196,318 research outputs found
Preface for Proceedings of SIMS XVIII, Riva del Garda, Italy, 2011
No full textNo abstract is available for this article
A comparison between mass spectrometry techniques on oxynitrides
No full textThe development of materials and processing in microelectronics needs an increasing parallel improvement of the analytical methodologies, required to geve up-to-date answers to the state of the art in this field. Oxynitride is a typical example. This material has replaced thermal silicon oxide as gate insulator due to the properties of good masking against impurity diffusion, together with the excellent dielectric strenght and the better resistance to dielectric breakdown. These properties allow the manufactoring of gate oxide with a thickness below 80 Å. In this work we present the application of analytical methodologies based on mass spectrometry on oxynitrides. In order to develope a complete analytical methodology, the influence of impact energy and incidence angle on the profile quantification in SIMS analyses has been investigated. Also a comparison between ToF-SIMS and SIMS analyses has been performed, to evaluate the applicability of ToF-SIMS depth profiling to this topi
Ambient Gas Induced SiC-like Structures in Edge-Defined Film-Fed Growth Polycrystalline Silicon Samples
No full textCorrelation between microstructure and SIMS analyses of cast irons incoulated with CG alloy
No full textRobust treatment planning with 4D intensity modulated carbon ion therapy for multiple targets in stage IV non-small cell lung cancer
No full textIntensity modulated particle therapy (IMPT) with carbon ions can generate highly conformal treatment plans; however, IMPT is limited in robustness against range and positioning uncertainty. This is particularly true for moving targets, even though all motion states of a 4DCT are considered in 4D-IMPT. Here, we expand 4D-IMPT to include robust non-linear RBE-weighted optimization to explore its potential in improving plan robustness and sparing critical organs. In this study, robust 4D-optimization - based on worst-case optimization on 9 scenarios - was compared to conventional 4D-optimization with PTV margins using 4D dose calculation and robustness analysis for 21 uncertainty scenarios. Slice-by-slice rescanning was used for motion mitigation. Both 4D-optimization strategies were tested on a cohort of 8 multi-lesion lung cancer patients with the goal of prioritizing OAR sparing in a hypofractionated treatment plan. Planning objectives were to keep the OAR volume doses below corresponding limits while simultaneously achieve CTV coverage with D95% ≥ 95 %. For the conventional plans, average D95% was at 98.7% which fulfilled the target objective in 83.2% of scenarios. For the robust plans, average D95% was reduced to 97.6% which still fulfilled the target objective in 80.7% of cases, but led to significantly improved overall OAR sparing: Volume doses were below the limits in 96.2% of cases for the conventional and 99.5% for the robust plans. When considering the particularly critical smaller airways only, fulfillment rates could be increased from 76.2% to 96% for the robust plans. This study has shown that plan robustness of 4D-IMPT could be improved by using robust 4D-optimization, offering greater control over uncertainties in the actual delivered dose. In some cases, this required sacrificing target coverage for the benefit of better OAR sparing
Sustainable methods to control Pyricularia oryzae, the causal agent of rice blast disease.
No full textBy 2030, global rice production will need to increase to meet the demand of the growing world population. However, rice is severely affected by blast disease caused by the fungus Pyricularia oryzae, which accounts for 10-30% yield losses per year globally, thus posing a threat to the world’s most important food crop. The fungus can infect all parts of the rice plant, including leaves, nodes and pani-cle. In the early stages of the infection process, P. oryzae forms an infection struc-ture called appressorium to break the plant cuticle. After an initial biotrophic phase, the fungus kills plant cells thus leading to visible symptoms.
Currently, several methods for the management of rice blast disease, such as agronomic practices, use of resistant cultivars and synthetic fungicides, are avail-able and can be exploited in an integrated management approach. However, de-spite some resistant rice varieties that have been developed by breeding pro-grams, P. oryzae is able to rapidly develop new races that overcome resistance genes. Furthermore, the continuous use of fungicides may be harmful to humans and environment and can increase the risk of appearance of resistant fungal races. Biological control using microbial agents or plant extracts with antimicrobial ac-tivity is therefore considered a possible alternative and sustainable approach to control rice blast disease. However, biological protection is difficult to achieve in the field as its effectiveness is variable, highly depending on formulations and climatic conditions. Because of these drawbacks, durable control of rice blast still represents a substantial challenge. Innovative strategies for the identification of new molecules for the sustainable protection of rice are thus highly desirable
Boron Ultra Low Energy SIMS Depth Profiling Improved by Rotating Stage
No full textOptimization of oblique incidence ultra low energy O2+ SIMS analysis of ultra shallow boron distributions has been investigated varying the atmosphere in the analysis chamber (ultra high vacuum or oxygen flooding) and evaluating the effect of a rotating stage allowing a 20 rpm rotation during the analysis. The impact of the different analytical approaches to the ripple formation on the crater bottom has been investigated on a boron delta doped silicon sample by AFM analysis. The combined use of a 0.5 keV O2+ beam at 68° of incidence with oxygen flooding and stage rotation of 20 rpm gave a decay length of 2.0 nm/decade at 60 nm depth without any appreciable detection of variation of sputtering rate
Tof-SIMS and XPS surface characterization of novel-perfluoropolyether-uretane ionomers from acqueous dispersions
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