The Tai Chi in Star Formation

NASA Astrophysics Data System (ADS)

Li, Hua-bai

2017-10-01

Tai Chi, a Chinese martial art developed based on the laws of nature, emphasises how 'to conquer the unyielding with the yielding'. The recent observation of star formation shows that stars result from the interaction between gravity, turbulence and magnetic fields. This interaction again follows the nature rules that inspired Tai Chi. For example, if self-gravity is the force that dominates, the molecular cloud will collapse isotropically, which compresses magnetic field lines. The density of the yielding field lines increases until magnetic pressure reaches the critical value to support the cloud against the gravitational force in directions perpendicular to the field lines (Lorentz force). Then gravity gives way to Lorentz force, accumulating gas only along the field lines till the gas density achieves the critical value to again compress the field lines. The Tai Chi goes on in a self-similar way.

A randomized controlled trial of tai chi for long-term low back pain (TAI CHI): study rationale, design, and methods.

PubMed

Hall, Amanda M; Maher, Chris G; Latimer, Jane; Ferreira, Manuela L; Lam, Paul

2009-05-28

Low back pain persisting for longer than 3 months is a common and costly condition for which many current treatments have low-moderate success rates at best. Exercise is among the more successful treatments for this condition, however, the type and dosage of exercise that elicits the best results is not clearly defined. Tai chi is a gentle form of low intensity exercise that uses controlled movements in combination with relaxation techniques and is currently used as a safe form of exercise for people suffering from other chronic pain conditions such as arthritis. To date, there has been no scientific evaluation of tai chi as an intervention for people with back pain. Thus the aim of this study will be to examine the effects of a tai chi exercise program on pain and disability in people with long-term low back pain. The study will recruit 160 healthy individuals from the community setting to be randomised to either a tai chi intervention group or a wait-list control group. Individuals in the tai chi group will attend 2 tai chi sessions (40 minutes)/week for 8 weeks followed by 1 tai chi session/week for 2 weeks. The wait-list control will continue their usual health care practices and have the opportunity to participate in the tai chi program once they have completed the follow-up assessments. The primary outcome will be bothersomeness of back symptoms measured with a 0-10 numerical rating scale. Secondary outcomes include, self-reports of pain-related disability, health-related quality of life and global perceived effect of treatment. Statistical analysis of primary and secondary outcomes will be based on the intention to treat principle. Linear mixed models will be used to test for the effect of treatment on outcome at 10 weeks follow up. This trial has received ethics approval from The University of Sydney Human Research Ethics Committee. HREC Approval No.10452 This study will be the first trial in this area and the information on its effectiveness will allow

Tai chi and meditation: A conceptual (re)synthesis?

PubMed

Posadzki, Paul; Jacques, Samantha

2009-06-01

The aim of this article is to review the literature on Tai Chi and meditation. A coherent construct is developed that includes a comparative analysis and conceptual synthesis of existing theories. The authors discuss a set of assumptions that justify this synthesis; they also argue that this construct would facilitate greater understanding of Tai Chi from the perspective of meditation. Such synthesis may bring "additional" benefits to Tai Chi practitioners as they could recognize that this mind-body technique holds the essence of meditation. Within the scope of this article, the evidence shows a majority of common features when concerning Tai Chi and meditation. These mutual similarities should be taken into account when performing this type of mind-body medicine by patients and/or therapists. Finally, the authors suggest that this inspiring compilation of movements and mindfulness can be used for practical purposes.

Tai chi/yoga effects on anxiety, heartrate, EEG and math computations.

PubMed

Field, Tiffany; Diego, Miguel; Hernandez-Reif, Maria

2010-11-01

To determine the immediate effects of a combined form of Tai chi/yoga. 38 adults participated in a 20-min Tai chi/yoga class. The session was comprised of standing Tai chi movements, balancing poses and a short Tai chi form and 10 min of standing, sitting and lying down yoga poses. The pre- and post- Tai chi/yoga effects were assessed using the State Anxiety Inventory (STAI), EKG, EEG and math computations. Heartrate increased during the session, as would be expected for this moderate-intensity exercise. Changes from pre to post-session assessments suggested increased relaxation including decreased anxiety and a trend for increased EEG theta activity. The increased relaxation may have contributed to the increased speed and accuracy noted on math computations following the Tai chi/yoga class. Copyright © 2010 Elsevier Ltd. All rights reserved.

Tai Chi/ Yoga Effects on Anxiety, Heartrate, EEG and Math Computations

PubMed Central

Field, Tiffany; Diego, Miguel; Hernandez-Reif, Maria

2010-01-01

Objective To determine the immediate effects of a combined form of tai chi/yoga. Design 38 adults participated in a 20-minute tai chi/yoga class. The session was comprised of standing tai chi movements, balancing poses and a short tai chi form and 10 minutes of standing, sitting and lying down yoga poses. Main outcome measures The pre- and post- tai chi/ yoga effects were assessed using the State Anxiety Inventory (STAI), EKG, EEG and math computations. Results Heartrate increased during the session, as would be expected for this moderate intensity exercise. Changes from pre to post session assessments suggested increased relaxation including decreased anxiety and a trend for increased EEG theta activity. Conclusions The increased relaxation may have contributed to the increased speed and accuracy noted on math computations following the tai chi/yoga class. PMID:20920810

Teaching Balance with Tai Chi: Strategies for College and Secondary School Instruction.

ERIC Educational Resources Information Center

Chen, David D.; Sherman, Clay P.

2002-01-01

Examines the benefits of incorporating Tai Chi into the secondary and college curriculum to teach balance, discussing: the history and philosophical underpinnings of Tai Chi, principles of Tai Chi movement, health benefits, and teaching Tai Chi in public schools. Tips for instructors include: follow the principles of progression, follow a…

Health benefits of tai chi: What is the evidence?

PubMed

Huston, Patricia; McFarlane, Bruce

2016-11-01

To summarize the evidence on the health benefits of tai chi. A literature review was conducted on the benefits of tai chi for 25 specific conditions, as well as for general health and fitness, to update a 2014 review of systematic reviews. Systematic reviews and recent clinical trials were assessed and organized into 5 different groups: evidence of benefit as excellent, good, fair, or preliminary, or evidence of no direct benefit. During the past 45 years more than 500 trials and 120 systematic reviews have been published on the health benefits of tai chi. Systematic reviews of tai chi for specific conditions indicate excellent evidence of benefit for preventing falls, osteoarthritis, Parkinson disease, rehabilitation for chronic obstructive pulmonary disease, and improving cognitive capacity in older adults. There is good evidence of benefit for depression, cardiac and stroke rehabilitation, and dementia. There is fair evidence of benefit for improving quality of life for cancer patients, fibromyalgia, hypertension, and osteoporosis. Current evidence indicates no direct benefit for diabetes, rheumatoid arthritis, or chronic heart failure. Systematic reviews of general health and fitness benefits show excellent evidence of benefit for improving balance and aerobic capacity in those with poor fitness. There is good evidence for increased strength in the lower limbs. There is fair evidence for increased well-being and improved sleep. There were no studies that found tai chi worsened a condition. A recent systematic review on the safety of tai chi found adverse events were typically minor and primarily musculoskeletal; no intervention-related serious adverse events have been reported. There is abundant evidence on the health and fitness effects of tai chi. Based on this, physicians can now offer evidence-based recommendations to their patients, noting that tai chi is still an area of active research, and patients should continue to receive medical follow-up for any

A Randomized Trial of Tai Chi for Fibromyalgia

PubMed Central

Wang, Chenchen; Schmid, Christopher H.; Rones, Ramel; Kalish, Robert; Yinh, Janeth; Goldenberg, Don L.; Lee, Yoojin; McAlindon, Timothy

2010-01-01

Background Previous research has suggested that tai chi offers a therapeutic benefit in patients with fibromyalgia. Methods We conducted a single-blind, randomized trial of classic Yang-style tai chi as compared with a control intervention consisting of wellness education and stretching for the treatment of fibromyalgia (defined by American College of Rheumatology 1990 criteria). Sessions lasted 60 minutes each and took place twice a week for 12 weeks for each of the study groups. The primary end point was a change in the Fibromyalgia Impact Questionnaire (FIQ) score (ranging from 0 to 100, with higher scores indicating more severe symptoms) at the end of 12 weeks. Secondary end points included summary scores on the physical and mental components of the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36). All assessments were repeated at 24 weeks to test the durability of the response. Results Of the 66 randomly assigned patients, the 33 in the tai chi group had clinically important improvements in the FIQ total score and quality of life. Mean (±SD) baseline and 12-week FIQ scores for the tai chi group were 62.9±15.5 and 35.1±18.8, respectively, versus 68.0±11 and 58.6±17.6, respectively, for the control group (change from baseline in the tai chi group vs. change from baseline in the control group, −18.4 points; P<0.001). The corresponding SF-36 physical-component scores were 28.5±8.4 and 37.0±10.5 for the tai chi group versus 28.0±7.8 and 29.4±7.4 for the control group (between-group difference, 7.1 points; P = 0.001), and the mental-component scores were 42.6±12.2 and 50.3±10.2 for the tai chi group versus 37.8±10.5 and 39.4±11.9 for the control group (between-group difference, 6.1 points; P = 0.03). Improvements were maintained at 24 weeks (between-group difference in the FIQ score, −18.3 points; P<0.001). No adverse events were observed. Conclusions Tai chi may be a useful treatment for fibromyalgia and merits long-term study in

A randomized trial of tai chi for fibromyalgia.

PubMed

Wang, Chenchen; Schmid, Christopher H; Rones, Ramel; Kalish, Robert; Yinh, Janeth; Goldenberg, Don L; Lee, Yoojin; McAlindon, Timothy

2010-08-19

Previous research has suggested that tai chi offers a therapeutic benefit in patients with fibromyalgia. We conducted a single-blind, randomized trial of classic Yang-style tai chi as compared with a control intervention consisting of wellness education and stretching for the treatment of fibromyalgia (defined by American College of Rheumatology 1990 criteria). Sessions lasted 60 minutes each and took place twice a week for 12 weeks for each of the study groups. The primary end point was a change in the Fibromyalgia Impact Questionnaire (FIQ) score (ranging from 0 to 100, with higher scores indicating more severe symptoms) at the end of 12 weeks. Secondary end points included summary scores on the physical and mental components of the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36). All assessments were repeated at 24 weeks to test the durability of the response. Of the 66 randomly assigned patients, the 33 in the tai chi group had clinically important improvements in the FIQ total score and quality of life. Mean (+/-SD) baseline and 12-week FIQ scores for the tai chi group were 62.9+/-15.5 and 35.1+/-18.8, respectively, versus 68.0+/-11 and 58.6+/-17.6, respectively, for the control group (change from baseline in the tai chi group vs. change from baseline in the control group, -18.4 points; P<0.001). The corresponding SF-36 physical-component scores were 28.5+/-8.4 and 37.0+/-10.5 for the tai chi group versus 28.0+/-7.8 and 29.4+/-7.4 for the control group (between-group difference, 7.1 points; P=0.001), and the mental-component scores were 42.6+/-12.2 and 50.3+/-10.2 for the tai chi group versus 37.8+/-10.5 and 39.4+/-11.9 for the control group (between-group difference, 6.1 points; P=0.03). Improvements were maintained at 24 weeks (between-group difference in the FIQ score, -18.3 points; P<0.001). No adverse events were observed. Tai chi may be a useful treatment for fibromyalgia and merits long-term study in larger study populations. (Funded by

Tai Chi and Qi Gong

MedlinePlus

... Iversen MD, McAlindon T, et al. Assessing the comparative effectiveness of tai chi versus physical therapy for knee osteoarthritis: design and rationale for a randomized trial. BMC Complementary ...

Psychosocial effects of Tai Chi exercise on people with rheumatoid arthritis.

PubMed

Waite-Jones, Jennifer M; Hale, Claire A; Lee, Hea-Young

2013-11-01

To investigate the perceived psychosocial effects of participating in taught sessions of Tai Chi on people diagnosed with rheumatoid arthritis (RA). Tai Chi is thought to be psychologically as well as physically beneficial for people with arthritis. This study adopted a qualitative approach to follow-up participants who had previously demonstrated physical and psychological benefits from a specifically modified Tai Chi programme in an attempt to explore perceived psychosocial improvements. Nineteen semi-structured, audio-taped, interviews were carried out with participants who had taken part in, twice weekly, group-based Tai Chi sessions for 12 weeks. Data from transcripts were analysed using thematic analysis. Analysis suggests that participating in shared Tai Chi sessions provides increased awareness of the links between mind and body; reduces anxiety and depression; and improves self-esteem, self-efficacy and motivation. It was particularly striking to find that the highly structured nature of Tai Chi was felt to improve memory and seemed to offer aesthetic experiences through developing graceful, 'fluid' moves rather than the 'jarring' movements often imposed by having RA. Such group sessions were found to provide social support and help improve participants' sense of perspective. Although small scale, this study suggests that Tai Chi has the potential to offer psychosocial benefits for people with RA. Offering Tai Chi alongside traditional treatments for RA could promote psychological health and well-being, help inform clinical decision-making and prove cost-effective. © 2013 John Wiley & Sons Ltd.

Tai chi for upper limb rehabilitation in stroke patients: the patient's perspective.

