Journal articles on the topic 'Leather defects'

Leather is one of the important export commodities in Ethiopia. However, itsquality and physical characteristics are affected by diseases, handling and storage problems. A cross-sectional study was conducted to identify major hide and skin defects and assess their effect on quality grades and physical characteristics of crust leather. A total of 6530 hides and skins were inspected at Sheba Tannery and Leather Industry Private Limited Company (PLC) through standard operative procedures. For tests on physical characteristics of crust leather, top 6 defects of skin and hide were identified thereby each 5-crust leather per defect were evaluated by standard experiments for determining testing tensile strength, tear strength and percentage elongation at break. The overall hide and skin rejection was 32.7%. The rejection in wet blue hide (23.5%) was higher than for wet blue salted and dry goatskins (5.1%) and pickled sheepskins (4.1%). Scratch (20.5%), Wound (14.6%) and Cockle (12.7%), were the most common pre-slaughter skin and hide defects found in wet blue hide, goatskin and pickled sheepskin, respectively. Knife cut with proportion of 21.1%, 17.5% and 4.5% respectively in wet blue hide, goatskin and pickled sheepskin was the major slaughter defect. Putrefaction was of the most common post-slaughter defect in wet blue hide (5.3 %), pickled sheepskin (1.6%) and goatskin (2.7%). Among the identified major defects, statistically significant reduction (p<0.05) were noted in tensile strength, tear strength and percent elongation of the crust leather. Major skin and hide defects lead to considerable economical losses through reducing quality and physical performance characteristics of crust leather. Hence, innovative leather grade correction technologies are timely important. Keywords: Defects; hide; physical characteristics; quality; skin

Detection of defects in a typical leather surface is a difficult task due to the complex, non-homogenous and random nature of texture pattern. This paper presents a texture analysis based leather defect identification approach using a neural network classification of defective and non-defective leather. In this work, Gray Level Co-occurrence Matrix (GLCM) is used for extracting different statistical texture features of defective and non-defective leather. Based on the labelled data set of texture features, perceptron neural network classifier is trained for defect identification. Five commonly occurring leather defects such as folding marks, grain off, growth marks, loose grain and pin holes were detected and the classification results of perceptron network are presented. Proposed method was tested for the image library of 1232 leather samples and the accuracy of classification for the defect detection using confusion matrix is found to be 94.2%. Proposed method can be implemented in the industrial environment for the automation of leather inspection process.

The leather productions are produced rapidly in people’s living, the productions’ quality is required stricter. Leather must be detected include leather plainness; leather surface defects and the density of leather before they are produced to be productions.. The most important aspect is the surface defects; the defects’ location, size and quantity should be confirmed. One of the most important steps of leather defects detection is leather image segmentation so as to extract leather defects. Gray level co-occurrence matrix is used to extract a lot of leather surface texture feature, the method of optimized Fuzzy C-means is used to segment leather image in the article. The optimized Fuzzy C-means add the spatial information; the precision of segmentation is improved. The image needs to be treated use morphological approach after it is segmented. As a result, the defective areas are separated from non-defective areas successfully.

Article, pickle, and wet blue leather defects used for this study were fromthe Balai Besar Karet college, Kulit dan Plastik, D.I Yogyakarta (BBKKP YK), Indonesia. Meanwhile, the microorganisms in leather defects were grown in vitro at A-minimal mineral (MM) and B-lowest (1/200 v/v) nutrient media. A nitrogen source of 2% Sigma-Aldrich bovine gelatine was added to each medium. Furthermore, 1cm2 of each leather defect was sliced and immersed into the in vitro media for 7 days in an open-air rotary incubation with ambient temperature at 28° C to 30° C. The first or conventional method was the rubbing of ose cotton into the solid media, while the second isolation method was the centrifugationof liquid growth medium at 15.1G for 20 minutes. Moreover, the four microbial isolates were fromglossy yellow colonies A and B as wel as white colonies. These colonies were incubated at 38° C and the four microbes produce proteases after growing for at least 7days in liquid media and 24 hours less in solid media. The protease test produced gases on the pickle leather defects using a test tubeglass of 0.8cmdiameter and 15cmlong. Therefore, the chemical tanning process on leather defects creates a unique ecosystem of microorganisms as collagen proteins change and become thekeyto their growth.

The visual inspection system was developed for defects detection on leather surfaces, which is an important component of automatic CAD/CAM cutting systems. The main functions of the system are quality control and raw material cutting. An efficient algorithm, which combines multiresolution approach, energy and entropy matrices, is presented for detection of defects embedded in leather surface images. A wavelet band selection procedure was developed to automatically determine the number of resolution levels and decompose subimages for the best discrimination of defects and removals of repetitive texture patterns in the image. An adaptive binary thresholding is then used to separate the defective regions from the uniform gray-level background in the restored image. The proposed methodology is able to efficiently detect several types of defects that current approaches cannot detect, and is fast enough to be used for real-time leather inspection.

The final appearance and technical features of leather are determined by the finishing stages of leather processing, which comprise a range of operations and treatments. It is desirable to reduce or mitigate the existing defects in the original hide, to modify the surface properties of the leather and to improve leather properties under conditions of use. In the final stages of leather processing, many products are applied to form a protective coating. These coatings include resins such as polyacrylates, polyurethanes and casein. In this context, this work aims to describe aspects of the films formed with commercial polymeric resins used industrially in leather finishing. A methodology is proposed for characterizing the properties of polymeric film layers and their correlation with the material composition, through a parameter survey and physical tests.

