Physicochemical Properties Of Medium Research Articles

Relationship of microstructural criteria of fracture and evolution of metal surface and physicochemical properties of medium at friction

In this work, microstructural criteria of fracture of surface layers of metal (nickel) at friction loading of surfaces in lubricating media are studied. Physicochemical criteria of oxidation of surface and film formation are determined. The effect of film on the strength properties of surface layers of metals is determined. Mechanisms of interaction of films with the dislocations of the surface layer are considered. Aspects of internal oxidation and hydrogen attack due to oxygen and hydrogen transfer along the channels of surface dislocations during mechanical and thermal fracture of the lubricant are considered.

Growth, yield and quality of spring tomato and physicochemical properties of medium in a tomato/garlic intercropping system under plastic tunnel organic medium cultivation

Continuous cropping poses a number of issues to tomato cultivation under plastic tunnels in China, and the intercropping of garlic with tomato may help to solve these problems. In this study, we compared tomato/garlic intercropping with tomato monoculture and investigated the differences in the physicochemical properties of the medium, as well as the growth, yield and quality of spring tomato, under plastic tunnel organic medium cultivation during the year 2011–2012. The results showed that the pH value was higher and the EC value was lower in the intercropping medium than in the monoculture medium. The alkaline hydrolysis content of the intercropping medium did not change significantly over the tomato growth period, but available phosphorus and available potassium were both reduced continuously. The alkaline phosphatase and cellulase activities were both higher in the intercropping medium, while urease activity was lower. The invertase activity in the intercropping medium was significantly lower than in the monoculture medium before tomato transplanting but showed a nonsignificant difference at the fruit set stage of the tomato. The total microorganism population decreased for a short period after the garlic harvest in the intercropping medium but recovered to the level of the monoculture (control) at fruit set stage of the tomato. Intercropping increased the bacterial and actinomycetous populations but decreased fungal population in comparison to monoculture. The intercropped garlic inhibited the growth of the spring tomato, but this inhibition decreased after the garlic harvest. The chlorophyll contents in the leaves were increased, but the photosynthetic rate was decreased, for the intercropping spring tomato compared to the monoculture tomato. The tomato fruit quality, in terms of the titratable acid, vitamin C and dry matter contents, was significantly higher in the intercropping system, while the solid matter, soluble protein and soluble sugar contents did not differ significantly between the two methods. Intercropping reduced the total spring tomato yield but produced a higher net income than did monoculture. In conclusion, intercropping garlic with tomato can improve both the microorganism populations and the enzyme activity of the medium, which together reduce the obstacles of continuous tomato production.

채소재배용 발포 폴리프로필렌 소재화분에 적합한 인공배지의 선발

This experiment was conducted to select light and good water-holding medium suitable for expanded polypropylene(EPP) pot judging from the growth reaction of vegetables on artificial medium. Solidity ratios were 27.4% in medium A of control and about 10% in medium B~E respectively. Vapor ratio was 90% in medium B~E, which was statistically higher than that of 72.6% in medium A. Water-holding capacities were 63.6g in medium A and more than 70g in medium B~E. pH in medium B was highest by 5.6 and pHs of medium C, D, E were higher in order. EC of medium A was the highest by 2.16 ds/m but those of medium B~E were very low by 0.43 ds/m under. Physical properties of medium used were not changed. Leaf number of endive were most by 19.2 in medium D, E. Leaf length and width of lettuce were about 19cm and 11cm in medium B~E showing no difference in medium, which were larger than 14.7cm and 9.1cm in medium A respectively. Number of leaves and root length in medium B~E were larger than medium A like leaf sizes. Leaf length of mustard in medium B~E were significantly longer than medium A. Stem lengths of tomato in medium C~E were about 50cm, which is longer than medium A. Flowering dates were the earliest on 28th of July in medium D, second earliest on 30th of July in medium E. Number of fruits showed no significant difference among medium but was the most in medium E by 8. From the above results, artificial medium made in this experiment was lightweight and had good water-holding capacity compared to existing horticultural medium on sale. It was judged that the most suitable medium for endive, lettuce, mustard, tomato is E (Coco peat:Peat moss:Sphagnum moss=2:5:3) considering growth of vegetables and the physicochemical properties of medium. Keywords: Growth , Lettuce , Lightweight , Tomato , Water holding capacity