PubMed

Desrochers, Pascal; Kairy, Dahlia; Pan, Shujuan; Corriveau, Hélène; Tousignant, Michel

2017-06-01

This study aimed at exploring the perceived benefits and drawbacks of practicing tai chi, an alternative therapy that can be implemented in the community, as part of upper-limb rehabilitation following stroke. Semistructured interviews were carried out with participants with chronic stroke (>6 months). The participants took part in 16 tai chi sessions over 8 weeks. Interviews were conducted in person using an interview guide based on the theory of planned behavior (TPB), and a thematic analysis was conducted. Eight interviews were carried out with participants at various stages of motor recovery. Participants perceived a number of physical, functional, and psychological benefits. They found tai chi to be a global exercise, including both physical and mental aspects, and suggested that it can be included as part of rehabilitation for stroke patients. Many participants expressed a desire to continue practicing tai chi after completion of the study because it exceeded their expectations, among other reasons. This study can serve to guide future tai chi interventions and research on tai chi for rehabilitation in terms of the characteristics of the intervention and the various areas to assess in order to measure the overall benefits. IMPLICATIONS FOR REHABILITATION Tai chi was perceived as a good way of integrating various skills learned during rehabilitation. Despite having different functional abilities, all the participants noted various physical, functional, and psychological benefits from participating in the tai chi sessions. Tai chi seems to be a form of exercise that stroke patients would perform more long-term since all the participants in this study expressed the desire to continue practicing tai chi.

Water-based Tai Chi: theoretical benefits in musculoskeletal diseases. Current evidence

PubMed Central

Macías-Hernández, Salvador Israel; Vázquez-Torres, Lucio; Morones-Alba, Juan Daniel; Coronado-Zarco, Roberto; de los Angeles Soria-Bastida, María; Cruz-Medina, Eva; Nava-Bringas, Tania Inés

2015-01-01

Tai Chi is a low-impact and moderate intensity exercise that has shown positive effects in patients with musculoskeletal disorders. Recently have been developed clinical studies on the benefits of Tai Chi techniques combined with hydrotherapy. Both types of treatment include physical training of balance, mobility, strength, coordination and sensory input that could complement each other. This report aims to present the current evidence about the benefits of the combination of water based Tai Chi in musculoskeletal diseases in order to establish whether the combined intervention is better than Tai Chi or hydrotherapy alone. PMID:26171376

Tai Chi Exercise to Improve Non-Motor Symptoms of Parkinson's Disease.

PubMed

Nocera, Joe R; Amano, Shinichi; Vallabhajosula, Srikant; Hass, Chris J

2013-08-20

A substantial number of individuals with Parkinson's disease exhibit debilitating non-motor symptoms that decrease quality of life. To date, few treatment options exist for the non-motor symptomatology related to Parkinson's disease. The goal of this pilot investigation was to determine the effects of Tai Chi exercise on the non-motor symptomology in Parkinson's disease. Twenty-one individuals with Parkinson's disease were enrolled in a Tai Chi intervention (n=15) or a noncontact control group (n=6). Participants assigned to Tai Chi participated in 60-minute Tai Chi sessions three times per week, for 16 weeks. Pre and post measures included indices of cognitive-executive function including visuomotor tracking and attention, selective attention, working memory, inhibition, processing speed and task switching. Additionally, all participants were evaluated on the Parkinson's disease Questionnaire-39 and Tinetti's Falls Efficacy Scale. Results indicated that the Tai Chi training group had significantly better scores following the intervention than the control group on the Parkinson's disease Questionnaire-39 total score as well as the emotional well-being sub score. Trends for improvement were noted for the Tai Chi group on Digits Backwards, Tinetti's Falls Efficacy Scale, and the activities of daily living and communication sub scores of the Parkinson's disease Questionnaire-39. This research provides initial data that supports future studies to definitively establish efficacy of Tai Chi to improve non-motor features of Parkinson's disease.

A comprehensive review of health benefits of qigong and tai chi.

PubMed

Jahnke, Roger; Larkey, Linda; Rogers, Carol; Etnier, Jennifer; Lin, Fang

2010-01-01

Research examining psychological and physiological benefits of Qigong and Tai Chi is growing rapidly. The many practices described as Qigong or Tai Chi have similar theoretical roots, proposed mechanisms of action, and expected benefits. Research trials and reviews, however, treat them as separate targets of examination. This review examines the evidence for achieving outcomes from randomized controlled trials (RCTs) of both. The key words Tai Chi, Taiji, Tai Chi Chuan, and Qigong were entered into electronic search engines for the Cumulative Index for Allied Health and Nursing (CINAHL), psychological literature (PsycINFO), PubMed, Cochrane database, and Google Scholar. STUDY INCLUSION CRITERIA: RCTs reporting on the results of Qigong or Tai Chi interventions and published in peer-reviewed journals from 1993 to 2007. Country, type and duration of activity, number/type of subjects, control conditions, and reported outcomes were recorded for each study. Outcomes related to Qigong and Tai Chi practice were identified and evaluated. Seventy-seven articles met the inclusion criteria. The nine outcome category groupings that emerged were bone density (n = 4), cardiopulmonary effects (n = 19), physical function (n = 16), falls and related risk factors (n = 23), quality of life (n = 17), self-efficacy (n = 8), patient-reported outcomes (n = 13), psychological symptoms (n = 27), and immune function (n = 6). Research has demonstrated consistent, significant results for a number of health benefits in RCTs, evidencing progress toward recognizing the similarity and equivalence of Qigong and Tai Chi.

Tai Chi training reduced coupling between respiration and postural control.

PubMed

Holmes, Matthew L; Manor, Brad; Hsieh, Wan-hsin; Hu, Kun; Lipsitz, Lewis A; Li, Li

2016-01-01

In order to maintain stable upright stance, the postural control system must account for the continuous perturbations to the body's center-of-mass including those caused by spontaneous respiration. Both aging and disease increase "posturo-respiratory synchronization;" which reflects the degree to which respiration affects postural sway fluctuations over time. Tai Chi training emphasizes the coordination of respiration and bodily movements and may therefore optimize the functional interaction between these two systems. The purpose of the project was to examine the effect of Tai Chi training on the interaction between respiration and postural control in older adults. We hypothesized that Tai Chi training would improve the ability of the postural control system to compensate for respiratory perturbations and thus, reduce posturo-respiratory synchronization. Participants were recruited from supportive housing facilities and randomized to a 12-week Tai Chi intervention (n=28; 86 ± 5 yrs) or educational-control program (n=34, 85 ± 6 yrs). Standing postural sway and respiration were simultaneously recorded with a force plate and respiratory belt under eyes-open and eyes-closed conditions. Posturo-respiratory synchronization was determined by quantifying the variation of the phase relationship between the dominant oscillatory mode of respiration and corresponding oscillations within postural sway. Groups were similar in age, gender distribution, height, body mass, and intervention compliance. Neither intervention altered average sway speed, sway magnitude or respiratory rate. As compared to the education-control group, however, Tai Chi training reduced posturo-respiratory synchronization when standing with eyes open or closed (p<0.001). Tai Chi training did not affect traditional parameters of standing postural control or respiration, yet reduced the coupling between respiration and postural control. The beneficial effects of Tai Chi training may therefore stem in part

Tai Chi training reduced coupling between respiration and postural control

PubMed Central

Holmes, Matthew L; Manor, Brad; Hsieh, Wan-hsin; Hu, Kun; Lipsitz, Lewis A; Li, Li

2015-01-01

In order to maintain stable upright stance, the postural control system must account for the continuous perturbations to the body’s center-of-mass including those caused by spontaneous respiration. Both aging and disease increase “posturo-respiratory synchronization;” which reflects the degree to which respiration affects postural sway fluctuations over time. Tai Chi training emphasizes the coordination of respiration and bodily movements and may therefore optimize the functional interaction between these two systems. The purpose of the project was to examine the effect of Tai Chi training on the interaction between respiration and postural control in older adults. We hypothesized that Tai Chi training would improve the ability of the postural control system to compensate for respiratory perturbations and thus, reduce posturo-respiratory synchronization. Participants were recruited from supportive housing facilities and randomized to a 12-week Tai Chi intervention (n=28; 86±5yrs) or educational-control program (n=34, 85±6yrs). Standing postural sway and respiration were simultaneously recorded with a force plate and respiratory belt under eyes-open and eyes-closed conditions. Posturo-respiratory synchronization was determined by quantifying the variation of the phase relationship between the dominant oscillatory mode of respiration and corresponding oscillations within postural sway. Groups were similar in age, gender distribution, height, body mass, and intervention compliance. Neither intervention altered average sway speed, sway magnitude or respiratory rate. As compared to the education-control group, however, Tai Chi training reduced posturo-respiratory synchronization when standing with eyes open or closed (p<0.001). Tai Chi training did not affect traditional parameters of standing postural control or respiration, yet reduced the coupling between respiration and postural control. The beneficial effects of Tai Chi training may therefore stem in part

The psychosocial effect of Tai Chi on nursing home residents.

PubMed

Lee, Linda Y K; Lee, Diana T F; Woo, Jean

2010-04-01

To determine the psychosocial effect of Tai Chi on nursing home residents. Moving into a nursing home usually imposes a certain degree of psychosocial challenge to older people. However, there is limited evidence suggesting a promising intervention that can promote the psychosocial health for this group. Although previous studies suggest that Tai Chi has the potential to enhance psychosocial well-being, existing evidence is deemed scarce and thus imposes a limitation on drawing out conclusions on this matter. Non-equivalent pretest-posttest control group design. A convenience sample of 139 residents from six nursing homes in Hong Kong was recruited for this study. The experimental group (n = 66) participated in a 26-week Tai Chi programme, while the control group (n = 73) continued its normal daily activities. The outcome measures included state self-esteem, the physical and mental component of health-related quality of life, social support network and social support satisfaction. Resident satisfaction was identified as a covariate because it demonstrated significant correlation with the outcome variables and, likewise, showed significant difference between the two study groups at baseline. Doubly multivariate analysis of covariance was performed to examine the effect of the intervention. Results indicate significant Group x Time interactions, with the experimental group experiencing significant improvement in the composite outcome of state self-esteem, the physical component of health-related quality of life and the mental component of health-related quality of life across the 26-week study period [F(6, 131) = 2.61, p = 0.02)]. No significant changes were detected regarding the effect of the Tai Chi programme on social support. Tai Chi practice is beneficial for nursing home residents. Tai Chi has unique characteristics that are particularly suitable in the practice of health exercise for nursing home residents. The inclusion of Tai Chi in residential care

Comparative Effectiveness of Tai Chi Versus Physical Therapy for Knee Osteoarthritis

PubMed Central

Wang, Chenchen; Schmid, Christopher H.; Iversen, Maura D.; Harvey, William F.; Fielding, Roger A.; Driban, Jeffrey B.; Price, Lori Lyn; Wong, John B.; Reid, Kieran F.; Rones, Ramel; McAlindon, Timothy

2016-01-01

Background Few remedies effectively treat long-term pain and disability from knee osteoarthritis. Studies suggest that Tai Chi alleviates symptoms, but no trials have directly compared Tai Chi with standard therapies for osteoarthritis. Objective To compare Tai Chi with standard physical therapy for patients with knee osteoarthritis. Design Randomized, 52-week, single-blind comparative effectiveness trial. (ClinicalTrials.gov: NCT01258985) Setting An urban tertiary care academic hospital. Patients 204 participants with symptomatic knee osteoarthritis (mean age, 60 years; 70% women; 53% white). Intervention Tai Chi (2 times per week for 12 weeks) or standard physical therapy (2 times per week for 6 weeks, followed by 6 weeks of monitored home exercise). Measurements The primary outcome was Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score at 12 weeks. Secondary outcomes included physical function, depression, medication use, and quality of life. Results At 12 weeks, the WOMAC score was substantially reduced in both groups (Tai Chi, 167 points [95% CI, 145 to 190 points]; physical therapy, 143 points [CI, 119 to 167 points]). The between-group difference was not significant (24 points [CI, −10 to 58 points]). Both groups also showed similar clinically significant improvement in most secondary outcomes, and the benefits were maintained up to 52 weeks. Of note, the Tai Chi group had significantly greater improvements in depression and the physical component of quality of life. The benefit of Tai Chi was consistent across instructors. No serious adverse events occurred. Limitation Patients were aware of their treatment group assignment, and the generalizability of the findings to other settings remains undetermined. Conclusion Tai Chi produced beneficial effects similar to those of a standard course of physical therapy in the treatment of knee osteoarthritis. Primary Funding Source National Center for Complementary and Integrative Health of

Upper Limit of Weights in TAI Computation

NASA Technical Reports Server (NTRS)

Thomas, Claudine; Azoubib, Jacques

1996-01-01

The international reference time scale International Atomic Time (TAI) computed by the Bureau International des Poids et Mesures (BIPM) relies on a weighted average of data from a large number of atomic clocks. In it, the weight attributed to a given clock depends on its long-term stability. In this paper the TAI algorithm is used as the basis for a discussion of how to implement an upper limit of weight for clocks contributing to the ensemble time. This problem is approached through the comparison of two different techniques. In one case, a maximum relative weight is fixed: no individual clock can contribute more than a given fraction to the resulting time scale. The weight of each clock is then adjusted according to the qualities of the whole set of contributing elements. In the other case, a parameter characteristic of frequency stability is chosen: no individual clock can appear more stable than the stated limit. This is equivalent to choosing an absolute limit of weight and attributing this to to the most stable clocks independently of the other elements of the ensemble. The first technique is more robust than the second and automatically optimizes the stability of the resulting time scale, but leads to a more complicated computatio. The second technique has been used in the TAI algorithm since the very beginning. Careful analysis of tests on real clock data shows that improvement of the stability of the time scale requires revision from time to time of the fixed value chosen for the upper limit of absolute weight. In particular, we present results which confirm the decision of the CCDS Working Group on TAI to increase the absolute upper limit by a factor of 2.5. We also show that the use of an upper relative contribution further helps to improve the stability and may be a useful step towards better use of the massive ensemble of HP 507IA clocks now contributing to TAI.

