economia entre crises: Topics by WorldWideScience.org

The Stryker Brigade Combat Team. Rethinking Strategic ...

No abstract prepared.

2008-07-01

Antarctica and the Mediterranean high mountains. - NASA

... For short-warning crises in other regions, Marine Expeditionary Units, the 82nd Airborne Division, Special Operations Forces, and Air Force/Navy ...

Evidence from ammonoids and conodonts for multiple Early Triassic mass extinctions

como un factor determinante del maximo indice de fotosintesis y, consecuentemente potencial de produccion primaria. Comparaciones entre especies ...

UK PubMed Central (United Kingdom)

Ammonoids and conodonts, being characterized by exceptionally high background rates of origination and extinction, were vulnerable to global environmental crises, which characteristically intensified...Full Text Available

2009-09-08

Modeling of the induced damage in argilites. Interaction between civil-engineering barrier and geologic barrier; Modelisation de l'endommagement induit dans les argilites. Interraction entre barriere ouvragee et barriere geologique

Determination of the semi-empiric relationship among the physical density, the concentration and rate between hydrogen and manganese atoms, and a manganese sulfate solution; Determinacao da relacao semi-empirica entre a densidade fisica, concentracao e razao entre atomos de hidrogenio e manganes em uma solucao de sulfato de manganes

No abstract prepared.

1999-12-01

Revisiting new variant famine: the case of Swaziland

The bath of a manganese sulfate (BMS) is a system for absolute standardization of the neutron sources. This work establishes a functional relationship based on semi-empirical methods for the theoretical prediction of physical density values, concentration and rate between the hydrogen and manganese atoms presents in the solution of the BMS

2009-07-01

British Library Electronic Table of Contents (United Kingdom)

The ?new variant famine? hypothesis posits links between HIV/AIDS and new patterns of impoverishment, food insecurity and hunger, in southern and eastern Africa. This paper explores the relevance of the NVF hypothesis to understanding Swaziland?s recurrent food crises and high HIV prevalence. Evidence exists that all four markers of NVF are present in Swaziland. The national government and the international community will have to contend with this phenomenon in future planning for the wellbeing of Swazi citizens.

2009-01-01

Proton transport, an examination of model and experimental data for space environment protons; Blindage aux protons, comparaison entre modele et donnees experimentales pour les protons du rayonnement spatial

Correlation of Fe levels determined by ferritin and through human skin in vivo measurement using X-ray fluorescence (XRF); Correlacao entre os niveis de Fe determinados pela ferritina e pela medida in vivo na pele humana atraves da metodologia de fluorescencia de raios X (XRF)

We will examine modeling data for various orbits using modeling software and compare this with actual satellite flight result. In particular, we will discuss the contributions of trapped protons to total dose and the effectiveness of shielding.

1999-07-01

Joint effect of financial fragility and macroeconomic shocks on bank loan losses: Evidence from Europe

No abstract prepared.

2007-07-01

British Library Electronic Table of Contents (United Kingdom)

A reduced-form model including nonlinearities is estimated from pooled data from nine European countries during 1982-2004 to show the effects of macroeconomic shocks and financial fragility on bank loan losses. The main ingredients of the model are unanticipated-output and interest-rate shocks estimated from published macroeconomic and naive forecasts. The model fits the data well, capturing the extremely high levels of loan losses witnessed in different financial crises.

2011-01-01

Treatment and Course of Community-Acquired Pneumonia Caused by Atypical Pathogens

British Library Electronic Table of Contents (United Kingdom)

Objetivo Estudiar la evolucion de un grupo de neumonias extrahospitalarias causadas por germenes atipicos (Mycoplasma pneumoniae, Legionella spp., Coxiella burnetii y Chlamydophila pneumoniae) en funcion del tratamiento empirico recibido. Pacientes y metodos Entre enero de 1996 y febrero de 2001 ingresaron en nuestra unidad 390 casos de neumonia, de los que 89 estaban causados por germenes atipicos. Los pacientes se dividieron retrospectivamente en 2 grupos segun el tratamiento empirico pautado: grupo A, al que se habia proporcionado cobertura frente a germenes atipicos (quinolonas o macrolidos), y grupo B, al que no se habia proporcionado dicha cobertura. Se estudio la evolucion segun las diferencias entre ambos grupos en la estancia hospitalaria, la resolucion radiologica, el reingreso e...