Abstract. CV. X is a company engaged in the leather industry that manufactures wallets, bags and key chains. The company experienced a decrease in sales volume due to a decrease in product quality from defective products in the company. Leather bags have an average percentage of disability of 2.39% in 2017-2018 from the company's disability limit of 2%. The existence of these defective products requires companies to improve product quality to reduce the occurrence of defects. The method used to solve the problems that are being faced by the company is the Seven Tools Quality Control method to identify the causes of product defects, while the Rezhenija Izobretatelskih Zadach (TRIZ) method is used to design a product quality improvement plan. The result of data processing which becomes the main priority is defect cutting. The causes of cutting defects include decreased work concentration, inadequate workers, poor physical condition, no machine maintenance, blunt cutting machines, high cutting machine use intensity, work environment, hot room temperature, lack of work space lighting. All causes of product defects are designed to improve the quality of leather bag products by creating visual controls, forms for worker health, cutting knife replacement machines, installing air conditioners, and adding lights to the sewing machine. Abstrak. CV. X merupakan perusahaan yang bergerak di bidang industri kulit yang memproduksi dompet, tas, dan gantungan kunci. Perusahaan mengalami penurunan volume penjualan yang disebabkan karena adanya penurunan kualitas produk dari produk cacat di perusahaan. Tas kulit memiliki rata-rata persentase kecacatan sebesar 2,39% pada tahun 2017-2018 dari batas kecatatan yang ditetapkan perusahaan sebesar 2%. Adanya produk cacat tersebut mengharuskan perusahaan melakukan perbaikan kualitas produk untuk mengurangi terjadinya kecacatan. Metode yang digunakan untuk menyelesaikan permasalahan yang sedang dihadapi oleh perusahaan yaitu metode Seven Tools Quality Control untuk mengidentifikasi penyebab terjadinya kecacatan produk, sedangkan metode Teorija Rezhenija Izobretatelskih Zadach (TRIZ) digunakan untuk membuat rancangan perbaikan kualitas produk. Hasil pengolahan data yang menjadi prioritas utama yaitu cacat potong. Penyebab cacat potong diantaranya yaitu konsentrasi kerja menurun, pekerja kurang hati-hati kondisi fisik kurang baik, tidak ada perawatan mesin, mesin potong tumpul, intesitas penggunaan mesin potong tinggi, lingkungan kerja, suhu ruangan panas, pencahayaan ruang kerja kurang. Semua penyebab cacat produk dibuat rancangan perbaikan untuk meningkatkan kembali kualitas produk tas kulit dengan membuat visual control, form untuk kesehatan pekerja, mesin penggantian pisau potong, pemasangan AC, serta penambahan lampu pada meisn jahit.

Looseness is a defect found in leather that reduces its quality by causing a wrinkly appearance in the finished product, resulting in a reduction in its value. Earlier studies on loose leather using microscopy and Raman spectroscopy reported a change in the collagen structure of loose leather. In this study, proteomics was used to investigate the possible molecular causes of looseness in the raw material, the first time such a study has been carried out. Proteins extracted from two regions of raw hide using two different methods were analysed; those taken from the distal axilla, an area prone to looseness, and those taken from the backbone which is less prone to looseness. Analyses using 1DE-LC-MS/MS showed that although the overall collagen concentration was similar in both areas of the hide, the distribution of the different types of collagen differed. Specifically, concentrations of type I collagen, and the collagen-associated proteoglycan decorin were lower in samples taken from the distal axilla, symptomatic of a collagen network with excess space seen for these samples using confocal microscopy. This study suggests a possible link between the molecular components of raw cattle hide and looseness and more importantly between the molecular components of skin and skin defects. There is therefore potential to develop biomarkers for looseness which will enable early preventative action.

Background: Authors of this article have made a comparative identificational description of artificial leather damage caused by air gun pistol pellets with different head end forms. Aim: This study aimed to provide a comparative identification characteristic of injuries caused by shots from an air pistol MP-53 M on artificial leather with a raised surface and a textile net glued to the wrong side at different angles and from different distances by bullets with different head end shapes (hemispherical, flat round, and conical). Used: Air pistol MP-53M, bullets with different head end shape, a fragment of black artificial leather with an embossed surface, and a textile mesh glued to the wrong side. Shots were fired at close range, 50 and 100 cm at angles of 30, 45, 60, and 90. The prevailing forms of damage (defects) of artificial skin, characteristic of bullets with a hemispherical, conical, and flat rounded head end, dependence of the form of damage (defect) on the distance of the shot, and the angle of entry of the bullet into the material. Conclusion: A comparative study showed that the form of damage to the material depends on the head end shape of bullets. Moreover, intragroup differences were found in the damage due to the distance of the shot and angle of entry of the bullet into the material in groups of bullets with the same head end shape.

Roughing operation is used to improve the adhesive properties of footwear upper to footwear bottom polyurethane compositions in the manufacture of special purpose footwear with an upper made of genuine leather by the injection molding method of attachment. Roughing operation is an operation of coating removal and partial removal of the front layer from the protracted edge of footwear upper workpiece. This operation has a disadvantage, it often causes technological defects. A method for increasing the adhesive properties of genuine leather special purpose footwear upper workpiece with a front layer by means of non-equilibrium low temperature plasma modification and technological scheme that allows this operation to be integrated into the production process are considered in the article.

