daß die gegenwärtige subventionierte Allgefahren-Ertragsausfallversicherung abgeschafft und durch eine Spezielle-Gefahren-Versicherung ersetzt werden sollte, die nur eine begrenzte Zahl von Gefahren abdeckt. Ein mögliches Beispiel wäre eine Versicherung gegen das Risiko von Ernteverlusten durch den heißtrockenen Steppenwind Suchovej. Das Ob und Wie staatlicher Eingriffe in die Ertragsausfallversicherung sollte pragmatisch und in Abhängigkeit vom konkreten Fall gesehen werden

Kaon-nucleon interaction in the extended chiral SU(3) quark model

The chiral SU(3) quark model is extended to include the coupling between the quark and vector chiral fields. The one-gluon exchange (OGE) which dominantly governs the short-range quark-quark interaction in the original chiral SU(3) quark model is now nearly replaced by the vector-meson exchange. Using this model, the isospin I=0 and I=1 kaon-nucleon S, P, D, F wave phase shifts are dynamically studied by solving the resonating group method (RGM) equation. Similar to those given by the original chiral SU(3) quark model, the calculated results for many partial waves are consistent with the experiment, while there is no improvement in this new approach for the P_{13} and D_{15} channels, of which the theoretical phase shifts are too much repulsive and attractive respectively when the laboratory momentum of the kaon meson is greater than 300 MeV.Comment: 19 pages, 16 figures. Accepted by Phys. Rev.

Dynamical coupled-channel study of K* K*bar and omega phi states in a chiral quark model

A dynamical coupled-channel study of K* K*bar state with isospin 0 and omega phi state is performed within both the chiral SU(3) quark model and the extended chiral SU(3) quark model by solving a resonating group method (RGM) equation. The model parameters are taken from our previous work, which gave a satisfactory description of the energies of the octet and decuplet baryon ground states, the binding energy of the deuteron, the nucleon-nucleon (NN) scattering phase shifts, and the hyperon-nucleon (YN) cross sections. The results show that the interactions of K* K*bar states are attractive, which consequently result in K* K*bar bound states with the binding energies of about 10-70 MeV, and contrarily, no omega phi bound state is obtained. The channel coupling effect of K* K*bar and omega phi is found to be considerably large, which makes the binding of K* K*bar 5-45 MeV deeper. The plausible interpretation of f_0(1710) and X(1812) being K* K*bar dominated states is briefly discussed.Comment: 7 pages, 4 figure

Atom Chips: Fabrication and Thermal Properties

Neutral atoms can be trapped and manipulated with surface mounted microscopic current carrying and charged structures. We present a lithographic fabrication process for such atom chips based on evaporated metal films. The size limit of this process is below 1$\mu$m. At room temperature, thin wires can carry more than 10$^7$A/cm$^2$ current density and voltages of more than 500V. Extensive test measurements for different substrates and metal thicknesses (up to 5 $\mu$m) are compared to models for the heating characteristics of the microscopic wires. Among the materials tested, we find that Si is the best suited substrate for atom chips

N K and Delta K states in the chiral SU(3) quark model

The isospin I=0 and I=1 kaon-nucleon $S$, $P$, $D$, $F$ wave phase shifts are studied in the chiral SU(3) quark model by solving the resonating group method (RGM) equation. The calculated phase shifts for different partial waves are in agreement with the experimental data. Furthermore, the structures of the $\Delta K$ states with L=0, I=1 and I=2 are investigated. We find that the interaction between $\Delta$ and $K$ in the case of L=0, I=1 is attractive, which is not like the situation of the $NK$ system, where the $S$-wave interactions between $N$ and $K$ for both I=0 and I=1 are repulsive. Our numerical results also show that when the model parameters are taken to be the same as in our previous $NN$ and $YN$ scattering calculations, the $\Delta K$ state with L=0 and I=1 is a weakly bound state with about 2 MeV binding energy, while the one with I=2 is unbound in the present one-channel calculation.Comment: 14 pages, 6 figures. PRC70,064004(2004

Airloads research study. Volume 2: Airload coefficients derived from wind tunnel data

The development of B-1 aircraft rigid wind tunnel data for use in subsequent tasks of the Airloads Research Study is described. Data from the Rockwell International external structural loads data bank were used to generate coefficients of rigid airload shear, bending moment, and torsion at specific component reference stations or both symmetric and asymmetric loadings. Component stations include the movable wing, horizontal and vertical stabilizers, and forward and aft fuselages. The coefficient data cover a Mach number range from 0.7 to 2.2 for a wing sweep position of 67.5 degree

Airloads research study. Volume 1: Flight test loads acquisition

The acquisition of B-1 aircraft flight loads data for use in subsequent tasks of the Airloads Research Study is described. The basic intent is to utilize data acquired during B-1 aircraft tests, analyze these data beyond the scope of Air Force requirements, and prepare research reports that will add to the technology base for future large flexible aircraft. Flight test data obtained during the airloads survey program included condition-describing parameters, surface pressures, strain gage outputs, and loads derived from pressure and strain gauges. Descriptions of the instrumentation, data processing, and flight load survey program are included. Data from windup-turn and steady yaw maneuvers cover a Mach number range from 0.7 to 2.0 for a wing sweep position of 67.5 deg

Multislice CT in the pre- and postinterventional evaluation of mesenteric perfusion

Multislice computed tomography angiography (CTA) has been found feasible for the evaluation of visceral vasculature. The development of multislice technology has overcome past limitations. First, the faster scanning speed increases volume coverage during a single breath-hold and improves the exploitation of contrast medium. Second, the better spatial resolution results in nearly isotropic voxels allowing reconstruction of high-resolution three-dimensional images with different algorithms. Volume rendering is capable of displaying the visceral vasculature from any external vantage point. Compared to conventional angiography, CTA not only delineates vessels but also depicts the anatomical relationship to adjacent structures and allows the evaluation of perfused organs. CTA also has become an emerging tool for the pre- and postinterventional assessment of vascular anatomy. The purpose of this pictorial essay is to present a spectrum of visceral vascular diseases and interventional and surgical therapies, and to highlight the role of postprocessing for their evaluatio