26 research outputs found
Propuesta de reducción de mermas basadas en los patrones de venta de productos de Pizza Hut (pasta, pizzas y bebidas) periodo octubre 2012 a marzo 2013 Chiclayo, Perú
En la presente tesis se busca identificar principalmente cuales son los patrones de venta de los productos de la tienda Pizza Hut Chiclayo en el periodo octubre 2012 – marzo 2013 para reducir las mermas en el almacén y mejorar así el manejo de insumos en la empresa. Esto permitirá conocer el tipo de gestión, detallar la participación en la venta de cada producto y analizar el control de mermas actual. Se realizará dicha investigación utilizando un análisis descriptivo de toda la información recopilada en este periodo de estudio, y se procederá a pasar dicha información a gráficos del programa Excel y tablas dinámicas para un mejor entendimiento en el proceso de análisis. En el primer capítulo se muestra la problemática real por la cual la empresa está pasando y al mismo tiempo como se llegara a la solución del problema. En el segundo capítulo se manifestó conceptos claves y teorías básicas para un mejor entendimiento; el tercer capítulo es la metodología utilizada para el desarrollo de esta investigación. En el cuarto y quinto capítulo se muestra el proceso actual de gestión y el procesamiento de base de datos de como se ha estado manejando el proceso de venta y desecho en el periodo de estudio, toda esta información se analizó y desarrolló en el transcurso de esta investigación. Y por último el sexto capítulo es la propuesta basada en conclusiones de acuerdo a lo investigado; esta propuesta se basa en ideas precisas las cuales se manifiestan como puntos clave en la investigación, permitiendo así la mejora continua para la parte administrativa de la empresa
In-air and in-water performance comparison of Passive Gamma Emission Tomography with activated Co-60 rods
Abstract A first-of-a-kind geological repository for spent nuclear fuel is being built in Finland and will soon start operations. To make sure all nuclear material stays in peaceful use, the fuel is measured with two complementary non-destructive methods to verify the integrity and the fissile content of the fuel prior to disposal. For pin-wise identification of active fuel material, a Passive Gamma Emission Tomography (PGET) device is used. Gamma radiation emitted by the fuel is assayed from 360 angles around the assembly with highly collimated CdZnTe detectors, and a 2D cross-sectional image is reconstructed from the data. At the encapsulation plant in Finland, there will be the possibility to measure in air. Since the performance of the method has only been studied in water, measurements with mock-up fuel were conducted at the Atominstitut in Vienna, Austria. Four different arrangements of activated Co-60 rods, steel rods and empty positions were investigated both in air and in water to confirm the functionality of the method. The measurement medium was not observed to affect the ability of the method to distinguish modified rod positions from filled rod positions. More extended conclusions about the method performance with real spent nuclear fuel cannot be drawn from the mock-up studies, since the gamma energies, activities, material attenuations and assembly dimensions are different, but full-scale measurements with spent nuclear fuel are planned for 2023
Improved Passive Gamma Emission Tomography image quality in the central region of spent nuclear fuel
Reliable non-destructive methods for verifying spent nuclear fuel are essential to draw credible nuclear safeguards conclusions from spent fuel. In Finland, spent fuel items are verified prior to the soon starting disposal in a geological repository with Passive Gamma Emission Tomography (PGET), a uniquely accurate method capable of rod-level detection of missing active material. The PGET device consists of two highly collimated detector banks, collecting gamma emission data from a 360 degrees rotation around a fuel assembly. 2D cross-sectional activity and attenuation images are simultaneously computed. We present methods for improving reconstructed image quality in the central parts of the fuel. The results are based on data collected from 2017 to 2021 at the Finnish nuclear power plants with 10 fuel assembly types of varying characteristics, for example burnups from 5.7 to 55 GWd/tU and cooling times from 1.9 to 37 years. Data is acquired in different gamma energy windows, capturing the peaks of Cs-137 (at 662 keV) and Eu-154 (at 1274 keV), abundant isotopes in long-cooled spent nuclear fuel. Data from these gamma energy windows at well-chosen angles are used for higher-quality images, resulting in more accurate detection of empty rod positions. The method is shown to detect partial diversion of nuclear material also in the axial direction, demonstrated with a novel measurement series scanning over the edge of partial-length rods.Peer reviewe
Experimental observation and analysis of the 3v(1)(Sigma g) stretching vibrational state of acetylene using continuous-wave infrared stimulated emission
Peer reviewe
Pump-tunable continuous-wave singly resonant optical parametric oscillator from 2.5 to 4.4 µm
STIMULATED INFRARED EMISSION OF CH NEAR 3000 cm^-^1 WITH CONTINUOUS-WAVE LASERS
Author Institution: Department of Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki, FinlandWe have constructed a sensitive experimental setup that can directly probe stimulated emission arising from ro-vibrational transitions within the ground electronic state in gaseous CH. The setup has been used to record spectroscopic data on both symmetric and anti-symmetric vibrational states. The symmetric states cannot be observed in standard one-photon absorption experiments except as hot bands. We can determine the energies of the transitions near 3000~cm^-^1 with an accuracy that is better than 0.005~cm^-^1. In practice, the accuracy is limited by our wavemeter. The system is based on a pump-probe setup of two narrow-line, continous-wave laser beams crossing inside a sample cell. The pump beam (around 13000~cm^-^1) excites the molecules and is frequency locked to the sample cell, which also acts as an optical resonator greatly amplifying the pump beam. The probe beam (near 3000~cm^-^1) is provided by an optical parametric oscillator. The intensity of the beam can vary slightly due to stimulated emission from the excited molecules as it makes a single pass through the sample cell. The stimulated emission is detected by repeatedly switching the pump beam on and off while measuring the intensity of the probe beam using phase-sensitive detection. Spectroscopic data are gathered by tuning the wavelengths of the beams