Advanced Materials Research Vols. 838-841

Abstract: Thermal insulation material with flexural strength 0.597 MPa, compressive strength 1.1111 MPa and porosity 46.71% shows that its density of the materials decreases down to 0.5466 g/cm³ using sugar filter mud as raw material. The closed porosity and dense structure of sample has been observed by photograph and the main crystalline phases of the sample using XRD techniques are tricalcium silicate and ettringite. These mineral reacting with water will occur the hydration reaction and is contribute to improve the strength of the body.

Abstract: The insufficient occurrence of raw material resources on our territory was one of the historical reasons for marginal production of sulphated binders from secondary raw-material resources. Also the unprofitability of material production based on calcium sulphate was related to this fact. This was changed in the end of the last century when formation of waste raw materials increased with industrial development. Secondary gypsums became basic raw material for production of plaster boards, plaster mixtures and anhydrite self-levelling mixtures. Wet flue gas cleaning desulphation process during which the energogypsum is formed is nowadays realised in major part of our power stations. Annual production of the energogypsum produced in this way in particular power stations is about 250 kt. The energogypsum is generally stored in stock piles as a so called stabilisate and partially is delivered to cement works as a solidification regulator. Chemogypsum is produced in chemical works where waste waters with content of SO₄^2- occur, which must be desulphated with lime in water ambient. Further it is formed in citric acid productions where also sulphated waters occur. Last but no least it is also produced in industrial production of phosphates. Production of titanium dioxide is another example of the industry where the possibility of gypsum formation exists.

Abstract: Due to the very gradual hydration of anhydrites and their very low strengths, modification of the properties of anhydrite by a suitable external exciter was resolved within the work. The experimental work was conducted on natural anhydride, and as possible exciters for hydration, the following products were selected and tested: water-free sodium sulphate; Portland cement CEM I 42,5 R; hydrated lime CL 90 Carmeuse. The dose of the exciter was consistent, i.e. 4.5 wt%. The affect on the increased speed of the hydrating process and the quality of the technological properties was monitored. The catalytic effect was evaluated by monitoring the course of the hydration process (using XRD analysis and thermo-gravimetric analysis) and also on the basis of the achieved technological properties.

Abstract: This study aims to utilize a Geographic Information System (GIS) as an arc routing tool (door-to-door model) for a recyclable materials selective collection program. The investigation uses real data from material gatherers association in the city of Itajubá, Minas Gerais, Brazil. The research method is modeling and simulation. TransCAD 4.8 is used because it possesses an arc routing routine. Scenarios were simulated in which the most efficient routes were sought (shortest and fastest) in comparison with the associations real trajectories, which were collected in the field of study by means of a Global Positioning System (GPS) device. The results obtained, when compared to the current system, showed better performance (distance, time and volume of material). Thus, by using a GIS, it can be said the main logistics problems in the gatherers association are direct consequences of poor structuring.

Abstract: An exhaustive study should be carried on impermeability of crumb rubber concrete in this paper. The orthogonal experimental design method was used in mixture proportion design and considered three factors and four levels respectively. Tests were carried out to investigate the behavior of different concretes with water to cement ratio, rubber content and sand to coarse aggregate ratio (S_p). The research shows that appropriate proportional fine aggregate replaced by rubber powder can improve impermeability of concrete. Rubber content played most important role among them and water to cement ratio took second place. S_p had a little effect on permeability of rubber concrete.

