Fiber Diameter Measurements Research Articles

Computer‐assisted image analysis for the measurement of wool follicle density and fibre diameter in skin sections

Historically, wool follicle density and fibre diameter have been measured in skin sections using a projection microscope. The aim of this study was to assess the use of computer‐assisted image analysis (IA) for measuring follicle density and fibre diameter from skin sections. Shrinkage correction factors, primary, secondary, and total follicle densities, and fibre diameter measurements, determined manually (M) by projection microscope and by IA, were compared to assess the differences between the methods. The repeatability of sample and field measurements and operator variation were determined for the IA method. IA and M measurements compared favourably with the exception of the correction factor and the sample repeatability measurement of primary follicle density. The results of this study indicate that IA measurement of follicle density and fibre diameter is both fast and comparable to the manual method, though it is essential to use skilfully prepared preparations.

The effect of nutrition on fibre growth in the alpaca

AbstractTwelve adult male alpacas were given either 0·67 (low) or 2·0 (high) × assumed maintenance requirements for a period of 6 weeks after which time each was transferred to the alternative level of nutrition for a further 6 weeks. Fibre samples were taken from two 10-cm2 areas on the mid-side position of each animal at 2, 6, 8 and 12 weeks, and measurements of fibre weight, yield (clean fibre weight/raw fibre weight), fibre diameter and fibre length made on the samples collected at weeks 6 and 12. The higher level of feeding resulted in higher clean fibre weight (low = 0·42 (s.e. 0·03); high = 0·53 (s.e. 0·04)mg/cm2 per day, P < 0·001) and fibre growth rate (low = 186 (s.e. 10); high = 223 (s.e. 14) yon/day, P < 0·05). Changes in yield (low = 0·917 (s.e. 0·006); high = 0·929 (s.e. 0·009)) and mean fibre diameter (low = 31·4 (s.e. 1·9); high = 32·1 (s.e. 1.6) \xm) were not statistically significant. Calculations showed that the increased weight of fibre attributed to the higher level of nutrition could be explained in terms of the observed increases in fibre-length and diameter but that, unlike the sheep in which the ratio fibre length: diameter remains relatively constant under varying nutritional regimes, the effect of nutrition in the alpaca has a proportionally larger effect on fibre length than on fibre diameter.

Optical and Scanning Electron Microscopic Study of the Effects of Charring on Indian Hemp (Apocynum cannabinumL.) Fibres

Indian hemp (Apocynum cannabinum L.) fibres were subjected to carbonization or charring by heating, varying the temperature (250° and 350°C), the ambient atmosphere (air and vacuum atmosphere) and the initial condition of the fibres (more and less exposed). Fibre diameter measurements showed that all carbonizing treatments resulted in a reduced fibre diameter. Observation using scanning electron microscopy indicated that higher carbonization temperatures and the presence of oxygen had a more severe effect on fibres and associated tissue. The initial condition of the fibre also had an effect on the consequences of carbonization, with more exposed fibres and fibres present as individuals being more severely carbonized than fibres protected by cambium and present in bundles.

On‐Line determination of density and crystallinity during melt spinning

AbstractThe density and crystallinity of polypropylene fiber were measured on the moving threadline during the melt spinning process. Heretofore, threadline densities have never been measured on‐line. These density measurements were accomplished by taking parallel, on‐line measurements of fiber diameter, fiber velocity, polymer mass flow rate fiber temperature, and fiber birefringence. Under certain spinning conditions, a distinct rise in density occurs along the threadline. This rise in density corresponds well with the rise in crystallinity as measured by birefringence.

Fresnel diffraction from curved fiber snippets with application to fiber diameter measurement

Fiber curvature is examined for its effect on apparent measured fiber diameter in a double-diffraction-based instrument that is in widespread use in the wool industry. The development uses a two-dimensional Fresnel diffraction model. The magnitude of the effect is studied for 2-mm-long snippets of various diameters from 8 to 50 µm and with radii of curvature of 1 m (straight), 600 µm, 280 µm, 200 µm, and 160 µm. The two-dimensional Fresnel model gives rise to deeply nested vector integrations that make computations with a straightforward approach exceedingly time consuming and impractical. A number of simplifying techniques are used to facilitate and speed up the numerical computations, thereby permitting investigations to be carried out on a personal computer.

