The purpose of this study was to investigate mathematically the concentration decrease due to particle deposition phenomena in highly concentrated monodispersed aerosols (mean particle size less than 1.0 mu) flowing through ventilation ducts. It was found that, from the standpoint of removal, the decrease in concentration due to deposition on duct walls was insignificant; but, when considering contamination on duct walls, the amount deposited, even though small when compared with the amount in the bulk stream, should not be overlooked.

This technical report describes development work done on method of particle separation by the Biology Division of the Oak Ridge National Laboratory and the Oak Ridge Gaseous Diffusion Plant during the period January 1 to June 30, 1963, under the Joint National Institute for Health-Atomic Energy Commission Zonal Centrifuge Development Program. The central effort has been to develop zonal centrifuge systems for the separation of cells and sub-cellular particles, including viruses, and bio-colloids, including proteins and nucleic acids.

This technical report describes development work done on zonal centrifuge systems at the Oak Ridge National Laboratory and the Oak Ridge Gaseous Diffusion Plant during the period July 1 to December 31, 1962 under the Joint National Institute for Health-Atomic Energy Commission Zonal Centrifuge Development Program. A basic purpose of this project is to develop new methods for isolating virus particles associated with cancerous cells and tissues. Three classes of rotor systems capable of separating particles ranging in size from whole animal or plant cells to protein or nucleic acid molecules on the basis of either sedimentation rate or density alone have been developed. Experiments with phage particles indicate the feasibility of large-scale virus isolation by continuous-flow centrifugation, followed by isopycnic banding in cesium chloride and velocity sedimentation in sucrose - all steps being carried out sequentially in the same rotor. Zonal rotors using the reorienting gradient principle for molecular separations have been tested to 141,000 rpm (formula). Previous work on zonal centrifugation and future plans for this program are discussed.

In early 1961 a Target Fabrication Center was established at Oak Ridge National Laboratory to carry out the routine preparation of a wide variety of targets and to provide research and development support to the target program. Although most of the effort concerned enriched stable isotopes, both normal and radioactive materials are also handled. With the aid of rolling mills, resistance-heat and electron-bombardment vacuum evaporation, presses, and electroplating equipment, targets of elements and compounds are prepared which cover a broad range of thicknesses and sizes, in both supported and self-supporting forms. Thicknesses vary from a few micro-inches to dimensions limited in many cases only by the amount of material available. Although there are certain limitations imposed by the chemical reactivity, the development effort is supporting targets of most elements and compounds.

Technical report on the activities of the Oak Ridge National Laboratory Biology Division for the report period including a list of 346 publication and lectures and 205 short articles by members of the division on their research and activities.

This bibliography represents the first cumulative edit of the literature examined by the Radiation Shielding Information Center recently established at the Oak Ridge National Laboratory. Its two major sections consist of a list of documents by subject category and of an author index. The document list covers nine major subjects with a total of 118 categories; however, literature specimens have not yet been entered for all categories. If a document applies to more than one category, it is listed under each. The author index includes cross references to the categories under which each author's publications appear. Preceding the bibliography is a list of the subject categories, their corresponding category numbers and the pages on which they appear in the bibliography,

As part of the thermonuclear effort at Oak Ridge National Laboratory, large volume high-beta plasmas have recently been produced by microwave power at the electron-cyclotron frequency. The original work was done with 13-cm microwave radiation in a magnetic mirror and was reported at Salzburg. Since that time, higher frequency and higher power radiation has been used in a succession of experiments. The current experiments involve heating a plasma in the EPA Facility which has a 3:1 magnetic mirror ratio. Up to 50-kw CW of 3-cm microwave power are applied to the plasma in a large volume cavity.

The experimental program at the Oak Ridge National Laboratory into the thermal and hydrodynamic characteristics of boiling alkali liquid metals has been continued without essential changes in either scope or direction. While all aspects of the work are being pursued, this report is concerned only with those portions of these studies involving convection boiling with potassium. This report has two sections: (1) Forced-convection experiments; and (2) Superheat studies.

