La1-xBaxMnO3 (x = 0.30, 0.35 and 0.40) samples have been prepared by solid-state reaction method. The X-ray diffraction (XRD) study showed that all the samples crystallized in a rhombohedral structure with an R-3c space group. Variation of the magnetization as a function of the temperature and applied magnetic field was carried out. All the samples revealed ferromagnetic to paramagnetic (FM-PM) phase transition at the Curie temperature TC ~ 342 K. The magnetic entropy change was also studied through examination of the measured magnetic isotherms M(H, T) near TC. The magnetocaloric effect was calculated in terms of the isothermal magnetic entropy change. The maximum entropy change reaches a value of 1.192 J/ kgK under a magnetic field change of 2.5T for the La0.6Ba0.4MnO3 composition. The relative cooling power (RCP) is 79.31 J/ kg for the same applied magnetic field.
Particle morphology change and different experimental condition analysis during composite fabrication process by traditional ball milling with discrete element method (DEM) simulation were investigated. A simulation of the three dimensional motion of balls in a traditional ball mill for research on the grinding mechanism was carried out by DEM simulation. We studied the motion of the balls, the ball behavior energy and velocity; the forces acting on the balls were calculated using traditional ball milling as simulated by DEM. The effect of the operational variables such as the rotational speed, ball material and size on the flow velocity, collision force and total impact energy were analyzed. The results showed that increased rotation speed with interaction impact energy between balls and balls, balls and pots and walls and balls. The rotation speed increases with an increase of the impact energy. Experiments were conducted to quantify the grinding performance under the same conditions. Furthermore, the results showed that ball motion affects the particle morphology, which changed from irregular type to plate type with increasing rotation speed. The evolution was also found to depend on the impact energy increase of the grinding media. These findings are useful to understand and optimize the particle motion and grinding behavior of traditional ball mills.
We report on the fabrication and characterization of a novel Cu2O/CuO heterojunction structure with CuO nanorods embedded in Cu2O thin film as an efficient photocathode for photoelectrochemical (PEC) solar water splitting. A CuO nanorod array was first prepared on an indium-tin-oxide-coated glass substrate via a seed-mediated hydrothermal synthesis method; then, a Cu2O thin film was electrodeposited onto the CuO nanorod array to form an oxide semiconductor heterostructure. The crystalline phases and morphologies of the heterojunction materials were examined using X-ray diffraction and scanning electron microscopy, as well as Raman scattering. The PEC properties of the fabricated Cu2O/CuO heterojunction photocathode were evaluated by photocurrent conversion efficiency measurements under white light illumination. From the observed PEC current density versus voltage (J-V) behavior, the Cu2O/CuO photocathode was found to exhibit negligible dark current and high photocurrent density, e.g. −1.05 mA/cm2 at −0.6 V vs. Hg/HgCl2 in 1 mM Na2SO4 electrolyte, revealing the effective operation of the oxide heterostructure. The photocurrent conversion efficiency of the Cu2O/CuO photocathode was estimated to be 1.27% at −0.6 V vs. Hg/HgCl2. Moreover, the PEC current density versus time (J-T) profile measured at −0.5 V vs. Hg/HgCl2 on the Cu2O/CuO photocathode indicated a 3-fold increase in the photocurrent density compared to that of a simple Cu2O thin film photocathode. The improved PEC performance was attributed to a certain synergistic effect of the bilayer heterostructure on the light absorption and electron-hole recombination processes.
The recent development of electro-optic devices and anticorrosion media has led to the necessity to investigate infrared optical systems with solid-solid interfaces of materials that often have the characteristic of amorphousness. One of the most promising classes of materials for those purposes seems to be the chalcogenide glasses. Chalcogenide glasses, based on the Ge-Sb-Se system, have drawn a great deal of attention because of their use in preparing optical lenses and transparent fibers in the range of 3~12 um. In this study, amorphous Ge-Sb-Se chalcogenide for application in an infrared optical product design and manufacture was prepared by a standard melt-quenching technique. The results of the structural, optical and surface roughness analysis of high purity Ge-Sb-Se chalcogenide glasses are reported after various annealing processes.
