Experimental and Digimat-FE Based Representative Volume Element Analysis of Dye-Mixed Colored Resin and Carbon Fiber.

Recently, the automobile industry has demanded weight reduction, so research on materials is being actively conducted. Among this research, carbon fiber-reinforced composite materials are being studied a lot in the automobile industry due to their excellent mechanical properties, chemical resistance, and heat resistance. However, carbon fiber-reinforced composite materials have disadvantages, in that they are not free from color selection, and have weak interfacial bonding strength. In this study, a colored epoxy resin was prepared by mixing epoxy-which is a thermosetting resin according to the pigment concentration (0.1, 0.3, 0.5, 1.0 wt%)-and curing shrinkage. Thermal expansion characteristics were analyzed and the concentration of 0.5 wt% pigment showed the lowest shrinkage and thermal expansion characteristics. In addition, to measure the interfacial shear strength (IFSS) of the carbon fiber and the colored epoxy resin, the IFSS was obtained by performing a microdroplet debonding test, and the strength of the pigment concentration of 0.5 wt% was reduced to a relatively low level. Through these experiments, it was determined that an epoxy resin in which 0.5 wt% pigment is mixed is the optimal condition. Finally, using the composite material modeling software (Digimat 2020.0), the representative volume element (RVE) of the meso-scale was set, and interfacial properties of carbon fibers and colored epoxy resins were analyzed by interworking with general-purpose finite element analysis software (Abaqus CAE).

The effect of abdominal drawing-in exercise and myofascial release on pain, flexibility, and balance of elderly females.

[Purpose] This study is designed to compare the effects of abdominal drawing-in exercise and myofascial release on pain, flexibility, and balance of elderly females. [Subjects and Methods] Forty elderly females aged 65 or older who had complained of low back pain for three months or longer were selected as the subjects. They were randomly and equally assigned to either an abdominal drawing-in group or a myofascial release group. The subjects conducted exercise three times per week, 40 minutes each time, for eight weeks. As evaluation tools, visual analogue scale for pain, remodified schober test for flexibility, and upright posture with eye opening on hard platform, upright posture with eye closing on hard platform, upright posture with eye opening on soft platform, upright posture with eye closing on soft platform using tetrax for balance were used. [Results] The abdominal drawing-in exercise group saw significant difference in pain and balance after the exercise compared to before the exercise. The myofascial release group saw significant difference in pain and flexibility after exercise compared to before the exercise. [Conclusion] The above study showed that abdominal drawing-in exercise affected elderly females regarding pain and balance and myofascial release influenced their pain and flexibility.

Synthesis and Characterization of Thermally Stable Photocurable Polymer with Cyclohexane Moiety.

Photocurable polymers with high transparency and thermal stability were synthesized by reaction between a commercial epoxy resin (NC9110) containing cyclohexane moiety and various kinds of cinnamic acids such as trans-cinnamic acid (CA), 3-hydroxy-trans-cinnamic acid (HCA) and 4-methoxy-trans-cinnamic acid (MCA). The photocurable polymers were synthesized with equal equivalent weight ratio of epoxy and cinnamate group. The chemical structures of the synthesized polymers were confirmed by 1H-NMR and FT-IR spectroscopies. Optical transmittance and thermal stability of the photocured polymers were investigated using UV-Visible spectroscopy and thermogravimetric analysis (TGA), respectively. It was confirmed that the polymers could form thin films with very smooth surface and could be efficiently cured by UV irradiation. It was also found that the polymer after curing showed a good thermal stability and optical transmittance. There was no significant transmittance change after heat treatment at 250 degrees C for 1 h and showed no noticeable weight loss up to 360 degrees C.

Effects of complex manual therapy on PTSD, pain, function, and balance of male torture survivors with chronic low back pain.

