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This paper aims to compare visual (Munsell) and instrumental (CIELAB) attributes of SCOTDIC colour standards.

SCOTDIC cotton and polyester standards of defined hue, value and chroma were subjected to spectrophotometric assessment for finding the corresponding instrumental parameters. The visual and instrumental parameters were compared.

The correlation between SCOTDIC value and CIELAB lightness is quite high. Correlation coefficient between SCOTDIC hue and CIELAB hue angle and the correlation between SCOTDIC chroma and CIELAB chroma were only moderate because the CIELAB chroma varied widely at higher chroma. When the standards of SCOTDIC hues having erratic hue angles at two extremes are excluded, the Correlation coefficients between SCOTDIC hue and CIELAB hue angle become high.

The psychophysical data (visual) are difficult to match with physical data (instrumental).

The object of the present research is to study and compare visual (Munsell) and instrumental (CIELAB) colorimetric parameters. Munsell scale is physically exemplified by SCOTDIC fabric samples available in two sets, namely, cotton and polyester sets.

Commercial natural dyes are quite costly as manufacturers are to follow multi-step extraction and purification procedures for standardisation purposes. Upon cost comparison, they lose in the market to synthetic dyes. However, in the handicraft sector, reproducibility may be of lesser importance against cost. In the present study, a domestic method of dyeing silk with the aqueous extract of raw plant/tree components (flower, leave, bark and root) by using a natural mordant and alum will be described. Good dyebath exhaustion and washing and light fastness are observed for some of the natural colouring matters.

The purpose of this paper is to compare light fastness assessments by exposure of fabric dyes with various dyes in daylight and an artificial xenon arc lamp.

Cotton fabric dyed with 66 reactive, vat, azoic and direct dyes dyed in different depths were exposed to daylight and Xenon arc lamp for assessment of light fastness by standard methods. The light fastness rating and fading hours by the two methods were analysed and compared statistically.

The correlation between the corresponding light fastness rating (LFR) measured in Xenotest and daylight is quite high (0.93). The logarithmic correlation coefficients between fading hour (FH) and LFR in Xenotest and daylight are 0.95 and 0.88, respectively. For Xenotest, the assessed LFRs are same as those predicted from geometric progression up to LFR of 5.5, and thereafter, the former is higher. On the other hand, in the case of daylight, the assessed LFR is lower. Assessments for three successive seasons showed high repeatability in case of Xenotest and moderate repeatability in case of daylight. Assessments for three successive seasons showed high repeatability in case of Xenotest and moderate repeatability in case of daylight.

The exposure conditions in daylight cannot be controlled or standardised, whereas the exposure in Xenon arc lamp in the accelerated fading instrument can be strictly controlled. These differences in exposure control may affect the repeatability of experimental findings.

Inconsistent ratings may be because of little deterioration of samples during storage, as well as seasonal variation of daylight.

There are no direct social implications.

The researches on the comparison of the two light fastness assessment methods have not been reported in any recent publication to the best our knowledge.

In recent times, wool- and silk-blended fabrics are popular for creating glamourous products. Silk is blended to wool for creating more lustrous effect and to impart strength; on the other hand, wool is responsible for resilience, softness and warmth properties. Chemically both the fibres are protein-based, but the amount of amino acids is different. Due to this, the dye absorption behaviours of the two fibres from the same dye-bath are different. Wool is become darker than the silk fibre, if both the fibres are dyed together in a single bath dyeing process.

Here the wool fibres are first pre-treated with a commercial synthetic tanning agent (syntan) Mesitol HWS at three different pH values of 2.2, 3.2 and 4.2 and at three different concentrations: 5, 10 and 15 per cent. Then the syntan pre-treated wool fibres are dyed together with silk fibres maintaining the blend ratio as 80:20 by Telon Red MR, Telon Yellow M4GL and Telon Blue MRLW with sodium sulphate at three different concentrations of 10, 20 and 30 per cent.

The dye absorbency of the syntan-treated wool fibres decreased with increase in syntan concentration, whereas the colour strength of silk fibres increased. The resist effectiveness of wool fibres is increased from 6 to 59 per cent with increase of syntan concentration. So after the dyeing process, the colour strength of syntan-treated wool fibres are almost same with the colour strength of silk fibres. The washing fastness of the samples is improved, and wash fastness behaviour of both wool and silk fibres is almost same.

This paper gives an idea about the one bath dyeing process of wool- and silk-blended fabrics to achieve solid dyeing effect.

The purpose of this study is to optimize single-bath dyeing process of wool and silk blend, to achieve uniform colour strength for both the fibre after the dyeing process. Due to different absorption characteristics of wool and silk, two-stage dyeing is preferred in the industry. If the fibres are dyed together, the wool fibre becomes darker and the silk fibre becomes lighter after the dyeing process. Solid dyeing effect can be achieved using a single-bath dyeing process.

The dye-acceptor sites in the wool fibre are first blocked using one commercial syntan Mesitol HWS. Then, the syntan-treated wool and silk fibres (80:20 blend ratios) are dyed with Telon Navy AMF dyes in the presence of sodium sulphate. To explore the influence of Syntan, sodium sulphate and the experimental conditions on the dyeing process and to optimize the process, central composite design (CCD) of four factors and three levels was tested.

The design process is optimized using four independent variables: Mesitol HWS concentration, sodium sulphate concentration, pH of dyebath and temperature of dyeing. Three levels of Mesitol HWS concentration (5, 10 and 15 per cent), sodium sulphate concentration (10, 20 and 30 per cent), pH (2.5, 4 and 5.5) and temperature of dyeing (70, 80 and 900°C) were selected for this study. These variables are optimized using response surface regression equation of the ratio of K/S wool and K/S silk. The predicted equation matched well with the experimental data.

