•The average heat-transfer coefficient is much higher when the plate is horizontal.•The average heat-transfer coefficient decreases with increasing orientation angle.•The average heat-transfer ...coefficient increases with increasing oscillation frequencies.
Vibration effects on thermal performances of the rectangular flat plate under natural convection condition are experimentally investigated in both horizontal and slightly inclined from horizontal orientations in multiple angles. The effects of Rayleigh number and vibrational Reynolds number on the average heat-transfer coefficient are also examined. The Aluminium made plate was subjected to sinusoidal vibration in the vertical plane. The test sample was heated under a constant heat flux. The amplitude of vibration was varied from 1.5 to 7.5 mm and the frequency of vibration from 0 to 16 Hz. From the results of the experiments, it is observed that the average heat-transfer coefficient increases linearly with increasing Rayleigh number for different orientation angles. It was also found that the average heat-transfer coefficient is much higher for the cases when the plate is horizontal, and it decreases when the orientation angle value was increased. Such as the average heat-transfer coefficient decreased by approximately 13% for 30° orientation case. The measured result further showed that the average heat-transfer coefficient in the vertical position is lower than the average heat-transfer coefficient in the horizontal position and slightly higher than the other orientation angles (i.e. 30°, 45° and 60°). Finally, it was found that the increases in oscillation frequencies lead to an increase in the average heat-transfer coefficient and the maximum increase was obtained in the horizontal position and higher frequencies. However, the average heat-transfer coefficient decreases with increasing the vibration frequencies when the plate was in the vertical position.
Computer simulations were carried out to study airflow patterns and pollution levels due to emissions from vehicles for the westbound Melbourne City Link tunnel under severely congested traffic jam ...conditions. The time averaged equations for velocity, pressure, temperature and mass fraction of emissions were solved using CFD software FLUENT 6.0. The maximum mass fractions of O
2, CO
2 and CO were found to be 0.16, 0.14 and 0.002, respectively. These high levels of pollutants were detected despite the fact that roof-mounted fans pushed exhaust fumes out the exit and sucked fresh air in from the inlet of the tunnel. During another condition of power failure, when the fans were not in operation, the flow inside the tunnel was mainly driven by buoyancy and the concentration levels of O
2, CO
2 and CO were then found to be 0.05, 0.18 and 0.0028, respectively. Theses emissions from the vehicles for both cases posed a threat to human health. To avoid this dangerous situation a multi-pronged approach is needed that includes having alternative sources of power for the fans, ensuring faster evacuation of passengers and drivers, as well as switching-off engines during prolonged traffic standstill.
A challenge facing metabolomics in the analysis of large human cohorts is the cross-laboratory comparability of quantitative metabolomics measurements. In this study, 14 laboratories analyzed various ...blood specimens using a common experimental protocol provided with the Biocrates AbsoluteIDQ p400HR kit, to quantify up to 408 metabolites. The specimens included human plasma and serum from male and female donors, mouse and rat plasma, as well as NIST SRM 1950 reference plasma. The metabolite classes covered range from polar (e.g., amino acids and biogenic amines) to nonpolar (e.g., diacyl- and triacyl-glycerols), and they span 11 common metabolite classes. The manuscript describes a strict system suitability testing (SST) criteria used to evaluate each laboratory’s readiness to perform the assay, and provides the SST Skyline documents for public dissemination. The study found approximately 250 metabolites were routinely quantified in the sample types tested, using Orbitrap instruments. Interlaboratory variance for the NIST SRM-1950 has a median of 10% for amino acids, 24% for biogenic amines, 38% for acylcarnitines, 25% for glycerolipids, 23% for glycerophospholipids, 16% for cholesteryl esters, 15% for sphingolipids, and 9% for hexoses. Comparing to consensus values for NIST SRM-1950, nearly 80% of comparable analytes demonstrated bias of <50% from the reference value. The findings of this study result in recommendations of best practices for system suitability, quality control, and calibration. We demonstrate that with appropriate controls, high-resolution metabolomics can provide accurate results with good precision across laboratories, and the p400HR therefore is a reliable approach for generating consistent and comparable metabolomics data.