In a sense, the whole process of differentiation is one of directed functional mosaicism. It is, however, the accidental or random juxtaposition in the same organism of cells having actually or effectively different genotypes that is generally thought of as true mosaicism. The study of this condition constitutes a perfect meeting place for the fields of genetics and developmental biology, providing, as it does, interrelated information on mutability, cell lineage (including the special problems of cell lineage of the germ line), and the effect of genotype on part of the organism versus the whole. The discovery in recent years that most or all of one X chromosome of the normal mammalian female become randomly inactivated early in development, an event that leads to functional mosaicism, provides us with a great potential tool for the study of gene action. The present paper will attempt to bring together results of diverse observations and experiments (many of them as yet unpublished) bearing on both genetic and functional mosaicism in the mouse.

The potential of the thorium fuel cycle for achieving low nuclear fuel costs is complicated by the presence of 232U associated with 233U formed in the reactor. The decay of the 232U daughters produces penetrating radiation making the consideration of shielding and fast process times mandatory. The construction and operation of a lightly shielded, semi remote factify, known as the Kilorrod Facility, in which fuel rods containing (Th-3 wt % 233U)O2 are fabricated, is the first step in determining the technical feasibility and economy of the thorium fuel cycle. This facility, which is presently operating at the Oak Ridge National Laboratory, was designed to fabricate fuel rods that will be user in zero-power, criticality experiments at the Brookhaven National Laboratory. The fuel rods are produced by vibratory compaction of sogel produced oxide in Zircaloy-2 tubes to near 90% of the theoretical density of the powder. The facility was designed to produce 10 rods/day; however, the attainment of the production rate was secondary to the collection of engineering data on the process itself.

This paper summarized the work at ORNL in controlled-potential dc polarography since mid 1959 and states conclusion and viewpoints that have been reached in the course of this work. The following topics are discussed: (1) Potentiostatic Compensation for Polarographic Cell Resistance; (2) Time-Derivative DC Polarography; (3) Signal-to-Noise Ratio (S.N); (4) Resolution; and (5) DC Polarography in Non Aqueous Solvents and, Particularly, in Solvent Extracts.

Five recent investigations of the critical heat flux in water systems are described. These studies were conducted in the interval from early 1963 through the present. The five studies are (1) Pool studies: inherent uncertainty in the critical heat flux; (2) Pool studies: heat transfer inside of horizontal, open ended heated tubes immersed in a pool; (3) Pool studies: natural-convection burnout of closed vertical channels; (4) Forced-convection investigations; subcooled boiling and burnout with heated twisted tapes; and (5) Forced-convection investigations; swirl-flow forced-convection bulk-boiling loop.

The subject which I will discuss is the distorted - waves theory of direct reactions and its application to the study of nuclei. I shall mainly be concerned with a study of the reaction theory, its range of validity, and its ability to give quantitative information about nuclear structure.

A replica electron microscope study of as-polished and cathodically etched surfaces of pyrolytic carbon coating on fuel particles has been made in an attempt to characterize coatings that showed as much as a 30% difference in bult density. High and low density coating could be characterized by their polished surface textures; however, these features were not indicative of the true structure as seen by direct electron transmission. Microvoids detected by the transmission study of cleavage flakes exist on too fine a scale to be observed either optically or by electron microscope examination of replicas of the polished surface. Other features such as the effect of cathodic and chemical etching, coating delamination, and duplex coating interfaces have also been examined.

The series of papers that we are about to discuss is primarily concerned, not as the first part of the session title indicates, with photochemistry of nucleic acids, but, as the second part indicates, with the biological implications of the photochemistry. We know that ultraviolet acts on nucleic acids in cells, and we know a good deal about the photochemistry of this interaction in vitro. The question we ask here is, which test tube reactions are of importance to the survival of the cell?

The quasi reference electrode ( Q.R.E. ) is a bright platinum wire or other inert conductor immersed directly in the solution; it may have a very small area. It is used instead of a true reference electrode but must be used with potentiostatic or other circuits that prevent the drawing of cell current through the Q.R. E. When used in appropriate situations, the results obtained by use of a Q.R.E. are like those obtained with a true reference electrode except for the lack of thermodynamic meaning of the Q.R.E. potential ; hence , this simple electrode is called a quasi reference electrode.

