222 research outputs found
Does Financial Structure Matter?
We address the issue of whether financial structure influences economic growth. Three competing views of financial structure exist in the literature: the bank-based, the market-based and the financial services view. Recent empirical studies examine their relevance by utilizing panel and cross-section approaches. This paper, for the first time ever, utilizes time series data and methods, along with the Dynamic Heterogeneous Panel approach, on developing countries. We find significant cross-country heterogeneity in the dynamics of financial structure and economic growth, and conclude that it is invalid to pool data across our sample countries. We find significant effects of financial structure on real per capita output, which is in sharp contrast to some recent findings. Panel estimates, in most cases, do not correspond to country-specific estimates, and hence may proffer incorrect inferences for several countries of the panel.Financial Structure, Economic Development, Vector Error- Correction Model, Dynamic Heterogeneous Panels
Dependence of the critical temperature of laser-ablated YBa2Cu3O(7-delta) thin films on LaAlO3 substrate growth technique
Samples of LaAlO3 made by flame fusion and Czochralski method were subjected to the same temperature conditions that they have to undergo during the laser ablation deposition of YBa2Cu3O(7 - delta) thin films. After oxygen annealing at 750 C, the LaAlO3 substrate made by two methods experienced surface roughening. The degree of roughening on the substrate made by Czochralski method was three times greater than that on the substrate made by flame fusion. This excessive surface roughening may be the origin of the experimentally observed lowering of the critical temperature of a film deposited by laser ablation on a LaAlO3 substrate made by Czochralski method with respect to its counterpart deposited on LaAlO3 substrates made by flame fusion
Sequentially evaporated thin Y-Ba-Cu-O superconductor films: Composition and processing effects
Thin films of YBa2Cu3O(7-beta) have been grown by sequential evaporation of Cu, Y, and BaF2 on SrTiO3 and MgO substrates. The onset temperatures were as high as 93 K while T sub c was 85 K. The Ba/Y ratio was varied from 1.9 to 4.0. The Cu/Y ratio was varied from 2.8 to 3.4. The films were then annealed at various times and temperatures. The times ranged from 15 min to 3 hr, while the annealing temperatures used ranged from 850 C to 900 C. A good correlation was found between transition temperature (T sub c) and the annealing conditions; the films annealed at 900 C on SrTiO3 had the best T sub c's. There was a weaker correlation between composition and T sub c. Barium poor films exhibitied semiconducting normal state resistance behavior while barium rich films were metallic. The films were analyzed by resistance versus temperature measurements and scanning electron microscopy. The analysis of the films and the correlations are reported
Ternary refrigerant compositions containing fluorinated ethers as replacements for R-22
Refrigerant compositions include mixtures of at least three different components, including a fluorinated ether with at least one of a second fluorinated ether, an ether and a fluorinated hydrocarbon. Also, methods for cooling a body include compressing such a refrigerant composition and bringing the body into heat transfer relation to it. The disclosed refrigerant compounds have refrigerant-significant properties similar to those of R-22, and they can be employed in place of or as drop-in substitutes in refrigeration apparatus designed for R-22 application
Ternary refrigerant compositions which contain perfluoroorgano sulfur compounds as replacements for R-22
Refrigerant compositions include mixtures of at least three different components, including a fluorinated sulfur-containing compound with at least one of a fluorinated ether or a fluorinated hydrocarbon. Also, methods for cooling a body include compressing such a refrigerant composition and bringing the body into heat transfer relation to it. The disclosed refrigerant compounds have refrigerant-significant properties similar to those of R-22, and they can be employed as drop-in substitutes in refrigeration apparatus designed for R-22 application
Lunar Communication Terminals for NASA Exploration Missions: Needs, Operations Concepts and Architectures
