Apparatus for electrical measurements of thin films from 77 to 1000 K

A novel method of mounting thin samples for electrical measurements is described. A vacuum chuck holds a mounting plate, which, in turn, holds the sample. Contacts on the mounting plate establish electrical connection to the sample. The attachment of wires directly to the samples is unnecessary. Measurements can be made at temperatures from 77 to 1000 K. As an application of the apparatus, resistivity and Hall measurements of a thin silicon carbide sample are presented

Compensation in epitaxial cubic SiC films

Hall measurements on four n-type cubic SiC films epitaxially grown by chemical vapor deposition on SiC substrates are reported. The temperature dependent carrier concentrations indicate that the samples are highly compensated. Donor ionization energies, E sub D, are less than one half the values previously reported. The values for E sub D and the donor concentration N sub D, combined with results for small bulk platelets with nitrogen donors, suggest the relation E sub D (N sub D) = E sub D(O) - alpha N sub N sup 1/3 for cubic SiC. A curve fit gives alpha is approx 2.6x10/5 meV cm and E sub D (O) approx 48 meV, which is the generally accepted value of E sub D(O) for nitrogen donors in cubic SiC

Experimental Results on the Interactions Between Hydrogen and Zirconium Claddings KFKI-2001-02/G (2001)

Experiments were performed with Zr1%Nb and Zircaloy-4 alloys to study the interaction between hydrogen and Zr containing cladding materials. Four main activities are summarised in the report: · equilibrium solubility of hydrogen in cladding with oxygen content, · escape of hydrogen during steam oxidation, · escape of hydrogen during steam oxidation of cladding alloys with H-content, · delaying effect of surface oxide layer on the hydrogen absorption from gas phase by the Zr alloys

Effects of Crown (carbathiin and thiabendazole), Allegiance FL (metalaxyl), Vitaflo 280 (carbathiin and thiram), and Apron Maxx (fluodioxonil and metalaxyl) on N2 fixation of chickpea, dry bean, lentil, and pea

Non-Peer Reviewe

Efficacy of Vitaflo 280 to control soil- and seed-borne diseases of pea and lentil, and compatibility with rhizobium inoculants

Non-Peer ReviewedLentil (Lens culinaris Medikus) and pea (Pisum sativum L.) have the ability to fix dinitrogen (N2) from the atmosphere. Rhizobium inoculants are applied to the seed to ensure effective N2 fixation. In addition, fungicidal seed treatments are recommended to control extremely aggressive diseases such as Ascochyta, Botrytis, Fusarium, and Rhizoctonia seedling blight. To determine the efficacy of Vitaflo 280 to control seedling blight of pea and lentil caused by Botrytis cinerea, Mycosphaerella pinodes (Ascochyta blight), Rhizoctonia solani and Fusarium spp. experiments were established at several locations and years in western Canada. To determine the effect of Crown, Allegiance FL, Vitaflo 280, and Apron Maxx on the ability of Rhizobium inoculants to nodulate and fix N2 from the atmosphere experiments were established at two locations in Saskatchewan in 2002. Vitaflo 280 at the recommended rates effectively controls seedling blight of lentil caused by seed-borne Botrytis cinerea and soil-borne Fusarium spp and Rhizoctonia solani. Vitaflo 280 at the recommended rates effectively controls seedling blight of pea caused by seed-borne Mycosphaerella pinodes and soil-borne Fusarium spp and Rhizoctonia solani. In addition, Allegiance FL, Crown, Vitaflo 280, and Apron Maxx at the recommended rates have no effect on visual nodulation or the ability of the Rhizobium to fix N2 from the atmosphere

Crop-Specific EU Aid and Smallholder Food Security in Sierra Leone

The article analyses the viability of promoting crop-specific programs as a mean to improve smallholder net farm income and food security. The case study explores the relevance of European Union Stabilisation of Export Earnings (STABEX) funds in supporting Sierra Leone’s agricultural development agenda. By analysing the drivers of food security for a number of targeted smallholders in the two most important agricultural zones of Sierra Leone, it is possible to compare the suitability of crop-specific support (in rice, cocoa and coffee) versus general aid programs (public infrastructure, on and off farm diversification opportunities, sustainable practices, access to productive assets, etc.). The results indicate that crop diversification strategies are widespread and closely related to risk minimisation and enhanced food security among smallholders. Similarly, crop-specific programs mainly focusing on commercialisation tend to overlook important constraints associated to self-consumption and productivity

