Low Cost NBTI Degradation Detection and Masking Approaches

Performance degradation of integrated circuits due to aging effects, such as Negative Bias Temperature Instability (NBTI), is becoming a great concern for current and future CMOS technology. In this paper, we propose two monitoring and masking approaches that detect late transitions due to NBTI degradation in the combinational part of critical data paths and guarantee the correctness of the provided output data by adapting the clock frequency. Compared to recently proposed alternative solutions, one of our approaches (denoted as Low Area and Power (LAP) approach) requires lower area overhead and lower, or comparable, power consumption, while exhibiting the same impact on system performance, while the other proposed approach (denoted as High Performance (HP) approach) allows us to reduce the impact on system performance, at the cost of some increase in area and power consumption

Last Progress in CdTe/CdS Thin Film Solar Cell Fabrication Process

AbstractIn the past, we described a dry process for the fabrication of CdTe/CdS thin film solar cells. In this process, most of the layers composing the cell, namely ITO, ZnO, CdS and back contact are deposited by sputtering and CdTe is deposited by close-spaced sublimation. The treatment of CdTe is done at 400°C, for 10-20minutes, without CdCl2, by using a Freon gas, dichlorofluoromethane, as a Cl supplier. Back contact is made by depositing onto a not-etched CdTe film surface a buffer layer of As2Te3, followed by a thin layer of Cu and Mo. Recently, we modified the Cl-treatment and we improved the quality of the back contact. Since dichlorofluoromethane is an ozone depleting agent and its use is now forbidden, we replaced it with a gas, like Ar, containing 4%HCl and mixing it with a Fluorine-containing gas, such as CHF3. Both these gases are not depleting agents and they aren't forbidden. By adjusting the relative amounts of the chemical species into this mixture, we got results which are very similar to those obtained with dichlorofluoromethane. Concerning the back contact, we discovered that, by using as a buffer layer As2Te3, or Bi2Te3 and by making an annealing in air at 200°C for 15-30minutes, a stable and ohmic contact, without any rollover in the solar cell I-V characteristic, is obtained

waste silica sources as heavy metal stabilizers for municipal solid waste incineration fly ash

Abstract The present work discusses a new method, based on the use of silica fume, for heavy metal stabilization. The inertization procedure is reported and compared with other technologies, involving the employ of amorphous silica as stabilizing agent for municipal solid waste incinerator fly ash treatment (i.e. colloidal silica and rice husk ash). The obtained final materials are characterized in terms of chemical composition and phase analysis. The reported method, realized at room temperature, employs all waste or by-product materials. As a consequence it appears to be economically and environmentally sustainable

Bilateral asymmetry of skin temperature is not related to bilateral asymmetry of crank torque during an incremental cycling exercise to exhaustion

© 2018 Trecroci et al. Although moderate relationships (|r|~0:5) were reported between skin temperature and performance-related variables (e.g., kinetic), it remains unclear whether skin temperature asymmetry reflects muscle force imbalance in cycling. Therefore, the aim of this study was to assess whether a relationship exists between kinetic and thermal asymmetry during a fatiguing exercise. Ten elite cyclists were enrolled and tested on a maximal incremental cycling test. Peak crank torques of both legs were obtained at the initial and final workload. Likewise, bilateral skin temperatures were recorded before and after exercise. Asymmetric indexes were also calculated for kinetic (AIK) and skin temperature (AIT) outcomes. The bilateral peak crank torques showed a larger difference at the final compared to the initial workload (p0:05). Additionally, trivial relationships were reported between AIK and AIT (-0:3<r<0:2) at the initial and final workload. The obtained results showed that changes in bilateral kinetic values did not reflect concurrent changes in bilateral skin temperatures. This finding emphasizes the difficulty of associating the asymmetry of skin temperature with those of muscle effort in elite cyclists. Lastly, our study also provided further insights on thermal skin responses during exhaustive cycling exercise in very highly-trained athletes

A Pressure-Induced Incommensurate Phase in Ammonium Hydrogen Oxalate Hemihydrate

We report evidence for the existence of a new incommensurate phase in a crystal of ammonium hydrogen oxalate hemihydrate. This phase is remarkable in two aspects: it exists only above a critical pressure Pc, and the incommensurate wave vector, which is parallel to the vector c* of the reciprocal lattice, has the largest variation ever reported, varying continuously from 0.147c* at 4.3 kbar to ~ 0.25c* at the maximum pressure (8 kbar) used to date

