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The normalized $^{238}$U(n,f)/$^{235}$U(n,f) cross section ratio has been measured using the NIFFTE fission Time Projection Chamber from the reaction threshold to $30$~MeV. The fissionTPC is a two-volume MICROMEGAS time projection chamber that allows for full three-dimensional reconstruction of fission-fragment ionization profiles from neutron-induced fission. The measurement was performed at the Los Alamos Neutron Science Center, where the neutron energy is determined from neutron time-of-flight. The $^{238}$U(n,f)/$^{235}$U(n,f) ratio reported here is the first cross section measurement made with the fissionTPC, and will provide new experimental data for evaluation of the $^{238}$U(n,f) cross section, an important standard used in neutron-flux measurements. Use of a development target in this work prevented the determination of an absolute normalization, to be addressed in future measurements. Instead, the measured cross section ratio has been normalized to ENDF/B-VIII.$\beta$5 at 14.5 MeV.

The Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) collaboration is developing a Time Projection Chamber (TPC) to measure neutron-induced fission cross sections with unprecedented accuracy. Modifying TPC technology for nuclear physics applications is a challenging endeavor, and frequent testing and evaluation is required to ensure that all components are behaving as expected. In-beam tests of the NIFFTE TPC at the Los Alamos Neutron Science Center (LAN-SCE) commenced in 2010. An overview of the NIFFTE TPC experiments performed at LANSCE will be presented, along with preliminary performance results.

A fission TPC is being developed to measure the energy-dependent neutron induced fission cross sections of the major and minor actinides to an accuracy of better than 1%. Achieving such an accuracy will depend in part, on the ability of the TPC to provide precise tracking and identification of charged particles. A measurement of the α -decay to spontaneous fission branching ratio of 252 Cf used to benchmark the performance of the TPC will be discussed.

The NIFFTE collaboration has developed a time projection chamber to study neutron-induced fission events in actinide targets by tracking and identifying fission fragments in three dimensions as they traverse a gas volume. This paper will provide an overview of the analysis software that has been developed by the NIFFTE collaboration, as well as examples of its success in analyzing data.

When fully instrumented, the NIFFTE Time Projection Chamber will consist of nearly 6000 channels, each of which requires a preamplifier, ADC, and digital readout. To minimize channel cost and size, the EtherDAQ data acquisition system utilizes off-the-shelf FPGA and Ethernet fiber technology. This application of commercially-available components made it possible to meet the requirements of the DAQ system with considerably less development cost and time than the a customized ASIC solution, and provides considerable flexibility in the final design. The detailed design and current status of the preamplifier and EtherDAQ boards will be discussed.

The general properties needed in targets (sources) for high precision, high accuracy measurements are reviewed. The application of these principles to the problem of developing targets for the Fission TPC is described. Longer term issues, such as the availability of actinide materials, improved knowledge of energy losses and straggling and the stability of targets during irradiation are also discussed.

The Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) is a double-sided Time Projection Chamber (TPC) with micromegas readout designed to measure the energy-dependent neutron-induced fission cross sections of the major and minor actinides with unprecedented accuracy. The NIFFTE project addresses the challenge of minimizing major sources of systematic uncertainties from previous fission chamber measurements such as: target and beam non-uniformities, misidentification of alpha and light charged particles as fission fragments, and uncertainties inherent to the reference standards used. In-beam tests of the NIFFTE TPC at the Los Alamos Neutron Science Center (LANSCE) started in 2010 and have continued in 2011, 2012 and 2013. An overview of the NIFFTE TPC status and performance at LANSCE will be presented., Comment: Prepared for JINST as proceeding of the MPGD13 Conference

A measure of empowerment was developed and its psychometric properties evaluated. Employees (n = 52) of two hospitals participated in semistructured interviews and a pilot test of the research instrument. A second study was undertaken with professional, support, and administrative staff (n = 405) of four community hospitals. Psychometric evaluation included factor analysis, reliability estimation, and validity assessment. Subjects responded to questionnaires measuring empowerment, leadership behavior, organizational citizenship behavior and job behaviors related to quality improvement. Factor analysis indicated three dimensions of empowerment: behavioral, verbal, and outcome empowerment. Coefficient alphas ranged from .83 to .87. The three dimensions were positively related to leadership behavior that encouraged self-leadership and negatively related to directive leadership. The three dimensions discriminated between the empowerment level of managers compared to that of nonmanagement staff. Empowerment predicted organizational citizenship behavior and job behaviors related to quality improvement.

