Ji Changying

General rheological model for natural honeys in China

Abstract The viscosities of 46 varieties of Chinese natural honeys were measured with a rotational viscometer. It is found that the Newtonian model may be considered as the general rheological model for Chinese natural honeys. The relationship among water content, temperature and viscosity for different honeys may be expressed by η = 14·2 × 10 3 exp(−0·31w − 0·085t).

Fuzzy prediction of soil strength based on water content and composition

Sixteen samples representing various paddy field soils of the main rice-planting regions in South China, with their characteristic values, are listed, by which means the soil strength of any other paddy field soil can be fuzzily predicted when its water content, sand content and clay content are given. Illustrative examples show that the result of prediction seems to be acceptable in engineering practice.

Prediction of sinkage for wetland vehicles

Abstract A kind of rheometer is developed by the authors, with which the rheological parameters for paddy soils can be measured in situ. The optimum area of the measuring disk for this apparatus, which is about 38.5 cm2, is determined according to the principle of fuzzy analysis on experimental results, and the effect of impact load is found by experiments. Tests are made with this apparatus for cracked and tyre-wheeled wetland vehicles moving in paddy fields. The predicted and measured sinkages for both vehicles are compared. The results show that for the tracked vehicle, there is not much difference between the predicted and measured sinkages, while for the wheeled vehicle, the predicted sinkages are less than the measured ones, perhaps due to the fact that the slip of the wheel is greater than that of the track, and the sinkage due to slip is quite significant.

Impact of pH Management Interval on Biohydrogen Production from Organic Fraction of Municipal Solid Wastes by Mesophilic Thermophilic Anaerobic Codigestion.

The biohydrogen productions from the organic fraction of municipal solid wastes (OFMSW) were studied under pH management intervals of 12 h (PM12) and 24 h (PM24) for temperature of 37 ± 0.1°C and 55 ± 0.1°C. The OFMSW or food waste (FW) along with its two components, noodle waste (NW) and rice waste (RW), was codigested with sludge to estimate the potential of biohydrogen production. The biohydrogen production was higher in all reactors under PM12 as compared to PM24. The drop in pH from 7 to 5.3 was observed to be appropriate for biohydrogen production via mesophilic codigestion of noodle waste with the highest biohydrogen yield of 145.93 mL/g CODremoved under PM12. When the temperature was increased from 37°C to 55°C and pH management interval was reduced from 24 h to 12 h, the biohydrogen yields were also changed from 39.21 mL/g CODremoved to 89.67 mL/g CODremoved, 91.77 mL/g CODremoved to 145.93 mL/g CODremoved, and 15.36 mL/g CODremoved to 117.62 mL/g CODremoved for FW, NW, and RW, respectively. The drop in pH and VFA production was better controlled under PM12 as compared to PM24. Overall, PM12 was found to be an effective mean for biohydrogen production through anaerobic digestion of food waste.

Relationship between bearing capacity and depth of soft layer of paddy fields in South China

The bearing capacity of paddy field in South China was measured with a kind of penetrometer. A straight line relationship is valuable in summarizing the dependence of bearing capacity on depth of soft soil layer.

Fuzzy clustering of paddy field soils in South China

Abstract Various paddy field soils in South China were measured during the rice-growing season and numerous data were collected concerning soil composition, water content and soil strength. A similarity matrix of 16 samples was constructed, by means of which the soils were clustered at λ = 0.75 into four groups.

Chain-paddle driving mechanism and its pull prediction

In this paper a new driving mechanism for paddy fields, the chain-paddle driving mechanism, is described, and its working principle is explained. Calculations of the pull on each paddle and the total pull on the mechanism are given according to the rheological behaviour of paddy soils. Experiments for a single driving paddle are carried out in a soil bin. The experimental results show that the measured data fit the theoretical ones well.

Effect of Irrigation Methods and Plastic Mulch on Yield and Crop Water Productivity of Okra

Abstract: A field experiment was conducted during 2014-15, aiming to observe the efficiency of irrigation methods and plastic mulch on the yield and crop productivity of Okra. Okra seeds (cv. Subzpari) were grown on ridges with plastic under two different irrigation methods i.e. Every Furrow Irrigation (EFI) and Alternate Furrow Irrigation (AFI). The soil physical properties of ridges being affected by plastic mulched were analyzed before sowing and after harvesting. The results revealed that dry density of soil decreased by 0.03 g cm -3 and 0.04 g cm -3 for AFI and EFI methods, respectively. The total volume of irrigation water applied under AFI method (2169.70 m 3 ha -1 ) was calculated to be half of the total irrigation water applied to EFI method (4340.91 m 3 ha -1 ). Yield obtained under EFI method was 8518 kg ha -1 which was 10.5% greater than yield obtained under AFI method (7621 kg ha -1) and 31.40% when compared with traditional method. The crop water productivity (CWP) for AFI method (3.51 kg m -3 ) was calculated to be greater than CWP obtained under EFI method (1.96 kg m -3 ). The study concluded that both EFI and AFI methods, under plastic mulched ridges practices were beneficial to increase the crop yield with improved crop water productivity.Â

Image Segmentation Technique of Field Cotton Based on Color Threshold

The goal of cotton production in China is to improve corresponding rate of cotton quality grade, foreign fibers, adulteration, and cotton baling inconsistent phenomenon to decrease continuously. With the background, machine vision and pattern recognition technologies are introduced into traditional picking task to discriminate maturity degree and grade of quality of field cotton, which will solve the problem of picking cotton by the way from source, so that various cotton varieties can be adapted, pollution caused by agriculture chemicals can be avoided, labor cost can be reduced and agriculture cost can be decreased. In order to segment field cotton images exactly, we regarded cotton and its background as two classes and segmented them based on their color threshold. A total of 20 000 white, yellow, and stain cotton pixels and 20 000 background pixels of soil and cotton plant, including cotton bracteole, leaf, and branch, were extracted from typical under-ripe cotton images and ripe/over-ripe cotton images with various quality grades from 1 to 7. Color threshold of two classes of cotton and its background pixels were obtained in RGB, HSI, La*b*, and Hunter color space respectively; on the basis of which cotton regions were segmented from images; and HSI and La*b* color spaces were selected respectively by using S below 28, I over 108, L over 118, a* from 123 to 134, b* below 136 with less segmentation noise which would be removed based on morphological filter. The experiment results showed that 907 cotton images were segmented with an accuracy of 87.21% and 86.33% in HSI and La*b* color space respectively. The front images were segmented with an accuracy of 90.83% and 89.98% and the side images with an accuracy of 83.33% and 82.42%. Ripe cotton images were segmented perfectly in HSI color space while under-ripe cotton images in La*b* color space, and the speed-based segmentation method with threshold covering a wide area was preferable for field cotton surroundings.