2006-01-01

Chernobyl accident: the crisis of the international radiation community

Bulk trade and maritime transport costs: the evolution of global markets

The information given in the present report about the Chernobyl accident and its radiological consequences indicates a serious crisis of the international radiation community. The following signs of this crises can be discerned: The international radiation community did not recognize the real reasons of the accident for a long time. It could not make a correct assessment of the damage to the thyroid of the affected populations of Belarus, Russia and the Ukraine. Up to present time it rejects the reliable data on hereditary malformations. It is not able to accept reliable data on the increase in the incidence in all categories of people affected by the Chernobyl accident. The international radiation community supported the Soviet authorities in their attempts to play down the radiological consequences of the Chernobyl accident for a long time. (author)

1998-03-01

Relationship between the electronic structure of passive films and the susceptibility to pitting corrosion of stainless steels; Relations entre la structure electronique des films de passivation formes sur les aciers inoxydables et la susceptibilite de ces derniers a la corrosion par piqures

Since the 1950s a transport revolution has occurred comparable to events in the late nineteenth century when sailing ships were replaced by steam vessels. Freight rates for bulk products have decreased 65-70% due to improved maritime technology, and formerly separate markets for bulk products have been unified globally. It is suggested that the low freight rates since the early 1980s will level out in future. Price peaks caused by political and military crises like the Korean war, the Suez crisis, OPEC I and OPEC II also seem to be of diminishing importance over time. The world market has become much less sensitive to external shocks due to alternative sources of supply and alternative transport routes. Examples are given from the coal, grain and iron ore international market. 62 refs., 24 figs., 4 tabs.

1996-03-01

Explosions of chaotic sets

The passive films formed on 316L stainless steel in various NaCl solutions have been investigated by capacitance measurements (Mott-Schottky). Pitting parameters have been determined using the galvano-kinetic polarisation method. The obtained results reveal the existence of a shallow and a deep donor level localised in the band gap of the semiconducting oxide film. These energy levels are due to iron ions in the tetrahedral and octahedral positions. It also appears that the participation of the deep donor level effects the electric field. The study developed allows us to compare characteristic parameters of the electronic structure of the passive film to those related to pitting susceptibility. (authors) 25 refs.

1998-04-01

Additional protocol between France, EURATOM and IAEA. 2001-2002 ordinary session. Project of law authorizing the ratification of the additional protocol to the agreement between France, the European Atomic Energy Community and the International Atomic Energy Agency relative to the application of warranties in France; Protocole additionnel entre la France, Euratom et l'AIEA. Session ordinaire de 2001-2002. Projet de loi autorisant la ratification du protocole additionnel a l'accord entre la France, la Communaute europeenne de l'energie atomique et l'Agence internationale de l'energie atomique relatif a l'application de garanties en France

Large-scale invariant sets such as chaotic attractors undergo bifurcations as a parameter is varied. These bifurcations include sudden changes in the size and/or type of the set. An explosion is a bifurcation in which new recurrent points suddenly appear at a non-zero distance from any pre-existing recurrent points. We discuss the following. In a generic one-parameter family of dissipative invertible maps of the plane there are only four known mechanisms through which an explosion can occur: (1) a saddle-node bifurcation isolated from other recurrent points, (2) a saddle-node bifurcation embedded in the set of recurrent points, (3) outer homoclinic tangencies, and (4) outer heteroclinic tangencies. (The term ``outer tangency'' refers to a particular configuration of the stable and unstable manifolds at tangency.) In particular, we examine different types of tangencies of stable and unstable manifolds from orbits of pre-existing invariant sets. This leads to a general theory that unites ...