The results of studies of morphometric parameters of the yak skin of the Altai population are presented. It was found that the yield of paired skins is on average from 5,5 % in yak bulls of 18 months to 6.3 and 8,3 % in yak bulls and yak cows, respectively. The measurements of the length and width of the skin are almost the same or the length is slightly inferior to the width, which is due to the fact that the body of the yak is shorter than that of the local cattle. When examining the raw leather, all the skins were without any defects in life. The weight of the skins of yak-bulls of the Altai population was 34,3±1,2 kg and they are classified as heavy, the skins of yak-bulls at the age of 18 months correspond to the category “half-skin” (from 10 to 13 kg), and the weight of the skins of yak cows of the Altai population-”yalovka” is suitable for the average weight category - from 17 to 25 kg. The thickness of the skins of Yak bulls on the last edge was 7.1 mm, which is higher than the requirements of GOST by 2.3 mm, in bull calves the excess was 3.1 mm, in yak cows-1.1 mm. According to their morphometric characteristics, the skins of Altai yaks meet the requirements of GOST 28425-90. The raw materials are leather and refer to the raw leather intended for the production of leather for the bottom of shoes and shoe leather. They can also be widely used by the local population as raw materials for the production of saddlery and technical leather.

PT XYZ is a company engaged in leather tanning since 1966. The skin used by PT XYZ is sheep skin and goat skin, each of which has a composition of 50%. This study aims to analyze product defects in the process of shaving (tanning) by using statistical quality control and knowing the factors that cause product defects using Ishikwa diagrams. The results showed that there were three types of disabilities, namely tear, lorek, and thinness. By using the control chart p (p-chart) there are 5 out of control data observations with prioritization of repairs that must be done first is the type of tear, thinness, and finally lorek which analyzed the causes of product defects using Ishikawa diagram.

The leather industry is one of the heavy-polluting and hazardous industries that is creating toxic and harmful effects on the environment and human health by producing waste chemicals, tannery effluents, and various pollutants. Moreover, Tanning is the required stage to convert raw skin to durable and sustainable skin but most of the chemicals, salts, organic and inorganic toxic pollutants are produced. In commercial practices, Chrome tanning is the highly employed approach that uses a large number of basic chromium salts that becomes the major source of chromium pollutant in the environment. Chromium salt is not only harmful to the environment and ecology but also harms the human body such as causing respiratory problems, infertility and birth defects, skin and lung cancer of the workers. This article has presented two alternatives eco-friendly greener approaches of chrome tanning and waste management technique to reduce the toxic effect on the environment and human health. Firstly, to get rid of these harmful effects, the possible remedy of environmental and human health problems may be considered the vegetable tanning process. Vegetable tanning uses tannins (a class of polyphenol astringent chemicals), which occur naturally in the bark and leaves of many plants. Secondly, chrome tanning associate with ultrasound having a frequency range of 20–100 kHz is commonly employed for enhancing the physical processes and for performing chemical reactions. The basic principle associated with the process is an ultrasonic cavitation in dissolved media. Ultrasound decreases the consumption of conventional water and chemicals because it can also function as a physical activator resulting reduction in environmental pollution which is a prime concern nowadays to approach greener leather technology and eco-friendly leather processing. Furthermore, the possible waste management technique of chrome tanning helps to prevent pollution and ensure eco-friendly green technology of leather processing. Therefore, vegetable tanning and chrome tanning associated with ultrasound having proper waste management will be the viable and sustainable options for the tanners in the forthcoming future.

Tanned leather is an output from complex processes called tanning. Leather tanning is an important step that used to protect the fiber or protein structure of animal’s skin. Another reason of tanning process is to prevent the animal’s skin from any defect or rot. After the tanning is complete, the leather can be applied to produce a wide variety of leather products. Thus, the leather prices usually more expensive because it takes longer time in process. Another way to get cheaper price is make non-animal leather that usually known as synthetic or imitation leather. The purpose of this paper is to classify the tanned leather and synthetic leather by using Convolutional Neural Network. The tanned leather consist of cow, goat and sheep leathers. The proposed method will classify into four class, they are cow, goat, sheep and synthetic leathers. In each class consist of 160 images with 448x448 pixels size as the input data. With CNN method, this research shows a good result for the accuracy about 92.1%.

A series of studies investigated the toxicities of tannery-derived complex mixtures, i.e. vegetable tannin (VT) from Acacia sp. or phenol-based synthetic tannin (ST), and wastewater from tannin-based vs. chromium-based tanneries. Toxicity was evaluated by multiple bioassays including developmental defects and loss of fertilization rate in sea urchin embryos and sperm ( Paracentrotus lividus and Sphaerechinus granularis), and algal growth inhibition ( Dunaliella tertiolecta and Selenastrum capricornutum). Both VT and ST water extracts resulted in hormetic effects at concentrations ranging 0.1 to 0.3%, and toxicity at levels ≥1%, both in sea urchin embryo and sperm, and in algal growth bioassays. When comparing tannin-based tannery wastewater (TTW) vs. chromium-based tannery effluent (CTE), a hormesis to toxicity trend was observed for TTW both in terms of developmental and fertilization toxicity in sea urchins, and in algal growth inhibition, with hormetic effects at 0.1 to 0.2% TTW, and toxicity at TTW levels ≥1%. Unlike TTW, CTE showed a monotonic toxicity increase from the lowest tested level (0.1%) and CTE toxicity at higher levels was significantly more severe than TTW-induced toxicity. The results support the view that leather production utilizing tannins might be regarded as a more environmentally friendly procedure than chromium-based tanning process.

