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Messung des Wirkungsquerschnitts astrophysikalisch relevanter KernreaktionenTrompler, Erik January 2009 (has links)
Die 14^N(p,gamma)^15O-Reaktion ist die langsamste im Bethe-Weizsäcker-Zyklus des Wasserstoffbrennens und bestimmt dessen Rate. Der Wirkungsquerschnitt dieser Reaktion wurde in der Vergangenheit über einen weiten Energiebereich gemessen. Erneute, genauere Messungen im niederenergetischen Bereich hatten gezeigt, dass der Wirkungsquerschnitt um einen Faktor zwei niedriger ist als erwartet. Im Rahmen dieser Arbeit soll überprüft werden, ob sich das auch für höhere Energien bestätigt.
Hierzu wurden Messungen am Protonenstrahl des 3 MV Tendetron-Beschleunigers, Forschungszentrum Dresden-Rossendorf, durchgeführt. Zunächst wird eine experimentelle Kalibrierung der gamma-Nachweiswahrscheinlichkeit dreier comptonunterdrückter Reinstgermanium-Detektoren im energiebereich von 0,7 bis 12 MeV durchgeführt. Das Ergebnis wird mit der bisher simulierten Effizienzkurve verglichen. Dann wird im Energiebereich von 0,5 bis 1,5 MeV der Wirkungsquerschnitt für 14^N(p,gamma)^15O*(6.7929), das heißt für den Einfang in den vierten angeregten von 15^O bei 6.792 keV, bestimmt. Der Einfang in diesen Zustand trägt mehr als die Hälfte zum extrapolierten Wirkungsquerschnitt bei Energien wie im Inneren der Sonne bei.
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An Investigation of Target Poisoning during Reactive Magnetron SputteringGüttler, Dominik January 2009 (has links)
Objective of the present work is a broad investigation of the so called target poisoning during magnetron deposition of TiN in an Ar/N2 atmosphere. Investigations include realtime in-situ ion beam analysis of nitrogen incorporation at the Ti sputter target during the deposition process and the analysis of particle uxes towards and from the target by means of energy resolved mass spectrometry. For experiments a planar, circular DC magnetron, equipped with a 2 inch titanium target was installed in an ultrahigh vacuum chamber which was attached to the beam line system of a 5 MV tandem accelerator. A manipulator allows to move the magnetron vertically and thereby the lateral investigation of the target surface. During magnetron operation the inert and reactive gas flow were adjusted using mass flow controllers resulting in an operating pressure of about 0.3 Pa. The argon flow was fixed, whereas the nitrogen flow was varied to realize different states of target poisoning. In a fi?rst step the mass spectrometer was used to verify and measure basic plasma properties e.g. the residual gas composition, the behavior of reactive gas partial pressure, the plasma potential and the dissociation degree of reactive gas molecules. Based on the non-uniform appearance of the magnetron discharge further measurements were performed in order to discuss the role of varying particle fluxes across the target during the poisoning process. Energy and yield of sputtered particles were analyzed laterally resolved, which allows to describe the surface composition of the target. The energy resolving mass spectrometer was placed at substrate position and the target surface was scanned by changing the magnetron position correspondingly. It was found, that the obtained energy distributions (EDF) of sputtered particles are influenced by their origin, showing signi?ficant differences between the center and the erosion zone of the target. These results are interpreted in terms of laterally different states of target poisoning, which results in a variation of the surface binding energy. Consequently the observed energy shift of the EDF indicates the metallic or already poisoned fraction on target surface. Furthermore the EDF's obtained in reactive sputtering mode are broadened. Thus a superposition of two components, which correspond to the metallic and compound fractions of the surface, is assumed. The conclusion of this treatment is an discrete variation of surface binding energy during the transition from metallic to compound target composition. The reactive gas target coverage as derived from the sputtered energy distributions is in reasonable agreement with predictions from model calculations. The target uptake of nitrogen was determined by means of ion beam analysis using the 14N(d, )12C nuclear reaction. Measurements at varying nitrogen gas flow directly demonstrate the poisoning eff?ect. The reactive gas uptake saturates at a maximum nitrogen areal density of about 1.1016 cm-2 which corresponds to the stoichiometric limit of a 3 nm TiN layer. At sufficiently low reactive gas flow a scan across the target surface discloses a pronounced lateral variation of target poisoning, with a lower areal density in the target race track compared to the target center and edge. Again the findings are reproduced by model calculations, which confirm that the balance of reactive gas injection and sputter erosion is shifted towards erosion in the race track. Accomplished computer simulations of the reactive sputtering process are similar to Berg's well known model. Though based on experimental findings the algorithm was extended to an analytical two layer model which includes the adsorption of reactive gas as well as its different kinds of implantation. A distribution of ion current density across the target diameter is introduced, which allows a more detailed characterization of the processes at the surface. Experimental results and computer simulation have shown that at sufficiently low reactive gas flow, metallic and compound fractions may exist together on the target surface, which is in contradiction to previous simulations, where a homogeneous reactive gas coverage is assumed. Based on the results the dominant mechanisms of nitrogen incorporation at different target locations and at varying reactive gas admixture were identified.