2000-09-01

Natural gas integration in Latin America: end of a dream?

This additional protocol to the agreement between France, EURATOM and the IAEA aims at reinforcing the nuclear weapons non-proliferation regime. This protocol widens the field of competences of the IAEA with the supply of new information relative to: the civil nuclear cooperation between France and countries having no nuclear weapons in the domain of fuel cycle; the regular inspection of French nuclear facilities; the trade (import and export) of medium- or high-level radioactive wastes containing plutonium, highly enriched uranium or {sup 233}U, and the trade of some non-nuclear equipments or materials with countries having no nuclear weapons. The protocol defines also some practical dispositions relative to the delays and periodicity of controls, to the transmission of data, to the appointment of IAEA inspectors and their access to the facilities and sites considered. The list of the activities and equipments covered by the protocol are given in appendixes. (J.S.)

2002-07-01

Thermogravimetric and specific heat determinations of a commercial reconcentrated sample of ulexite, between room temperature and 1,000 degree centigree; Determinaciones termogravimetricas y de calor especifico de un concentrado comercial de ulexita, entre temperature ambiente y 1.000 grados centigrados

Throughout the 1990's to year 2000, energy integration, and particularly natural gas integration, was seen as a major goal in the southern cone of South America. The regional perspective for energy was related to an even more challenging objective - Latin American economic integration, which was quickly moving forward by the constitution of Mercosur, the free trade zone built by Argentina, Brazil, Uruguay and Paraguay, and also having Bolivia and Chile as special partners. Mercosur was getting stronger and becoming a successful political project. Trade conflicts existed, but they were considered normal and nobody would disagree about the viability of Mercosur. By the beginning of the 21. century, the economic integration process in South America was already advancing timidly as compared to the impetus from the beginning of 1990's. Mercosur started facing complex and almost insurmountable challenges after the numerous global financial crises (from 1998 to 2003) had ...

Prevalence and Predisposing Factors for Bundle Branch Block in Patients Starting Dialysis

The important amount of hydration water in the ulexite (NaCaN{sub 5}O{sub 9}.8H{sub 2}O), allows using calcination methods to increase its B{sub 2}O{sub 3} content. This paper analyses the thermal decomposition reaction of a preconcentrated ulexite through weight loss measurements, which occur during the heating of samples until 1000 degree centigree, Determinations of heat content at each temperature were made using an isoperibol calorimeter. The mean specific heat was calculated from these values, and its dependence on temperature was determined. The maximum weight loss was about 32.5% and the specific heat obtained was 1,13 kJ/kg 0 C for solid samples and 1,38 kJ/kg''0 C for fluid samples. The results are useful for the design of the industrial process, in order to determine the thermal requirements for heating calcined ulexite, and to obtain smelted ulexite. (Author) 19 refs.

2006-07-01

British Library Electronic Table of Contents (United Kingdom)

Introduccion y objetivos Aunque los bloqueos de rama (BR) se consideran hallazgos frecuentes, la informacion sobre su prevalencia real en la poblacion general es escasa, y es inexistente en los pacientes en dialisis. El objetivo es establecer la prevalencia del BR completo en la poblacion que inicia dialisis y los factores relacionados con su aparicion. Como analisis adicional, se explora su asociacion con la mortalidad y con la aparicion de un evento cardiovascular. Metodos Se incluyo a los pacientes que iniciaron dialisis en nuestro centro entre el 1 de noviembre de 2003 y el 31 de diciembre de 2006. Todos fueron sometidos a valoracion cardiologica al inicio de dialisis. Determinamos el BR y su relacion con factores clinicos y parametros ecocardiograficos y bioquimicos. Los pacientes fue...

