559 research outputs found
Proposed Method for the Verification of the LHC Bus Bar Splices during Commissioning at Cryogenic Conditions
The commissioning of the Large Hadron Collider at CERN includes the powering of about 1600 superconducting electrical circuits to currents ranging from 55ĂÂ A to 11.8 kA. A large number of splices (over 70'000) are present at the magnet interconnects, which can only be validated with current at cryogenic conditions. This paper discusses the thermal effects related to possible faulty splices during the powering of the circuits. The calculations of the quench and detection currents, as well as the hot spot temperatures, are described. The heat transfer model with the surrounding coolant and the current profiles inside the splices are presented. This study is completed with a sensitivity analysis on the hot spot temperature with respect to the model parameters. Finally, the implications with respect to the powering ramps and parameters to be applied during the first powering are discussed
Deforestation and Biomass Production in Miombo Forest in Huambo (Angola): A Balance between Local and Global Needs
Miombo is one of the most widely distributed ecosystems in Angola, with a great social and environmental value. Thus, the rural population uses the biomass as fuel and miombo provides important ecosystem services, such as its carbon sequestration capacity. The objectives of this work were (i) to assess deforestation in miombo forest in Huambo province (Angola) during the last 20 years, (ii) to evaluate carbon storage capacity of miombo, and (iii) to calculate the charcoal productive capacity of those forests. From 2000 to 2019, 359,130 ha (12.96%) were deforested in Huambo province. Thirty-six woody species were identified as major components of miombo forest, the most frequent being Albizia anthunesiana, Brachystegia spiciformis, Julbernardia paniculata, Monote spp., Brachystegia boemii, Isoberlinea angolensis, Anisophyllea boehmii, Syzygium guineense, and Erythrophleum africanum. The total biomass estimated in miombo forest was 195.05 Mg haâ1 (55.02 Mg haâ1 radical and 140.04 Mg haâ1 area), with a total wood volume of 78.57 m3 haâ1. This represents values of 91.67 Mg haâ1 of accumulated carbon and 336.13 Mg haâ1 of CO2 equivalent. The potential charcoal productivity was 15,359.9 kg haâ1, corresponding to 24.78 trees haâ1. The Annual Allowable Cutting Volume was 10.77 m3 haâ1 yearâ1, 14.13 m3 haâ1 yearâ1, 21.17 m3 haâ1, and 32.85 m3 haâ1 yearâ1 for rotation lengths of 55, 40, 25, and 15 years, respectively, corresponding to a potential annual charcoal productivity of 2107.08 Kg haâ1 yearâ1, 2762.96 Kg haâ1 yearâ1, 4139.21 Kg haâ1, and 422.56 Kg haâ1 yearâ1. However, deforestation rates in the last 19 years and low charcoal productive capacity could compromise the sustainability of the Miombo ecosystem and its value as an ecosystem service provider in the province if appropriate management strategies are not developed
Design and construction of a 1 m model of the low current superconducting quadrupole for the LHC insertions
About one hundred individually powered low current superconducting quadrupoles will be installed in the LHC insertions. One of the design requirements was to keep the excitation current of the magnet below 6 kA in view of minimizing the costs of the powering circuits. The design of the quadrupole is based on a 8.2 mm NbTi cable, and is designed for a nominal gradient of 200 T/m at 1.9 K. In this paper we present the design of the quadrupole and discuss the construction details of the 1 m single aperture model which has been recently completed
Influence of origin of the beans on protein quality and nutritive value of commercial soybean meals.