Vital wheat gluten was extracted from broken wheat flour (Triticum aestivum), which is an accidental product during the technical milling process and used to improve the sensory and qualitative ...properties of bread made using flour from two varieties of Iraqi barley (IPA 99, IPA 265) which were obtained from the Ministry of Agriculture / Agricultural Research Center. The chemical composition analysis revealed that the percentage of β-glucan in barley flour (72% extraction) (BFE) of IPA 99 and IPA 265 were (3.9, 4.5%), respectively, while for whole barley flour (100% extraction) (WBF) those values were (3, 3.9%), respectively. The percentage of pentosanes in (WBF) of the experimental of varieties were (7.8, 12.6%). However, in the (BFE) these values drooped to (6.0 - 8.7%). This study, two experiments with seven treatments were carried out. The first experiment include using broken wheat wet gluten (BWWG) at different percentage in bread mix as follows, barley flour (type A) with 14% (BWWG) (T1), 16%( BWWG) (T2), 18 %( BWWG) (T3), 20% (BWWG) (T4), and 22 %( BWWG) (T5) of the experimental gluten, T6 was barley flour and 20% commercial gluten (CG) (for comprised) while T7 was barley flour with no added gluten. The second experiment was with barley flour from type (B) with a similar ratio of add gluten. The results have shown that the specific volume of the bread for IPA 99 & IPA 265 was significantly higher (P<0.05) than that of control. The highest value of specific volume were in the treatments AT5 &BT5 (3.3 & 3.34 cm3/gm) compared with the control where it was (1.43 & 1.5 cm3/gm). Sensory evaluation test showed an improvement in the sensory and qualitative characteristics of gluten contenting bread. Chemical analysis of the loaf prepared from superior treatments showed that percentage of protein increased from 10.7-113% to 25-26.6%, fiber to 1.3 - 1.8%, and carbohydrates to 57.5- 60.4% as compared with control treatment which was 74.5%.
A computational fluid dynamic (CFD) model has been developed for the simulation of slag foaming on bath smelting slag (CaO–SiO2–Al2O3–FeO) by considering foam as a separate phase. The CFD model has ...been used to predict the foam height, bubble number density and the multiphase flow phenomena in the system. The height of foam is dynamically balanced by the formation of foam due to transformation of both gas and liquid into foam and its destruction due to liquid drainage and bursting of bubbles, transforming foam back to liquid and gas. The bubble break-up and coalescence were considered in gas–liquid dispersion whereas in the foam layer, the bubble coalescence due to film rupture was incorporated. A population balance modeling was used to track the number density of different bubble classes and fixed pivot method was used to discretize the population balance equation. The model predicted the foam height of the slag system (CaO–SiO2–Al2O3–FeO). The content of FeO was changed and its effect on the foam height predicted. The foaming index was calculated and the results from the model predict that the foaming index decreases with increase of FeO content in slag. The CFD model also predicts that the foaming index of a slag with Al2O3 is higher than that of slag without Al2O3. Dimensionless analysis was performed based on the model available in the literature to correlate the foaming index with the physical properties of the slag. The predicted results from the present study are in reasonable agreement with available experimental data.
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•A CFD model was developed for the simulation of slag foaming on bath smelting slag.•The predicted foaming index decreases with increase of FeO content in slag.•The Sauter mean diameter increases with increases of FeO content in slag.•The coefficient of foaming index is in good agreement with the experimental data.•The predicted results are in reasonably good agreement with the experimental data.
