Al2O3 has excellent sintering properties and is important in semiconductor manufacturing processes that require high-temperature resistance and chemical inertness in a plasma environment. In this study, a comprehensive analysis of the chemical characteristics, physical properties, crystal structure, and dispersion stability of three commercially available Al2O3 powders was conducted. The aim was to provide a technological foundation for selecting and utilizing appropriate Al2O3 powders in practical applications. All powders exhibited α-Al2O3 as the main phase, with the presence of beta-phase Na2O-11Al2O3 as the secondary phase. The highest Na+ ion leaching was observed in the aqueous slurry state due to the presence of the secondary phase. Although the average particle size difference among the three powders was not significant, distinct differences in particle size distribution were observed. ALG-1SH showed a broad particle size distribution, P162 exhibited a bimodal distribution, and AES-11 displayed a uniform unimodal distribution. Highconcentration Al2O3 slurries showed differences in viscosity due to ion release when no dispersant was added, affecting the electrical double-layer thickness. Polycarboxylate was found to effectively enhance the dispersion stability of all three powders. In the dispersion stability analysis, ALG-1SH exhibited the slowest sedimentation tendency, as evidenced by the low TSI value, while P162 showed faster precipitation, influenced by the particle size distribution.
In this investigation, samples of the chemical (Hg1-xPbxBa2Ca1.8Mg0.2Cu3O8+δ) were prepared utilizing a solid-state reaction technique with a range of lead concentrations (x = 0.0, 0.05, 0.10, and 0.20). Specimens were pressed at 8 tons per square centimeter and then prepared at 1,138 K in the furnace. The crystalline structure and surface topography of all samples were examined using X-ray diffraction (XRD) and atomic force microscopy (AFM). X-ray diffraction results showed that all of the prepared samples had a tetragonal crystal structure. Also, the results showed that when lead was partially replaced with mercury, an increase in the lead value impacted the phase ratio, and lattice parameter values. The AFM results likewise showed excellent crystalline consistency and remarkable homogeneity during processing. The electrical resistivity was calculated as a function of temperature, and the results showed that all samples had a contagious behavior, as the resistivity decreased with decreasing temperature. The critical temperature was calculated and found to change, from 102, 96, 107, and 119 K, when increasing the lead values in the samples from 0.0 to 0.05, 0.10, and 0.20, respectively.
This study successfully prepared high-porosity aluminosilicate fibrous porous ceramics through vacuum suction filtration using aluminosilicate fiber as the primary raw material and glass powder as binder, with the appropriate incorporation of glass fiber. The effects of the composition of raw materials and sintering process on the structure and properties of the material were studied. The results show that when the content of glass powder reached 20 wt% and the samples were sintered at the temperature of 1,000 °C, strong bonds were formed between the binder phase and fibers, resulting in a compressive strength of 0.63 MPa. When the sintering temperatures were increased from 1,000 °C to 1,200, the open porosity of the samples decreased from 89.08 % to 82.38 %, while the linear shrinkage increased from 1.13 % to 10.17 %. Meanwhile, during the sintering process, a large amount of cristobalite and mullite were precipitated from the aluminosilicate fibers, which reduced the performance of the aluminosilicate fibers and hindered the comprehensive improvement in sample performance. Based on these conditions, after adding 30 wt% glass fiber and being sintered at 1,000 °C, the sample exhibited higher compressive strength (1.34 MPa), higher open porosity (89.13 %), and lower linear shrinkage (5.26 %). The aluminosilicate fibrous porous ceramic samples exhibited excellent permeability performance due to their high porosity and interconnected three-dimensional pore structures. When the samples were filtered at a flow rate of 150 mL/min, the measured pressure drop and permeability were 0.56 KPa and 0.77 × 10-6 m2 respectively.
