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BACKGROUND: The cranio-cervical flexion exercise and sub-occipital muscle inhibition technique have been used to improve a forward head posture among neck pain patients with straight leg raise (SLR) limitation. However, little is known about the cranio-vertebral angle (CVA) and cervical spine range of motion (CROM) after applying stretching methods to the hamstring muscle. OBJECTIVE: To compare the immediate effects of static stretching and proprioceptive neuromuscular facilitation stretching on SLR, CVA, and CROM in neck pain patients with hamstring tightness. METHODS: 64 subjects were randomly allocated to the static stretching ( n 1 = 32) or proprioceptive neuromuscular facilitation ( n 2 = 32) stretching group. The SLR test was performed to measure the hamstring muscle's flexibility and tightness between the two groups, with CROM and CVA also being measured. The paired t-test was used to compare all the variables within each group before and after the intervention. The independent t-test was used to compare the two groups before and after the stretching exercise. RESULTS: There were no between-group effects for any outcome variables (P > 0.05). However, all SLR, CVA, and CROM outcome variables were significantly improved within-group (P < 0.05). CONCLUSIONS: There were no between-group effects for any outcome variable; however, SLR, CVA, and CROM significantly improved within-group after the one-session intervention in neck pain patients with hamstring tightness. [ABSTRACT FROM AUTHOR]

BACKGROUND: Fibromyalgia is accompanied by symptoms of fatigue, depression, sleep disorders, and physical and mental stress [1]. It is a difficult-to-treat disorder because its exact causes are unknown. OBJECTIVE: This study aimed to examine the effect of progressive muscle relaxation therapy (PMRT) on pain, fatigue, and stress in patients with fibromyalgia syndrome. METHODS: Thirty-seven patients with fibromyalgia syndrome (age: 20–65 years) were randomly allocated to the PMRT group ( n 1 = 18, 2 men and 16 women) or non-PMRT group ( n 2 = 19, 2 men and 17 women). The PMRT group received PMRT twice a week for 8 weeks and the non-PMRT group received conventional physical therapies such as electro-stimulation and heat therapies during this period. The outcome was evaluated before and after 8 week sofintervention using the Visual Analogue Scale, Multidimensional Assessment of Fatigue, Perceived Stress Scale, and measurement of the blood pressure and pulse rate. RESULTS: Pain and fatigue significantly decreased in the PMRT group compared with the non-PMRT group (both P < 0.001). In addition, perceived stress (P < 0.001), systolic blood pressure (P < 0.001), diastolic blood pressure (P < 0.05), and pulse rate (P < 0.001) significantly decreased in the PMRT group compared with the non-PMRT group. CONCLUSIONS: The findings indicate that progressive muscle relaxation therapy is a viable rehabilitative therapy for pain, fatigue, and stress symptoms in patients with fibromyalgia syndrome. [ABSTRACT FROM AUTHOR]

Supplemental digital content is available in the text. Objective: The aims of the study were to investigate the kinetic effects of sit-to-stand training in various foot positions on the coronal plane in patients with strokes and to suggest appropriate exercises. Design: Thirty-six poststroke subjects participated in this study. The subjects performed three sit-to-stand trials in the following foot positions: (a) symmetric foot positioning (symmetric), (b) affected foot placed to the side (asymmetric 1), and (c) and less affected foot placed to the side (asymmetric 2). They were asked to perform sit-to-stand training at a spontaneous velocity and remain standing for 5 secs, whereas the vertical ground reaction force was measured using force platforms. The activation of lower limb muscles was evaluated using surface electromyography, and the peak and mean vertical ground reaction force and weight-bearing symmetry ratio were evaluated using force platforms. Results: Our results showed significant increases in the muscle activation, peak and mean vertical ground reaction force, and weight-bearing symmetry ratio of the lower limbs using the asymmetric 2 strategy (P < 0.05). Conclusions: Our results suggest that sit-to-stand training with the less affected foot placed to the side by the width of the subject's foot may be the most beneficial in the rehabilitation of patients with hemiparetic stroke. [ABSTRACT FROM AUTHOR]