Seedling vigor variation among 80 recombinant chromosome substitution lines (RCSL) of barley (Hordeum vulgare)

del Pozo, A (del Pozo, Alejandro). Univ Talca, Fac Ciencias Agr, Talca, Chile.Seedling vigor of 80 recombinant chromosome substitution lines (RCSL) of barley (Hordeum vulgare). Cien. Inv. Agr. 38 (1): 137-147. The seedling vigor of 80 barley recombinant chromosome substitution lines (RCSLs) was measured for selecting high seedling vigor genotypes. The RCSLs were derived from a cross between H. vulgare subsp. spontaneum and H. vulgare subsp. vulgare 'Harrington'. The work was carried out under greenhouse conditions during the summer of 2008. The experimental design was an alpha lattice with 3 replicates. In each replicate, 40 plants were established, distributed in eight polyethylene pots containing sand as substrate, which were fertilized an irrigated. The emergence of seedlings, number of leaves and shoots, dry matter of leaves, shoots and roots and leaf area of fully expanded leaves were measured. In addition, growth indices were calculated: emergence rate, leaf appearance rate, relative leaf expansion rate, relative growth rate (RGR), net assimilation rate (NAR), leaf area ratio (LAR) and the allometric coefficient (K) between root and shoot thy matter. All calculated indices varied significantly among genotypes (P <= 0.05) and some RCSLs showed better early vigor associated traits than 'Harrington'. The dry matter accumulation 30 DAS (when the experiment ended) was significant and positively correlated with the RGR (r=0.61; P <= 0.05) and NAR (r=0.41; P <= 0.05). The K coefficient was negatively correlated with NAR (r=-0.40, P <= 0.05). The genotypes with the greatest seminal vigor were the RCSLs 45, 92, 112 and 'Harrington', whereas the RCSLs 5, 19,47 and 121 presented the lowest seminal vigor

Charge-Stripe Order and Superconductivity in Ir1−xPtxTe2\mathrm{Ir_{1-x}Pt_xTe_2}

A combined resistivity and hard x-ray diffraction study of superconductivity and charge ordering in $\mathrm{Ir_{1-x}Pt_xTe_2}$, as a function of Pt substitution and externally applied hydrostatic pressure, is presented. Experiments are focused on samples near the critical composition $x_c\sim 0.045$ where competition and switching between charge order and superconductivity is established. We show that charge order as a function of pressure in $\mathrm{Ir_{0.95}Pt_{0.05}Te_{2}}$ is preempted - and hence triggered - by a structural transition. Charge ordering appears uniaxially along the short crystallographic (1,0,1) domain axis with a $\mathrm{(\frac{1}{5},0,\frac{1}{5})}$ modulation. Based on these results we draw a charge-order phase diagram and discuss the relation between stripe ordering and superconductivity.Comment: 8 pages, 4 figures: Accepted in Scientific Report

The Detection, Characterization and Tracking of Recent Aleutian Island Volcanic Ash Plumes and the Assessment of Their Impact on Aviation

The Aleutian Islands of Alaska are home to a number of major volcanoes which periodically present a significant hazard to aviation. During summer of 2008, the Okmok and Kasatochi volcanoes experienced moderate eruptive events. These were followed a dramatic, major eruption of Mount Redoubt in late March 2009. The Redoubt case is extensively covered in this paper. Volcanic ash and SO2 from each of these eruptions dispersed throughout the atmosphere. This created the potential for major problems for air traffic near the ash dispersions and at significant distances downwind. The NASA Applied Sciences Weather Program implements a wide variety of research projects to develop volcanic ash detection, characterization and tracking applications for NASA Earth Observing System and NOAA GOES and POES satellites. Chemistry applications using NASA AURA satellite Ozone Monitoring System (OMI) retrievals produced SO2 measurements to trace the dispersion of volcanic aerosol. This work was complimented by advanced multi-channel imager applications for the discrimination and height assignment of volcanic ash using NASA MODIS and NOAA GOES and POES imager data. Instruments similar to MODIS and OMI are scheduled for operational deployment on NPOESS. In addition, the NASA Calipso satellite provided highly accurate measurements of aerosol height and dispersion for the calibration and validation of these algorithms and for corroborative research studies. All of this work shortens the lead time for transition to operations and ensures that research satellite data and applications are operationally relevant and utilized quickly after the deployment of operational satellite systems. Introductio