The distribution and dendritic morphology of neurons in the cat pretectal nuclear complex were analyzed with respect to their projection to the ipsilateral dorsal lateral geniculate nucleus (LGNd) and the ipsilateral inferior olive (IO). Single and double retrograde tracing techniques were combined with intracellular injections of either horseradish peroxidase into electrophysiologically identified pretectal neurons or Lucifer Yellow into retrogradely labeled somata. Pretectal cells afferent to the LGNd were located in the nucleus of the optic tract (NOT), adjacent dorsal terminal nucleus of the accessory optic system (DTN), and posterior pretectal nucleus (NPP). Cells projecting to the IO were also distributed throughout the NOT-DTN and dorsal part of the NPP. Separate tracer injections (fluorogold and horseradish peroxidase [HRP] or granular blue) into the LGNd and the IO showed considerable overlap of labeled neurons in the NOT and dorsal NPP. Double-labeled neurons, however, were not observed after double tracer injections into LGNd and IO. Partial topographical segregation of the two populations was observed along the dorsoventral axis because LGNd-projecting neurons exhibited maximum density ventral to that of IO neurons. Pretectal cells to the LGNd had cell body diameters between 16 and 48 microns. Somatic shapes varied between fusiform and multipolar with considerable overlap between these two morphological appearances. Neurons projecting to the IO exhibited similar cell body sizes and their morphology also varied from fusiform to multipolar. Quantitative analysis of dendritic field size and orientation, number and order of dendritic arborizations, and symmetry of the dendritic tree revealed no statistically significant difference between the two neuronal populations. Hence, neurons of the two populations cannot be unequivocally identified just from the dendritic morphology. By contrast, dendritic morphology was correlated with the topographical location of either cell type within the pretectal nuclei rather than projection. Thus, the morphological appearance of neurons located dorsally predominantly was fusiform while neurons located ventrally mostly were multipolar.

This paper describes an experiment designed to compare the readability of normal English orthography with that of text produced by a Palantype transcription system designed as an aid for the severely and profoundly deaf. The Palantype transcription system has been described in detail in an earlier paper in this Journal. To provide guidance for future development work, two artificially produced enhancements of the transcription system are also compared with the normal transcription system output and with English orthography. The experimental subjects are members of local deaf and hard of hearing clubs. The experiment is based upon the Cloze technique: words are deleted from the original text and subjects are asked to replace these missing words. Standard texts, normally used for measuring reading ability, form the experimental material. The experiment uses a modiffed Latin squares design. Statistical analysis of the results shows that there are significant differences between the different text treatments, and some attempt is made to quantify these differences in terms of measures of reading ability commonly used in the educational field.

The increasing availability of microcomputers and video technology in schools is opening the way towards local ‘do-it-yourself’ video subtitling facilities. Over the last five years, many teachers of deaf children have begun to recognize the educational benefits of subtitled television, but the means for effective, yet low-cost, subtitling did not exist. Building on our earlier experience with broadcast-teletext subtitling we initiated work, funded by the Mountbatten Memorial Trust, to fulfil this need. To gauge the extent of interest in local subtitling, and to gather design data for the project, a national survey of the uses of television and related media in the education of deaf children was undertaken. Existing methods of adapting educational broadcasts to provide access for deaf children were of particular interest in the survey. As a result of our work, a prototype low-cost subtitling system has been developed, based on video and computer equipment already widely available in s...

A technique is described for producing sterile cultures of young leafy (‘primary’) shoots of Sphagnum cuspidatum from surface-sterilized spores on mineral agar. When these were transferred to sterile aqueous mineral nutrient solution contained in Erlenmeyer flasks, growth was slight and abnormal. Plants resembling those that occur naturally could be produced only when air enriched with carbon dioxide was passed through the solution. The branches produced on these ‘first generation’ plants all resembled innovations (i.e. were of unlimited growth and. terminated in capitula). Second generation plants were obtained by removing the capitula from plants of the first generation and replacing them in aqueous culture solution and third generation plants by repeating the procedure on those of the second generation. Almost all of the branches on the third generations resembled fascicular branches (i.e. were of limited growth and lacked lateral branches and capitula). Plants of the second generation all prod...