2008-01-01

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P431 - Reaction hemolytique differee post-transfusionnelle chez une drepanocytaire

British Library Electronic Table of Contents (United Kingdom)

Une enfant drepanocytaire homozygote SS de 14 ans (sans deficit en G6PD), non transfusee anterieurement, a une cholecystectomie pour lithiase decouverte a un bilan systematique. L'intervention est encadree de 2 transfusions de concentres erythrocytaires (CGR) phenotypes ABO Rh Kell, compatibilises. Quinze jours apres, elle presente une hemolyse aigue associant fievre, ictere, insuffisance renale tubulaire, hemoglobinurie et anemie profonde (Hb 3,6 g/dL). Les RAI deviennent positives avec, entre autres, un auto anticorps anti D suspecte, le test de Coombs direct est positif de type mixte. L'enfant n'est pas retransfusee, mais recoit 1 mg/kg/j de corticoides IV pendant 10 jours. L'hemoglobine retrouve sa valeur de base (9 g/dL) apres 15 jours. Un antigene RH1(D) partiel de type DAR est ulter...

2010-01-01

Metastatic tumor of thoracic and lumbar spine: prospective study comparing the surgery and radiotherapy vs external immobilization with radiotherapy; Metastases do segmento toracico e lombar da coluna vertebral: estudo prospectivo comparativo entre o tratamento cirurgico e radioterapico com a imobilizacao externa e radioterapia

Law project adopted by the Senate and authorizing the ratification of the additional protocol to the agreement between France, the European atomic energy community and the international atomic energy agency relative to the application of warranties in France; Projet de loi adopte par le Senat autorisant la ratification du protocole additionnel a l'accord entre la France, la Communaute europeenne de l'energie atomique et l'Agence internationale de l'energie atomique relatif a l'application de garanties en Franc

Bone metastases at the thoracic and lumbar segment of the spine are usually presented with painful sensation and medullar compression. The treatment is based on the clinical and neurological conditions of the patient and the degree of tumor invasion. In the present study, 32 patients with spinal metastasis of thoracic and lumbar segment were prospectively analyzed. These patients were treated by decompression and internal stabilization followed by radiotherapy or irradiation with external immobilization. The election of the groups was in accordance with the tumor radiotherapy sensitivity, clinical conditions, spinal stability, medullar or nerve compression and patient's decision. The Frankel scale and pain visual test were applied at the moment of diagnosis and after 1 and 6 months. The surgical group had better results with preserving the ambulation longer and significant reduction of pain.(author)

2007-09-15

A method for the optimal design of networks of drinking water distribution; Un metodo para el diseno optimo de redes de distribucion de agua potable

This project of law concerns an additional protocol to the agreement of warranties signed on September 22, 1998 between France, the European atomic energy community and the IAEA. This agreement concerns the declaration of all information relative to the R and D activities linked with the fuel cycle and involving the cooperation with a foreign country non endowed with nuclear weapons. These information include the trade and processing of nuclear and non-nuclear materials and equipments devoted to nuclear reactors (pressure vessels, fuel loading/unloading systems, control rods, force and zirconium tubes, primary coolant pumps, deuterium and heavy water, nuclear-grade graphite), to fuel reprocessing plants, to isotope separation plants (gaseous diffusion, laser enrichment, plasma separation, electromagnetic enrichment), to heavy water and deuterium production plants, and to uranium conversion plants. (J.S.)

2002-10-01

First assessment of low- to medium-temperature geothermal reserves in 20 Mexican states; Primera estimacion de las reservas geotermicas de temperatura intermedia a baja en veinte estados de Mexico

A method to select, among several commercial diameter options, the most economic combination of pipeline networks is presented. These networks comply with the discharge conditions in the pipes and pressure in the knots. It is applied a static method for the hydraulics analysis of the Engineering Institute of the Universidad Nacional Autonoma de Mexico (UNAM) and an optimization technique to reduce the number of calculations. [Spanish] Se presenta un metodo para seleccionar, de entre varias opciones de diametros comerciales, la combinacion que forma la red de tuberias mas economica que satisface las condiciones de gasto en los tubos y de presion en los nudos de la misma. Para el analisis hidraulico se emplea un metodo estatico del Instituto de Ingenieria de la Universidad Nacional Autonoma de Mexico (UNAM) y se aplica una tecnica de optimacion para reducir el numero de calculos y alcanzar la solucion.