Dyes are colored organic compounds that are used to pigment fiber or other materials. Dyes are mainly calssified into natural and synthetic dyes in terms of the origin. Natural dyes include animal dyes, plant dyes and mineral dyes with such defects as incomplete chromatogram, inconvenient use and color fading, and thus have been gradually eliminated. In 1856, the 18-year-old young British scientist Perkin successfully invented the world's first synthetic dyes. He built his own factory and industrialized synthetic dye production. Over 100 years since then, dye industry has undergone rapid development, and by 2001 synthetic dyes already have been up to nearly 10,000 varieties. In 2004, the output of total dyes in the world has reached 900,000 tons. Synthetic dyes are used comprehensively, not only to dye synthetic fibers, but also natural fibesr, fur, leather and man-made fibers.

The effect of ostrich feather lice (Struthiolipeurus struthionis) on productivity and leather quality was investigated in the light of louse-related skin damage on other livestock species that seems similar to defects, called pitting, seen on ostrich skins. The occurrence and spread of feather lice on ostriches were also studied. Natural infestation of louse-free ostriches within a group mixed with louse-infested ostriches was achieved within 6 months. Lousiness was determined by visual counts on the body and feathers of the ostriches on five locations. There was a relatively low correlation between the number of lice observed on the live ostriches and the actual number of lice extracted from harvested wing feathers. However, it was demonstrated that lice obtained from feathers increased at a rate of 3.29 (s.e. = 1.34) lice per 100 g of feathers for an increase of one louse observed on the live birds in the paddock (R2 = 0.23). Treatment with synthetic pyrethroid insecticides eradicated all lice. Louse infestation had no significant influence on growth or slaughter traits, while no causal relationship between louse infestation and pitting damage on the processed ostrich skins could be demonstrated.

Abstract Collagen, a biopolymer finds its application in the preparation of pharmaceutical products that are used in wound management, ophthalmic, orthopaedic and oral surgeries. This wide applicability is due its special properties such as biodegradability, biocompatibility, easy availability and high versatility. Collagen is isolated from various sources such as bovine skin, fish skin, chicken skin, skin waste of marine organisms, solid wastes of leather industry, short tendons of slaughtered cattle and bone. The isolated collagen from biological wastes is found to be cost effective due to the adaptation of simple methods for its isolation when compared with other commercially available biological macromolecules. The functional groups such as amino and carboxylic acid present in collagen helps in its modification that suits for various end uses which include wound healing, ophthalmic defects, drug delivery and tissue engineering applications. These beneficial properties impart uniqueness to collagen molecule among the available bio molecules.

Collagen is one of the most used biomaterials for bone defects repair, proving good results in tissue reconstruction research, and also its features recommend it as a very attractive drug delivery scaffold for local treatment of the affected osseous tissue. The inflammatory response is a common reaction that occurs in bone disease, the topical administration of anti-inflammatory drugs (NSAIDs) representing a reliable strategy to overcome this issue. The purpose of this paper was the physical-chemical and biopharmaceutical evaluation of some spongious matrices consisting of collagen as release support and niflumic acid as drug NSAID model, usable in bone tissue regeneration. Type I fibrillar collagen gel (2.4% w/w, 3.5 pH) was extracted from calf hide by the technology currently used in Collagen Department of Division Leather and Footwear Research Institute. The collagen sponges were obtained by freeze-drying of gels adjusted at 1% and 7.3 pH, with different dextran (0; 10 and 20%) and MgO (0; 30 and 60%) concentrations (reported to dry collagen), with 0.5% and without niflumic acid (NA) (reported to gel) and the same amount of glutaraldehyde (0.5% reported to collagen dry substance). The sponges were evaluated through water absorption, FT-IR spectroscopy and optical microscopy. In vitro NA release from the designed sponges was carried out using a sandwich device adapted to a dissolution equipment. Power law kinetic model was applied to explain drug release from the tested formulations. The NA release from collagen sponges showed a non-Fickian transport mechanism. The addition in different concentrations of dextran and MgO leads to more compact structures and improves stability of collagenic matrices. Our results showed that the designed support could be adequate for treating the inflammation associated with a bone defect in orthopedic surgery.

Data regarding the prevalence of skin diseases reducing the market value of skins and hides and ultimately refined leather were not available in Pakistan. The current study was conducted in the hide/skin markets and abattoirs of Lahore and Faisalabad and tanneries of Sheikhupura, Kasur and Sialkot. The record of various skin diseases and conditions damaging the skin/hide of cattle, goat and sheep was made. Lesions, extent and type of damage were recorded. A total of 21,671 skins / hides were examined out of which 3918 of skins and 600 hides were examined at the abattoirs of Lahore and Faisalabad, 6784 Skins and 1399 hides at hide markets and 8091 skins and 879 hides at tanneries. Out of total 21,671 skins / hides, 66.12% were normal and 33.88% were having some sort of damage. The data were gathered on questionnaire sheets. The prevalence of skin diseases was assessed through Strata V.9 software program. The correlation of the disease and area was analyzed by the chi-square. The prevalence of various diseases and damages due to mal-management in sheep, goats and cattle has been discussed in detail. The damages in goat skins were significantly less as compared with cattle and sheep. However, the type of defects and severity varied amongst various ruminants studied. The most common damages observed, overall in all species studied were atrophy of skin (Thin skin) 6.38%, followed in descending order observed was lesions of wounds 4.94%, old lesions of pox 4.82%, flaying cuts 3.17%, tick infestation 3.08%, lesions caused by mites infestation 2.45%, scratches 2.33%, lesions caused by warble fly larvae 1.47%, decomposition 1.32%, charr (fibrosis) 1.28%, ringworm infection 1.10%, extensive soiling by dung 0.84%, chronic abscesses 0.46%, and Lice infestation 0.17%.