In this study, six kinds of low-carbon steel specimens with different ferrite-pearlite microstructures were fabricated by varying the Nb content and the transformation temperature. The microstructural factors of ferrite grain size, pearlite fraction, interlamellar spacing, and cementite thickness were quantitatively measured based on optical and scanning electron micrographs; then, Charpy impact tests were conducted in order to investigate the correlation of the microstructural factors with the impact toughness and the ductile-brittle transition temperature (DBTT). The microstructural analysis results showed that the Nb4 specimens had ferrite grain size smaller than that of the Nb0 specimens due to the pinning effect resulting from the formation of carbonitrides. The pearlite interlamellar spacing and the cementite thickness also decreased as the transformation temperature decreased. The Charpy impact test results indicated that the impact-absorbed energy increased and the ductile-brittle transition temperature decreased with addition of Nb content and decreasing transformation temperature, although all specimens showed ductile-brittle transition behaviour.
In this study, recrystallization behaviors in the two-phase (α+γ) region of micro-alloyed steels such as Base, Nb, TiNbV and CAlN were investigated in terms of flow stress, microstructure and associated grain boundary characteristics. The flow stress of all specimens reached peak stress and gradually decreased, which means that recrystallization or recovery of proeutectoid deformed ferrite and recovery or transformation to ferrite of deformed austenite occurred by thermal activation. The precipitation of carbide or nitride via the addition of micro-alloying elements, because it reduced prior austenite grain size upon austenitization, promoted transformation of austenite to ferrite and increased flow stress. The strain-induced precipitation under deformation in the two-phase region, on the other hand, increased the flow stress when the micro-alloying elements were dissolved during austenitization. The recrystallization of the Nb specimen was more effectively retarded than that of the TiNbV specimen during deformation in the two-phase region.
Background: Functional capacity evaluations (FCEs) are designed to systematically assess the capacity to perform work-related tasks and to determine worker’s ability to return to the previous job following work-related injuries. These evaluations may be rated either by clinician or worker. There has been a lack of consensus between the two scoring methods.
Objects: This study aimed: 1) to confirm if the data are fit to the Rasch rating scale model and 2) to investigate the item-level concordance rate between the ratings of clinician and injured worker of the FCE.
Methods: A cross-sectional study was conducted with a sample (n=124) of a rehabilitation program with the Occupational Rehabilitation Data Base for workers with low back pain. The functional capacity evaluation at admission and discharge was administered to clinicians and workers. The data were analyzed using both classical test theory-based Pearson’s r and intra-class coefficient followed by item-level analysis with Rasch rating scale model.
Results: All items of the FCE, except sitting items rated by clinician at admission and handling items rated by both clinician and worker throughout admission and discharge, were acceptable fit statistics with minor out of ranges for a misfit criterion. This may indicate that the items of the FCE overall fit to the Rasch rating scale model. Few problematic items responding differently to clinician and worker both at admission and discharge were detected with the differential item functioning analysis despite the excellent concordance rate using the two conventional statistics-sitting and handling items at admission and handling item at discharge.
Conclusion: The item-level speculations using Rasch analysis of the FCE demonstrate that the ratings of clinician and self ratings of worker were psychometrically acceptable though there was an apparent discrepancy between the raters both at admission and discharge.
Background: The Pediatric Balance Scale (PBS) and the Fullerton Advanced Balance (FAB) scale were used to assess balance function in patients with balance problem. These multidimensional clinical balance scales provide information about potential risk factors for falls.
Objects: The purpose of this study was to investigate and compare the predictive properties of the PBS and FAB scales relative to fall risk in children with cerebral palsy (CP) using a receiver operating characteristic analysis.
Methods: In total, 49 children with CP (boy=21, girl=28) who were diagnosed with level 1 or 2 according to the Gross Motor Function Classification System participated in this study. The PBS and FAB were performed, and verified cut-off score, sensitivity, specificity, and the area of under the curve (AUC).
