33,419 research outputs found
Zeus at HERA II
The ZEUS detector has been upgraded in a number of areas to prepare for the
physics opportunities of HERA II. These upgrades, and their physics rationale
and promise, are briefly outlined. The measurement of polarisation at HERA II,
and its importance for the HERA II physics programme, is also discussed.Comment: 9 pages, 7 figure
Well design as a factor contributing to loss of water from the Floridan Aquifer, eastern Clay County, Florida
A number of wells penetrating the Floridan aquifer in eastern
Clay County were found to be losing water to permeable zones above
this aquifer. A differential in artesian pressure was observed in closely
spaced wells of similar depth. Further investigation. revealed that
the pressure differential in the wells was due to the design of the
wells, of which there were four principal types.
A comparison of the four types of wells in relation to the subsurface
geology showed that three types of wells were open to the permeable
zones above the Floridan aquifer. In such wells water of relatively
high head from the Floridan aquifer moves up through the well bore
and out into zones of relatively low head.
The estimated water loss from poorly designed wells ranged
from 32 to 180 gpm (gallons per minute). The artesian head loss in
leaky wells ranged from 3 to 15 feet. A total loss of water of 39 mgd
(million gallons per day) was estimated from all the leaky wells in
the area.
A significant decline of the piezometric surface of the Floridan
aquifer was observed in eastern Clay County. Some of this decline can
be attributed to the loss of water from the Floridan aquifer through
these poorly designed wells. (Document has 16 pages.
Aeromonas proteolyrica bacteria in aerospace environments
Preflight studies on Aeromonas proteolytica are reported to investigate the possibility of genetic alterations resulting in increased proteolysis in spacecraft environments. This organism may be present on human tissue and could pose medical problems if its endopeptidase and a hemolysin were to be produced in ususually high quantities or altered in such a way as to be more effective in their activities. Considered are: (1) Development of a nutrative holding medium for suspension of organisms; (2) the establishment of baseline information for the standardization of the assay for endopeptidase levels and hemolytic titers; (3) formulation of a method by which intracutaneous hemorrhage could be quantitated in guinea pig tissue; and (4) the responses of these organisms to parameters of spaceflight and experimentation
Lymphoid cell kinetics under continuous low dose-rate gamma irradiation: A comparison study
The mechanism of cell proliferation is studied in the lymphoid tissue of the mouse spleen under the stress of continuous irradiation at a dose-rate of 10 roentgens per day for 105 days. Autoradiography and specific labeling with tritiated thymidine were utilized. It was found that at least four compensatory mechanisms maintained a near-steady state of cellular growth: (1) an increase in the proportion of PAS-positive cells which stimulate mitotic activity, (2) maturation arrest of proliferating and differentiating cells which tend to replenish the cells damaged or destroyed by irradiation, (3) an increase in the proportion of cells proliferating, and (4) an increase in the proportion of precursor cells. The results are compared to previous findings observed in the thymus
The effect of continuous low dose-rate gamma irradiation on cell population kinetics of lymphoid tissue
Cellular response and cell population kinetics were studied during lymphopoiesis in the thymus of the mouse under continuous gamma irradiation using autoradiographic techniques and specific labeling with tritiated thymidine. On the basis of tissue weights, it is concluded that the response of both the thymus and spleen to continuous low dose-rate irradiation is multiphasic. That is, alternating periods of steady state growth, followed by collapse, which in turn is followed by another period of homeostasis. Since there are two populations of lymphocytes - short lived and long-lived, it may be that different phases of steady state growth are mediated by different lymphocytes. The spleen is affected to a greater extent with shorter periods of steady-state growth than exhibited by the thymus
Lymphoid cell kinetics under continuous low dose-rate gamma irradiation: A comparison study
A comparison study was conducted of the effects of continuous low dose-rate gamma irradiation on cell population kinetics of lymphoid tissue (white pulp) of the mouse spleen with findings as they relate to the mouse thymus. Experimental techniques employed included autoradiography and specific labeling with tritiated thymidine (TdR-(h-3)). The problem studied involved the mechanism of cell proliferation of lymphoid tissue of the mouse spleen and thymus under the stress of continuous irradiation at a dose rate of 10 roentgens (R) per day for 105 days (15 weeks). The aim was to determine whether or not a steady state or near-steady state of cell population could be established for this period of time, and what compensatory mechanisms of cell population were involved
Apollo experience report: Data management for postflight engineering evaluation
The Apollo management of data for postflight engineering evaluation is described. The sources of Apollo telemetry data, the control of data processing by a single data team, the data techniques used to assist in evaluation of the large quantity of data, and the operation of the data team before the mission and during the evaluation phase are described. The techniques used to ensure the output of valid data and to determine areas in which data were of questionable quality are also included
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