Electron Microscopy Study of Ordinary Portland Cement and Ordinary Portland Cement–Pulverized Fuel Ash Blended Pastes

Many ordinary portland cement (OPC) OPC–pulverized fuel ash (pfa) blended pastes of various ages have been examined using transmission electron microscopy, energy dispersive X-ray analysis, and scanning electron microscopy. In addition to the phases commonly identified in OPC pastes, such as CH, CSH, AFt, and AFm, we found areas of pooriy crystalline iron-containing material intermixed with CSH and needles of hydrotalcite-like composition. The iron-containing material may be the precursor of hydrogarnet phases identified in older pastes by other authors. In the pfa-blended cements, some of the pfa particles reacted to give a radially fibrillar gel, and others showed areas of well-crystallized hydrogarnet within the clearly defined outer boundary of the particle. Unreactive pfa particles had a rim of fibrillar CSH gel around the particle. The general fine-scale microstructure of the OPC-pfa-blended pastes was similar to that in OPC pastes alone, but the CSH gel material had a lower C:S ratio.     

History and status of state natural resource systems

During the 1960's and 1970's there was a trend toward the development of natural resource information systems in state governments encouraged by the need for cost-efficient tools to manage the array of environmental legislation adopted during this period. Additional catalysts included rapidly emerging data management and remote sensing technologies, particularly NASA's Landsat Program. The ultimate success of these systems is dependent upon broad-based political support and their ability to satisfy decision-related needs within each state. Systems tend to be discontinued because of political and economic factors rather than technical problems. The 1980s offer a challenge to utilize excelling technologies for networking capabilities to build consistency, cost-efficiency and effectiveness into resource-related decision-making.     

Training mental health practitioners to assist families of persons who have a psychiatric disability.

Reports on the development, implementation, and evaluation of an 18-hr in-service training program designed to improve the knowledge and change the attitudes practitioners have about families in which there is a member with mental illness. 47 practitioners (aged 26+ yrs) from a community mental health center served as Ss. Comparisons between practitioners who received training (n?=?29) and those who did not suggest that this model is an effective method of training practitioners. Trained practitioners reported more positive attitudes about providing services and information to families and more contact concerning educational and supportive topics. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Self-concept changes of junior high students.

Previous studies have identified a relationship between self-concept and school behavior. The present study investigated whether self-concept (as measured by Bills's Index of Attitudes and Values) and school behavior of problem junior high school students could be changed by participation in a teacher helper program in an elementary school. Ss matched on grade (8th or 9th) sex, and GPA were randomly assigned to an experimental or a control group (n = 12). Self-concept ratings of experimental Ss who participated in the teacher helper program for 8 wks significantly increased during this period, while controls did not change. Neither group changed significantly in attendance or GPA. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attachment of Listeria monocytogenes on ready-to-eat meats

Five individual strains of Listeria monocytogenes and a mixed cocktail of all five were studied for attachment on frankfurters, ham, bologna, and roast beef relative to their cell surface characteristics. The ratio of strongly attached (sessile) L. monocytogenes cells compared with total (sessile and planktonic) attached cells on ready-to-eat meats was also determined. Because bacterial cell surfaces were characterized by net negative charge and hydrophobicity, electrostatic interaction chromatography and cationized ferritin methods were chosen to study net negative charge distribution on the bacterial cell surface, whereas hydrophobic interaction chromatography and contact angle measurement were used to examine the cell surface hydrophobicity. No differences (P > 0.05) were observed in cell surface charge or cell surface hydrophobicity among strains. Approximately 84 to 87% L. monocytogenes were found to attach strongly to ready-to-eat meats within 5 min. No differences (P > 0.05) were found among strains or among meats. Micrographs observed from scanning electron microscopy showed no differences among the strains but showed a difference in age of cells (mixed culture) in terms of surface negative charge distribution. More surface negatively charged sites were observed at 0 and 7 days and much fewer at 3 days during storage of washed, harvested cells in buffer at 4 degrees C (aged cells under cold and nutrient deprivation), indicating a possible change in cell surface properties. Because no difference in strains was observed, the contact angle measurement study was carried out with the five-strain mixed culture. The surface hydrophobicity increased in frankfurters, decreased in roast beef, and was unchanged in ham and bologna as a result of inoculation.     

Modelling the inactivation of Escherichia coli ATCC 25922 using pulsed electric field

Microbial tests were conducted to determine the effect of pulsed electric field treatment on microbial inactivation of gram negative Escherichia coli ATCC 25922 suspended in simulated milk ultra filtrate (SMUF). Kinetic analysis of microbial inactivation due to combined pulsed electric field (PEF) and thermal treatments of E. coli was investigated. A generalized correlation for the inactivation rate constant as a function of both electric field intensity and treatment temperature was derived. Comparison between experimental and theoretical variation of E. coli concentration with time after PEF treatment in a complete recirculation mode was conducted using the inactivation kinetics developed from the single pass measurements.

Industrial relevance

PEF technology has a tremendous potential to replace thermal pasteurisation for products which are sensitive to temperature. In this work a pulsed electric field process was mathematically modelled and a generalized correlation for the inactivation rate constant as a function of electric field intensity and treatment temperature was derived. The correlation is needed for the design of industrial PEF systems.     

3Desque: interface elements for a 3D graphical user interface

This paper explores some design possibilities and constraints for 3D enhancements of graphical user interfaces (GUIs). This is done with the aim of conveying more information in less screen space, while avoiding visual clutter. Design elements include the use of ‘slapped‐back’ windows obtained by projecting windows and icons into three dimensions; ‘trays’, an alternative to folders or piles; the use of transparent ‘beams’ for indicating hierarchy; and the use of ‘periphs’ for a form of fisheye projection on window borders. In addition we employ shading and shadows to enhance the interface, and automatic placement algorithms to prevent visually confusing occlusion. By considering these approaches together, rather than in isolation, the interactions between the different modifications are made explicit. Copyright © 1999 John Wiley & Sons, Ltd.     

Accelerated publication 16.4% total-area conversion efficiency thin-film polycrystalline MgF2/ZnO/CdS/Cu(In,Ga)Se2/Mo solar cell

This communication reports an MgF₂/ZnO/CdS/Cu(In,Ga)Se₂/Mo/glass polycrystalline solar cell with a confirmed total-area conversion efficiency of 16.4%. the thin-film Cu(In,Ga)Se₂ absorber was fabricated by computer-controlled physical vapor deposition (PVD) from the elemental sources. the resulting absorber has a Gal/In compositional grading that we refer to as a notch. Capacitance-voltage (C-V) measurements also reveal a graded doping profile in the region near the electronic p-n junction. the enhanced device performance is characterized by an open-circuit voltage (V_oc) of 660 mV and a particularly high fill factor (FF) of 78.7%.