Modelling of heat transfer in an infiltrated granular bed in view of the difference of phase temperatures

Physically substantiated boundary conditions for problems of heat transfer in infiltrated granular beds based on the two-temperature model which allow for the absence of interphase heat transfer on boundaries are formulated. It is shown that classical Dankwerts conditions would be applicable for gas. The problem of porous cooling at the boundary conditions of the 2nd and 3rd kind on the outer boundary is solved in a new formulation.     

Ennoblement of stainless steel in natural seawater – A new explanation

The ennoblement of corrosion potential (E_corr) of passive metal immersed in seawater was investigated with electrochemical technology and epifluorescence microscopy. The in situ observation showed that the bacteria number increased on the metal surface according to an exponential law which was in the same way with the ennoblement of E_corr. At the same time, the anodic polarization current of high‐Mo stainless steel decreased in the initial days. According to the mix‐potential theory and the characteristics of polarization curves of high‐Mo steel in natural seawater, the ennoblement of corrosion potential may be induced by the decrease of the passive current density.     

Level set and geodesic active contours based measurement of material removal between serial sections

The measurement of the thickness of material removed between serial sections is a crucial step of three-dimension reconstruction. Geodesic active contours is an efficient method for contour detection of objects on an image. The indents on the SiC/Al composite micrographs are segmented by using level set and geodesic active contours. After getting the contours of the indents, we calculate the distance from the uppermost pixel to the lowermost pixel to get the vertical diagonal length, and calculate the distance from the leftmost pixel to the rightmost pixel to get the horizontal diagonal length of each contour. Then the final length of each diagonal is acquired by averaging the vertical diagonal length and the horizontal diagonal length, respectively. The Vickers’ indenter is made by a square pyramidal-shaped diamond with opposite faces at an angle of 136°, so the thickness of material removed between two serial sections and the length difference of the diagonals on the two serial sections has a definite geometrical relation. Thus the thickness of material removed between two serial sections is acquired using the geometrical relation.     

Electrochemical characteristics of heme proteins in hydroxyethylcellulose film

A stable film made from hydroxyethylcellulose (HEC) on pyrolytic graphite (PG) electrode was employed for incorporating hemoglobin (Hb), myoglobin (Mb) and horseradish peroxidase (HRP), and the electrochemical characteristics of the proteins were studied correspondingly. Experimental results revealed that HEC film could greatly accelerate electron transfer between the proteins and electrode, and the proteins showed a thin layer electrochemical behavior in the film. Moreover, all the proteins in the film exhibited good catalytic activity towards the reduction of hydrogen peroxide (H₂O₂) in the low H₂O₂ concentration range. In the high concentration range, H₂O₂ would exhibit toxicity effect on the proteins. The electrochemical properties and electrocatalytic abilities of the three heme proteins in HEC film have been compared, and the optimal conditions for H₂O₂ biosensor fabrication have been obtained.     

Performance of a combined eco-system of ponds and constructed wetlands for wastewater reclamation and reuse.

An on-site study on the operational performance of a combined eco-system of ponds and SF constructed wetland for municipal wastewater treatment and reclamation/reuse in Donging City, Shandong, China was carried out from January 2001 through October 2003. The removal efficiencies for various main parameters were: TSS 84.8 +/- 7.3%, BOD5 87.2 +/- 5.3%, CODCr 70.2 +/- 18.6%, TP 52.3 +/- 23.1%, and NH(3)-N 54.8 +/- 23.9% with effluent concentration of TSS 9.12 +/- 5.12 mg/l, BOD5 6.44 +/- 4.58 mg/l, CODCr, 42.8 +/- 6.7 mg/l, TP 0.94 +/- 0.27 mg/l and NH(3)-N 7.95 +/- 2.36 mg/l. In addition, the removal efficiencies for faecal coliforms and total bacteria were > 99.97% and > 99.998% respectively, which well meet Chinese National standards for effluent quality of municipal wastewater treatment plants. The composition of TSS was closely related to CODCr and BOD5 variations, and nitrification-denitrification is the major mechanism of nitrogen removal both in ponds and in wetlands. In addition, sedimentation also played an important role in the removal of TSS, nitrogen, phosphorus and BOD5. The removal efficiencies of various parameters, the number of species and biomass of biological community in the system increased gradually with the ecological maturation.     

Influence of aggregate content on the migration coefficient of concrete materials using electrochemical method

In order to investigate the effect of coarse aggregate content on the chloride ion migration coefficient of concrete, specimens with different coarse aggregate volume fractions and two water/cement (w/c) ratios of mortar matrix were used. The chloride ion migration coefficient of concrete is obtained using the electrochemical technique to accelerate chloride ion migration in cement-based material and the experimental results were plotted as a function of the fine aggregate volume fraction. The results are analyzed comparing experimental results and theoretical models that represent the concretes as three-phase composite materials. The three phases are the mortar matrix, the coarse aggregate, and the interfacial transition zone between the two. The chloride ion migration coefficient is used to assess the dilution, tortuosity, interfacial transition zone (ITZ) and, percolation effects of coarse aggregate in concrete. It appears that the dilution and tortuosity effects are a dominant factor affecting the chloride ion migration coefficient of concrete in the low volume fraction of coarse aggregate. As the volume fraction of coarse aggregate increases to 40 and 20% in concrete of w/c ratio 0.35 and 0.45, respectively, the ITZ with percolation effects are significantly.     

