An evacuated tubular solar collector was fabricated from acrylics for improved resistance to shattering. A plasmatron was employed to apply a thin gas-barrier coating to the surfaces of the plastic tube to prevent/alleviate gas infiltration. Experiments were conducted to investigate the effect of vacuum level on the performance of the non-glass vacuum-tube solar collector. Inserted in the evacu...

Wet-collector systems, designed and operated for air-pollution control without concern for or con­ sideration of the stream-pollution effects of their liquid-borne wastes, may cause significant localized pollution of surface and ground water bodies. Wet­ collector systems can be designed with presently known technology to decrease contaminants in effluent outfalls to acceptable levels. Increasi...

Many garbage collectors on parallel computers are written in sequential languages, therefore thay are not portable across machines with different communication primitives. Moreover, the description of garbage collectors on distributed memory machines, which use asynchronous messages, is complex. We implemented a garbage collector for parallel object-oriented language Schematic by using Schemati...

Our research is concerned with compiler-independent, tag-free garbage collection for the C ++ programming language. This paper presents a mark-and-sweep collector , and explains how it ameliorates shortcomings of a previous copy collector. The new collector, like the old, uses C ++ 's facilities for creating abstract data types to deene a tracked reference type, called roots, at the level of th...

The degenerative radical addition-transfer of xanthates onto alkenes allows the rapid assembly of richly functionalized structures. Various families of open-chain, cyclic, and polycyclic compounds can thus be readily accessed. Furthermore, the process can be extended to the synthesis or modification of aromatic and heteroaromatic derivatives by exploiting the possibility of using peroxides both...

Highly ordered mesoporous CdS nanowire arrays were synthesized by using mesoporous silica as hard template and cadmium xanthate (CdR(2)) as a single precursor. Upon etching silica, mesoporous CdS nanowire arrays were produced with a yield as high as 93 wt%. The nanowire arrays were characterized by XRD, N(2) adsorption, TEM, and SEM. The results show that the CdS products replicated from the me...

Along with the prevalence of email, a number of free email managers have been developed to assist people to deal with personal and interpersonal affairs. Beside sending and receiving email, they provide a diversity of function such as memorandum and calendar. Many researchers are interested in how people communicate via email. They may have questions such as " how long does it take them to repl...