Characterisation of porous solids using small-angle scattering and NMR cryoporometry

The characteristics of several porous systems have been studied by the use of small-angle neutron scattering [SANS] and nuclear magnetic resonance [NMR] techniques. The measurements reveal different characteristics for sol-gel silicas, activated carbons and ordered mesoporous silicas of the MCM and SBA type. Good agreement is obtained between gas adsorption measurements and the NMR and SANS results for pore sizes above 10 nm. Recent measurements of the water/ice phase transformation in SBA silicas by neutron diffraction are also presented and indicate a complex relationship that will require more detailed treatment in terms of the possible effects of microporosity in the silica substrate. The complementarity of the different methods is emphasised and there is brief discussion of issues related to possible future developments

Implementation of Information power : the experiences of state library media consultants in New England.

The purpose of the study is to describe how four New England state library media consultants are working within their respective states toward the promotion of excellence in school library media centers through the implementation of the elements of Information Power, the current national school library standards. Literature describing the evolution of these standards, the current standards Information Power, and the activities of the school library media specialist and state library consultant associated with accomplishing the desired goals described in these standards are reviewed. This quantitative research project is conducted over a period of three years. Data were gathered through a combination of surveys, field notes, interviews, and questionnaires. Verbatim transcriptions were made of the audiotaped interviews. From these data were gathered responses to nineteen questions designed to provide the framework for the study--implementation activities of the state consultants. Conclusions drawn from these data indicate that the state library media consultants, in spite of having no regulatory powers, work actively in a myriad of ways to promote quality school library programs. Their changing environment brought about by individual perceptions, economics, technology, and educational reform creates a challenge to each of these participants

Raman spectroscopy study of the interface structure in (CaCuO2)n/(SrTiO3)m superlattices

Raman spectra of CaCuO2/SrTiO3 superlattices show clear spectroscopic marker of two structures formed in CaCuO2 at the interface with SrTiO3. For non-superconducting superlattices, grown in low oxidizing atmosphere, the 425 cm-1 frequency of oxygen vibration in CuO2 planes is the same as for CCO films with infinite layer structure (planar Cu-O coordination). For superconducting superlattices grown in highly oxidizing atmosphere, a 60 cm-1 frequency shift to lower energy occurs. This is ascribed to a change from planar to pyramidal Cu-O coordination because of oxygen incorporation at the interface. Raman spectroscopy proves to be a powerful tool for interface structure investigation

Velikhov Electrothermal Instability Cancellation by a Modification of Electrical Conductivity Value in a Streamer by Magnetic Confinement

We present a method, confirmed experimentally, allowing the cancellation of Velikhov instability by operating a local magnetic field reduction along a lane, which enhances local electric conductivity and electron-gas collision frequency, due to a local passage into a Coulomb collision regime and the subsequent lowering of the Hall parameter below its critical value, close to 2

Velikhov Electrothermal Instability Cancellation by a Modification of Electrical Conductivity Value in a Streamer by Magnetic Confinement

We present a method, confirmed experimentally, allowing the cancellation of Velikhov instability by operating a local magnetic field reduction along a lane, which enhances local electric conductivity and electron-gas collision frequency, due to a local passage into a Coulomb collision regime and the subsequent lowering of the Hall parameter below its critical value, close to 2

Molecular ions in L1544. I. Kinematics

We have mapped the dense dark core L1544 in H13CO+(1-0), DCO+(2-1), DCO+(3-2), N2H+(1-0), NTH+(3-2), N2D+(2-1), N2D+(3-2), C18O(1-0), and C17O(1-0) using the IRAM 30-m telescope. We have obtained supplementary observations of HC18O+(1-0), HC17O+(1-0), and D13CO+(2-1). Many of the observed maps show a general correlation with the distribution of dust continuum emission in contrast to C18O(1-0) and C17O(1-0) which give clear evidence for depletion of CO at positions close to the continuum peak. In particular N2D+(2-1) and (3-2) and to a lesser extent N2H+(1-0) appear to be excellent tracers of the dust continuum. We find that the tracers of high density gas (in particular N2D+) show a velocity gradient along the minor axis of the L1544 core and that there is evidence for larger linewidths close to the dust emission peak. We interpret this using the model of the L1544 proposed by Ciolek & Basu (2000) and by comparing the observed velocities with those expected on the basis of their model. The results show reasonable agreement between observations and model in that the velocity gradient along the minor axis and the line broadening toward the center of L1544 are predicted by the model. This is evidence in favour of the idea that amipolar diffusion across field lines is one of the basic processes leading to gravitational collapse. However, line widths are significantly narrower than observed and are better reproduced by the Myers & Zweibel (2001) model which considers the quasistatic vertical contraction of a layer due to dissipation of its Alfvenic turbulence, indicating the importance of this process for cores in the verge of forming a star.Comment: 24 pages, 9 figures, to be published in Ap

Genetic Modification of Stem Cells in Diabetes and Obesity

Genetic modification, or gene transfer, represents a method of treatment for several diseases. It has been used extensively in the context of cardiovascular diseases; however, its role in the context of metabolic diseases, such as diabetes and obesity, has remained largely unexplored. In this chapter, we will review the use of adult stem cells, focusing on endothelial progenitor cells (EPCs) and mesenchymal stromal cells (MSCs), in the context of diabetes. We have highlighted the use of viral vectors, particularly DNA viruses, as a tool for genetic modification to help stem cells survive and resist apoptosis in a hyperglycemic environment. We then discuss genetic modification of EPCs and MSCs to treat complications of diabetes and obesity. Although there are several unanswered questions in the field of metabolic diseases, the future application of gene transfer technology along with genetic modification of stem cells prior to the therapy holds significant therapeutic promise

List of Expenditures for Farm Labor Project 1943

A list of expenditures made in connection with the Brooklyn College Farm Labor Project, 1943, sent from Clerical Assistant, Marie C. Dore, to Mr. J. Harvey Cain (Board of Higher Education). February 23, 1944