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Bedforms are defined and their variety outlined. Aeolian bedforms are shown to arise spontaneously by a two-way interaction between surface form and airflow involving piecemeal material transfer between them. They eventually reach a dynamic equilibrium and transverse elements migrate downwind. Aeolian bedforms may be compounded of elements from four groups i.e., draas, dunes, aerodynamic ripples and impact ripples, each subdivided into transverse and longitudinal elements. There are no transitional forms between the elements of one of these eight subgroups and those of another and they are interpreted as being formed by different mechanisms. The possible nature of these mechanisms is considered and qualitative models for the development of generalised transverse and longitudinal elements given. Transverse and longitudinal elements may be combined in three different ways according to whether or not one clement is displaced half a wavelength on crossing the other. [ABSTRACT FROM AUTHOR]

Repeatable laboratory dyeings are necessary for evaluation of fiber dyeability, dyestuff strength or shade matching. A laboratory method for dyeing polyester at the boil in a low temperature Launder-Ometer bas been studied. Leaks from the stainless steel containers are avoided by using a Mason jar lid for a gasket. Dye depths were measured by Hunter L values or Color-Eye reflectances at maximum absorbance wavelengths. Three disperse dyes in self shades were included in this study. Controlled conditions permitting repeat dyeings within 1-2% were determined. Dyeings in open beakers were unsuccessful. [ABSTRACT FROM AUTHOR]

The use of color difference formulas in the textile industry is somewhat hampered by the relatively low degree of correlation obtained between color differences calculated with a color difference formula and average visual judgment as represented by acceptability judgments of matches around standards. Best results in practical work could be expected from a formula based on ellipses representing the average visual judgment of a group of observers. Not enough data exist presently to make such a formula possible. This investigation adds significantly to existing acceptability data. Acceptabilities for a total of 180 samples around ten standards, located mostly in areas of color space where no such data existed, have been determined. from judgments under artificial day-light by 16 skilled observers. Approximate 50% acceptability contours developed from this data fit in well with contours of previously published data. Two areas of sudden discontinuity in the direction of the major axis of the acceptability ellipses were found at dominant wavelengths of approximately 494 and 570 nm and may be of significance for the theory of color Vision. Sixty-four samples around four standards were also observed and judged Under incandescent light. No significant difference in acceptability judgment Under tungsten light as compared to daylight could be detected. [ABSTRACT FROM AUTHOR]

An instrumental and mathematical method is described to evaluate calculated small color differences in coloristically meaningful terms. The strength difference is determined at or near the wavelength of maximum absorption and after mathematically adjusting the sample to equal strength with the standard the "chromatic color difference" (color difference at equal strength) is calculated using a MacAdam color difference formula. A computer program to accomplish this is described. [ABSTRACT FROM AUTHOR]

The article discusses the findings of a study on the causes of sliver irregularity in wool-gilling. The study concluded that the gilling process involves two main different sources of disturbances, namely, the input irregularity, and the faller-bar action. A theoretical analysis has revealed that the resultant output irregularities are composed of two independent components corresponding to these two sources of disturbance. The study confirmed through a spectral analysis of the experimental data that the gilling process causes a considerable amount of additional irregularity to occur in the gilled sliver. Additional irregularity is mainly contributed by a periodic wave with a wavelength approximately equal to the pitch of the fallers times the front draft ratio.

A method for measuring the variance between ultra-short lengths of yarn is presented and shows that the reported flattening of the B(L) curve to a constant value in the 5(0) region does not occur at lengths of down to at least 0-1 cm. The curve continues to rise logarithmically as the length decreases, possibly as far as 0· 045 cm, though detection imperfections render readings at this length open to some doubt. Yarn irregularity is shown to be strongly dependent on fibre length and on yarn fineness, particularly at short test lengths, and the possibility of periodicities at less than 1-cm ‘wavelengths’ is shown to exist. [ABSTRACT FROM AUTHOR]