Stability and accuracy of International Atomic Time TAI.

NASA Astrophysics Data System (ADS)

Thomas, C.

Since the end of 1992, the quality of the timing data received at the BIPM has rapidly evolved dues to the extensive replacement of older designs of commercial Cs clocks. Consequently, the stability of the reference time scales has improved significantly. This was tested by running modified algorithms over the real clock data collected at the BIPM. Results of different studies are shown here; in particular the implementation of an upper relative contribution, chosen equal to 1.37% for any contributing clock, leads to σy(τ=40 d) = 1.8×10-15. The accuracy of TAI is estimated by the difference between the duration of the TAI scale interval and the SI second as produced on the rotating geoid by primary frequency standards. In this paper, TAI accuracy is evaluated from six primary frequency standards LPTF-FO1, PTB CS1, PTB CS2, PTB CS3, NIST-7 and SU MCsR 102 all corrected in a consistent manner for the gravitational shift and the black-body radiation shift. This led to a mean departure of the TAI scale interval of 1.8×10-14 s over 1995, known with a relative uncertainty of 0.5×10-14 (1σ).

Time Transfer Methodologies for International Atomic Time (TAI)

DTIC Science & Technology

2007-01-01

International Atomic Time (TAI) and Coordinated Universal Time (UTC) involve either GPS or Two Way Satellite Time and Frequency Transfer ( TWSTFT ). This paper...NRCan, provide real-time carrier-phase based time transfer as well [3,4] Beginning in 2000, time-transfer links using TWSTFT replaced some GPS...links as the primary operational link, and currently over half the clocks used for TAI-generation are linked to other sites via a direct TWSTFT link

A Study on How to Breathe Properly When Practicing Tai Chi Chuan

ERIC Educational Resources Information Center

Yang, Hanchun

2011-01-01

When practicing Tai Chi Chuan, proper breath plays an important role in shaping Tai Chi Chuan's style and its fitness value. The paper aims to analyse the postures of Tai Chi Chuan and its breath characteristics. The paper also presents some new insights on how to co-ordinate breath with postures by case studies.

[Effects of long-term Tai Ji Quan exercise on automatic nervous modulation in the elderly].

PubMed

Guo, Feng

2015-03-01

To examine the effects of long-term Tai Ji Quan (Chinnese Traditional Exercise) on automatic nervous modulation in the elders. The 18 subjects from Tai Ji Quan exercise class in Liaoning University of Retired Veteran Cadres were assigned into long-term Tai Ji Quan exercise group including 10 subjects and novice group including 8 subjects. Electrocardiography, respiratory and blood pressure data were collected on the following time points: at rest before Tai Ji Qhuan exercise and 30 min or 60 min after Tai Ji Quan exercise. The subjects at rest state in the long-term Tai Ji Quan exercise group showed higher than the subjects in the novice group in resperitory rate (RR), standard deviations of normal to normal intervals (SDNN), total power (TP), low frequency power (LFP), high frequency power (HFP), normalized high frequency power (nHFP), but lower in LFP/HFP, systolic and diastolic blood pressure, and heart rate. At rest state the respiratory rate of subjects in long-term Tai Ji Quan exercise group was significantly lower than the novices. After Tai Ji Quan exercise, TP, nHFP, LFP/HFP, heart rate and systolic pressure showed significantly changes, and the change level of Tai Ji Quan on these indices was larger in Tai Ji Quan exercise group than that in the novice group. Long-term Tai Ji Quan exercise can improve vagal modulations, and tend to reduce the sympathetic modulations.

[Qualitative research of the elderly real experience of long-term adherence to Tai Chi exercise].

PubMed

Qiao, Xue; Hao, Yu-fang

2012-12-01

To explore the experience of the process of Tai Chi exercise. The study was conducted in a local park in Beijing of China where varying numbers of community members gathered to practice Tai Chi every day. Volunteers meeting the inclusion and exclusion criteria were recruited after signed an informed consent form. In-depth interview and the participatory observation were used to know of the real feeling of practicing Tai Chi. The qualitative data obtained from the interviews were analyzed by using Colaizzi seven-step method to find the subjects. Six volunteers having a long-time Tai Chi exercise were recruited in this qualitative study, and their real experience was summarized in the physiological level, psychological level, social level and cultural level. In the physiological level, Tai Chi improves the health and exercise of Tai Chi assists the elderly to develop good living habits. In the psychological level, Tai Chi practice guides the person to inner peace, relieves tension, improves depressive mood state, and makes the elderly regain self worth. In the social level Tai Chi is a good form of community practice. In the cultural level, Tai Chi roots in yin and yang culture and integrates internal and external exercises. Tai Chi is good for body and mind health and the community of practice is very important for practitioners. Tai Chi gains popularity for its benefits to health and psychological adjustments, and its cultural connotation.

[Effects of tai chi in postmenopausal women with osteoporosis: a systematic review].

PubMed

Chang, Ting-Jung; Ting, Yu-Ting; Sheu, Shei-Lan; Chang, Hsiao-Yun

2014-10-01

Tai chi has been increasingly applied in osteoporosis patients. However, systematic reviews of the efficacy of this practice have been few and of limited scope. This study reviews previous experimental research work using tai chi as an intervention in postmenopausal women with osteoporosis and to appraise the reported research designs used, tai chi methods used, and outcomes. A systematic review method was used to search 14 databases for articles published between January 1980 and July 2013. Searched keywords included: "tai chi," "osteoporosis," and "postmenopausal women". The 2,458 articles initially identified were reduced to 4 valid articles based on considerations of criteria and repeatability. The 4 valid articles used either a randomized clinical trial (RCT) or a controlled clinical trial (CCT). They were further analyzed and synthesized in terms of common variables such as balance, muscle strength, and quality of life. Three of the 4 studies identified significant pretest / posttest differences in physiological aspects of quality of life in participants but did not obtain consistent results in terms of the psychological aspects. While reports identified a significant and positive tai chi effect on balance, they all used different measurements to do so. Only one of the four studies identified significant improvement in muscle strength. Therefore, this review could not identify clear support for the effectiveness of tai chi on balance or muscle strength. This review did not definitively support the positive effects of tai chi on balance, muscle strength, and quality of life in postmenopausal women with osteoporosis. The designs used in the tai chi interventions may be referenced for future studies. We suggest that future studies use data triangulation rather than a single-item tool to validate the research in order to cross-verify the same information. This may strengthen the research and increase the credibility and the validity of related findings.

Do older t'ai chi practitioners have better attention and memory function?

PubMed

Man, David W K; Tsang, William W N; Hui-Chan, Christina W Y

2010-12-01

Cognitive declines are common in older people and can be a major health issue in an aging world. One type of body-mind exercises, t'ai chi, can be a possible means to help maintaining older adults' cognitive abilities, in addition to beneficial effects of physical exercises. The purpose of this study was to investigate whether t'ai chi practitioners had better attention and memory functions than older people with or without regular exercises. A cross-sectional study examining the relationship between t'ai chi practice and age-, gender- and education-similar older peoples' attention and memory functions. Forty-two (42) community-dwelling elderly subjects, aged 60 or older, recruited from t'ai chi clubs in Hong Kong formed the t'ai chi group. Another 49 elderly having regular exercise habits were recruited from community centers for inclusion in the exercise group. A nonexercise group (normal healthy control) consisting of 44 subjects were also recruited by random selection and through contacting local elderly centers. They were also screened by the Modified Barthel Index, Chinese Mini-mental Status Examination, Geriatric Depression Scale, and evaluated by attention tests (Color Trail Form A-1 and 2) and memory tests (including Rivermead Behavioral Memory Test and The Hong Kong List Learning Test). The main finding was that the three groups differed in attention and memory functions, and the t'ai chi group had demonstrated better performance than the other two groups in most subtests. As a causal relationship cannot be assumed in the present cross-sectional study, future research is required to examine how t'ai chi can improve cognitive function using a randomized control trial as well as determining whether t'ai chi practice can lead to better health status among elderly people.

Tai chi for health benefits in patients with multiple sclerosis: A systematic review

PubMed Central

Wang, Huiru; Xiao, ZhongJun; Fang, Qun; Zhang, Mark; Li, Ting; Du, Geng; Liu, Yang

2017-01-01

The aim of this systematic review was to evaluate the existing evidence on the effectiveness and safety of Tai chi, which is critical to provide guidelines for clinicians to improve symptomatic management in patients with multiple sclerosis (MS). After performing electronic and manual searches of many sources, ten relevant peer-reviewed studies that met the inclusion criteria were retrieved. The existing evidence supports the effectiveness of Tai chi on improving quality of life (QOL) and functional balance in MS patients. A small number of these studies also reported the positive effect of Tai chi on flexibility, leg strength, gait, and pain. The effect of Tai chi on fatigue is inconsistent across studies. Although the findings demonstrate beneficial effects on improving outcome measures, especially for functional balance and QOL improvements, a conclusive claim should be made carefully for reasons such as methodological flaws, small sample size, lack of specific-disease instruments, unclear description of Tai chi protocol, unreported safety of Tai chi, and insufficient follow-up as documented by the existing literature. Future research should recruit a larger number of participants and utilize the experimental design with a long-term follow-up to ascertain the benefits of Tai chi for MS patients. PMID:28182629

A Comprehensive Review of Health Benefits of Qigong and Tai Chi

PubMed Central

Jahnke, Roger; Larkey, Linda; Rogers, Carol; Etnier, Jennifer; Lin, Fang

2011-01-01

Objective Research examining psychological and physiological benefits of Qigong and Tai Chi is growing rapidly. The many practices described as Qigong or Tai Chi have similar theoretical roots, proposed mechanisms of action and expected benefits. Research trials and reviews, however, treat them as separate targets of examination. This review examines the evidence for achieving outcomes from randomized controlled trials (RCTs) of both. Data Sources The key words tai chi, taiji, and qigong were entered into electronic search engines for the Cumulative Index for Allied Health and Nursing (CINAHL), Psychological Literature (PsychInfo), PubMed, Cochrane database, and Google Scholar. Study Inclusion Criteria RCTs reporting on the results of Qigong or Tai Chi interventions and published in peer reviewed journals published from 1993–2007 Data Extraction Country, type and duration of activity, number/type of subjects, control conditions, and reported outcomes were recorded for each study. Synthesis Outcomes related to Qigong and Tai Chi practice were identified and evaluated. Results Seventy-seven articles met the inclusion criteria. The 9 outcome category groupings that emerged were: bone density (n=4), cardiopulmonary effects (n=19), physical function (n=16), falls and related risk factors (n=23), Quality of Life (n=17), self-efficacy (n=8), patient reported outcomes (n=13), psychological symptoms (n=27), and immune function (n=6). Conclusions Research has demonstrated consistent, significant results for a number of health benefits in RCTs, evidencing progress toward recognizing the similarity and equivalence of Qigong and Tai Chi. PMID:20594090

Epigenetic Changes in Response to Tai Chi Practice: A Pilot Investigation of DNA Methylation Marks

PubMed Central

Ren, Hua; Collins, Veronica; Clarke, Sandy J.; Han, Jin-Song; Lam, Paul; Clay, Fiona; Williamson, Lara M.; Andy Choo, K. H.

2012-01-01

Tai chi exercise has been shown to improve physiological and psychosocial functions, well-being, quality of life, and disease conditions. The biological mechanisms by which tai chi exerts its holistic effects remain unknown. We investigated whether tai chi practice results in positive epigenetic changes at the molecular level. Design. The DNA methylation profiles of sixty CpG-dinucleotide marks in female tai chi practitioners (N = 237; 45–88 years old) who have been practising tai chi for three or more years were compared with those of age-matched control females (N = 263) who have never practised tai chi. Results. Six CpG marks originating from three different chromosomes reveal a significant difference (P < 0.05) between the two cohorts. Four marks show losses while two marks show gains in DNA methylation with age in the controls. In the tai chi cohort all six marks demonstrate significant slowing (by 5–70%) of the age-related methylation losses or gains observed in the controls, suggesting that tai chi practice may be associated with measurable beneficial epigenetic changes. Conclusions. The results implicate the potential use of DNA methylation as an epigenetic biomarker to better understand the biological mechanisms and the health and therapeutic efficacies of tai chi. PMID:22719790

Role of Tai Chi in the treatment of rheumatologic diseases.

PubMed

Wang, Chenchen

2012-12-01

Rheumatologic diseases (e.g., fibromyalgia, osteoarthritis, and rheumatoid arthritis) consist of a complex interplay between biologic and psychological aspects, resulting in therapeutically challenging chronic conditions to control. Encouraging evidence suggests that Tai Chi, a multi-component Chinese mind-body exercise, has multiple benefits for patients with a variety of chronic disorders, particularly those with musculoskeletal conditions. Thus, Tai Chi may modulate complex factors and improve health outcomes in patients with chronic rheumatologic conditions. As a form of physical exercise, Tai Chi enhances cardiovascular fitness, muscular strength, balance, and physical function. It also appears to be associated with reduced stress, anxiety, and depression, as well as improved quality of life. Thus, Tai Chi can be safely recommended to patients with fibromyalgia, osteoarthritis, and rheumatoid arthritis as a complementary and alternative medical approach to improve patient well-being. This review highlights the current body of knowledge about the role of this ancient Chinese mind-body medicine as an effective treatment of rheumatologic diseases to better inform clinical decision-making for our patients.