1998-12-01

The role of the state oil company in Latin America

A first, partial, assessment is included of the low- to medium-temperature geothermal reserves in 20 Mexican States and their aggregate value. The assessment covers about 29.16% of the identified geothermal-surface manifestations in the public database. For reserve assessments, we use the volumetric method, supplemented with Montecarlo simulations and statistics, to quantify inherent uncertainties. Our estimations are presented on a state-by-state basis. We estimate the aggregated reserves of the 20 states as between 7.7 x 1016 and 8.6 x 1016 kJ, with 90% confidence. The most likely reservoir temperatures range between 60-180 degrees Celsius, with a mean of 111 degrees Celsius. Such massive amounts of recoverable energy-and the associated temperatures-are potentially important for the economic development of nearby localities and the nation. [Spanish] En este trabajo se hace una primera estimacion, parcial, de las reservas geotermicas de temperatura intermedia a baja de Mexico. La ...

2009-07-15

Hot, flat and crowded. Why we need a green revolution - and how it can renew America

The role of the Latin American state oil companies (LASOCs) in establishing national industries to fuel economic development is discussed. LASOCs are represented internationally in an organization called ARPEL (Asistencia Reciproca Petrolera Estatal Latinoamericana) which is aimed to foster interchange, cooperation, and mutual assistance among its 20 member companies, as well as to promote economic integration of Latin America through its petroleum sector. State oil companies in Latin America date from 1922, when the oldest LASOC was created in Argentina. LASOCs are responsible for ca 80% of petroleum activities in Latin America. As of 1990, Latin American oil reserves, including gas liquids, amounted to ca 122 billion bbl or 12.2% of the world total. Regional oil production averaged 7.4 million bbl/d in 1990. Refining capacity is ca 7.7 million bbl/d, of which 80% is operated directly by LASOCs. Natural gas reserves are 7.3 trillion m"3, ca 6% of the world total, and production ...

DOE indirect liquefaction program

The author blows the whistle about what he considers as a worldwide environmental crisis. He brings a fresh outlook to the crises of destabilizing climate change and rising competition for energy - both of which could poison our world if we do not act quickly and collectively. His argument speaks to all of us who are concerned about the state of America in the global future. The author proposes that an ambitious national strategy - which he calls 'Geo-Greenism' - is not only what we need to save the planet from overheating; it is what we need to make America healthier, richer, more innovative, more productive, and more secure. He explains a new era - the Energy-Climate era - through an illuminating account of recent events. He shows how 9/11, Hurricane Katrina, and the flattening of the world by the Internet (which brought 3 billion new consumers onto the world stage) have combined to bring climate and energy issues to Main Street. But they have not gone very far ...

Computerized Tomography-guided fine-needle biopsy of peripheral pulmonary nodules < 2 cm in diameter

Processes for the hydrogenation of carbon monoxide have had commercial importance since about 1920, when the commercial production of methanol and higher alcohols on oxide catalysts began. Soon thereafter Fischer and Tropsch discovered that liquid hydrocarbons could be synthesized from carbon monoxide and hydrogen over Group VIII metal catalysts. Following extensive catalyst and process development efforts, this technology provided Germany with a source of liquid fuels during World War II. The period following the war saw an acceleration in research and development on the Fischer-Tropsch process, but the only commercial application that was to emerge was the SASOL process in the Union of South Africa. The oil crises of the 1970s have rekindled worldwide interest in indirect liquefaction technologies for the production of clean, high-quality motor fuels from coal. The development of more efficient coal gasification processes and the advent of molecular sieve ...

