High-quality Lines Research Articles

The Production of a Spiral Slit Image

A requirement for a single turn transparent spiral slit of minimum radius 1.5 in. with a line width of 25µ could not be met by conventional photographic reduction, owing to the incompatibility of resolution and covering power. This paper describes a microphotographic method which uses the resolution characteristics of a microscope objective to produce a high quality line of constant width by projecting a stationary image onto a photographic plate which is moved to trace the required shape. The construction of the apparatus used, the problems encountered and the results obtained are discussed.

Highlights of Ophthalmology.

The rather unique Highlights owe their existence largely to the energy of its indefatigable editor, Dr. Boyd. Immeasurably helped by the high quality line drawings which illustrate many of the articles, this publication has acquired a high reputation for its presentation of clinical and, particularly, surgical problems. This issue merits considerable praise, especially the excellent section on unilateral exophthalmos written by Ira Jones, the section on plastic surgery, and the large division devoted to various aspects of corneal transplantation surgery. Surgeons interested in these fields will find the opinions of numerous international authorities most interesting to review. It is to be hoped that the author will continue the series.

STUDIES OF FACTORS AFFECTING COOKING QUALITY OF YELLOW PEAS

The largest peas from well-matured plants and pods, and those grown at a soil pH of 6–7, were of the best quality for soup manufacture. A genetic basis for cooking quality was suggested by the consistent superiority of the variety Chancellor to Arthur, and by the fact that high quality lines selected from the variety Chancellor maintained this status for several generations.

Strain Variation in Albumen Quality Decline of Hen’s Eggs

ABSTRACT INTRODUCTION THE initial quality of fresh shell eggs varies among breeds and strains. As early as 1934 Knox and Godfrey noted that eggs from White Leghorn hens had a significantly greater percentage of thick white than eggs from Rhode Island Red hens. Grimes (1953) observed that standard-bred strains tended to produce eggs of superior albumen quality when compared with eggs laid by crossbred and incrossbred “strains” although the quality of eggs from the standard-bred strains was less uniform. The fact that breeds and strains do lay eggs of significantly different albumen quality has been supported by many other workers including Dawson et al. (1953), Cotterill and Winter (1954), Johnson and Gowe (1956) and King and Hall (1955). Several studies have shown that initial albumen quality is an inherited trait. Lorenz, Taylor and Almquist (1934) developed high and low quality lines based on percentage of thick albumen in the eggs. Knox . . .

The Possibilities of Reduced Television Bandwidth

A solution is sought to the following problem: Given a wide bandwidth of the order of 50 kc, devise standards such that the entertainment value shall be maximized. Four applications are considered: tape recording at a tape speed of 15 inches per second; telephone conversation accompaniment over high-quality telephone lines; long-distance wire-line transmission over high quality telephone lines; and short-wave transmission over a 120 kc channel. Bandwidth reduction is achieved through reduced resolution, reduced field frequency, increased interlacing ratio, the use of dot interlace, and the use of quantizating and coding. The scanning frequencies and synchronizing signal are derived for each case. In addition, for the short-wave system, a method of combating multipath transmission is suggested.

Analytical yield investigations on New Zealand wheat: IV. Blending varieties of wheat

1. An endeavour was made to obtain a blend of Tuscan wheat with a high quality line which would yield as much as Tuscan, at the same time possessing a superior baking quality. Of the eleven lines which were blended with Tuscan, nine blends returned yields corresponding to the expectation calculated from the pure varieties, and two blends yielded more than the expectation; these increases were not statistically significant.2. Tuscan, three lines and their blends were submitted to yield analytical treatment. The yield characters of the components of blends were compared with their yield characters when grown by themselves. Whilst the yields per plot of the blends corresponded to the expectation, the yield analyses revealed that the component varieties exerted a modifying influence on each other, which was different in each of the three trials. Tuscan demonstrated its aggressiveness by depressing in every case the yield characters of the lines with which it was blended.

Phenomena accompanying transmission with some types of star transformer connections — II

1. Hysteresis, as well as variation of permeability, gives rise to harmonics of considerable magnitude in the exciting current of a transformer; the components from the two sources are in quadrature for each harmonic. 2. There is a fallacy in the idea that the harmonics in the exciting current of a transformer are entirely wattless. 3. For transmission lines of modern lengths, the effect of the line is to reduce the third harmonic voltage between neutral and line terminals of a star-star connected bank of transformers having grounded neutral on the line side only. 4. In transmission with star-star transformer banks having grounded neutral on the line side only, the interrelation of line susceptance from conductor to ground in series with the varying susceptance of the individual transformers may cause the total m.m.f. of one of the transformers to pass through zero at the same instant as the impressed e.m.f.; and thus, give opportunity for a reversal of this transformer due to inertia, thereby producing a periodically reversing leg and abnormal voltages. 5. In a similar system with high quality line insulation, the effect of atmospheric charges on the line conductors may be to cause the transformer of the bank to assume relations with one leg permanently reversed when energized from the station side; thus, imposing unbalanced voltage conditions on the bank and producing, in two of the units, fundamental frequency components of voltage 264 per cent of normal. 6. Combinations and accentuations of the above causes may, through natural requirements, give rise to a double frequency pulsation of the potential of the hypothetical neutral of the line conductors; thus, producing, in the leg voltages, second harmonic components of extremely large dimensions which are limitless so far as is yet known. 7. The above applies also in case a group of star-connected ironclad reactors, such as auto-transformers without tertiary windings, are employed to ground the neutral of an otherwise isolated neutral transmission. 8. Results, obtained in the laboratory with a three-phase star-star connected bank of transformers feeding condensers between line conductors and line side neutral, though not yet sufficiently extensive to confirm all of the above statements, show that the voltages from line terminals to neutral are in considerable measure independent of the primary impressed delta voltages so far as concerns wave shape and frequency.

Phenomena Accompanying Transmission with Some Types of Star Transformer Connections-II

1. Hysteresis, as well as variation of permeability, gives rise to harmonics of considerable magnitude in the exciting current of a transformer; the components from the two sources are in quadrature for each harmonic. 2. There is a fallacy in the idea that the harmonics in the exciting current of a transformer are entirely wattless. 3. For transmission lines of modern lengths, the effect of the line is to reduce the third harmonic voltage between neutral and line terminals of a star-star connected bank of transformers having grounded neutral on the line side only. 4. In transmission with star-star transformer banks having grounded neutral on the line side only, the inter-relation of line susceptance from conductor to ground in series with the varying susceptance of the individual transformers may cause the total m. m. f. of one of the transformers to pass through zero at the same instant as the impressed e. m. f.; and thus, give opportunity for a reversal of this transformer due to inertia, thereby producing a periodically reversing leg and abnormal voltages. 5. In a similar system with high quality line insulation, the effect of atmospheric charges on the line conductors may be to cause the transformers of the bank to assume relations with one leg permanently reversed when energized from the station side; thus, imposing unbalanced voltage conditions on the bank and producing, in two of the units, fundamental frequency components of voltage 264 per cent of normal. 6.