Flow behaviour of carrot puree: modelling the influence of time,temperature and potato flakes addition

Rheological properties of carrot puree were investigated in the 1–1000 s^?1 shear rate range with the objective of modelling the influence of time, temperature and addition of potato flakes on the flow behaviour. Carrot puree exhibited a shear‐thinning behaviour that was well described by the Ostwald‐de Waele (Power Law) model with a flow behaviour index of 0.34 (±0.02) at 20 °C. The time‐dependent behaviour was characterised by a second‐order Structural Kinetic Model. The decay of the structural parameter with time was found to be independent of shear rate. The Arrhenius model was used to explain the effect of temperature in the range from 4 to 60 °C. The dry matter was increased by adding potato flakes (0–5%). A power law model (for the concentration) and the Arrhenius relationship (for the temperature) were combined to simultaneously describe the effects of temperature and concentration. This study provides essential data for equipment and process design.     

Environmental Factors and the Application of Hydrogen Peroxide for the Removal of Toxic Cyanobacteria from Waste Stabilization Ponds

Toxin-producing cyanobacteria constitute a serious threat to human and environmental health. It is thus essential that an effective treatment guarantees the removal of cyanobacteria from wastewater before its inclusion in water recycling or environmental flow. Hydrogen peroxide (H2O2) has been shown to induce cyanobacterial decay in laboratory cultures. However, its application for the removal of cyanobacteria from wastewater treatment ponds under environmental conditions has not been investigated. To examine the effects of environmental factors, field trials were performed at both the mesocosm and full-scale levels. The mesocosm trial was completed under field conditions of incident radiation, with various H2O2 concentrations. A concentration of 1.1×10-4??gH2O2/μg chl-a resulted in a 32% decrease in cyanobacterial concentration after 24?h, and this approximate concentration was then applied to a wastewater treatment pond in the full-scale trial. In the full-scale experiment, intense spatial and temporal monitoring of phytoplankton concentrations and temperature throughout the pond was performed. Cyanobacterial biomass was reduced by 57% and total phytoplankton biomass by 70% within 48?h of H2O2 addition. Mixing and radiation were shown to control the depth reached by H2O2 following addition to the ponds. The synergistic effect of H2O2 addition with environmental factors increased the effectiveness of cyanobacterial removal compared with laboratory experiments. The concentration of H2O2 required for the removal of cyanobacteria under field conditions may be decreased from laboratory studies by an order of magnitude.     

Right atrial and right ventricular transmural pressures in dogs and humans. Effects of the pericardium

BACKGROUND: To determine the transmural pressure-dimension relations of the right atrium (RA) and right ventricle (RV) before and after pericardiectomy, six open-chest dogs were instrumented with pericardial balloons placed over the RA and RV free walls. METHODS AND RESULTS: PA appendage dimensions and RV free-wall segment lengths were measured using sonomicrometry. Intact-pericardium RA and RV transmural pressures were calculated by subtracting the pericardial pressures (measured using balloons) from the cavitary pressures. Pooled data from six animals with pericardium intact indicate that at RA and RV cavitary pressures of 5, 10, and 15 mm Hg, RV pericardial pressure was 4.3 +/- 0.3, 8.6 +/- 1.0, and 13.3 +/- 1.5 mm Hg, respectively, and RA pericardial pressure was 4.8 +/- 0.3, 9.6 +/- 0.6, and 14.6 +/- 0.6 mm Hg, respectively (mean +/- SD). With calculated unstressed dimensions, the cavity dimension data were normalized to strain (in percent). We determined that in the dog, RV strain would increase by 14% and RA by 68% to maintain cavitary pressure at 10 mm Hg on pericardiectomy. To compare these results with clinical data, RV (n = 7) and RA (n = 6) transmural pressures were measured using balloons in patients (age, 19 to 76 years) undergoing cardiac surgery. RA transmural pressure of six patients was 1.0 +/- 1.5 mm Hg when central venous pressures (CVPs) ranged from 3 to 16 mm Hg. RV transmural pressure equaled 1.2 +/- 1.9, 2.3 +/- 1.9, and 3.4 +/- 2.0 mm Hg when CVP was 5, 10, and 15 mm Hg, respectively. CONCLUSIONS: Pericardial constraint (as evaluated by the ratio of pericardial to intracavitary pressures when CVP is 10 mm Hg) accounted for 96% of RA cavitary pressure in the dog and 89% in humans and at least 86% of RV cavitary pressure in the dog and 77% in humans.     