Deep bite is the most common dental maxillary anomaly in the vertical plane, characterized by elongation of the dental alveolar part in the anterior segment and shortening in the lateral one. At the same time there are different, both the size of the jaws, and their ratio, as well as the position in the skull, which largely depends on the structure of the skull, which is congenital in each person from birth, that is genetically predetermined. The development and structure of the skull, as is known, affects not only genetic factors, but also teratogenic ones, that is, exogenous factors, namely: early loss of teeth, especially temporary, and untimely compensated defects of dentition; bad habits, general human health, the environment etc. All these should be taken into account when establishing the correct diagnosis, which is impossible to do without such objective x-ray methods as cephalometry. The analysis of cephalogram was carried out by A.M. Schwarz method, which included three main sections of the study: craniometric, gnatometric and prophylometric. In craniometric studies, the definition of the following parameters was defined, namely: N-Se length (distance from the bone "N" to "Se" - the middle of the entrance to the «Sella turcica»); the magnitude of the facial angle F (N-Se-N-A) formed by the plane N-Se and the faсial plane - NA; Inclination angle ∟І (∟Pn-SpP) formed by the nasal vertical - Pn and the palatal plane - SpP, which corresponds to the plane of the base of the upper jaw SpP; the corner of the Frankfurt line - ∟H; The angle of inclination of the occlusal plane - OcP to the nasal vertical - is Pn (∟Pn-Ocp) and the angle of the mandibular plane, that is, the plane of the base of the mandible - MP to the nasal vertical - ∟Pn (∟Pn-MP). The main task of craniometric measurements was to determine the individual genetically determined profile of the face in each particular patient with deep bite. Gnatometric measurements included determining the values of the following angles: basal ∟B (∟SpP-MP), that is, the angle of inclination of the plane of the body of the upper and lower jaw to each other; Lower jaw or gonial angle ∟Go (A-MP) Gnatometric studies also included the determination of jaw size: Mandible - the distance of the "OK" and the extension of the wingspan of the FrR; Maxilla - body "MT1" (in the plane of MP from the point "Go" to the intersection of the perpendicular, lowered from the most prominent point of the bone chin "Pgo", and the height of the branch - MT2. Profilometric studies included: determining the thickness of the soft tissues of the patient's face in the back area the nasal «n», the tray is «sna», the upper lip «ls», the lower lip «li» and the chin «pgo», the profile T, formed by the intersection of the tangent from the tray leather point «sna» to the most prominent leather point of the chin "Pgo" with the nose vertex "Pn", as well as the height of the part faccial - medium (from «n» - nasion to «sna» - pidnosovoyi) and lower (from «sna» to the lowest point of the chin «Me»).

As a novel polymer, polyurethane (PU) has been widely applied in leather, synthetic leather, and textiles due to its excellent overall performance. Nevertheless, conventional PU is flammable and its combustion is accompanied by severe melting and dripping, which then generates hazardous fumes and gases. This defect limits PU applications in various fields, including the leather industry. Hence, the development of environmentally friendly, flame-retardant PU is of great significance both theoretically and practically. Currently, phosphorus-nitrogen (P-N) reactive flame-retardant is a hot topic in the field of flame-retardant PU. Based on this, the preparation and flame-retardant mechanism of flame-retardant PU, as well as the current status of flame-retardant PU in the leather industry were reviewed.

Self-attracting walk (SATW) on non-uniform substrates has been investigated by Monte Carlo simulations. The non-uniform substrates are described by Leath percolation clusters with occupied probability p. p stands for the degree of non-uniformity, and takes on values in the range pc≲p ≤1 where pc is the threshold of percolation. For the case of strong attractive interaction u, p has little influence on the walk which is dominated by attractive interactions. Furthermore, in the case of small scales, the exponent ν of the mean end-to-end distance <R2(t)> versus time t is given by ν≃1/(ds+1), while the exponent k of visited sites versus t is given by k≃ds/(ds+1), where ds are the fractal dimensions of the substrates. For u ≃ 0, the walk reduces to the random walk on percolations with p in pc≲p≤1. Also, ν and k decrease sensitively with the reduction of p. It is found, the blocked sites in the substrates (i.e. defects) have much greater influence on the walk driven by thermal flunctuation than that dominated by the attractive interaction.

Scrutiny of intermittent leather is accepted through visual analysis on the natural material by an experienced individual based on many parameters which includes surface defects as a parameter. Such results comprising of base color, other than base color, share of regions, share of cutting area, share of cutting value, position wise length and position wise breadth will determine the value of the leather and surprisingly the result will vary form one experienced person to another. Hence, a new method for grouping of intermittent leather is proposed for a better or suitable decision making. Feature extraction technique, Grey Level Co-occurrence Matrix (GLCM) has been implemented to understand the features of color and area by extracting the texture features like Entropy, Energy, Contrast, Variance, Mean, Dissimilarity, Correlation and Homogeneity. A total of 428 intermittent leather imagesare used to understand the classification. The classifiers, Linear Discriminant Analysis (LDA) model and Support Vector Machine (SVM) are used to find out the accuracy. Further, linear discriminant model confirms 92% of accuracy over the support vector machine which is confirms 89.65% of accuracy. The proposed LDA model clearly shows that the approach is successful in classifying the variations among the defects and non-defects in intermittent leather images.