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•Numerical simulations were conducted to establish the effect of particles on foam drainage.•Permeability and flow velocity was seen to decrease with higher particle volume fraction ...in foam.•Velocity profiles and particle agglomeration and distribution in PBs and nodes were simulated.•Microscopic forces between the semi-stagnant particles become dominant causing agglomeration.•The presence of solid particles in foam elevates interfacial rigidity and influences mobility loss.
We present three-dimensional models and associated numerical simulations using the Navier-Stokes and continuity equations, and we illustrate the dynamics related to flow within different foam geometries where silica particles are present in the foam. The effects of partially hydrophobic particles and hydrophilic nanoparticles on foams were studied. A microscale design was used to create models for a Plateau border and node system and for a two-nodes and Plateau border system, both within the “dry” limit, with various liquid and particle volume fractions. The influence of hydrophobic silica particles on foam drainage and permeabilities was examined through numerical simulations. The velocity profiles, particle agglomerations and particle distributions in the Plateau borders and nodes were simulated. The results obtained show that at the Plateau border scale, slow drainage occurs in the presence of deposited solid particles, and there is resultant insoluble agglomeration. The results were investigated and compared with those found in the literature, and a qualitative similarity was noted. It was observed through analysis that the presence of solid particles in foam elevates interfacial rigidity, resulting in a Plateau border-dominated regime, and thus influencing the mobility losses in the foam network. Finally, microscopic interfacial forces between semi-stagnant settled hydrophilic nanoparticles become dominant, causing agglomeration.
In the presence of harsh economic conditions, conducting laboratory experiments in a wide anticipated area to determine soil properties for any purpose or task within a city is unachievable. Hence, ...this work is focused on incorporating the existing record data of 56 distinct soil samples acquired from different pits of Kirkuk city utilizing spatial analysis described by inverse distance weighted (IDW) and Kriging methodologies. The incorporated constituents were principally categorized into basic soil characteristics such as clay, silt, sand, and gravel contents and various soil parameters such as initial void ratio (
), angle of internal friction (
), cohesion (
), and optimum soil moisture content. Moreover, quantitative approaches such as geotechnical parameters association, linear single, and linear multi-regression models were used. Significant discrepancies in both approaches are readily obvious in the third to fifth zones, indicating that IDW and Kriging processes describe the distribution of sand in Kirkuk city differently. Furthermore, linear multi-regression model between basic and investigated soil parameters show good to excellent and very good to excellent degrees of correlation, with multiple
values in the range of (0.77–0.97) and (0.86–0.98), respectively.
Vital wheat gluten was extracted from broken wheat (Triticum aestivum) and durum wheat (Triticum durum) flour and used to improve the rheological and staling characteristics of bread made using flour ...from two varieties of barley (IPA 99, IPA 265) which were obtained from the Ministry of Agriculture / Agricultural Research Center. The recent study included seven treatments being, Wheat flour was used as control treatment in bread making (T1), and barley class IPA99 flour (T2) , IPA 265 flour (T3), IPA99 flour with durum wheat gluten (T4), , class IPA 265, flour with durum wheat gluten (T5), IPA99 flour with broken wheat gluten(T6), IPA 265 flour with broken wheat gluten(T7). The bread samples were prepared according to straight dough AACC method No. 10-10 B and the final products were stored for 72 h. (20°C). The obtained results indicated that gradual increase in the bread crust moisture content coincided with a gradual decrease in the moisture content of the bread crumb during the storage period for all treatments. It has been noticed a significant difference (p<0.05) among the crumb swelling power values for all treatments, meanwhile all treatments were showed gradual decrease in the swelling power as storage time proceeded ,no significant differences (p<0.05) in the crumb swelling power between T4 and T5 as compared to the control treatment, for all storage periods. A gradual decrease in the barley bread crumb aqueous suspension sediments amount were observed as the storage period proceeded, both T4 and T5 treatments showed significant differences (p<0.05) in sediments amount as compared to the control treatment at all storage periods, this means that T4 and T5 were more resistant to the staling phenomena as compared to other treatments .Therefore, the durum wheat gluten was more effective in improving barley bread resistance to staling phenomena as compared to the broken wheat gluten._._
