Development of upper cycling clothes using 3D-to-2D flattening technology and evaluation of dynamic wear comfort from the aspect of clothing pressure

2016 ◽  
Vol 28 (6) ◽  
pp. 736-749 ◽  
Author(s):  
Kaixuan Liu ◽  
Jianping Wang ◽  
Chun Zhu ◽  
Yan Hong
Keyword(s):  
Dynamic Condition ◽  
Dynamic Pressure ◽  
Static Condition ◽  
Measuring Method ◽  
3D Animation ◽  
Content Type ◽  
Wear Comfort ◽  
Clothing Pressure ◽  
Static Conditions ◽  
Dynamic Wear

Purpose Currently, the researches on garment development and wear comfort evaluation mainly focus on the static condition type and seldom involved dynamic condition. Therefore, the purpose of this paper is to develop cycling clothes’ patterns and evaluate their dynamic wear comfort. Design/methodology/approach First, the 3D-to-2D flattening technology was applied to develop garment patterns of a cycler’s jersey T-shirt. Then, 3D animation technology was used to simulate the scene of cycling. Next, a novel pressure-measuring method was proposed to measure static and dynamic clothing pressures in a virtual environment. Finally, the collected data were used for evaluating wear comfort. Findings Compared to static conditions, the dynamic wear comfort noticeably improved at the front neck, side neck, upper front chest, around back neck point and front shoulder, and the front neck. Compared to static conditions, the dynamic wear comfort visibly deteriorates at the back neck, below chest, outseam, back except around back neck point and around scapula, and the around scapula area. The dynamic pressure at back neck, below front chest and shoulder fluctuate wildly throughout the whole cycling. On the contrary, the dynamic pressure at the front neck, side neck, front upper chest and at the back cause it to tend to stability during cycling. Originality/value The 3D virtual-reality technology was applied to simulate cycling. And a novel method was proposed to measure numerical clothing pressures for evaluating the dynamic wear comfort. The proposed method can not only quantitatively evaluate the wear comfort of cycling clothes and optimize cycling clothes’ patterns, but also can be applied to other tight garment types.

scholarly journals Behavior of Elastic Therapeutic Tapes under Dynamic and Static Conditions

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Hermela Ejegu ◽  
Bipin Kumar ◽  
Priyanka Gupta
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Internal Stress ◽  
Dynamic Condition ◽  
Physical And Mechanical Properties ◽  
Static Condition ◽  
Strain Rates ◽  
Lower Strain Rate ◽  
Lower Strain ◽  
Static Conditions

The aim of this paper is to determine the relaxation behavior of the therapeutic tape under different thermomechanical conditions over different time spans and to analyze the physical and mechanical properties of selected kinesiology tapes. The relaxation test was conducted under a static condition with two extended levels (25% and 50%) for one hour and a dynamic condition for 300 cycles with different loading-unloading values, strain rates, and temperatures. For both static and dynamic conditions, at a lower strain rate and higher load and temperature, the therapeutic tapes showed higher loss of internal stress and faster losses of efficiency. Under all selected conditions, the tape’s stress has decreased rapidly.

scholarly journals Just noticeable differences for elbow joint torque feedback

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hubert Kim ◽  
Alan T. Asbeck
Keyword(s):  
Elbow Joint ◽  
Spatial Information ◽  
Dynamic Condition ◽  
Pressure Sensors ◽  
Static Condition ◽  
Joint Torque ◽  
Just Noticeable Difference ◽  
Joint Torques ◽  
Static Conditions ◽  
Joint Torque Feedback

