22 research outputs found
A TEMPERATURE DISTRIBUTION ANALYSIS ALONG A THERMAL RADIATING FIN OF NONUNIFORM THICKNESS
The general differential equation of a thermally radiating fin is presented for the situation of a uniform heat source along the base of the fin. An electronic analog solution of a fin of nonuniform thickess with one- dimensional steadystate radiant heat transfer is presented. The specific example is concerned with a constant rate of variation of thickness; however, any general configuration could be used. (auth
A LUNAR POWER PLANT
A concept of a nuclear power plant to be assembled on earth and operated on the moon is presented. The two principal design objectives are reliability and high specific power. Wherever there is an incompatibility between these two objectives, the decision favors reliability. The design is based on the premise that the power plant must be designed on the basis of current technology and with a minimum amount of research and development. The principal components consist of a fast reactor in a direct cycle with a mercury-vapor turbine. The high- frequency generator, hydrogen compressor for the generator cooling system, mercury-recirculating pump, and condensate pump are on an extension of the turbine shaft. Ths mercury vapor is condensed and the hydrogen cooled in wing radiators. The reactor is of a construction quite similar to EBR-I Mark IlI for which there is a large amount of operating experience. The radiator is a vertical tube-and-fin type built in concentric cylindrical sections of increseing diameter. The curved headers are connected by swivel joints so that, upon arrival, the radiator can be quickly unfolded from the compact cylindrical package it formed during transportation. (auth
Knowledge-based energy functions for computational studies of proteins
This chapter discusses theoretical framework and methods for developing
knowledge-based potential functions essential for protein structure prediction,
protein-protein interaction, and protein sequence design. We discuss in some
details about the Miyazawa-Jernigan contact statistical potential,
distance-dependent statistical potentials, as well as geometric statistical
potentials. We also describe a geometric model for developing both linear and
non-linear potential functions by optimization. Applications of knowledge-based
potential functions in protein-decoy discrimination, in protein-protein
interactions, and in protein design are then described. Several issues of
knowledge-based potential functions are finally discussed.Comment: 57 pages, 6 figures. To be published in a book by Springe
Pooled analysis of prognostic impact of urokinase-type plasminogen activator and its inhibitor PAI-1 in 8377 breast cancer patients
BACKGROUND: Urokinase-type plasminogen activator (uPA) and its inhibitor
(PAI-1) play essential roles in tumor invasion and metastasis. High levels
of both uPA and PAI-1 are associated with poor prognosis in breast cancer
patients. To confirm the prognostic value of uPA and PAI-1 in primary
breast cancer, we reanalyzed individual patient data provided by members
of the European Organization for Research and Treatment of Cancer-Receptor
and Biomarker Group (EORTC-RBG). METHODS: The study included 18 datasets
involving 8377 breast cancer patients. During follow-up (median 79
months), 35% of the patients relapsed and 27% died. Levels of uPA and
PAI-1 in tumor tissue extracts were determined by different immunoassays;
values were ranked within each dataset and divided by the number of
patients in that dataset to produce fractional ranks that could be
compared directly across datasets. Associations of ranks of uPA and PAI-1
levels with relapse-free survival (RFS) and overall survival (OS) were
analyzed by Cox multivariable regression analysis stratified by dataset,
including the following traditional prognostic variables: age, menopausal
status, lymph node status, tumor size, histologic grade, and steroid
hormone-receptor status. All P values were two-sided. RESULTS: Apart from
lymph node status, high levels of uPA and PAI-1 were the strongest
predictors of both poor RFS and poor OS in the analyses of all patients.
Moreover, in both lymph node-positive and lymph node-negative patients,
higher uPA and PAI-1 values were independently associated with poor RFS
and poor OS. For (untreated) lymph node-negative patients in particular,
uPA and PAI-1 included together showed strong prognostic ability (all
P<.001). CONCLUSIONS: This pooled analysis of the EORTC-RBG datasets
confirmed the strong and independent prognostic value of uPA and PAI-1 in
primary breast cancer. For patients with lymph node-negative breast
cancer, uPA and PAI-1 measurements in primary tumors may be especially
useful for designing individualized treatment strategies
TESTING OF CONTAINMENT CAPABILITIES OF REINFORCED CONCRETE-SHIELDED ENCLOSURES
A reinforced concrete-shielded enclosure intended to contain nuclear reactor experiments was subjected to internal pressures up to 10 psig. The strains in reinforcing steel were measured with strain gages at critical locations for each pressure increment. These strains were compared with calculated strains; good agreement was found if the appropriate stress- concentration factors are applied at locations near re-entrant corners and wall openings. Leakagerate tests were performed to disclose the ability of an ordinary thick-walled concrete cell to contain compressed gases. Observed leak rates are given for the two twin cells, before and after the inside surfaces were painted. (auth
ENGINEERING APPLICATIONS OF ANALOG COMPUTERS
Six experiments from the fields of reactor engineering, heat transfer, and dynamics are presented to illustrate the engineering applications of analog computers. The steps required for producing the analog solution are shown, as well as complete information for duplicating the solution. Graphical results are provided. The experiments include: deceleration of a reactor control rod, pressure variations through a packed bed, reactor kinetics over many decades with thermal feedback, a vibrating system with two degrees of freedom, temperature distribution in a radiating fin, temperature distribution in an infinite slab considering variable thermal properties, and iodine -xenon buildup in a reactor. (M.C.G.