BACKGROUND: Taekkyon, a Korean form of martial arts, has been trained for a long period. However, it is not yet known whether the Taekkyon exercise has better effects on functional mobility or balance in older adults than other types of well-investigated exercise programs such as Tai Chi (TC). OBJECTIVE: This study aimed to compare the effects of TC and Taekkyon exercise programs on the lower-extremity strength, balance, and gait ability of community-dwelling older women as a fall prevention method. METHODS: Community-dwelling older women were randomly allocated into the TC group ( n 1 = 23) and the Taekkyon group ( n 2 = 23). Both groups completed 1 h of either TC or Taekkyon exercises twice weekly for 12 consecutive weeks (24 sessions in total). We measured the Timed Up and Go test (TUG), Functional Reach test (FR), one-leg standing test (OLS), Five Times Sit-to-Stand test (5 × STS), 30 Second Sit-to-Stand test (30 s STS), and spatiotemporal gait parameters (gait velocity, step length, step width, stride time, and cadence) before and after the intervention. RESULTS: Both groups similarly showed statistically significant improvements in balance (TUG, FR, and OLS), lower-extremity strength (5 × STS and 30 s STS), and spatiotemporal gait parameters except for step width (P < 0.05). Moreover, the TC group showed greater improvement in the OLS test than the Taekkyon group (P < 0.05). CONCLUSIONS: The results from this study support the efficacy of the TC and Taekkyon exercise programs at improving mobility in this population of older women. However, this study did not clarify which exercise program is more effective as general balance and mobility training program for older women. [ABSTRACT FROM AUTHOR]

BACKGROUND: Cervical spinal instability often leads to neck pain and forward head posture (FHP). To improve neck pain and FHP, both the suboccipital muscle inhibition (SMI) technique and cranio-cervical flexion exercise (CCFE) have been used. However, little is known regarding the validity of hamstring flexibility in neck pain subjects after CCFE as a treatment index, and comparison between the SMI technique and CCFE for neck pain treatment. OBJECTIVE: This study aimed to determine the short-term effects of SMI technique and CCFE, which represent passive and active exercise programs, respectively, and whether these improve the straight leg raise (SLR) test results, popliteal angle (PA), cranio-vertebral angle (CVA), and cervical range of motion (CROM) and are equally effective in immediate enhancement of such measures in neck pain subjects. METHODS: Twenty subjects with neck pain were randomly allocated to the SMI and CCFE groups (n = 10 each). The outcomes were evaluated via clinical evaluation and SLR, PA, CVA, and CROM measurement before and after intervention. RESULTS: SLR test results, PA, CVA (sitting and standing), and CROM (flexion, extension, lateral flexion, and right and left rotations) after both interventions were significantly higher than those before the interventions (P < 0.05). The SLR test results (left), PA, and CVA (standing) after the SMI technique improved to levels similar to those observed after CCFE. CONCLUSIONS: Both the SMI technique and CCFE improve SLR test results, PA, CVA, and CROM and are equally effective in immediate enhancement of the hamstring flexibility, CVA, and CROM in subjects with neck pain. [ABSTRACT FROM AUTHOR]

BACKGROUND: Many studies have shown asymmetric behavior of the surface and deep layers of spine muscles in scoliosis patients, compared to normal individuals. However, there is a lack of research on the transversus abdominal (TA) muscle, which plays an important role in trunk stabilization. OBJECTIVE: To assess symmetry in subjects with adolescent idiopathic scoliosis (AIS) by measuring the thickness of abdominal muscles, and to investigate characteristic features through a comparative analysis of the data with healthy aged-matched group. METHODS: Subjects consisted of 33 AIS and 32 healthy subjects of similar ages between 11-28 years old. We measured TA, internal abdominal oblique (IO), and external abdominal oblique (EO) muscles were measured using ultrasonography imaging. Three repeat measurements of the thickness of each muscle were performed during rest and contraction. RESULTS: For the healthy subjects, the intra-class correlation coefficients (ICCs) for the muscle thickness measures ranged from 0.70 to 0.99, standard error of measurement (SEM) was 0.38 cm, and minimal detectable change (MDC) was 1.07 cm. The ICCs for the muscle thickness measures in the AIS group ranged from 0.90 to 0.98, SEM was 0.45 cm, and MDC was 1.24 cm. The symmetry of the two groups was compared, and showed significant difference only in TA in AIS patient group (P < 0.01). CONCLUSIONS: In conclusion, treatment should be focused on exercises that emphasize symmetry, to induce normal action of the TA and structural changes in the spine because AIS induces asymmetry in TA, which plays an important role in trunk stability. [ABSTRACT FROM AUTHOR]