From the questions which have been asked, I gather that I am expected to bring you the news of the latest exciting developments in desalination at the Oak Ridge National Laboratory. However, the agenda for this meeting does not include reports of unfinished investigations; moreover, although there are some new ideas afoot at Oak Ridge, they are aimed toward the very large stations which are somewhat beyond the scope of the more current interests represented here. So instead of presenting new developments, I would like today to talk about where to look for them--to give you some purely analytical considerations that assess the incentives we have to seed certain improvements in this or that portion of the equipment in a dual-purpose station.

This semiannual progress report and future reports will be published as two documents to permit a wider distribution of the unclassified material. The report numbers are assigned in sequence so that the two reports will fall together when filed by report number.

The first step in a proposed processing method for recovery of uranium from graphite-uranium fuels consists of oxidation of the fuel by oxygen to volatilize the carbon. Residue ash from the combustion step can be treated in a variety of ways to recover and purify the uranium. The combustion step may be caried out by contacting the solid fuel in a fixed or moving bed with a stream of oxygen-bearing gas in a tubular or annular reactor. Oxidizing gas may be introduced to the reactor at several points up the reactor and there may be continuous or intermittent addition of fresh fuel and removal of residue ash.

The thermophysical properties of Armco iron such as thermal conductivity, electrical resistivity, and Seebeck coefficient have been extensively investigated and reviewed up to 1000 degrees C. Few investigations of such properties have been made on high purity iron. If such a study is made using the same apparatus to determine the properties of two purity levels of iron, then several significant intercomparisons can be made which add meaning to data on a single material. The systemic errors for a single apparatus are the same, therefore comparison of a property of two similar materials is more significant. A comparison of the property changes with temperature and purity can show the effects of impurities on the mechanisms contributing to a property and allows prediction of the properties of iron as a function of purity. For these reasons a study was initiated on the high-purity iron for comparison to Armco iron.

The experimental details, mathematical models, and typical data for a rapid comparative method for thermal conductivity measurements are presented. The method consists of measuring the temperature change of a small silver sphere after it is brought in contact with a small disk-shaped specimen which was initially at ta higher temperature. This temperature change was calibrated in the range of 50 to 400 degrees C by making measurements on samples of know thermal conductivity. The accuracy of this technique was shown to be between than +-10% with a reproducibility of at least +-2.5%. Using known transport mechanisms for heat conduction in solids and the temperature dependency of the electrical conductivity, a means to judiciously extrapolate thermal conductivity data obtained between 50 and 400 degree C to high temperature is presented.

Grade CGB graphite is a nuclear graphite which is basically an extruded petroleum coke bonded with coal tar pitch. No carbon blacks are used and the low-permeation graphite is finished through a series of impregnations and heat treatments with a final heat treatment of all components to 2800 degrees C. A listing of the results obtained is given in Table 1. The results at 51 degrees C are considered questionable. There was a slight contamination of the 90% Pt 10% Rh-Pt thermocouples at 910 degrees C but it was not sufficient to doubt the validity of the 910 degrees C results. However, the results obtained at 1015 degrees C should be disregarded because of severe thermocouple instabilities. In addition, the electrical resistance of the core heater at 603 degrees C indicated the thermocouples had a -10 to -15 degree error which is sufficient justification to disregard the 605 degrees C data.

The first man-made nuclear reactor -- or "pile" as it was then called -- was rather hurriedly improvised and operated in a crowded space under the athletic bleachers of Stagg Field at the University of Chicago on December 2, 1942. Just prior to this time, there began the assembly of a group of physicists with an unusual assignment. They were determined that radiation hazards of unprecedented proportions must be coped with successfully in the conduct of reactor programs as planned. Since these physicists were to be concerned with the health of radiation workers, they were called health physicists. There was no formal instruction available to this first group of health physicists and they perforce received training as they felt their way by firsthand experience and by trial and error. Health physics at Oak Ridge National Laboratory from the very beginning has been organized into three principal areas: applied activities, education and training and research.

The calculation of concentration transients caused by mixing in the interconnected three-body system of the fuel dump tanks, core and blanket has been coded for the IBM-704. The system of equations includes material balances, the dependence of critical temperature on core and blanket concentrations, and the effect of temperature (density) changes on flow rates. The controllable flow rates, the fuel dump tank weight and the initial conditions are input variables. Outputs include core and blanket concentrations, critical temperature, concentration ratio and power ratio. The code has been used to compute transients during a number of operating situations.