Optimal determination of warranty region for 2D policy: A customers' perspective

Warranty is treated by the manufacturer as a marketing strategy that creates better customer satisfaction, which finally helps to get hold of a bigger market share. The cost incurred towards this service is termed as warranty cost, which is a function of warranty policy and region, product quality and reliability, and the customers' usage pattern. Under the 2D warranty policy, there exists numerous iso-cost regions for any specified value of warranty cost. In this article, we propose a methodology to determine the optimal region when customers' utility is measured by the length of warranty coverage time. It is believed that the results will help the manufacturer to provide improved customer service.     

MECHANISM OF SOUND GENERATION BY FLOW OVER TWO CAVITIES IN TWO DIMENSIONS

1 .　ＩＮＴＲＯＤＵＣＴＩＯＮＷｈｅｎｈｉｇｈ ｓｐｅｅｄａｉｒｆｌｏｗｏｒｃｕｒｒｅｎｔｐａｓｓｅｓｏｖｅｒｇａｐｓｏｒｃａｖｉｔｉｅｓｉｎａｆｌａｔｐｌａｔｅ ,ｓｅｌｆ ｅｘｃｉｔｅｄｏｓｃｉｌｌａｔｉｏｎｓｍａｙｏｃｃｕｒ ,ｌｅａｄｉｎｇｔｏｄｒａｍａｔｉｃｐｒｅｓｓｕｒｅａｎｄｖｅｌｏｃｉｔｙｆｌｕｃｔｕａｔｉｏｎａｎｄｉｎｔｅｎｓｉｖｅｎｏｉｓｅ .Ｔｈｅｓｅｐｈｅｎｏｍｅｎａｍａｙａｐｐｅａｒｉｎｍａｎｙｅｎｇｉｎｅｅｒｉｎｇａｐｐｌｉｃａｔｉｏｎｓ .Ｆｏｒｅｘａｍｐｌｅ ,ｗｅａｐｏｎｂ…     

THE SIMULATION OF THE SAR IMAGE OF INTERNAL SOLITARY WAVES IN ALBORAN SEA

1 .　ＩＮＴＲＯＤＵＣＴＩＯＮＯｃｅａｎｉｎｔｅｒｎａｌｗａｖｅｉｓａｋｉｎｄｏｆｇｒａｖｉｔｙｗａｖｅｇｅｎｅｒａｔｅｄｉｎｔｈｅｓｔｒａｔｉｆｉｅｄｏｃｅａｎ .Ｉｔｐｒｏｄｕｃｅｂｙｔｈｅｉｎｔｅｒａｃｔｉｏｎｏｆｔｉｄｅｃｕｒｒｅｎｔａｎｄｔｏｐｏｇｒａｐｈｙ ,ｓｅａｑｕａｋｅａｎｄｍｏｖｉｎｇｓｈｉｐｗｈｅｎｔｈｅｓｔｒｏｎｇ ,ｓｈａｌｌｏｗｐｙｃｎｏｃｌｉｎｅｉｓ ｐｒｅｓｅｎｔ.Ｔｈｅｉｎｔｅｒｎａｌｗａｖｅｓｉｎｔｈｅｃｏｎｔｉｎｅｎｔａｌｓｈｅｌｆａｒｅａｌｍｏｓｔｔｉｄｅｐｒｏｄ…     

GENERATION OF NONLINEAR INTERNAL WAVES ON CONTINENTAL SHELF

1 .　ＩＮＴＲＯＤＵＣＴＩＯＮＩｎｔｅｒｎａｌｔｉｄａｌｉｎｔｅｒａｃｔｉｏｎｗｉｔｈｂｏｔｔｏｍｆｅａｔｕｒｅｓａｐｐｅａｒｓｔｏｂｅｔｈｅｄｏｍｉｎａｎｔｍｅｃｈａｎｉｓｍｆｏｒｇｅｎｅｒａ ｔｉｏｎｏｆｔｈｅｃｏｈｅｒｅｎｔｏｃｅａｎｉｃｉｎｔｅｒｎａｌｗａｖｅｓｔｈａｔａｒｅｏｂｓｅｒｖａｂｌｅｗｉｔｈＳＡＲ ,ｃｌｏｓｅｒｔｏｓｈｏｒｅ ,ｒｉｖｅｒｉｎｅｏｒｇｌａｃｉａｌｉｎｔｒｕｓｉｏｎａｎｄｃｏｎｔｉｎｅｎｔａｌｂｒｅａｋｐｒｏｖｉｄｅｓｅｃ ｏｎｄａｒｙｇｅｎｅｒａｔｉｎｇｍｅｃｈａ…