High fluence nitrogen implantation in Al/Ti multilayers

We have studied the effects of high fluence nitrogen ion implantation on the structural changes in Al/Ti multilayers, with the aim of achieving multilayered metal-nitrides. The starting structures consisted of 10 alternate sputter-deposited Al and Ti films, with a total thickness of 270 nm, on (100) Si substrates. They were implanted with 200 keV N-2(+), to 1 x 10(17) and 2 x 10(17) at/cm(2), the projected range being around half-depth of the multilayers. Structural characterization was performed by Rutherford backscattering, Auger electron spectroscopy and transmission electron microscopy. It was found that ion implantation to the higher fluence induces a full intermixing of Al/Ti layers, resulting in a multilayered structure with different content of Al, Ti and N. The applied method can be interesting for preparation of graded (AI,Ti)N multilayers, with a controlled content of nitrogen and a controlled level of Al-Ti intermixing within the structures. (C) 2008 Elsevier B.V. All rights reserved.9th European Conference on Accelerators in Applied Research and Technology, Sep 03-07, 2007, Florence, Ital

Response factors to pegylated interferon-alfa/ribavirin treatment in chronic hepatitis C patients genotype 1b

Hepatitis C virus infection is the most common chronic blood-borne infection and one of the most important causes of chronic liver disease. Knowing the predictors associated with pegylated interferon/ribavirin (PEG-IFN/RBV) combination therapy response is important for evidence-based treatment recommendations. The goal of this study was to identify host and viral factors of response to PEG-IFN/RBV treatment in chronic hepatitis C genotype 1b patients. We have examined the relationship between gender, age, level of alanine aminotransferase (ALT), viral load and liver fibrosis progression on therapy response. ALT level and viral load were evaluated before starting treatment with combination therapy. The elevated levels of ALT and route of HCV transmission were found to be significantly associated with the response to therapy in HCV-infected patients. Our findings may be useful for estimating a patient’s likelihood of achieving sustained viral response. [Projekat Ministarstva nauke Republike Srbije, br. OI 173049 i br. TR 37021

Experimental and simulation testing of thermal loading in the jet tabs of a thrust vector control system

The paper discusses the temperature changes in mechanical jet tabs in a system of rocket motor thrust vector control, estimated by the simulation and experimental tests methodology. The heat transfer calculation is based on complex computational fluid dynamics simulations of both the nozzle and external tab flows, as the comprehensive integral flow zones with high flow parameters gradients. Due to a complexity of the model for flow calculations, the experimental estimation of the calculated results is carried out. The temperature is measured by jet tabs embedded thermocouples, and conducted through the rocket motor static tests. A good agreement of the calculated and measured results is achieved. The main aim of the developed method is to establish an approved calculation tool for designing new TVC systems in order to avoid disadvantages due to overheating

On the ion irradiation stability of Al/Ti versus AlN/TiN multilayers

A comparative study of the structural changes induced in Al/Ti and AlN/TiN multilayers by argon ion irradiation is presented. The layers were deposited on Si substrates, by ion sputtering in case of pure metals, and reactive ion sputtering in case of metal-nitrides, to a total thickness of similar to 270 nm. The multilayered structures consisted of 10 alternative similar to 27 nm layers of each component. For ion irradiation, we used 200 keV Ar+ ions having a projected range around mid-depth of the multilayered structures. Implantations were performed at room temperature, to the fluences from 5 x 10(15) to 4 x 10(16) ions/cm(2). Structural characterization included Rutherford backscattering analysis and transmission electron microscopy. The obtained results demonstrate that AlN/TiN multilayered system exhibits a much higher irradiation stability compared to the Al/Ti system. In Al/Ti multilayers, we observe a progressed intermixing with increasing the ion fluence, the behavior being closer to the ballistic than to the thermal spike model. In AlN/TiN system, no interface mixing was registered for any of the applied irradiation fluencies. Different behavior compared to Al/Ti system is assigned to immiscibility of AlN and TiN. (C) 2008 Elsevier B.V. All rights reserved.18th International Conference on Ion Beam Analysis, Sep 23-28, 2007, Univ Hyderabad, Sch Phys, Hyderabad, Indi

Ion beam modification of structural and electrical properties of TiN thin films

A study of ion beam modification of structural and electrical properties of TiN thin films is presented. The layers were deposited by reactive ion sputtering on (100) Si and glass slide substrates to a thickness of similar to 240 nm. After deposition the structures were implanted with argon ions at 120 keV, to the fluences from 1 x 10(15) to 1 x 10(16) ions/cm(2). The ion energy was chosen to give the projected ion range within the deposited layers, to minimize the influence of the substrate on the induced structural changes. Structural analysis of the samples was performed by cross-sectional transmission electron microscopy, X-ray diffraction and Rutherford backscattering spectrometry. Electrical characterization included sheet resistivity measurements with a four point probe. It was found that the as-deposited layers have columnar structure, individual columns stretching from the substrate to the surface and being a few tens of nanometers wide.Ion irradiation rearranges their crystalline structure, which remains polycrystalline, but the columns are broken, and nanocrystals of the same phase are formed. The structural changes can be nicely correlated to the measured electrical resistivity. (C) 2008 Elsevier B.V. All rights reserved.9th European Conference on Accelerators in Applied Research and Technology, Sep 03-07, 2007, Florence, Ital

Data from: Plum germplasm in Croatia and neighbouring countries assessed by microsatellites and DUS descriptors

At a certain period during the last century, former Yugoslavia (which among others used to include Bosnia and Herzegovina, Croatia, and Serbia) was the biggest producer of plums in the world. Traditional plum cultivars, still grown in this region, represent a mixture of several species including: European plums (Prunus domestica L.), mirabelles (Prunus insititia var. syriaca (Borkh.) Koehne), and damsons (P. insititia L.). The basic problem with the utilization of this plum germplasm, either for cultivation or breeding purposes, is a lack of reliable pomology data or reference repositories that would enable positive identification of cultivars. In this study, 62 plum accessions (42 traditional Croatian accessions, six well-known traditional accessions collected from Serbia and Bosnia, and 14 international, reference cultivars) were assessed using microsatellite markers and distinctness, uniformity, and stability (DUS) plum descriptors. Nine primer pairs amplified 168 distinct alleles, or on average 18.7 alleles per locus. A significant differentiation between the traditional plum cultivars and international reference cultivars, was detected through Fst (Fst = 0.022; P < 0.0001), analyses of molecular variance (AMOVA; f CT = 0.054; P < 0.05) and later confirmed by a factorial correspondence analysis (FCA). Bayesian method enabled the classification of mirabelle, damson, and European plum genotypes. Principal component analyses, based on 22 morphologic traits, managed to separate mirabelle accession from the European plum and damson accessions, but there was a general lack of correlation between the observed morphologic traits and the molecular data. Results of this study indicate that traditional Croatian accessions represent a diverse and underutilized plant genetic material, which should be conserved