Radiation effects on silicon solar cells Third monthly progress report, Mar. 1-31, 1962

Radiation effects on silicon solar cell

Deep Well Injection of Liquid Radioactive Waste at Krasnoyarsk-26

Early methods of radioactive waste (RW) management in the former Soviet Union (FSU) were plagued with serious problems, which eventually prompted investigations into RW disposal methods that could provide a more reliable isolation of wastes from humans and the accessible environment. Deep well injection was chosen as a potential method of RW disposal, and, after extensive testing of the concept and numerous calculations of the likely consequences, discharges into deep geological formations at Krasnoyarsk-26 began between 1967 and 1969. This study was initiated because there were no published, independent assessments of the deep well injection systems at Krasnoyarsk-26 that used site-specific geology and data. The International Institute for Applied Systems Analysis (IIASA), in cooperation with Russian experts, undertook independent analyses of waste migration at the site, using data gathered by official Russian organizations over a 40-year period of exploration and exploitation of the repositories. The results of the modeling efforts carried out by IIASA and the Russian organizations -- VNIPIPT and IGEM -- indicate that the existing system of deep well injection at Krasnoyarsk is functioning as designed. Under the current best understanding of site conditions, there is very little likelihood that the injected wastes would reach the earth's surface prior to the time that the radioactive materials had been absorbed, decayed, or dispersed to concentrations far below standards set for drinking water

Deep Well Injection of Liquid Radioactive Waste at Krasnoyarsk-26: Analysis of Hypothetical Scenarios. Volume II

The Mining and Chemical Combine (MCC), located approximately 60 km north of the city of Krasnoyarsk,is one of two major sites in the Russian Federation where liquid radioactive wastes (LRW) are disposed of by deep well injection. Disposal of LRW at the MCC through the use of deep well injectio started in 1967. The Severny ("Northern") site, approximately 15 km north of the MCC, was launched after the completion of special geological surveys and explorations performed by istitutions of the Ministry of Geology and Russian Academy of Sciences. The site was designed by Mintom institutions. As of 1995, 5 million cubic meters (m3) of LRW had been injected into two deep aquifers at the site. The waste includes both radioactive fission products and nonradioactive chemicas used in reprocessing of spent fuel. The total activity, decay corrected to 1995, is approximately 250 million Curies (Ci). Detailed information about radioactive waste disposal at the Severny site is presented in Volume I of this report (Compton et al., 2000), which includes an evaluation of the safety of the site under normal post-operational conditions. For further information on the background data contained in Chapter 2 of that report, see Appendix I. The subject of the current report is the likelihood and consequence of hypothetical accidents and extreme natural events after site decommissioning, including a brief overview of the factors involved in the development of decommissioning plans at the site

Toward Collaboration and Community in Student-Faculty Relationships

Central to support services for deaf and hard-of-hearing college students is the creation of processes through which deaf students and hearing faculty recognize and respect each other’s cultural values. This article describes how conversations from a focus group of deaf students and conversations from a focus group of hearing faculty reflect cross-cultural relatedness and community within a traditional liberal arts university. Higgins’ (1980) conceptualization of interdependence and Palmer’s (1987) notions of relatedness and community served as the framework by which the conversations were analyzed. Communicating in class, using interpreters and notetakers, and establishing identity in the academic community emerged as themes that shaped both students’ and faculty members’ perceptions of deafness. The individual and group insights constructed a collaborative community within the larger context of the academy

Electrochemistry needs electrochemists: “goodbye to rotating discs”

The essential need for expert, fully trained electrochemists in the successful application of the subject is illustrated with several examples including the use of rotating electrodes and impedance spectroscopy where the use of the techniques in “black box” mode non-experts is likely to lead to disappointment or embarrassment

A Bose-Einstein Condensate in a Uniform Light-induced Vector Potential

We use a two-photon dressing field to create an effective vector gauge potential for Bose-condensed Rb atoms in the F=1 hyperfine ground state. The dressed states in this Raman field are spin and momentum superpositions, and we adiabatically load the atoms into the lowest energy dressed state. The effective Hamiltonian of these neutral atoms is like that of charged particles in a uniform magnetic vector potential, whose magnitude is set by the strength and detuning of Raman coupling. The spin and momentum decomposition of the dressed states reveals the strength of the effective vector potential, and our measurements agree quantitatively with a simple single-particle model. While the uniform effective vector potential described here corresponds to zero magnetic field, our technique can be extended to non-uniform vector potentials, giving non-zero effective magnetic fields.Comment: 5 pages, submitted to Physical Review Letter