The provision of television captions for the benefit of the hearing impaired is the growing practice of many broadcasting organisations. This paper discusses the research and design work which led to the development of 'NEWFOR', a caption preparation system for broadcast teletext. Caption preparation is a complex and time-consuming task, which often required as long as 30-40 hours preparation time per captioned programme hour using early teletext origination systems. Research carried out into the display requirements for captioning for the hearing impaired led to a design specification for a stand alone caption preparation system and a handbook of guidelines on captioning. Analysis of the operational requirements of caption preparation provided a framework for optimal task division between the human captioner and the captioning computer. The system developed as a result halves caption preparation time, and also permits captioning of live programmes. The system described is now available commercially and is used for all teletext captioning by Independent Television in the UK.

The potential economic and technological advantages of welding over other joining techniques have made it the principal fabrication process for a wide range of engineering products. However, the achievement of good weldability makes demands on material quality which the material supplier must optimize with the required mechanical behaviour and an acceptable cost. The physical metallurgist has contributed significantly m providing a sound basis for materials selection based on an understanding of the potential welding problems and the factors responsible for them. The principal welding problems in steels, nickel alloys, aluminium alloys and titanium alloys are briefly outlined and the influence on material specifications discussed.

During the growth of coherent precipitates stresses are generated because the lattice dimensions of the precipitate differ from those of the matrix. Whon the strain energy is large enough it will be relieved by the precipitate losing continuity with the matrix, i.e. becoming non-coherent. It is suggested that this will occur by the formation or annihilation of close-packed planes of atoms by the aggregation of either interstitials or vacancies. This leads to the formation of dislocations at the interface. The exact nature of the process in a given precipitate will depend upon both the shear stresses and hydrostatic stresses acting on the close-packed planes and upon the stacking-fault energy of the precipitate. The problem is given a general treatment for the case of precipitation in a f.c.c. matrix.

The photoneutron cross sections of the 50-neutron isotopes Rb87, Zr90, and Mo92 have been measured as a function of photon energy. These cross sections exhibit the peaked shape characteristic of photonuclear reactions. Peak values of 0.23, 0.27, and 0.14 barn at 17.5, 18.0, and 18.7 Mev. respectively were found for these nuclei. The widths of all the curves at half maximum were about 6 Mev. In the case of zirconium and molybdenum the cross sections to the isomeric and ground states of the residual nuclei have been determined separately. The ratio of the cross sections, σ ground/σ isomeric, has been examined as a function of photon energy and is discussed in the light of the elementary analysis previously presented.

The angular distributions and the yields of the high-energy neutrons emitted in photodisintegration have been studied by silicon detectors (25 elements) and aluminum detectors (6 elements). With the silicon detectors systematic variations are apparent in the coefficient a2 of W(θ) = a0(P0 + a2P2), and these variations are interpreted in terms of the Wilkinson shell model of photonuclear reactions.

In this paper, an empirical method is developed for determining magnitude of seismic events from the amplitude of Lg phases recorded at local to regional distances from the events. The data used were obtained from Long Range Seismic Measurements (LRSM) reports for 78 seismic events associated with explosions conducted the Atomic Energy Commission. Preliminary investigation showed that magnitudes (M) calculated from Lg recordings had less scatter than body-wave magnitudes (m) reported for the same events and stations. A sixth-degree polynomial was found to give the best fit to log amplitude/period (A/T) values plotted as a function of epicentral distance. Amplitude-distance correction factors (Q) are presented in a chart. Magnitudes from Lg were compared to the average unified magnitudes from LRSM shot reports. For 60 of 68 events, the standard deviation for M was less than that for m. The M values for all of the events were normalized to magnitude 5.0, and average residuals were found for 69 reporting stations. A plot of the residuals on a map indicates that they represent station corrections rather than azimuthal variations. Apparent station corrections (s) are presented for 23 LRSM stations.

THE APPLICATION OF PROTECTIVE COATINGS TO WELDED STRUCTURES IS DESCRIBED. THE ECONOMIC AND MAINTENANCE PROBLEMS INVOLVED, THE WELDING OF HOLLOW MEMBERS, STRESS CORROSION CRACKING AND LIMITED LIFE DESIGN, AND CORROSION FATIGUE ARE DISCUSSED. THE POINTS MADE ARE ILLUSTRATED BY SOME EXPERIMENTAL RESULTS. /AUTHOR/

If electronic progress follows the pattern set after World War I, the next decade will see the expansion of techniques nurtured by military need: frequency modulation, television, facsimile, and radar. Economic considerations, however, probably will set the rate and limit of their expansion.

