Celso Martínez Rivero

Radiative transition probabilities and oscillator strengths for 164 lines arising from 5s2ns, 5s2np, 5s2nd, 5s2nf, 5s2ng and 5s5p2 configurations of Sn II have been calculated. These values were obtained in intermediate coupling (IC) and using ab initio relativistic HartreeFock (HFR) calculations. We use for the IC calculations the standard method of least square fitting of experimental energy levels by means of computer codes from Cowan. The results of calculations for radiative transition probabilities are presented and compared with the experimental result presents in the literature and with other theoretical values. These values, although in general agreement with the rare experimental data, do present some noticeable discrepancies.

Semi-classical approximate values of the Stark parameters for several lines of Sn II are reported in this paper. They were calculated using a set of wavefunctions obtained from Hartree–Fock relativistic calculations. Stark widths for 80 lines of Sn II arising from ns 2S1/2, np 2P1/2, 3/2, nd 2D3/2, 5/2 and nf 2F5/2, 7/2 levels of Sn II have been calculated in this way. Stark widths are presented as a function of temperature for an electron density of 1017 cm−3. Our results are compared with available experimental data. Stark shifts of five lines with experimental value in the bibliography have been studied normalized to an electron density of 1017 cm−3. Common regularities for the Stark width of several lines of singly ionized tin have been discussed.

Polycrystalline LnAg(WO4)(MoO4) powders, with Ln = La to Lu and Y, have been obtained by ceramic method. Rietveld refinement for all compounds reveals that they present tetragonal symmetry, space group I41/a (No. 88), where the Ln3+/Ag+ ions are located in the 4a atomic positions, since the W/Mo are randomly distributed into 4b crystal sites. In these compounds, a and b lattice parameters take values between those corresponding to tungstate and molybdate compounds. A progressive decrease in the lattice parameters is observed in going from La to Lu derivatives as a consequence of the well-known lanthanide contraction.

The CMS drift tubes (DT) muon detector, built for withstanding the LHC expected integrated and instantaneous luminosities, will be used also in the High Luminosity LHC (HL-LHC) at a 5 times larger instantaneous luminosity and, consequently, much higher levels of radiation, reaching about 10 times the LHC integrated luminosity. Initial irradiation tests of a spare DT chamber at the CERN gamma irradiation facility (GIF++), at large (∼ O(100)) acceleration factor, showed ageing effects resulting in a degradation of the DT cell performance. However, full CMS simulations have shown almost no impact in the muon reconstruction efficiency over the full barrel acceptance and for the full integrated luminosity. A second spare DT chamber was moved inside the GIF++ bunker in October 2017. The chamber was being irradiated at lower acceleration factors, and only 2 out of the 12 layers of the chamber were switched at working voltage when the radioactive source was active, being the other layers in standby. In this way the other non-aged layers are used as reference and as a precise and unbiased telescope of muon tracks for the efficiency computation of the aged layers of the chamber, when set at working voltage for measurements. An integrated dose equivalent to two times the expected integrated luminosity of the HL-LHC run has been absorbed by this second spare DT chamber and the final impact on the muon reconstruction efficiency is under study. Direct inspection of some extracted aged anode wires presented a melted resistive deposition of materials. Investigation on the outgassing of cell materials and of the gas components used at the GIF++ are underway. Strategies to mitigate the ageing effects are also being developed. From the long irradiation measurements of the second spare DT chamber, the effects of radiation in the performance of the DTs expected during the HL-LHC run will be presented.

ABSTRACT Introduction: chemical Burns are serious injuries due to their high potential to cause local and systemic damage. They represent between 2.4% and 10.7% of the patients admitted to burn units, and have an associated mortality of 30%. The available literature on Latin America is scarce. Objective: the main objective of the study is to determine the epidemiological and clinical characteristics of patients with chemical burns treated at Hospital Universitario de Santander burn unit, in Bucaramanga, Colombia. Methods: this was an observational, descriptive, and retrospective study, which included patients who presented with burns by chemical agents between January 1, 2009 to December 31, 2014; 29 patients were included. Results: chemical burns accounted for 1.5% of all burns; 17 cases were male gender; all were II and III degree burns; total body surface did not exceed 25%. The most affected site was the upper limb; there was a greater association with work related accidents with 16 cases; acids were the principal chemical agent involved with 17 cases and there was encountered 5injuries by assault; 19 patients required surgical intervention. Conclusions: chemical burns represent a small but significant percentage of burns, there is a clear association to accidental situations due to lack of training in the proper handling of chemicals, raising the need for primary prevention measures. MED.UIS. 2016;29(1):11-6. Keywords: Epidemiology. Chemical burns. Burn Unit

El presente artículo tuvo como objetivo analizar las condiciones culturales y socioeconómicas de las caletas pesqueras artesanales en Yacila (Piura) y Carquín (Lima), Perú. Se empleó una metodología de carácter cualitativo y de revisión sistemática, tipo básica y con un diseño descriptivo. Como técnicas de investigación se emplearon el diagrama de PRISMA, la matriz de registro de artículos y una tabla de distribución de artículos por base de datos. En sus resultados se evidenció que la pesca artesanal es una actividad practicada por tradición, reproduciéndose de generación en generación como un fin sociofamiliar que se recrea por cotidianidad o presión familiar. Se concluyó que en las caletas de Yacila y Carquín, la pesca artesanal es realizada por familias; en su mayoría por personas del sexo masculino, quienes, para cubrir las necesidades económicas, y debido a la falta de oportunidades laborales, deciden convertirla en su fuente de ingresos, ya que la mayoría de pecadores artesanales no poseen un apoyo gubernamental que les permita acceder a una estabilidad laboral, un salario digno, asistencia médica y condiciones óptimas.