An effective and standardized method for applying a tilt table as a supplementary treatment in the early rehabilitation of stroke patients is still missing. The aim of this study was to determine the influence of progressive task-oriented training on the tilt table on the improvement in lower extremity (LE) muscle activation and clinical function in subjects with hemiplegia due to stroke. Thirty-nine subjects with acute stroke were randomly allocated to three groups; control group, tilt table group, and task-oriented training group on the tilt table, with 13 patients, respectively. All of the subjects received the routine therapy for half an hour, and subjects in the experimental groups additionally received training on two different tilt table applications for 20 min a day, five times a week for three weeks. The effect of tilt table applications was assessed using the surface electromyography (EMG) analysis during stepping-like movements on the tilt table for LE muscle activation and clinical scores for function. Our results showed that there was a significantly greater increase in the EMG patterns of the extensors and flexors of the affected leg muscles during flexion and extension movements of both legs and clinical scores in patients undergoing the progressive task-oriented training on the tilt table compared to the other groups. These findings suggest that progressive task-oriented training on the tilt table can improve LE muscle activation and clinical scores of functional performance for early rehabilitation of subjects with acute stroke. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the influence of progressive task-oriented training on a supplementary tilt table on the lower extremity (LE) muscle strength and spatiotemporal parameters of gait in subjects with hemiplegic stroke. Thirty subjects between three and nine months post stroke were included in this study. Thirty subjects were randomly allocated to a control group (CG, n 1 = 10), experimental group I (EG 1 , n 2 = 10), and experimental group II (EG 2 , n 3 = 10). All of the subjects received routine therapy for half an hour, five times a week for three weeks and additionally received training on the following three different tilt table applications for 20 min a day: (1) both knee belts of the tilt table were fastened (CG), (2) only the affected side knee belt of the tilt table was fastened and one-leg standing training was performed using the less-affected LE (EG 1 ), and (3) only the affected side knee belt of the tilt table was fastened and progressive task-oriented training was performed using the less-affected LE (EG 2 ). The effect of tilt table applications was assessed using a hand-held dynamometer for LE muscle strength and GAITRite for spatiotemporal gait data. Our results showed that there was a significantly greater increase in the strength of all LE muscle groups, gait velocity, cadence, and stride length, a decrease in the double limb support period, and an improvement in gait asymmetry in subjects who underwent progressive task-oriented training on a supplementary tilt table compared to those in the other groups. These findings suggest that progressive task-oriented training on a supplementary tilt table can improve the LE muscle strength and spatiotemporal parameters of gait at an early stage of rehabilitation of subjects with hemiplegic stroke. [ABSTRACT FROM AUTHOR]

Background In general, ankle proprioception is most often evaluated by assessing joint position sense and force sense. However, in contrast to observational studies of joint position sense and force sense, no studies have examined the correlations between joint position sense and force sense. Therefore, the objective of this study was to investigate the correlations between joint position sense and force sense in subjects with healthy and functional ankle instability. Methods Of the sixty nine subjects enrolled in the cross-sectional laboratory study, 35 had functional ankle instability and 34 were healthy subjects. Angle reproduction and force matching methods were used to quantify joint position sense and force sense of the ankle proprioception. These methods were also measured by using a flexible twin axis electrogoniometer and linear force, respectively. Three trials were performed at each angle and force. And then, absolute errors were calculated. Findings Significant differences between the functional ankle instability and healthy group were found for absolute errors of plantar flexion, dorsiflexion, inversion, and eversion ( P < 0.05). No significant correlations between the joint position sense and force sense were found in subjects with both healthy, except for absolute errors of the eversion (r = 0.652, P < 0.05, r 2 = 0.425), and functional ankle instability group ( P > 0.05). Interpretation These findings suggest that it could be explained for deficits of ankle proprioception when angle reproduction and force matching tests to quantify joint position sense and force sense were applied and presented at the same time, not individually. [ABSTRACT FROM AUTHOR]

