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An effective mass stress Hamiltonian for the Γ8 ( j = 3/2) valence bands in germanium has been used to calculate the Landau levels in p-germanium. The magnetic fields and the stress have both been taken in the [100] direction. The stress induced changes in the band structure are related to experimentally observed shifts in the de Haas-Shubnikov longitudinal magneto-resistance oscillations. Un Hamiltonien de masse effective qui rend compte de pression uniaxiale a ete utilise pour calculer les niveaux de Landau dans les Γ8 ( j = 3/2) bandes de valence de p-germanium. Les champs magnetiques et la pression sont dans la direction [100]. La structure des bandes change sous pression et il y a une correlation avec les oscillations expermentales de Shub-nikov-de Haas pour la magnetoresistance longitudinale qui subissent des deplacements relatifs sous pression uniaxiale.

The heave, pitch, and roll equations of motion for an Air Cushion Vehicle are derived. The dynamic response to a random seaway is predicted from the linearized perturbation equations and compared with experimental tests of a subscale dynamically similar model operating in a towing tank. Frequency domain seakeeping analysis to determine acceleration response, frequency of bow slamming, structural loads, and relative motion between two craft is demonstrated. Because the atmosphere is not scaled during subscale model tests, an appreciable dynamic distortion is reflected in lift system physical parameters. This scaling problem is discussed and avenues of further subscale model experimental research are suggested.

PULLORUM disease has been recognized as one of the most costly diseases of poultry. The National Poultry Improvement Plan has as one of its main objectives the eradication of this disease. One of the most common means of transmitting the disease is through the egg. The control measures at present consist of blood testing the breeding flocks, hatchery sanitation, and good management practices. Blood testing of breeding flocks is time consuming and costly. The breeders reacting to the test are sold for meat at a loss to the producer. While the blood test is the best control measure, it is not 100 percent effective. Outbreaks of the disease may occur in flocks previously found to be negative. Repeated tests are necessary to control the infection. Sulfamerazine and sulfadiazine have been found effective in the control of pullorum disease in chicks. Severens, Roberts and Card (1945) report that sulfamerazine (0.5 percent) . . .

PULLORUM disease is of great economic importance to the poultryman. Much progress has been made in the control and eradication of this disease by means of the blood test; however, outbreaks of the disease still occur indicating that the materials used in testing and/or testing methods must be improved. In order to aid the poultryman where acute outbreaks of pullorum disease occur various sulfonamides which may be of benefit have been investigated. Severens, Roberts and Card (1945) found that 0.5 percent sulfamerazine or 2 percent sulfadiazine protected a high percentage of chicks exposed to artificial inoculation of Salmonella pullorum. Mullen (1946) reported that 0.5 percent sulfamerazine in the feed reduced the mortality in turkey poults naturally infected with S. pullorum. Anderson (1946) reported that 0.5 percent sulfamerazine in the feed reduced the mortality in chicks that were naturally infected with S. pullorum. Mattis, et al. (1946) found that no significant . . .

1. Four varieties of marrow stem kale, three of thousand headed kales, Hungry Gap Kale and Rape-Kale were grown at three centres in mid-Wales. They were sampled in the early winter period and separate leaf and stem samples analysed for the proximate constituents and minerals.2. Leaf to stem ratios were measured on both a green and dry matter basis and the latter values used to calculate whole plant values for the chemical constituents.3. The leaves of the marrow stem kales were higher in dry matter than the stems, except in the case of the Purple Stem Kale. This variety resembled the thousand headed and rape-type kales in having a higher dry matter in the stems. On a dry matter basis, the leaves of all the varieties were richer than the stems in ether extract, crude protein, total ash and all the minerals except potassium and sodium. These elements occurred to a greater extent in the stems of the fleshy stemmed marrow stem kales than in the leaves. The stems were higher in crude fibre and nitrogen-free extractives.4. The leaves of the rape-type kales were higher than those of the other varieties in silica, phosphorus and potassium. They were the best source of phosphorus on a whole plant basis. The marrow stem kales had considerably higher leaf and stem values for sodium and were markedly superior to the other varieties as a source of the element.

