Hydrothermal Formation of Calcium Silicate Hydrates

The kinetics of solution of quartz and the crystallization of calcium silicate hydrate during hydro-thermal treatment of single crystals of quartz in saturated lime solutions were studied. Microscopic examination of sections of the product layer showed that the calcium silicate hydrate was of fibrous crystal habit and grew radially from nucleating centers in a general direction away from the quartz surface. X-ray diffraction established that the mineral was mainly xonotlite. The crystallization of the mineral did not follow the receding surface of the quartz; the product layer was extended only on the surface in contact with the lime solution. The silicate ions apparently diffused preferentially through the product layer although separate measurements proved that the membrane had no selective action against the diffusion of calcium ions. Plots of the weight of xonotlite versus square root of time gave straight lines indicating that the process was diffusion-controlled at 235° and 335°C.     

EXPERIMENTAL AND CORRELATIONAL STUDIES OF THE FEAR OF DEATH.

THE TECHNIQUES USED TO MEASURE THE FEAR OF DEATH ARE REVIEWED. THE EFFECTS OF DEMOGRAPHIC VARIABLES AND PERSONAL CHARACTERISTICS ARE DISCUSSED, AND THE LACK OF CONSISTENCY IN THE DIFFERENT STUDIES IS ATTRIBUTED TO LACK OF ATTENTION TO THE CONSISTENCY AND THE VALIDITY OF THE MEASURING INSTRUMENTS AND A FAILURE TO DETERMINE WHETHER THE DIFFERENT TECHNIQUES ARE ASSESSING THE SAME DIMENSION. THE CHOICE OF VARIABLES IS CRITICIZED FOR A LACK OF RELEVANCE TO THE GENESIS OF THE FEAR OF DEATH. (58 REF.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

NatureTime: Temporal Granularity in Simulation of Ecosystems

Granularity of time is an important issue for the understanding of how actions performed at coarse levels of time interact with others, working at finer levels. However, it has not received much attention from most AI work on temporal logic. In simpler domains of application we may not need to consider it a problem but it becomes important in more complex domains, such as ecological modelling. In this domain, aggregation of processes working at different time granularities (and sometimes cyclically) is very difficult to achieve reliably. We have proposed a new time granularity theory based onmodular temporal classes, and have developed a temporal reasoning system to specify cyclical processes of simulation models in ecology at many levels of time.     

Thermal Conductivity of Cr2O3 in the Vicinity of the Neel Transition

Thermal conductivity (A) data for two dense Cr₂O₃ samples are reported. The results, which span the temperature range 270 to 360 K, show an inflection near the Neel transition temperature, 308 K. An analysis shows that the slope of the higher-temperature portion of the λlD⁻¹−T curve is about what would be expected for ordinary 3-phonon U-process scattering. Above T_N the mean free path for phonon-spin scattering is constant and equal to ∼10 nm.     

Sport And Downtown Development Strategy If You Build It,Will Jobs Come?

ABSTRACT: Many policy analysts have cautioned against public spending for professional and amateur sports. Within the last year, numerous cities have received demands from major and minor league teams for investments. These investments by the public sector can involve hundreds of millions of dollars and are usually defended by the economic impact of the facilities or teams and the economic development and revitalization which will follow. Indianapolis formulated an economic development strategy which relied substantially on sports. In addition, its development policies did not involve one team or facility, but a series of investments. As a result, the policies followed in Indianapolis afford an opportunity to measure the ability of sport facilities to encourage other investments and enhance economic development. The results reported here indicate that a sports strategy, even one as pronounced and as articulated as that of Indianapolis, is likely to have an inconsequential impact on development and economic growth.     

AGE, CIGARETTE SMOKING, AND TESTS OF PHYSICAL FITNESS.

HYPOTHESIZED THAT SMOKING WOULD DECREASE SS' PERFORMANCE ON PHYSICAL FITNESS TESTS CALLING FOR STRENUOUS ACTIVITY, BUT NOT FOR TESTS CALLING FOR MILD ACTIVITY. 88 SS WERE GIVEN 5 PHYSICAL FITNESS TESTS AS PART OF THEIR WORK REQUIREMENT, AND THEN ASKED TO REPORT THE NUMBER OF PACKAGES OF CIGARETTES SMOKED PER DAY. A MULTIPLE LINEAR REGRESSION ANALYSIS OF THE RESULTS, USING AGE AS A COVARIATE AND AMOUNT OF SMOKING AS THE INDEPENDENT VARIABLE, SUPPORTED THE HYPOTHESIS. THE SMOKING CONDITIONS RESULTED IN SIGNIFICANT DIFFERENCES FOR THE MOST STRENUOUS TEST AND THE 2 MODERATELY STRENUOUS TESTS WITH PERFORMANCE SCORES DECREASING AS REPORTED SMOKING SCORES INCREASED. THE LEAST PHYSICALLY DEMANDING TESTS SHOWED NO SIGNIFICANT DIFFERENCES BETWEEN SMOKING CONDITIONS. AGE WAS AN IMPORTANT FACTOR IN ACCOUNTING FOR SS' PERFORMANCE ON ALL OF THE TESTS. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

EXPLORATORY RESEARCH ON THE BEHAVIOR OF MEMBERS OF ELECTED LOCAL GOVERNMENT CHARTER COMMISSIONS

While much attention has been given to local government reform over the years, the focus has been on campaigns to influence voters and the substantive recommendations made by local government commissions. Relatively little research has been conducted on the charter-writing process. In this paper the findings of an exploratory study on the relationship of charter commission members' personal goals to their governmental change preferences are presented. To aid in organizing and analyzing data, a theoretical framework was developed. The framework was useful in explaining and predicting members' general preferences regarding government changes and in analyzing the reasons for their preferences. In addition, variables affecting individual and group dynamics are discussed relative to the impact of these variables on the attainment of a member's personal goals and structural change preferences.     

A fast experimental beam hardening correction method for accurate bone mineral measurements in 3D μCT imaging system

Bone mineral density plays an important role in the determination of bone strength and fracture risks. Consequently, it is very important to obtain accurate bone mineral density measurements. The microcomputerized tomography system provides 3D information about the architectural properties of bone. Quantitative analysis accuracy is decreased by the presence of artefacts in the reconstructed images, mainly due to beam hardening artefacts (such as cupping artefacts). In this paper, we introduced a new beam hardening correction method based on a postreconstruction technique performed with the use of off‐line water and bone linearization curves experimentally calculated aiming to take into account the nonhomogeneity in the scanned animal. In order to evaluate the mass correction rate, calibration line has been carried out to convert the reconstructed linear attenuation coefficient into bone masses. The presented correction method was then applied on a multimaterial cylindrical phantom and on mouse skeleton images. Mass correction rate up to 18% between uncorrected and corrected images were obtained as well as a remarkable improvement of a calculated mouse femur mass has been noticed. Results were also compared to those obtained when using the simple water linearization technique which does not take into account the nonhomogeneity in the object.