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Annual Report 2008 - Institute of RadiochemistryViehweger, K., Richter, A., Foerstendorf, H. January 2009 (has links)
No description available.
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Fast Digitizing and Digital Signal Processing of Detector SignalsHannaske, Roland January 2009 (has links)
A fast-digitizer data acquisition system recently installed at the neutron time-of-flight experiment nELBE, which is located at the superconducting electron accelerator ELBE of Forschungszentrum Dresden-Rossendorf, is tested with two different detector types. Preamplifier signals from a high-purity germanium detector are digitized, stored and finally processed. For a precise determination of the energy of the detected radiation, the moving-window deconvolution algorithm is used to compensate the ballistic deficit and different shaping algorithms are applied. The energy resolution is determined in an experiment with γ-rays from a 22Na source and is compared to the energy resolution achieved with analogously processed signals. On the other hand, signals from the photomultipliers of barium fluoride and plastic scintillation detectors are digitized. These signals have risetimes of a few nanoseconds only. The moment of interaction of the radiation with the detector is determined by methods of digital signal processing. Therefore, different timing algorithms are implemented and tested with data from an experiment at nELBE. The time resolutions achieved with these algorithms are compared to each other as well as to reference values coming from analog signal processing. In addition to these experiments, some properties of the digitizing hardware are measured and a program for the analysis of stored, digitized data is developed. The analysis of the signals shows that the energy resolution achieved with the 10-bit digitizer system used here is not competitive to a 14-bit peak-sensing ADC, although the ballistic deficit can be fully corrected. However, digital methods give better result in sub-ns timing than analog signal processing.
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Steuerungsinstrumente des Energiemanagements in der VerwaltungGünther, Edeltraud, Friedemann, Julia 15 October 2008 (has links)
Im Rahmen des Projektes „Effektive Steuerung der Energieeinsparung in der Verwaltung“ wurden theoretische Konzepte zur Steuerung des Energieverbrauchs in Verwaltungen sowie vielfältige praktische Beispiele aus Kommunen und Unternehmen recherchiert und systematisiert. Das Projekt wurde im Zeitraum vom 01.10.2007 – 31.01.2008 auf Initiative der Stadtverwaltung Dresden durchgeführt und vom Lehrstuhl Betriebliche Umweltökonomie an der TU Dresden wissenschaftlich begleitet.... (Auszug aus "Zielstellung")
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Die Wandlung der Stadt Kattowitz von einer Industriestadt zu einem MusikkulturzentrumBula, Karol 19 December 2019 (has links)
No description available.
