Natural convection cooling of a hot vertical wall wet by a falling liquid film

The system studied is a plane channel in which one of the two vertical walls is kept at an arbitrary temperature profile and may be partially or completely wet by a falling liquid film, while the opposite wall is adiabatic. Air from the environment flows along the channel with a mass flow rate which depends on the balance between hydraulic resistances and buoyancy forces. These latter, in their turn, depend on the distribution of temperature and humidity (hence, density) along the channel and eventually on the heat and mass transferred from wall and film to the humid air.A simplified computational model of the above system was developed and applied to the prediction of relevant quantities, such as the total energy subtracted to the hot wall, as functions of the geometrical and physical quantities that characterize the problem (channel height and thickness, localized hydraulic resistance, hot wall temperature and its distribution, film flow rate, ambient air temperature and humidity). Conclusions were also drawn on the cooling strategy to be adopted in the case when only a limited amount of coolant is available.     

A self-report typology of behavioral adjustment for young children.

A large, national U.S. sample of children rated their own behavior and emotions using the Self-Report of Personality--Child version (SRP-C) of the Behavior Assessment System for Children (C. R. Reynolds & R. W. Kamphaus, 1992). Cluster analysis was used to group 4,981 self-reports (SRP-C) of children between the ages of 8 and 11 years. Theoretical and empirical considerations were used to identify a 10-cluster solution. Internal validation procedures revealed that the 10-cluster solution was well replicated by independently classifying 2 large subsamples of participants. External validation evidence revealed that only 2 of the 10 clusters could be differentiated by parent and teacher ratings of behavior problems. Peer ratings of social status and behavior, however, proved far better than adult ratings at differentiating the clusters. These findings suggest that the realm of intraindividual adjustment is not well understood by parents and teachers of these same children. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dynamics of soil salinity in the Canadian prairies: Application of singular spectrum analysis

We studied hidden periodicities and trends in the temporal dynamics of soil salinity in the Canadian prairies at a field scale. Singular spectrum analysis (SSA) was applied to time series of the groundwater depth (Dgw), total precipitation, groundwater electrical conductivity (ECgw), and soil electrical conductivity (ECe). We found that the temporal variability of soil salinity is determined by its seasonal and quasi-3-yr oscillations controlled by similar cycles of Dgw and ECgw, which are controlled by the precipitation. In the seasonal cycle, the system “precipitation – groundwater depth – groundwater salinity – soil salinity” proceeds as follows: The maximal level of the precipitation is reached in late May. The water table peaks 2 months after the maximal level of precipitation was reached. The seasonal oscillation of ECgw is in phase with that of Dgw. ECe peaks 1.5 months after the maximal level of ECgw was reached. In the quasi-3-yr cycle, ECe peaks about 14 months after the maximal rise of the groundwater. Most likely, this cycle of Dgw is a response to the 3-yr periodicity of the precipitation observed in the region. SSA is the effective tool to detect hidden oscillations in soil processes handling relatively short time series with missing records.     

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.     

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.     

Stable Alignment of Tautomers at Room Temperature in Porphyrin 2D Layers

A major challenge in molecular electronics is to develop logic devices based on a truly intramolecular switching mechanism. Recently, a new type of molecular device has been proposed where the switching characteristic is mediated by the bistability in the position of the two hydrogen atoms which can occupy different, energetically equivalent positions (tautomerization) in the inner cavity of porphyrins and naphthalocyanines. Up to now, such a reaction has only been exploited at low temperatures and induced or detected through atomic scale manipulation. In addition, the unpredictability of the tautomer orientation currently excludes molecular interconnection to functional electronic circuits. Here, full evidence is provided that, following a newly proposed growth strategy, 2D layers of metal‐free tetraphenylporphyrins (H₂TPP) show frozen tautomerization even at room temperature on macroscopic domains, with the H atoms aligned along a direction settled a priori. This behavior is ascribed to the buckling of the molecule, anchored to the substrate, which removes the degeneracy between the two tautomer alignments. On this basis, a new way to exploit uniaxially oriented H₂TPP tautomers in a first elementary logic device is proposed.