Managing cardiovascular risks with Tai Chi in people with coronary artery disease.

PubMed

Park, In Sook; Song, Rhayun; Oh, Kyong Ok; So, Hee Young; Kim, Dal Sook; Kim, Jong Im; Kim, Tae Sook; Kim, Hyun Li; Ahn, Suk Hee

2010-02-01

The paper is a report of the study to determine the effects of the cardiovascular risk management programme with Tai Chi on cardiovascular risks, health behaviours and quality of life in individuals with coronary artery disease. Many eligible patients with coronary artery disease do not participate in programmes for cardiovascular risk management, mainly because of lack of motivation, high cost or limited accessibility. Tai Chi has been introduced by health professionals to promote cardiovascular functioning and quality of life. A quasi-experimental design with a non-equivalent control group was used. Eighty-five people with a mean age of 66 years completed pretest and 6-month follow-up measures in the following three groups: Tai Chi with education (n = 33), Tai Chi only (n = 19) and control (n = 33). Analysis of covariance was used to compare outcome variables with pretest variables as covariates to adjust for baseline differences. The data were collected in 2005-2006. In the Tai-Chi-with-education group there were statistically significant reductions in modifiable cardiovascular risk factors (F = 3.49, P = 0.035) and improvements in health behaviours (F = 6.12, P = 0.003), mental scores (F = 3.96, P = 0.023), and in the role-emotional (F = 7.30, P = 0.001) and vitality (F = 3.81, P = 0.026) dimensions of quality of life. Tai Chi was safely implemented as an alternative form of exercise in a cardiovascular risk management programme. Whether the beneficial effects of Tai Chi in cardiovascular risk management are comparable with those induced by other types of aerobic exercise requires further investigation.

Comparative effectiveness of Tai Chi versus physical therapy for knee osteoarthritis: a randomized trial

USDA-ARS?s Scientific Manuscript database

Background: Few remedies effectively treat long-term pain and disability from knee osteoarthritis. Studies suggest that Tai Chi alleviates symptoms, but no trials have directly compared Tai Chi with standard therapies for osteoarthritis. Objective: To compare Tai Chi with standard physical therapy f...

Tai Chi for People with Visual Impairments: A Pilot Study

ERIC Educational Resources Information Center

Miszko, Tanya A.; Ramsey, Vincent K.; Blasch, Bruce B.

2004-01-01

This pilot study assessed the physical and psychological outcomes of a tai chi exercise program for eight adults with visual impairments. It found that after eight weeks of orientation and mobility training and tai chi practice, the participants' single leg-stance time and total knee flexion work and power improved, as did their frequency of,…

Tai Chi and Postural Stability in Patients with Parkinson's Disease

PubMed Central

Li, Fuzhong; Harmer, Peter; Fitzgerald, Kathleen; Eckstrom, Elizabeth; Stock, Ronald; Galver, Johnny; Maddalozzo, Gianni; Batya, Sara S.

2012-01-01

Background Patients with Parkinson's disease have substantially impaired balance, leading to diminished functional ability and an increased risk of falling. Although exercise is routinely encouraged by health care providers, few programs have been proven effective. Methods We conducted a randomized, controlled trial to determine whether a tailored tai chi program could improve postural control in patients with idiopathic Parkinson's disease. We randomly assigned 195 patients with stage 1 to 4 disease on the Hoehn and Yahr staging scale (which ranges from 1 to 5, with higher stages indicating more severe disease) to one of three groups: tai chi, resistance training, or stretching. The patients participated in 60-minute exercise sessions twice weekly for 24 weeks. The primary outcomes were changes from baseline in the limits-of-stability test (maximum excursion and directional control; range, 0 to 100%). Secondary outcomes included measures of gait and strength, scores on functional-reach and timed up-and-go tests, motor scores on the Unified Parkinson's Disease Rating Scale, and number of falls. Results The tai chi group performed consistently better than the resistance-training and stretching groups in maximum excursion (between-group difference in the change from baseline, 5.55 percentage points; 95% confidence interval [CI], 1.12 to 9.97; and 11.98 percentage points; 95% CI, 7.21 to 16.74, respectively) and in directional control (10.45 percentage points; 95% CI, 3.89 to 17.00; and 11.38 percentage points; 95% CI, 5.50 to 17.27, respectively). The tai chi group also performed better than the stretching group in all secondary outcomes and outperformed the resistance-training group in stride length and functional reach. Tai chi lowered the incidence of falls as compared with stretching but not as compared with resistance training. The effects of tai chi training were maintained at 3 months after the intervention. No serious adverse events were observed. Conclusions

Tai Chi Improves Brain Metabolism and Muscle Energetics in Older Adults.

PubMed

Zhou, Min; Liao, Huijun; Sreepada, Lasya P; Ladner, Joshua R; Balschi, James A; Lin, Alexander P

2018-04-17

Tai Chi is a mind-body exercise that has been shown to improve both mental and physical health. As a result, recent literature suggests the use of Tai Chi to treat both physical and psychological disorders. However, the underlying physiological changes have not been characterized. The aim of this pilot study is to assess the changes in brain metabolites and muscle energetics after Tai Chi training in an aging population using a combined brain-muscle magnetic resonance spectroscopy (MRS) examination. Six healthy older adults were prospectively recruited and enrolled into a 12-week Tai Chi program. A brain 1 H MRS and a muscle 31 P MRS were scanned before and after the training, and postprocessed to measure N-acetylaspartate to creatine (NAA/Cr) ratios and phosphocreatine (PCr) recovery time. Wilcoxon-signed rank tests were utilized to assess the differences between pre- and post-Tai Chi training. A significant within-subject increase in both the NAA/Cr ratios (P = .046) and the PCr recovery time (P = .046) was observed between the baseline and the posttraining scans. The median percentage changes were 5.38% and 16.51% for NAA/Cr and PCr recovery time, respectively. Our pilot study demonstrates significant increase of NAA/Cr ratios in posterior cingulate gyrus and significantly improved PCr recovery time in leg muscles in older adults following short-term Tai Chi training, and thus provides insight into the beneficial mechanisms. Copyright © 2018 The Authors. Journal of Neuroimaging published by Wiley Periodicals, Inc. on behalf of American Society of Neuroimaging.

Tai Chi exercise in improving cardiorespiratory capacity.

PubMed

Thornton, Everard W

2008-01-01

To evaluate evidence relating to effects of Tai Chi on cardiovascular outcomes, with emphasis on randomised control designs. Studies reviewed in 2004 were re-examined, together with more recent controlled trials of Tai Chi relating to cardiovascular outcome. The analysis provided comment on problems associated with randomised control design, including sources of bias in such trials. With a single exception, data support reduction of baseline systolic/diastolic blood pressure (BP). While there may be positive bias in these studies, data are from diverse ethnic groups, different gender, age, and level of functional ability. There are no data relating to BP reactive change to subsequent stressors. Few studies consider potential mediating mechanisms through which Tai Chi may provide these benefits. Caution is advocated in using randomised controlled trials as the only effective type of study. Such designs are difficult to conduct and effective trials are more likely given a better understanding of the mediating mechanism(s) through which benefits may be derived. It is currently unclear how changes in BP are derived. Some data indicate a shift to increased vagal relative to sympathetic dominance and there may be other potential physiological mediators. No study has examined relationships between potential psychological gains such as self-efficacy and BP change, or individual differences in outcomes.

Tai Chi and health-related quality of life in nursing home residents.

PubMed

Lee, Linda Y K; Lee, Diana T F; Woo, Jean

2009-03-01

Health-related quality of life (HRQOL) that is good is regarded as the goal of elderly residential care. However, limited evidence exists indicating a promising intervention that can achieve this goal. The aim of this study is to examine the effect of Tai Chi on HRQOL in nursing home residents. A nonequivalent pretest-posttest control-group design. A convenience sample of 139 residents from six nursing homes in Hong Kong was used. The experimental group (n=66) joined a 26-week Tai Chi program, while the control group (n=73) continued with usual daily activities. The physical and mental components of HRQOL were designated as the dependent variables. Resident satisfaction was considered as a covariate. Doubly multivariate repeated measures analysis of covariance was done to examine the intervention effect. After adjusting for the confounding effect of resident satisfaction, a statistically significant difference (p<0.05) in the physical and mental components of HRQOL between the experimental and control groups was found. Findings showed significant improvement in HRQOL after residents practiced Tai Chi. These investigators contribute additional knowledge about the health benefits of Tai Chi among nursing home residents and indicates support for its use in this population to improve HRQOL. Tai Chi has unique characteristics as a health exercise that is particularly suitable for nursing home residents. The inclusion of Tai Chi exercise in elderly residential care practice is recommended.

Change in perceived psychosocial status following a 12-week Tai Chi exercise programme.

PubMed

Taylor-Piliae, Ruth E; Haskell, William L; Waters, Catherine M; Froelicher, Erika Sivarajan

2006-05-01

This paper reports a study to examine change in psychosocial status following a 12-week Tai Chi exercise intervention among ethnic Chinese people with cardiovascular disease risk factors living in the United States of America. Regular participation in physical activity is associated with protection against cardioavascular disease, and improvements in physical and psychological health. Increasing amounts of scientific evidence suggests that mind-body exercise, such as Tai Chi, are related to improvements in mental health, emotional well-being, and stress reduction. No prior study has examined the effect of a Tai Chi exercise intervention on psychosocial status among people with cardiovascular disease risk factors. This was a quasi-experimental study. Participants attended a 60-minute Tai Chi exercise class three times per week for 12 weeks. Data were collected at baseline, 6 and 12 weeks following the intervention. Psychosocial status was assessed using Chinese versions of Cohen's Perceived Stress Scale, Profile of Mood States, Multidimensional Scale of Perceived Social Support, and Tai Chi exercise self-efficacy. A total of 39 participants, on average 66-year-old (+/-8.3), married (85%), Cantonese-speaking (97%), immigrants participated. The majority were women (69%), with < or =12 years education (87%). Statistically significant improvements in all measures of psychosocial status were found (P < or = 0.05) following the intervention. Improvement in mood state (eta2 = 0.12), and reduction in perceived stress (eta2 = 0.13) were found. In addition, Tai Chi exercise statistically significantly increased self-efficacy to overcome barriers to Tai Chi (eta2 = 0.19), confidence to perform Tai Chi (eta2 = 0.27), and perceived social support (eta2 = 0.12). Tai Chi was a culturally appropriate mind-body exercise for these older adults, with statistically significant psychosocial benefits observed over 12-weeks. Further research examining Tai Chi exercise using a randomized

Tai Chi for Risk of Falls. A Meta-analysis.

PubMed

Lomas-Vega, Rafael; Obrero-Gaitán, Esteban; Molina-Ortega, Francisco J; Del-Pino-Casado, Rafael

2017-09-01

To analyze the effectiveness of tai chi for falls prevention. Systematic review and meta-analysis. Pubmed, Scopus, CINHAL, and Physiotherapy Evidence Database (PEDro) were searched to May 26, 2016. Older adult population and at-risk adults. Randomized controlled trials analyzing the effect of tai chi versus other treatments on risk of falls. The incidence rate ratio (IRR) for falls incidence and hazard ratio (HR) for time to first fall. The search strategy identified 891 potentially eligible studies, of which 10 met the inclusion criteria. There was high-quality evidence of a medium protective effect for fall incidence over the short term (IRR = 0.57; 95% CI = 0.46, 0.70) and a small protective effect over the long term (IRR = 0.87; 95% CI = 0.77, 0.98). Regarding injurious falls, we found very low-quality evidence of a medium protective effect over the short term (IRR = 0.50; 95% CI = 0.33, 0.74) and a small effect over the long term (IRR = 0.72; 95% CI = 0.54, 0.95). There was no effect on time to first fall, with moderate quality of evidence (HR = 0.98; 95% CI = 0.69, 1.37). In at-risk adults and older adults, tai chi practice may reduce the rate of falls and injury-related falls over the short term (<12 months) by approximately 43% and 50%, respectively. Tai chi practice may not influence time to first fall in these populations. Due to the low quality of evidence, more studies investigating the effects of tai chi on injurious falls and time to first fall are required. © 2017, Copyright the Authors Journal compilation © 2017, The American Geriatrics Society.

Tai Chi exercise and the improvement of health and well-being in older adults.

PubMed

Yau, Matthew Kwai-sang

2008-01-01

Activity participation has a positive impact on both quantity and quality of life (QOL). Regular participations in physical, social, and cultural activities are associated with successful aging. There is considerable evidence that Tai Chi has positive health benefits; physical, psychosocial and therapeutic. Furthermore, Tai Chi does not only consist of a physical component, but also sociocultural, meditative components that are believed to contribute to overall well-being. This chapter describes the benefits of Tai Chi exercise for the older adults, particularly in terms of the psychosocial aspect. The perceived meanings, associated values and well-being, as well as the impact on QOL, of Tai Chi practice among the older adults in Hong Kong are also discussed. Tai Chi exercise is chosen by the elderly participants for its gentle and soft movements. Besides the physical aspect, the benefits they describe include lifestyle issues, as well as psychological and social benefits. Evidence points out that the improvements in physical and mental health through the practice of Tai Chi among the older adults are related to their perceived level of QOL. Findings from numerous studies support the belief that the practice of Tai Chi has multiple benefits to practitioners that are not only physical in nature. It is recommended as a strategy to promote successful aging.