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Componentes del Diamante de Porter y su relación con la competitividad en la organización Clúster Enoturístico de Ica durante el 2021 / Components of the Competitive Diamond and its relationship with the competitiveness of the Ica Wine Tourism Cluster organization, year 2021.Carpio Amoroto, Ismael, Cruz Tica, Elizabeth Lucero 30 March 2022 (has links)
El presente trabajo de investigación analizó los componentes del Diamante de Porter y su relación con la competitividad de la organización Clúster Enoturístico Racimos del Sur. Este gremio pertenece al concepto general clúster enoturístico, que engloba a todas las empresas del rubro: restaurantes, hoteles, agencias de turismo y bodegas vitivinícolas de la región de Ica. Asimismo, este estudio es cuantitativo de tipo no experimental, transversal, correlacional y aplicado. Como objetivo general, buscó determinar si existe relación entre los componentes del Diamante de Porter y la competitividad de la organización Clúster Enoturístico de Ica Racimos del Sur durante el 2021. Para lograr este objetivo, se utilizó un cuestionario que mide la relación entre los componentes del diamante y la competitividad de la organización. Como modelos de estudio, se emplearon el diamante de la competitividad de Michael Porter y el Mapa de la Competitividad del Banco Interamericano de Desarrollo (BID). El corpus estuvo integrado por 15 empresas que conforman el Clúster Enoturístico de Ica. Los resultados demostraron una relación positiva de grado medio entre las variables de estudio. Esto comprueba que la relación es directa y significativa. Finalmente, se concluyó que existe una relación directa entre los componentes del diamante de Porter y la competitividad de la organización Clúster Enoturístico de Ica Racimos del Sur durante en el 2021. / The present research work analyzed the components of the Porter diamond and its relationship with the competitiveness of the Clúster Enoturístico Racimos del Sur organization. This guild belongs to the general wine tourism cluster concept, which encompasses all companies in the field: restaurants, hotels, tourism agencies and wineries in the Ica region. Likewise, this study is quantitative, non-experimental, cross-sectional, correlational and applied. As a general objective, it sought to determine if there is a relationship between the components of the Porter diamond and the competitiveness of the Ica Racimos del Sur Wine Tourism Cluster organization during 2021. To achieve this objective, a questionnaire was used that measures the relationship between the components of the diamond and the competitiveness of the organization. As study models, the competitiveness diamond of Michael Porter and the Competitiveness Map of the Inter-American Development Bank (IDB) were used. The corpus was made up of 15 companies that make up the Ica Wine Tourism Cluster. The results showed a positive relationship of medium degree between the study variables. This proves that the relationship is direct and significant. Finally, it was concluded that there is a direct relationship between the components of the Porter diamond and the competitiveness of the Ica Racimos del Sur Wine Tourism Cluster organization during 2021. / Tesis
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Plan de negocios de helados saludables: “Viking Healthy Ice Cream”Anchante Rasmussen, Carmen Antuanet, Enriquez Gomez, Bruno, Huamani Huamani, Emma, Gonzales del Valle Zuñiga, Renato, Ramos Canchumanta, Jersson 18 July 2021 (has links)
Nuestro proyecto de investigación es de Helados Artesanales con contenido proteico con la marca “Viking Healthy Ice Cream” elaborado artesanalmente con productos naturales, proteína en polvo y sin azúcares añadidos, que aporta y tiene un balance nutricional para las personas que cuidan de su cuerpo, hacen ejercicios y buscan un postre saludable.
Para ello usamos la metodología de investigación exploratoria y descriptiva, ya que buscamos conocer el mercado y describir el comportamiento del consumidor de comida saludable de lima metropolitana.
Realizamos entrevistas de profundidad y creamos una landing page para validar nuestra hipótesis
Luego de verificar nuestro público objetivo y ver la oportunidad de mercado, realizamos un plan de marketing en donde vimos el mercado objetivo y los planes comerciales, diseñamos el producto, verificamos el precio y la distribución, creamos el plan comunicacional y que medios digitales usaríamos, luego cuando realizamos el plan de operaciones verificamos la calidad y la distribución de nuestros productos, decidimos que nuestras operaciones se realizaran bajo el modelo de negocio de dark kitchen, esta novedosa idea nos ayuda a tener mayor rentabilidad y mejor servicio a través del delivery que nos ofrecen, avanzamos nuestro proyecto verificando los procesos empresariales, asimismo hicimos todo nuestro plan de RRHH y organigrama para contar con los colaboradores adecuados y el método de contratación, finalmente realizamos el proceso financiero lo cual nos valida la rentabilidad de nuestro proyecto. / Our research project is Artisan Ice Creams with protein content with the brand name "Viking Healthy Ice Cream" made by hand with natural products, protein powder and no added sugars, which provides and has a nutritional balance for people who take care of their body, they exercise and look for a healthy dessert.
