Biomechanical parameters characterising the foot during normal gait

The biomechanical analysis allows to understand the normal and pathological gait, the mechanics of neuromuscular control, and last but not least, allows the visualisation of the effects of footwear on human gait or feet. Biomechanical analyses are very important for the footwear development process, as they can identify the incorrect loading of the foot or the incorrect gait pattern, thus avoiding the occurrence of deformations. This paper aims to create an average representative model of barefoot loading based on an extended group of participants by applying an optimal procedure for measuring biomechanical parameters. The variation of four basic biomechanical parameters, namely force, pressure, contact time and contact area, was measured using a pressure platform and a specialised software system. The data was collected from 32 healthy females, without particularities regarding foot health and the practice of performance sports, aged between 18 and 30 years, divided into three size groups – 36, 37 and 38. The T-Student test was applied to verify if there are significant differences between the left and right foot. Statistical indicators for each parameter were calculated, in order to characterize and establish the degree of variation of the obtained values, as follows: mean, standard deviation, minimum and maximum values, the amplitude of variation and coefficient of variation (CV). The study results confirm that the obtained mean values can be used as input data to load the foot and perform virtual simulations of footwear products.

Enzymatic activity of alkaline protease from Bacillus cereus TD5B and its application as sheep skin dehairing agent

This study aims to determine the enzymatic activity of extracellular alkaline protease from Bacillus cereus TD5B and its potential application as a sheep skin dehairing agent. The B. cereus TD5B was screened for extracellular alkaline protease production on skim milk agar media, while its alkaline protease activity and the application were measured at 1%, 1.5%, and 2%. The application of alkaline protease from B. cereus TD5B as a sheep skin dehairing agent was observed through histological examination and physical properties measurement after chrome-tanning with lime and Na2S as control. The study was conducted in a completely randomized design, and the quantitative data were analyzed using Duncan’s Multiple Range Test. The results showed that a clear zone was seen surrounding B. cereus, indicating the bacteria’s proteolytic activity. The protease activity measurement showed that 2% of alkaline protease had the highest enzymatic activity at 144.75 U/mL/min. The highest tensile strength of sheep leather was obtained after dehairing at 1% alkaline protease concentration (350.26 kg/cm2), even though the highest elongation was obtained at 2% (34.92%). In contrast, different concentrations showed similar shrinkage temperatures at 90°C. This study concludes that the optimum alkaline protease concentration from Bacillus cereus TD5B as a sheep dehairing agent was 2%.

Effect of badminton shoe sole on the lunge skill performance: in the viewpoint of coordination

Badminton lunge requires rapid coordination between the knee and ankle joints and it is accompanied by fast contact between the shoe’s sole and the floor. Phase angle analysis is a protocol with high resolution and relating to the coordination, but how the shoe’s sole would affect the lunge performance was not clear in terms of coordination. Thereby, the aim of this study was to applied phase angle analysis to insight the lunge process, then to disclose the effect of badminton shoe’s sole on the lunge skill performance. Eleven elite badminton players performed five left-forward maximum lunge trials with wearing Rounded Heel Shoe (RHS), Flattened Heel Shoe (FHS), and Standard Heel Shoes (SHS). The motion capturing system was used to measure the knee and ankle kinematics information. The Phase Angle (PA), continuous relative phase (CRP) and variability of continuous relative phase (VCRP) between the knee and ankle joints were then calculated for both forward lunge phase and recovery phase in each of the three shoes. Current findings indicated that players wearing RHS had certain advantages on better movement coordination than other shoes, as indicated by better PA and CRP. The findings of this study would be helpful to understand the coordination of badminton lunges and explain the synergy between the lower extremity ankle and knee joint to minimize the possibility of injury in badminton. Furthermore, the coordination between the knee and ankle joints was greatly affected by the structure of the shoe heel design.

Life cycle assessment of processing for chrome tanned cowhide upper leather

Pollution has become a serious problem in leather industry, however, current method to evaluate its environmental effect usually used data from literature review, those data generated while leather manufacturing were rarely collected and analyzed. Thereby, the aim of this study was to evaluate the environmental effect of manufacturing process of chrome tanned cowhide upper leather by applying the Life Cycle Assessment protocols. Following the guidance of ISO 14010, we first combined data obtained from field study and empirical review; and then these data were input into eFootprint for calculation. Results, including four environmental indicators (global warming potential [GWP], primary energy demand [PED], water utility [WU] and acidification [AP]), show that producing 1 kg of cowhide upper leather releases 7.040 kg of CO2 eq, consumes 106.793 MJ of energy and 89.144 kg of water and emits 0.058 kg of SO2 eq. Sensitivity analysis of inventory data demonstrated that chrome tanning and retanning processes accounted for more than 40% of PED, AP and GWP, whereas the beamhouse was more than 78% of WU. Therefore, we could optimise the tanning process by using alternative materials or technologies in the critical sections to achieve cleaner production and sustainable leather manufacturing.