This research investigated the preparation of activated carbon derived from Krabok (Irvingia malayana) seed shells to improve the quality of crude glycerol obtained during biodiesel production. The activated carbon was prepared using a dry chemical activation method with NaOH, utilizing an innovative biomass incinerator. The results revealed that the resulting KC/AC-two-step exhibited favorable physicochemical adsorption properties, with a high surface area of 758.72 m2/g and an iodine number of 611.10 mg/g. These values meet the criteria of the industrial product standard for activated carbon No. TIS 900-2004, as specified by the Ministry of Industry in Thailand. Additionally, the adsorption efficiency for methylene blue reached an impressive 99.35 %. This developed activated carbon was then used to improve the quality of crude glycerol obtained from biodiesel production. The experimental results showed that the KC/AC-two-step increased the purity of crude glycerol to 73.61 %. In comparison, commercially available activated carbon (C/AC) resulted in a higher crude glycerol purity of 81.19 %, as analyzed by the GC technique. Additionally, the metal content (Zn, Cu, Fe, Pb, Cd, and Na) in purified glycerol using KC/AC-two-step was below the standards for heavy metals permitted in food and cosmeceuticals by the Food and Drug Administration of Thailand and the European Committee for Food Contact Materials and Articles. As a result, it can be inferred that Krabok seed shells have favorable properties for producing activated carbon suitable as an adsorbent to enhance crude glycerol purity. Furthermore, the improved crude glycerol from this research has potential for various industrial applications.
Background: Cerebral palsy presents significant challenges in motor function for affected children. While conventional bottom-up approaches are common in physical therapy, there is increasing interest in the efficacy of the top-down approach. Objectives: To investigated the impact of applying the top-down approach in physical therapy for a child diagnosed with cerebral palsy, focusing on functional improvement and quality of life. Design: A single-case study. Methods: The patient was a 15-year-old boy with spastic diplegic cerebral palsy who was entering middle school. Cerebral palsy treatment approach of the top-down method (jumping rope) was used to guide and direct physical therapy. Results: The child improved in muscle strength of lower extremity, gross motor function, participation and self-esteem, but the pattern of his gait seemed to be more severe on tiptoe. When the child participated in a jumping rope class, he was able to do more than 10 jumps. Conclusion: The effectiveness of the top-down approach in enhancing functional outcomes and quality of life in children with cerebral palsy. It highlights the potential of this approach in pediatric physical therapy, warranting further research validation.
Background: Kinesio taping is being applied to improve ankle dorsiflexion in stroke patients. Currently, the elasticity of kinesio taping is applied in various ways. Objectives: To investigated the effect of tibialis anterior kinesio taping elasticity level on gait speed in stroke patients. Design: A randomized cross-over pilot study. Methods: A total of 12 study subjects were allowed to experience three conditions within a single group. The three conditions are strong elastic taping condition, weak elastic taping condition, and non-elastic taping condition. Study subjects were randomly assigned to each condition sequentially. For the evaluation, gait variables (cadence, gait speed, stride length) were measured 24 hours after applying the taping appropriate for each condition. Results: The strong elastic taping condition significantly increased gait variables compared to the weak elastic taping and non-elastic taping conditions (P<.05). Weak elastic taping significantly increased gait variables compared to non-elastic taping (P<.05). Conclusion: As tibialis anterior kinesio taping elasticity increased, gait variables significantly improved in stroke patients.
Background: Children with cerebral palsy face challenges in maintaining body stability because of structural and functional defects. Their ability for responsive balance control is diminished. While there exist various trunk stabilization exercises such as Kinetic Link training (KLT) and the Bird-dog posture, there is a notable dearth of research that applies KLT specifically to children with cerebral palsy. Objectives: To investigate the effects of KLT and Bird-dog exercise on gross motor function and balance in children with cerebral palsy. Design: Quaxi-experimental study. Methods: The study participants were randomly divided into two groups: 15 individuals in the KLT group and 15 in the Bird-dog group. General characteristics were examined, and initial measurements of Gross motor function measure (GMFM) and Pediatric balance scale (PBS) were taken prior to the intervention. Each group engaged in KLT exercises and Bird-dog exercises for 20 minutes, three times a week over an 8 week period. Following the completion of the 8 week intervention, secondary measurements of GMFM and PBS were conducted. Results: In the KLT group, both PBS and GMFM showed a significant increase after the intervention compared to before (P<.05). Similarly, in the Bird-dog group, both PBS and GMFM significantly increased after the intervention compared to before (P<.05). There was a significant difference observed in PBS when comparing the pre- and post-intervention changes between the two groups (P<.05), whereas no significant difference was found in GMFM between the groups when comparing the pre- and post-intervention changes (P>.05). Conclusion: The interventions involving KLT and Bird-dog exercises were observed to effectively enhance PBS and GMFM in children with cerebral palsy. Specifically, it was evident that KLT was more beneficial in improving balance abilities compared to Bird-dog exercise.