In this study, we aimed to compare the intrarater reliability and validity of muscle thickness measured using ultrasonography (US) and muscle activity via electromyography (EMG) during manual muscle testing (MMT) of the external oblique (EO) and lumbar multifidus (MF) muscles. The study subjects were 30 healthy individuals who underwent MMT at different grades. EMG was used to measure the muscle activity in terms of ratio to maximum voluntary contraction (MVC) and root mean square (RMS) metrics. US was used to measure the raw muscle thickness, the ratio of muscle thickness at MVC, and the ratio of muscle thickness at rest. One examiner performed measurements on each subject in 3 trials. The intrarater reliabilities of the % MVC RMS and raw RMS metrics for EMG and the % MVC thickness metrics for US were excellent (ICC = 0.81–0.98). There was a significant difference between all the grades measured using the % MVC thickness metric ( p < 0.01). Further, this % MVC thickness metric of US showed a significantly higher correlation with the EMG measurement methods than with the others ( r = 0.51–0.61). Our findings suggest that the % MVC thickness determined by US was the most sensitive of all methods for assessing the MMT grade. [ABSTRACT FROM AUTHOR]

Abstract: Ti-doped hematite (α-Ti0.04Fe1.96O3) film grown over patterned α-Cr2O3 buffer layer on α-Al2O3(0001) substrate was characterized with synchrotron X-ray microdiffraction. The film was grown by oxygen plasma assisted molecular beam epitaxy method. The film growth mode was correlated to buffer layer boundary and Ti concentration variation. Epitaxial α-Ti0.04Fe1.96O3 film was formed on bare substrate adjacent to the buffer layer. The epitaxial film was connected laterally to a strain-relaxed epitaxial α-Ti0.04Fe1.96O3 film grown on the buffer layer. On bare α-Al2O3 substrate with diminished Ti concentration only a small portion of α-TixFe1−xO3 film was epitaxial either as coherent to the substrate or strain-relaxed form. [Copyright &y& Elsevier]

Abstract: The atomic-scale structural changes in an α-Fe2O3 (hematite) (0001) surface induced by sulfidation and subsequent oxidation processes were studied by X-ray photoemission spectroscopy, LEED, and X-ray standing wave (XSW) measurements. Annealing the α-Fe2O3(0001) with a H2S partial pressure of 1×10−7 Torr produced iron sulfides on the surface as the sulfur atoms reacted with the substrate Fe ions. The oxidation state of the substrate Fe changed from 3+ to 2+ as a result of the sulfidation. The XSW measured distance of the sulfur atomic-layer from the unrelaxed substrate oxygen layer was 3.16Å. The sulfide phase consisted of three surface domains identified by LEED. Formation of the two-dimensional FeS2 phase with structural parameters consistent with an outermost layer of (111) pyrite has been proposed. Atomic oxygen exposure oxidized the surface sulfide to a sulfate () and regenerated the α-Fe2O3(0001) substrate, which was indicated by a (1×1) LEED pattern and the re-oxidization of Fe to 3+. [Copyright &y& Elsevier]

