A Reduced Output Ringing CMOS Buffer

In a multichip module, the parasitic elements of the interconnections influence the performance of the devices enclosed in the package. Phenomena such as ground bounce, cross-talk, propagation delay, and over/undershoot will degrade the data signal integrity. This brief describes an output buffer structure, consisting of a double feedback loop. It reduces the oscillating behavior caused by parasitic elements in the data lines during the final phase of an output transition. The proposed structure employs simultaneous monitoring of the pad voltage and of the supplied current. Precise control of these parameters will reduce the sensitivity to reflection effects and inductive parameters of the package and printed circuit board tracks     

Deactivation of a Pt/Al2O3 catalyst during the oxidation of hexafluoropropylene

A 5% Pt/Al₂O₃ catalyst was exposed to hexafluoropropylene (HFP) at concentrations between 500 and 4,500 ppm in humid air at temperatures between 300 and 400°C. The catalyst was found to deactivate over all conditions investigated. Analysis of the catalyst following reaction exposure indicated that the catalyst support had been transformed to aluminum fluoride, and that virtually all of the support's surface area had been lost. The observed deactivation was attributed to degradation of the catalyst support, caused by a reaction between the alumina support and product hydrofluoric acid. Under some conditions, the rate of catalytic deactivation was found to be proportional to the number of moles of hexafluoropropylene reacted.     

Diseases of the Achilles tendon in dogs and cats

Dogs and cats rarely have problems with the Achilles tendon and if so, it usually results from a direct trauma. Prime area for injuries is the insertion on the tuber calcanei or directly proximal. One defers between complete and partial ruptures, acute and chronic injuries as well as displacement of the tendon of the superficial digital flexor muscle. In 38 cases (33 dogs and five cats) the clinical examination, radiology, ultrasonography and therapy are shown. Usually the clinical examination is sufficient for a diagnosis (hyperflexion of the hock and weight-bearing on the plantar surface of the metatarsus). The radiology primarily shows up abnormalities on the calcaneus, mineralisations of the tendon and allows the assessment of implants. Ultrasonography is the diagnostic imaging of choice for judgement of tendon diseases as well as the progress of their healing. Tendon suture is advisable if the rupture is open, fresh and/or complete and in cases of luxation of the superficial digital flexor muscle. Immobilisation of the tarsus in hyperextension seems to be of utmost importance no matter if an operative or conservative therapy is chosen.     

Barley β-Glucans-Containing Food Enhances Probiotic Performances of Beneficial Bacteria

Currently, the majority of prebiotics in the market are derived from non-digestible oligosaccharides. Very few studies have focused on non-digestible long chain complex polysaccharides in relation to their potential as novel prebiotics. Cereals β-glucans have been investigated for immune-modulating properties and beneficial effects on obesity, cardiovascular diseases, diabetes, and cholesterol levels. Moreover, β-glucans have been reported to be highly fermentable by the intestinal microbiota in the caecum and colon, and can enhance both growth rate and lactic acid production of microbes isolated from the human intestine. In this work, we report the effects of food matrices containing barley β-glucans on growth and probiotic features of four Lactobacillus strains. Such matrices were able to improve the growth rate of the tested bacteria both in unstressed conditions and, importantly, after exposure to in vitro simulation of the digestive tract. Moreover, the effect of β-glucans-containing food on bacterial adhesion to enterocyte-like cells was analyzed and a positive influence on probiotic-enterocyte interaction was observed.     

Time‐series models with an EGB2 conditional distribution

A time‐series model in which the signal is buried in noise that is non‐Gaussian may throw up observations that, when judged by the Gaussian yardstick, are outliers. We describe an observation‐driven model, based on an exponential generalized beta distribution of the second kind (EGB2), in which the signal is a linear function of past values of the score of the conditional distribution. This specification produces a model that is not only easy to implement but which also facilitates the development of a comprehensive and relatively straightforward theory for the asymptotic distribution of the maximum‐likelihood (ML) estimator. Score‐driven models of this kind can also be based on conditional t distributions, but whereas these models carry out what, in the robustness literature, is called a soft form of trimming, the EGB2 distribution leads to a soft form of Winsorizing. An exponential general autoregressive conditional heteroscedastic (EGARCH) model based on the EGB2 distribution is also developed. This model complements the score‐driven EGARCH model with a conditional t distribution. Finally, dynamic location and scale models are combined and applied to data on the UK rate of inflation.     

Films made from poly(vinyl alcohol‐co‐ethylene) and soluble biopolymers isolated from postharvest tomato plant

Blended films were obtained from polyvinyl alcohol‐co‐ethylene (EVOH) with 52 kDa weight average molecular weight (M_w) and three water soluble biopolymers isolated from exhausted tomato plants hydrolysates. Two biopolymers contained mainly polysaccharides and had 27 and 79 kDa M_w, respectively. The third contained mainly lignin‐like C moieties and had 392 kDa M_W. The films were fabricated with a biopolymer/EVOH w/w ratio ranging from 0.1 to 0.9. All blends had molecular weight and solubility which were substantially different from the starting materials. They were characterized for the chemical nature, and the thermal, rheological, and mechanical properties. Evidence of a chemical reaction between the biopolymers and EVOH was found. Generally, the films exhibited higher mechanical strength but lower strain at break then the neat EVOH. The best performing blended film was fabricated from the 27 kDa M_w polysaccharide. This contained less than 10% biopolymer. It exhibited 1043 MPa Young's modulus and 70% strain at break against 351 MPa modulus and 86% strain for neat EVOH. The results offer scope for investigating biopolymers sourced from other biowastes to understand more the reasons of the observed effects and exploit their full potential to modify or to replace synthetic polymers. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41935.     

Improving PCA‐based anomaly detection by using multiple time scale analysis and Kullback–Leibler divergence

The increasing number of network attacks causes growing problems for network operators and users. Thus, detecting anomalous traffic is of primary interest in IP networks management. In this paper, we address the problem considering a method based on PCA for detecting network anomalies. In more detail, this paper presents a new technique that extends the state of the art in PCA‐based anomaly detection. Indeed, by means of multi‐scale analysis and Kullback–Leibler divergence, we are able to obtain great improvements with respect to the performance of the ‘classical’ approach. Moreover, we also introduce a method for identifying the flows responsible for an anomaly detected at the aggregated level. The performance analysis, presented in this paper, demonstrates the effectiveness of the proposed method.Copyright © 2012 John Wiley & Sons, Ltd.