Discretized rotation has infinitely many periodic orbits

For a fixed k in (-2,2), the discretized rotation on Z^2 is defined by (x,y)->(y,-[x+ky]). We prove that this dynamics has infinitely many periodic orbits.Comment: Revised after referee reports, and added a quantitative statemen

Indirect Detection of Kaluza-Klein Dark Matter from Latticized Universal Dimensions

We consider Kaluza-Klein dark matter from latticized universal dimensions. We motivate and investigate two different lattice models, where the models differ in the choice of boundary conditions. The models reproduce relevant features of the continuum model for Kaluza-Klein dark matter. For the model with simple boundary conditions, this is the case even for a model with only a few lattice sites. We study the effects of the latticization on the differential flux of positrons from Kaluza-Klein dark matter annihilation in the galactic halo. We find that for different choices of the compactification radius, the differential positron flux rapidly converges to the continuum model results as a function of the number of lattice sites. In addition, we consider the prospects for upcoming space-based experiments such as PAMELA and AMS-02 to probe the latticization effect.Comment: 25 pages, 9 figures, LaTeX. Final version published in JCA

Anthropometric characteristic and running parameters: speed performance of children

This contribution deals with speed abilities of the pupils in short-distance runs in athletics. In scientific literature there are lots of studies that analyze speed performance in adults. These studies showed the correlation between speed and anthropometric measurements and between performance and indicators of speed (acceleration, frequency and length of steps). The aim of our study was the description of speed performance about children to verify similar relation as found in adults. We investigated speed abilities using the 50 m sprint test with standing start. The sample of subject consisted of 90 male and female pupils (45 male and 45 female) aged between 6 and 8 years old: beginner in athletic practice. We analyze performance with chronometers and photocells and we collected for each subject the anthropometric measurements (weight, height, torso and lower limb length), total time, intercepts every 10 meters and frequency of the step every 10 meters. The Anova 1 Way and Tukey-Kramer post hoc test was used to verify if the results were statistically significant among intercepts. In general, boys run faster than girl, total time decrease as the age increase and the interpretation and management of the effort in sprint change in the different age. Furthermore, the correlation between speed and anthropometric measurements were not always verified and the 20 meter cut-off was the general point where the run decreased. In conclusion, the performance in children could be improved using technical exercises about the support phases and educational approach to extend the effort

Correlation between cognitive functions and motor coordination in children with different cognitive levels

Cognitive development is related with central nervous system maturation and plays a crucial role for the definition of executive functions such as movement imagination, movement planning and problem-solving. In particular, executive functions are required during complex interactions between players/environment and are also fundamental for motor skills coordination. Although the complex interaction between cognitive and physical outcomes was recognized by several authors, few studies examined the magnitude of the relation between executive functions and motor development according to dif- ferent stages of cognitive maturation. Thus the aim was the assessment of the relationships between motor skills coordination and executive functions in children with different cognitive level. Ninety healthy male participants were involved in the study where children affected by Down syndrome were, also, recruited. The participants were divided into three groups according to classi- fication of Piaget: concrete, formal operational groups and Down syndrome individuals. Executive functions were assessed using a validated computerized battery tests while motor skills was evaluated using the K\uf6rperkoordinations Test f\ufcr Kinder. Analysis of variance by ranks (Kruskal-Wallis nonparametric test) and Mann-Whitney U pairwise comparisons with Dunn\u2019s correction for multiple contrasts were applied to assess the differences concerning the two kinds of outcome. The Pearson product-moment correlation coefficient was used to calculate the correlation between physical performance and the outcomes of the cognitive tests. A Spearman correlation was used to analyze the data when the assumption of normality was violated. The three groups showed differences in both executive functions and motor coordination outcomes. The highest number of significant correlations was found in the formal operational group (correlation coefficients ranging between 120.999 and 120.520, and between 0.970 and 0.759, all p values < 0.05) while a small number of correlations were found in the concrete operational group (correlation coefficients equal to 120.527, 120.461, 120.436 and 0.468, all p values < 0.05). No correlations between executive function and motor coordination were found in Down syndrome group. High executive function seems to affect the coordination skills