Thermal Microwave Emission from Vegetated Fields: A Comparison between Theory And Experiment

The radiometric measurements over bare field and fields covered with grass, soybean, corn, and alfalfa were made with 1.4-and 5-GHz microwave radiometers during August-October 1978. The measured results are compared with radiative transfer theory treating the vegetated fields as a two-layer random medium. It is found that the presence of a vegetation cover generally gives a higher brightness temperature TB than that expected from a bare soil. The amount of this TB excess increases with increase in the vegetation biomass and in the frequency of the observed radiation. The results of radiative transfer calculations, which include a parameter characterizing ground surface roughness, generally match well with the experimental data.     

Results of studying atmospheric corrosion in Vietnam 1995–2005

Vietnam is situated in the wet tropical zone; thus, atmospheric conditions are characterized by high temperatures and a long time of wetness (TOW). In addition, the salt air coming in from the sea causes a high chloride concentration in coastal areas. Furthermore, Vietnam is a developing country, which means that air pollution is increasing with the development of industry. These factors result in significant damage to materials by atmospheric corrosion. In this report, the results of a recent study on the corrosion of carbon steel and zinc-galvanized steel at 6–8 testing sites in Vietnam over 10 recent years (1995–2005) are focused on as well as the effects of environmental factors on atmospheric corrosion. The results showed that the corrosion of carbon steel is dominated by TOW, whereas zinc-galvanized-steel corrosion strongly depends on the chloride ion concentration in the air. The corrosion losses of both carbon- and zinc-galvanized steel fit the power model well with high correlation coefficients. In addition, the characteristics of the Vietnamese climate are introduced in the form of distribution maps of temperature (T), relative humidity (RH), total rainfall and TOW. A relationship between TOW, T and RH was found that enabled the calculation of TOW from T and RH data, which are available at meteorological stations. Finally, atmospheric corrosivity is determined on the basis of data on TOW, Cl⁻ and SO₂ concentrations, and the carbon steel corrosion rate. It is shown that in Vietnam, TOW is so long that the corrosion rate of carbon steel is in the C₃ category; nevertheless, Cl⁻ and SO₂ concentrations in the atmosphere are not high.     

四川盆地蓬莱—中江地区震旦系灯影组二段成藏特征

通过钻井、岩心、测录井及地震资料的综合分析,系统研究了四川盆地蓬莱—中江地区震旦系灯影组二段气藏的成藏特征。研究结果表明：①四川盆地灯影组沉积期,随着海水侵入,古陆多被淹没或侵蚀夷平,盆地逐渐演变为碳酸盐岩台地。灯二上亚段沉积期,川中北斜坡蓬莱—中江地区以发育台地边缘滩相和台地边缘丘相为特色,并可细分为滩核、滩缘、滩间海、丘核、丘缘、丘间海6种亚相,是储层发育的有利相带。②研究区灯二上亚段储层以藻云岩、藻砂屑云岩为主要储集岩,发育残余粒间孔+粒间溶孔型、粒内溶孔+藻格架孔型、裂缝型与孔洞型4种类型的储层,储层厚度分布特征与沉积相分布特征较吻合,位于台地边缘丘滩核的储层累积厚度大。③研究区灯二上亚段气藏的天然气主要来源于筇竹寺组烃源岩,烃源岩厚度大、有机碳含量及热演化程度高,气藏具备较好的烃源条件和封盖条件,具有“上生下储上盖”和“旁生侧储上盖”2种较好的生-储-盖配置关系。④研究区油气充注主要发生于三叠纪—白垩纪,为多期“准连续”型,灯二上亚段气藏主要经历了奥陶纪—志留纪古油气藏聚集阶段、志留纪—石炭纪古油藏破坏阶段、二叠纪—三叠纪再次生烃成油藏阶段和三叠纪—侏罗纪原油裂解生气阶段。     

The process to make a ridge- and fringe-field multidomain structure using a photoimageable polymer for a wide viewing angle liquid crystal display application

Liquid crystal display (LCD) is very important in the computer industry and many other areas. However, the application of LCD is limited by its narrow viewing angle, compared with a cathode ray tube (CRT) display. In this article a new type of LCD [ridge- and fringe field multidomain homeotropic (RFFMH) LCD], is introduced. In RFFMH LCD, a transparent photoimageable polymer resist is applied to build ridges on each pixel to control the liquid crystal pretilt direction. This photolithographic step imparts a wider viewing angle and simpler LCD production process. In this article the detailed process of building the ridge structure is described, and the thermal stability and chemical resistance of this polymer are studied. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 1197–1203, 1999     

Evaluation of pre-coated recycled concrete aggregate for hot mix asphalt

Recycled concrete aggregate (RCA) used for pavement construction can ease aggregate shortage problem and reduce environmental pollution. The mechanical properties of hot mix asphalt (HMA) with RCA are usually inferior to those of HMA with river crushed stone (CS). In this research, slag cement paste used for pre-coated RCA (PCRCA) with coating thickness of 0.25 mm, 0.45 mm and 0.65 mm to reinforce its ability is evaluated. The result shows that the PCRCA with coating thickness of 0.25 mm has the optimum coating paste volume for HMA mixture. The indirect tensile strength (ITS) test, moisture sensitivity test and wheel-track rutting test of HMA with substitution ratios of 25%, 50%, 75% and 100% PCRCA mixture are discussed. The results indicate that the properties of PCRCA have highly pores contents, absorption of water and asphalt contents. However, the physical properties of the PCRCA used as aggregate and test of HMA with PCRCA are within the range of the specification requirements.     