1985-01-01

Heat transfer equipment performance diagnosis of auxiliary systems in electric power stations; Diagnostico de comportamiento de equipo de transferencia de calor de sistemas auxiliares de centrales termoelectricas

The authors investigated the role of Computerized Tomography in guiding fine needle biopsy (FNB) in small (2 2 cm in diameter for CT-guided FNB sensitivity, specificity and diagnostic accuracy. Cytologic specimens were positive for malignancy in 40/52 cases (76.9%) and negative in 12 (23.1%). Clinical-surgical follow-up confirmed all the positive cytologic findings (40 cases), while 2 of the extant 12 cases were false negatives (95.20% sensitivity, 100% specificity and 96.15% diagnostic accuracy). 158 of 195 nodules > 2 cm in diameter and with clinical surgical follow-up (81.3%) were positive for malignancy and 34 were negative (17.43%) (98.75% sensitivity, 97.14% specificity and 98.46% diagnostic accuracy). Pneumothorax occurred in 33 patients (16.5%) with nodules > 2 cm in diameter as a complication of biopsy. Hemoptysis occurred in 15 patients (7.5%). In the whole group of lung lesions, the complications were pneumothorax in 80 patients (4.1%), hemoptysis in 199 (10.4%) and ...

Organizational models for new economy in the public and the private one; Modelli organizzativi per la new economy nel pubblico e nel privato

In this article the methodology followed to diagnose the performance of the equipment where heat is transferred from the feed water, condensate and circulation water systems in fossil power plants (FPP). The data collection is made with the unit in normal operation, using local instrumentation without taking the equipment out of service for its installation. The equipment diagnosis is made through the analysis of the collected data in actual operation and the design data; for this purpose a thermal balance of the interested systems is performed to obtain all the conditions an operation data. Later on the performance indicative parameters (PIP) of actual operation and design are calculated and compared one against the other. Such a comparison reveals the performance deterioration and the possible equipment faults. The data obtained and the supplementary information are stored in a data base whose objective is that Comision Federal de Electricidad has on hand a prompt access to them in ...

1990-12-31

The carbonate feedback system: interaction between stratigraphic accommodation, ecological succession and the carbonate factory; Le systeme de feed-back des carbonates: une interaction entre accomodation stratigraphique, succession ecologique et l`usine des carbonates

Historically the organizational models have followed an evolution that has underlined a parallel trend to the complexity of the market, introducing as different mechanisms of coordination. Up to yesterday the winning model it was that hierarchical that however it is not certainly immune from limits. Beginning from eight hundred and especially in the nine hundred experts of organization have studied an alternative or supplementary model to that hierarchical: the bureaucratic model. This last entrusts the organization of the firm to the norms and the procedures considering them like the best integrating mechanism of development of the organizations. Today it is not made that to speak of the model to net, but it would be a serious error if this had to a substitutive model thought of the precedents, that can work then without hierarchy and without alone procedures entirely thanks to the use of Internet. In the present job are individualized new models of management of the private firms and ...

2001-07-01

Subsidence monitoring in the Cerro Prieto geothermal field, B.C., Mexico; Monitoreo de la subsidencia en el campo geotermico de Cerro Prieto, B.C., Mexico

In this paper, the analysis of carbonate depositional systems, using high resolution sequence stratigraphy, studies the ratio between change in accommodation space and skeletal carbonate production. This approach establishes the concurrent change in nature of facies belts (expansion, retraction and type) and fossil communities, within the detailed time frame in accommodation. Carbonate production is generally considered to be a fairly simple function of environmental conditions such as climate and water depth. However, data from several case studies also show a covariance between change in stratigraphic architecture of carbonate systems (the seaward or landward stepping stacking patterns of stratigraphic units) and charge in facies. Case studies include Carboniferous algal mound development in the Paradox Basin (USA), Devonian stromatoporoid reef development in Alberta (Canada), and Cenomanian rudistid shoal development in Oman. The hypotheses are tested on cases taken from the ...