The Percus–Yevick and hypernetted chain theories are used to investigate the sensitivity of the pair potential [Formula: see text] to errors in the measured structure factor S(K) for several liquid metals and nonmetals. The linear relation between small errors, [Formula: see text], is studied by means of a generalized eigenvector analysis. Only those combinations of errors in S(K) which correspond to large eigenvalues lead to significant uncertainties in [Formula: see text]. The general form of the dominant eigenvectors was found to be the same for all liquids studied, except near the critical point. With this same exception, the following conclusions hold: Errors in S(K) for small K have by far the greatest effect on [Formula: see text]; the depth of the attractive portion of [Formula: see text] is most sensitive to errors in S(K); the repulsive core of [Formula: see text] is insensitive to errors in S(K); and the height of the main peak of S(K) has very little effect on [Formula: see text].

1. Five varieties of thousand-headed kale, grown in singled and unsingled plots, were sampled three times during the winter at monthly intervals. The plants were divided into leaf, top half of the stem and bottom half. Dry matter, the proximate constituents and minerals were determined in the samples.2. The differences in the composition of the leaf and stem of the plant were similar to those found previously and the top half of the stem was intermediate in composition between the leaf and the bottom half of the stem for all the constituents except potassium.3. The proportions of the various constituents occurring in the three portions of the plant were calculated and considered in terms of the incomplete utilization of the crop by grazing animals.4. There were significant increases in the percentage of dry matter in all three portions of the plant as the season advanced. The only other significant changes in composition with advancing season were in the leaf in which the levels of crude protein, crude fibre, ash, calcium, phosphorus and sulphate varied.5. Singling the crop had no significant effects on its composition, but there was a tendency for the stems of the singled crop to be lower in crude fibre and higher in crude protein and several of the minerals.6. There were very few differences in the composition of the varieties. They were mainly due to the higher mineral levels in one variety.7. Samples of the two halves of the stem of thousand-headed kale were divided into their main tissues, e.g. rind, xylem and marrow. These were analysed in the same manner as the samples in the main investigation. The results were used in an attempt to explain the effects of singling, advancing season and variety in terms of different ratios of these tissues.

1. Four varieties of marrow stem kale in the first season, and thirteen in the second, were sampled on three occasions during the first half of the winter. Intervals between samplings were up to 1 month. The plants in the samples were divided into leaf, top half of the stem, and bottom half. The levels of dry matter, proximate constituents and minerals were determined in each sample.2. The differences in composition between the three main fractions of the plant were highly significant for all the chemical constituents, except magnesium. The values for the chemical constituents in the top half of the stem were intermediate between those of the leaf and the bottom half of the stem for most constituents; it had the lowest values for dry matter and the highest for potassium and phosphorus. The distribution of chemical constituents between the whole stem and the leaf were similar to those reported previously.

1. The effects of annual applications of 0–12 cwt. per acre of sulphate of ammonia on the herbage levels and yields of sulphate sulphur and total sulphur were investigated in four seeds mixtures 1 year and 4 years after seeding down.2. There were significant increases in the levels and yields of both forms of sulphur up to the 2 or 4 cwt. per acre level of application in both years. The maximum values occurred at the 6 or 8 cwt. level and the corresponding values at the 12 cwt. per acre rate of application declined in many cases.3. The cumulative effects of the annual dressings of sulphate of ammonia resulted in substantial increases of approximately 50% in the levels of sulphate sulphur and total sulphur with much smaller increases in the levels of non-sulphate sulphur.4. Duplicate plots which received 2, 4 and 6 cwt. per acre of sulphate of ammonia also received an additional 2 cwt. per acre immediately after the first cut each year. This splitting of the dressings had no significant effect on the accumulation of sulphur by any seeds mixture. A second cut from the cocksfoot plots in the first year showed the sulphur levels in the plots which received the additional sulphate of ammonia to have increased less than the levels in those which received only the initial dressing. This was explained in terms of the yields of the components.5. There was a tendency for the rye-grass mixture to contain more sulphate than the other mixtures particularly in the fourth year.6. The possible significance of the increases found in sulphate levels in the copper-molybdenum metabolism of grazing animals is discussed.

The hazards involved in the handling of naked radium in the radium dial painting industry are surveyed. The suggested tolerance values of 0·1 microgramme of radium in the body (or alternately 10−12 curie/litre in the expired air) and 10−10 curie/litre of radon in the atmospheric air of workrooms are discussed and results given of measurements on workers and workrooms in the industry.