This paper proposes the use of one-bath dyeing process of wool and silk blend fabric to reduce the dyeing time, process step and to save water.

Layered manufacturing with curved layers is a recently proposed rapid prototyping (RP) strategy for the manufacture of curved, thin and shell-type parts and the repair of worn surfaces, etc. The present investigation indicates another possible application area. In case of flat-layered RP of computer-aided design models having randomly located, small-dimensioned but critical surface features, adaptive slicing is resorted to. Large number of thin slices have to be employed to preserve the critical features. In contrast, a considerably lower number of curved thin slices would be required to preserve such surface features in case of RP with curved layers.

The method of preservation of critical features by RP with curved layers is formulated and demonstrated for two clusters of critical features on the surface of a part. A minimum number of such curved layers is identified by application of genetic algorithms (GAs) in case of a simple example. GA evolves the shape of the curved layer passing through the lower cluster so as to make a curved layer pass through the upper cluster of critical features.

In the example part, a 21 per cent reduction in the number of layers is achieved by the application of adaptive curved layers over adaptive straight layers.

The novelty of the concept is the proposed use of curved layered RP with adaptive slicing for the preservation of critical features in final prototyped part. This methodology, applied to part with two distinct clusters, leads to reduced number of layers compared to that obtained in flat-layered RP.

To calculate the volume deviation between a CAD model and built‐up part in 5‐axis laminated object manufacturing employing direct slicing with first‐order approximation.

It is proposed here that the deviation between the CAD model and the built‐up part, which is normally calculated as a linear dimension in specific 2D sections of the CAD model, be treated as a volume (as it actually is), for higher accuracy in subsequent calculations. An algorithm has been developed and implemented for identification and calculation of volume deviation, considering all possibilities.

It has been conclusively shown that volume deviation consideration results in improved feature recognition and less approximation.

Increase in complexity of the CAD model leads to a considerable increase in the volume deviation computation time. Future research in this area would focus on optimization and calculation of the slice heights based on volume deviation.

Calculation of volume deviation would help eliminate the loss of intricate features in a complex surface and thus improve feature recognition. Slice height calculations based on volume deviation would reduce the deviation between the actual model and the built‐up part.

A new method has been developed for the calculation of volume deviation that could be implemented in the rapid prototyping software packages so as to build prototypes with higher accuracy.

The purpose of this paper is to synthesize findings on the effects of existing paid parental leave programs on infant mortality rates (IMR) in the USA as an attempt to aid in efforts for the development of a national paid parental leave policy.

Three articles were reviewed to analyze findings on the effects of existing parental leave programs on IMR in the USA.

The results from the three studies analyzed indicate that unpaid parental leave and parental leave with partial wage replacement can reduce IMR in households with college educated, working mothers.

This review is limited due to only having three studies available to synthesize that pertained to the USA. Implications for future research are to examine the effects of fully paid parental leave programs offered by individual organizations on IMR in the USA.

Providing a needs-based income replacement policy to mothers who wish to take parental leave after the birth of a child may be the best policy to decrease IMR for infants from all socioeconomic backgrounds.

The findings in this review will aid in the ongoing efforts to develop a national paid parental leave policy in the USA.

This paper aims to develop an efficient surface‐plane intersection (SPI) algorithm for direct slicing of free‐form surfaces to be produced by layered manufacturing.

A semi‐analytical method for direct slicing has been formulated and tested on Bezier and B‐spline surfaces commonly used in CAD modeling. This method solves for the intersection points by a “root” finding procedure and establishes their connectivity, unlike the conventional “marching” procedures.

The proposed algorithm solves intersection contours between free form surfaces and planes. The solution procedure is efficient with respect to computational time and accuracy (feature detection) over some of the conventional SPI strategies. The method involves a global solution procedure in contention with the traditional methodologies which are generally spatially distinctive in approach.

Use of higher order terms in the representation of parametric surfaces makes the algorithm computationally intensive and time‐expensive.

This algorithm would be of practical use in the direct slicing of free form surfaces used in CAD modeling. Direct slicing methods solve for the actual intersection of surface and plane without resorting to “tessellation.” Reducing the computation time and detection of features within a given resolution is of primary importance for developing commercial rapid prototyping software, which is achieved in the present paper.

A novel method has been developed for SPI for use in direct slicing of CAD models. While a major proportion of the direct slicing strategies employ the “marching” procedure involving determination of “critical points,” the proposed method utilizes the evaluation of “roots” of a surface in a global manner to determine the intersection points with proper connectivity. Hence, it is effective in reducing the computation time and is simple but generic in approach. Although Bezier and B‐spline surfaces are used as the representative cases, the algorithm can be extended for any parametric surface for direct slicing.

In adaptive slicing, the number of layers is drastically reduced by using sloping layer walls. For both vertical (2.5D slices) and sloping (ruled slices) outer walls, the strategies for determining slice height generally consider a number of vertical sections along the contour of a slice. Surface deviation error is calculated at these sections and slice height subsequently determined. Instead, a method is proposed which calculates error at every part of the surface. This method approximates the outer wall between two successive contours by a series of taut cubic spline patches. It is proposed that the deviation between such a patch and the actual surface is a better and more exhaustive estimate of surface error. Results show that the predicted number of slices is slightly higher than that predicted by existing methods for sloping layer walls.