Chromatic Processing Research Articles

Color vision in the peripheral retina.

Until recently, color vision in the peripheral field has been thought to be substantially less developed than color vision in the central field. Although the exact dimensions vary from study to study, most estimates of peripheral chromatic perception place the limit of trichromatic vision at no more than 30 degrees from fixation; the visual field is thought to be completely color blind at about 50 degrees of eccentricity. Within the last 10 years, an increased understanding of the changing spatial scale in the peripheral field has led researchers to reevaluate what is believed about peripheral function. We now know that virtually every measure of peripheral color perception can be improved by using a suitably large stimulus in the peripheral field. This paper examines current and past perspectives on peripheral color function, and describes two studies which demonstrate that peripheral and central chromatic processing are the same to the first order if the changes in spatial scale and photopic sensitivity with eccentricity are considered.

Pretreatment of Galvanized Surfaces Prior to Powder Coating

SummaryThe paper covers the various methods and processes suitable for the pretreatment of galvanized steel surfaces prior to the application of powder coatings, drawing upon results from industrial coating installations as well as those from laboratory testing. It is important to differentiate between the types of zinc coated surfaces and in particular between strip-line galvanized steel sheet and heavy conventional hot dip galvanized steel. The main precleaning processes in use are alkali cleaning/etching and acid etching, the choice being influenced by the method of application and the thickness of the overlying zinc layer.Conversion coatings are necessary to ensure adequate service life and here the choice lies between chromating and phosphating. Accelerated corrosion tests have indicated that certain yellow Chromate processes are to be preferred for the treatment of thick galvanized surfaces, whereas Chromate, chromate/phosphate and micro-crystalline zinc phosphate processes may all be suitable for u...

Effect of Processing Mode on the Degree of Motor asymmetry in the Manual Stroop Test

In a reaction-time study using conflicting Stroop colour-word stimuli and unimanual-choice responses, Schmit and Davis (1974) have provided data incidentally showing a right-hand advantage for the verbal processing of the material, contrasting with a left-hand advantage for the chromatic processing of the same material. The present experiment successfully replicated the interaction effect, using a within-subject design and a simplified procedure. This effect indicates the preferential involvement of the left hemisphere in the verbal processing of the Stroop material. More interestingly, it shows that it may be efficient to use the very simple laterality factors of the output sphere — such as the hand used to make the response — for the study of hemispheric lateralization of cognitive function.

Chromate film used for chemical corrosion control on gold-plated PCB connectors

Electrical intermittencies in nuclear submarine navigational computers can result from degredation of gold-coated contacts by insulating films, the latter identified as principally composed of organics and silver sulfide. The films can be removed, but without appropriate measures, they recur. To retard insulating film build-up, a protective, noninsulating chromate surface treatment was developed; it has proven effective in extending service life. Because protection arises from a surface modification, investigation of the chromating process requires the use of surface-sensitive techniques. Analysis by AES, SAM, XPS, EMA and RBS reveals the presence of a thin (< 30 Å) layer, rich in Cr 3+ on top of the gold. This contrasts with much thicker films incorporating Cr 6+ species found in chromate films grown for the protection of Zn, Cd and Al. The absence of Cr 6+ species suggests the chromate film on gold protects via a physical rather than electrochemical mechanism. The chromate film continuity and composition can be adversely affected by mechanical contact, tarnish growth, and substrate microheterogeneity. Copper compounds are implicated in the occasional development of insulating films during field application of the chromate treatment.