Assembly of Most composite components requires secondary machining operations, such as drilling. Various methods such as drilling by means of twist drills bits, laser beam and abrasive jet machining are used to drill these materials, and twist drill bit is considered to be the most inexpensive and most commonly used method. The present paper is an attempt to investigate the effect of feed rate and rotational speed of drill bit on delamination rate during drilling of a 1.4 mm thick Kevlar-epoxy composite sheet as well as the hole diameter error in this sheet. Kevlar fibers are widely used in composites that are utilized in the aerospace industry. 4 feed rate levels and 4 spindle speed levels were selected to conduct a full-factorial experiment and each experiment was repeated three times. The effects of pre-drilling, compressed air, layer of leather on a Kevlar-epoxy sheet and the innovative strategy of simultaneous use of pre-drilling and a leather layer, on the delamination factor and hole diameter error was also investigated in the present study. The results indicate a significant reduction in delamination factor and hole diameter error in simultaneous use of pre-drilling and a leather layer on the composite sheet.

Skins and hides are perishable resources that can be damaged by parasitic diseases and human error, which result in downgrading or rejection. This study was conducted to identify defect types and to determine their prevalence in pickled sheep and wet blue goat skins and wet blue hides. Each selected skin or hide was examined for defects in natural light and the defects were graded according to established quality criteria in Ethiopian standard manuals. Major defects were captured by digital photography. The major pre-slaughter defects included scratches (64.2%), cockle (ekek) (32.8%), wounds or scars (12.6%), lesions from pox or lumpy skin disease (6.1%), poor substance (5%), branding marks (2.3%) and tick bites (1.5%). The presence of grain scratches in wet blue hides (76.3%) was significantly higher than in pickled sheep (67.2%) and wet blue goat (59.1%) skins. The major slaughter defects included flay cuts or scores, holes, poor pattern and vein marks, with a higher occurrence in wet blue goat skins (28.7%; P < 0.001) than in wet blue hides (22.8%) and pickled sheep skins (11.1%). The most prevalent postslaughter defects were grain cracks (14.9%), hide beetle damage (8%), damage caused by heat or putrefaction (3.7%) and machine-induced defects (0.5%). Grain cracks (27.04%) and hide beetle damage (13.9%) in wet blue goat skins were significantly more common than in wet blue hides and pickled sheep skins. These defects cause depreciation in the value of the hides and skins. Statistically significant (P < 0.001) higher rejection rates were recorded for wet blue hides (82.9%) than for pickled sheep skins (18.3%) and wet blue goat skins (8.5%). Improved animal health service delivery, effective disease control strategies and strong collaboration between stakeholders are suggested to enhance the quality of skins and hides.