[Purpose] This study aimed to identify the impact of physiotherapy using complex manual therapy as a part of an integrated treatment for sequelae in the musculoskeletal system of torture survivors. [Subjects] This study reviewed 30 male torture survivors presenting with chronic low back pain. They were randomly selected and divided into two groups: an experimental group and a control group. [Methods] For the experimental group, complex manual therapy was performed twice a week for 8 weeks to improve the physical sequelae of patients. Improvement was measured using the PDS-K for Post-traumatic Stress Disorder (PTSD), the Visual Analog Scale (VAS) for pain examination, the Korean Oswestry Disability Index (KODI) for back function assessment, and the Balance System SD as a dynamic balance test. The total period of the intervention for both groups was 8 weeks. [Results] For the experimental group, PDS-K, VAS, KODI, and the dynamic balance test all showed significant improvements after the intervention, which they did not for the control group. In the comparison of the groups, PDS-K, VAS, KODI, and the dynamic balance test all showed significant differences. [Conclusion] Complex manual therapy for torture survivors with chronic low back pain contributes to functional recovery by reducing back pain. The treatment can be considered to have positive effects on sequelae in the musculoskeletal system of torture survivors as they age.

Electrophysiological characteristics according to activity level of myofascial trigger points.

[Purpose] This study compared the differences in electrophysiological characteristics of normal muscles versus muscles with latent or active myofascial trigger points, and identified the neuromuscular physiological characteristics of muscles with active myofascial trigger points, thereby providing a quantitative evaluation of myofascial pain syndrome and clinical foundational data for its diagnosis. [Subjects] Ninety adults in their 20s participated in this study. Subjects were equally divided into three groups: the active myofascial trigger point group, the latent myofascial trigger point group, and the control group. [Methods] Maximum voluntary isometric contraction (MVIC), endurance, median frequency (MDF), and muscle fatigue index were measured in all subjects. [Results] No significant differences in MVIC or endurance were revealed among the three groups. However, the active trigger point group had significantly different MDF and muscle fatigue index compared with the control group. [Conclusion] Given that muscles with active myofascial trigger points had an increased MDF and suffered muscle fatigue more easily, increased recruitment of motor unit action potential of type II fibers was evident. Therefore, electrophysiological analysis of these myofascial trigger points can be applied to evaluate the effect of physical therapy and provide a quantitative diagnosis of myofascial pain syndrome.

The effects of Nordic and general walking on depression disorder patients' depression, sleep, and body composition.

[Purpose] This study examined Nordic walking as an exercise intervention for the elderly with depression. [Subjects] Twenty-four patients who were diagnosed with depression were randomly selected and divided into two groups, an experimental group which performed Nordic walking, and a control group, which performed normal walking. [Methods] Both groups practiced their respective walking exercise for 50 minutes per day, three times a week for eight weeks. To compare the effects of the intervention, psychological factors using the Beck depression inventory and sleep quality was assessed using the Korean version Pittsburgh sleep quality index. Skeletal muscle mass, fat free mass, body mass index, body fat percentage, and basal metabolism were estimated three times by a body composition analyzer, before the intervention, four weeks after the intervention, and eight weeks after the intervention. [Results] There was a significant difference in depression with a main effect of time in both groups. There was also a significant difference in sleep in over time and interaction. The differences over time between the two groups were significant for depression, sleep, and skeletal muscle mass. [Conclusion] The results suggests that Nordic walking has a positive effect on depression and sleeping disorders of the elderly, suggesting that Nordic walking based exercise programs should be developed for the elderly who suffer from depression or a sleeping disorder.

The effects of a neck musculoskeletal intervention on neck pain levels and depression in post-traumatic stress disorder patients.