Measurement of cashmere yield and mean fibre diameter using the optical fibre diameter analyser

A new technique was developed to measure the yield and mean fibre diameter of cashmere. The fibre diameter distribution of 2-mm snippets measured by the Optical Fibre Diameter Analyser (OFDA) was used to calculate cashmere yield of a goat fleece without dehairing. The total volume of fibres <35 and >35 �m was then calculated from the diameter distribution, and from this it was possible to predict the cashmere yield of 6 standards ranging from 10 to 60% yield (r2 = 0.98, n = 30). In addition, the Shirley Analyser was compared with the OFDA technique for measuring cashmere yield (r2 = 0.59, n = 110). OFDA estimates of cashmere yield were on average 10% higher (standard deviation � 7%) than those of the Shirley Analyser, indicating poor agreement between the 2 techniques. This is likely to be due to the Shirley Analyser and OFDA estimates of cashmere yield being affected by different fibre properties of the fleeces. There was good agreement between the Fibre Diameter Analyser (FDA) and the OFDA for measuring mean fibre diameter (MFD) of dehaired cashmere samples (r2 = 0.97, n = 108). There was also a good agreement in estimates of cashmere MFD between whole fleece and dehaired cashmere samples measured by the OFDA (r2 = 0.97, n = 77). Calculation of cashmere yield and down MFD by the OFDA has shown it to be accurate for measuring standard samples, and as precise as the Shirley Analyser. Therefore, the use of the OFDA is a potential low cost alternative to rank the value of cashmere goats for breeding.

Fiber-image Analysis Part I: Fiber-image Enhancement

This is the first paper in a series of puhlications on flber-image analysis. Image-analysis technology provides a new means of automatic measurement of fiber length, diameter, color, and other properties. This paper concerns the adaptation of image-processing techniques for enhancing fiber images, including background-leveling, valley-mapping and watershed segmentation, boundary extraction, and skeletonization. Specific attention is given to describing changes in the algorithms made for improving accuracy and efficiency. The implementation of the algorithms is explained with actual fiber images. These image-enhancement techniques are essential for a reliable and accurate fiber-measurement system.

Evaluation of the optical fibre diameter analyser (OFDA) for measuring fiber diameter parameters of sheep and goats.

The Optical Fibre Diameter Analyser (OFDA) instrument is based on automatic image analysis technology and was recently introduced to provide a rapid, accurate measurement of average fiber diameter (AFD) and diameter distribution (SD) of textile fibers. Experiments were conducted with wool and mohair in various physical forms (top, core, and staple) to compare results produced by the OFDA with two other methods of determining fiber diameter parameters: the standard projection microscope (PM) method as described by the American Society for Testing and Materials (ASTM) and the Peyer Texlab FDA 200 System (FDA200). The results show that the OFDA fiber diameter measurements were very closely related to PM measurements, and the OFDA partially overcame one shortcoming of the FDA200, overestimation of SD. The results suggest that the OFDA is a promising system for rapid and accurate evaluation of fiber diameter and its distribution.

The development of the diaphragm in infants with sudden infant death syndrome

The morphological development of the skeletal muscle of the diaphragm was studied in normal controls and cases of sudden infant death syndrome (SIDS). Measurements of fiber diameter indicated that the SIDS population had significantly larger diameters for type 1 and type 2 fibers than the control population. The ratio of type 1 to type 2 fibers was found to remain significantly depressed with increasing age in the SIDS population compared with the control population, where it increased linearly to values between 0.8 and 1.2 after 10 months of age. These results suggest an abnormality in the development of the diaphragm of SIDS victims, although its exact nature remains to be determined.

Fiber diameter measurement of bulk man-made vitreous fiber

This procedure describes a method for determining the distribution of fiber diameters of man-made vitreous fibers (MMVF) in bulk products by optical microscopy. Although some very thin fibers may be present in a typical bulk MMVF sample, repeated studies have shown that optical techniques provide a satisfactory method for the determination of the fiber diameter distribution for any product with an anticipated mean fiber diamter of 1 μm or larger. This procedure is applicable for the determination of the diamter distribution of bulk samples only and is not intended for use with aerosol samples where the number of particles is an important consideration.

A model to estimate the economic value of using individual fleece fibre diameter measurements to class wool

Woolclassing in Australia traditionally relies upon a subjective visual appraisal of fleeces. A new approach to woolclassing, termed objective classing, has been adopted by some woolgrowers. In objective classing, fine and broad lines of wool are created using pre-measured individual fibre diameter data, rather than the subjective appraisal of the classer. This paper describes a computer model that estimates the clip preparation that maximises net return, and the expected economic value of objective classing. The effect of mean and standard deviations of fibre diameter, test precision, wool market conditions, and clip preparation on expected economic value was examined. Results indicated that objective classing was not of universal benefit. The value of objective classing was greatest for fine wool, particularly if sold when there was a large premium for fine wool and a high market indicator. The economic value of objective classing rapidly reduced if the standard deviation of the fibre diameter test fell below 0·5 μm, or if the clip was sub-optimally prepared. In many circumstances objective classing was not economically justifiable, unless the fibre diameter measurements were used for other purposes, such as a genetic improvement programme.

