This study aims to investigate the effects of ankle foot orthosis(AFO) on the activities of tibialis anterior(TA), soleus(Sol), rectus femoris(RF) and biceps femoris(BF) during stairs descending. The activities of TA, Sol, RF and BF were initially measured while descending 4 stairs without using AFO. The activities of the same muscles were then measured again while descending 4 stairs while using AFO. Wilcoxon signed-rank tests were used to analyze the results in order to examine the differences between the with using AFO and without using AFO. Although the activities of TA, Sol and RF were relatively lower while using AFO than without using AFO, only the differences in Sol and RF activities were significant(p<0.05). The activity of BF was relatively higher while using AFO compared to the activity of BF observed without using AFO. However, difference was not significant(p>0.05). Conclusion of this study was observed since AFO’s ground reaction force absorption during stairs descending reduced the need to use So and RF that is related to shock absorption. BF activity was increased with AFO than without during standing forward to correct the trunk stability.
c-Fos is known to related to synaptic plasticity and apoptosis in damage from ischemia or external injury. The purpose of this study was to investigate whether needle electrode electrical stimulation(NEES) is effective in increasing the number of c-Fos response cells and c-Fos expression in striatum after global ischemia in rats. There were no treatment and occlusion in the control group, global ischemia(GI) group were no treatment after carotid artery occlusion, and needle electrode electrical stimulation(NEES) group were treated with NEES after GI induced. The number of striatum c-Fos response cells and c-Fos protein expression significantly decreased in the NEES group compared to the GI group after 12, 24, 48 hours. The results of the present study suggest that NEES is ineffective in improving global ischemia in rats and may also be ineffective in the globally ischemic human brain.
The purpose of this study was to investigate the effects of combined wedge on the range of motion in ankle and knee joint, ankle eversion moment and knee adduction moment, and center of pressure excursion of foot for genu varus among adult men during gait. This study was carried out with 10 adult men for genu varus in a motion analysis laboratory in J university. The subjects of the experiment were measured above 5cm width between the knees on contact of both medial malleolus of ankle while standing. The width of their knees in neutral position was measured without the inversion or eversion of the subtalar joint by the investigator. The subjects of the experiment were ten who were conducted randomly for standard insole, insole with 10° lateral on rear foot wedge, insole at 10°lateral on rear foot and 5° medial on fore foot wedge. Before and after intervention, changes on the range of motion in ankle and knee joint, ankle eversion moment and knee adduction moment, and center of pressure excursion were measured. In order to compare analyses among groups; repeated one-way ANOVA and Scheffé post hoc test were used. As a result, combined wedge group was significantly decreased compared to control wedge group in terms of knee varus angle in mid-stance(p<.05). Combined wedge group was significantly decreased compared to lateral wedge group in terms of ankle eversion moment in whole stance(p<.05). Combined wedge group was significantly decreased compared to lateral wedge group in terms of knee adduction moment in whole stance(p<.05). Combined wedge group was significantly decreased compared to lateral wedge in terms of center of pressure excursion in whole stance(p<.05). The results of this study suggest that combined wedge for genu varus decreased ankle eversion moment and knee adduction moment upon center of pressure excursion. We hypothesize that combined wedge may also be effective in the protection excessive ankle pronation.
The purpose of this study was to identify the effects of cervical alignment, pain, and physique to apply proprioceptive neuromuscular facilitation( PNF) techniques in patients with forward head posture (FHP). The subjects of this study were 24 patients diagnosed with FHP. They were randomly divided into two groups: a PNF group(n=12) and a control group(n=12). The intervention was performed a total of 24 times, 30 min a day, six times a week for four weeks. Data on cervical alignment(forward head displacement, FHD), pain(visual analog scale, VAS), and physique(height, weight, and body mass index) were obtained pre- and post-intervention. Two-way repeated measures ANOVA was used to compare the groups and time. For FHD, the VAS, and physique(height and BMI), there was an interaction effect for the groups and time(p<.001, BMI: p<.05) and main effects for time(p<.001, BMI: p<.05). For weight, there were main effects of time(p<.01). For FHD(p<.01) and the VAS(p<.05), there were main effects for the groups. In the PNF group, there were significant improvements in FHD, VAS, and physique. In the control group, there was a significant increase in FHD. The results of this study indicated that PNF intervention using scapular and upper extremity patterns effective in FHP positively. The use of a therapeutic intervention on physique changes may also be effective in improving poor posture and help to better patients’ quality of life.