The limitations of sliver autolevellers are studied in terms of a linear model based on the perfect drafting of straight parallel fibres of equal length. The basic factors which limit their performance are the presence of 'dead times' in the control loops, and the impossibility of obtaining a direct measure of fibre-end density. This means that other related variables, such as thickness or drafting force, are used as approximations. Autolevellers are generally divided into two basic types, namely open-loop and closed-loop, depending on whether the error is measured before the back rollers or after the front rollers, respectively. The behaviour of each system is studied and compared in terms of response functions expressed with respect to wavelength on the output material. Results are computed for a few basic control actions and the values of the control parameters for optimum response are determined. A third type of autoleveller is identified in this paper as one in which the error is measured in between the drafting rollers. This has the effect of combining both open-loop and closed-loop systems. In the case of an error in thickness it is shown that this method gives results which compare favourably with either of the other two. An autoleveller based on the use of drafting force as the controlled variable is also shown to belong to this category and gives results which are significantly better at short wavelengths. For a sliver with variable fibre length it is shown that in general the fibre-length distribution function varies with position along the length of the sliver. For control purposes this variation is considered as an additional unknown variable, but is unfortunately not continuously measurable. This means that control action must be based on incomplete information and this, therefore, represents another contributory factor limiting control ability. [ABSTRACT FROM AUTHOR]

The article presents a study which assesses the spectral composition and effects of light intensity on woodland plants in Heidelberg, Germany. It suggests that wavelength must be measured first in order to determine which woodland is lighter or darker. It reveals that the composition falls on a horizontal surface about 25 centimeters from the ground where the sky is clear and discrete. The study also claims that the regression of plant growth on light and form of apparent relation influence the color of the light measured.

The article reports on spectral measurements. Spectral measurements are developed to measure wavelengths on plant's photosynthesis and to evaluate biochemical reactions. They include measurement of light and energy using the units of lux, lumens, joules, watts and nanometers (nm). They are consisted of different elements such as dispersion, prisms, gratings, interference filters, wedge filters, detection of dispersed light, and light source. Spectral measurements are used in measuring incident radiation, photographic light, absorption or emission of light, and fluctuations of the light source. Its measuring instruments include spectrograph, spectroscope, spectrophotometer, and spectroradiometer.

The article presents an overview of light research and its effect on plant and animal life. Light energy exerts an influence on human body chemistry as it does through the process of photosynthesis in plants. Much discussion has been on the direct connections between a photo receptor mechanism of the retina and the hypothalamic nuclei. Over the past forty years, observations on plant and animal growth responses to variations in the wavelength distribution of light energy have resulted from taking time-lapse pictures of flowers blooming and plant growth. At the Miami, Florida, Seaquarium, Warren Zeiller, curator, reports curing fish of exophthalmus by subjecting them to treatments of near black ultraviolet identical to that used in the Well of the Sea restaurant. A researcher reported success in rehabilitating some of the toughest psychological criminals by means of horticultural therapy. A reversal occurred in the manufacture of artificial lights with an ever greater distortion of the wavelength energy from that of natural sunlight.

The section "Chemical Testing & Analysis," presents information on soiling in fabric as well as evaluates detergency. It reports that the soiling in carpets can be reduced by the use of appropriate color, using white material that have been finely divided as finishes and by using a fiber that has high light-scattering coefficient. It is noted that the reflectance of a carpet can be increased with pile compaction. The method of selecting the wavelength of light that's nearest to the dominant wavelength by using interference filters is considered to be the best. It is noted that sodium lauryl alcohol sulphate has been found to be the best surface-active agent after comparing several surface-active agents as detergents for cotton.

The essay discusses issues related to the concept of a single radiant energy metric. The fact that the amount of energy in a quantum of light is wavelength dependent, there is no way in which a quantity of radiant energy can be described by less than two numbers. Among the factors that must be considered in making measurements of solar radiation are the measuring instrument, latitude and cloudiness. The author attempts to point out that there are many facets to making light measurements, including the selection of radiation measuring instrument.

The article reports on the communication breakthrough in the U.S. The wireless telephone mechanism invented by the Americans does transmission on wavelengths about one-half of that employed on long distance wireless telegraphy. The device was tested by Bell Telephone System engineers by transmitting a message by wireless telephone from American station at Arlington to the military station at the Eiffel Tower in Paris. The test was a successful one.