Duration thresholds for chromatic stimuli

The duration necessary to detect chromatic stimuli was measured for wavelengths between 463 and 620 nm. Stimuli were presented either in hue substitution (replacement of white by a chromatic stimulus of matched luminance) or as increments. Two observers viewed a 1 degrees 45' homogeneous white field. A trial consisted of replacement of the central 40' of the field by a chromatic stimulus. In substitution mode the white field was 2.4 cd/m2., the chromatic replacement was of matched luminance using heterochromatic flicker photometry (HFP). In increment mode, the white field was decreased to 1.2 cd/m2., the chromatic replacement remained at 2.4 cd/m2. In substitution mode, duration threshold varied from approximately 3--4 ms for the spectral extremes to 45--66 ms at 570 nm. Detected stimuli were always seen as a change in chromaticity. In increment mode, thresholds were in the 2--4 ms range with no dependence upon spectral composition. Detected stimuli were seen either as changes in chromaticity or brightness. A control experiment indicated that HFP did establish equivalent luminance for the hue substitution mode. We conclude that duration thresholds in substitution mode reveal chromatic processing channels; duration thresholds in increment mode are mediated by chromatic and/or achromatic processing channels.

Chromatic information processing.

The investigation of visual processing mediated solely by chromatic information requires conditions preventing a subject's use of the luminance differences normally accompanying a chromatic change. In Experiment 1, which involved a discriminative reaction time (RT) task, chromatic and white stimuli of the same luminance were presented on a dimmer achromatic background. Subjects were instructed to respond only to the chromatic stimuli. RT was slowest at 570 nm and somewhat faster to short wavelengths than to long wavelengths. In Experiment 2, which compared two discriminative RT tasks, RT was faster when subjects responded to color than when they responded to white. Experiments 3 and 4 demonstrated that a brighter white surround decreased the perceived brightness of chromatic stimuli as well as their perceptual similarity to white, but did not affect RT. The results are discussed in terms of the response strength of the chromatic processing channel.

クロメート処理液のリサイクル化-その実施例

クロメート処理液のリサイクル化-その実施例

Wavelength effects on simple reaction time

Simple reaction time was measured to spectral lights matched photometrically in luminance. When these lights were presented on a dimmer achromatic background, reaction time did not vary as a function of wavelength. Moreover, reaction times to white and chromatic lights were the same. When the luminance of the background was the same as that of the chromatic lights, reaction time increased and showed a strong effect of wavelength. Reaction time in this condition appeared to follow a saturation function. The results are described in terms of the operation of achromatic and chromatic processing channels.

調色法・染色法によるX線写真画像の研究

This study was about Ag particle of roentgenographic image with coloured method by chemical change. When this image Ag particle was acidified by potassium ferricyanide it changed into Ag ferrocyanide because of chemical reaction. Image Ag particle change into colouring matter chemical compound which didn't dissolve in liquid because of chemical reaction of the metal salts solution selected. This Ag particle of roenthenographic image coloured is monocolour. The chromatic method was called coloured method by chemical reaction. I attempted together with dyeing by dyestuff for blend into each other, too. When I attempted coloured method by chemical reaction. It attempted with experiment of different kind for find out processing solution does and simplified process. The experimental result of this research was good effect with Sharpness, Contrast, Latitude and Density. For one thing, it was rising of density ; for another, it was rising diagnostic range of colour difference. The processing solution of iron coloured by chemical reaction was one bath method and the original solution was augmentative action with density. The result was rising of diagnostic range for colour difference and I could decrease the radiological exposure dose for rising of density. Namely I selected first coloured processing solution by chemical reaction which was augmentative action with iron chromatic processing solution.

Opponent-process solutions for uniform Munsell spacing.

An iterative method is used to transform the chromaticity coordinates of the Munsell samples into another coordinate system such that the transformed values are spaced in accordance with the perceptual spacing of the colors. Acceptable transformations are restricted to those having an opponent-process form; brightness information is assumed to be conveyed by an independent channel. Under these conditions, the optimal transformation based on two chromatic processes is similar to one stage of the Müller–Judd formulation. By changing the constraints imposed on acceptable transformations, however, support can also be found for the Hering model. Therefore, even though many quantitative transformations can already be excluded, more data are needed before this method can be applied as a decisive test for models of color vision.

PREPARATION OF LIVER TISSUE FOR THE EVALUATION OF MITOTIC ACTIVITY.