Lincolnshire, England. The crowd cheer when the ball breaks loose. From one end of the field to the other, the players chase, their snouts hovering just above the grass. It’s not a case of four legs being better, rather a novel way to attract customers to the Woodside Wildlife and Falconry Park. During the matches, volunteers are drawn from the crowd to hold goal posts at either end of the run the pigs usually race on. With five pigs playing, two teams of two and a referee, and a ball designed to leak feed as it rolls (Stevenson) the ten-minute competition is fraught with tension. While the pig’s contributions to “the beautiful game” (Fish and Pele 7) have not always been so obvious, it could be argued that specific parts of the animal have had a significant impact on a sport which, despite calls to fall into line with much of the rest of the world, people in Australia (and the US) are more likely to call soccer. The Football Precursors to the modern football were constructed around an inflated pig’s bladder (Price, Jones and Harland). Animal hide, usually from a cow, was stitched around the bladder to offer some degree of stability, but the bladder’s irregular and uneven form made for unpredictable movement in flight. This added some excitement and affected how ball games such as the often violent, calico matches in Florence, were played. In the early 1970s, the world’s oldest ball was discovered during a renovation in Stirling Castle, Scotland. The ball has a pig’s bladder inside its hand-stitched, deer-hide outer. It was found in the ceiling above the bed in, what was then Mary Queens of Scots’ bedroom. It has since been dated to the 1540s (McGinnes). Neglected and left in storage until the late 1990s, the ball found pride of place in an exhibition in the Smiths Art Gallery and Museum, Stirling, and only gained worldwide recognition (as we will see later) in 2006. Despite confirmed interest in a number of sports, there is no evidence to support Mary’s involvement with football (Springer). The deer-hide ball may have been placed to gather and trap untoward spirits attempting to enter the monarch’s sleep, or simply left by accident and forgotten (McGinnes in Springer). Mary, though, was not so fortunate. She was confined and forgotten, but only until she was put to death in 1587. The Executioner having gripped her hair to hold his prize aloft, realised too late it was a wig and Mary’s head bounced and rolled across the floor. Football Development The pig’s bladder was the central component in the construction of the football for the next three hundred years. However, the issue of the ball’s movement (the bounce and roll), the bladder’s propensity to burst when kicked, and an unfortunate wife’s end, conspired to push the pig from the ball before the close of the nineteenth-century. The game of football began to take its shape in 1848, when JC Thring and a few colleagues devised the Cambridge Rules. This compromised set of guidelines was developed from those used across the different ‘ball’ games played at England’s elite schools. The game involved far more kicking, and the pig’s bladders, prone to bursting under such conditions, soon became impractical. Charles Goodyear’s invention of vulcanisation in 1836 and the death of prestigious rugby and football maker Richard Lindon’s wife in 1870 facilitated the replacement of the animal bladder with a rubber-based alternative. Tragically, Mr Lindon’s chief inflator died as a result of blowing up too many infected pig’s bladders (Hawkesley). Before it closed earlier this year (Rhoads), the US Soccer Hall of Fame displayed a rubber football made in 1863 under the misleading claim that it was the oldest known football. By the late 1800s, professional, predominantly Scottish play-makers had transformed the game from its ‘kick-and-run’ origins into what is now called ‘the passing game’ (Sanders). Football, thanks in no small part to Scottish factory workers (Kay), quickly spread through Europe and consequently the rest of the world. National competitions emerged through the growing need for organisation, and the pig-free mass production of balls began in earnest. Mitre and Thomlinson’s of Glasgow were two of the first to make and sell their much rounder balls. With heavy leather panels sewn together and wrapped around a thick rubber inner, these balls were more likely to retain shape—a claim the pig’s bladder equivalent could not legitimately make. The rubber-bladdered balls bounced more too. Their weight and external stitching made them more painful to header, but also more than useful for kicking and particularly for passing from one player to another. The ball’s relatively quick advancement can thereafter be linked to the growth and success of the World Cup Finals tournament. Before the pig re-enters the fray, it is important to glance, however briefly, at the ball’s development through the international game. World Cup Footballs Pre-tournament favourites, Spain, won the 2010 FIFA World Cup, playing with “an undistorted, perfectly spherical ball” (Ghosh par. 7), the “roundest” ever designed (FIFA par.1). Their victory may speak to notions of predictability in the ball, the tournament and the most lucrative levels of professional endeavour, but this notion is not a new one to football. The ball’s construction has had an influence on the way the game has been played since the days of Mary Queen of Scots. The first World Cup Final, in 1930, featured two heavy, leather, twelve-panelled footballs—not dissimilar to those being produced in Glasgow decades earlier. The players and officials of Uruguay and Argentina could not agree, so they played the first half with an Argentine ball. At half-time, Argentina led by two goals to one. In the second half, Uruguay scored three unanswered goals with their own ball (FIFA). The next Final was won by Italy, the home nation in 1934. Orsi, Italy’s adopted star, poked a wildly swerving shot beyond the outstretched Czech keeper. The next day Orsi, obligated to prove his goal was not luck or miracle, attempted to repeat the feat before an audience of gathered photographers. He failed. More than twenty times. The spin on his shot may have been due to the, not uncommon occurrence, of the ball being knocked out of shape during the match (FIFA). By 1954, the Federation Internationale de Football Association (FIFA) had sought to regulate ball size and structure and, in 1958, rigorously tested balls equal to the demands of world-class competition. The 1950s also marked the innovation of the swerving free kick. The technique, developed in the warm, dry conditions of the South American game, would not become popular elsewhere until ball technology improved. The heavy hand-stitched orb, like its early counterparts, was prone to water absorption, which increased the weight and made it less responsive, particularly for those playing during European winters (Bray). The 1970 World Cup in Mexico saw football progress even further. Pele, arguably the game’s greatest player, found his feet, and his national side, Brazil, cemented their international football prominence when they won the Jules Rimet trophy for the third time. Their innovative and stylish use of the football in curling passes and bending free kicks quickly spread to other teams. The same World Cup saw Adidas, the German sports goods manufacturer, enter into a long-standing partnership with FIFA. Following the competition, they sold an estimated six hundred thousand match and replica tournament footballs (FIFA). The ball, the ‘Telstar’, with its black and white hexagonal panels, became an icon of the modern era as the game itself gained something close to global popularity for the first time in its history. Over the next forty years, the ball became incrementally technologically superior. It became synthetic, water-resistant, and consistent in terms of rebound and flight characteristics. It was constructed to be stronger and more