Information can now be read in the form of an extended spatial distribution of charge. The technique involved shows considerable promise for use in spectrometry.

1. Three varieties of giant rape, two broad leaved Essex rapes, Hungry Gap Kale and Rape-Kale, were grown at two centres in mid-Wales. They were sampled in the early winter period and the samples divided into separate leaf and stem samples. These samples were used to calculate leaf to stem ratios on a green and dry-matter basis.2. The levels of the proximate constituents, silica, calcium, magnesium, phosphorus, sodium, potassium, chlorine, total sulphur, sulphate sulphur and ‘organic’ sulphur were determined in the dried samples. Whole plant values were calculated from the leaf and stem values with the appropriate leaf to stem ratios.3. The leaf values for ether extract, crude protein, silica-free ash, silica, calcium, phosphorus, magnesium, chlorine, total sulphur and ‘organic’ sulphur are higher than the corresponding stem values. For dry matter, crude fibre, nitrogen-free extractives and sodium the reverse is found, whilst for sulphate sulphur there is no definite distribution.4. There are no significant differences in composition between the main groups of varieties, and the rape-type kales are very similar to the other rapes in this respect.

The planning of treatment for patients with gynaecological cancer undergoing combined intracavitary and external beam irradiation at the Royal Marsden Hospital is described. The purpose of the external beam irradiation is to increase the dose to the parametria and pelvic nodes since these tissues are generally too far from the intracavitary 137Cs sources to receive a tumoricidal dose. The treatment policy and problems of dosimetry are discussed. The main problem is to combine the two modes of radiotherapy so as to ensure an adequate dose to the required regions and to afford protection to previously irradiated areas. The method of computing the dose distribution from the intracavitary 137Cs sources is described and also how this distribution is used to design protective absorbers for use with the external beam therapy. Different shapes of absorbers are required for cobalt units and linear accelerators because of the different beam characteristics. The way in which these are designed for individua...

1. Four varieties of marrow stem kale, three of thousand headed kale, Hungry Gap Kale, Rape-Kale and five other rape varieties were sampled at two centres in mid-Wales and separate leaf and stem samples analysed for manganese, molybdenum and boron. Similar samples of four varieties of marrow stem kale, two of thousand headed kale, Hungry Gap Kale, Rape-Kale and two other varieties of rape were taken from two further centres and prepared with the most stringent precautions to prevent contamination. Iron, copper, zinc and lead were determined in these samples.

The photon flux spectra from two 6 MeV Linear Accelerators and a 2 MeV Van de Graaff Generator which are in normal use for radiotherapy, have been measured using a 7·5 × 7·5 cm NaI (Tl) crystal spectrometer. The X-ray beam was scattered by aluminium sheets to reduce the intensity and energy range, and the primary spectra calculated from the measured scattered spectra using the Klein-Nishina formula. The crystal spectrometer was calibrated from theoretical Monte Carlo calculations which were compared with experimentally obtained isotope spectra. The measured pulse height spectra were converted to photon flux spectra by a digital computer. Photon flux spectra were obtained for different field sizes and under different operating conditions, and the variation in the spectra over the X-ray field was investigated. The results were compared with theoretically calculated thick target spectra using published formulae for the bremsstrahlung cross-sections.

The use of radioactive yttrium (90Y) is reviewed as an alternative to 198Au for malignant effusions. Fifteen cases were treated by intracavitary injection of a new compound, colloidal yttrium silicate. Of nine patients surviving longer than one month, six received good palliation for periods ranging from five to 19 months. The intracavitary retention and extracavitary dosage are detailed and compared with those of other yttrium preparations and with gold.

Injections of 150–200 mc of colloidal radioactive gold into the intraperitoneal space and 75–100 mc intrapleurally have been found from clinical experience to be of considerable radiotherapeutic value. It is of importance to consider how far this experience in the millicurie injection required can be transferred to similar treatments with other isotopes, and in particular to the use of colloidal 90Y considered in Section I of this paper. A calculation of the probable doses given, in terms of rads, for some of the various conditions that may occur in practice may provide some contribution to the further development of this type of treatment. The integral dose delivered can readily be calculated from the half-lives of the isotope and the average β energy, but the actual dose delivered to individual tissues will depend as well on the volume of fluid in the cavity and the depth below the surface of the point considered. This variation will generally be different for different isotopes. Doses to the peritoneal...

