Leather and Footwear Journal

Volume 24, no 1

Contents
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CHANGES IN LOWER LIMB COORDINATION ACROSS RUNNING AT DIFFERENT SPEEDS AND INCLINATIONS: CONTINUOUS RELATIVE PHASE ANALYSIS
- Pages 3-14
  Yichun SUN¹, Zhao YEBAO², Quting HUANG¹, Jin ZHOU^{1, *}, Jie ZENG³, Wing-Kai LAM^{4, *}
  - ¹National Engineering Laboratory for Clean Technology of Leather Manufacture, Sichuan University, Chengdu 610000, China, sunyichun@stu.scu.edu.cn
  - ²Zhejiang Huafeng new material Co., LTD. Wenzhou Zhejiang Province, P.R. China. 325200
  - ³College of Electronics and Information, Sichuan University, Intelligent Control Institute, Chengdu 610065, China
  - ⁴Li Ning Sports Science Research Center, Li Ning (China) Sports Goods Company, Beijing 101111, China
  ABSTRACT. The aim of this study was to evaluate the changes in segmental coordination when running at different inclinations and speeds. 18 recreational runners performed running trials at three inclinations (0°, 3° and 6°) and three speeds (preferred speed, fast and slow) were measured with Vicon motion capturing system. The phase angle, continuous relative phase (CRP) and variability of CRP (VCRP) were calculated. Statistical models were performed to compare means for each running condition at each gait point: one-way ANOVA with Bonferroni post-hoc analysis for those data points with homogeneity of variances and Welch ANOVA with Games-Howell post-hoc analysis for those with heterogeneity of variance. Effect size (ω²) was computed to indicate whether the significant effects were trivial. Our results demonstrated that compared with the running speeds, participants who ran on different inclined surfaces showed higher Ankle-Knee CRP but lower Knee-Hip CRP and its variability, which is susceptible to running related injuries. These data suggest that runners should have a higher concern on joint loading and sports recovery when running at inclined surfaces.
  
  KEY WORDS: treadmill running, continuous relative phase, coordination pattern, running with inclinations, running injuries
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DEVELOPING INNOVATIVE BALLET POINTE SHOES: A LEAN STARTUP AND DESIGN THINKING APPROACH
- Pages 15-32
  Silvia GARCÍA DE VAL*
  - Universitat Politècnica de València, Camino de Vera, s/n, Edificio 7B, 46022 Valencia, silgard1@doctor.upv.es
  ABSTRACT. This study aims to explore the development of innovative ballet pointe shoes through the implementation of Lean Startup and Design Thinking methodologies. The research employs a multi-phase approach, including problem identification, concept development, market testing, and model refinement. Through iterative improvements and user feedback, the study seeks to create a model of pointe shoes that offers enhanced comfort, adaptability, and durability for ballet dancers. The research emphasizes the use of polymers and 3D printing in the manufacturing process, presenting opportunities for advancements in pointe shoe design. By incorporating new technologies and materials, the study contributes to the field of classical dance footwear. The proposed innovative solution holds potential to elevate the dancer's experience and performance in pointe shoes.
  
  KEY WORDS: pointe shoes, innovation, Lean Startup, Design Thinking, 3D printing
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COMPETENCY OF Acacia mearnsii TANNIN EXTRACT FOR VEGETABLE TANNING USING ULTRASOUND TECHNIQUE
- Pages 33-42
  Md. Abu SAYID MIA^{1, 2}, Shamima YEASMIN¹, Mohammad NURNABI¹, Md. Zahangir ALAM^{1, *}
  - ¹Department of Applied Chemistry and Chemical Engineering, University of Dhaka, Dhaka 1000, Bangladesh
  - ²Centre for Advanced Research in Sciences (CARS), University of Dhaka, Dhaka 1000, Bangladesh
  ABSTRACT. This article describes the potential of Acacia mearnsii tannin extract for environmentally friendly vegetable tanning of leather using ultrasound. Vegetable tanning is a versatile but time-consuming process in the leather industry, particularly for heavy leather which needs more than one week for tanning using natural tanning materials. So, it is significant to develop new eco-friendly techniques employing ultrasound to speed up the vegetable tanning process without affecting the quality of the finished leather. In this study, the effect of ultrasound in vegetable tanning has been evaluated to enhance the tanning process. The effects of various parameters for example tannin dose, tanning time, temperature, and variable frequencies were studied. Tannin uptakes and other thermal properties were also investigated.
  