Abstract: Electronic structures of the vanadium/vanadium-oxide films supported on α-Fe2O3(0001) were studied by using X-ray photoemission spectroscopy. The vanadium films were grown by evaporation of metallic vanadium at room temperature. The as-deposited V had a 3+ oxidation state and the α-Fe2O3(0001) surface was reduced at the initial coverage. After complete reduction of interface iron atoms, metallic V started to grow at a vanadium coverage greater than 2/3 monolayer. The V2O5 film was prepared by exposing the pre-deposited vanadium film to the atomic oxygen at room temperature. Converting to the V2O5 film was accompanied by re-oxidation of the α-Fe2O3 at the interface. The reduction and re-oxidation of interfacial iron manifest electron transfer between the adsorbed vanadium and substrate. [Copyright &y& Elsevier]

Reports on the development of calcium-selective membranes for all-solid-state ion sensors with a highly adhesive cone-component room temperature vulcanizing-type silicone rubber (RTV-1 type SR). Formulation of the membranes; Effect of plasticizer added to the matrix; EMF measurements.

BACKGROUND: The Republic of Korea has become the most rapidly aging society and is anticipated to enter the post-aged society in 2026. As the population ages, demand for senior-friendly products has gradually increased. Under the demands for these circumstances, usability evaluation aimed to make these products more competitive in terms of quality has been perceived as a critical means. In particular, ergonomically wrong-designed products could prove fatal to elderly people. OBJECTIVE: The purpose of the study is to develop qualitative usability evaluation criteria of communication service robot, one of the senior-friendly products, for elderly people. METHODS: To develop the usability testing criteria of a communication service robot for elderly people. The following was carried out: product selection, selection of target product, development of leading indicators, correction by experts, and preliminary evaluation according to the scenario and development of core indicators. For this, a draft questionnaire was developed for the elderly at around age 60. After small group tests and interviews, the experts modified the initial draft to the usability evaluation criteria of communication service robot for elderly people. RESULTS: Development indicators include four subscales: safety, controllability, efficiency, and satisfaction. All the subscales passed the reliability criteria by four groups of elderly people, divided by gender and the familiarity witth smart move devices. CONCLUSIONS: Development indicators cover a wider area of user experiences of the communication service robot and are a good measurement tool to help both the users and developers of the service robot for elderly people. [ABSTRACT FROM AUTHOR]

Background: Psoriasis has a devastating psychological impact on patients' quality of life. However, the relationship between suicidality and psoriasis remains unclear. Objective: This study analysed and compared the risk of suicidality (suicidal ideation, suicide attempt and completed suicide) between patients with psoriasis and the general population. Methods: This nationwide, population‐based, retrospective, cohort study analysed the Korean National Health Insurance Service claim data from 2005 to 2018. Results: The study included 348,439 patients with psoriasis aged over 18 years and with age‐ and sex‐matched controls. The risk of suicidality was higher in the psoriasis group than in the control group [adjusted hazard ratio (aHR) 1.21; 95% confidence interval (CI), 1.18–1.24]. The aHR of suicidality was higher in the psoriatic arthritis group (aHR, 1.46; 95% CI, 1.39–1.54) than in the psoriasis‐alone group (aHR, 1.17; 95% CI, 1.13–1.20). However, the severity of psoriasis and suicidality showed no correlation (mild psoriasis group: aHR, 1.22; 95% CI, 1.18–1.25; moderate‐to‐severe psoriasis group: aHR, 1.16; 95% CI, 1.10–1.23). Conclusion: Patients with psoriasis have an increased risk of suicidality. In particular, the presence of arthritis in patients had a more significant effect on the risk of suicidality. [ABSTRACT FROM AUTHOR]

Intrinsic immunologic disparity of psoriasis itself, along with chronic inflammation and immunomodulatory anti-psoriatic treatments could be associated with increased risk of malignancy. We aimed to estimate the risk of malignancy in patients with psoriasis by treatment modality compared with that in individuals without psoriasis in Korea. We conducted a nationwide cohort study using the claims database of the National Health Insurance Service from January 2005 to December 2018. A total of 255,471 patients with psoriasis, and age- and sex-matched non-psoriasis participants (1:1 ratio) were enrolled. The adjusted hazard ratios (aHRs) [95% confidence intervals (CIs)] for malignancy without nonmelanoma skin cancer (NMSC) were 1.10 [1.08–1.12] in patients with psoriasis, 1.13 [1.00–1.27], 1.05 [0.97–1.13], and 1.24 [0.84–1.83] in phototherapy, non-biologic systemics, and biologics cohort, respectively. Among the non-biologic systemics cohort, patients treated with cyclosporin showed higher risk of malignancy without NMSC (aHR [95% CI], 1.20 [1.04–1.39]). The risk of malignancy without NMSC in patients with psoriasis was higher than that in individuals without psoriasis. Phototherapy and biologics were not associated with significant increase of risk; however, cyclosporin appeared to increase its risk. Dermatologists should be vigilant about this potential risk while managing patients with psoriasis. [ABSTRACT FROM AUTHOR]

