The following report was made to determine the effective clarity improvement, flow rate characteristics, and operational problems encountered on passing Redox uranium feed solution through sintered, modified Type 304 stainless steel filter elements.

From introduction: "This is the ninth monthly report, BMI-514, under Contract No. AT(30-1)-771 on "Zirconium Research and Development". The report covers the work period from September 15, 1950, to October 15, 1950. Work is continuing on the preparation of large-diameter zirconium crystal bars in the 16-inch-diameter de Boer unit. Crystal bars up to 1-5/16 inches in diameter and 8 feet long have been prepared in this unit."

The following report discusses direct recording of nuclear pulse height data on magnetic tape that represents an inexpensive method of data storage where some degradation of the original energy resolution can be tolerated.

The following report describes a successful procedure used for the determination of americium in the presence of plutonium. Provided are articles listed that describe the research done in developing the method.

"An apparatus was designed and fabricated to obtain film samples from irradiated process slugs. This apparatus has been used to obtain film samples from slugs of the sodium dichromate elimination test."

This report follows experiments concerned with a particular proposal or set of related proposals of means for the production of plasma with density above 10-11 particles per cm-3 with a temperature of the order of a few electron volts.

Report discussing the preparation, stability, and recommended storage of cobalt trifluoride. "Cobalt trifluoride prepared by the action of fluorine upon anhydrous cobalt dichloride remains stable when kept in sealed glass tubes but on exposure to air it absorbs water and its use in the conversion of T3O8 to TF6 cannot be relied upon..."

A research program is being conducted to obtain experimental data in the irradiation of plutonium-enriched fuel to confirm a theoretical model for predicting isotopic composition and reactivity changes in plutonium-enriched, light-water-moderated reactors. Quarterly progress: The densitometry procedure (for measurement of alpha autoradiographs of fuel pellets) has been modified to eliminate the need for a second emulsion. The existence of a problem of latent image fading and non-reciprocity of the high-resolution emulsion has been recognized. A tentative procedure has been worked out to correct these emulsion difficulties. the number of polished pellets has been increased to thirteen. The number of hot spots per pellet has not changed appreciably. The largest spot seen is irregular with an estimated volume equivalent to that of a sphere of 35 mil diameter with a PuO2 concentration in the neighborhood of 60%. The VBWR irradiation run now under way is not scheduled to end until October. To the end of the last run the cumulative exposure reached 3703 MWD/T, as logged by VBWR operating personnel. Applying the same scale factor between logged exposure and Ce-Cs analysis of the first fuel sample gives a corrected exposure of 4416 MWD/T. Further debugging of EPITHERMOS, the epithermal extension of …

Activities in a program to develop techniques in the use of pulsed neutron sources to measure shutdown parameters related to large thermal power reactors are reported. The development of pulsed neutron source techniques for large power reactors has led to a new theoretical model recently developed by E. Garelis and J.L. Russell, Jr. The theory is presently based on a bare, one-group model with m-delayed precursors and takes all spatial modes into account. Results indicate, however, that the application of this model is much broader. Experiments were designed and carried out to both verify this new theory and to demonstrate the performance of the experimental hardware in a large power reactor.

Summary: A prototype control rod containing absorber plates made from an electro- deposited dispersion of boron carbide in nickel was tested in the VBWR. It was exposed to the reactor environment of 545 degree F boiling water and thermal neutron fluxes (perturbed) which ranged from 0.6 to 1.1 x 10/sup 13/ nv for 2236 hours over a period of six months. The maximum B/sup 10/ burnup achieved during the test period was 1.8 percent. After irradiation, the rod was examined. The results of the examination are summarized below: (1) The B/sub 4/C-- Ni plate assembly did not undergo significant dimensional changes during irradiation. (2) Numerous blisters developed on both the outer and inner surfaces of three of the four plates. Blistering was more severe on the outer surface than on the inner, and was most severe in a large region located in the lower half of plate 4. Metallographic examination revealed that the blisters were located only in the 2- mil protective nickel overlay covering the B/sub 4/C-- Ni dispersion. It was concluded that they formed from the buildup of gas pressure at the Ni: Ni-- B/sub 4/C interfaces, rather than from corrosion attack. Helium from the B/sup 10/(n alpha …

"A finite difference approximation to a non-linear set of parabolic differential equations arising in shallow water theory is given. These difference equations were used to determine the shape and rate of propagation of a hum of fluid down a channel of constant depth. The hump of fluid was found to spread instead of steepen, as is the case in the usual shallow water theory."