Tai Chi for Posttraumatic Stress Disorder and Chronic Musculoskeletal Pain: A Pilot Study.

PubMed

Tsai, Pao-Feng; Kitch, Stephanie; Chang, Jason Y; James, G Andrew; Dubbert, Patricia; Roca, J Vincent; Powers, Cheralyn H

2018-06-01

Explore the feasibility of a Tai Chi intervention to improve musculoskeletal pain, emotion, cognition, and physical function in individuals with posttraumatic stress disorder. Two-phase, one-arm quasi-experimental design. Phase 1: 11 participants completed one Tai Chi session, feasibility questionnaire, and were offered participation in Phase 2, a 12-week Tai Chi intervention. Ten participants participated in Phase 2. Pain intensity, interference, physical function scales, an emotional battery, and cognition tests were used for pre- and postintervention outcome measures. Paired t tests and thematic analysis were used for analysis. In Phase 1, most felt Tai Chi would benefit health (90.9%) and expressed interest in continuing Tai Chi (6.73 out of 7). Phase 2 results showed improvement in fear-affect (raw t = -2.64, p = .03; age adjusted t = -2.90, p = .02), fear-somatic arousal (raw t = -2.53, p = .035), List Sorting Working Memory (raw t = 2.62, p = .031; age adjusted t = 2.96, p = .018), 6-Minute Walk Test ( t = 3.541, p = .008), and current level of Pain Intensity ( t = -4.00, p = .004). Tai Chi is an acceptable, holistic treatment to individuals with musculoskeletal pain and posttraumatic stress disorder. It may reduce pain, improve emotion, memory, and physical function.

Characterization of the biological activity of a potent small molecule Hec1 inhibitor TAI-1

PubMed Central

2014-01-01

Background Hec1 (NDC80) is an integral part of the kinetochore and is overexpressed in a variety of human cancers, making it an attractive molecular target for the design of novel anticancer therapeutics. A highly potent first-in-class compound targeting Hec1, TAI-1, was identified and is characterized in this study to determine its potential as an anticancer agent for clinical utility. Methods The in vitro potency, cancer cell specificity, synergy activity, and markers for response of TAI-1 were evaluated with cell lines. Mechanism of action was confirmed with western blotting and immunofluorescent staining. The in vivo potency of TAI-1 was evaluated in three xenograft models in mice. Preliminary toxicity was evaluated in mice. Specificity to the target was tested with a kinase panel. Cardiac safety was evaluated with hERG assay. Clinical correlation was performed with human gene database. Results TAI-1 showed strong potency across a broad spectrum of tumor cells. TAI-1 disrupted Hec1-Nek2 protein interaction, led to Nek2 degradation, induced significant chromosomal misalignment in metaphase, and induced apoptotic cell death. TAI-1 was effective orally in in vivo animal models of triple negative breast cancer, colon cancer and liver cancer. Preliminary toxicity shows no effect on the body weights, organ weights, and blood indices at efficacious doses. TAI-1 shows high specificity to cancer cells and to target and had no effect on the cardiac channel hERG. TAI-1 is synergistic with doxorubicin, topotecan and paclitaxel in leukemia, breast and liver cancer cells. Sensitivity to TAI-1 was associated with the status of RB and P53 gene. Knockdown of RB and P53 in cancer cells increased sensitivity to TAI-1. Hec1-overexpressing molecular subtypes of human lung cancer were identified. Conclusions The excellent potency, safety and synergistic profiles of this potent first-in-class Hec1-targeted small molecule TAI-1 show its potential for clinically utility in anti

Kinematic and electromyographic analysis of the push movement in tai chi

PubMed Central

Chan, S; Luk, T; Hong, Y

2003-01-01

Background: Tai chi is a form of exercise derived from the martial art folk traditions of China. The force used in tai chi includes different principles of mechanical advantage. No studies on the kinematic features of tai chi exercise have been published. Objective: To analyse the kinematics and electromyographic characteristics of tai chi. Methods: An experienced tai chi master was asked to perform a sequence of basic movements: ward off, roll back, press, and push. The movements were videotaped and digitised using a motion analysis system. Electromyographic activities of the lumbar erector spinae, rectus femoris, medial hamstrings, and medial head of gastrocnemius were recorded by surface electrodes. The push movement data were analysed. Results: The medial hamstrings and medial head of gastrocnemius muscle groups maintained low activity, with higher electromyographic values in the lumbar erector spinae and substantially higher ones in the rectus femoris during the push movement. Both concentric and eccentric contractions occurred in muscles of the lower limbs, with eccentric contraction occurring mainly in the anti-gravity muscles such as the rectus femoris and the medial head of gastrocnemius. The forward and backward shifts in centre of gravity (CG) were mainly accomplished by increasing and decreasing respectively the joint angles of the bilateral lower limbs rather than by adopting a forward or backward postural lean. The path of the CG in the anteroposterior and mediolateral component was unique, and the sway or deviation from the path was small. The master maintained an upright posture and maintained a low CG (hips, knees, and ankles bent) while travelling slowly and steadily from one position to another. Conclusion: The eccentric muscle contraction of the lower limbs in the push movement of tai chi may help to strengthen the muscles. PMID:12893721

Effectiveness of Tai-Chi for decreasing acute pain in fibromyalgia patients.

PubMed

Segura-Jiménez, V; Romero-Zurita, A; Carbonell-Baeza, A; Aparicio, V A; Ruiz, J R; Delgado-Fernández, M

2014-05-01

Tai-Chi has shown benefits in physical and psychological outcomes in diverse populations. We aimed to determine the changes elicited by a Tai-Chi program (12 and 24 weeks) in acute pain (before vs. after session) in fibromyalgia patients. We also assessed the cumulative changes in pain brought about by a Tai-Chi program. Thirty-six patients (29 women) with fibromyalgia participated in a low-moderate intensity Tai-Chi program for 12 weeks (3 sessions/week). Twenty-eight patients (27 women) continued the program for an additional 12 weeks (i. e., 24 weeks). We assessed pain by means of a Visual Analogue Scale (VAS) before and after each single session (i. e., 72 sessions). We observed significant immediate changes (P-values from 0.037 to 0.0001) with an approximately 12% mean decrease of acute pain in the comparison of VAS-values before and after each session (72 sessions in total), with the exception of 4 sessions. We observed significant changes in cumulative pain pre-session (95% CI=-0.019; -0.014; P<0.001) and cumulative pain post-session (95% CI=-0.021; -0.015; P<0.001) along the 24-week intervention only. In conclusion, a low-moderate intensity Tai-Chi program for 12 weeks (3 times/week) decreased levels of acute pain in fibromyalgia patients. A longer period is necessary (e. g. 24 weeks) for observing cumulative changes in pain. © Georg Thieme Verlag KG Stuttgart · New York.

Comparative Effectiveness of Tai Chi Versus Physical Therapy for Knee Osteoarthritis: A Randomized Trial.

PubMed

Wang, Chenchen; Schmid, Christopher H; Iversen, Maura D; Harvey, William F; Fielding, Roger A; Driban, Jeffrey B; Price, Lori Lyn; Wong, John B; Reid, Kieran F; Rones, Ramel; McAlindon, Timothy

2016-07-19

Few remedies effectively treat long-term pain and disability from knee osteoarthritis. Studies suggest that Tai Chi alleviates symptoms, but no trials have directly compared Tai Chi with standard therapies for osteoarthritis. To compare Tai Chi with standard physical therapy for patients with knee osteoarthritis. Randomized, 52-week, single-blind comparative effectiveness trial. (ClinicalTrials.gov: NCT01258985). An urban tertiary care academic hospital. 204 participants with symptomatic knee osteoarthritis (mean age, 60 years; 70% women; 53% white). Tai Chi (2 times per week for 12 weeks) or standard physical therapy (2 times per week for 6 weeks, followed by 6 weeks of monitored home exercise). The primary outcome was Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score at 12 weeks. Secondary outcomes included physical function, depression, medication use, and quality of life. At 12 weeks, the WOMAC score was substantially reduced in both groups (Tai Chi, 167 points [95% CI, 145 to 190 points]; physical therapy, 143 points [CI, 119 to 167 points]). The between-group difference was not significant (24 points [CI, -10 to 58 points]). Both groups also showed similar clinically significant improvement in most secondary outcomes, and the benefits were maintained up to 52 weeks. Of note, the Tai Chi group had significantly greater improvements in depression and the physical component of quality of life. The benefit of Tai Chi was consistent across instructors. No serious adverse events occurred. Patients were aware of their treatment group assignment, and the generalizability of the findings to other settings remains undetermined. Tai Chi produced beneficial effects similar to those of a standard course of physical therapy in the treatment of knee osteoarthritis. National Center for Complementary and Integrative Health of the National Institutes of Health.

Foot forces induced through Tai Chi push-hand exercises.

PubMed

Wong, Shiu Hong; Ji, Tianjian; Hong, Youlian; Fok, Siu Lun; Wang, Lin

2013-08-01

The low impact forces of Tai Chi push-hand exercises may be particularly suited for older people and for those with arthritis; however, the biomechanics of push-hand exercises have not previously been reported. This paper examines the ground reaction forces (GRFs) and plantar force distributions during Tai Chi push-hand exercises in a stationary stance with and without an opponent. Ten male Tai Chi practitioners participated in the study. The GRFs of each foot were measured in three perpendicular directions using two force plates (Kistler). The plantar force distribution of each foot was measured concurrently using an insole sensor system (Novel). The results showed that the average maximum vertical GRF of each foot was not more than 88% ± 6.1% of the body weight and the sum of the vertical forces (103% ± 1.4%) generated by the two feet approximately equals the body weight at any one time. The horizontal GRFs generated by the two feet were in the opposite directions and the measured mean peak values were not more than 12% ± 2.8% and 17% ± 4.3% of the body weight in the medio-lateral and antero-posterior directions respectively. Among the nine plantar areas, the toes sustained the greatest plantar force. This study indicates that push-hand exercises generate lower vertical forces than those induced by walking, bouncing, jumping and Tai Chi gait, and that the greatest plantar force is located in the toe area, which may have an important application in balance training particularly for older adults.

"Stretch Your Body and Your Mind" (Tai Chi as an Adaptive Activity).

ERIC Educational Resources Information Center

Crider, Duane A.; Klinger, William

Tai Chi may be an ideal activity for accommodating a wide variety of individuals with varying interests and physical skills while providing substantial health benefits. Theory suggests that children, adolescents, and healthy adults, as well as senior citizens and people debilitated by illness or injury, may benefit from the practice of Tai Chi…

Effect of tai chi versus aerobic exercise for fibromyalgia: comparative effectiveness randomized controlled trial

PubMed Central

Schmid, Christopher H; Fielding, Roger A; Harvey, William F; Reid, Kieran F; Price, Lori Lyn; Driban, Jeffrey B; Kalish, Robert; Rones, Ramel; McAlindon, Timothy

2018-01-01

Abstract Objectives To determine the effectiveness of tai chi interventions compared with aerobic exercise, a current core standard treatment in patients with fibromyalgia, and to test whether the effectiveness of tai chi depends on its dosage or duration. Design Prospective, randomized, 52 week, single blind comparative effectiveness trial. Setting Urban tertiary care academic hospital in the United States between March 2012 and September 2016. Participants 226 adults with fibromyalgia (as defined by the American College of Rheumatology 1990 and 2010 criteria) were included in the intention to treat analyses: 151 were assigned to one of four tai chi groups and 75 to an aerobic exercise group. Interventions Participants were randomly assigned to either supervised aerobic exercise (24 weeks, twice weekly) or one of four classic Yang style supervised tai chi interventions (12 or 24 weeks, once or twice weekly). Participants were followed for 52 weeks. Adherence was rigorously encouraged in person and by telephone. Main outcome measures The primary outcome was change in the revised fibromyalgia impact questionnaire (FIQR) scores at 24 weeks compared with baseline. Secondary outcomes included changes of scores in patient’s global assessment, anxiety, depression, self efficacy, coping strategies, physical functional performance, functional limitation, sleep, and health related quality of life. Results FIQR scores improved in all five treatment groups, but the combined tai chi groups improved statistically significantly more than the aerobic exercise group in FIQR scores at 24 weeks (difference between groups=5.5 points, 95% confidence interval 0.6 to 10.4, P=0.03) and several secondary outcomes (patient’s global assessment=0.9 points, 0.3 to 1.4, P=0.005; anxiety=1.2 points, 0.3 to 2.1, P=0.006; self efficacy=1.0 points, 0.5 to 1.6, P=0.0004; and coping strategies, 2.6 points, 0.8 to 4.3, P=0.005). Tai chi treatment compared with aerobic exercise administered with

Effect of tai chi versus aerobic exercise for fibromyalgia: comparative effectiveness randomized controlled trial.