The purpose of our study was to determine the effect of Maitland orthopedic manual therapy, Silver Spike Point, dietary fiber and gymnastic exercise on the improvement of constipation. Forty patients with constipation participated in the study (Maitland Orthopedic Manual Therapy Group(n=10), Silver Spike Point Therapy Group(n=10), Dietary Fiber Group(n=10) and Gymnastics Exercise Group(n=10)). The assessment scale and weekly bowel frequency were measured before and after the experiment. Assessment scale was significantly increased in Silver Spike Point Therapy, Maitland orthopedic therapy, gymnastic exercise compare to dietary fiber. Weekly bowel frequency was significantly increased in gymnastic exercise compared to dietary fiber. The results of this study suggest that Silver Spike Point Therapy, Maitland orthopedic therapy, gymnastic exercise improve the symptom in patients with constipation.
This study aimed to examine the effects of thoracic cage mobilization on the respiratory function, spinal curve and spinal movement in patients with restrictive lung diseases. The subjects were ten community- dwelling elderly with a restrictive lung diseases when measured using a spirometer(FEV1/FVC≤65%, FVC<80%). They received an intervention over an eight-week period: three times a week and for 30 minutes a day. SPSS for Windows(ver. 19.0) was used to analyze all the collected data. Independent t-tests were used to examine changes before and after the intervention. The study's results showed statistically significant improvement(p<.05) in forced expiratory volume in 1 second(chage rate: .24±.25), thoracic curve(chage rate: -2.50±2.76), lumbar curve(chage rate: -.80±1.32), thoracic flexion(chage rate: 2.10± 1.52), thoracic extension(chage rate: -2.00±1.25), lumbar flexion(chage rate: 2.40±3.13) and lumbar extension(chage rate: -1.30±1.42). The results of this study suggest that the thoracic cage mobilization contribute to improve pulmonary function in patients with restrictive lung disease.
The purpose of this study was to investigate the effects of low-intensity cardiac rehabilitation exercise on the cardiac function and the degree of fibrosis in an older white rat model. This study used male Sprague- Dawley white rats that were 50 weeks old. After the acute myocardial infarction induction, Twenty of the rats were randomly allocated into an experimental group and a control group, and each of the groups consisted of 8 rats. In the experimental group, the exercise was conducted for six weeks, 30 minutes a day, five days a week, using a Rotarod treadmill for animals. The degree of myocardial fibrosis was significantly repressed in the experimental group(13.69±1.90%) and in the control group(15.67±1.54%)(p<0.05). However, fractional shortening and ejection fraction did not show a significant difference. The results of this study suggest that cardiac rehabilitation with low intensity treadmill exercise repress the myocardial fibrosis.
The purpose of this study was to examine the effects of sensory stimulation type on the learning of the elderly. The study implemented elderly verbal learning test by evenly dividing a total of 40 elderly people into auditory stimulation followed by visual stimulation group(AVG), visual stimulation followed by auditory stimulation group(VAG), simultaneous visual and auditory stimulation group(SG), and auditory stimulation group(AG). The result are as follows. SSG showed highest results in most of the test, followed by AVG, VAG, and AG. In particular, SG showed a statistically significant difference in immediate recall total score and short delay free recall score(p<.05). In the post-hoc test results of immediate recall total score, SG showed highest score with a statistical significance. AVG showed the second highest score, followed by VAG and AG and all showed a statistic significance(p<.05).In the post-hoc test results of short delay free recall score, SG and AVG showed a statistically significantly higher score than AG(p<.05). The results suggest that simultaneous stimulation of visual and auditory sense is more effective for improving the learning of the elderly people than visual stimulation followed by auditory stimulation or auditory stimulation followed by visual stimulation.
The purpose of this study was to investigate the effects of occipital bone stimulation by cervical stabilizing exercise on the muscle tone, stiffness, ROM, and cervical lordosis in patient with forward head posture( FHP). This study was a case study of a single patient with forward head posture. This study used a ABA' design, A and A' were the baseline phases and B was the intervention phase. The intervention was occipital bone stimulation by cervical stabilization exercise. It was administered once daily for 7 days. The therapist kept hands together, and placed the two index fingers under the subject's occipital bone. The subject performed the chin-in exercise with a maximum isometric contraction for 20 sec.The exercise was implemented by performing the movements 10 times as a set and repeating the set three times. The muscle tone was not significantly changed after intervention. However, the stiffness was decreased and lasted the effect lasted without intervention. The cervical flexion angle was increased, but the cervical extension angle was not significantly changed after the intervention. The left and right lateral flexion angles were increased and the effect lasted without any intervention. However, the left and right rotation angles were significantly changed after the intervention. Cervical lordosis increased not from 37° to 41° after the intervention. These results suggest that occipital bone stimulation by cervical stabilizing exercise had a positive effect on cervical stiffness, flexion and lateral flexion ROM, and lordosis in a patient with forward head posture.