Abstract: This study deals with the effect of drainage conditions on porewater pressure distributions and lining stresses in drained tunnels. Firstly, simple closed-form analytical solutions for the steady-state porewater pressure are re-derived within a common theoretical framework for two different boundary conditions (one for zero water pressure and the other for a constant total head) along the tunnel circumference by using the conformal mapping technique. The difference in porewater pressure distributions among the analytical solutions is investigated. The numerical simulation of a drained circular tunnel under the steady-state groundwater flow condition is made to investigate the effect of porewater pressure distributions on lining stresses. Secondly, the case study of the planned South Blue Line Extension subway tunnel under the steady-state groundwater flow condition is performed for four different drainage conditions (sealed, fully-drained with zero water pressure or a constant total head, and invert only-drained) along the tunnel circumference. The effects of different drainage conditions on porewater pressure distributions, flow nets, and lining stresses are investigated. [Copyright &y& Elsevier]

A new diffraction beamline for materials science has been built at the Canadian Light Source synchrotron. The X‐ray source is an in‐vacuum wiggler with a 2.5 T peak magnetic field at 5.2 mm gap. The optical configuration includes a toroidal mirror, a single side‐bounce Bragg monochromator, and a cylindrical mirror, producing a sub‐150 µm vertical × 500 µm horizontal focused beam with a photon energy range of 7–22 keV and a flux of 1012 photons per second at the sample position. Three endstations are currently open to general users, and the techniques available include high‐resolution powder diffraction, small molecule crystallography, X‐ray reflectivity, in situ rapid thermal annealing, and SAXS/WAXS. The beamline design parameters, calculated and measured performance, and initial experimental results are presented to demonstrate the capabilities for materials science. [ABSTRACT FROM AUTHOR]

Diamond coating with sufficient adhesion on WC-Co cutting tools is expected to significantly increase their cutting performance. In order to enhance the coating-substrate interfacial adhesion, Al 2 O 3 and Ta mono-interlayer, Al-Al 2 O 3 , Al-AlN and Al-Ta duplex interlayer systems have been developed in this study. These interlayer materials were prepared using a magnetron sputtering method, and diamond coating were deposited on them using microwave plasma enhanced chemical vapor deposition. Grazing incident X-ray diffraction was carried out to determine the phase components in the Al-Al 2 O 3 and Al-AlN interlayers. Raman spectroscopy and scanning electron microscopy were used to evaluate the quality, morphology and microstructure of the deposited diamond coatings. Rockwell C indentation testing was performed to evaluate the adhesion of the coatings. To elucidate the coating failure mechanism, the compositions around the delaminated spots of diamond coatings after indentation were identified by Energy-dispersive X-ray spectroscopy. The results show that continuous diamond coatings were achieved on Al 2 O 3 , Al-Al 2 O 3 , Al-AlN and Al-Ta interlayered substrates, whereas a graphite layer was still formed with the Ta monolayer accompanied by an easy spallation of diamond coatings. The Al interlayer has played an important role in obtaining high purity diamond by in-situ forming an alumina barrier layer. Especially, the diamond coating deposited with an Al-AlN interlayer demonstrates superior interfacial adhesion in comparison with all the other interlayers. [ABSTRACT FROM AUTHOR]