Semi-empirical local and nonlocal pseudopotentials have been used to calculate the energy bands and Fermi surface of crystalline mercury. The nonlocal pseudopotentials were an approximation in which the repulsive potentials of the outer core states were explicitly represented by nonlocal projection operators. A search in parameter space revealed three separate regions in which the Fermi surface generated by the pseudopotential was a good fit to experimental magneto-acoustic calipers and extremal sectional areas. One of the regions investigated was equivalent to the Animalu–Heine pseudopotential for mercury and a second was very similar to the Evans pseudopotential which has been used for liquid mercury. Although there were strong resemblances in the band structures generated by the different classes of pseudopotential, the symmetry characteristics of the bands were different. The nonlocal operators had a strong influence on the Fermi energy with p-like and d-like operators causing an increase in the Fermi energy. The influence of spin–orbit coupling and more general questions of pseudopotential theory and band symmetry were also considered.

1. Ten manurial treatments were applied annually to cattle cabbage grown in a six-course rotation for 7 years. Samples were taken in the early winter each year, and from five harvests taken at fortnightly intervals in the last year.2. The dry-matter yields each year closely followed the weather conditions during the growing season. There was no significant fall in the dry-matter yield during the last season. The treatments supplying phosphorus or phosphorus and potassium substantially increased yield, but the application of nitrogen did not.3. The application of nitrogen, potassium or phosphorus increased the levels of these constituents in the crop in practically all cases. The application of phosphorus produced hearted plants which contained significantly less dry matter than the openleavod plants produced in its absence. The levels of ether extract, crude fibre, ash, silica and magnesium wore not significantly affected by the manorial treatments.4. There was little variation in composition as the season advanced except for significant increases in the crude-fibre levels and decreases in the nitrogen-free extractives levels.5. The distribution of the chemical components was investigated in the outer leaves, heart leaves and stem of the plant. This was compared with that in the marrow-stem kales.6. The chemical composition of the cattle cabbage compares fairly closely with that found for the marrow-stem kales grown under similar conditions. It is, however, lower in dry matter, crude fibre, magnesium and chlorine. It may be considered as a replacement for marrow-stem kale as a source of crude protein and all the major minerals except chlorine and possibly magnesium.

A semiempirical pseudopotential for crystalline mercury has been determined using a fitting procedure to experimental dimensions of the Fermi surface. Three separate classes of pseudopotential were found to be consistent with measured calipers of the Fermi surface. One pseudopotential is equivalent to the Evans's pseudopotential used for liquid mercury.

The construction and properties of 137Cs sources suitable to replace radium tubes and needles in general use are described. It is found that the exposure distribution in water around these sources is very nearly the same as that produced by their radium equivalents. The results of a test for the presence of 134Cs are given showing that the contribution of this isotope to the dose-rate is less than 6 per cent. The relative advantages possessed by 137Cs for this application are discussed.

The heave, pitch and roll equations of motion for an Air Cushion Vehicle are derived. The dynamic response to a random seaway is predicted from the linearized perturbation equations and compared with experimental tests of a subscale dynamically similar model operating in a towing tank. Frequency domain seakeeping analysis to determine acceleration response, frequency of bow slamming, structural loads, and relative motion between two craft is demonstrated. Because the atmosphere is not scaled during subscale model tests, an appreciable dynamic distortion is reflected in lift system physical parameters. This scaling problem is discussed and avenues of further subscale model experimental research are suggested.

When superficial X-ray therapy sets are operated with a number of different combinations of kilovoltage and external filtration to produce different qualities of radiation it is desirable that some form of interlocking should be incorporated to prevent the application of an incorrect kilovoltage to the X-ray tube when a particular filter is in use. A method providing for automatic selection of kilovoltage when a filter is inserted in the filter carriage has been described by Herbert and Marshall (1951). The method described here, which is used on a superficial X-ray set with a Variac voltage control, employs only micro-switches throughout, provides for visual indication of the filter in use, and allows the voltage applied to the primary of the H.T. transformer to be read directly. Three qualities of radiation are normally used, obtained by the following combinations of kilovoltage and external filter: (a) 60 kV, no external filter; (b) 100 kV, 1 mm Al; (c) 140 kV, 2 mm Al.