Reductive activation of dioxygen for degradation of methyl tert-butyl ether by bifunctional aluminum

Bifunctional aluminum is prepared by sulfating aluminum metal with sulfuric acid. The use of bifunctional aluminum to degrade methyl tert-butyl ether (MTBE) in the presence of dioxygen has been examined using batch systems. Primary degradation products were tert-butyl alcohol, tert-butyl formate, acetone, and methyl acetate. The initial rate of MTBE degradation exhibited pseudo-first-order behavior, and the half-life of reaction was less than 6 h. XPS analysis indicates the formation of sulfate at the surface of bifunctional aluminum. The concentration of surface sulfate varies linearly with increasing strength of the sulfuric acid used during bifunctional aluminum preparation. The rate of MTBE degradation is a function of the concentration of the surface sulfate. MTBE degradation rates increased by a factor of 2 as surface sulfate concentrations increased from 233 to 641 micromol/m2. This relationship implies that sulfate at the surface of bifunctional aluminum acts as a reactive site.     

Changes in β-carotene bioaccessibility and concentration during processing of carrot puree

The effect of some process and product factors (addition of olive oil, high pressure homogenisation, subsequent thermal or high pressure pasteurisation) on β-carotene bioaccessibility and isomerisation of carrot puree was investigated. High pressure homogenisation could improve β-carotene bioaccessibility by disrupting cells, but only at a pressure higher than 50 MPa. Softening of the cell walls during a subsequent thermal pasteurisation resulted in a further increase in β-carotene bioaccessibility. Unfortunately, the high temperature also induced formation of some undesirable cis-isomers. As cell walls are probably strengthened by high pressure, high pressure pasteurisation could not positively affect the amount of bioaccessible β-carotene. Moreover, the high pressure process induced β-carotene oxidation. A positive effect of olive oil on β-carotene bioaccessibility could only be noticed in combination with a thermal pasteurisation process when β-carotene was solubilised in the oil droplets. Under high pressure however, oil can be crystallised which hinders the solubilisation of β-carotene.     

The type and quantity of lipids present during digestion influence the in vitro bioaccessibility of lycopene from raw tomato pulp

This study elucidates the impact of the type and quantity of lipids, added upon digestion of raw tomato pulp, on the bioaccessibility of lycopene. Lycopene bioaccessibility was studied by measuring the micellarization during in vitro digestion. Coconut oil, palm oil, cocoa butter, olive oil, sunflower oil and fish oil were selected because of their distinctly different fatty acid composition. Upon adding 5% of lipid to raw tomato pulp, all tested lipids significantly improved the lycopene bioaccessibility. The largest increase in lycopene bioaccessibility was noticed after supplying 5% of sunflower oil, followed by olive oil and cocoa butter (not all differences were significant). A slightly smaller increase was observed when fish oil, coconut oil and palm oil were used. In addition, the effect of different quantities (0–10%) of coconut oil, olive oil and fish oil was examined. Over the entire concentration range, increasing the amount of coconut oil increased the lycopene bioaccessibility, while the highest bioaccessibility was found using 1 and 2% of respectively fish oil and olive oil. Moreover, depending on the amount of added lipid, the type of lipid resulting in the highest lycopene bioaccessibility differed. The results obtained clearly indicate that lycopene bioaccessibility depends both on the type and on the quantity of the lipid present during in vitro digestion of raw tomato pulp.     

Evaluation of the antioxidant activity of five endemic Ligustrum species leaves from Taiwan flora in vitro

Leaves from the plant species belonging to the genus Ligustrum are widely used as tea or herbal medicine in Europe, China, and Japan. The antioxidant properties of five Ligustrum species from Taiwan were compared using in vitro antioxidant methods such as DPPH radical scavenging, TEAC, and FRAP assays. Cell-based antioxidant methods were used, including Fe²⁺/ascorbate-induced lipid peroxidation on brain homogenate and AAPH-induced erythrocyte haemolysis. The amounts of major phenolic compounds from the Ligustrum species, including phenylpropanoids, flavonoids, and iridoids, were determined by spectrophotometric methods. The results showed that all Ligustrum species exhibited antioxidant, radical-scavenging, anti-haemolytic, and lipid peroxidation-inhibiting activities at different magnitudes of potency. A significant correlation was found between antioxidant activity and the amount of antioxidant components, in particular, total phenolics and phenylpropanoids. Among all Ligustrum species from Taiwan, Ligustrum morrisonense is presented as potential source of natural antioxidants.