2,114 research outputs found
Low scatter lightweight fission spectrometer constructed for biological research
Low scatter, lightweight fission spectrometer provides a simple, reliable method for determining absolute neutron fluxes in a fixed neutron. It minimizes neutron scatter and energy degradation effects, and has a counting volume large enough to intercept the most energetic fission fragments, yet small enough to be discriminating
Computer grading of examinations
A method, using IBM cards and computer processing, automates examination grading and recording and permits use of computational problems. The student generates his own answers, and the instructor has much greater freedom in writing questions than is possible with multiple choice examinations
Uranyl phthalocyanines show promise in the treatment of brain tumors
Processes synthesize sulfonated and nonsulfonated uranyl phthalocyanines for application in neutron therapy of brain tumors. Tests indicate that the compounds are advantageous over the previously used boron and lithium compounds
Simple colorimetric method determines uranium in tissue
Simple colorimetric micromethod determines concentrations of uranium in tissue. The method involves dry ashing organic extraction, and colorimetric determination of uranyl ferrocyanide. This uranium determination technique could be used in agricultural research, tracer studies, testing of food products, or medical research
Ceric and ferrous dosimeters show precision for 50-5000 rad range
Ammonium thiocyanate, added to the usual ferrous sulfate dosimeter solution, yielded a very stable, precise and temperature-independent system eight times as sensitive as the classical Fricke system in the 50 to 5000 rad range. The ceric dosimeters, promising for use in mixed radiation fields, respond nearly independently of LET
Rapid analytical determination of glutaraldehyde concentrations
Technique utilizes the iodimetric procedure which adds unknown excess of bisulfite to glutaraldehyde /GA/ then titrates unreacted bisulfite with standard iodine isotope to determine GA concentrations. Technique may interest microscopists, food researchers, biochemical or medical laboratories, and drug manufacturers
Mobility Monitoring System For Ecological Studies
Radioactive-nuclide system automatically monitors animals in the field, using radioactive tracers affixed to the animals, Geiger-Muller tube radiation detectors, and event-recorders. Four animals can be monitored simultaneously within a 32-m circle, with each animal as far as 1 m from its associated detector
Extending higher dimensional quasi-cocycles
Let G be a group admitting a non-elementary acylindrical action on a Gromov
hyperbolic space (for example, a non-elementary relatively hyperbolic group, or
the mapping class group of a closed hyperbolic surface, or Out(F_n) for n>1).
We prove that, in degree 3, the bounded cohomology of G with real coefficients
is infinite-dimensional. Our proof is based on an extension to higher degrees
of a recent result by Hull and Osin. Namely, we prove that, if H is a
hyperbolically embedded subgroup of G and V is any G-module, then any n-quasi
cocycle on H with values in V may be extended to G. Also, we show that our
extensions detect the geometry of the embedding of hyperbolically embedded
subgroups, in a suitable sense.Comment: Minor revisions. This version has been accepted for publication by
the Journal of Topolog
Neutron therapy of cancer
Reports relate applications of neutrons to the problem of cancer therapy. The biochemical and biophysical aspects of fast-neutron therapy, neutron-capture and neutron-conversion therapy with intermediate-range neutrons are presented. Also included is a computer program for neutron-gamma radiobiology
Vortex Developments Over an Accelerated Airfoil at High Angles of Attack
Proper control of unsteady separated flow developments over the lifting surfaces of an aircraft may prove to be an effective method of enhancing aerodynamic lift and producing better aircraft performance. Due to the complexity of unsteady flow separation and subsequent flow developments, experimental exploration and observation are essential in providing a source for comparison and verification with theoretical and computational models. In light of these motivations, a new experimental system that is capable of generating wide of range of unsteady flow histories has been developed and employed to visualize flow developments over an airfoil in accelerated-decelerated motion. The paper presents a description of the experimental system and its use in investigating accelerating flow over a flat plate airfoil at high angles of attack. The experimental results reported in the paper may serve as a useful source to guide and verify computational research efforts that are currently in progress
- …