AbstractJoint torque feedback is a new and promising means of kinesthetic feedback imposed by a wearable device. The torque feedback provides the wearer temporal and spatial information during a motion task. Nevertheless, little research has been conducted on quantifying the psychophysical parameters of how well humans can perceive external torques under various joint conditions. This study aims to investigate the just noticeable difference (JND) perceptual ability of the elbow joint to joint torques. The paper focuses on the ability of two primary joint proprioceptors, the Golgi-tendon organ (GTO) and muscle spindle (MS), to detect elbow torques, since touch and pressure sensors were masked. We studied 14 subjects while the arm was isometrically contracted (static condition) and was moving at a constant speed (dynamic condition). In total there were 10 joint conditions investigated, which varied the direction of the arm’s movement and the preload direction as well as torque direction. The JND torques under static conditions ranged from 0.097 Nm with no preload to 0.197 Nm with a preload of 1.28 Nm. The maximum dynamic JND torques were 0.799 Nm and 0.428 Nm, when the arm was flexing and extending at 213 degrees per second, respectively.

Investigation on thermal comfort of the uniform for workers in tropical monsoon climates

2020 ◽  
Vol 32 (6) ◽  
pp. 849-868
Author(s):  
Jingxian Xu ◽  
Huijuan Liu ◽  
Yunyi Wang ◽  
Jun Li
Keyword(s):  
Heat Transfer ◽  
Thermal Comfort ◽  
Dynamic Condition ◽  
Thermal Manikin ◽  
Content Type ◽  
Wind Speeds ◽  
Subjective Perceptions ◽  
Tropical Monsoon ◽  
Four Levels ◽  
Thermal Insulations

PurposeThis study aims to investigate the heat transfer mechanism of the uniforms used by people working in hot, humid and windy environments. Furthermore, the effectiveness of an opening structure added to the armpit of the uniforms in improving thermal comfort was comparatively examined.Design/methodology/approachA set of uniforms was tested with the opening at the armpit alternatively zipped or unzipped. Thermal manikin and human tests were performed in a climatic chamber simulating the specific environmental conditions, including wind speeds at four levels (0.15, 0.5, 2, 4 m/s) and relative humidities at two levels (50 and 85%). Static and dynamic thermal insulations of clothing (IT) were examined by the thermal manikin tests. The human bodies' thermal responses, including heart rates (HR), eardrum temperatures (Te), skin temperatures (Tsk) and subjective perceptions, were given by the human tests.FindingsSpecial mechanisms of heat transfer in the specific uniforms used in tropical monsoon climates were revealed. Reductions on IT were caused by the movement of the human body and the environmental wind, and the empirical equations would underestimate this reduction. The opening at the armpit was able to prompt more heat transfer under dynamic condition, with reducing the IT by 11.8%, lowering the mean Tsk by 0.92°C, and significantly improving the subjective perceptions (p < 0.05). The heat exhaustion was alleviated with lowering the Te by 0.32°C.Originality/valueThis study managed to improve the thermal performance of uniforms for workers under unforgiving conditions. The evaluation and design methods introduced by this study provided practical guidance for similar products with strict dress codes and cost control requirements based on the findings from thorough product tests and analysis.

scholarly journals Postural Control Disturbances Induced by Virtual Reality in Stroke Patients

2021 ◽  
Vol 11 (4) ◽  
pp. 1510
Author(s):  
Charles Morizio ◽  
Maxime Billot ◽  
Jean-Christophe Daviet ◽  
Stéphane Baudry ◽  
Christophe Barbanchon ◽  
...  
Keyword(s):  
Virtual Reality ◽  
Postural Control ◽  
Virtual Environments ◽  
Center Of Pressure ◽  
Dynamic Condition ◽  
Static Condition ◽  
Stroke Patients ◽  
Post Stroke ◽  
Subacute Stroke

People who survive a stroke are often left with long-term neurologic deficits that induce, among other impairments, balance disorders. While virtual reality (VR) is growing in popularity for postural control rehabilitation in post-stroke patients, studies on the effect of challenging virtual environments, simulating common daily situations on postural control in post-stroke patients, are scarce. This study is a first step to document the postural response of stroke patients to different challenging virtual environments. Five subacute stroke patients and fifteen age-matched healthy adults were included. All participants underwent posturographic tests in control conditions (open and closed eyes) and virtual environment without (one static condition) and with avatars (four dynamic conditions) using a head-mounted device for VR. In dynamic environments, we modulated the density of the virtual crowd (dense and light crowd) and the avoidance space with the avatars (near or far). Center of pressure velocity was collected by trial throughout randomized 30-s periods. Results showed that more challenging conditions (dynamic condition) induced greater postural disturbances in stroke patients than in healthy counterparts. Our study suggests that virtual reality environments should be adjusted in light of obtaining more or less challenging conditions.