"The problems of sequencing jobs through machines are discussed in a linear graph framework. The construction of feasible schedules from given technological orderings is related to the construction of transitive graphs from given component graphs. Methods of constructing transitive graphs are given and bounds on the number of different transitive graphs constructed from given components are determined. A recursive convex function defined on the transitive graphs-the job operation completion time and schedule time-is studied. Bounds on the number of different values that the schedule time can attain is obtained. Examples of multiprogramming, flow shop and machine shop scheduling are studied."

In the fall of 1952, a pilot plant batch dissolution study was carried out to obtain the data required for the design of the Purex Plant dissolvers. Particular emphasis was placed on the rate of dissolution and the efficiency of nitrogen oxide recovery from the dissolver off-gas. The results are presented in this report.

Project Sherwood is a nation-wide attempt to produce a controlled thermo-nuclear fusion reaction. The Astron experiment, conceived by Nicholas Christofilos, will utilize the effects of a cylindrical layer of relativistic electrons to contain and heat the plasma. A high quality, 200-ampere, 5-Me V electron beam is required to form the electron layer. The electron beam is produced by a linear induction electron accelerator. Three hundred and thirty-three toroidal cores of magnetic material surround an evacuated ceramic accelerating column. The electrons are accelerated by the transverse electric field produced by the changing flux. The magnetic cores are tape-wound toroids of .001", 50% Ni - 50% Fe. Two hundred eighty-eight cores are 24" o.d. x 8-1/2" i. d. x 1/2" thick and the remaining forty-five are 33" o. d. x 18" i. d. x 1/2" thick. Each core is required to support 16 kG for 0.4 psec. The choice of magnetic material was made by testing all available material for the required parameters. Results of these tests are presented.

The duration of mitosis is of great importance in an evaluation of growth rates in proliferating somatic tissues, since calculations are based on observations of mitotic activity, and therefore final results are directly proportional to an assumed value for mitotic time. This duration cannot be measured directly in vivo at a tissue level, since the mode of distribution of the single cell value is not known. This difficulty is not overcome in extrapolations from in vitro measurements. Also it is not overcome with the labeling of proliferating cells after tritiated thymidine injection in vivo if subsequent observation is limited to the rate of progression into mitosis of labeled cells that incorporated the tracer during the period of DNA-synthesis. Observation of separate mitotic phases, however, offers the possibility of following the progression of the wave of labeled cells at successive, short-lasting checking steps, and to analyze the variability in the times of passage through mitosis. In the present work, the progression of labeled cells as a function of time, after a single injection of tritiated thymidine, was followed in successive phases of mitosis in erythroblasts of dog bone marrow.

Studies on a large variety of plant species, particularly by Sparrow and his colleagues, have shown that radiosensitivity, as measured by growth inhibition and lethality, is strongly correlated with various parameters of the cell nucleus. Foremost among these are nuclear volume, SNA content and chromosome number. It is generally accepted that in proliferating cell systems chromosome damage may well be the principal radiobiological lesion, and the observed correlations are in line with the contention that loss of genetic materials following such fragmentation is a factor of a major importance in radiation-induced lethality and growth inhibition in plants.

The development of nuclear arms added the effects of ionizing radiation to the direct and indirect mechanical, chemical or thermal hazards of "conventional" weapons. The biological effects of ionizing radiation are the result of absorption of energy and the morphologically recognizable damage is poorly understood. Although new in their use in weapons and difficult to evaluate in their consequences, ionizing radiations are by no means new to physicians. Furthermore, medical experience has shown that clinical consequences of radiation injury are similar to those with which the clinician has to deal with every day in the treatment of neoplastic disorders and its complications. Soon after the discovery of x-rays by Roentgen and of the phenomenon of radioactivity by Bequerrel in the last decade of the last decade of the 19th century, it was found that ionizing radiation can produce marked biological effects by interfering with cell- and organ functions. Senn and Hussey were the first to effectively treat leukemia by this means. This, since about 60 years, ionizing radiation has been a powerful tool in the hands of physicians both in diagnostic procedures and for therapy of malignant disease. It should not be forgotten however, that the price paid for this …

Binary fluorides of the type XMnF3 (X= Na, Rb, Cs, and NH4), which were investigated previously by means of x-ray, electron spin resonance specific heat, and magnetization measurements, have been reported to be antiferromagnetic. The present study reports powder neutron diffraction measurements on these compounds undertaken to confirm the antiferromagnetism and to study details of the magnetic ordering. Some information was also obtained concerning the nuclear structures.