Results: In this study, the PBS scale was as a predictive measure of fall risk, but the FAB was not significant in children with CP. A cut-off score of 45.5 points provided optimal sensitivity of .90 and specificity of .69 on the PBS, and a cut-off score of 21.5 points provided optimal sensitivity of .90 and specificity of .62 on the FAB. Both scales showed moderately accurate of AUC with .79 and .76, respectively.
Conclusion: The PBS is a useful screening tool for predicting fall risk in children with cerebral palsy, and those who score 45.5 or lower indicate a high risk for falls and are in need of balance intervention.
Background: The functioning of the serratus anterior (SA) muscle is essential to normal scapulohumeral rhythm during forward flexion (FF) of the shoulder. Also, SA weakness and overuse of the upper trapezius (UT) is observed in patients with shoulder dysfunction and trapezius myalgia. We designed a combination exercise involving FF and scapular protraction with resistance (CFFSP) to activate the SA muscle and to deactivate the UT muscle.
Objects: The purpose of this study was to determine whether or not CFFSP would be more effective in activating the SA muscle than FF alone and FF with scapular protraction (FFP).
Methods: Nineteen subjects (12 men and 7 women) participated in this study and performed FF, FFP, and CFFSP at 120°. Surface electromyography was applied to the SA, UT, and pectoralis major (PM) muscles, as was one-way analysis of variance (ANOVA) with repeated measures. Statistical significance was set at .05. Bonferroni adjustment was used to counteract the problem of multiple comparisons, with a statistical level of significance of .017 (.05/3).
Results: A statistically significant difference was found in relation to the three positions for the SA muscle (p<.001) and the SA/UT ratio (p=.005) using ANOVA. Significantly different results, depending on the position, were also demonstrated using the Bonferroni post-hoc test for the SA muscle (FF=28.27±16.20, FFP=45.66±15.81, and CFFSP=62.4±27.21) and for the SA/UT ratio (FF=3.04±2.14, FFP=3.61±2.38, and CFFSP=5.95±3.01). Significant differences between the three positions was not found regarding the average amplitude of SA/PM muscle ratio (SA/PM: p=.060).
Conclusion: We recommend the use of CFFSP to strengthen the SA muscle at 120°.
Background: Losing balance during locomotive actions becomes an increasing threat to both the community-dwelling elderly and elderly with Parkinson disease (PD). Those with PD may be at a high risk of fall due to particular characteristics during the turn. Turning around during locomotive actions may be one of problematic factors causing losing balance.
Objects: This study is part of a larger study, which in part aims to identify turning strategies, to compare the strategies in the elderly with and without idiopathic PD aged 51 years and older and to distinguish whether the turning strategies can predict the elderly at risk of falls.
Methods: A total of 22 community-dwelling elderlies (10 elderlies with idiopathic PD and 12 healthy elderlies) were investigated for the turning strategies during the timed up and go test.
Results: There were some significant differences between the two groups during turning (p<.05). The idiopathic PD group had a tendency of challenging on taking more number of steps, more time to accomplish and staggering more for the turn relative to the control group.
Conclusion: Taking more number of steps and more time to turn may be useful for distinguishing the characteristics of PD from that of the healthy elderly in turning strategy.
Background: Shoulder stabilization commonly involves two components: the glenohumeral stabilization exercise (GSE) and scapular stabilization exercise (SSE). Despite the fact that the shoulder stabilization has advantageous merit, to our knowledge, only a few studies have compared the superior of the GSE and the SSE.
Objects: The purpose of this study was to assess the effects of GSE in patients with nonspecific shoulder pain.
Methods: Thirty subjects with nonspecific shoulder pain were randomly divided into an experimental group and control group, each with 15 patients. The experimental group used an GSE, whereas the control group did SSE. All subjects were measured in shoulder stability, scapular symmetric alignment, pain, muscle power, and range of motion before and after the intervention.
