Strengthening iron enrichment and dephosphorization of high-phosphorus oolitic hematite using high-temperature pretreatment

2020 ◽  
Vol 27 (4) ◽  
pp. 443-453
Author(s):  
Wen-tao Zhou ◽  
Yue-xin Han ◽  
Yong-sheng Sun ◽  
Yan-jun Li
Weed Science ◽  
2011 ◽  
Vol 59 (2) ◽  
pp. 182-187 ◽  
Author(s):  
Grace E-K. Bolfrey-Arku ◽  
Bhagirath S. Chauhan ◽  
David E. Johnson

Itchgrass is a weed of many crops throughout the tropics and one of the most important grass weeds of rainfed rice. Experiments were conducted in the laboratory and screenhouse to determine the effects of light, alternating day/night temperatures, high temperature pretreatment, water stress, seed burial depth, and rice residue on seed germination and seedling emergence of itchgrass in the Philippines. Two populations were evaluated and the results were consistent for both populations. Germination in the light/dark regime was greater at alternating day/night temperatures of 25/15 C than at 35/25, 30/20, or 20/10 C. Light was not a requirement for germination, but a light/dark regime increased germination by 96%, across temperature and population. A 5-min high temperature pretreatment for 50% inhibition of maximum itchgrass germination ranged from 145 to 151 C with no germination when seeds were exposed to ≥ 180 C. The osmotic potential required for 50% inhibition of maximum germination was −0.6 MPa for itchgrass, although some seeds germinated at −0.8 MPa. Seedling emergence was greatest for seeds placed on the soil surface, and emergence declined with increasing soil burial depth; no seedlings emerged from seeds buried at 10 cm. The addition of rice residue to soil surface in pots at rates equivalent to 4 to 6 Mg ha−1reduced itchgrass seedling emergence. Since seedling emergence was greatest at shallow depths and germination was stimulated by light, itchgrass may become a problem in systems where soil is cultivated at shallow depths. Knowledge gained in this study could contribute to developing components of integrated weed management strategies for itchgrass.


1994 ◽  
Vol 339 ◽  
Author(s):  
S. D. Wolter ◽  
B. R. Stoner ◽  
P. C. Yang ◽  
W. Lui ◽  
J. T. Glass

ABSTRACTDiamond nucleation has been investigated on a variety of potential heteroepitaxial substrate materials. Previous work in this laboratory has demonstrated heteroepitaxial nucleation on both Si and SiC substrates via bias-enhanced nucleation (BEN). In this study the effects of BEN of diamond on refractory metal substrates is investigated in detail. Initial data suggest a strong correlation between the carbide forming nature of the substrate material and the rate of nucleation during biasing. Our second avenue of research involves low pressure diamond growth on nickel. This material is a promising material due to its close lattice match and recent evidence of epitaxy reported by other researchers. To form heteroepitaxial diamond on nickel a high temperature pretreatment routine has been established and is the basis for this area of research. The relative importance of hydrogen absorption during this routine is explored and correlated to the formation and degree of diamond epitaxy.


2017 ◽  
Vol 164 ◽  
pp. 284-293 ◽  
Author(s):  
Yani Jiang ◽  
Jiping Zhou ◽  
Qi Zhang ◽  
Guoqi Zhao ◽  
Lin Heng ◽  
...  

2019 ◽  
Vol 62 (5) ◽  
pp. 1293-1298
Author(s):  
Zusongying Zhao ◽  
Klein E. Ileleji ◽  
Diana M. Ramirez Gutierrez ◽  
Zhian Zheng

Abstract. Allicin is the most important active ingredient in garlic because it gives garlic its unique flavor and has a broad spectrum of antibiotic activities. It is also an indicator of garlic product quality. Color can also be used to determine the quality of dehydrated garlic. The allicin content and color of dried garlic are influenced by the processing method, such as pretreatment, and the drying parameters, primarily temperature. To explore the factors that affect the allicin content and color of dried garlic, this study compared the differences in allicin content and color for common pretreatment methods and drying temperatures (35°C for 22 h, 55°C for 12 h, and 75°C for 5 h, to simulate open-sun drying, solar drying, and factory drying, respectively). The results showed that high-temperature pretreatment had a negative effect on the color and allicin retention of dried garlic slices. Cold-water washing and 55°C drying temperature are recommended to produce good garlic color and preserve the allicin content (2.78 mg g-1) to meet both national and international standards. Keywords: Allicin, Color change, Dehydration, Drying, Garlic.


2021 ◽  
Vol 14 (15) ◽  
Author(s):  
Tianshou Ma ◽  
Gongsheng Zhu ◽  
Nian Peng ◽  
Yi Qiu ◽  
Yang Liu ◽  
...  

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