Abstract: To confirm Spatial variations of Kuroshio nutrient transport from the East China Sea to South of Japan, we apply an inverse method to hydrographic data from sections across the Kuroshio path from the East China Sea (Sections PN and TK) to south of Japan (Sections ASUKA and 137E) to get absolute geostrophic velocity, then the nutrient flux (velocity times concentration) and nutrient transport (integration of flux over a section) were calculated. In addition, Section OK east of the Ryukyu Islands was also examined. The nitrate flux during winter of 2009 shows a subsurface maximum core with a value of 11, 15, 7, 19,and 10 mol m^-2s^-1 at Sections PN, TK, OK, ASUKA and 137E, respectively. The depth of subsurface maximum core is about 280, 470, 800, 200, and 470 m at Sections PN, TK, OK, ASUKA and 137E, respectively. The eastward nitrate transport is 248.6,213.3,97.7,804.3,879.0 k mol s^-1 at Sections PN, TK, OK, ASUKA and 137E, respectively. Comparisons between nitrate transport through Section ASUKA and the sum of transports through Sections TK and OK and nitrate transport of Section 137E, suggest that the Kuroshio recirculation south of Shikoku can significantly intensify the eastward nitrate transport by the Kuroshio and therefore plays an important role in the nitrate transport in the Kuroshio region.

Abstract: An experiment was carried out to determine the effect of water deficit regulated with mulched drip irrigation on plant growth of processing tomato in an arid environment. The results indicated that Water deficit had little effect on plant height of processing tomato at full fruiting and late fruiting except that at seedling and flowering. Still, no effect of water deficit regulation on stem diameter was found at all measured growth stages. However, leaf area index and dry matter was significantly (p<0.05) reduced at all growth stages of tomato subjected to high water deficit at seedling. Therefore, low level of water deficit at seedling while free of deficit from flowering to late fruiting as well as proper levels of water deficit at flowering or full fruiting or late fruiting while free of deficit at seedling could be used to effectively regulate leaf growth and dry matter accumulation of processing tomato in arid areas.

Abstract: An experiment was conducted to determine the effect of water deficit regulated with mulched drip irrigation on photosynthetic physiology characteristics at potato tuber initiation in an arid environment. The results indicated that potato leaf photosynthetic rate (PR), transpiration rate (TR) and stomatal conductance (SC) at tuber initiation were greatly affected by water deficit regulated with mulched drip irrigation. Daily PR varied with a double-peak curve within a day at tuber initiation. The TR increased sharply after 7:00 and the maximum was marked at 13:00 in all the treatments and CK at tuber initiation, then started to decrease, and TR also decreased with soil water deficit level increase, so was SC performance. Significant positive relations (p<0.01, r=0.310**) was found between leaf water use efficiency (WUE) and PR at potato tuber initiation, but significant negative relation between WUE and TR (p<0.01, r=-0.534**) and that between WUE and SC (p<0.01, r=-0.527**) also occurred. Therefore, proper levels of water deficit regulated with mulched drip irrigation could be used to effectively regulate crop photosynthetic physiology characteristics at potato tuber initiation in an arid environment.

Abstract: the phosphorus-molybdenum-tungsten heteropoly acid catalyst is prepared from such raw materials as phosphoric acid, sodium molybdate, sodium tungstate and characterized by infrared spectrum. Glyoxylic acid is prepared by catalytic oxidation of glyoxal in the presence of the self-prepared heteropoly acid catalyst and oxidizing agent hydrogen peroxide. The impact of catalytic reaction temperature, added catalyst, and use level of the hydrogen peroxide on the reaction for synthesizing the glyoxylic acid is investigated. The results show under such conditions as 4°C temperature, 0.15g catalyst, and 1.2:1 molar ratio of the hydrogen peroxide to the glyoxal, the phosphorus-molybdenum-tungsten heteropoly acid catalyst has higher catalytic activity and the mass fraction of the glyoxylic acid is 30%.

Abstract: Photo-degradation alkali lignin was prepared in sunlight by the system of TiO₂ and squaraine dye (QSC). The antioxidant activity of photo-degradation was researched. The results showed that the phenolic hydroxyl of degradation alkali lignin is 5.63% with the control is 4.64%, and alcoholic hydroxyl of degradation alkali lignin is 3.21% with the control is 3.77%. The order of antioxidant activity was as following. 2,6-di-tert-butyl-4-methylphenol > high-phenol lignin > the control lignin.