High quality images of nuclei for mitotic counts in mouse liver tissue in which the various mitotic phases can be classified, are obtained by fixing in Lillie's neutral buffered formaldehyde solution, 8-24 hr at 4 C and then immersing 2-4 hr in Sanfelice's fixative (1% CrO3, 16; formalin, conc., 4; acetic acid, 1) followed by washing in tap water 12-24 hr. To count in zones of the same fixation quality, the procedure devised is as follows: Run the entire right caudoventral (triangular) lobe through the fixation and chromating process. Wash and cut off the concave surface to provide a flat face for sectioning. In the sections obtained, three zones can be distinguished. An external one unsuited for counts, a deeper zone suitable for counts, where the fixation is very good and a third or central zone where the fixation becomes gradually worse. Counts are made in microscopic fields which are selected as a row, one field width from the external surface of the organ. This fixation and orientation minimizes the ...

Theoretical analysis of anomalous trichromatic color vision.

Anomalous trichromatic color systems are examined within the framework of a three variable, bimodal opponent-colors theory. Specific types of anomaly are assumed to be related to specific changes in the normal photoreceptor distributions and to impairments in the normal chromatic response processes. The aberrant color equations, color sensations, and color discriminations of both protanomalous and deuteranomalous observers are shown to be meaningfully related to the postulated, systematically aberrant visual mechanisms.

Figural After-Effects with Colored Stimuli

Kohler and Wallach1 have explained Gibson's tilted-line effects' and other phenomena, in terms of a physiological model which has far-reaching perceptual implications beyond the figural after-effects themselves. Although the model was developed for the achromatic colors-black, grays, white-it would seem worthwhile to establish its limits of applicability, and, possibly, to aid understanding of the chromatic processes, by determining to what extent the 'contour-repulsion' figural after-effects are related to chromatic color.

The mechanism of a chromate process for the separation of the lanthanons and yttrium

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The Dyeing of Cotton with Mineral Khaki—Part III

Journal of the Society of Dyers and ColouristsVolume 58, Issue 2 p. 32-36 The Dyeing of Cotton with Mineral Khaki—Part III The Chemical Changes accompanying the use of a Standing Bath in Development by the Chromate Process E. Rack, E. Rack Clothworkers Research Laboratory and Textile Chemistry Laboratory Leeds UniversitySearch for more papers by this authorF. M. Rowb, F. M. Rowb Clothworkers Research Laboratory and Textile Chemistry Laboratory Leeds UniversitySearch for more papers by this authorJ. B. Speakman, J. B. Speakman Clothworkers Research Laboratory and Textile Chemistry Laboratory Leeds UniversitySearch for more papers by this author E. Rack, E. Rack Clothworkers Research Laboratory and Textile Chemistry Laboratory Leeds UniversitySearch for more papers by this authorF. M. Rowb, F. M. Rowb Clothworkers Research Laboratory and Textile Chemistry Laboratory Leeds UniversitySearch for more papers by this authorJ. B. Speakman, J. B. Speakman Clothworkers Research Laboratory and Textile Chemistry Laboratory Leeds UniversitySearch for more papers by this author First published: February 1942 https://doi.org/10.1111/j.1478-4408.1942.tb02168.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Volume58, Issue2February 1942Pages 32-36 RelatedInformation

The Treatment of Magnesium Alloys in Hot Chromate Baths

Methods of protecting magnesium and its alloys against corrosion are briefly reviewed. The R.A.E. hot Chromate processes are described and details of bath composition, maintenance and operating con...

The chromate process of tanning

Journal of the Society of Chemical IndustryVolume 3, Issue 12 p. 615-620 Article The chromate process of tanning Mr. W. J. A. Donald, Mr. W. J. A. DonaldSearch for more papers by this author Mr. W. J. A. Donald, Mr. W. J. A. DonaldSearch for more papers by this author First published: 29 December 1884 https://doi.org/10.1002/jctb.5000031211AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Volume3, Issue1229 December 1884Pages 615-620 RelatedInformation