EFFECT OF ARCH PAD ON ANKLE JOINT PRONATION DURING GAIT WITH DIFFERENT TREADMILL SPEEDS

The purpose of this study was to evaluate the effect of an arch pad on changes of threedimensional (3D) ankle joint kinematics while walking and running at three different treadmill speeds (5km/h, 7km/h, and 10km/h). Six healthy male subjects were tested. Walking (5km/h) and running (7km/h,10km/h) motions with two shoe conditions (with and without medical arch pad) on a treadmill were analyzed by a motion capture system (Vicon-MX, 10 cameras, 250Hz). The effects of medial arch pad on foot eversion motion were found to be effective with all treadmill speeds. Additionally, the interaction between shoe conditions and gait speeds on eversion angle was significant(

INVERSE DYNAMIC CALCULATION OF 3D ANKLE JOINT KINETICS DURING GAIT: THE INFLUENCE OF CENTER OF PRESSURE DATA

The purpose of this study was to jnvestigate the effect of the errors in the center of pressure (CoP) locations on three-dimensional (3D) ankle joint torque during the stance phase of gait. Kinematic and kinetic data from one healthy male subject (age: 22 yrs, height: 180 cm, body mass: 80 kg) were collected. Changes in ankle joint torque, calculated during inverse dynamics, during the stance phase of walking were obtained using simulated CoP data with up to ± 30 mm shifts in antero-posterior and medio-Iateral directions. Shift of the CoP in the antero-posterior direction caused a change of magnitude of the plantarflexor torque, while the torque pattern was not altered. On the other hand & change of the ankle inversion/eversion torques were greatly influenced by the CoP shifts in the medio-latera'l directions. A shift of ± 10 mm of CoP in the medio-Iateral direction caused a switch in the inversion/eversion torque of ankle joint. These results suggest the importance of accurate CoP determinations in inverse dynamics procedures

Experimental Study on the Fire Resistance Performance of Prestressed Composite Beam with Corrugated Web under Standard Fire with Loading Condition

In this study, fire resistance tests were performed on a conventional slim floor beam and a prestressed composite beam with corrugated webs, which is suitable for a long-span structure with a reduction in story height by utilizing the prestress and accordion effect. In the fire test program, the ISO 834 standard fire curve was adopted. Key test variables were the effect of prestress, shape of corrugated webs, and thickness of sprayed fireproofing material. All of the test specimens demonstrated enhanced fire resistance performance exceeding the expected performance level. The prestressed composite beams with corrugated webs especially showed excellent fire performance, considering these specimens had thin fireproofing thickness compared to the conventional slim floor specimen

Experimental Study on Fire Resistance Performance of a Hollow Slab Using a Lightweight Hollow Sphere

This study evaluates the fire resistance performance (1–2h) of a reinforced concrete (RC) structure-void slab using a lightweight hollow sphere, which can reduce the unnecessary dynamic of removing the central concrete. For this experiment, we set up the depth of the concrete cover, live load, and span length as the factors. The result comes out with 50 mm cover depth of the RC structure hollow slab secured. It was shown that 120 minutes of fire resistance performance can be secured regardless of the length of the structure and loading. Among these factors, the resisting capability changes more sensitively with the live load rather than the thickness of cover. The shorter span in length could assure better fire resistance performance

The Study on Fire Safety by a Real-Scale Combustion Experiment of Composite Material

In this study, a real-scale combustion experiment was carried out for a Styrofoam and glass wool sandwich panel to figure out the fire safety for the composite material used for a building. In the experiment, a heat release rate of a sandwich panel was measured by the ISO 9705 fire test method. Research has also tested and compared temperature change in the Large Scale Calorimeter (LSC) experiment equipment to evaluate the structural safety of the structure body. As a result of the experiment, the structural body with the Styrofoam sandwich panel collapsed which was caused by propagation, and in case of the glass wool sandwich panel, the combustion did no propagate inside. Since the composite material experiences various types of fire hazards depending on the combustion characteristics of the core material, the exact combustion characteristic should be expected by the full-scale combustion experiment