Establishment of a resazurin-based aortic valve tissue viability assay for dynamic culture in a microphysiological system

2021 ◽  
pp. 1-12
Author(s):  
C. Dittfeld ◽  
M. Winkelkotte ◽  
S. Behrens ◽  
F. Schmieder ◽  
A. Jannasch ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Dynamic Condition ◽  
Thermoplastic Polyurethane ◽  
Membrane Integrity ◽  
Tissue Viability ◽  
Preliminary Results ◽  
Dynamic Culture ◽  
Resazurin Assay ◽  
Static Conditions

BACKGROUND/AIM: Tissue pathogenesis of aortic valve (AV) stenosis is research focus in cardiac surgery. Model limitations of conventional 2D culture of human or porcine valvular interstitial/endothelial cells (VIC/VECs) isolated from aortic valve tissues but also limited ability of (small) animal models to reflect human (patho)physiological situation in AV position raise the need to establish an in vitro setup using AV tissues. Resulting aim is to approximate (patho)physiological conditions in a dynamic pulsatile Microphysiological System (MPS) to culture human and porcine AV tissue with preservation of tissue viability but also defined ECM composition. MATERIALS/METHODS: A tissue incubation chamber (TIC) was designed to implement human or porcine tissues (3×5 mm) in a dynamic pulsatile culture in conventional cell culture ambience in a MPS. Cell viability assays based on lactate dehydrogenase (LDH)-release or resazurin-conversion were tested for applicability in the system and applied for a culture period of 14 days with interval evaluation of tissue viability on every other day. Resazurin-assay setup was compared in static vs. dynamic culture using varying substance saturation settings (50–300μM), incubation times and tissue masses and was consequently adapted. RESULTS: Sterile dynamic culture of human and porcine AV tissue segments was established at a pulsatile flow rate range of 0.9–13.4μl/s. Implementation of tissues was realized by stitching the material in a thermoplastic polyurethane (TPU) –ring and insertion in the TIC-MPS-system. Culture volume of 2 ml caused LDH dilution not detectable in standard membrane integrity assay setup. Therefore, detection of resazurin-conversion of viable tissue was investigated. Optimal incubation time for viability conversion was determined at two hours at a saturated concentration of 300μM resazurin. Measurement in static conditions was shown to offer comparable results as dynamic condition but allowing optimal handling and TIC sterilization protocols for long term culture. Preliminary results revealed favourable porcine AV tissue viability over a 14 day period confirmed via resazurin-assay comparing statically cultured tissue counterparts. CONCLUSIONS: Human and porcine AV tissue can be dynamically cultured in a TIC-MPS with monitoring of tissue viability using an adapted resazurin-assay setup. Preliminary results reveal advantageous viability of porcine AV tissues after dynamic TIC-MPS culture compared to static control.

