Laminar viscous flow fields in moving curved channels

The laminar steady flow of air through moving narrow deep circumferential grooves on a rotor is studied. Fluid enters the moving grooves from a stationary inlet nozzle with uniform velocity and exits into a stationary diffuser after approximately 150 degrees of rotation. Three dimensional developing velocity profiles and pressure distributions are presented for a variety of operating conditions. Computed overall head-flow characteristics are found to be in relatively close agreement with a simple Poiseuille model where both walls are taken to be moving at the same rate and in the same direction at a velocity different from the entrance velocity.     

Experimental study on shear resistance of reactive powder concrete beams without stirrups

Abstract

The tests results of 18 longitudinally reinforced reactive powder concrete (RPC) beams without stirrups and subjected to combined flexural and shear are presented in this paper. The main test variables were the ratio of the shear span-to-effective depth (a/d), the ratio of the longitudinal reinforcement (ρ_w), the percentage of steel fibers volume fractions (V_f) and the percentage of silica fume (SF) powder. The findings of this paper reveal that addition of steel fibers into the RPC mixture does not considerably affect the initial diagonal cracking load but it influences the ultimate load capacity. For all tested fibrous RPC beams, the ratio of the ultimate shear force to diagonal cracking force (V_u∕V_cr) have an average ratio of about 2.5. The shear design equations recommended by the (ACI 318-14) code, (CSA A23.3-04) code, (NZS 3101-06) code and (BS 8110-97) code have been modified to predict the ultimate shear strength of RPC beams without stirrups. The suggested equations gave satisfied predictions for the shear strength of the tested RPC beams with coefficients of variation (COV) ranging from 0.09049 to 0.1817.     

Colour changes of heat‐treated woods of red‐bud maple,European hophornbeam and oak

Colour evolution and colour changes were analyzed from small specimens of three heat treated wood species using the CIE L*a*b* colour space. Upon heat exposure, the wood substance became darker of species; this was accompanied by a steady reduction in lightness. As treatment conditions (e.g., time and temperature) increase, various shades of yellow were favoured for the surface of red‐bud maple wood (Δb = 1.22–9.79). For European hophornbeam wood, increased times at elevated temperatures make a blue (?b) colour the better choice. The total colour difference (ΔE) of the surfaces of wood substrates appear to be well correlated with the treatment temperature and time. The FTIR spectra suggest that the level of modification was insufficient for removing the major cell wall constituents of the wood substrates. All heat‐treated samples showed much less stability against colour difference in outdoor conditions. For red‐bud maple, the greatest improvement was achieved for samples that were treated at 150°C for 2 h (ΔE = 3.12). However, heat‐treated oak wood hadmuch less stability of colour difference for treatment conditions of 150°C for 10 h. © 2010 Wiley Periodicals, Inc. Col Res Appl, 2010.     

Task Classification and Scheduling Based on K-Means Clustering for Edge Computing

Wireless Personal Communications - The rapid evolution of Internet of Things and cloud computing have endorsed a novel computing paradigm called edge computing. Here tasks are processed by edge...     

Influence of inulin and demineralised whey powder addition on the organic acid profiles of probiotic yoghurts

In this study, the effect of the different concentrations of inulin and demineralised whey (d‐whey) powder on the chemical characteristics and organic acid profiles of probiotic yoghurts were investigated. Analysis of chemical composition was performed on the first day, while pH and organic acid profiles were carried out during storage. The results indicated that different proportions of inulin and d‐whey powder significantly influenced the levels of the organic acids, produced while the duration of storage affected the orotic, pyruvic, citric, lactic and acetic acid levels. There was a direct relationship between the level of d‐whey powder and organic acid (except for butyric acid) concentration in the probiotic yoghurt.     

Turkey's Hydropolitics of the Euphrates-TigrisBasin

Turkey is going through a transition period and trying to realize its potential. The Southeastern Anatolia Project (GAP) is an integrated development project; it is expected to affect the entire structure of the area in its economic, social and cultural life. It is envisaged as the means of bridging the gap between the southeastern region and the more advanced areas of Turkey and of increasing the welfare of the region. The GAP Project has caused great anxiety to Syria and Iraq. In order to solve the water problem between Syria and Iraq, Turkey launched a 'Three Stage Plan'. Turkey considers the issue as an economic rather than a political one.     

Influence of metal-wustite separation on the reduction of wustite with hydrogen

The reduction rate of wustite with hydrogen at 1133 to 1233 K and for hydrogen pressures between 1.6 and 5 mbar has been measured gravimetrically upon varying the separation between tablets made of wustite and iron or nickel. The reduction rate of wustite is increased by a factor 2.4 prior to precipitation of iron on wustite when the wustite-metal distance is changed from 2 mm to 0.35 at H₂ pressures of 1.6 mbar and 2.3 mbar respectively. It has thus been demonstrated for the first time, that the catalytic effect of the metal phase on wustite reduction also exists when metal and wustite are separated. To describe this catalytic effect mathematical relations have been derived on the basis of a reaction model. These relations are in good accord with the results of the measurements. From recently published experimental findings, it may be concluded that, as a result of heterogeneous reactions, translationally ‘hot’ H₂ molecules are desorbed from the metal surface. These induce a rapid reaction at wustite unless they have been deactivated by molecular collisions within the bulk gas between the tablets.     

The effects of commercial starter culture and storage temperature on the oxidative stability and diacetyl production in butter

In this study, the effects of four different direct-vat-set (DVS) commercial starter cultures (CHN11, CHN22, EZAL BT001 and MM100) and storage temperatures (4  ±  1 and −18  ±  2°C) on the oxidative stability and diacetyl production in butter during a 4-month period were investigated. Samples were taken from butter on days 3, 30, 60, 90 and 120. Analyses of titration acidity, peroxide value, free fatty acids and diacetyl contents of the samples taken were carried out. The effects of the starter cultures on the peroxide value and diacetyl contents were found to be significant ( P  < 0.01) while the storage temperatures significantly affected all parameters tested. Interaction between the type of culture and storage temperature was significant for free fatty acids ( P  < 0.05) and diacetyl content ( P  < 0.01).     

High Diversity Transceiver for Low Power Differentially Encoded OFDM System

In this work, we investigate differentially encoded blind transceiver design in low signal‐to‐noise ratio (SNR) regimes for orthogonal frequency‐division multiplexing (OFDM) signaling. Owing to the fact that acquisition of channel state information is not viable for short coherence times or in low SNR regimes, we propose a time‐spread frequency‐encoded method under OFDM modulation. The repetition (spreading) of differentially encoded symbols allows us to achieve a target energy per bit to noise ratio and higher diversity. Based on the channel order, we optimize subcarrier assignment for spreading (along time) to achieve frequency diversity of an OFDM modulated signal. We present the performance of our proposed transceiver design and investigate the impact of Doppler frequency on the performance of the proposed differentially encoded transceiver design. To further improve reliability of the decoded data, we employ capacity‐achieving low‐density parity‐check forward error correction encoding to the information bits.