614 research outputs found
Skin toxicity after radiotherapy. About a case
A 60-year-old woman was admitted to the Department complaining of a slow growing mass in the right knee. Physical examination demonstrated a mass on the postero-lateral aspect of the right knee, which was not tender or mobile, however was rubbery and hard in consistency. Full flexion and extension was observed without any restriction of joint movement
Steady state fluctuation relations for systems driven by an external random force
We experimentally study the fluctuations of the work done by an external
Gaussian random force on two different stochastic systems coupled to a thermal
bath: a colloidal particle in an optical trap and an atomic force microscopy
cantilever. We determine the corresponding probability density functions for
different random forcing amplitudes ranging from a small fraction to several
times the amplitude of the thermal noise. In both systems for sufficiently weak
forcing amplitudes the work fluctuations satisfy the usual steady state
fluctuation theorem. As the forcing amplitude drives the system far from
equilibrium, deviations of the fluctuation theorem increase monotonically. The
deviations can be recasted to a single master curve which only depends on the
kind of stochastic external force.Comment: 6 pages, submitted to EP
Asymptotic expressions of mismatch variance in interdigitated geometries
Performance in analog integrated circuits strongly depends on the mismatch between nominally identical devices. In this work we derive closed-form asymptotic expressions describing mismatch variance in multifinger structures, under the assumption of Gaussian autocorrelation for the mismatch-generating stochastic process. The analysis is performed on interdigitated geometries, eventually modified to make them common-centroid. Comparison with the numerical results provided by an independent model validates the theoretical expressions presented here
An experimental-numerical methodology for the nondestructive assessment of the dynamic elastic properties of adhesives
In the last years, lightweight design has become a priority in many industrial sectors, like as the aerospace and the automotive industry, mainly due to the strict regulations in terms of gas emission and pollution. Together with lightweight materials, the use of adhesives to join different parts permits to significantly reduce the weight of mechanical assemblies. For a proper design of the joints, the mechanical properties of adhesives should be correctly experimentally assessed. However, the experimental assessment of the adhesive mechanical properties can be complex, since they can be hardly estimated from traditional experimental tests on lap joint or butt-joint specimens. The development of an experimental procedure for the assessment of the adhesive properties is therefore of interest. In the present paper, a methodology for the assessment of the dynamic elastic properties of adhesives, i.e., Young's modulus and the loss factor, is proposed. The procedure is based on the Impulse Excitation Technique and Finite Element Analyses (FEA). An automated routine has been written to assess the elastic properties by minimizing the difference between the frequency response obtained experimentally and through FEA. The proposed methodology has been experimentally validated to estimate the mechanical properties of an epoxy adhesive for automotive applications
Stability and mismatch robustness of a leakage current cancellation technique
Leakage discharge currents represent one of the most detrimental factors for the maximum hold time in analog sample-and-hold circuits. Apart from the obvious passive solution of enlarging the sampling capacitor, alternatives based on active circuits have been proposed. We focus here on an existing solution which has proven to be effective in reducing the leakage discharge, hence extending the hold time, by a factor of 20. Being based on a feedback circuit built around the hold capacitor, it is paramount to understand its stability properties. This work tries to close the gap by analyzing the closed-loop stability of the nominal circuit. Classical control systems techniques are employed to thoroughly analyze the dynamic behaviour of the feedback circuit, highlighting the detrimental effect of device mismatches
Short communication: Jenny milk as an inhibitor of late blowing in cheese: A preliminary report
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An architecture for ultra-low-voltage ultra-low-power compressed sensing-based acquisition systems
Compressed Sensing (CS) has been addressed as a paradigm capable of lowering energy requirements in acquisition systems. Furthermore, the capability of simultaneously acquiring and compressing an input signal makes this paradigm perfectly suitable for low-power devices. However, the need for analog hardware blocks makes the adoption of most of standard solutions proposed so far in the literature problematic when an aggressive voltage and energy scaling is considered, as in the case of ultra-low-power IoT devices that need to be battery-powered or energy harvesting-powered. Here, we investigate a recently proposed architecture that, due to the lack of any analog block (except for the comparator required in the following A/D stage) is compatible with the aggressive voltage scaling required by IoT devices. Feasibility and expected performance of this architecture are investigated according to the most recent state-of-the-art literature
Effects of plasma treatments of polypropylene adhesive joints used in the automotive industry
Plasma treatment has been used in recent years to activate the surfaces of adhesive substrates and thus as an adhesion promoter between adhesive and substrates. The use of plasma treatments is widely adopted in the automotive industries especially for polymers that present low surface energy, such as polypropylene. In this work, polypropylene substrates used in the automotive industries have been treated with two different techniques: vacuum and atmospheric plasma. Then, polyurethane and methacrylate adhesives have been used to bond single lap joints (SLJs). Typically, these two adhesives cannot bond polypropylene substrates without surface treatments. An experimental plan has been designed to investigate the process parameters that can increase the functional polar groups (FPGs) maximizing the adhesion strength. Besides the types of plasma, two different gas carriers (air and nitrogen) and different treatment times have been investigated. The substrates, treated and not treated, have been assessed through scanning electron microscopy, energy-dispersive X-ray analysis, and Fourier-transform infrared spectroscopy to quantitatively assess the increment of FPGs after the different treatments. The experimental plan shows that the atmospheric plasma can improve the surface of the substrates by using a smaller time. Mechanical tests on SLJs show that methacrylate and polyurethane cannot bond polypropylene substrates without the plasma treatment. On the other hand, the treated substrates can form a strong bonding with the adhesive since all SLJs exhibit a substrate failure. Mechanical tests have been also carried out after three different aging cycles showing that the adopted plasma treatment is not affected by the aging cycles
Evaluation of Common Bean Varieties for Yield and Yield Component in Segen Area Peoples Zone SNNPRS, Ethiopia
Studies on the evaluation of variety performance provide opportunities to increase productivity of common bean. Therefore, the current study evaluates the performance of varieties on yield and yield components of common bean during the main cropping season of 2015 and 2016 at four locations in Segen Zone,Konso woreda (Southwestern Ethiopia) with the objectives of  selecting high yielding common bean varieties those are adapted to the study area. Fifteen released common bean varieties and one local cultivar were planted in randomized complete block design with three replications. The analysis revealed that significant variation for all traits except maturity date. Highest yield obtained from Nasir(2136 kgha-1) and Hawassa dume (1948 kgha-1) followed by Sari (1751 kgha-1) were as at Addis Gebere, high grain yield was obtained from Sari (2227 kgha-1), Hawassa dume (2111 kgha-1) and Dimtu (2073 kgha-1). For average mean yield from overall location, high yield obtained from Hawassa dume (2129 kgha-1) and Nasir (2002 kgha-1) followed by Sari (1989 kgha-1). Results revealed that Hawassa dume, Nasir and Sari were best performed and better adapted varieties than the others respectively. Therefore, the above mentioned varieties are promising varieties for the production area and recommendable for area with similar agro-ecologies. Keywords: Phaseolus Vulagris L, Evaluation, Grain yield,Varieties
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