Effect of intraperitoneal administration of lysine and methionine on mohair yield and quality in Angora goats.

Eight mature Angora wethers (average BW 47.2 kg) were used in a 4 x 4 replicated Latin square design to evaluate responses to intraperitoneal (IP) administration of amino acids. The IP treatments consisted of saline (Control), methionine 1 g/d (Met), lysine 2 g/d (Lys), and methionine + lysine (Met + Lys). The amino acids dissolved in Control were infused continuously for the first 14 d of each 28-d period using peristaltic infusion pumps. Average d-28 grease and clean mohair yields (grams/100 square centimeters), and fiber diameter (micrometers) and length (centimeters) measurements during Control administration were 8.8, 7.6, 40, and 2.3, respectively. Mean clean mohair yield and fiber diameter increased by 5.3% (P less than .039) and 2.5% (P less than .067), respectively, with Met administration but were decreased by 9.2% (P less than .033) and 3.8% (P less than .001), respectively, by Lys administration; however, mean fiber length was increased (P less than .014) 21.7% by Lys infusion. The goats did not exhibit increased grease (P greater than .939) and clean (P greater than .477) mohair yields and fiber diameter (P greater than .619) when treated with Met+Lys. A N balance trial was conducted during d 10 through 14 of each period. Total retained N (grams per day) during Control administration was 18.4 and 24% greater than Met (P greater than .281) and Lys (P less than .061), respectively. When expressed as a proportion of N intake, retained N was lowest (P less than .127) in the Lys infusion group. Jugular blood ammonia N and plasma glucose and total protein concentrations were not affected (P greater than .10) by treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

A quantitative study of satellite cells and myonuclei in stretched avian slow tonic muscle.

Satellite cell frequency was assessed in control and stretched anterior latissimus dorsi (ALD) muscles of adult quail. A weight equal to 10% of body mass was attached to one wing for time intervals ranging from 1-30 days. The contralateral ALD served as the intra-animal control. Satellite cell frequency, expressed as a percentage of total myofiber nuclei within the basal lamina, was determined in eight control and stretched ALD muscles, that had been weighted for 5, 7, or 10 days. Satellite cell frequency was determined in 584 control and 473 stretched fibers and was not different in the control or stretched ALD muscles (15.6 +/- 2.3%, 16.7 +/- 6.1%, respectively). The number of myofiber nuclei (myonuclei and satellite cell nuclei) was examined in whole fiber segments from control and stretched ALD muscles of 27 adult quail. Nuclear frequency was determined in 500 control and 1,200 stretched fiber segments. Fiber volume was calculated from fiber length and diameter measurements. Nuclear number normalized to 10,000 microns 3 fiber volume was correlated to fiber cross-sectional area (P less than 0.0001). Fibers with cross-sectional areas less than 500 microns 2 had a greater nuclear to fiber volume ratio compared to fibers with areas greater than 500 microns 2. The nuclear-to-cytoplasmic ratio was not constant in smaller fibers. Nuclear density decreased as fiber cross-sectional area increased up to 500 microns 2. Fibers with cross-sectional areas greater than 500 microns 2 demonstrated a constant nuclear-to-cytoplasmic ratio. The results demonstrate that absolute nuclear number increased to maintain a constant nuclear-to-cytoplasmic ratio in the stretched hypertrophied fibers. Daughter cells originating from activated satellite cells may have contributed to the myonuclear population to maintain a constant nuclear-to-cytoplasmic ratio in the hypertrophied fibers of the adult quail.

