Hydrothermal crystallization of Sb3 (Sbx5 Nb1-x5 )O4 and their properties

Solid solution crystals of Sb³⁺(Sb_x⁵⁺Nb_1-x⁵⁺)O₄ (x=0-0126) were grown hydrothermally in the Sb₂O₃-Sb₂O₅- Nb₂O₅ -H₂O-KH₂F₂-H₂O₂ system by controlling the composition by means of the redox potential end the pH values. An increase of x decreases the ferroelectric Curie temperatures.     

The US insulation market

The US National Energy Plan is impressive in its determination to conserve energy in American homes. The US President has set the goal of bringing 90% of the nation's homes up to minimum federal insulation standards by 1985. At present, however, the home insulation industry is operating at full capacity, and demand for insulation significantly exceeds supply. This article briefly highlights the situation and indicates what steps the federal government is taking to mitigate the impact of the supply deficiency.     

A novel catalyst for the cure of carboxy-terminated polybutadienes

The catalysis of the reaction between carboxylic acids and epoxides was examined in general and with special reference to the cure of carboxy-terminated polybutadienes. It was established that the most active catalysts were the chromium chelates of salicylic acid or substituted salicylic acids. 3,5-Diiso-propylsalicylato chelates were studied in detail because of their solubility advantages. Reaction mechanisms are proposed which are in agreement with the kinetic data. A variety of applications were established for the new chelate catalyst. They include: synthesis of hydroxyalkyl carboxylic acids; efficient low-temperature cure of liquid rubbers with possible regulation of chain extension and crosslinking; and use of the catalytic system for room-temperature-cured, midly acid adhesives of high strength and rubber-modified epoxy resins.     

Energy scarcity and economic growth reconsidered

The analysis in this paper is concerned with the effect of energy scarcity on economic growth in the United States. After defining the notion of scarcity and introducing two measures of scarcity, unit costs and relative energy price, changes in the trend in resource scarcity for natural gas, bituminous coal, anthracite coal, and crude oil over the most recent three decades are investigated. Each of the energy resources became significantly more scarce resources during the decade of the 1970s in the Malthusian Stock Scarcity and Malthusian Flow Scarcity sense. Unit costs exhibit a similar change for natural gas and crude oil but not for bituminous coal and anthracite coal. The situation reversed itself during the 1980s. Natural gas, bituminous coal, anthracite coal, and crude oil all became significantly less scarce resources during the decade of the 1980s than they had been during the 1970s. That is, the increase in scarcity as measured by relative energy prices observed during the decade of the 1970s was not reversed completely during the 1980s for natural gas and crude oil. Unit costs for natural gas and crude oil demonstrate analogous patterns and test results. Given that change has taken place, it has implications for future economic growth to the extent resource scarcity and economic growth are interrelated. To see whether this is a relevant concern, subsequent to the examination of changing resource scarcity trends, an objective effort is made to identify a long-run equilibrium relationship between energy scarcity and economic growth. Relying on co-integration techniques, only for crude oil is there a suggestion that resource scarcity has affected economic growth in the United States over the period 1889–1992.     

Estimating the agricultural demand for natural gas and liquefied petroleum gas in the presence of measurement error in the data

The paper begins by discussing the importance of accurate estimates of the price elasticity of demand and some of the problems frequently encountered in obtaining these estimates. To these problems is added that associated with inaccuracy in the measurement of the dependent variable and one or more of the independent variables that affect the quantity demanded. Two diagnostics, i.e. the regression coefficient bounds and the bias correction factor, have been introduced to assess the effect that such measurement error has on the estimated coefficients of demand relationships. The use of these diagnostics will aid in assessing the integrity of the estimates obtained. In considering the demand for natural gas and the demand for liquefied petroleum gas by farmers in the USA, both the quantity demanded and the price data available for demand model estimation purposes contain measurement error. The regression coefficient bounds diagnostic was used to indicate a range over which the true price responsiveness of farmers to changes in energy prices lies. The results suggest that each 1% increase (decrease) in the price of energy will result in a decrease (increase) of between 0.41 and 0.17% in the quantity of natural gas demanded and a decrease (increase) of between 0.48 and 0.07% in the quantity of liquefied petroleum gas demanded. The bias correction factor was computed to evaluate the magnitude of the underestimation of the responsiveness of the quantity of natural gas and liquefied petroleum gas demanded to a change in the number of acres irrigated. For natural gas, the under-estimation was 26.5%, whereas, for liquefied petroleum gas, it was 9.5%.     

Impact of price variations on the consumption of electrical energy

This analysis is directed at looking at the impact of changing prices on the sectoral demand for electrical energy in the United States. By using a cross correlation test for unidirectional causality, it is shown that, in the case of the residential demand, the commercial demand and the industrial demand, the quantity consumed is affected by changing prices. The reverse is also true. Since bidirectional causality cannot be statistically rejected, any estimation of the demand for electrical energy must be peformed in a simultaneous framework to avoid specification errors and their associated problems.     

On the modified conjugate gradient method in cloth simulation

The seminal paper on cloth simulation by Baraff and Witkin [4] presents a modified preconditioned conjugate gradient (MPCG) algorithm for solving certain large, sparse systems of linear equations. These arise when employing implicit time integration methods aimed at achieving large step cloth simulation in the presence of constraints.This paper improves the robustness and efficiency of this MPCG algorithm. We prove convergence. For this, we recast the algorithm into a linear algebra setting, identifying its filtering procedure as an orthogonal projection. This leads not only to a convergence proof but also to a correction in the initiation stage of the original algorithm that improves its efficiency. We give an example to illustrate the performance improvement offered by this correction.