Results: GSE resulted in significantly better shoulder stability (p=.046, from 8.67±7.54 score to 13.93±9.40) in the experimental group compared with SSE in the control group. However, no significant effects were observed for scapular symmetric alignment including the angles of inferior scapular distance (p=.829) and inferior scapular height difference (p=.735), pain (p=.113), muscle power including shoulder flexion (p=.723) and abduction (p=.897) and range of motion including shoulder flexion (p=.853) and abduction (p=.472).
Conclusion: These findings suggest that GSE may be more effective in increasing the shoulder stability than the SSE in patients with nonspecific shoulder pain, probably through a centralization effect on the shoulder mechanism.
Background: In previous studies regarding flexible pes planus, Foot orthosis, special shoes have been used as interventions for correcting malalignment and intrinsic muscles strengthening exercise have been regarded as interventions for foot function and supporting medial longitudinal arch during walking. However, some recent studies reported that strengthening extrinsic muscles as well as intrinsic muscles is more effective and active intervention for flexible pes planus. In particular, the tibialis posterior muscle of foot extrinsic muscles plays essential roles in maintaining the medial longitudinal arch during dynamic weight bearing and balance. In addition this muscle acts longer than other supination muscles during the stance phase in the gait cycle.
Objects: This study aimed to investigate the effect of foot intrinsic muscle and tibialis posterior muscle strengthening exercise for plantar pressure and dynamic balance in adults with flexible pes planus.
Methods: 16 young flexible pes planus adults (7 males, 9 females) were recruited and were randomized into two groups. The experimental group performed foot intrinsic muscle and tibialis posterior muscle strengthening training, the control group performed only foot intrinsic muscle strengthening training. All groups received strengthening training for 30 minutes five times a week for six weeks.
Results: The experimental group had significantly lower plantar pressure of medial heel area than the control group in stand (p<.05). The experimental group had significantly higher dynamic balance ability than control group (p<.05).
Conclusion: The results of this study provide evidence to suggest that foot intrinsic muscle and tibialis posterior muscle of extrinsic muscle strengthening exercises may improve plantar pressure distribution and dynamic balance ability in adults with flexible pes planus.
Background: Deficiencies in the ability to maintain balance are common in elderly. Augmented feedback such as knowledge of results (KR) can accelerate learning and mastering a motor skill in older people.
Objects: We designed this study to examine whether one session of Wii-Fit game with self-regulated KR is effective for elderly people, and to compare the effect of two different timings of self-regulated KR conditions.
Methods: Thirty-nine community-dwelling elders, not living in hospice care or a nursing home, participated in this study. During acquisition, two groups of volunteers were trained in 10 blocks of a dynamic balancing task under the following 2 conditions, respectively: (a) a pre-trial self-regulated KR (n1=18), or (b) a post-trial self-regulated KR (n2=21). Immediate retention tests and delayed retention tests of balancing performance were administered in 15 minutes and 24 hours following acquisition period, respectively.
Results: In both groups, significant improvements of balancing performances scores were observed during the acquisition period. Regardless of the group, mean of balancing performance scores on retention tests were well-maintained from the final session. There were no significant differences between groups in balancing performance scores during the acquisition period (p>.05); however, the post-trial self-regulated KR group exhibited significantly higher balancing performance scores in both the immediate retention test and delayed retention test than that of the pre-trial self-regulated KR group (p<.05).
Conclusion: Therefore, subjects who regulated their feedback after a dynamic balancing task, during the acquisition period, experienced more efficient motor learning during the retention period than did subjects who regulated their feedback before a dynamic balancing task. Accordingly, in case of presenting the KR of motor learning in clinical settings to elders who reduced dynamic balance abilities, the requesting time of KR is imperative according to self-estimation processes as well as types of KR and practice.
Background: Squatting is one of the best functional exercises to strengthen the quadriceps muscle in independent gait and activities of daily living. Although the use of a gym ball during squat exercise is the most common way of strengthening the vastus medialis oblique (VMO) muscle, published data on this subject are limited.