For this we use the exploratory and descriptive research methodology, since we seek to know the market and describe the behavior of the consumer of healthy food from metropolitan lime.
We conduct in-depth interviews and create a landing page to validate our hypothesis
After verifying our target audience and seeing the market opportunity, we made a marketing plan where we saw the target market and business plans, we designed the product, we verified the price and distribution, we created the communication plan and what digital media we would use, Then when we carry out the operations plan we verify the quality and distribution of our products, we decide that our operations will be carried out under the dark kitchen business model, this novel idea helps us to have greater profitability and better service through the delivery that we offer, we advance our project by verifying the business processes, we also made our entire HR plan and organization chart to have the appropriate collaborators and the hiring method, finally we carry out the financial process which validates the profitability of our project. / Trabajo de investigación
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Regulation des Reduced Folate Carrier (RFC1) in HPCT-1E3-Ratten-Hepatocytoma-Zellen durch Cytochrom P450-Induktoren vom Phenobarbital-TypHalwachs, Sandra 06 July 2004 (has links)
The sodium dependent reduced folate carrier (Rfc1; Slc19a1) provides the major route for cellular uptake of antifolate chemotherapeutic drugs such as methotrexate (MTX) and reduced folates into liver, kidneys and other tissues. Despite its essential role in cancer treatment and for the body’s folate homeostasis, little is known about Rfc1 regulation. In rat hepatocytes, the 5´ untranslated region of this carrier exhibits, amongst other regulatory elements, a barbiturate recognition box which as yet has only been found in the promotor region of xenobiotic metabolizing enzymes, particularly those of the CYP450 enzyme family. We have therefore investigated the issue of Rfc1 regulation by phenobarbital (PB)-type CYP450 inducers on the functional, transcriptional and translational level using an adequate in vitro model for rat liver. A significant decrease in Rfc1 activity was observed following treatment (48 h) with 1-10 times therapeutic plasma concentrations of PB-type CYP450 inducers like PB, carbamazepine, chlorpromazine, clotrimazole and with the constitutive androstane receptor agonist TCPOBOP. This was not associated with reduced mRNA and protein levels. Further mechanistic investigations revealed that short-term treatment (2 h) of cells with protein phosphatase 2A inhibitor okadaic acid and proteinkinase C inductor PMA was related to a significant reduction of Rfc1 mediated MTX uptake. Finally, the reduction in Rfc1 activity caused by PB, TCPOBOP and PMA was almost completely reversed by simultaneous incubation with the specific PKC inhibitor bisindolylmaleimide. These results demonstrate, that clinical relevant concentrations of PB-type CYP450 inducers cause a significant PKC-dependent reduction in Rfc1 uptake activity on the posttranscriptional level.
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Micromotor-mediated sperm constrictions for improved swimming performanceStriggow, Friedrich, Nadporozhskaia, Lidiia, Friedrich, Benjamin M., Schmidt, Oliver G., Medina-Sánchez, Mariana 22 July 2022 (has links)
Sperm-driven micromotors, consisting of a single sperm cell captured in a microcap, utilize the strong propulsion generated by the flagellar beat of motile spermatozoa for locomotion. It enables the movement of such micromotors in biological media, while being steered remotely by means of an external magnetic field. The substantial decrease in swimming speed, caused by the additional hydrodynamic load of the microcap, limits the applicability of sperm-based micromotors. Therefore, to improve the performance of such micromotors, we first investigate the effects of additional cargo on the flagellar beat of spermatozoa. We designed two different kinds of microcaps, which each result in different load responses of the flagellar beat. As an additional design feature, we constrain rotational degrees of freedom of the cell’s motion by modifying the inner cavity of the cap. Particularly, cell rolling is substantially reduced by tightly locking the sperm head inside the microcap. Likewise, cell yawing is decreased by aligning the micromotors under an external static magnetic field. The observed differences in swimming speed of different micromotors are not so much a direct consequence of hydrodynamic effects, but rather stem from changes in flagellar bending waves, hence are an indirect effect. Our work serves as proof-of-principle that the optimal design of microcaps is key for the development of efficient sperm-driven micromotors.
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