NASA is conducting architecture studies prior to deploying a series of short- and long-duration human and robotic missions for the exploration of the Moon and Mars under the Vision for Space Exploration Initiative. A key objective of these missions is to establish and expand, through a series of launches, a system of systems approach to exploration capabilities and science return. The systems identified were Crew Exploration Vehicles, crew and cargo launch vehicles, crew EVA suits, crew and cargo landers, habitats, mobility carriers, and small, pressurized rovers. Multiple space communication networks and systems, deployed over time, will support these space exploration systems of systems. Each deployment phase will support interoperability of components and provide 20 years of legacy systems. In this paper, we describe the modular lunar communications terminals needed for the emerging lunar mission operational scenarios. These lunar communication terminals require flexibility for use in stationary, integrated, and mobile environments. They will support links directly to Earth, to lunar relay satellites, to astronauts and to fixed and mobile lunar surface systems. The operating concepts and traffic models are presented for these terminals within variety of lunar scenarios. A preliminary architecture is outlined, providing for suitable long-duration operations in the harsh lunar environment
Quantum Monte Carlo Study of Semiconductor Artificial Graphene Nanostructures
Semiconductor artificial graphene nanostructures where Hubbard model
parameter can be of the order of 100, provide a highly controllable
platform to study strongly correlated quantum many-particle phases. We use
accurate variational and diffusion Monte Carlo methods to demonstrate a
transition from antiferromagnetic to metallic phases for experimentally
accessible lattice constant nm in terms of lattice site radius ,
for finite sized artificial honeycomb structures nanopatterned on GaAs quantum
wells containing up to 114 electrons. By analysing spin-spin correlation
functions for hexagonal flakes with armchair edges and triangular flakes with
zigzag edges, we show that edge type, geometry and charge nonuniformity affect
the steepness and the crossover value of the phase transition. For
triangular structures, the metal-insulator transition is accompanied with a
smoother edge polarization transition.Comment: 5 pages, 5 figures; references added, several system sizes added,
typos corrected; abstract update
INDOOR RADON SURVEY IN NEPAL USING PASSIVE TECHNIQUE SOLID STATE NUCLEAR TRACK DETECTOR
Context: It has been proved from many epidemiological studies that the inhalation of the radioactive, inert gas radon (222Rn) is the main cause of lungs cancer after smoking. Objective: The survey was conducted to estimate the indoor radon concentration, the annual effective dose rate and the annual dose equivalent rate to the lung. Material and Methods: Altogether 50 dwellings were chosen randomly at 5 different districts of Nepal. The dosimetric measurements were carried out over a period of 3 months using time-integrated passive radon detectors, CR-39 based on type II Solid State Nuclear Track Detector (SSNTD) technique. The type of houses was concrete with plastered walls and mud house. Results: The minimum concentration of radon in the study areas was found to be <20Bq.m-3 and the maximum concentration was 110±20Bq.m-3. Also the corresponding values of annual effective dose and annual equivalent dose to the lung respectively varied from <0.60 to 3.30mSv.y-1 and 0.16—10-7 to 0.88×10-7 Sv.y-1. The uncertainty was measured at 95% confidence level. Conclusion: The indoor radon concentration varies considerably with the ventilation condition, lifestyle of the people, construction of the dwellings and climate of the areas. The measurements show that the radon concentrations were found to be well below the reference levels of ICRP.
KEYWORDS: Indoor Radon; Annual Effective Dose; CR-39; Ventilation Condition; Dwelling
INDOOR RADON SURVEY IN NEPAL USING PASSIVE TECHNIQUE SOLID STATE NUCLEAR TRACK DETECTOR
Context: It has been proved from many epidemiological studies that the inhalation of the radioactive, inert gas radon (222Rn) is the main cause of lungs cancer after smoking. Objective: The survey was conducted to estimate the indoor radon concentration, the annual effective dose rate and the annual dose equivalent rate to the lung. Material and Methods: Altogether 50 dwellings were chosen randomly at 5 different districts of Nepal. The dosimetric measurements were carried out over a period of 3 months using time-integrated passive radon detectors, CR-39 based on type II Solid State Nuclear Track Detector (SSNTD) technique. The type of houses was concrete with plastered walls and mud house. Results: The minimum concentration of radon in the study areas was found to be <20Bq.m-3 and the maximum concentration was 110±20Bq.m-3. Also the corresponding values of annual effective dose and annual equivalent dose to the lung respectively varied from <0.60 to 3.30mSv.y-1 and 0.16—10-7 to 0.88×10-7 Sv.y-1. The uncertainty was measured at 95% confidence level. Conclusion: The indoor radon concentration varies considerably with the ventilation condition, lifestyle of the people, construction of the dwellings and climate of the areas. The measurements show that the radon concentrations were found to be well below the reference levels of ICRP.
KEYWORDS: Indoor Radon; Annual Effective Dose; CR-39; Ventilation Condition; Dwelling
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