University of Graz

About: University of Graz is a education organization based out in Graz, Steiermark, Austria. It is known for research contribution in the topics: Population & Context (language use). The organization has 17934 authors who have published 37489 publications receiving 1110980 citations. The organization is also known as: Carolo Franciscea Graecensis & Karl Franzens Universität.

Diesel fuel derived from vegetable oils, III. Emission tests using methyl esters of used frying oil

Abstract: The preparation of methyl esters of used frying oil, available as waste from restaurants and households, is described. Fuel specifications of this fuel are given, and values for gaseous (HC, CO, NOx) and particulate emissions, measured with a vehicle powered by a turbocharged, direct injection diesel engine, are shown. The ester fuel shows slightly lower HC and CO emissions but increased NOx values compared with reference US-2D fuel. The particulate emissions, however, are significantly lower with used frying oil. Preliminary results of an engine road test are described.

Complex organic matter in Titan's atmospheric aerosols from in situ pyrolysis and analysis

Abstract: The Huygens probe landed on Titan on 14 January this year, and seven papers published in this issue record the encounter. They describe a world that resembles a primitive Earth, complete with weather systems and geological activity. The ‘Huygens on Titan’ section opens with an overview of the descent and landing and a News and Views piece. Tomasko et al. describe the dry riverbed and drainage channels seen during Huygens' descent, evidence that liquid methane falls as rain or erupts from cryovolcanoes, periodically flooding the surface. This paper includes the images used on the cover to the Huygens section. Niemann et al. measured the abundances of isotopes of argon, nitrogen and carbon in the atmosphere, and conclude that there is no evidence that Titan's methane comes from biological activity. Fulchignoni et al. obtained precise measurements of temperature and pressure from the upper atmosphere right down to the surface. On the way down Huygens recorded evidence for lightning. Zarnecki et al. report that the probe landed on a relatively smooth surface of icy grains with the consistency of wet clay or sand. Isral et al. report that the aerosols in Titan's clouds have solid cores made from complex organic molecules containing carbon and nitrogen. And Bird et al. found that on average Titan's winds blow in the same direction as the moon rotates, and that close to the surface these winds are very weak, travelling at around walking speed. Aerosols in Titan's atmosphere play an important role in determining its thermal structure1,2,3. They also serve as sinks for organic vapours4 and can act as condensation nuclei for the formation of clouds5,6, where the condensation efficiency will depend on the chemical composition of the aerosols5,7. So far, however, no direct information has been available on the chemical composition of these particles. Here we report an in situ chemical analysis of Titan's aerosols by pyrolysis at 600 °C. Ammonia (NH3) and hydrogen cyanide (HCN) have been identified as the main pyrolysis products. This clearly shows that the aerosol particles include a solid organic refractory core. NH3 and HCN are gaseous chemical fingerprints of the complex organics that constitute this core, and their presence demonstrates that carbon and nitrogen are in the aerosols.

Efficacy and safety of HOE 901 versus NPH insulin in patients with type 1 diabetes. The European Study Group of HOE 901 in type 1 diabetes.

Abstract: OBJECTIVE: HOE 901 (Hoechst Marion Roussel, Frankfurt, Germany) is a biosynthetic insulin with a prolonged action. The aim of this study was to compare the effect of the long-acting insulin analog HOE 901 with NPH insulin regarding glycemic control in patients with type 1 diabetes. RESEARCH DESIGN AND METHODS: A total of 333 type 1 diabetic patients were enrolled in this multinational parallel group trial. Subjects were randomized either to two different formulations of HOE 901 (the formulations differed only in zinc content) or to NPH insulin. The study was only partially blinded because patients can distinguish HOE 901 (a clear solution) from NPH (a cloudy suspension). In addition to premeal injections of regular insulin, patients received HOE 901 at bedtime or NPH once daily at bedtime or twice daily in the morning and at bedtime. RESULTS: Fasting plasma glucose levels were significantly lower with HOE 901 (-1.88 mmol/l. P = 0.0005) as were fasting self-monitored blood glucose levels (-0.80 mmol/l, P = 0.0020). HbA1c levels also showed a significant reduction with HOE 901 (-0.14%) versus NPH (P = 0.030). The overall frequency of hypoglycemia did not differ, but the frequency of nocturnal hypoglycemia was significantly (P = 0.0037) lower with HOE 901 (36 vs. 55%). However, this effect on nocturnal hypoglycemia was significant only versus NPH once daily not NPH twice daily. The pattern of adverse events and injection site reactions with HOE 901 was similar to that with NPH. CONCLUSIONS: This study indicates that HOE 901 achieves better control of fasting glucose and HbA1c levels over 4 weeks, and HOE 901 has a possible safety benefit in terms of nocturnal hypoglycemia.

Level-set function approach to an inverse interface problem

Abstract: A model problem in electrical impedance tomography for the identification of unknown shapes from data in a narrow strip along the boundary of the domain is investigated. The representation of the shape of the boundary and its evolution during an iterative reconstruction process is achieved by the level set method. The shape derivatives of this problem involve the normal derivative of the potential along the unknown boundary. Hence an accurate resolution of its derivatives along the unknown interface is essential. It is obtained by the immersed interface method.