PubMed

Wang, Chenchen; Schmid, Christopher H; Fielding, Roger A; Harvey, William F; Reid, Kieran F; Price, Lori Lyn; Driban, Jeffrey B; Kalish, Robert; Rones, Ramel; McAlindon, Timothy

2018-03-21

To determine the effectiveness of tai chi interventions compared with aerobic exercise, a current core standard treatment in patients with fibromyalgia, and to test whether the effectiveness of tai chi depends on its dosage or duration. Prospective, randomized, 52 week, single blind comparative effectiveness trial. Urban tertiary care academic hospital in the United States between March 2012 and September 2016. 226 adults with fibromyalgia (as defined by the American College of Rheumatology 1990 and 2010 criteria) were included in the intention to treat analyses: 151 were assigned to one of four tai chi groups and 75 to an aerobic exercise group. Participants were randomly assigned to either supervised aerobic exercise (24 weeks, twice weekly) or one of four classic Yang style supervised tai chi interventions (12 or 24 weeks, once or twice weekly). Participants were followed for 52 weeks. Adherence was rigorously encouraged in person and by telephone. The primary outcome was change in the revised fibromyalgia impact questionnaire (FIQR) scores at 24 weeks compared with baseline. Secondary outcomes included changes of scores in patient's global assessment, anxiety, depression, self efficacy, coping strategies, physical functional performance, functional limitation, sleep, and health related quality of life. FIQR scores improved in all five treatment groups, but the combined tai chi groups improved statistically significantly more than the aerobic exercise group in FIQR scores at 24 weeks (difference between groups=5.5 points, 95% confidence interval 0.6 to 10.4, P=0.03) and several secondary outcomes (patient's global assessment=0.9 points, 0.3 to 1.4, P=0.005; anxiety=1.2 points, 0.3 to 2.1, P=0.006; self efficacy=1.0 points, 0.5 to 1.6, P=0.0004; and coping strategies, 2.6 points, 0.8 to 4.3, P=0.005). Tai chi treatment compared with aerobic exercise administered with the same intensity and duration (24 weeks, twice weekly) had greater benefit (between group

A review of current timed-AI (TAI) programs for beef and dairy cattle.

PubMed

Colazo, Marcos G; Mapletoft, Reuben J

2014-08-01

This is a review of the physiology and endocrinology of the estrous cycle and how ovarian physiology can be manipulated and controlled for timed artificial insemination (TAI) in beef and dairy cattle. Estrus detection is required for artificial insemination (AI), but it is done poorly in dairy cattle and it is difficult in beef cattle. Protocols that synchronize follicle growth, corpus luteum regression and ovulation, allowing for TAI, result in improved reproductive performance, because all animals are inseminated whether they show estrus or not. As result, TAI programs have become an integral part of reproductive management in many dairy herds and offer beef producers the opportunity to incorporate AI into their herds. Gonadotropin-releasing hormone-based protocols are commonly used in North America for estrus synchronization as part of a TAI program. Protocols that increase pregnancy rates in lactating dairy cows and suckling beef cows have been developed. Protocols that improve pregnancy rates in heifers, acyclic beef cows, and resynchronized lactating dairy cows are also discussed.

Spatial and temporal ecological risk assessment of unionized ammonia nitrogen in Tai Lake, China (2004-2015).

PubMed

Li, Yabing; Xu, Elvis Genbo; Liu, Wei; Chen, Yi; Liu, Hongling; Li, Di; Liu, Zhengtao; Giesy, John P; Yu, Hongxia

2017-06-01

Ammonia toxicity varies largely due to its pH- and temperature-dependent speciation (unionized ammonia nitrogen, NH 3 -N). The seasonal and long-term trend of ammonia risk in ecologically significant sections of Tai Lake, China was unknown. In this study, a two-level (deterministic and quantitative) method was developed to assess the special ecological risks posed by NH 3 -N at 37 sites during two seasons (February and September) of 2014 in Tai Lake. The long-term temporal (2004-2015) risk posed by NH 3 -N was also assessed by comparing annual quantitative risk values (probability of exceeding acute or chronic threshold values) in three key sections of Tai Lake. The results indicated the species living in the Tai Lake were at a 0.04% and 32.45% chance of risk due to acute exposure, and a 1.97% and 92.05% chance of risk due to chronic exposure in February and September of 2014, respectively. Alarmingly, the chronic ecological risks of NH 3 -N in the Lanshanzui section of the Tai Lake remained >30% from 2004 to 2011. The chronic risk of NH 3 -N in all three key sections of Tai Lake started to decrease in 2011. This was likely the consequence of the control practice of eutrophication implemented in the Tai Lake. A significant decline in diversity of the benthic invertebrate community of the Tai Lake could be associated with continuous exposure to ammonia over decades given different sensitivity of taxa to ammonia. The results laid a scientific foundation for risk assessment and management of ammonia in Tai Lake, China, and the developed two-level risk assessment approach can also be applied to other similar aquatic regions. Copyright © 2017 Elsevier Inc. All rights reserved.

Distribution and sources of particulate mercury and other trace elements in PM2.5 and PM10 atop Mount Tai, China.

PubMed

Qie, Guanghao; Wang, Yan; Wu, Chen; Mao, Huiting; Zhang, Ping; Li, Tao; Li, Yaxin; Talbot, Robert; Hou, Chenxiao; Yue, Taixing

2018-06-01

The concentrations of particulate mercury (PHg) and other trace elements in PM 2.5 and PM 10 in the atmosphere were measured at the summit of Mount Tai during the time period of 15 June - 11 August 2015. The average PHg concentrations were 83.33 ± 119.1 pg/m 3 for PM 2.5 and 174.92 ± 210.5 pg/m 3 for PM 10 . Average concentrations for other trace elements, including Al, Ca, Fe, K, Mg, Na, Pb, As, Se, Cu, Cd, Cr, V, Mo, Co, Ag, Ba, Mn, Zn and Ni ranged from 0.06 ng/m 3 (Ag) to 354.33 ng/m 3 (Ca) in PM 2.5 and 0.11 ng/m 3 (Co) to 592.66 ng/m 3 (Ca) in PM 10 . The average concentrations of PHg were higher than those at other domestic mountain sites and cities in other counties, lower than those at domestic city sites. Other trace elements showed concentrations lower than those at the domestic mountain sites. Due possibly to increased control of emissions and the proportion of new energy, the PHg and trace element concentrations decreased, but the PHg showed concentrations higher than those at the Mountain sites, this showed that the reasons was not only severely affected by anthropogenic emissions, but also associated with other sources. The concentration changed trend of the main trace elements indicated that PHg, trace elements and particle matters present positive correlation and fine particulate matter has a greater surface area which was conductive to adsorption of Hg and trace elements to particles. On June 19, June 27 and July 6, according to the peak of mercury and trace elements, we can predict the potential sources of these three days. The results of principal component analysis (PCA) suggested that, crustal dust, coal combustion, and vehicle emissions were the main emission sources of PHg and other trace elements in Mount Tai. The 24-h backward trajectories and potential source contribution function (PSCF) analysis revealed that air masses arriving at Mount Tai were mainly affected by Shandong province. Mount Tai was subjected to five

Tai Chi for Chronic Pain Conditions: A Systematic Review and Meta-analysis of Randomized Controlled Trials

PubMed Central

Kong, Ling Jun; Lauche, Romy; Klose, Petra; Bu, Jiang Hui; Yang, Xiao Cun; Guo, Chao Qing; Dobos, Gustav; Cheng, Ying Wu

2016-01-01

Several studies reported that Tai Chi showed potential effects for chronic pain, but its role remains controversial. This review assessed the evidence regarding the effects of Tai Chi for chronic pain conditions. 18 randomized controlled trials were included in our review. The aggregated results have indicated that Tai Chi showed positive evidence on immediate relief of chronic pain from osteoarthritis (standardized mean difference [SMD], −0.54; 95% confidence intervals [CI], −0.77 to −0.30; P < 0.05). The valid duration of Tai Chi practice for osteoarthritis may be more than 5 weeks. And there were some beneficial evidences regarding the effects of Tai Chi on immediate relief of chronic pain from low back pain (SMD, −0.81; 95% CI, −1.11 to −0.52; P < 0.05) and osteoporosis (SMD, −0.83; 95% CI, −1.37 to −0.28; P = 0.003). Therefore, clinicians may consider Tai Chi as a viable complementary and alternative medicine for chronic pain conditions. PMID:27125299

Study on community Tai Chi Chuan participants' leisure benefits and well-being: Using Taoyuan City as an example.

PubMed

Lee, Cheng-Jong; Tseng, Chun-Chi; Liu, Mei-Yu

2015-01-01

The aim of this study was to discuss the Research of Community Tai Chi Chuan Participants' Leisure Benefits and Well-being. A questionnaire survey was conducted on the community Tai Chi Chuan participants in Taoyuan city. A total of 500 valid questionnaires were retrieved, and the data were analyzed with SPSS 12.0 and AMOS 7.0 structural equation model analysis (SEM). The findings were as followed: 1) The background variables of the community Tai Chi Chuan participants in Taoyuan City: Gender had no difference in the factor of ``psychological benefit'' of leisure benefits. Occupation, age, education, the number of times a week to participate community Tai Chi Chuan and participation in seniority reached significant difference in leisure benefits. 2) The background variables of the community Tai Chi Chuan participants in Taoyuan City: gender, occupation, age, education, the number of times a week to participate community Tai Chi Chuan, participation in seniority reached significant difference in well-being. 3) The study showed community Tai Chi Chuan participants' leisure benefits had a significant positive correlation in well-being. Based on the findings, suggestions were proposed to related Taiwan Tai Chi Chuan promotion for reference.

Ethnobotanical study of medicinal plants used by Tai Yai in Northern Thailand.

PubMed

Khuankaew, Sunee; Srithi, Kamonnate; Tiansawat, Pimonrat; Jampeetong, Arunothai; Inta, Angkhana; Wangpakapattanawong, Prasit

2014-02-03

We studied traditional knowledge of medicinal plants used by Tai Yai people in Northern Thailand. We documented traditional medical practices and determined importance among the Tai Yai. This paper reports on knowledge in usage of medicinal plants of the Tai Yai people in Northern Thailand. Interviews were conducted in 4 Tai Yai villages in Mae Hong Son and Chiang Mai provinces whose inhabitants immigrated from Myanmar at different times. Discussions and interviews were held with 126 key-informants (56 males and 70 females) ranging in age from 16 to 80 years in three age groups (age 16-40, 41-60, and 61-80). We calculated the informant consensus factor (ICF) for use category, use value index (UV) for use report of plant. We tested differences between the knowledge of different age groups and locations using principal component analysis (PCA). These Tai Yai people used of 141 medicinal plants belonging to 59 families. Of the medicinal plant species, the highest percentage was in the family Euphorbiaceae: Croton acutifolius and Croton roxburghii. The highest number of Informant consensus factor was for metabolic system disorders. Overall, Tai Yai people use medicinal plants to cure many sicknesses such as hypertension, lumbago, wounds, puerperium, kidney disorders, kidney stones, coughs, fevers, hemorrhoids, flatulence and malaria. There were no significant differences in knowledge of plants usage among villages of different ages. In addition, the knowledge of the plants was not significantly different between men and women. However, we found that the younger had less experience with and knowledge of medicinal plants than older people. The result indicates loss of accumulated knowledge of medicinal plants and traditional use. Although, the medicinal plant knowledge was passed from one generation to the next by word of mouth, the detailed documentation of medicinal plants and their use may effectively prevent the knowledge-loss through time. © 2013 Elsevier Ireland

Impact of new clock technologies on the stability and accuracy of the International Atomic Time TAI.

NASA Astrophysics Data System (ADS)

Thomas, C.

1997-05-01

The BIPM Time Section is in charge of the generation of the reference time scales TAI and UTC. Both time scales are obtained in deferred-time by combining the data front a number of atomic clocks spread worldwide. The accuracy of TAI is estimated by the departure between the duration of the TAI scale interval and the SI second as produced on the rotating geoid by primary frequency standards. It is now possible to estimate TAI accuracy through the combination of results obtained from six different primary standards: LPTF-FO1, PTB CS1, PTB CS2, PTB CS3, NIST-7, and SU MCsR 102, all corrected for the black-body radiation shift. This led to a mean departure of the TAI scale interval of +2.0×10-14s over 1995, known with a relative uncertainty of 0.5×10-14(1σ).

Validation of the 'Test of the Adherence to Inhalers' (TAI) for Asthma and COPD Patients.

PubMed

Plaza, Vicente; Fernández-Rodríguez, Concepción; Melero, Carlos; Cosío, Borja G; Entrenas, Luís Manuel; de Llano, Luis Pérez; Gutiérrez-Pereyra, Fernando; Tarragona, Eduard; Palomino, Rosa; López-Viña, Antolín

2016-04-01

To validate the 'Test of Adherence to Inhalers' (TAI), a 12-item questionnaire designed to assess the adherence to inhalers in patients with COPD or asthma. A total of 1009 patients with asthma or COPD participated in a cross-sectional multicenter study. Patients with electronic adherence ≥80% were defined as adherents. Construct validity, internal validity, and criterion validity were evaluated. Self-reported adherence was compared with the Morisky-Green questionnaire. Factor analysis study demonstrated two factors, factor 1 was coincident with TAI patient domain (items 1 to 10) and factor 2 with TAI health-care professional domain (items 11 and 12). The Cronbach's alpha was 0.860 and the test-retest reliability 0.883. TAI scores correlated with electronic adherence (ρ=0.293, p=0.01). According to the best cut-off for 10 items (score 50, area under the ROC curve 0.7), 569 (62.5%) patients were classified as non-adherents. The non-adherence behavior pattern was: erratic 527 (57.9%), deliberate 375 (41.2%), and unwitting 242 (26.6%) patients. As compared to Morisky-Green test, TAI showed better psychometric properties. The TAI is a reliable and homogeneous questionnaire to identify easily non-adherence and to classify from a clinical perspective the barriers related to the use of inhalers in asthma and COPD.