Dy3+ and Eu3+-codoped SrWO4 phosphor thin films were deposited on sapphire substrates by radio frequency magnetron sputtering by changing the growth and thermal annealing temperatures. The results show that the structural and optical properties of the phosphor thin films depended on the growth and thermal annealing temperatures. All the phosphor thin films, irrespective of the growth or the thermal annealing temperatures, exhibited tetragonal structures with a dominant (112) diffraction peak. The thin films deposited at a growth temperature of 100 oC and a thermal annealing temperature of 650 oC showed average transmittances of 87.5% and 88.4% in the wavelength range of 500-1100 nm and band gap energy values of 4.00 and 4.20 eV, respectively. The excitation spectra of the phosphor thin films showed a broad charge transfer band that peaked at 234 nm, which is in the range of 200-270 nm. The emission spectra under ultraviolet excitation at 234 nm showed an intense emission peak at 572 nm and several weaker bands at 479, 612, 660, and 758 nm. These results suggest that the SrWO4: Dy3+, Eu3+ thin films can be used as white light emitting materials suitable for applications in display and solid-state lighting.
Using the ultrasonic pyrolysis method, spherical SiO2 powders were synthesized from aqueous SiO2 sol as a starting material. The effects of pyrolysis conditions such as reaction temperature, SiO2 sol concentration, and physical properties of precursor were investigated for the morphologies of the resulting SiO2 powders. The particle size, shape, and crystallite size of the synthesized SiO2 powders were demonstrated according to the pyrolysis conditions. Generally, the synthesized SiO2 particles were amorphous phase and showed spherical morphology with a smooth surface. It was revealed that increased crystallite size and decreased spherical SiO2 particle size were obtained with increases of the pyrolysis reaction temperature. Also, quantity of spherical SiO2 particles decreased with the decrease in the concentration and surface tension of the precursor.
SrAl2O4: Eu2+ and Dy3+ phosphorescent phosphors were synthesized using the polymerized complex method. Generally, phosphorescent phosphors synthesized by conventional solid state reaction show a micro-sized particle diameter; thus, this process is restricted to applications such as phosphorescent ink and paint. However, it is possible to synthesize homogeneous multi-component powders with fine particle diameter by wet process such as the polymerized complex method. The characteristics of SrAl2O4: Eu2+ and Dy3+ powders prepared by polymerized complex method with one and two step calcination processes were comparatively analyzed. Temperatures of organic material removal and crystallization were observed through TG-DTA analysis. The crystalline phase and crystallite size of the SrAl2O4: Eu2+ and Dy3+ phosphorescent phosphors were analyzed by XRD. Microstructures and afterglow characteristics of the SrAl2O4: Eu2+ and Dy3+ phosphors were measured by SEM and spectrofluorometry, respectively.
Using current-voltage (I-V) and capacitance-voltage (C-V) measurements, the electrical properties of Au and Cu Schottky contacts to n-Ge were comparatively investigated. Lower values of barrier height, ideality factor and series resistance were obtained for the Au contact as compared to the Cu contact. The values of capacitance showed strong dependence on the bias voltage and the frequency. The presence of an inversion layer at the interface might reduce the intercept voltage at the voltage axis, lowering the barrier height for C-V measurements, especially at lower frequencies. In addition, a higher interface state density was observed for the Au contact. The generation of sputter deposition-induced defects might occur more severely for the Au contact; these defects affected both the I-V and C-V characteristics.
We have investigated a glass-forming region of V2O5- P2O5-ZnO glass and the effects of the addition of modifier oxides (B2O3) to the glass systems as a sealing material to improve the adhesion between the glass frits and a soda lime substrate. Thermal properties and coefficient of thermal expansion were measured using a differential scanning calorimetry, a dilatometer and a hot stage microscopy. Structural changes and interfacial reactions between the glass substrate and the glass frit after sintering (at 400 oC for 1 h) were measured by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and scanning electron microscope. The results showed that the adhesion strength increases as the content of B2O3 at 5 mol% increases because of changes in the structural properties. It seems that the glass structures change with B2O3, and the Si4+ ions from the substrate are diffused to the sealing glass. From these results, we could understand the mechanism of strengthening of the adhesion of soda lime silica substrate by ion-diffusion from the substrate to the glass.
The influence of NiCrAlY bond coating on the adhesion properties of an Fe thermal coating sprayed on an Al substrate was investigated. By applying a bond coat, an adhesion strength of 21MPa was obtained, which was higher than the 15.5MPa strength of the coating without the bond coat. Formation of cracks at the interface of the bond coat and the Al substrate was suppressed by applying the bond coat. Microstructural analysis of the coating interface using EBSD and TEM indicated that the dominant bonding mechanism was mechanical interlocking. Mechanical interlocking without crack defects in the coating interface may improve the adhesion strength of the coating. In conclusion, the use of an NiCrAlY bond coat is an effective method of improving the adhesion properties of thermal sprayed Fe coatings on Al substrates.