A technique is discussed for the possible use of the Lg phase for magnitude determination for regional and near regional events. Data used in this study was obtained from several test shots at the Nevada Test Site recorded by Long Range Seismic Measurements stations. The comparison of magnitudes determined by this method appear to give better results for epicentral distances up to about 2000 km than the body wave technique presently in use. This research is the result of a preliminary investigation to determine the feasibility of the method and further study is continuing.

The purpose of this paper is to explain very briefly how welding may lead to corrosion problems in structural engineering. A table is given summarising corrosion problems in welded joints of various materials possible causes of these problems and their remedies.

131I incorporation in spontaneous mammary tumours and other organs of C3H mice has been examined as a function of time following the administration of 131I UDR. After a period of four days, the tumours were labelled with higher specific activity than any other tissue. The absolute amount of incorporation was increased by pretreatment with FUDR and by subcutaneous rather than intraperitoneal injection. CDR administered with the IUDR did not increase incorporation. A possible explanation for these findings has been given. The results of the study were sufficiently encouraging to justify a clinical trial of 131I UDR in the localisation of human tumours with our whole body scanner.

When plant introductions of 14 vetch ( Vicia ) species were tested for resistance to Bruchus brachialis Fahraeus, V. angustifolia L., V. ervilia Willd., V. hirsula S. F. Gray, V. lulea L., V. monantha Retz., V. peregrina L., and V. sativa L. were classified as resistant. Those classified as susceptible were: V. cracea L., F. dasycarpa Ten., and V. villosa Roth. Also, results with 7 introductions of V. benghalensis L. indicated that this spceies is segregating for resistance to the vetch bruchid. Nonpreference for oviposition appeared to be the major mechanism contributing to resistance.

In most radiotherapy centres the required exposure dose for a prescribed absorbed dose at the site of interest is first determined and then, from the exposure dose-rate, the treatment time is calculated. Thus, the radiographer is required to calculate the treatment time for each given dose, set this time on the timer and turn on the machine. We have developed a device, which is being put on all our X-ray and isotope machines, which circumvents the necessity for calculating the time of treatment. The radiographer sets a counter to the prescribed dose, turns a knob to select one of four techniques, sets an indicator to the field size and turns on the machine. The machine shuts off when the proper time has elapsed. In addition, a simple scale allows for adjustment to take into account the decay of the source, or the change in exposure rate from the X-ray machine. The device is represented schematically in Fig. 1. The heart of the device consists of two hardened, tapered rollers which are coupled together wit...

Results of management of a closed series of primary bladder carcinoma over a 20-year period by a multidisciplinary team are presented. Patients were classified by the TNM method before treatment. These experiences indicate that stage and grade are relevant to prognosis and treatment. The TNM classification can be precise and practical when used diligently by a treatment team. Although no new methods of treatment are offered, the treatment now available may be utilized to better effect if programmed to allow care of the patients by a team, especially if the team explores the limits of radiation and surgery in their hands.

Pacemaker rate responsiveness derived from changing central venous blood temperature requires the development of sensor leads that are stable and reliable. The relevant characteristics of one such design are described. Temperature response time, data acquisition time, temperature sensitivity, and long-term sensor shunt impedance have been studied both in vitro and in vivo. These parameters are analyzed with respect to the intrinsic temperature signal and to pacemaker implementation problems.