The scope of the AGS complex has expanded rapidly during the three years since an accelerated beam was first obtained. Demand for research time far exceeds the amount available although facilities have been much increased. At the same time, experiments are being designed which are more complicated than previous ones and which make more stringent demands on the accelerator and on its auxiliary equipment. There is a continuous trend of experiments to particle beams of greater momentum, as the experimental techniques are refined. This use of increased momentum means that larger areas are required for the apparatus and that more power is necessary for the magnetic optics. All beam-sharing at the AGS is done by multiple use of each accelerated pulse because our experience indicates that pulse-by-pulse beam-sharing is relatively inefficient. (Expansion chambers have seldom been used at the AGS.) The problems of scheduling experiments becomes increasingly complex since combinations must be found satisfying the criteria: maximum number of experiments to run simultaneously; minimum downtime to be taken for rearrangement between successive experimental arrays

The crystal structure of MgSO4·4H2O has been refined using single crystal neutron diffraction data for the three main zones. The hydrogen positions which were found are essentially those which have been deduced from X-ray data in an earlier investigation.The mean value of the O-H bond lengths is 0.97Å. The O-H-O bonds are bent considerably. One hydrogen atom does not participate in hydrogen bonding, as can be concluded from the geometry of its surroundings and its thermal motion.

In high-energy particle physics the initial problem is to obtain information about the behavior of particles which are invisible by any known means (the radius of a proton is 10-13 cm) and which may be traveling at speeds greater than 180,000 miles per second, but at less than the speed of light. Some of the work is being done with the use of electronic counters, but the larger fraction is currently done by three techniques which employ the photographic process. These are the silver halide emulsion stack, the liquid hydrogen bubble chamber and the spark chamber. Counters provide immediate information but it is of a yes-or-no character, whereas the other methods are capable of actually mapping, with varying degrees of accuracy, an interaction between particles. The emulsion stack is quite familiar and need be discussed only briefly. Since individual silver halide crystals are rendered developable along the paths of charged particles, a sensitive detector may be built up with thick layers of specially sensitized emulsion having no base support. As the path of the particle may be through several emulsion having no base support. as the path of the particle may be through several emulsion layers and the track must …

A feedback technique has been developed to equalize the DC levels of two signal sources so that AC signal components which are much smaller than the DC levels can be compared accurately without introducing a low frequency cut-off and consequent rate-dependency into the system. A digital integrator in the feedback loop provides a highly stable long-term "memory" so that the correct level will be maintained during intervals when the signals are "frozen" at some arbitrary point.

In the vast field of radiation pathology we find pathologists, anatomists, and even physiologists busily at work, but the radiobiologist is conspicuously absent, although, according to Zirkle (1959), this field is clearly within his domain. Perhaps it is wise to take this broad hint of the scientifically so well equipped radiobiologist and to stay clear from an area in which an incalculable array of variables makes clearcut experimentation a hopeless venture, a priori. Perhaps it would be better if the pathologist, who must study pertinent material, restricts himself humbly to the recording of his observations, refraining from any attempt at interpretation. On the other hand, since seemingly audacious speculation has borne fruit in the past and the value of the information that results, if the speculation proves to be correct, is worth many times the effort, there is obvious justification for a thesis on the mechanism of delayed radionecrosis.

Evidence is rapidly accumulating that the genetic material carried in a chromosome is arranged in a highly organized manner. The nucleotides of DNA constituting a gene are grouped in sequence, like the letters of a word, and presumably each word uniformly consists of three letters. Successive words make up a sentence containing the information needed to build a protein molecule. Each word of the sentence is transcribed to form an amino acid of the protein for which the particular gene is responsible.