Background: Most studies targeting stroke patients have confirmed improvements in balance and walking using immersive and non-immersive virtual reality training programs. However, to date, there are not many studies targeting brain activation enhancement for the two training programs. Objectives: The purpose of this study is to investigate the effect of a virtual reality training program on the EEG of stroke patients according to differences in immersion. Design: A randomized controlled trial. Methods: A total of 20 stroke patients, with 10 in an immersive virtual reality training programs group (IVRG) and 10 in a non-virtual reality training programs group (NVRG) were randomly assigned to exercise three times a week for 6 weeks. EEG was measured for 2 minutes using DSI-24. Results: The intra-group difference in relative alpha waves of brain waves was not significant for both groups, and the between-group difference was not significant. Differences in EEG relative beta waves in the experiment group were significant in the Fp1, Fp2, Cz, C3, C4, P3, and O2 in the experiment group, and significant in the Cz and O2 in the control group. As a result of comparing the differences between each group before and after, there was a significant difference in the Fp1 area. Conclusion: Virtual reality training programs based on differences in immersion were found to have a positive effect on EEG. Therefore, it is believed that a virtual reality training program based on differences in immersion can be provided as a clinical intervention method for EEG.
Background: There is a lack of research on sling neurac exercise interventions for craniovertebral angle (CVA), head rotation angle, range of motion (ROM), and neck postural alignment in adults with forward head posture Objectives: To investigate the Immediate effects of sling neurac exercise on craniosacral angulation, ROM, and neck postural alignment in adults with forward head posture. Design: Quaxi-experimental study. Methods: Fifty young adults in their 20s were divided into a sling neurac exercise group (SNEG) and a control group (CG). SNEG conducted sling neurac exercise intervention for one day, and CG did not implement intervention. Craniosacral angulation, ROM, and postural alignment before and after exercise was evaluated for each group. Results: In the sling neurac exercise group (SNEG), CVA, cranial rotation angle (CRA), ROM, and postural alignment improved significantly after intervention (all P<.01). There were no significant differences in the control group (CG) (all P>.05). After the intervention, there were significant differences between the groups in craniosacral angulation, ROM, and postural alignment (all P<.01). Conclusion: The Sling neurac exercise can significantly improve CVA, CRA, ROM, and postural alignment. Therefore, it is suggested to consider sling neurac exercise as an intervention.
Background: Effective trunk stabilization has been a cornerstone in physiotherapy, particularly for individuals with lower back issues. While bridging exercises were traditionally employed for this purpose, there has been a growing interest in their modified versions to optimize therapeutic benefits. Objectives: To investigated the differential effects of traditional and modified bridging exercises, particularly when varying leg support and integrating abduction maneuvers during sling-assisted exercises, on trunk muscle responsiveness. Design: Cross-Sectional study. Methods: A group of twenty participants was subjected to three exercise protocols: Bilateral Limb Bridging (BLB), Single Limb Bridging (SLB), and Single Limb Bridging combined with Hip Abduction (SLBHA). Using Surface Electromyography (EMG), the study captured the activation patterns of the Internal Oblique (IO), Erector Spinae (ES), and Multifidus (MF) muscles. Statistical analysis was conducted using the Kruskal-Wallis test, with post-hoc examination for detailed insights. For data consistency, normalization was executed based on Maximum Voluntary Isometric Contractions, and EMG data interpretation was conducted using the RMS technique. Results: The most prominent variations in muscle activation were identified in the IO muscles on both sides. The left IO displayed marked activation disparities between BLB vs. SLB and SLB vs. SLBHA. Analogous observations were made for the right IO when comparing BLB to SLBHA and BLB to SLB. Conversely, ES and MF muscle activations remained consistent across the different exercises. Conclusion: Modified bridge exercises with sling-assisted leg supports with abduction can selectively activate IO muscles, with a noticeable asymmetrical effect favoring the left side.