The dynamic impact tests at Southwest Research Institute for the first time exposed human volunteers to production-like driver air cushion system depolyments at impact levels equivalent to a 30 mph barrier crash (48 kph). No significant injury was produced. At no time was it necessary for the secondary restraint systems to be utilized and the entire program schedule was carried out as planned. All tests were conducted under the most safe and controlled conditions possible, and typify only what the air cushions might accomplish in direct, head-on impacts up to 30 mph (48 kph). In comparing the test results, the anthropomorphic dummies' response to impact was conservative compared to the human volunteers. These and other human volunteer tests were run to help understand what might be expected in real world driving conditions. To further understand the value of this new safety system, 1000 1973 Chevrolets were built and places in a high mileage fleet across the couhtry. They now have accumulated 41 millions miles of experience and have had 15 accidents of sufficient severity that the air cushion depolyed. This fleet was followed with 1974 vehicles with air cushions sold to the general public as an option. These cars, combined with the test fleet, have accumulated approximately 60 million miles and have a total of 25 depolyments with 34 occupants in the front seat. There has been one fatality in accidents involving these vehicles, a seven week old baby boy. The child was not restrained in any protective carrier. All other injuries have been classified AIS-1 except for three AIS-2. Facial injuries have been very minimal and there have been no known hearing impairments as a result of these accident situations. To date, the results have been encouraging but caution must be taken in their interpretation. The population of drivers is not to be considered normal. The 60 million miles may appear to be a large number, but only represents 25 minutes of driving time of the total U.S. car population in 1 year.

During the fall of 1980 a geomorphic investigation was conducted in the Brushy Creek area, of Webster County, Iowa, as part of the assessment of cultural resources in the area. This investigation (by E. A. Bettis III) made note of several exposures in stream cut banks which revealed some unique Quaternary stratigraphic sections. These sections were described preliminarily by Bettis. During the summer of 1981 the authors revisted these locations to describe the stratigraphy in detail, and also to obtain samples to analyze the particle-size distribution and mineralogy of the sediments for characterization and correlation, to analyze the paleontological remains in selected samples, and to obtain further samples for radiocarbon dating from these sections. Selected samples were processed for pollen using techniques modified from Faegri and Iversen (1975) as outlined in Hallberg, Baker, and Legg (1980). Bulk samples were also screened and hand-picked for plant macrofossils and insect remains. The deep valley of Brushy Creek exhibits many terraces, as shown in figure 1. The terraces range in estimated age from late Holocene (T-1) through middle to early Holocene (T2, 3, and 4) to early Holocene (B). These are discussed in detail elsewhere by Bettis (1980). Figure 1 also shows the location of the two sections described in this report, 94 BCA and 94 BMH.

This paper describes a survey into the use of television and related visual media in the education of hearing-impaired children in the UK. The main purpose of the survey was to furnish background information for the development of a low-cost video subtitling system for use in special schools and in units for hearing-impaired children in ordinary schools. An effective method of reducing cost is to base the system on equipment that schools and units already have. The survey indicates that domestic-type video recorders are becoming almost universal. Suitable microcomputers for running subtitling software are also widespread. Other results of the survey reveal: (i) widespread and fairly heavy usage of schools television programmes; (ii) the need for various visual aids and for considerable effort on the part of teachers in making the programmes accessible to hearing-impaired children; (iii) a significant demand for subtitling equipment; (iv) higher incidence of more sophisticated television equipment (video cameras, teletext receivers) and of human technical support in special schools than in hearing-impaired units.

A theoretical approach to the design of an optimum gamma camera system has been made by a mathematical formulation describing the operation of the system. The parameters considered as variables were the light guide thickness, the geometric array of photodetectors, the photocathode diameter, the phototube gain and the signal fractions inserted into the signal mixing network. Parameters which optimize the performance relative to transfer efficiency, image linearity and spatial resolution were determined. It was found that an optimum light guide thickness is approximately equal to one-half the tube separation distance (i.e. the radius of the detector phototube for the close-packed case). Peripheral tubes in the array must have increased gains relative to those in the centre. The optimum signal fractions agree well with those obtained by others using an empirical approach. The spatial resolution estimates are not widely different from those observed in systems already developed. This analysis indicates that the empirically developed systems now in routine use are near optimal and no dramatic improvements may be expected from further developments using presently available components.

Various kinds of scans were performed on 439 patients, using several types of radioactive substances. Using I(131), functioning metastases were demonstrated in 11 of 26 patients with follicular or papillary thyroid cancer; in three of these patients the results of scans were a decisive influence in attempting radioiodine therapy. Radioiron scans demonstrated extramedullary hematopoiesis in patients with polycythemia vera, myelofibrosis, and myelophthisic anemia. Radiocopper studies showed abnormal concentration in the kidneys in two patients with Wilson's disease. Radioactive strontium localized in bone metastases in at least four patients with malignant disease. Liver and kidney scans, using I(131)-Rose Bengal and Hg(203)-Neohydrin respectively, have been useful in the management of patients suffering from malignant disease, renal hypertension, and certain other disorders.