1996-12-31

Study of the distribution of gamma emitters radionuclides between a pollution abatement factory and its surrounding environment; Case of the water treatment plant of the Grand Caen district. Study report; Etude de la repartition de radionucleides artificiels emetteurs gamma entre une usine de depollution et son milieu environnant; Cas de la station d'epuration du District du Grand Caen. Rapport d'etude

Since 1977, precise leveling surveys have been carried out to determine whether there have been vertical terrain displacements and the subsidence speed rate in the Cerro Prieto Geothermal field area. The elevation contours for each leveling show since 1962 that there was a basin that involves the geothermal field. The differences in the last three levelings show a generalized subsidence between Cerro Prieto (BN 10049) and Imperial faults (BN CD-14). [Spanish] A partir de 1977 se realizan trabajos de nivelacion de precision, con el fin de conocer si existen desplazamientos verticales del terreno y cual es la velocidad de subsidencia que existe en el area del Campo Geotermico de Cerro Prieto. Las configuraciones de cotas para cada uno de los anos nivelados, muestran que desde 1962 existe una cuenca que incluye al campo geotermico; la diferencia de cotas obtenidas en las tres ultimas nivelaciones, indican una subsidencia generalizada entre la Falla Cerro Prieto (BN ...

1999-04-01

Fifteen years of seismic monitoring at the Las Tres Virgenes, BCS, geothermal field; Quince anos de monitoreo sismico en el campo geotermico de Las Tres Virgenes, BCS

Except nuclear industry, diverse structures (hospitals, of research or manufacturers) can have appeal to the use of radioisotopes conditioned under unsealed shape. Such practices lead to tolerate releases in environment in the respect of a statutory device. So the collective network can contain radioisotopes the future of which is going to depend partially on the cleaning applied to waste water. This study through the analysis of a concrete case, has for objective to inform about the future of gamma radioelements present in waste water treated by a wastewater treatment plant. The contamination of the network is essentially due to Tc{sup 99} and I{sup 131}, radioelements present whatever the working day and the hour considered. The total estimated in-load for a day is important, of the order of 4000 MBq for Tc{sup 99} and 15 to 300 MBq for I{sup 131}. The assessment of cleaning of the station shows that this one plays a role towards this pollution through these stages of treatment. ...

2007-07-01

Spectroscopic characterization and temporal dynamics of energy transfer process between Tm{sup 3+} -Ho{sup 3+} and Yb{sup 3+} -Tm{sup 3+} ions in LiYF{sub 4} and LiLuF{sub 4} crystals; Caracterizacao espectroscopica e dinamica temporal dos processos de transferencia de energia entre os ions Tm{sup 3+} -Ho{sup 3+} e Yb{sup 3+} -Tm{sup 3+} em cristais de LiYF{sub 4} and LiLuF{sub 4}

Seismic monitoring at the Las Tres Virgenes, BCS, geothermal field started in 1992 with an analog station of vertical components detecting a large number of earthquakes of varying magnitudes. In February 1993, a seismic network was installed, composed of six digital stations DR-2000-with S-6000 and S-5000 sensors and three registration channels (N-S, E-W and vertical). This was the basis for the development of a program to correct arrival-time data for P and S waves due to instrument drift. From January to April 1994 and May to August 1995, based on the 170 seismic events recorded, a velocity model was proposed. From December 1995 to July 1996, seismic data were processed and interpreted, and zones of occurrence were determined for events according to magnitude and the predominant noise in the field. From September 2003 to December 2004, 10 seismic stations (permanent and temporary) were installed and monitored and it was concluded the most active fault system was El Volcan. From ...