The present study deals with the effects of micro-alloying elements such as Ni, V, and Ti on the recrystallization behavior of carbon steels at different strain rates. Eight steel specimens were fabricated by varying the chemical composition and reheating temperature; then, a high-temperature compressive deformation test was conducted in order to investigate the relationship of the microstructure and the recrystallization behavior. The specimens containing micro-alloying elements had smaller prior austenite grain sizes than those of the other specimens, presumably due to the pinning effect of the formation of carbonitrides and AlN precipitates at the austenite grain boundaries. The high-temperature compressive deformation test results indicate that dynamic recrystallization behavior was suppressed in the specimens with micro-alloying elements, particularly at increased strain rate, because of the pinning effect of precipitates, grain boundary dragging and lattice misfit effects of solute atoms, although the strength increased with increasing strain rate.
The aim of this paper is to consider the effect of the manufacturing processes on corrosion and centerline cracking of ancient bronze spoons. The ancient bronze spoons in question were made by several steps of forging, in reheated condition with cast ingots. The manufacturing method is similar to that of the modern spoons. The investigations include observations from light and scanning electron microscopes of the microstructure in terms of the crack propagation. Cracks in the centerline are caused by solute segregation in the center-line region; this solute is solidified in the final stage of bronze spoon manufacture. Centerline cracking is also caused by α phase segregation, accompanied by forged overlapping along the longitudinal direction of the spoons. A vertical stripe with cracks along the centerline of the spoon’s width is formed by folding in the wrought process. The overlapping area causes crack propagation with severe corrosion on the spoon surfaces over a period of a thousand years. The failure mechanisms of ancient bronze spoons may be similar to that of modern spoons, and the estimation of the failure mechanisms of ancient spoons can be appropriate to determine failure causes for such modern spoons.
Geopolymers have many advantages over Portland cement, including energy efficiency, reduced greenhouse gas emissions, high strength at early age and improved thermal resistance. Alkali activated geopolymers made from waste materials such as fly ash or blast furnace slag are particularly advantageous because of their environmental sustainability and low cost. However, their durability and functionality remain subjects for further study. Geopolymer materials can be used in various applications such as fire and heat resistant fiber composites, sealants, concretes, ceramics, etc., depending on the chemical composition of the source materials and the activators. In this study, we investigated the thermal properties and microstructure of fly ash and blast furnace slag based geopolymers in order to develop eco-friendly construction materials with excellent energy efficiency, sound insulation properties and good heat resistance. With different curing times, specimens of various compositions were investigated in terms of compressive strength, X-ray diffraction, thermal property and microstructure. In addition, we investigated changes in X-ray diffraction and microstructure for geopolymers exposed to 1,000 oC heat.
The effect of NaOH concentration on the properties of electrolytic plasma processing (EPP) coating formed on AZ61A Mg alloy is studied. Various types of EPP were employed on magnesium alloy AZ61A in a silicate bath with different concentrations of NaOH additive. Analysis of the composition and structure of the coating layers was carried out using an Xray diffractometer (XRD) and a scanning electron microscope (SEM). The results showed that the oxide coating layer mainly consisted of MgO and Mg2SiO4; its porosity and thickness were highly dependent on the NaOH concentration. The Vickers hardness was over 900 HV for all the coatings. The oxide layer with 3 g/l of NaOH concentration exhibited the highest hardness value (1220 HV) and the lowest wear rate. Potentiodynamic testing of the 3 g/l NaOH concentration showed that this concentration had the highest corrosion resistance value of 2.04 × 105 Ωcm2; however, the corrosion current density value of 5.80 × 10−7 A/cm2 was the lowest such value.
To prepare Mn4+-activated K2TiF6 phosphor, a precipitation method without using hydrofluoric acid (HF) was designed. In the synthetic reaction, to prevent the decomposition of K2MnF6, which is used as a source of Mn4+ activator, NH5F2 solution was adopted in place of the HF solution. Single phase K2TiF6:Mn4+ phosphors were successfully synthesized through the designed reaction at room temperature. To acquire high luminance of the phosphor, the reaction conditions such as the type and concentration of the reactants were optimized. Also, the optimum content of Mn4+ activator was evaluator based on the emission intensity. Photoluminescence properties such as excitation and emission spectrum, decay curve, and temperature dependence of PL intensity were investigated. In order to examine the applicability of this material to a white LED, the electroluminescence property of a pc-WLED fabricated by combining the K2TiF6:Mn4+ phosphor with a 450 nm blue-LED chip was measured.