OBJECTIVE: This study aimed to determine the effect of walking speed on the electromyographic (EMG) activity of the rectus abdominis (RA) and erector spinae (ES) muscles during treadmill high-heeled walking at different shoe heel heights. METHODS: Twenty-five young healthy women volunteered to participate in this study. The subjects performed treadmill walking at speeds of 3 km/h and 6 km/h for 30 seconds under 3 high-heeled conditions: barefoot, 3-cm heels, and 7-cm heels. Surface electromyography (EMG) data were collected from standard sites on the RA and ES muscles during treadmill walking. RESULTS: For all heel heights, the EMG activity of the RA and ES muscles was significantly higher at the 6 km/h speed than at the 3 km/h speed (p < 0.05). Furthermore, EMG activity increased significantly with increasing shoe heel height, regardless of the walking speed (p < 0.05). CONCLUSION: These findings indicate that walking speed and shoe heel height may contribute to the increased activity of the trunk muscle during high-heeled walking. This study provides information for future studies performed with the aim of predicting possible changes in trunk muscle activity during high-heeled walking. [ABSTRACT FROM AUTHOR]

Arsenic (As) distribution in nail clippings from three healthy human subjects was investigated using the microbeam experimental setup of the hard x-ray micro-analysis (HXMA) beamline from the Canadian Light Source (CLS) synchrotron. A pair of toenail and fingernail clippings was collected from each of three subjects (one contributed two fingernail clippings). The fingernail and toenail clippings were embedded in polyester resin and cut in cross-sectional slices with an average thickness of 270 µm. Nine nail clipping cross sections were analyzed from the three subjects. The same method was used to produce five cross sections of nail phantom clippings with concentrations of As ranging from 0 to 20 µg g−1, in increments of 5 µg g−1. These samples were used to produce a calibration line for the As Kα peak. The energy of the x-ray beam was set at 13 keV for optimal excitation of As and the beam size was 28 × 10 µm2. Each sample was analyzed using a point-by-point scanning technique in a 45° beam-sample and 90° beam-detector geometry. The dwelling time was set at 30 s for the human nail clippings and 20 s for the nail phantom clippings, using a step size of 50 µm in both the horizontal and vertical directions for all samples. As concentration for each point was calculated based on the calibration line parameters and the fitted amplitude of the observed As Kα peak. As concentration maps were produced for each nail clipping cross section. The maps show that small regions (<0.1 mm2) with higher As concentrations (>1 µg g−1) are located predominantly in the ventral and dorsal layers of the nail. The results are in agreement with findings reported in a recent study and can be linked to nail histology and keratin structure. [ABSTRACT FROM AUTHOR]

Abstract: Excess aeration to membrane surface is common for controlling membrane fouling in a submerged membrane bioreactor (MBR) system, but significant energy is consumed for excess air production. Therefore, an alternative strategy for membrane fouling control is currently needed. A new configuration of MBR was proposed in this study to control membrane fouling effectively. To reduce biosolids concentration near the membrane surface, the position of the membrane module in MBR was elevated from the bottom to the top in the reactor. This could divide the reactor to two different zones: upper and lower zone. Air was not supplied at the lower zone whereas aeration was given to the upper zone where the membrane filtration was carried out. Biosolids concentration was reduced in the upper zone because the mixed liquor was settled down to the lower zone. Membrane fouling could be lessened in the upper zone due to the reduced biosolids concentration. Therefore, to verify if this new configuration of MBR could mitigate membrane fouling, the effect of changing vertical position of the membrane module in MBR on membrane fouling was investigated. Prior to verification the effect of elevation of membrane module on membrane fouling, influence of MLSS concentration on membrane fouling was investigated first. Transmembrane pressure (TMP) increase became steep as MLSS concentration increased. And the immersed membrane module was elevated from the bottom to the top of the MBR. When the upper membrane was located in the bioreactor, less membrane fouling was observed. This could demonstrate a possibility of new MBR design to control membrane fouling. In addition, reduced dissolved oxygen level in the returned sludge to anoxic tank could increase denitrification efficiency if this configuration is directly applied to biological nutrient removal processes. [Copyright &y& Elsevier]