Objects: The purpose of this study was to compare the sequential muscle activation of the VMO and vastus lateralis (VL) muscles during squat exercise using a gym ball at different knee flexion angles.
Methods: Forty healthy adults were randomly divided into experimental (squat exercise using a gym ball) and control (squat exercise alone) groups, in which squats were performed at 45° and 90° knee flexion. Electromyographic (EMG) activity data were collected over 10 seconds under the 2 angles of knee flexion (45° and 90°).
Results: There was significant group and time interaction effect for VMO and VL muscle activation at 45° knee flexion. This was similarly demonstrated at 90° knee flexion. No significant group main effect and time main effect for VMO and VL muscle activation were noted at 45° knee flexion, respectively. In contrast, there was significant group main effect and time main effect for VMO and VL muscle activation at 90° knee flexion. These significant differences were demonstrated through two-way analysis of variance over repeated measurements, suggesting that the EMG activity of the VMO muscle during squatting with a gym ball showed remarkable improvement compared to that of the VL muscle.
Conclusion: This research suggests that squat exercise using a gym ball may be more beneficial in improving the activity of VMO than of the VL muscle at both 45° and 90° of knee flexion, respectively. We highly recommend squat exercises with a gym ball for selective strengthening of the VMO muscle in knee rehabilitation.
Background: Various methods are used for recovery of knee flexion range of motion (ROM) due to a tightened rectus femoris muscle (RFM) or limited inferior glide of the patella. Stretching methods are common interventions for restoring the tightened RFM length. Also patellar inferior gliding (PIG) technique can recover tightened RFM length too. However, effect of applying the PIG to passive knee flexion (PKF) has not been studied.
Objects: The purpose of this study was to investigate the effect of combining PIG with RFM stretching for improving knee flexion ROM in subjects with RFM tightness.
Methods: Twenty-six subjects with RFM tightness were recruited. Two different methods of knee stretching were tested: 1) PKF during modified Thomas test (MTT) and 2) PKF with PIG during MTT. The passive stretching forces was controlled by hand-held dynamometer. The knee flexion ROM angle was measured by a MTT with ImageJ software. Differences between the conditions with and without PIG were identified with a paired t-test.
Results: The knee flexion ROM was significantly greater for PKF with PIG (114.44±9.33) than for PKF alone (108.97±9.42) (p<.001).
Conclusion: A combination of passive knee flexion exercise and PIG can be more effective than PKF in increasing knee flexion ROM in individuals with RFM tightness.
The purpose of this article was to investigate the effects of Maitland’s transverse movement on change of pain, trunk flexion movement and Cobb’s angle in patient with upper thoracic scoliosis. The subject are 37 years old with chronic low back pain participated in this study and has no experience surgery within the last six months due to back pain. 10 set was applied 10 times on the T3-T5 applied the transverse movement with grade Ⅳ to each segment by skilled physical therapist. Transverse movement was applied convex toward the concave side. Pressure pain threshold was reduced from 4/10 to 2/10. Trunk flexion range that is the distance between the middle finger and floor was increase from 7.3cm to 2cm. Cobb’s angle was decreased from degree 18 to 16. This result demonstrated that the Maitland’s transverse movement was benefit to reduce the pain and Cobb’s angle, and to increase the trunk flexion movement.
The purpose of this study was to determine the effects of music therapy and ball exercise on women experiencing menstrual discomforts, thereby identifying the validity of these methods as interventions against menstrual discomforts, with a particular goal of presenting basic data for clinical use. Twenty university students in their 20s were assigned to two therapy groups in a sequence via simple random sampling; ten subjects attended a ball exercise combined with music therapy group and the other ten subjects attended a music therapy group. Ball exercises were conducted 3 times per week for a total of 12 times, starting from 3 weeks before the expected first day of the menstrual period and ending on the last day of the menstrual period. Similarly, the subjects participated in music therapy by listening to music for 35 minutes per session and 3 sessions per week, starting from 3 weeks before the expected first day of the menstrual period and ending on the last day of the menstrual period. Five out of six categories of menstrual discomforts were significantly decreased in both music therapy and ball exercise, the exception being changes in the autonomic nervous system, while those in the music therapy group showed a significant difference only in the category of behavioral changes. The results of the present study demonstrate that the ball exercise combined with music therapy more effective in improving menstrual discomforts than the music therapy group.