Deformation of Pores in Viscoplastic Soil Material

Changes in soil pore volume and shape in response to internal and external mechanical stresses alter key soil hydrologic and transport properties. The extent of these changes is dependent on details of pore shape and size evolution. We present a model for quantifying rates of deformation and shape evolution of idealized spheroidal pores as functions of macroscopic stresses and soil rheological properties. Previous solutions for shrinkage of spherical pores embedded in a viscoplastic matrix under isotropic stress were extended to spheroidal pore shapes and biaxial stresses using Eshelby’s classical theory. Bulk soil behavior was obtained from upscaling of detailed single pore deformation. Results show that pore closure rates increase with decreasing initial aspect ratio (i.e., oblate pores close faster than spherical pores), and with higher deviatoric stress. Incomplete pore closure is attributed to soil hardening due to pore shape accommodation under biaxial stresses. The model provides a means for approximating pore deformation as input to predictive models for soil hydraulic properties.     

Biased Language Use in Stereotype Maintenance: The Role of Encoding and Goals.

In 4 studies, the authors investigated the relative impact of biased encoding of information and communication goals on biased language use. A category label (linguistic expectancy bias, Study 1) or a group label (linguistic intergroup bias, Study 2) was presented either before or after a story that participants were asked to communicate. Biased language use only emerged when participants learned about the group membership of the actor or the category label before hearing the story. However, communication goals had an effect on language use at the retrieval stage, independent of encoding (Studies 3 and 4). Although communication goal effects seemed to overwhelm encoding effects, encoding still influenced language use under externally imposed time pressure (Study 3) and self-imposed time constraints (Study 4). This research reaffirms the importance of both cognitive and communicative processes in stereotype maintenance and highlights the conditions under which they each operate. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Moving Out of Home Ownership in Later Life: The Influence of the Family and Housing Careers

Home ownership is often regarded as the preferred housing tenure; however, situations in parallel life-course careers might make moving to a rental home necessary or attractive to home owners. Retrospective data from the SHARELIFE survey were used to study the short- and long-term impact of situations and disruptions in the family and housing careers on leaving home ownership at middle (45–64) and older ages (65–80) in Denmark, Sweden and the Netherlands. We found that directly after separation and widowhood, the likelihood of leaving home ownership was the greatest. However, more than 10 years after separation and widowhood, individuals were still significantly more likely to leave ownership than those in their first marriage. Furthermore, late first childbirth and early first-time home ownership were associated with lower chances of leaving home ownership. We conclude that situations and changes in family and housing careers have both a short-term and a long-term impact on the likelihood of moving out of home ownership.     

The arsenic for phosphorus swap is accidental, rather than a facultative one, and the question whether arsenic is nonessential or toxic is quantitative, not a qualitative one

Arsenic shares many physicochemical properties with phosphorus, so that arsenic can be taken up inadvertently by cells through the pathways for phosphorus. As a phosphate analog, arsenate competes with phosphate and enters cells via phosphate transporters. In the cell, arsenate can be recognized as a substrate by enzymes that usually use phosphate as a substrate. The phosphate for arsenate swap results in wasteful ‘futile cycles’ in metabolic pathways, uncoupled oxidative phosphorylation and extreme DNA instability. The disrupting metabolic effects of arsenic have an evolutionary meaning, so that all living organisms—from chemoautotrophic organisms that grow by reducing or oxidizing arsenic to metazoan—carry highly conserved arsenic resistance genes. Arsenic resistance can result from different strategies including selective transport to maximize phosphate uptake and minimize entry of arsenate, active transport to export arsenate, arsenic storage in specialized compartments, enzyme selectivity toward phosphate, and increased efficiency of DNA repair systems. None of these strategies is infallible, though, and susceptibility to arsenic toxicity varies between taxa in many orders of magnitude. Even arsenic-hypertolerant organisms will stop to grow and will eventually die when exposed to arsenic over species-specific resistance limits. The arsenic for phosphorus swap is an accidental one, it does not warrant a conclusion in favor of the essentiality of arsenic to life as we know it.     

Contactless magnetic transmission system: vibration control and resonance compensation

This work addresses the vibration control of a contactless magnetic transmission system. A learning controller is utilized in this work due to limited actuator bandwidth and uncertainties in the resonant frequencies. Performance of the controller is evaluated under self-resonance, forced oscillation, and transient response. Self-resonance is completely eliminated; while for forced oscillation, the disturbance is attenuated. Stabilization time of the transient response is also significantly reduced, thereby confirming the vibration suppression capabilities of the controller.     

Boolean operations for 3D simulation of CNC machining of drilling tools

This paper addresses the simulation of drilling tools CNC machining. It describes a novel approach for the computation of the boundary representation of the machined tools. Machining consists of a sequence of boolean operations of difference between the tool and the grinding wheels through time. The proposed method performs the dynamic boolean operations on cross sections of the tool and it reconstructs the 3Dmodel by tiling between the cross sections. The method is based on classical computational geometry algorithms such as intersection tests, hull computations, 2D boolean operations and surface tiling. This approach is efficient and it provides user control on the resolution of the operations.     

A method for the transformation of factors in factor analysis

A method is proposed for obtaining combinations of factors derived from a factor analysis characterized by a large number of near-zero loadings relative to the original variables. It differs from rotation of factors, which replaces r factors by an equal number, r, of differently oriented factors, in that each solution consists of a single direction in F variable space.