Interaction between Gelatin and Nano-Silver Particle: Foundation for Nano-Silver in Antibacterial Leather

In order to explain the interaction between collagen and nano-silver, gelatin solution was blended with nano-silver particles (AgNPs) with particle size 26 mm, and then the mixture was interacted under different time, pH and temperature. The changes in the process were measured by UV-Vis, fluorescence spectroscopy, dynamic light scattering and FT-IR. The results showed that the main type of reaction between gelatin and AgNPs was electrostatic interaction and the interaction was diffusive encounters. The particle size and distribution of nano-silver would not be affected by gelatin, however, there was dynamic fluorescence quenching of gelatin after nano-silver particle induced. The longer time and lower pH were beneficial for the interaction process while the interaction balanced after 60 min and pH 3.0 resulted in the most drastic interaction. Moreover, nano-silver would not impair gelatin structure during the interaction process. In short, the results in this work might be a foundation and reference for applying nano-silver in antibacterial leather producing.

Down the Sewer: How Semi-Informal Tanneries Management Policies Affect Residual Water Disposal in Colombian Business Scenarios

In Colombia, the issue of waste discharges derived from the tanning process to water bodies is a scenario that has been widely documented. However, measurement exercises have failed to identify improvements in this process that integrates administrative knowledge with concepts of labor, social and environmental welfare. The present article is the culmination of research conducted within the framework of the project “Estudio comparativo de la administración y las repercusiones socio-ambientales en las empresas del sector de curtiembre. Case Bogotá (Barrio San Benito), Case Barranquilla and Case Villapinzón (Cundinamarca)” (Comparative study of the administration and the socio-environmental repercussions in tanning sector companies. Case Bogotá (Barrio San Benito), Case Barranquilla and Case Villapinzón (Cundinamarca)) concerning the administrative practices and the negative effects derived from the absence of management systems for negative externalities caused to the environment by companies in the tanning sector. The study was developed as follows: initially, a systematic documentary review of the laws, decrees and regulations that have a direct or indirect impact on the tanning sector was carried out, followed by field work using data collection instruments (questionnaires) in the San Benito neighborhood (Bogotá), in the town of Villapinzón (Cundinamarca) and in the city of Barranquilla (Atlántico), where there are formal and informal work clusters dedicated to the leather industry. The objective of this study was to identify the relationship between administrative styles and formal processes of strategic planning activities development with the adoption of dumping control systems and other aspects related to environmental management, oriented to the organizational level. Based on the above, the information was analyzed with emphasis on those companies with a common denominator in their control strategies in relation to those policies that were the result of administrative and business practices and that finally led to the desired effects in the social, environmental and economic spheres. Finally, the discussion section focuses on the recognition of these good practices and the possibility that they could be replicated by other actors on the global level.

Assessment of the Influence of Glove and Haberdashery Skin Production Technology on the Environment

Results of calculation of ecological optimality for application technologies of using chrome-aluminium, chrome-titanium, chrome-aluminium-titanium of complex compounds for production of glove and haberdashery leather are given in the article. In semi-working conditions tanning processes of glove and haberdashery leather by ecologically harmless tanner were carried out at the corresponding parameters and expenses of chemical materials. The received integrated coefficients of waste lessen of production of glove and haberdashery leather showed that offered technologies are “conventionally waste-free”.

Portraying Footwear Customer Enter-Store Behavior in China: Based on Computer Vision Technology

Existing studies on customer behavior lack quantitative and high efficiency study, their technologies rely heavily on hardware. Therefore, the information of consumers in offline stores was insufficient, which made enterprises unable to accurately track consumers. However, computer vision (CV) is an expert in identifying and tracking people’s behavior, and its function is suitable for investigating enter-store customer behavior. Therefore, the aim of our study was to develop an offline consumer behavior portraying system based on CV. Then we used this system to investigate enter-store consumption behavior. We selected 71 shoe stores in China, then installed the system in store for a three-month data collection, and evaluated the impact of customer's age, gender, enter time, and region factors on enter-store behavior in China. Through our system, we successfully study ways to improve the purchase conversion rate of enter-store consumers, which could guide enterprises to adjust better marketing and operation strategies.

Production Planning through Lean Manufacturing and Mixed Integer Linear Programming

Production planning is one of the most important administrative decisions a company can make, as it involves achieving the lead times set by the customers while taking advantage of the resources the organization has. Over time, different strategies using mathematical models have been implemented in production planning, aimed at finding the best solution for optimizing the available resources. In recent years companies throughout the world have successfullly implemented Lean Manufacturing, aimed at improving their production processes and eliminating everything that does not add value to the product. This article exemplifies a new strategy for production planning, using basic concepts from Lean Manufacturing and mixed integer linear programming models by stages. We took a women’s footwear factory in the city of León, Guanajuato, México, as a case study. The results show that it is possible to get planning that optimizes the organization’s resources and shortens the products’ lead times by shrinking inventories, from a Lean Manufacturing perspective.

Laser Modification of Leather and Fur Surface to Improve Its Quality when Conducting Finishing Operations

The article discusses the problems of activation of the surface of the leather tissue by laser exposure, changes in the morphology of the surface of the leather tissue during laser processing, and subsequent covering dyeing of the leather. It is shown that laser treatment changes the structure of the surface of the leather tissue, the bundles of collagen fibers are split, the structure becomes loose, which increases the diffusion of the coating dye reagents, and their reactivity increases without chemical modification. In the process of grinding leather fabric, it is finely cleaned which improves adhesion of the coating paint to the surface of the leather fabric, which improves the quality of leather fabric products. It was shown that laser exposure under the conditions found (pulses with an interval of 3 μs, a duration of 10 ns) does not cause destruction and configuration changes in collagen.