Remote fabrication of nuclear fuel pellets

The equipment for remote fabrication of pellet fuels is in various stages of design, testing and evaluation. A pellet gaging system specifically designed to be maintained remotely has been demonstrated and is currently being interfaced with a programmable electro-mechanical manipulator to demonstrate completely automatic and remote disassembly and reassembly of the inspection unit. Pulsed magnetic welding of fuel rod end closures have been demonstrated. The solid-state welding technique allows the use of ultrasonics for weld inspection in place of traditional x-radiography. This welding and inspection method provides an attractive alternative for remote fuel fabrication. A new batch sintering furnace concept based upon aerospace technology is being developed. The furnace will have five to ten times the through-put of conventional batch furnaces and is easier to maintain than the horizontal furnaces in use today. Two high-speed mechanical press concepts (anvil and rotary) are currently being evaluated for remote operation and maintenance. The anvil press is especially attractive for remote fabrication due to its simplicity in set up and die change methods. All pellet fuel fabrication operations will be developed for remote operation and maintenance and representative fabrication rates will be demonstrated

Structural brain development between childhood and adulthood: Convergence across four longitudinal samples

Pathways through Adolescenc

Evidence of Color Coherence Effects in W+jets Events from ppbar Collisions at sqrt(s) = 1.8 TeV

We report the results of a study of color coherence effects in ppbar collisions based on data collected by the D0 detector during the 1994-1995 run of the Fermilab Tevatron Collider, at a center of mass energy sqrt(s) = 1.8 TeV. Initial-to-final state color interference effects are studied by examining particle distribution patterns in events with a W boson and at least one jet. The data are compared to Monte Carlo simulations with different color coherence implementations and to an analytic modified-leading-logarithm perturbative calculation based on the local parton-hadron duality hypothesis.Comment: 13 pages, 6 figures. Submitted to Physics Letters

ARIA 2016: Care pathways implementing emerging technologies for predictive medicine in rhinitis and asthma across the life cycle

The Allergic Rhinitis and its Impact on Asthma (ARIA) initiative commenced during a World Health Organization workshop in 1999. The initial goals were (1) to propose a new allergic rhinitis classification, (2) to promote the concept of multi-morbidity in asthma a

Search for electroweak production of single top quarks in ppˉp\bar{p} collisions.

We present a search for electroweak production of single top quarks in the electron+jets and muon+jets decay channels. The measurements use ~90 pb^-1 of data from Run 1 of the Fermilab Tevatron collider, collected at 1.8 TeV with the DZero detector between 1992 and 1995. We use events that include a tagging muon, implying the presence of a b jet, to set an upper limit at the 95% confidence level on the cross section for the s-channel process ppbar->tb+X of 39 pb. The upper limit for the t-channel process ppbar->tqb+X is 58 pb. (arXiv

Processos de democracia direta: sim ou não? Os argumentos clássicos à luz da teoria e da prática

Regularmente surgem controvérsias sobre os processos de democracia direta, dos quais os mecanismos mais frequentes são a iniciativa popular, o plebiscito e o referendo. Por um lado, há autores que defendem a posição de que essas instituições tornam o jogo político mais lento, caro, confuso e ilegítimo; outros defendem a posição contrária e argumentam que processos de democracia direta são fundamentais para os cidadãos e a qualidade da democracia. O presente estudo analisa esse tema em torno de sete questões, baseadas em considerações teóricas e pesquisas empíricas: 1. A questão entre o minimalismo e o maximalismo democrático; 2. A concorrência entre maioria e minoria; 3. A concorrência entre as instituições representativas e os processos de democracia direta; 4. A questão da competência dos cidadãos; 5. A questão dos efeitos colaterais dos processos de democracia direta; 6. A questão do tamanho do eleitorado; 7. A questão dos custos dos processos de democracia direta. As sete questões são analisadas a partir de uma revisão bibliográfica que considera tanto fontes nacionais como internacionais. O estudo mostra que os processos de democracia direta podem ser um complemento para as instituições representativas em um sistema democrático. O bom desempenho dos plebiscitos, referendos e iniciativas populares depende tanto da regulamentação destes como também do desempenho das outras instituições políticas e da situação socioeconômica de um país. O estudo permite ampliar e aprofundar o debate sobre processos de democracia direta no Brasil

El Telegrama del Rif: El Telegrama del Rif - Año XVIII Número 6612 - 1919 enero 12 (12/01/1919)

A kinetic study was conducted to provide information on oxidation of reactor graphites in the temperature range of 450 to 675 deg C and on the effects of reactor environment on oxidation rates. Among the parameters studied were chemical reactivity of the graphite, prior oxidation, a high intensity gamma flux during oxidation, variation of the surface-to-volume ratio of the graphite specimens, neutron bombardment prior to oxidation exposure, and gas flow rates. Rate equations showed apparent activation energies of 50 kcal/mole in the absence of radiation and 30 kcal/mole in the presence of a 1 x 10/sup 6/ r/hr gamma flux. (auth

EXPERIMENTAL EVALUATION OF THE COMBUSTION HAZARD TO THE EXPERIMENTAL GAS- COOLED REACTOR-PRELIMINARY BURNING RIG EXPERIMENTS

>An assembly was constructed which simulated the moderator coolant annulus in the Experimental Gas-Cooled Reactor. This assembly was preheated to various temperatures and air was passed through the coolant annulus. Under certain conditions it was demonstrated that self-sustained combustion of the graphite could occur. Rates of temperature rise were generally less than 1 deg C/ min until the graphite temperature exceeded 700 deg C and then rise rates became very high. In these cxperimcnts, the assembly was not operated in such a manner as to give ignition temperatures eharaeteristic of the EGCR. These tests were designed only to investigate the effects of changing such parameters as the rate of coolant flow, air humidity, prior oxidation on the graphite, and air inlet temperature. A later series of experiments to more closely duplicate the EGCR operating conditions was completed and will be reported in a second report, HW- 71182. (auth