Electrochemical Kinetic of a Low Carbon Steel in Seawater at Different Flow Speed

2015 ◽  
Vol 1766 ◽  
pp. 73-80
Author(s):  
A. Carmona ◽  
R. Orozco-Cruz ◽  
E. Mejía-Sánchez ◽  
A. Contreras ◽  
R. Galván-Martínez
Keyword(s):  
Turbulent Flow ◽  
Rotation Speed ◽  
Electrochemical Impedance ◽  
Static Condition ◽  
Flow Speed ◽  
Localized Corrosion ◽  
Low Carbon ◽  
Flow Conditions ◽  
Static Conditions ◽  
Turbulent Flow Conditions

ABSTRACTAn electrochemical impedance spectroscopy (EIS) corrosion study of API X70 steel was carried out in synthetic seawater with different rotation speeds using a rotating cylinder electrode (RCE) to control the hydrodynamic conditions at room temperature, atmospheric pressure and 24 h of exposure time. A superficial analysis through a scanning electron microscope (SEM) was used to analyze the corrosion type. The rotation speed used was 0 rpm (static condition), 1000, 3000 and 5000 rpm (turbulent flow). The results show that the turbulent flow conditions affect directly the corrosion rate (CR) of the steel, because all values of the CR under turbulent flow conditions are higher than the CR values at static conditions. In addition, it is important to point out that at turbulent flow conditions, the CR increased as the rotation speed also increased. The morphology of the corrosion in all experiments was localized corrosion.

Use of Opuntia ficus extract as a corrosion inhibitor for carbon steel in acidic media

2014 ◽  
Vol 61 (4) ◽  
pp. 224-231 ◽  
Author(s):  
Ruben Suarez-Hernandez ◽  
Jose G. Gonzalez-Rodriguez ◽  
Gloria F. Dominguez-Patiño ◽  
Alberto Martinez-Villafañe
Keyword(s):  
Carbon Steel ◽  
Chemical Structure ◽  
Electrochemical Impedance ◽  
Green Inhibitor ◽  
Opuntia Ficus Indica ◽  
Content Type ◽  
Acid Cleaning ◽  
Static Conditions ◽  
The Cost ◽  
Practical Implications

Purpose – The purpose of this investigation is to study the corrosion inhibition of carbon steel (CS) using a “green” inhibitor, Opuntia ficus-indica, in an aerated, 0.5 M H2SO4 solution at different concentrations and temperatures. Design/methodology/approach – Weight loss determinations, surface studies, electrochemical impedance spectroscopy and potentiodynamic polarization were applied during the investigation. Findings – It was observed that Opuntia ficus-indica extract can decrease the corrosion rate of CS, and its efficiency increases with increasing concentration up to 1,000 ppm and with time, but decreases with increasing the temperature from 25 to 600C. The inhibitory activity is due to the presence of phenolic compounds in its chemical structure. Research limitations/implications – The work was done under static conditions, whereas in acid cleaning conditions, there is a dynamic system. However, the findings may apply to both the systems. Practical implications – CS is used in acidic environments in the acid cleaning industry. Social implications – Results of this work show that it is possible to reduce the cost of repair of equipment and the environmental impact of corrosion. Originality/value – There are very few investigations on the study of Opuntia ficus-indica leaf extract as a green inhibitor in an acidic environment.

NUMERICAL SIMULATION OF THE LIGHT AIRCRAFT PROPELLER NOISE UNDER STATIC CONDITION

Akustika ◽  
2021 ◽  
pp. 100-106
Author(s):  
sergey Timushev ◽  
Alexey Yakovlev ◽  
Petr Moshkov
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Numerical Modeling ◽  
Vortex Method ◽  
Static Condition ◽  
Semiempirical Model ◽  
Calculation Methods ◽  
Propeller Noise ◽  
Calculation Results ◽  
Static Conditions

The problem of simulation the noise generated during the operation of the propeller is considered. Calculation methods are described and numerical simulation of the noise of a light aircraft propeller by the acoustic-vortex method is performed. The results of numerical modeling of the tonal components of the propeller noise when operating under static conditions are compared with experimental data and calculation results based on a semiempirical model.

scholarly journals Mechanical Stimuli Affect Escherichia coli Heat-Stable Enterotoxin-Cyclic GMP Signaling in a Human Enteroid Intestine-Chip Model