EFFECTS OF VARIOUS BIOMECHANICAL ERRORS ON COMPUTED JOINT KINETICS VALUES

Inverse dynamics analysis has been widely used to evaluate the joint kinetics during various human movements. Several investigators have reported that the joint kinetic computations could be considerably affected by diverse biomechanical errors. Kim et al (2007) clarified the influence of measurement errors of Center of Pressure (CoP) location of force platform on calculated three-dimensional (3D) lower limb joint moment during walking. However, it is not yet clear how biomechanical errors, such as errors in CoP, Body Segment Parameters (BSP) and Joint Center Location (JCL) data, affect the calculated joint kinetics values. The purpose of this study was to clarify the influences of the alterations of anthropometric, kinematic, and kinetic variables on the magnitude and time-series curve patterns of the 3D ankle joint moment during human running

Syk/Src Pathway-Targeted Inhibition of Skin Inflammatory Responses by Carnosic Acid

Carnosic acid (CA) is a diterpene compound exhibiting antioxidative, anticancer, anti-angiogenic, anti-inflammatory, anti-metabolic disorder, and hepatoprotective and neuroprotective activities. In this study, the effect of CA on various skin inflammatory responses and its inhibitory mechanism were examined. CA strongly suppressed the production of IL-6, IL-8, and MCP-1 from keratinocyte HaCaT cells stimulated with sodium lauryl sulfate (SLS) and retinoic acid (RA). In addition, CA blocked the release of nitric oxide (NO), tumor necrosis factor (TNF)-α, and prostaglandin E2 (PGE2) from RAW264.7 cells activated by the toll-like receptor (TLR)-2 ligands, Gram-positive bacterium-derived peptidoglycan (PGN) and pam3CSK, and the TLR4 ligand, Gram-negative bacterium-derived lipopolysaccharide (LPS). CA arrested the growth of dermatitis-inducing Gram-positive and Gram-negative microorganisms such Propionibacterium acnes, Pseudomonas aeruginosa, and Staphylococcus aureus. CA also blocked the nuclear translocation of nuclear factor (NF)-κB and its upstream signaling including Syk/Src, phosphoinositide 3-kinase (PI3K), Akt, inhibitor of κBα (IκBα) kinase (IKK), and IκBα for NF-κB activation. Kinase assays revealed that Syk could be direct enzymatic target of CA in its anti-inflammatory action. Therefore, our data strongly suggest the potential of CA as an anti-inflammatory drug against skin inflammatory responses with Src/NF-κB inhibitory properties

Study on prevention of spread of vertical fire along finishing materials for external wall of high-rise buildings

Although there are laws in the Korea Building Act relating to exterior finishing materials, fireproof structures and fire-stop of curtain wall structures, the standards relating to and test methods on securing detailed fire safety functions for exterior materials of all buildings including high-rise buildings have not been prepared. This is due to the fact that test methods and standards to quantitatively evaluate the vertical fire spread of the exterior material of buildings do not exist. In addition, while semi non-combustible materials or non-combustible materials are required to be used to prevent fire spread in buildings which exceed 30-stories, it is necessary to review the standards and regulations in cases where fire blocking systems, capable of preventing the vertical fire spread within the curtain wall, are installed to consider permitting the utilization of fire retardant material following an assessment of the construction characteristics of high-rise buildings. The functional evaluation standards and test methods on the vertical fire spread introduced in this study will be a more effective method for performing evaluations to prevent fire spread compared to the currently utilized method of performing small scale tests

Fire Damage Assessment of Reinforced Concrete Structures Using Fuzzy Theory

Once a reinforced concrete (RC) structure is damaged by fire, the fire damage assessment should proceed to take appropriate post-fire actions, including the decision-making of whether it can be repaired for reuse or not. Since the assessment results of current fire damage diagnosis methods, however, highly depend on the subjective judgment of inspectors, it is hard to ensure their objectiveness and reliability. This study, therefore, aims to develop a new fire damage diagnosis system (FDDS) based on fuzzy theory that can provide objective and comprehensive evaluation results by considering all of the damage conditions observed from the inspection on RC structural members exposed to fire. In addition, the FDDS was applied to an actual fire-damaged case reported by the Architectural Institute of Japan (AIJ, 2009), and it appears that the proposed method provides a reasonable estimation on the fire damage grade of the fire-damaged RC members