Search

Ice formation and accumulation on surfaces can cause operational risks and failure to various engineering structures and systems. Liquid repellent surfaces could reduce ice accretion and improve asset integrity and safety in harsh environments. This article examines how surface wettability affects water droplet impact and freezing on a surface. It presents experimental results of water droplet impact and freezing on horizontal and inclined stainless-steel surfaces with varying wettabilities achieved through microscale texturing and coating. The water droplets are at 5 °C before impacting on the target surfaces and the diameter of the droplets ranges from 1.80 mm to 4.11 mm. The static contact angles of water droplets on the surfaces range from 77° to 145° and the surface temperatures vary from −10 °C to −13 °C. The droplet impact speed ranges from 0.77 m/s to 1.17 m/s. In addition, all experiments are conducted under approximately the same room air temperature and relative humidity of 15 °C and 30% respectively. It is found that the surface and water droplet properties, along with its impact velocity, affect the droplet dynamics after impacting on the surface, which in turn affects the heat transfer and the freezing process. The results demonstrate that water droplets spread less and oscillate longer on more hydrophobic surfaces, which leads to a delay of freezing and significantly longer total icing time due to the lower heat transfer rate caused by less contact between the liquid and the surface. A two-stage droplet freezing process is observed through high-speed imaging. A small tip forms at the top of the droplet when it is completely frozen. The contribution of droplet volume (larger droplets need a longer freezing time) is found to be more significant than the effects of droplet dynamics (larger contact areas cause a shorter freezing time). On an inclined surface, the droplet shows a gliding and stretching process. The total icing time decreases at higher inclinations due to the increased contact areas. This paper demonstrates an icing delay with water repellent surfaces on engineering metals such as stainless steels.

An extreme high temperature during grain filling is an important environmental factor that reduce the yield and quality of rice. In this study, we compared the grain appearance, composition and starch structure of four rice varieties response to high temperature during grain filling. The results obviously revealed that two indica AUS varieties Halwa and Jamir showed more tolerance to high temperature during grain filling than either the japonica Nipponbare or another AUS rice DJ24. The data showed that Halwa and Jamir presented less chalkiness, less grain weight loss, less change of endosperm components as well as starch structure than Nipponbare and DJ24 under high temperature treatment. Hence, the results implied that Halwa and Jamir might be useful targets to further identify genetic mechanism response to high temperature, at least during grain filling and endosperm development. Moreover, these AUS varieties have potential application value in further breeding of rice with good quality and heat tolerance.

This paper traces the history of China Scientific and Technical Papers and Citations database (CSTPC) since its founding in 1988. The fact that most Chinese scientists publish their research results in Chinese journals requires that China establish SCI counterparts dedicated to domestic S & T journals. The article describes the selection criteria for source journals, the approach used to adjust the structure of source journals, the criteria for selecting items to be included in the database, and the indexing method. Then it discusses the impact upon government R & D administration agencies and the science community in general by both CSTPC team and CSTPC database. Finally, the article analyzes the main factors that lead to the primary success of CSTPD. The authors encourages information workers in other non-English developing countries to build up similar databases.