Heat pipe cooling system with sensible heat sink

A heat pipe cooling system which employs a sensible heat sink is discussed. With this type of system, incident aerodynamic heat is transported via a heat pipe from the stagnation region to the heat sink and absorbed by raising the temperature of the heat sink material. The use of a sensible heat sink can be advantageous for situations where the total mission heat load is limited, as it is during re-entry, and a suitable radiation sink is not available

Application of heat pipes to a nuclear aircraft propulsion system

Application of heat pipes to nuclear aircraft propulsion syste

Endocytic uptake of particles by mononuclear phagocytes and the penetration of obligate intracellular parasites

As William Trager pointed out some time ago in a review in 'Science', all obligate intracellular parasites--be they viral, bacterial, or protozoan--face a common dilemma. That dilemma is to invade their host cells in a way that is not destructive of the host cell upon whose metabolic hospitality and functional well-being their own reproduction depends. Simply stated, these organisms must penetrate the plasma membranes of their host and take up residence in a suitable location in the cell's cytoplasm. Since many of the speakers in this session will address them selves to the issues of penetration and intracellular location of specific organisms, I view my task as one of trying to place these issues into a general conceptual framework

How Teaching Matters

Silverstein writes a letter to the editor of CBE Life Science Education in response to Harold Wenglinsky's paper “How Teaching Matters: Bringing the Classroom Back into Discussions of Teacher Quality” (www.ets.org/research/pic) which analyzes how the attributes and classroom practices of teachers affect the performance of eighth-grade students on standardized tests in science. Wenglinsky identified teacher attributes and practices that are highly correlated with superior student achievement. Two of the four attributes and practices identified by Wenglinsky (i.e., teacher laboratory skills and implementation of hands-on classroom exercises) are the central focus of Columbia University's Summer Research Program for Science Teachers (www.scienceteacherprogram.org) and of other Science Work Experience Programs for Teachers. Data to be published elsewhere show that teacher participation in Columbia's program has a very positive impact on their students' success in passing a New York State Regents exam in science. Confirmation of Wenglinsky's postulates could greatly simplify the task of improving middle and high school science education. For this reason alone, it is important to test Wenglinsky's conclusions rigorously and soon

Commercial Law—Provision in Stop Payment Order Releasing Bank from Liability for Negligence Against Public Policy

Thomas v. First Nat. Bank of Scranton, __ Pa. __, 101 A. 2d 910 (1954)

A feasibility study of heat-pipe-cooled leading edges for hypersonic cruise aircraft

A theoretical study of the use of heat pipe structures for cooling the leading edges of hypersonic cruise aircraft was carried out over a Mach number range of 6 to 12. Preliminary design studies showed that a heat pipe cooling structure with a 33-in. chordwise length could maintain the maximum temperature of a 65 deg sweepback wing with a 0.5-in. leading edge radius below 1600 F during cruise at Mach 8. A few relatively minor changes in the steady-state design of the structure were found necessary to insure satisfactory cooling during the climb to cruise speed and altitude. It was concluded that heat pipe cooling is an attractive, feasible technique for limiting leading edge temperatures of hypersonic cruise aircraft

A study of heat pipe applications in nuclear aircraft propulsion systems Final report

Heat pipes for nuclear aircraft propulsion system

Heat pipe cooling for scramjet engines

Liquid metal heat pipe cooling systems have been investigated for the combustor liner and engine inlet leading edges of scramjet engines for a missile application. The combustor liner is cooled by a lithium-TZM molybdenum annular heat pipe, which incorporates a separate lithium reservoir. Heat is initially absorbed by the sensible thermal capacity of the heat pipe and liner, and subsequently by the vaporization and discharge of lithium to the atmosphere. The combustor liner temperature is maintained at 3400 F or less during steady-state cruise. The engine inlet leading edge is fabricated as a sodium-superalloy heat pipe. Cooling is accomplished by radiation of heat from the aft surface of the leading edge to the atmosphere. The leading edge temperature is limited to 1700 F or less. It is concluded that heat pipe cooling is a viable method for limiting scramjet combustor liner and engine inlet temperatures to levels at which structural integrity is greatly enhanced

THE PENETRATION OF REOVIRUS RNA AND INITIATION OF ITS GENETIC FUNCTION IN L-STRAIN FIBROBLASTS

Reovirus type 3 is phagocytized by L cells and rapidly sequestered inside lysosomes. Hydrolases within these organelles are capable of stripping the viral coat proteins, but they fail to degrade the double-stranded RNA genome. These observations support the view that sojourn of reovirus in lysosomes, when the lytic enzymes uncoat its genome, is an obligatory step in the sequence of infection. Although the mechanism for transferring the uncoated RNA out of lysosomes remains to be elucidated, evidence is presented suggesting that progeny genomes are bound to site(s) possessing the fine structure of viral inclusions or factories. It appears that both the synthesis of single- and double-stranded viral RNA and the morphogenesis of progeny virus particles occur in such factories