Diameter measurement of small fibres: laser diffraction and scanning electron microscopy technique results do not differ systematically

In order to determine the mechanical properties of small fibres, such as the tensile strength and modulus, or to determine the interface properties between fibre and matrix in composites, an accurate and reliable fibre diameter measurement method is required. Due to the limitation of the wavelength of light, fibre diameters measured optically with a microscope are often not sufficiently accurate. Scanning electron microscopy (SEM) measurement can yield exact results, but is very time-consuming. Therefore, a practical alternative is the use of the laser diffraction (LD) method [1]. However, the question is whether the results obtained from this fast method are in accordance with the exact SEM results. Li and Tietz [2] found a systematic difference between fibre diameters measured by SEM and diameters measured using the LD method. They obtained a 5% larger value from the LD method and proposed an error correction. This result could not be confirmed by our investigation. The principles of our LD equipment are illustrated in Figs 1 and 2. The beam diameter of the low-power (0.8 mW) HeNe laser used was reduced by two lenses. The first (convex) lens with a 60 mm focal length focused the laser beam and the second (concave) lens with a 40 mm focal length reparallelized the beam. With this two-lens layout the diameter of the beam could be reduced up to a quarter of the initial incident diameter. Furthermore, a polarization filter and a blind were used to suppress reflections from the lenses. The fibre sample was adjusted perpendicular to the laser beam. The interference pattern was recorded by a photodiode on a sledge simply driven by an analogue y t writer. The direct coupling of the moving diode to the writer avoided transmission faults of the interference pattern. The fibre diameter, d, could be calculated from the laser diffraction equation

Projection-microscope Measurements and Sheppard's Correction

An investigation is reported in which computer-simulation studies were used to assess the need to apply corrections to the estimates of mean and variance from grouped data such as are obtained when fibre-diameter measurements are made by projection microscope; these estimates are usually regarded as biased. The studies reported here confirm that this so but that the bias is variable, apparently at random.

Secondary follicle development in Australian cashmere goats

Development of secondary hair follicles was studied in three sets of twin goat kids, from two weeks to fourteen months of age, in order to determine the age at which full cashmere production potential has been reached. Kids achieved maximum secondary follicle development (determined from monthly skin secondary to primary follicle (S:P) ratio measurements) at about 20 weeks after birth, at which time cashmere percentage, determined from fibre samples, was found to be a good approximation of the proportion of secondary follicles of these animals born in October (spring). No difference in S:P ratio or rate of secondary follicle maturity was found between male and female kids. It is proposed that S:P ratio determinations on skin biopsy samples would not be significantly more useful than fibre diameter measurements taken at the same time. If S:P ratio measurements are to be made, samples should be taken during the summer months when the follicles are active, in order to avoid difficulties encountered with such measurements during the resting or shedding stage. Fibre diameter was greatest during summer, narrowing again in winter immediately before shedding. It is suggested that fibre samples taken between the ages of 20 and 40 weeks of age may be used to select animals for production purposes, at least for kids born in spring.

Improved accuracy of the laser diffraction technique for diameter measurement of small fibres

The accuracy of a laser diffraction technique has been improved for small fibre diameter measurement by a calibration with SEM-measured internal standards. The calibration showed that the laser diameter is about 5% larger than the corresponding SEM diameter. After correction for systematic error via accurate calibration, the laser technique was found to be fast and capable of attaining a diameter measurement accuracy of 0.1μm.

Quantitative and qualitative morphology of equine peripheral nerve: teased fibre studies

Single teased fibre studies were made on samples of the lateral palmar nerve from 16 horses of mixed age and size which had no evidence of neuromuscular disease. Significant proportions of abnormal fibres indicative of axonal degeneration/regeneration and demyelination/remyelination were identified. Measurements of internodal length and fibre diameter were made. Internodal length was shown to be related to fibre diameter, changes in this relationship being mainly influenced by the incidence of abnormal fibres rather than by the age of the horse. Information about the incidence of abnormal fibres in normal horses is required if findings in biopsy material are to be interpreted correctly.

Fiber diameter measurements and their calibration

Seeks to establish a high level of confidence in fiber cladding diameter measurement by the use of three methods: white light interferometry, mechanical contact, and image inverting microscopy. Calibration with transfer fibers is considered unattractive because of the difficulty of maintaining the calibrated cleaved end. The uncertainties involved in calibrating other methods are investigated, namely image shear, grey scale digitization, and refracted near field, using chromium on glass circular patterns or lines. Their use is found to give consistent results with uncertainties not exceeding +or-0.15 mu m. Experimental arrangements are discussed. There are some sources of measurement error, but these can be overcome so that measurements of fiber diameter with an uncertainty of less than +or-0.15 mu m look feasible using chromium on glass calibration standards.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

An on-line fiber drawing tension and diameter measurement device

A noncontact online drawing tension meter is described. This meter measures both the drawing tension and fiber diameter during the fiber drawing process. Experimental results show that this meter functions satisfactorily in all aspects of testing. The knowledge of online drawing tension not only helps in the manufacture of fibers with low surface tensile stress, but it also gives information about furnace temperature change and the viscosity of the glass at the neck-down region. >