[Purpose] To identify the effects of a neck intervention on neck pain and depression in patients with post-traumatic stress disorder (PTSD). [Subjects] Thirty-one patients with neck pain and a diagnosis of PTSD were enrolled. [Methods] Neck exercise training was performed with the experimental group and neck self-exercise (using a modification of the McKenzie exercise) was used with the control group. Both groups performed their exercises for 30 minutes at a time, three times per week. To compare the effects of the interventions, the threshold of neck tenderness and depression levels were measured at each period. [Results] The pain threshold of both sides of the trapezius showed a significant difference between the two groups at the three measurement periods. In the experimental group, the threshold increased by 19.7% on the left and 18.3% on the right after the intervention compared to before. Depression levels significantly differed in the experimental group between the three measurements. [Conclusion] This study has important implications for therapeutic strategies, as it provides strong evidence for a method of improving symptoms of neck pain; furthermore, it is effective for subjects with psychological problems such as PTSD.

pn-Heterojunction effects of perylene tetracarboxylic diimide derivatives on pentacene field-effect transistor.

We investigated the heterojunction effects of perylene tetracarboxylic diimide (PTCDI) derivatives on the pentacene-based field-effect transistors (FETs). Three PTCDI derivatives with different substituents were deposited onto pentacene layers and served as charge transfer dopants. The deposited PTCDI layer, which had a nominal thickness of a few layers, formed discontinuous patches on the pentacene layers and dramatically enhanced the hole mobility in the pentacene FET. Among the three PTCDI molecules tested, the octyl-substituted PTCDI, PTCDI-C8, provided the most efficient hole-doping characteristics (p-type) relative to the fluorophenyl-substituted PTCDIs, 4-FPEPTC and 2,4-FPEPTC. The organic heterojunction and doping characteristics were systematically investigated using atomic force microscopy, 2D grazing incidence X-ray diffraction studies, and ultraviolet photoelectron spectroscopy. PTCDI-C8, bearing octyl substituents, grew laterally on the pentacene layer (2D growth), whereas 2,4-FPEPTC, with fluorophenyl substituents, underwent 3D growth. The different growth modes resulted in different contact areas and relative orientations between the pentacene and PTCDI molecules, which significantly affected the doping efficiency of the deposited adlayer. The differences between the growth modes and the thin-film microstructures in the different PTCDI patches were attributed to a mismatch between the surface energies of the patches and the underlying pentacene layer. The film-morphology-dependent doping effects observed here offer practical guidelines for achieving more effective charge transfer doping in thin-film transistors.

Dye-sensitized MoS2 photodetector with enhanced spectral photoresponse.

We fabricated dye-sensitized MoS2 photodetectors that utilized a single-layer MoS2 treated with rhodamine 6G (R6G) organic dye molecules (with an optical band gap of 2.38 eV or 521 nm). The proposed photodetector showed an enhanced performance with a broad spectral photoresponse and a high photoresponsivity compared with the properties of the pristine MoS2 photodetectors. The R6G dye molecules deposited onto the MoS2 layer increased the photocurrent by an order of magnitude due to charge transfer of the photoexcited electrons from the R6G molecules to the MoS2 layer. Importantly, the photodetection response extended to the infrared (λ < 980 nm, which corresponded to about half the energy band gap of MoS2), thereby distinguishing the device performance from that of a pristine MoS2 device, in which detection was only possible at wavelengths shorter than the band gap of MoS2, i.e., λ < 681 nm. The resulting device exhibited a maximum photoresponsivity of 1.17 AW(­1), a photodetectivity of 1.5 × 10(7) Jones, and a total effective quantum efficiency (EQE) of 280% at 520 nm. The device design described here presents a significant step toward high-performance 2D nanomaterial-based photodetector.

The Effect of tDCS on Cognition and Neurologic Recovery of Rats with Alzheimer's Disease.