Transitions probabilities for several lines arising from excited levels of Ge I, Bi I, and Tl I have from determined from emission lines intensities in a hollow‐cathode discharge. These values were put on an absolute scale by using, were possible, the experimental lifetimes published by others authors. Oscillator strengths for several lines interest arising from some configurations and some levels radiative lifetimes of these elements have been calculated.

During the High Luminosity LHC, the Drift Tube chambers installed in the CMS detector need to operate with an integrated dose ten times higher than expected at the LHC due to the increase in integrated luminosity from 300 fb-1 to 3000 fb-1. Irradiations have been performed to assess the performance of the detector under such conditions and to characterize the radiation aging of the detector. The presented analysis focuses on the behaviour of the high voltage currents and the dose measurements needed to extrapolate the results to High Luminosity conditions, using data from the photon irradiation campaign at GIF++ in 2016 as well as the efficiency analysis from the irradiation campaign started in 2017. Although the single-wire loss of high voltage gain observed of 70% is very high, the muon reconstruction efficiency is expected to decrease less than 20% during the full duration of High Luminosity LHC in the areas under highest irradiation.

The hard scatter from initial state hadrons to final state partons at LHC is reviewed with 2010 integrated luminosity. Plots showing certain quantities are shown as well as the powerful software tools for describing expectations.

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

To sustain and extend its discovery potential, the Large Hadron Collider (LHC) will undergo a major upgrade in the coming years, referred to as High Luminosity LHC (HLLHC), aimed to increase its instantaneous luminosity, 5 times larger than the designed limit, and, consequently leading to high levels of radiation, with the goal to collect 10 times larger the original designed integrated luminosity. The drift tube chambers (DT) of CMS muon detector system is built to proficiently measure and trigger on muons in the harsh radiation environment expected during the HL-LHC era. Ageing studies are performed at the CERNs gamma ray irradiation facility (GIF++) by measuring the muon hit efficiency of these detectors at various LHC operation conditions. One such irradiation campaign was started in October 2017, when a spare MB2 chamber moved inside the bunker and irradiated at lower acceleration factors. Two out of twelve layers of the DT chamber were operated while being irradiated with the radioactive source and then their muon hit efficiency was calculated in coincidence with other ten layers which were kept on the standby. The chamber absorbed an integrated dose equivalent to two times the expected integrated luminosity of the HL-LHC. Investigation on the outgassing of cell materials and of the gas components used at the GIF++ are underway and strategies to mitigate the aging effects are also being developed. The effect of radiation on the performance of DT chamber and its impact on the overall muon reconstruction efficiency expected during the HL-LHC are presented.

THIS ARTICLE DESCRIBES THE CALCULATION OF A SUPPORTED SLAB, THE SPAN OF WHICH, COVERING OF REINFORCEMENT AND STRESSES ARE KNOWN. AN ATTEMPT IS MADE TO CALCULATE THE OPTIMUM STEEL CROSS-SECTION, THICKNESS AND TYPE AND TYPE OF CONCRETE FOR THE MINIMUM COST. A NUMBER OF TECHNICAL CONSTRAINTS (STRENGTH, MAXIMUM DEFORMATIONS, CONSTRUCTIONAL STANDARDS) ARE TO BE TAKEN INTO ACCOUNT. A COMPUTER IS USED TO TREAT THE ABOVE DATA AND OBTAIN A NUMBER OF POSSIBLE DESIGN COMBINATIONS. THIS REPORT WAS PRESENTED AT THE 3RD SEMINAR ON APPLICATION OF COMPUTERS TO CONSTRUCTION ENGINEERING, WHICH TOOK PLACE IN LA HABANA, IN NOVEMBER 1972.

ON PRESENTE ICI LE CALCUL D'UNE DALLE AVEC APPUIS, DONT ON CONNAIT LA PORTEE, L'ENROBAGE DES ARMATURES ET LES CONTRAINTES ET DONT ON RECHERCHE LA SECTION D'ACIER, L'EPAISSEUR, LES TYPES D'ACIER ET DE BETON, DANS DES CONDITIONS DE COUT MINIMUN. ON DONNE EGALEMENT LES RESTRICTIONS TECHNIQUES DEVANT ETRE IMPOSEES (RESISTANCE, DEFORMATIONS MAXIMUM, NORMES DE CONSTRUCTION) ET DONT CERTAINES SONT TIREES DES PROGRAMMES D'UN MINICALCULATEUR. DE CES DONNEES ET DES 4 INCONNUES, EN TENANT COMPTE QUE LES TYPES D'ACIER ET DE BETON CONSTITUENT UN NOMBRE REDUIT DE COMBINAISONS, ON TIRE UN GRAPHIQUE DES DEUX AUTRES VARIABLES POUR CHAQUE COMBINAISON. CETTE METHODE PRESENTE UN INTERET DANS LES PROBLEMES SIMPLES ET ASSEZ PARTICULIERS, CAR LE NOMBRE DE VARIABLES UTILISEES DOIT ETRE REDUIT. COMMUNICATION PRESENTEE LORS DU IIIEME SEMINAIRE D'APPLICATION DES ORDINATEURS A LA CONSTRUCTION, LA HAVANE, NOVEMBRE 1972.