Background: Stroke patients experience a variety of physical problems due to neurological problems, including difficulties with trunk control. Trunk taping is used to improve gait in stroke patients. Objectives: To investigated the immediate effect of thoracic and abdominal elastic taping on gait parameters (the dynamic balance and gait speed) in stroke patients. Design: Quasi experimental study. Methods: A total of 24 study subjects were randomly assigned to the experimental group (thoracic and abdominal taping, 12 people), and the control group (sham taping, 12 people). All subjects had timed up and go (TUG) test and 10 meter walk test (10MWT) measured before and after taping. Results: After taping, the TUG test and 10MWT results were significantly reduced only in the study group (P<.05). The TUG test and 10MWT results of the study group were significantly decreased compared to the control group. Conclusion: The thoracic and abdominal taping was found to improve trunk control in stroke patients, thereby improving dynamic balance and walking speed.
Background: Most non-pharmacological interventions for tension-type headache (TTH) focus on direct intervention in areas associated with headaches, with limited research exploring the indirect effects of interventions utilizing the fascia. Objectives: To investigate the effects of superficial back line (SBL) stretching and head-neck massage interventions on the range of motion (ROM) and neck disability index (NDI) of TTH. Design: Randomized controlled trial. Methods: The study participants were randomly allocated into three groups: SBL stretching group (n=9), head-neck massage group (n=9), and combined group (n=9). Prior to the intervention, measurements were taken for neck flexion ROM, straight leg raising test (SLRT) ROM, and NDI. The intervention consisted of 30-minute sessions conducted twice a week for 8 weeks. The second measurement took place 4 weeks after the intervention, followed by a third measurement conducted after an additional 4 weeks of intervention. Results: Comparing neck flexion ROM within each group, a significant increase was observed in the SBL stretching group after 8 weeks compared to before the intervention (P<.05). Regarding the comparison of SLRT ROM within each group, a significant increase was noted after 8 weeks compared to before the intervention in the SBL stretching, head-neck massage, and combined groups (P<.05). In terms of the comparison of NDI within each group, a significant decrease was observed in all three group after the intervention compared to before the intervention (P<.05). Conclusion: 8-week intervention involving SBL stretching, head-neck massage, and their combined application demonstrated effectiveness in improving neck flexion ROM, SLRT ROM, and the NDI for individuals with TTH.
Background: In community-dwelling elderly individuals, slower gait speed is closely related to the ground reaction force. In the elderly with fall experience, stride length and gait speed, and other gait parameters are closely related to gastrocnemius activation. Objectives: To investigate whether medial gastrocnemius stiffness influences gait parameters in community-dwelling elderly people who experienced falls. Design: Cross sectional study. Methods: A total of 149 community-dwelling older adults were assigned to the faller and non-faller groups. Gait parameters (step length, stride length, step width, cadence, heel and toe ground reaction force, heel and toe contact time), and stiffness of the medial and lateral gastrocnemius and tibialis anterior were measured using shear wave elastography. Results: Elderly fallers had shorter step and stride length, lower cadence and toe ground reaction force and heel contact time, and lower medial gastrocnemius stiffness than non-fallers. In elderly fallers, medial gastrocnemius stiffness was significantly correlated with step and stride length, step width, toe ground reaction force, and heel contact time. Conclusions: Lower medial gastrocnemius stiffness in the elderly fallers decreases gait parameters, which can be a risk factor for falls. Therefore, medial gastrocnemius stiffness is a major factor that may associated gait parameters that can determine the risk of fall in community-dwelling elderly individuals.