[Purpose] This study examined the effect of the application of transcranial direct current stimulation (tDCS) on neurologic recovery and cognitive function of rats with Alzheimer-like dementia induced by scopolamine injections. [Subjects] To create a cognition dysfunction model, intraperitoneal injection of scopolamine was given to Sprague-Dawley rats that subsequently received tDCS for 4 weeks. [Methods] Changes in motor behavior were evaluated by conducting an open field test. Acetylcholine content in the cerebral cortex and hippocampus was examined for a biochemical assessment. [Results] With respect to changes in motor behavior, group II showed the most meaningful difference after scopolamine injection, followed by group III. In the biochemical assessment, the results of the examination of acetylcholine content in the tissue of the cerebral cortex and the hippocampus on the 14th and 28th days, respectively, showed the most significant increase in group II, followed by group III. [Conclusion] The above findings confirm that tDCS application after the onset of cognitive dysfunction caused by Alzheimer's disease leads to a positive effect on motor behavior and biochemical changes, and this effect is maintained over a specific period of time.

The effects of abdominal draw-in maneuver and core exercise on abdominal muscle thickness and Oswestry disability index in subjects with chronic low back pain.

The purpose of this study was to effects of abdominal draw-in maneuver and core exercise with 4 weeks using the musculoskeletal ultrasonography on muscle thickness and disability in subjects with low back pain. Twenty patients with nonspecific back pain (abdominal draw-in maneuver group: n= 10, core exercise group: n= 10) were recruited in the study. Both group received exercise intervention 3 times a week for 4weeks. The test were based on muscle thickness (transversus abdominis; Tra, internal oblique; IO and external oblique; EO), disability (Oswestry disability index; ODI) measured immediately before and after intervention. The data was measured by SPSS program 12.0 version and analyzed by Paired t-test and Independent t-test. The following results were obtained. The thickness of IO, EO for both group significantly improved except for muscle thickness of Tra. The ODI were significant difference for both groups. As the results of this study, we suggest that it may be effective method to apply to increase for the thickness of Tra, EO using abdominal draw-in maneuver and thickness of IO using core exercise.

The effects of core stability strength exercise on muscle activity and trunk impairment scale in stroke patients.

The purpose of this study was to examine the effects of core stability-enhancing exercises on the lower trunk and muscle activity of stroke patients. The control group (n = 10) underwent standard exercise therapy, while the experiment group (n =10) underwent both the core stability-enhancing exercise and standard exercise therapy simultaneously. The standard exercise therapy applied to the two groups included weight bearing and weight shifts and joint movements to improve flexibility and the range of motion. The core stability-enhancing exercise was performed 5 times a week for 30 min over a period of 4 weeks in the room where the patients were treated. For all 20 subject, the items measured before the exercise were measured after the therapeutic intervention, and changes in muscle activity of the lower trunk were evaluated. The activity and stability of the core muscles were measured using surface electromyography and the trunk impairment scale (TIS). The mean TIS score and muscle activity of the lower trunk increased in the experiment group significantly after performing the core stability-enhancing exercise (P<0.05). The results of this study show that the core stability-enhancing exercise is effective in improving muscle activity of the lower trunk, which is affected by hemiplegia.

In/Ga-free, inkjet-printed charge transfer doping for solution-processed ZnO.

An In/Ga-free doping method of zinc oxide (ZnO) is demonstrated utilizing a printable charge transfer doping layer (CTDL) based on (3-aminopropyl)triethoxysilane (APS) molecules. The self-assembled APS molecules placed on top of ZnO thin films lead to n-type doping of ZnO and filling shallow electron traps, due to the strong electron-donating characteristics of the amine group in APS molecules. The CTDL doping can tune the threshold voltage and the mobility of the ZnO thin-film transistors (TFTs) as one varies the grafting density of the APS molecules and the thickness of the underneath ZnO thin films. From an optimized condition, high-performance ZnO TFTs can be achieved that exhibit an electron mobility of 4.2 cm(2)/(V s), a threshold voltage of 10.5 V, and an on/off current ratio larger than 10(7). More importantly, the method is applicable to simple inkjet processes, which lead to produce high-performance depletion load ZnO inverters through selective deposition of CTDL on ZnO thin films.