Releases of Radionuclides to Surface Waters at Krasnoyarsk-26 and Tomsk-7

During the Cold War, production and testing of nuclear weapons in the United States and the Soviet Union led to major releases of radioactive materials into the environment. Although large studies have begun to clarify the magnitude and impact of releases in the United States, only since Perestroika has information become available to begin an evaluation of the significance of releases into the environment in the former Soviet Union (FSU). The Radiation Safety of the Biosphere (RAD) Project at the International Institute for Applied Systems Analysis (IIASA), begun in 1995, is currently evaluating the radiation legacy of the nuclear weapons complex in the FSU. Because the three sites of Chelyabinsk-65 (Mayak Production Association - MPA), Tomsk-7 (Siberian Chemical Combine - SCC), and Krasnoyarsk-26 (Mining and Chemical Combine - MCC) account for the vast majority of the radioactive materials released into the environment in the FSU, these sites are the focus of RAD's studies. Contamination of such sites has resulted from normal and emergency atmospheric releases (such as the 1993 tank explosion at Tomsk-7), discharge of radioactively contaminated waste and cooling waters into rivers, spills and leaks, and deep-well injection disposal of liquid radioactive waste. This study is limited to the impact of past discharges of radioactive materials to the Yanisei River at the MCC and the Tom River at the SCC. Future studies are planned to assess the significance of deep-well injection of wastes at the MCC

Carers matter: promoting the inclusion of families within acute inpatient settings

Despite their important contributions, many carers report feeling excluded by mental health services. Admission to a psychiatric ward can be a traumatic experience for both clients and their carers. Inpatient teams play a crucial role in engaging families but they report a lack of time, skills and confidence. This pilot study evaluated the feasibility, acceptability and potential benefits of introducing a family service across three acute wards. This comprised staff training, individual carer support and family intervention (FI). The service was found to be acceptable and feasible to implement. Family meetings on the ward increased following staff training, along with reported confidence in working with families. Following FI, significant improvements were found in carer distress, wellbeing, burden and negative illness perceptions and more carers reported having someone to confide in. The total number of ward complaints decreased following introduction of the service. Despite the difficulties implementing family work on the wards, it remains highly indicated. This pilot has shown it is possible to implement an effective and much needed service in an acute setting

Quantitative localized proton-promoted dissolution kinetics of calcite using scanning electrochemical microscopy (SECM)

Scanning electrochemical microscopy (SECM) has been used to determine quantitatively the kinetics of proton-promoted dissolution of the calcite (101̅4) cleavage surface (from natural “Iceland Spar”) at the microscopic scale. By working under conditions where the probe size is much less than the characteristic dislocation spacing (as revealed from etching), it has been possible to measure kinetics mainly in regions of the surface which are free from dislocations, for the first time. To clearly reveal the locations of measurements, studies focused on cleaved “mirror” surfaces, where one of the two faces produced by cleavage was etched freely to reveal defects intersecting the surface, while the other (mirror) face was etched locally (and quantitatively) using SECM to generate high proton fluxes with a 25 μm diameter Pt disk ultramicroelectrode (UME) positioned at a defined (known) distance from a crystal surface. The etch pits formed at various etch times were measured using white light interferometry to ascertain pit dimensions. To determine quantitative dissolution kinetics, a moving boundary finite element model was formulated in which experimental time-dependent pit expansion data formed the input for simulations, from which solution and interfacial concentrations of key chemical species, and interfacial fluxes, could then be determined and visualized. This novel analysis allowed the rate constant for proton attack on calcite, and the order of the reaction with respect to the interfacial proton concentration, to be determined unambiguously. The process was found to be first order in terms of interfacial proton concentration with a rate constant k = 6.3 (± 1.3) × 10–4 m s–1. Significantly, this value is similar to previous macroscopic rate measurements of calcite dissolution which averaged over large areas and many dislocation sites, and where such sites provided a continuous source of steps for dissolution. Since the local measurements reported herein are mainly made in regions without dislocations, this study demonstrates that dislocations and steps that arise from such sites are not needed for fast proton-promoted calcite dissolution. Other sites, such as point defects, which are naturally abundant in calcite, are likely to be key reaction sites