173 research outputs found

    Ion counting efficiencies at the IGISOL facility

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    At the IGISOL-JYFLTRAP facility, fission mass yields can be studied at high precision. Fission fragments from a U target are passing through a Ni foil and entering a gas filled chamber. The collected fragments are guided through a mass separator to a Penning trap where their masses are identified. This simulation work focuses on how different fission fragment properties (mass, charge and energy) affect the stopping efficiency in the gas cell. In addition, different experimental parameters are varied (e. g. U and Ni thickness and He gas pressure) to study their impact on the stopping efficiency. The simulations were performed using the Geant4 package and the SRIM code. The main results suggest a small variation in the stopping efficiency as a function of mass, charge and kinetic energy. It is predicted that heavy fragments are stopped about 9% less efficiently than the light fragments. However it was found that the properties of the U, Ni and the He gas influences this behavior. Hence it could be possible to optimize the efficiency.Comment: 52 pages, 44 figure

    Evaluation of Various Dynamic Issues During Transient Operation of Turbocharged Diesel Engine with Special Reference to Friction Development

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    Copyright © 2007 SAE International The modeling of transient turbocharged diesel engine operation appeared in the early seventies and continues to be in the focal point of research, due to the importance of transient response in the everyday operating conditions of engines. The majority of research has focused so far on issues concerning thermodynamic modeling, as these directly affect heat release predictions and consequently performance and pollutants emissions. On the other hand, issues concerning the dynamics of transient operation are often disregarded or over-simplified, possibly for the sake of speeding up program execution time. In the present work, an experimentally validated transient diesel engin

    Renewing Criminalized and Hegemonic Cultural Landscapes

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    The Mafia's long historical pedigree in Mezzogiorno, Southern Italy, has empowered the Mafioso as a notorious, uncontested, and hegemonic figure. The counter-cultural resistance against the mafiosi culture began to be institutionalized in the early 1990s. Today, Libera Terra is the largest civil society organization in the country that uses the lands confiscated from the Mafia as a space of cultural repertoire to realize its ideals. Deploying labor force through volunteer participation, producing biological fruits and vegetables, and providing information to the students on the fields are the principal cultural practices of this struggle. The confiscated lands make the Italian experience of anti-Mafia resistance a unique example by connecting the land with the ideals of cultural change. The sociocultural resistance of Libera Terra conveys a political message through these practices and utters that the Mafia is not invincible. This study draws the complex panorama of the Mafia and anti-Mafia movement that uses the ‘confiscated lands’ as cultural and public spaces for resistance and socio-cultural change. In doing so, this article sheds new light on the relationship between rural criminology and crime prevention policies in Southern Italy by demonstrating how community development practice of Libera Terra changes the meaning of landscape through iconographic symbolism and ethnographic performance

    Entwicklung bei Traktormotoren in den letzten 20 Jahren

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    Seit Ende der 1990er-Jahre gilt die EU-Abgasgesetzgebung auch für Nonroad-Fahrzeuge und somit für landwirtschaftliche Traktoren. Mit der schrittweisen Einführung der EU-Abgasstufen I bis IV mussten die Emissionen der dieselmotorischen Hauptschadstoffe Partikelmasse und Stickoxide in den mittleren und oberen Leistungsklassen bis heute um jeweils rund 95 % vermindert werden. Möglich war dies nur dank intensiver Weiterentwicklung der Motor- und Abgastechnologien. HAFL und KIT zeigen die Entwicklung sowie einige dahinterstehende technische Zusammenhänge am Beispiel eines klassischen Traktor-Dieselmotors auf

    Secretion of parathyroid hormone-related protein by bovine mammary cells in vitro

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    Mammary cells were isolated from lactating cows at 1 to 6 weeks after calving and evaluated for their ability to secrete PTHrP in vitro. The tissue was enzymatically digested to release glandular acini. The digested acini were cultured on thin (1.0 mm) or thick (2.5 mm) layers of collagen. The cultures containing thick collagen were detached and allowed to contract on day 6. The culture medium consisted of M199 with prolation (8 µg/ml), insulin (5 µg/ml), cortisol (5 µg/ml), and fetal bovine serum (15%). PTHrP production was measured by N-terminal RIA and bioassay (stimulation of adenylate cyclase in the ROS 17/2.8 cell line). Medium was collected at 2-day intervals for 14 days. The cells reached confluence at 4–6 days. PTHrP production was low at day 2 (<0.5 ng/ml), but increased to peak production (2–4 ng/ml) at approximately day 6–8 of culture and remained constant until day 14. Immunoreactive and bioactive PTHrP levels in the culture medium correlated well. The cultures produced high levels of lactoferrin (500 to 3000 ng/ml) and low levels of α s1 -casein (14 to 77 ng/ml).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41592/1/774_2006_Article_BF02375695.pd

    Valorisation of Biowastes for the Production of Green Materials Using Chemical Methods

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    With crude oil reserves dwindling, the hunt for a sustainable alternative feedstock for fuels and materials for our society continues to expand. The biorefinery concept has enjoyed both a surge in popularity and also vocal opposition to the idea of diverting food-grade land and crops for this purpose. The idea of using the inevitable wastes arising from biomass processing, particularly farming and food production, is, therefore, gaining more attention as the feedstock for the biorefinery. For the three main components of biomass—carbohydrates, lipids, and proteins—there are long-established processes for using some of these by-products. However, the recent advances in chemical technologies are expanding both the feedstocks available for processing and the products that be obtained. Herein, this review presents some of the more recent developments in processing these molecules for green materials, as well as case studies that bring these technologies and materials together into final products for applied usage
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