resistant to shape distortion. Internal layers of polyutherane and Syntactic Foam made it lighter, capable of greater velocity and more responsive to touch (FIFA). Adidas spent three years researching and developing the 2006 World Cup ball, the ‘Teamgeist’. Fourteen panels made it rounder and more precise, offering a lower bounce, and making it more difficult to curl due to its accuracy in flight. At the same time, audiences began to see less of players like Roberto Carlos (Brazil and Real Madrid CF) and David Beckham (Manchester United, LA Galaxy and England), who regularly scored goals that challenged the laws of physics (Gill). While Adidas announced the 2006 release of the world’s best performing ball in Berlin, the world’s oldest was on its way to the Museum fur Volkerkunde in Hamburg for the duration of the 2006 FIFA World Cup. The Mary Queen of Scot’s ball took centre spot in an exhibit which also featured a pie stand—though not pork pies—from Hibernian Football Club (Strang). In terms of publicity and raising awareness of the Scots’ role in the game’s historical development, the installation was an unrivalled success for the Scottish Football Museum (McBrearty). It did, however, very little for the pig. Heads, not Tails In 2002, the pig or rather the head of a pig, bounced and rolled back into football’s limelight. For five years Luis Figo, Portugal’s most capped international player, led FC Barcelona to domestic and European success. In 2000, he had been lured to bitter rivals Real Madrid CF for a then-world record fee of around £37 million (Nash). On his return to the Catalan Camp Nou, wearing the shimmering white of Real Madrid CF, he was showered with beer cans, lighters, bottles and golf balls. Among the objects thrown, a suckling pig’s head chimed a psychological nod to the spear with two sharp ends in William Golding’s story. Play was suspended for sixteen minutes while police tried to quell the commotion (Lowe). In 2009, another pig’s head made its way into football for different reasons. Tightly held in the greasy fingers of an Orlando Pirates fan, it was described as a symbol of the ‘roasting’ his team would give the Kaiser Chiefs. After the game, he and his friend planned to eat their mascot and celebrate victory over their team’s most reviled competitors (Edwards). The game ended in a nil-all draw. Prior to the 2010 FIFA World Cup, it was not uncommon for a range of objects that European fans might find bizarre, to be allowed into South African league matches. They signified luck and good feeling, and in some cases even witchcraft. Cabbages, known locally for their medicinal qualities, were very common—common enough for both sets of fans to take them (Edwards). FIFA, an organisation which has more members than the United Nations (McGregor), impressed their values on the South African Government. The VuVuZela was fine to take to games; indeed, it became a cultural artefact. Very little else would be accepted. Armed with their economy-altering engine, the world’s most watched tournament has a tendency to get what it wants. And the crowd respond accordingly. Incidentally, the ‘Jabulani’—the ball developed for the 2010 tournament—is the most consistent football ever designed. In an exhaustive series of tests, engineers at Loughborough University, England, learned, among other things, the added golf ball-like grooves on its surface made the ball’s flight more symmetrical and more controlled. The Jabulani is more reliable or, if you will, more predictable than any predecessor (Ghosh). Spanish Ham Through support from their Governing body, the Real Federación Española de Fútbol, Spain have built a national side with experience, and an unparalleled number of talented individuals, around the core of the current FC Barcelona club side. Their strength as a team is founded on the bond between those playing on a weekly basis at the Catalan club. Their style has allowed them to create and maintain momentum on the international stage. Victorious in the 2008 UEFA European Football Championship and undefeated in their run through the qualifying stages into the World Cup Finals in South Africa, they were tournament favourites before a Jabulani was rolled into touch. As Tim Parks noted in his New York Review of Books article, “The Shame of the World Cup”, “the Spanish were superior to an extent one rarely sees in the final stages of a major competition” (2010 par. 15). They have a “remarkable ability to control, hold and hide the ball under intense pressure,” and play “a passing game of great subtlety [ ... to] patiently wear down an opposing team” (Parks par. 16). Spain won the tournament having scored fewer goals per game than any previous winner. Perhaps, as Parks suggests, they scored as often as they needed to. They found the net eight times in their seven matches (Fletcher). This was the first time that Spain had won the prestigious trophy, and the first time a European country has won the tournament on a different continent. In this, they have broken the stranglehold of superpowers like Germany, Italy and Brazil. The Spanish brand of passing football is the new benchmark. Beautiful to watch, it has grace, flow and high entertainment value, but seems to lack something of an organic nature: that is, it lacks the chance for things to go wrong. An element of robotic aptitude has crept in. This occurred on a lesser scale across the 2010 FIFA World Cup finals, but it is possible to argue that teams and players, regardless of nation, have become interchangeable, that the world’s best players and the way they play have become identikits, formulas to be followed and manipulated by master tacticians. There was a great deal of concern in early rounds about boring matches. The world’s media focused on an octopus that successfully chose the winner of each of Germany’s matches and the winner of the final. Perhaps, in shaping the ‘most’ perfect ball and the ‘most’ perfect football, the World Cup has become the most predictable of tournaments. In Conclusion The origins of the ball, Orsi’s unrepeatable winner and the swerving free kick, popular for the best part of fifty years, are worth remembering. These issues ask the powers of football to turn back before the game is smothered by the hunt for faultlessness. The unpredictability of the ball goes hand in hand with the game. Its flaws underline its beauty. Football has so much more transformative power than lucrative evolutionary accretion. While the pig’s head was an ugly statement in European football, it is a symbol of hope in its South African counterpart. Either way its removal is a reminder of Golding’s message and the threat of homogeneity; a nod to the absence of the irregular in the modern era. Removing the curve from the free kick echoes the removal of the pig’s bladder from the ball. The fun is in the imperfection. Where will the game go when it becomes indefectible? Where does it go from here? Can there really be any validity in claiming yet another ‘roundest ball ever’? Chip technology will be introduced. The ball’s future replacements will be tracked by satellite and digitally-fed, reassured referees will determine the outcome of difficult decisions. Victory for the passing game underlines the notion that despite technological advancement, the game has changed very little since those pioneering Scotsmen took to the field. Shouldn’t we leave things the way they were? Like the pigs at Woodside Wildlife and Falconry Park, the level of improvement seems determined by the level of incentive. The pigs, at least, are playing to feed themselves. Acknowledgments The author thanks editors, Donna Lee Brien and Adele Wessell, and the two blind peer reviewers, for their constructive feedback and reflective insights. The remaining mistakes are his own. References “Adidas unveils Golden Ball for 2006 FIFA World Cup Final” Adidas. 18 Apr. 2006. 23 Aug. 2010 . 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