Background: Problem-based learning (PBL) is presented as a superior teaching method compared to existing lecture-based learning. Objectives: To analyzed the effectiveness of creative problem-solving competency, class participation, and self-efficacy in physical therapy students after PBL. Design: Questionnaire design. Methods: This study involved 29 physical therapy students and analyzed changes in their creative problem-solving competency, class participation, and self-efficacy and the correlations between these measurement variables before and after PBL on the “Therapeutic Exercise & Practice” subject. Results: PBL in the musculoskeletal exercise therapy-related subject significantly improved class participation and self-efficacy (P<.05) compared to conventional lecture-based learning, but there was no significant difference in creative problem-solving competency. There was also a positive correlation between a higher level of class participation and higher self-efficacy (P<.05). Conclusions: PBL in the “Therapeutic Exercise & Practice” subject in the Department of Physical Therapy can be an effective educational strategy to increase students’ class participation and self-efficacy. Accordingly, instructors in this department should systematically construct the design of PBL curricula to improve the quality of educational content.
Background: This study investigated quadriceps femoris muscle activity by comparing concentric and eccentric contractions with self-selective squat speed. Objectives: Study participants agreed in advance and included 30 male college students in their 20s without musculoskeletal system disease. Design: A randomized controlled trial. Methods: Participants who participated in this study agreed in advance and recruited 30 male college students in their 20s who had no disease with musculoskeletal system to conduct this study. When squatting at a self-selected speed, the subjects were evaluated using one-way ANOVA to compare concentric and eccentric contraction muscle activity. Results: There were significant differences between the rectus femoris, vastus medialis, and vastus lateralis regarding concentric contractions.contractions. There was a significant difference in vastus medialis but no significant difference between rectus femoris and vastus lateralis for eccentric contractions. Conclusion: During concentric contraction, all muscles and eccentric contractions indicated significant improvement in the vastus medialis. Therefore, to minimize knee joint injury and maximize efficient muscle activity, self-selected slow and moderate speeds based on self-selection speed when performing the sit-down motion during a squat and moderate speed with fast motions when performing the standing motion should be considered as high muscle activities.
Background: The Nordic hamstring exercise is effective as a representative exercise for strengthening eccentric contraction that can activate the hamstring at high levels, improve eccentric contraction strength and ability, and significantly reduce injury rates. Objectives: To investigated a comparison with the lunge exercise to determine the effect of the Nordic hamstring exercise on muscle activity and balance ability in a sample of adult amateurs and football players. Design: Randomized controlled trials. Methods: The subjects of the study were stratified samples of 28 professional and amateur football players and two groups (Nordic hamstring group and lunge group) of 14 people each were studied. Surface electromyography using, was performed to measure the hamstring muscle activity, and the good morning exercise was selected as the measurement exercise. For balance ability, the surface area ellipse and length were measured with BioRescue, while for static balance, the posture of closing the eyes and single-limb standing was measured, and for dynamic balance the one-legged squat was measured. Results: The %MVIC of the semitendinosus and the biceps femoris improved in the Nordic hamstring exercise group and showed statistically significant increase (P<.05). The static and dynamic balance improved in the Nordic hamstring exercise group and showed statistically significant decrease (P<.05). Conclusion: The Nordic hamstring exercise can be useful as an exercise to improve the hamstring muscle activity and balance ability of professional and amateur football players.
Background: Hemiparesis not only affects the affected side but also exerts an impact on the unaffected side. Stroke patients endure muscular weakness attributable to hemiparesis, resulting in asymmetry of muscular strength between the paralyzed and non-paralyzed sides. Objectives: To investigate the correlation between lower limb muscle strength asymmetry and functional factors in patients with stroke. Design: A cross-sectional study. Methods: A total of 58 stroke patients participated in this study. After measuring the muscle strength of both lower limbs using manual muscle testing, the asymmetry was calculated. Functional factors such as berg balance scale (BBS), timed up and go (TUG), 10-metre walk (10MW), and modified barthel index (MBI) were measured. Results: The BBS showed positive correlations with hip, knee, and ankle strength asymmetry (P<.05). The TUG showed negative correlations with hip, knee, and ankle strength asymmetry (P<.05). The 10MW showed negative correlations with hip, knee, and ankle strength asymmetry (P<.05). The MBI showed positive correlations only with hip strength asymmetry (P<.05). Conclusion: We were found that there is a more pronounced lower limb muscle strength asymmetry in the lower extremity of stroke patients, which is associated with BBS, TUG, and 10MW.
