Political Radicalization as a Communication Process

Based on data taken from 412 adult education students in Montreal, Quebec, Canada, this research attempts to show that attitudes toward French Canadian Separatism by the sample members can be accounted for by differentiaf communication processes. Results show that attitudes held by sample members are well explained (R2 = .64) by a weighted average of the information they received from interpersonal and media sources. The resultant attitude shows substantial effects on behaviors related to separatism for the same respondents.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67215/2/10.1177_009365027400100301.pd

Frictional losses and convective heat transfer in sparse, periodic cylinder arrays in cross flow

A numerical study of fluid flow and heat transfer around periodic cylinder arrays under laminar cross flow conditions is presented. The investigation considers flow in sparse square and traingular arrays, with fluid fractions ranging from 0.90-0.99 and particle Reynolds numbers from about 3-160. Volume averaging of the microscopic flow field variables is used to ascertain the functional form of coefficients appearing in the macroscopic (porous media) equations. Frictional losses are shown to follow Darcy's law when the Darcian Reynolds number is of the order of one, while significant non-Darcy effects are seen at higher Reynolds numbers. The validity of the Forchheimer and Ergun correlations is shown to be suspect for flow in this highly porous media. Local thermodynamic equilibrium is relaxed in order to explore cylinder-to-fluid convective heat transfer. Power-law relationships for frictional losses and Nusselt number are shown to correlate well with detailed simulation results.A numerical study of fluid flow and heat transfer around periodic cylinder arrays under laminar cross flow conditions is presented. The investigation considers flow in sparse square and triangular arrays, with fluid fractions ranging from 0.80-0.99 and particle Reynolds numbers from about 3-160. Volume averaging of the microscopic flow field variables is used to ascertain the functional form of coefficients appearing in the macroscopic (porous media) equations. Frictional losses are shown to follow Darcy's law when the Darcian Reynolds number is of the order of one, while significant non-Darcy effects are seen at higher Reynolds numbers. The validity of the Forchheimer and Ergun correlations is shown to be suspect for flow in this highly porous media. Local thermodynamic equilibrium is relaxed in order to explore cylinder-to-fluid convective heat transfer. Power-law relationships for frictional losses and Nusselt number are shown to correlate well with detailed simulation results

Heat transfer enhancement with porous inserts in recirculating flows

This investigation explores the use of porous inserts for heat transfer enhancement in recirculating flows, specifically flow over a backward-facing step. Numerical computations are performed for laminar flow with high porosity inserts, which are composed of small-diameter (150 μm) silicon carbide fibers aligned transverse to the streamwise flow. The inserts are varied in length and porosity in order to determine the most favorable combinations of maximum temperature reduction and head loss penalty. In general, the porous inserts reduce or eliminate the lower wall recirculation zone; however, in some cases the recirculation zone is lengthened if the inserts are short and extremely porous. Excellent heat transfer characteristics are shown within the inserts themselves due to the high-conductivity fiber material. Non-Darcy effects are shown to be important primarily as the porosity is increased. Deviation from local thermodynamic conditions between the inserts and the fluid is most apparent for the shortest inserts considered

Radiation-assisted internal heat transfer enhancement with fiber arrays

Heat transfer enhancement in heat exchanger devices is not only important towards achieving improved performance, but can be crucial in extending equipment lifetime in highly corrosive environments via lower operating temperature. This paper explores radiation-assisted internal heat transfer enhancement with fiber arrays, a technique which has potential for novel heat exchanger designs where temperature reduction is a primary concern. In this technique, small diameter fibers (approx. 100 μm) are inserted longitudinally within an externally heated tube. Radiative interaction between fibers and tube wall and convective transport from fibers to the fluid drive the heat transfer augmentation. In this work, coupled radiation, conduction and convection within an externally heated tube containing uniform fiber arrays have been numerically modeled for steady state, laminar flow (ReD = 1000) via a multilevel modeling approach. At the macroscopic scale, volume-averaged porous media equations (Darcy-Brinkman-Forchheimer flow) have been utilized to model the fluid flow and heat transfer within the highly porous fiber arrays (porosity ≥ 0.9800). Simplified local modeling is used to define globally-based porosity parameters and radiative extinction coefficients, which are functions of fiber material, size, and orientation. For the given conditions, results show that the optimum heat transfer rate occurs within a narrow porosity band ranging from 0.9950 to 0.9980, whereby wall temperatures are reduced by up to 30%. The increased pressure drop due to the presence of the fibers rises monotonically as the porosity is reduced

Convective and radiative internal heat transfer augmentation with fiber arrays

A detailed numerical study is performed to investigate radiative and convective heat transfer enhancement in pipes filled with small diameter (∼100 μn) silicon carbide fibers. Radiation between fibers and the tube wall, conduction within fibers and convection from the fibers to the surrounding fluid drive the heat transfer enhancement. Macroscopic (porous media) modeling is used to determine the velocity, pressure, and temperatures fields for periodic fiber arrays of various porosites under laminar flow conditions (ReD = 1000). Key features of the macroscopic model include twodimensional effects, nongray radiative exchange, and the relaxation of the local thermodynamic equilibrium assumption. Results show that fiber arrays increase heat transfer largely by the radiative mode, with significant enhancement shown for porosities as high as 0.99. The increased pressure drop due to the presence of the fibers rises monotonically as the porosity is reduced. © 1998 Elsevier Science Ltd. All rights reserved

NBR1 is a critical step in the repression of thermogenesis of p62-deficient adipocytes through PPARγ.

Activation of non-shivering thermogenesis is considered a promising approach to lower body weight in obesity. p62 deficiency in adipocytes reduces systemic energy expenditure but its role in sustaining mitochondrial function and thermogenesis remains unresolved. NBR1 shares a remarkable structural similarity with p62 and can interact with p62 through their respective PB1 domains. However, the physiological relevance of NBR1 in metabolism, as compared to that of p62, was not clear. Here we show that whole-body and adipocyte-specific ablation of NBR1 reverts the obesity phenotype induced by p62 deficiency by restoring global energy expenditure and thermogenesis in brown adipose tissue. Impaired adrenergic-induced browning of p62-deficient adipocytes is rescued by NBR1 inactivation, unveiling a negative role of NBR1 in thermogenesis under conditions of p62 loss. We demonstrate that upon p62 inactivation, NBR1 represses the activity of PPARγ, establishing an unexplored p62/NBR1-mediated paradigm in adipocyte thermogenesis that is critical for the control of obesity

Evaluation of insulin-mimetic trace metals as insulin replacements in mammalian cell cultures

10.1007/s10616-004-6173-2Cytotechnology453107-115CYTO