The quality of coal from a natural source can vary significantly as it is processed from the ground. Elevated sand loadings within the raw coal can significantly influence wear due to erosion within ...the mill-duct system of a lignite fuelled power station. A previous study 1 by the current authors investigated the gas and particle mass flow within the mill-duct system of a real-life operating power station both numerically and experimentally. This work extends the previous study by considering the wear of the mill-duct system caused by coal and varying levels of sand under normal operating conditions. At elevated levels of sand loading, the wear significantly increased in comparison with the coal only flow. Considering varying levels of sand loadings, the erosion wear at the highest sand loading case (30% by mass) produced slightly less than three times the total wear of the 10% sand loading case. This non-linear relationship can be attributed to the re-acceleration of the heavier sand particles after particle–wall collisions. The erosion patterns found within the swirl vane regions of the mill-duct confirm the findings of other researchers in the field of particulate roping. The findings suggested that the particle ropes twist around the circumference of duct when a series of bends is encountered. These findings were evident in the erosion distribution comparing the swirl vanes in the upper and lower legs of the mill-duct system. These differing erosion distributions were attributed to the rotational motion of the secondary gas flows and the difference in bend-to-swirl vane distance of the two legs. The predicted erosion wear on the upper leg swirl vanes was greater than those of the lower leg even though the particle mass flow was biased toward the lower leg. The upper and lower leg swirl vane geometry imparts an anti-clockwise rotation to the flow while the secondary flow created by the trifurcation geometry was anti-clockwise within the lower leg and clockwise within the upper leg. Thus the anti-clockwise motion created within the lower leg geometry actually aided the swirl vane motion, minimising the wear. The upper leg swirl vanes reversed the secondary flow resulting in a greater number of particle/swirl vane collisions, leading to a higher degree of wear.
This study investigates numerically, the erosion and wear on the supply duct geometry system. Differing erosion distributions found in the a mill-duct system downstream of the grinding mill at a power station in Australia, were attributed to the rotational motion of the secondary gas flows and the difference in bend-to-swirl vane distance of the two legs.
Relative erosion due to coal (left) and sand (right) in the lower main burner duct at 30% sand loading. Display omitted
► Erosion and wear were predicted and measured for a power station supply duct. ► Differing erosion distributions were attributed to flow pattern created by geometry. ► The erosion was not proportional to the particulate loadings in mill ducts.
The mechanical and thermal expression (MTE) process can be used to remove the moisture from high moisture coal such as lignite by applying the thermal energy and mechanical force. The moisture ...content of lignite at Yallourn, VIC, Australia is around 60–70%. Two-third of the water from the lignite can be removed at 150°C and 5.1 MPa by this process. In the conventional drying process, moisture is driven off by evaporation when the lignite passes through the mill. This process is inefficient from a thermodynamic point of view, because the latent heat of evaporation has to be supplied from the hot flue gas. This paper presents computational fluid dynamics (CFD) investigation of fluid flow and combustion of conventional lignite and MTE lignite in a tangentially fired full-scale industrial furnace. The idea is to investigate the aerodynamics and combustion effect of using MTE lignite in existing furnaces. The furnace investigated was Yallourn stage-2 in Victoria, Australia. CFD software CFX-4 (User Guide, CFX-4–Solver. AEA Technology. Harwell Laboratory, Oxfordshire, 1997) was used in this investigation. The MTE process is under development and has not been used in the real power station for the commercial production of electricity, hence no experimental data is available for comparison with the numerical predictions. To gain confidence in the MTE lignite simulations, the temperature contours and oxygen concentration at different furnace level of the conventional lignite combustion were validated first against the available experimental data. Then the predicted results of MTE lignite combustion were compared with conventional lignite combustion to assess the possibility of burning MTE lignite in existing tangentially fired furnaces.
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