Background: Chronic back pain not only causes physical discomfort and decreased functionality but also affects emotional well-being, resulting in feelings of anxiety, depression, and other psychological issues. Studies have indicated that cognitive functional therapy and motor control exercises can alleviate chronic low back pain and associated psychological issues. Objectives: To investigated the effect of chronic low back pain on the cognitive functional therapy (CFT) and motor control exercises (MCE). Design: Quaxi-experimental study. Methods: Forty patients with chronic low back pain were randomly assigned and divided into 20 cognitive functional therapy group with motor control exercises group (CFTMG) and 20 patients in motor control exercises group (MCEG). After applying CFT with motor control exercises and motor control exercises for 8 weeks, changes in numeric pain rating scale (NPRS), Oswestry disability index (ODI) and Fear-avoidance beliefs questionnaire (FABQ) were observed. Results: In the CFTMG, statistically significant changes were observed in NPRS, ODI, and FABQ before and after the intervention. In the MCEG, statistically significant changes were observed in VAS and ODI before and after the intervention. Conclusion: The application of CFTM and MCE in patients suffering from chronic low back pain has demonstrated effectiveness in alleviating pain, enhancing back function, and reducing kinesiophobia associated with the condition.
Background: The Nordic hamstring exercise is a closed-chain exercise that effectively activates all lower extremity muscles, but there is a lack of consideration of ankle joint which affects exercise effectiveness. One of the major advantages of the Nordic exercise have been known as strengthening lower extremity extensors. This manifests the exercise increases activities of the ankle plantar flexors as well as hip extensors. Objectives: To investigated the impacts of changes in ankle position on the lower extremity musculature and subjective difficulties during the Nordic hip extension exercise. Design: Cross-sectional study. Methods: Twenty the healthy male participants participated in this study. Participants perform three variations of the Nordic exercises including three ankle positions. Each Nordic exercise was defined as ankle position (neutral, dorsiflexion and plantar flexion). During the Nordic exercise, erector spine (ES), gluteus maximus (GM), biceps femoris (BF), gastrocnemius (GCM) activities and subjective difficulties (Borg RPE score) were measured. Results: Muscular activities of the biceps femoris and gastrocnemius were significantly different among the three ankle conditions, which showed controversial results (P<.05). The biceps femoris activity was significantly higher with the dorsiflexion condition, compared to the others (P<.05). On the other hand, activity of the gastrocnemius was significantly higher with the plantarflexion position compared to the others (P<.05). Conclusion: Present study suggests the ankle positional changes could affect lower muscular activities during the Nordic exercise. Although it is difficult to affirm the causes due to limited data, selective activation of the biceps femoris might accomplish with ankle dorsi flexion and that of the gastrocnemius might accomplish with the ankle plantarflexion during the Nordic exercises.
AA1050/AA6061/AA1050 layered sheet was fabricated by cold roll-bonding process and subsequently T4 and T6 aging-treated. Two commercial AA1050 sheets of 1 mm thickness and one AA6061 sheet of 2 mm thickness were stacked up so that an AA6061 sheet was located between two AA1050 sheets. After surface treatments such as degreasing and wire brushing, they were then roll-bonded to a thickness of 2 mm by cold rolling. The roll-bonded Al sheets were then processed by natural aging (T4) and artificial aging (T6) treatments. The as roll-bonded Al sheets showed a typical deformation structure, where the grains are elongated in the rolling direction. However, after the T4 and T6 aging treatments, the Al sheets had a recrystallized structure consisting of coarse grains in both the AA5052 and AA6061 regions with different grain sizes in each. In addition, the sheets showed an inhomogeneous hardness distribution in the thickness direction, with higher hardness in AA6061 than in AA1050 after the T4 and T6 age treatments. The tensile strength of the T6-treated specimen was higher than that of the T4-treated one. However, the strength-ductility balance was much better in the T4-treated specimen than the T6-treated one. The tensile properties of the Al sheets fabricated in the present study were compared with those in a previous study.