2019 ◽  
Vol 88 (3) ◽  
Author(s):  
Laxmi Sunuwar ◽  
Jianyi Yin ◽  
Magdalena Kasendra ◽  
Katia Karalis ◽  
James Kaper ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cell ◽  
Cyclic Gmp ◽  
Cyclic Stretch ◽  
Intestinal Bacterium ◽  
Mechanical Forces ◽  
Mechanical Stimuli ◽  
Content Type ◽  
Heat Stable ◽  
Static Conditions

ABSTRACT Modeling host-pathogen interactions with human intestinal epithelia using enteroid monolayers on permeable supports (such as Transwells) represents an alternative to animal studies or use of colon cancer-derived cell lines. However, the static monolayer model does not expose epithelial cells to mechanical forces normally present in the intestine, including luminal flow and serosal blood flow (shear force) or peristaltic forces. To determine the contribution of mechanical forces in the functional response of human small intestine to a virulence factor of a pathogenic intestinal bacterium, human jejunal enteroids were cultured as monolayers in microengineered fluidic-based Organ-Chips (Intestine-Chips) exposed to enterotoxigenic Escherichia coli heat-stable enterotoxin A (ST) and evaluated under conditions of static fluid, apical and basolateral flow, and flow plus repetitive stretch. Application of flow increased epithelial cell height and apical and basolateral secretion of cyclic GMP (cGMP) under baseline, unstimulated conditions. Addition of ST under flow conditions increased apical and basolateral secretion of cGMP relative to the level under static conditions but did not enhance intracellular cGMP accumulation. Cyclic stretch did not have any significant effect beyond that contributed by flow. This study demonstrates that fluid flow application initiates changes in intestinal epithelial cell characteristics relative to those of static culture conditions under both baseline conditions and with exposure to ST enterotoxin and suggests that further investigations of the application of these mechanical forces will provide insights into physiology and pathophysiology that more closely resemble intact intestine than study under static conditions.

scholarly journals A Measurement-Data-Driven Control Approach towards Variance Reduction of Micromachined Resonant Accelerometer under Multi Unknown Disturbances

Micromachines ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 294 ◽  
Author(s):  
Qiang Shen ◽  
Dengfeng Yang ◽  
Jie Zhou ◽  
Yixuan Wu ◽  
Yinan Zhang ◽  
...  
Keyword(s):  
Variance Reduction ◽  
Dynamic Condition ◽  
Measurement Data ◽  
Static Condition ◽  
Measurement Model ◽  
Data Driven ◽  
Least Mean Square ◽  
Accelerometer Sensor ◽  
Control Approach ◽  
Resonant Accelerometer

This paper first presents an adaptive expectation-maximization (AEM) control algorithm based on a measurement-data-driven model to reduce the variance of microelectromechanical system (MEMS) accelerometer sensor under multi disturbances. Significantly different characteristics of the disturbances, consisting of drastic-magnitude, short-duration vibration in the external environment, and slowly-varying, long-duration fluctuation inside the sensor are first constructed together with the measurement model of the accelerometer. Next, through establishing a data-driven model based on a historical small measurement sample, the window length of filter of the presented algorithm is adaptively chosen to estimate the sensor state and identify these disturbances simultaneously. Simulation results of the proposed AEM algorithm based on experimental test are compared with the Kalman filter (KF), least mean square (LMS), and regular EM (REM) methods. Variances of the estimated equivalent input under static condition are 0.212 mV, 0.149 mV, 0.015 mV, and 0.004 mV by the KF, LMS, REM, and AEM, respectively. Under dynamic conditions, the corresponding variances are 35.5 mV, 2.07 mV, 2.0 mV, and 1.45 mV, respectively. The variances under static condition based on the proposed method are reduced to 1.9%, 2.8%, and 27.3%, compared with the KF, LMS, and REM methods, respectively. The corresponding variances under dynamic condition are reduced to 4.1%, 70.1%, and 72.5%, respectively. The effectiveness of the proposed method is verified to reduce the variance of the MEMS resonant accelerometer sensor.

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