A review of current timed-AI (TAI) programs for beef and dairy cattle

PubMed Central

Colazo, Marcos G.; Mapletoft, Reuben J.

2014-01-01

This is a review of the physiology and endocrinology of the estrous cycle and how ovarian physiology can be manipulated and controlled for timed artificial insemination (TAI) in beef and dairy cattle. Estrus detection is required for artificial insemination (AI), but it is done poorly in dairy cattle and it is difficult in beef cattle. Protocols that synchronize follicle growth, corpus luteum regression and ovulation, allowing for TAI, result in improved reproductive performance, because all animals are inseminated whether they show estrus or not. As result, TAI programs have become an integral part of reproductive management in many dairy herds and offer beef producers the opportunity to incorporate AI into their herds. Gonadotropin-releasing hormone-based protocols are commonly used in North America for estrus synchronization as part of a TAI program. Protocols that increase pregnancy rates in lactating dairy cows and suckling beef cows have been developed. Protocols that improve pregnancy rates in heifers, acyclic beef cows, and resynchronized lactating dairy cows are also discussed. PMID:25082993

Epidemic characteristics and spatio-temporal patterns of scrub typhus during 2006-2013 in Tai'an, Northern China.

PubMed

Zheng, L; Yang, H-L; Bi, Z-W; Kou, Z-Q; Zhang, L-Y; Zhang, A-H; Yang, L; Zhao, Z-T

2015-08-01

Tai'an, a famous cultural tourist district, is a new endemic foci of scrub typhus in northern China. Frequent reports of travel-acquired cases and absence of effective vaccine indicated a significant health problem of scrub typhus in Tai'an. Thus, descriptive epidemiological methods and spatial-temporal scan statistics were used to describe the epidemic characteristics and detect the significant clusters of the high incidence of scrub typhus at the town level in Tai'an. Results of descriptive epidemiological analysis showed a total of 490 cases were reported in Tai'an with the annual average incidence ranging from 0·48 to 2·27/100 000 during 2006-2013. Females, the elderly and farmers are the high-risk groups. Monthly changes of scrub typhus cases indicated an obvious epidemic period in autumn. Spatial-temporal distribution analysis, showed significant clusters of high incidence mainly located in eastern and northern Tai'an. Our study suggests that more effective, targeted measures for local residents should be implemented in the eastern and northern areas of Tai'an in autumn. Meanwhile, it may prove beneficial for health policy makers to advise travellers to take preventive measures in order to minimize the risk of infection of scrub typhus in Tai'an.

An evidence map of the effect of Tai Chi on health outcomes.

PubMed

Solloway, Michele R; Taylor, Stephanie L; Shekelle, Paul G; Miake-Lye, Isomi M; Beroes, Jessica M; Shanman, Roberta M; Hempel, Susanne

2016-07-27

This evidence map describes the volume and focus of Tai Chi research reporting health outcomes. Originally developed as a martial art, Tai Chi is typically taught as a series of slow, low-impact movements that integrate the breath, mind, and physical activity to achieve greater awareness and a sense of well-being. The evidence map is based on a systematic review of systematic reviews. We searched 11 electronic databases from inception to February 2014, screened reviews of reviews, and consulted with topic experts. We used a bubble plot to graphically display clinical topics, literature size, number of reviews, and a broad estimate of effectiveness. The map is based on 107 systematic reviews. Two thirds of the reviews were published in the last five years. The topics with the largest number of published randomized controlled trials (RCTs) were general health benefits (51 RCTs), psychological well-being (37 RCTs), interventions for older adults (31 RCTs), balance (27 RCTs), hypertension (18 RCTs), fall prevention (15 RCTs), and cognitive performance (11 RCTs). The map identified a number of areas with evidence of a potentially positive treatment effect on patient outcomes, including Tai Chi for hypertension, fall prevention outside of institutions, cognitive performance, osteoarthritis, depression, chronic obstructive pulmonary disease, pain, balance confidence, and muscle strength. However, identified reviews cautioned that firm conclusions cannot be drawn due to methodological limitations in the original studies and/or an insufficient number of existing research studies. Tai Chi has been applied in diverse clinical areas, and for a number of these, systematic reviews have indicated promising results. The evidence map provides a visual overview of Tai Chi research volume and content. PROSPERO CRD42014009907.

On Optimizing the Configuration of Time-Transfer Links Used to Generate TAI

DTIC Science & Technology

2007-01-01

TAI be generated through combinations of Two Way Satellite Time and Frequency Transfer ( TWSTFT ) links and GPS links. It is assumed that Study Group I...the lack of low-noise connectivity between the Asian and American-European TWSTFT links may require two pivot sites instead of one. We recommend...band Two Way Satellite Time and Frequency Transfer ( TWSTFT ), and X-band TWSTFT [1]. In order to improve TAI-generation, the BIPM Time Section asked

Does Tai Chi relieve fatigue? A systematic review and meta-analysis of randomized controlled trials

PubMed Central

Xiang, Yu; Lu, Liming; Chen, Xiankun

2017-01-01

Background Fatigue is not only a familiar symptom in our daily lives, but also a common ailment that affects all of our bodily systems. Several randomized controlled trials (RCTs) have proven Tai Chi to be beneficial for patients suffering from fatigue, however conclusive evidence is still lacking. A systematic review and meta-analysis was performed on all RCTs reporting the effects of Tai Chi for fatigue. Methods In the end of April 2016, seven electronic databases were searched for RCTs involving Tai Chi for fatigue. The search terms mainly included Tai Chi, Tai-ji, Taiji, fatigue, tiredness, weary, weak, and the search was conducted without language restrictions. Methodological quality was assessed using the Cochrane Risk of Bias tool. RevMan 5.3 software was used for meta-analysis. Publication bias was estimated with a funnel plot and Egger’s test. We also assessed the quality of evidence with the GRADE system. Results Ten trials (n = 689) were included, and there was a high risk of bias in the blinding. Two trials were determined to have had low methodological quality. Tai Chi was found to have improved fatigue more than conventional therapy (standardized mean difference (SMD): -0.45, 95% confidence interval (CI): -0.70, -0.20) overall, and have positive effects in cancer-related fatigue (SMD:-0.38, 95% CI: -0.65, -0.11). Tai Chi was also more effective on vitality (SMD: 0.63, 95% CI: 0.20, 1.07), sleep (SMD: -0.32, 95% CI: -0.61, -0.04) and depression (SMD: -0.58, 95% CI: -1.04, -0.11). However, no significant difference was found in multiple sclerosis-related fatigue (SMD: -0.77, 95% CI: -1.76, 0.22) and age-related fatigue (SMD: -0.77, 95% CI: -1.78, 0.24). No adverse events were reported among the included studies. The quality of evidence was moderate in the GRADE system. Conclusions The results suggest that Tai Chi could be an effective alternative and /or complementary approach to existing therapies for people with fatigue. However, the quality of the

Effects of Tai Chi intervention on dual-task ability in older adults: a pilot study.

PubMed

Hall, Courtney D; Miszko, Tanya; Wolf, Steven L

2009-03-01

To determine if a 12-week program of Tai Chi that has been shown to reduce falls incidence in older adults would improve the ability to allocate attention to balance under dual-task conditions. Pre-/posttest experimental research design. Movement studies research laboratory. Community dwelling older adults (N=15; range, 62-85y) participated in either Tai Chi training or health education classes (controls) for 12 weeks. Participants in the Tai Chi group attended a twice-weekly, 1.5-hour class taught by an experienced instructor. The control group attended a biweekly, 1-hour class for lectures on health-related topics. Two cognitive tasks (responding to auditory or visual stimulus as quickly as possible) were performed concurrently while maintaining static balance during the Sensory Organization Test (SOT) and while avoiding obstacles while walking. The percent change in performance relative to the single-task condition was calculated and defined as the dual-task cost. The dual-task cost was calculated for both the postural and cognitive measures. There was no improvement in the performance of postural stability or cognitive task under dual-task conditions for the SOT for Tai Chi versus controls. There was no improvement in avoiding obstacles under dual-task conditions for Tai Chi versus controls. Contrary to our hypothesis, the findings of this study did not support a benefit of Tai Chi on the ability to allocate attention to balance under dual-task conditions.

Effects of Tai Chi exercise on physical and psychological health of older people.

PubMed

Blake, Holly; Hawley, Helen

2012-02-01

Tai Chi is a traditional Chinese form of conditioning exercise derived from martial arts and rooted in eastern philosophy and Chinese Medicine. Based on the inter-relatedness of mind, body and spirit this form of exercise focuses on producing an inner calmness which is thought to have both physical and psychological therapeutic value. This article provides a brief overview of selected current evidence examining the relationship between Tai Chi and physical, neurocognitive and psychosocial outcomes in older people. This is an emerging and growing area of research and improvements have often been reported in health functioning, physical and emotional health, reducing falls, fear of falling and risk of falls, and possibly enhancing cardiovascular functioning in older adults although the effects on bone density, cognitive and immunological functioning are less clear. Results overall are inconsistent and health improvements have not been evident in all studies. Tai Chi is becoming increasingly popular in practice, and more recent evidence is emerging which is based on experimental and longitudinal designs, although many of the proposed benefits of Tai Chi are yet to be validated in large, randomised controlled trials.

Seated Tai Chi to alleviate pain and improve quality of life in individuals with spinal cord disorder

PubMed Central

Karasik, Darlene; Carufel, Paul; Kao, Ming-Chih; Zheng, Patricia

2016-01-01

Context Previous research studies have confirmed therapeutic physical and psychological benefits of Tai Chi for both the able-bodied and disabled populations. However, given the limited availability of seated Tai Chi, there have not been any studies to date that have examined the effectiveness of seated Tai Chi in individuals with spinal cord disorder (SCD). We designed a customized seated Tai Chi program to meet the need for improved exercise options for individuals with SCD. Findings Twenty-six participants were enrolled in a 12-week seated Tai Chi course consisting of weekly sessions. After each Tai Chi session, patients reported improved visual analog scale (VAS) monitoring pain (P) (3.18 v 2.93; P 1.63E-03), emotional sense of well-being (EWB) (2.61 vs 2.04; P 2.86E-07), mental distraction (MD) (3.13 v 2.29; P 9.36E-08), physical sense of well-being (PWB) (2.84 v 2.25; p 7.38E-08), and sense of spiritual connection (SC) (3.28 v 2.50; P 6.46E-08). In our limited follow-up of 9 participants who completed half of the sessions and the long term surveys after the 12-week course, there were no detectable differences in weekly P, EWB, MD, PWB, and SC before each session. Conclusion and Clinical Relevance Individuals with SCD demonstrated benefits in pain, emotional sense of well-being, mental distraction, physical sense of well-being, and sense of spiritual connection immediately after seated Tai Chi exercise sessions in our pilot study. More research in a larger population would be needed to study the long-term impact of seated Tai Chi. PMID:26914968

Tai Chi Chuan and Baduanjin Increase Grey Matter Volume in Older Adults: A Brain Imaging Study.

PubMed

Tao, Jing; Liu, Jiao; Liu, Weilin; Huang, Jia; Xue, Xiehua; Chen, Xiangli; Wu, Jinsong; Zheng, Guohua; Chen, Bai; Li, Ming; Sun, Sharon; Jorgenson, Kristen; Lang, Courtney; Hu, Kun; Chen, Shanjia; Chen, Lidian; Kong, Jian

2017-01-01

The aim of this study is to investigate and compare how 12-weeks of Tai Chi Chuan and Baduanjin exercise can modulate brain structure and memory function in older adults. Magnetic resonance imaging and memory function measurements (Wechsler Memory Scale-Chinese revised, WMS-CR) were applied at both the beginning and end of the study. Results showed that both Tai Chi Chuan and Baduanjin could significantly increase grey matter volume (GMV) in the insula, medial temporal lobe, and putamen after 12-weeks of exercise. No significant differences were observed in GMV between the Tai Chi Chuan and Baduanjin groups. We also found that compared to healthy controls, Tai Chi Chuan and Baduanjin significantly improved visual reproduction subscores on the WMS-CR. Baduanjin also improved mental control, recognition, touch, and comprehension memory subscores of the WMS-CR compared to the control group. Memory quotient and visual reproduction subscores were both associated with GMV increases in the putamen and hippocampus. Our results demonstrate the potential of Tai Chi Chuan and Baduanjin exercise for the prevention of memory deficits in older adults.

Tai chi exercise in patients with chronic heart failure: a randomized clinical trial.