Chemical composition and correlations between chemical analyses and protein quality of 454 batches of SBM of 3 different origins (USA, n=168; Brazil (BRA), n=139, and Argentine (ARG), n=147) were studied. Samples were collected during a 6-yr period. SBM from USA had more CP, sucrose and stachyose and less NDF (P<0.001) than SBM from ARG and BRA. CP content was negatively related (P<0.001) with sucrose for USA meals and with NDF for ARG and BRA meals. Also, P content was positively related (P<0.01) with CP content of the meals. PDI and KOH solubility were higher (P<0.001) for USA than for ARG or BRA SBM, values that were positively related (P<0.001) with trypsin inhibitor activity of the meals. In addition, USA meals had more lys, met+cys, thr, and trp than BRA and ARG meals (P < 0.001). Per unit of CP, lys content was negatively related (P<0.001) with CP content for USA, positively for BRA, and no relations was found for ARG meals. It is concluded that nutritive values and protein quality of the meals varied widely among soybean origins. Consequently, the origin of the beans should be considered in the evaluation of the nutritive value of commercial SBM for non-ruminant animals
Eating Disorders as New Forms of Addiction
Eating disorders (ED) seem to share many characteristics with substance-related disorders (SRD). As very often the two conditions run together, it has been proposed that eating dysfunctions could be understood as behavioral forms of addiction. This has lead to the concept of âfood addiction,â a proposed new form of addiction. This chapter reviews recent research focusing on the relationship between ED and SRD. Three specific areas are addressed: (a) animal models that suggest the association between substance dependence and compulsive overeating; (b) epidemiological studies that confirm the comorbidity between ED and SRD; and (c) neuroimaging studies that reveal the existence of modifications in the reward circuits following binge eating and other eating dysfunctions. The data from the different studies can be integrated into a model based on the consideration of âfood addictionâ as a specific form of behavioral addiction that could be applied at least to a group of patients suffering from eating disorders
SĂndrome del tĂșnel radial: Epicondilitis resistente
Desde 1996 al 2003, fueron intervenidos 25 pacientes (26 extremidades) de sĂndrome del tĂșnel radial. Todos los procedimientos fueron realizados por el mismo cirujano y en el mismo hospital con un abordaje postero-externo del tĂșnel radial. Se realizĂł un seguimiento de todos los pacientes en el tiempo despuĂ©s de la cirugĂa de 4 meses a 6 años y 4 meses (tiempo medio de 22 meses). Los resultados fueron evaluados segĂșn los criterios de Roles y Mausdley; 12 pacientes tuvieron resultados excelentes (46.15%), 9 pacientes buenos (34.61%) y 5 pacientes regulares (19.23%). Once pacientes fueron tratados previamente de epicondilitis lateral (entesitis). La mayorĂa de los pacientes estĂĄn satisfechos con la cirugĂa refiriendo un alivio de la sintomatologĂa y una mejora de la funcionalidad tras la cirugĂa.Between 1996 and 2003, 25 patients (26 extremities) underwent decompression of the radial tunnel. All procedures were performed at the same surgeon and the same institution using posterior approach. The total 25 patients were available for follow-up evaluation alter surgery (range 4 months - 6 years and 4 months) with average of 22 months. The outcomes was determined using the original criteria of Roles and Mausdley, 12 patients were rated as excellent (46.15%), 9 patients has good results (34.61%) and 5 patients had fair results. Eleven patients were treated previously of tennis elbow. Most of the patients were satisfied and felt subjectively improved by the surgery. They obtained pain relief and better functional status after surgery
Diferencias en composiciĂłn quĂmica y relaciones con la calidad de la proteĂna de las harinas de soja segĂșn origen.
La harina de soja (HS) es la principal fuente de proteĂna utilizada en la fabricaciĂłn de piensos. En Europa, la mayor parte de las HS procede de uno de los tres principales paĂses productores: Estados Unidos (USA), Brasil (BRA) y Argentina (ARG). La composiciĂłn y valor nutricional de las HS varĂa entre paĂses de origen en funciĂłn de las variedades cultivadas, las condiciones agronĂłmicas y las condiciones de procesado (Grieshop et al., 2003; De Coca
et al., 2008, 2010; Frikha et al., 2012). En un trabajo anterior Mateos et al. (2011) presentaron los resultados obtenidos de una colecciĂłn de 385 muestras de HS recogidas
entre los años 2007 y 2010 procedentes de estos tres paĂses. El presente trabajo tiene como objetivo complementar los resultados anteriores con nuevas muestras procedentes de las cosechas de los años 2011 y 2012. Asimismo se presentarĂĄn las correlaciones mĂĄs destacadas entre componentes analĂticos y las variables de calidad de la proteĂna habitualmente utilizadas por la industria
Removal of paracetamol on biomass-derived activated carbon: Modeling the fixed bed breakthrough curves using batch adsorption experiments
The remediation of paracetamol (PA), an emerging contaminant frequently found in wastewater treatment plants, has been studied in the low concentration range (0.3â10 mg Lâ1) using as adsorbent a biomass-derived activated carbon. PA uptake of up to 100 mg gâ1 over the activated carbon has been obtained, with the adsorption isotherms being fairly explained by the Langmuir model. The application of Reichemberg and the Vermeulen equations to the batch kinetics experiments allowed estimating homogeneous and heterogeneous diffusion coefficients, reflecting the dependence of diffusion with the surface coverage of PA. A series of rapid small-scale column tests were carried out to determine the breakthrough curves under different operational conditions (temperature, PA concentration, flow rate, bed length). The suitability of the proposed adsorbent for the remediation of PA in fixed-bed adsorption was proven by the high PA adsorption capacity along with the fast adsorption and the reduced height of the mass transfer zone of the columns. We have demonstrated that, thanks to the use of the heterogeneous diffusion coefficient, the proposed mathematical approach for the numerical solution to the mass balance of the column provides a reliable description of the breakthrough profiles and the design parameters, being much more accurate than models based in the classical linear driving force.We gratefully thank Junta de AndalucĂa (P09-FQM-5156) and Spanish Ministry of Economy and Competitiveness (MINECO â Spain) (Project CTQ2012-36408) and Fondo Europeo de Desarrollo Regional (FEDER â Spain) for financial support
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