  KEY WORDS: vegetable tanning, Acacia mearnsii, ultrasound, thermal stability, optimization
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TESTING AND ASSESSING FUNCTIONALITY OF KERATIN HYDROLYSATE WITH AGRICULTURAL APPLICATION ON WHEAT SEEDS
- Pages 43-50
  Mariana Daniela BERECHET*, Carmen GAIDĂU, Demetra SIMION
  - INCDTP – Division: Leather and Footwear Research Institute, 93 Ion Minulescu St., Sector 3, Bucharest, Romania, e-mail: marianadanielaberechet@yahoo.co.uk
  ABSTRACT. This work aimed to obtain, characterize and evaluate keratin hydrolyzate with specific properties for applications in agriculture. The KerKAgr product, made by hydrolysing sheep wool with potassium hydroxide, was applied to wheat seeds. Physico-chemical analyses show that the keratin hydrolyzate obtained is rich in minerals, nitrogen and protein substances necessary in the plant growth process. Keratin hydrolyzate, KerKAgr, was used in treatments on Tamino and Mirastar wheat seeds, and the observations made showed an improvement in the germination rate and a stimulation of plant growth. KerKAgr 3% and 5% was used to treat wheat seeds and then germination and plant growth were monitored. The effect of keratin hydrolyzate was evaluated for 10 days on the two types of wheat (Tamino and Mirastar) treated with keratin hydrolyzate. The results of the treatments indicated an increased stimulation of seed germination by 10-20% compared to the control and a growth of wheat plants by 7.1-21.7% compared to the control. The biostimulating effect of keratin hydrolyzate has been highlighted. The good results obtained in the applications of keratin hydrolyzate in agriculture show that keratin hydrolyzate can be the basis for obtaining new biomaterials with various applications.
  
  KEY WORDS: keratin hydrolyzate, biostimulator, seed germination
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RECENT DEVELOPMENTS IN ENVIRONMENT-FRIENDLY METHODS FOR VALUING LEATHER WASTE AS A MEANS OF PROMOTING THE CIRCULAR ECONOMY: A COMPREHENSIVE REVIEW
- Pages 51-72
  Md. Abdus SHABUR*, Md. Amjad HOSSAIN
  - Institute of Leather Engineering and Technology, University of Dhaka, Dhaka-1209, Bangladesh, abdusshabur@du.ac.bd, amjad@du.ac.bd
  ABSTRACT. The leather processing industry produces a significant quantity of waste materials, which can be treated in a manner that is consistent with the concepts underlying the circular economy. This article provides an overview of ways to recycle substances or energy from tannery waste, such as thermal, biological, chemical and other procedures. These approaches have the potential to facilitate the recovery and recycling of a diverse range of recyclable chemical substances like chromium, fats, gelatin vitamins, hydrolysate and minerals, biomass, and microbial waste products for use in other manufacturing operations. All the methods related to leather waste valorization have been discussed in this study to illustrate the recent development in techniques and processes of leather waste. The incorporation of the concept of circular economy has also been depicted. The premise of the circular economy model is that any waste product from the leather industry may be recycled and utilized again in the leather-producing process or in other related sectors. This study demonstrates that the circular economy approach to leather production offers chances for collaboration and innovation across several industries. Collaboration among organizations may lead to the discovery of innovative methods to minimize waste, enhance productivity, and extract value from resources that would otherwise be disposed of. The overview also addresses the state of waste legislation today and how it affects the environment. Technologies for sustainable and intelligent valuation allow for high recycling levels without negatively impacting the natural environment.
  
  KEY WORDS: tannery, waste, valorization, sustainability, chromium
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CHARACTERIZATION OF ENZYME-TREATED ECO-FRIENDLY IRON TANNED LEATHER
- Pages 73-82
  Md. Abu SAYID MIA^{1, 2, *}, Nadia Sultana MILY², Md. Arafat Al MAMUN¹, Md. Farhad ALI², Uttam Kumar ROY²
  - ¹Centre for Advanced Research in Sciences (CARS), University of Dhaka, Bangladesh
  - ²Institute of Leather Engineering and Technology, University of Dhaka, Bangladesh
  ABSTRACT. Tanning is the process of converting putrescible raw hides and skins into non-putrescible leather. The most common chrome tanning process is not eco-friendly at all. But the increasing demand for leather leads us to find an eco-friendly tanning process. Therefore, the elimination of pollution due to the use of chrome and dyeing material is a matter of concern here. The primary objectives of this study are the reduction of pollution from using chrome and dyeing materials in the tanning process and their impacts on human life as well as the environment. In this study, different types of iron salts, combinations of different iron salts, and iron with chromium salts are used for tanning and no dyeing material is used to give color to the leather. On the other hand, various types of enzymes were applied for the completion of the beamhouse operation. Finally, the physical and thermal properties of various tanned leather were summarized to propagate an eco-friendly new tanning method.
  
  KEY WORDS: enzyme, iron tanning, chrome tanning, physical properties, eco-friendly
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