2009-07-15

The correlation between accelerated and field corrosion tests performed in carbon steel and weathering steel coupons, coated and non-coated; Correlacao entre ensaios acelerados e ensaios de campo em corpos-de-provas de aco carbono e aco patinavel, sem e com revestimento

In this work, we perform spectroscopic studies to characterize the energy transfer processes occurring in rare-earth doped lithium fluoride systems, aiming the optimization of the population inversion of these media. Yb{sup 3+} ion was used in order to probe the electron-phonon coupling in LiYF{sub 4}, LiGdF{sub 4} and LiLuF{sub 4} matrices. In these systems it was obtained the average phononenergy, the vibronic transition probability and Huang-Rhys coupling constant. These parameters are dependent on the crystal host and the LiLuF{sub 4} system presents excluded correlation effects, an electronic repulsion that weakens the vibronic coupling. The Tm:Ho:LiYF{sub 4} system was studied under diode laser pumping at 796 nm, aiming the 2 {mu}m emission optimization. The ideal conditions of concentration and laser power were determined favouring the latter emission. Upconversion processes of two photons were identified besides the energy transfer among ions. The dynamic processes of ...

2001-07-01

Nuclear emergencies and behavior of the people: a challenge

The performance of four different organic coating systems applied to carbon and weathering steel coupons has been assessed in this investigation. applied on the surface of carbon steel and weathering steel coupons. The coupons have been evaluated using five different tests, three field tests and two accelerated tests. The field tests were carried out at three atmospheric stations, located at COSIPA in Cubatao-SP, at Alto da Serra in Cubatao-SP and at Paula Souza in Sao Paulo city. The accelerated tests consisted of (a) exposure to alternate cycles of ultraviolet radiation/condensation combined with salt spray cycles (UVCON combined with Salt Spray) and of (b) exposure to alternate cycles of ultraviolet radiation/condensation combined with the Prohesion test. The performance of the coatings was assessed by visual observation and photographs, using a method based on ASTM D-610, ASTM D-714 and ASTM-1654 standards to rank them. The oxide phases formed on the surfaces of the non-coated ...

2002-07-01

New technology for the emulsification of petroleum residuals in water; Nueva tecnologia para la emulsificacion de residuales del petroleo en agua

Full text: The IRSN has been organizing enquiries with the French population about risk and risk perception for a long time. In 2002, a collaboration between the IRSN in France and the SCK.CEN in Belgium has been set-up to simultaneously (November 2002) organise this poll in both countries. In each country, a representative sample of the population (over 1000 participants per country) has been consulted by Computer Aided Personal Interviews of about 30 minutes with the professional help of commercial companies: BVA in France and Research International in Belgium. The enquiry yields a broad spectrum of interesting data; here only the results relevant for the emergency context will be presented. One should be aware that these data were collected in a 'normal' period; important differences in behaviour may occur given a serious crisis. A first finding is that more than half of the respondents are convinced that an accident as severe as the Chernobyl disaster may happen in their country as ...

2003-10-03

Importance of the planning activities, cutting, handling and analysis of the nuclei of oil well drilling; Importancia de las actividades de planificacion, corte, manejo y analisis de los nucleos de perforacion de pozos petroleros

It turns out of interest to Comision Federal de Electricidad and Petroleos Mexicanos to reduce costs of fuel oil, reducing the viscosity of the residues petroleum of high vacuum distillation emulsifying these with water. The parameters that define the characteristics of the emulsions are mainly the relation of their components, viscosity, size and drop distribution and its stability. The experimental work began producing emulsions in form of lots, using samples of approximately 500 milliliters of vacuum residue. In this first stage, at different concentrations, were examined eight different surfactants, as well as combinations among them, also seven different stabilizers were used. With these tests it has been managed to identify the concentrations, as well as the most adequate relations of surfactants and stabilizers for the production of emulsions of vacuum residues in water. The size and drop distribution has been determined by means of an optical LEICA microscope, model DMLS, that ...

2001-07-01