The purpose of this study was to investigate the effect of the screen size of smart devices on the bending angle of the cervical spine. The subjects of this study were 30 healthy adults(15 men and 15 women) who used smartphones and tablet PC(personal computer). The changes in the bending angle of the upper and lower cervical spine were measured in the subjects after they had used a smartphone and a tablet PC for 300 seconds each. To make sure that all subjects began in the same starting position, an angle-measuring instrument was used to set the angles of the ankle, knee, hip, and arm joints to 90 degree. The subjects were asked to keep the trunk straight. They were asked to hold a smartphone in their hand and to bend their neck so that they could look down at the screen. Once they began using the smartphone in this manner, they were free to change their posture. We used a paired t-test to compare the bending angle of the cervical spine on subjects who used smartphones and tablet PC in the longterm and short-term there production error of cervical and the significance level was cervical. The results showed that, when using a smartphone and a tablet PC for 300 seconds, there was no significant difference in the bending angle of the upper cervical spine(p>.05), although there was a significant difference in the bending angle of the lower cervical spine(p<.05).
The purpose of this study was to investigate the effects of strengthening and stretching exercises on forward head angle and static·dynamic balance ability. 21 adults with the forward head posture were participated in this study. Subjects were randomly assigned to strengthening exercise group I(n=11) and stretching exercise group II (n=10) respectively. Each group were underwent six intervention over the period of 2 weeks, each session lasting 30 minutes. During a preliminary examination, forward head angle and static∙dynamic balance were measured, and a post examination was conducted that involved same procedure as preliminary examination. There were significant differences in forward head angle after exercise in both groups. In the strengthening group, center of gravity total sway distances was significantly changed under all conditions. In the stretching group, center of gravity total sway distances was significantly changed when subjects had their eyes open while standing on an foam surface. There were significant changes in center of gravity sway velocities in the strengthening group under all conditions, and the same was true in the stretching group only when the subjects had their eyes open while standing on an foam surface. In the comparison between groups, eyes closed while standing on a firm surface was significantly different. There was a significant difference in dynamic balance of the stretching group when the subjects tilted their bodies forward, and there was a statistically significant difference between groups under the same condition. The results of this study suggest that forward head posture can be corrected through therapeutic exercise, and muscle strengthening exercise more effective in improving static balance of forward head posture more than stretching exercise.
The aim of this study was to investigate the effect of Maitland mobilization and Kaltenborn-Evjenth mobilization on the SLR angle. Subjects randomly divided into Kaltenborn-Evjenth group(n=8) and Maitland group(n=7). The mean height, age, body weight was 176.00±5.10 cm, 22.75±1.83 years, 72.63±10.65 kg respectively in Kaltenborn-Evjenth group. The mean height, age, body weight was 175.00±5.60 cm, 22.29 ±3.68 years, 78.00±12.36 kg respectively in Maitland group. Hip joint accessary movements with Grade Ⅲ or IV were applied depend on the patient’s condition to the restricted direction for 1 minute each set, and performed 5 set in a Maitland group. Hip joint anteroposterior gliding with Grade Ⅲ were applied 60 for 1 minutes each set, and performed 5 set in a Kaltenborn-Evjenth group. The angle of first pain was referred to as P1 and subjects were pointed out that they could not bend the knee anymore, then examiner measure SLR angle. The SLR was significantly increased in the Maitland group compared to the Kaltenborn- Evjenth group after intervention(p<.05). In a within group difference, SLR significantly increased in the both groups(p<.05). These results indicated that Maitland mobilization could be recommended the excellent technique to increase the hip flexion in patient with hip hypo-mobility.