PubMed

Yeh, Gloria Y; McCarthy, Ellen P; Wayne, Peter M; Stevenson, Lynne W; Wood, Malissa J; Forman, Daniel; Davis, Roger B; Phillips, Russell S

2011-04-25

Preliminary evidence suggests that meditative exercise may have benefits for patients with chronic systolic heart failure (HF); this has not been rigorously tested in a large clinical sample. We sought to investigate whether tai chi, as an adjunct to standard care, improves functional capacity and quality of life in patients with HF. A single-blind, multisite, parallel-group, randomized controlled trial evaluated 100 outpatients with systolic HF (New York Heart Association class I-III, left ventricular ejection fraction ≤40%) who were recruited between May 1, 2005, and September 30, 2008. A group-based 12-week tai chi exercise program (n = 50) or time-matched education (n = 50, control group) was conducted. Outcome measures included exercise capacity (6- minute walk test and peak oxygen uptake) and disease-specific quality of life (Minnesota Living With Heart Failure Questionnaire). Mean (SD) age of patients was 67 (11) years; baseline values were left ventricular ejection fraction, 29% (8%) and peak oxygen uptake, 13.5 mL/kg/min; the median New York Heart Association class of HF was class II. At completion of the study, there were no significant differences in change in 6-minute walk distance and peak oxygen uptake (median change [first quartile, third quartile], 35 [-2, 51] vs 2 [-7, 54] meters, P = .95; and 1.1 [-1.1, 1.5] vs -0.5 [-1.2, 1.8] mL/kg/min, P = .81) when comparing tai chi and control groups; however, patients in the tai chi group had greater improvements in quality of life (Minnesota Living With Heart Failure Questionnaire, -19 [-23, -3] vs 1 [-16, 3], P = .02). Improvements with tai chi were also seen in exercise self-efficacy (Cardiac Exercise Self-efficacy Instrument, 0.1 [0.1, 0.6] vs -0.3 [-0.5, 0.2], P < .001) and mood (Profile of Mood States total mood disturbance, -6 [-17, 1] vs -1 [-13, 10], P = .01). Tai chi exercise may improve quality of life, mood, and exercise self-efficacy in patients with HF. Trial Registration clinicaltrials

Changes of heart rate variability and prefrontal oxygenation during Tai Chi practice versus arm ergometer cycling.

PubMed

Lu, Xi; Hui-Chan, Christina Wan-Ying; Tsang, William Wai-Nam

2016-11-01

[Purpose] Exercise has been shown to improve cardiovascular fitness and cognitive function. Whether the inclusion of mind over exercise would increase parasympathetic control of the heart and brain activities more than general exercise at a similar intensity is not known. The aim of this study was to compare the effects of Tai Chi (mind-body exercise) versus arm ergometer cycling (body-focused exercise) on the heart rate variability and prefrontal oxygenation level. [Subjects and Methods] A Tai Chi master was invited to perform Tai Chi and arm ergometer cycling with similar exercise intensity on two separate days. Heart rate variability and prefrontal oxyhemoglobin levels were measured continuously by a RR recorder and near-infrared spectroscopy, respectively. [Results] During Tai Chi exercise, spectral analysis of heart rate variability demonstrated a higher high-frequency power as well as a lower low-frequency/high-frequency ratio than during ergometer cycling, suggesting increased parasympathetic and decreased sympathetic control of the heart. Also, prefrontal oxyhemoglobin and total hemoglobin levels were higher than those during arm ergometer exercise. [Conclusion] These findings suggest that increased parasympathetic control of the heart and prefrontal activities may be associated with Tai Chi practice. Having a "mind" component in Tai Chi could be more beneficial for older adults' cardiac health and cognitive function than body-focused ergometer cycling.

Analysis of static and dynamic balance in healthy elderly practitioners of Tai Chi Chuan versus ballroom dancing

PubMed Central

Rahal, Miguel Antônio; Alonso, Angélica Castilho; Andrusaitis, Felix Ricardo; Rodrigues, Thuam Silva; Speciali, Danielli Souza; Greve, Júlia Maria D′Andréa; Leme, Luiz Eugênio Garcez

2015-01-01

OBJECTIVE: To determine whether Tai Chi Chuan or ballroom dancing promotes better performance with respect to postural balance, gait, and postural transfer among elderly people. METHODS: We evaluated 76 elderly individuals who were divided into two groups: the Tai Chi Chuan Group and the Dance Group. The subjects were tested using the NeuroCom Balance Master® force platform system with the following protocols: static balance tests (the Modified Clinical Tests of Sensory Interaction on Balance and Unilateral Stance) and dynamic balance tests (the Walk Across Test and Sit-to-stand Transfer Test). RESULTS: In the Modified Clinical Test of Sensory Interaction on Balance, the Tai Chi Chuan Group presented a lower sway velocity on a firm surface with open and closed eyes, as well as on a foam surface with closed eyes. In the Modified Clinical Test of Sensory Interaction on Unilateral Stance, the Tai Chi Chuan Group presented a lower sway velocity with open eyes, whereas the Dance Group presented a lower sway velocity with closed eyes. In the Walk Across Test, the Tai Chi Chuan Group presented faster walking speeds than those of the Dance Group. In the Sit-to-stand Transfer Test, the Tai Chi Chuan Group presented shorter transfer times from the sitting to the standing position, with less sway in the final standing position. CONCLUSION: The elderly individuals who practiced Tai Chi Chuan had better bilateral balance with eyes open on both types of surfaces compared with the Dance Group. The Dance Group had better unilateral postural balance with eyes closed. The Tai Chi Chuan Group had faster walking speeds, shorter transfer times, and better postural balance in the final standing position during the Sit-to-stand Test. PMID:26017644

Analysis of static and dynamic balance in healthy elderly practitioners of Tai Chi Chuan versus ballroom dancing.

PubMed

Rahal, Miguel Antônio; Alonso, Angélica Castilho; Andrusaitis, Felix Ricardo; Rodrigues, Thuam Silva; Speciali, Danielli Souza; Greve, Júlia Maria D Andréa; Leme, Luiz Eugênio Garcez

2015-03-01

To determine whether Tai Chi Chuan or ballroom dancing promotes better performance with respect to postural balance, gait, and postural transfer among elderly people. We evaluated 76 elderly individuals who were divided into two groups: the Tai Chi Chuan Group and the Dance Group. The subjects were tested using the NeuroCom Balance Master¯ force platform system with the following protocols: static balance tests (the Modified Clinical Tests of Sensory Interaction on Balance and Unilateral Stance) and dynamic balance tests (the Walk Across Test and Sit-to-stand Transfer Test). In the Modified Clinical Test of Sensory Interaction on Balance, the Tai Chi Chuan Group presented a lower sway velocity on a firm surface with open and closed eyes, as well as on a foam surface with closed eyes. In the Modified Clinical Test of Sensory Interaction on Unilateral Stance, the Tai Chi Chuan Group presented a lower sway velocity with open eyes, whereas the Dance Group presented a lower sway velocity with closed eyes. In the Walk Across Test, the Tai Chi Chuan Group presented faster walking speeds than those of the Dance Group. In the Sit-to-stand Transfer Test, the Tai Chi Chuan Group presented shorter transfer times from the sitting to the standing position, with less sway in the final standing position. The elderly individuals who practiced Tai Chi Chuan had better bilateral balance with eyes open on both types of surfaces compared with the Dance Group. The Dance Group had better unilateral postural balance with eyes closed. The Tai Chi Chuan Group had faster walking speeds, shorter transfer times, and better postural balance in the final standing position during the Sit-to-stand Test.

Tai Chi for osteopenic women: design and rationale of a pragmatic randomized controlled trial

PubMed Central

2010-01-01

Background Post-menopausal osteopenic women are at increased risk for skeletal fractures. Current osteopenia treatment guidelines include exercise, however, optimal exercise regimens for attenuating bone mineral density (BMD) loss, or for addressing other fracture-related risk factors (e.g. poor balance, decreased muscle strength) are not well-defined. Tai Chi is an increasingly popular weight bearing mind-body exercise that has been reported to positively impact BMD dynamics and improve postural control, however, current evidence is inconclusive. This study will determine the effectiveness of Tai Chi in reducing rates of bone turnover in post-menopausal osteopenic women, compared with standard care, and will preliminarily explore biomechanical processes that might inform how Tai Chi impacts BMD and associated fracture risks. Methods/Design A total of 86 post-menopausal women, aged 45-70y, T-score of the hip and/or spine -1.0 and -2.5, have been recruited from primary care clinics of a large healthcare system based in Boston. They have been randomized to a group-based 9-month Tai Chi program plus standard care or to standard care only. A unique aspect of this trial is its pragmatic design, which allows participants randomized to Tai Chi to choose from a pre-screened list of community-based Tai Chi programs. Interviewers masked to participants' treatment group assess outcomes at baseline and 3 and 9 months after randomization. Primary outcomes are serum markers of bone resorption (C-terminal cross linking telopeptide of type I collagen), bone formation (osteocalcin), and BMD of the lumbar spine and proximal femur (dual-energy X-ray absorptiometry). Secondary outcomes include health-related quality-of-life, exercise behavior, and psychological well-being. In addition, kinetic and kinematic characterization of gait, standing, and rising from a chair are assessed in subset of participants (n = 16) to explore the feasibility of modeling skeletal mechanical loads and

The effect of Tai Chi exercises on postural stability and control in older patients with knee osteoarthritis.

PubMed

Ghandali, Elham; Moghadam, Saeed Talebian; Hadian, Mohammad Reza; Olyaei, Gholamreza; Jalaie, Shohreh; Sajjadi, Elaheh

2017-07-01

A few studies have examined the effect of Tai Chi on balance in elder patients with knee osteoarthritis (OA). The aim of this study was to determine the balance measures in elder patients with knee OA after Tai Chi exercises. For this purpose 14 females and 6 males with knee OA were chosen. Area and mean velocity of the center of pressure movements (CoP) were measured by force plate in standing positions (on foam and rigid surfaces). The measurements of area and mean velocity of CoP were performed before and after 60 min of Tai Chi sessions (twice a week for 8 weeks). The results showed that the area of CoP in standing position on rigid surface was significantly decreased (P < 0.01) after Tai Chi exercises. Furthermore, the mean velocity of CoP was significantly decreased after Tai Chi exercises on both rigid and foam surfaces (P < 0.001). Our study also indicated that changes in surfaces (rigid and foam) would cause significant differences regarding the area of CoP in standing positions. However, similar findings were not found regarding the mean velocity of CoP. Considering the effects of Tai Chi on mean velocity of CoP, it might be concluded that motor control and postural stability improvements have occurred. Therefore, based on these results, Tai Chi exercises could be recommended for elder patients with knee OA as part of their rehabilitation and physical therapy protocols. Copyright © 2016. Published by Elsevier Ltd.

Tai Chi Chuan and Baduanjin increase grey matter volume in older adults: a brain imaging study

PubMed Central

Tao, Jing; Liu, Jiao; Liu, Weilin; Huang, Jia; Xue, Xiehua; Chen, Xiangli; Wu, Jinsong; Zheng, Guohua; Chen, Bai; Li, Ming; Sun, Sharon; Jorgenson, Kristen; Lang, Courtney; Hu, Kun; Chen, Shanjia; Chen, Lidian; Kong, Jian

2017-01-01

The aim of this study is to investigate and compare how 12-weeks of Tai Chi Chuan and Baduanjin exercise can modulate brain structure and memory function in older adults. Magnetic Resonance Imaging(MRI) and memory function measurements (Wechsler Memory Scale-Chinese revised, WMS-CR)were applied at both the beginning and end of the study. Results showed that both Tai Chi Chuan and Baduanjin could significantly increase grey matter volume (GMV) in the insula, medial temporal lobe (MTL), and putamen after 12-weeks of exercise. No significant differences were observed in grey matter volume (GMV) between the Tai Chi Chuan and Baduanjin groups. We also found that compared to healthy controls, Tai Chi Chuan and Baduanjin significantly improved visual reproduction subscores on the WMS-CR. Baduanjin also improved mental control, recognition, touch and comprehension memory subscores of the WMS-CR compared to the control group. Memory quotient (MQ)and visual reproduction subscores were both associated with GMV increases in the putamen and hippocampus. Our results demonstrate the potential of Tai Chi Chuan and Baduanjin exercise for the prevention of memory deficits in older adults. PMID:28869478

The Effects of Tai Chi Intervention on Healthy Elderly by Means of Neuroimaging and EEG: A Systematic Review.

PubMed

Pan, Zhujun; Su, Xiwen; Fang, Qun; Hou, Lijuan; Lee, Younghan; Chen, Chih C; Lamberth, John; Kim, Mi-Lyang

2018-01-01

Aging is a process associated with a decline in cognitive and motor functions, which can be attributed to neurological changes in the brain. Tai Chi, a multimodal mind-body exercise, can be practiced by people across all ages. Previous research identified effects of Tai Chi practice on delaying cognitive and motor degeneration. Benefits in behavioral performance included improved fine and gross motor skills, postural control, muscle strength, and so forth. Neural plasticity remained in the aging brain implies that Tai Chi-associated benefits may not be limited to the behavioral level. Instead, neurological changes in the human brain play a significant role in corresponding to the behavioral improvement. However, previous studies mainly focused on the effects of behavioral performance, leaving neurological changes largely unknown. This systematic review summarized extant studies that used brain imaging techniques and EEG to examine the effects of Tai Chi on older adults. Eleven articles were eligible for the final review. Three neuroimaging techniques including fMRI ( N = 6), EEG ( N = 4), and MRI ( N = 1), were employed for different study interests. Significant changes were reported on subjects' cortical thickness, functional connectivity and homogeneity of the brain, and executive network neural function after Tai Chi intervention. The findings suggested that Tai Chi intervention give rise to beneficial neurological changes in the human brain. Future research should develop valid and convincing study design by applying neuroimaging techniques to detect effects of Tai Chi intervention on the central nervous system of older adults. By integrating neuroimaging techniques into randomized controlled trials involved with Tai Chi intervention, researchers can extend the current research focus from behavioral domain to neurological level.

Effects of regular Tai Chi practice and jogging on neuromuscular reaction during lateral postural control in older people.

PubMed

Wang, Shao-Jun; Xu, Dong-Qing; Li, Jing-Xian

2017-01-01

This study examined the effects of regular Tai Chi practice and jogging on the neuromuscular activity of the trunk, hip, and ankle joint muscles of older people during lateral postural perturbation. A total of 42 older people participated in the study and formed the Tai Chi, jogging, and sedentary control groups. Electromyography signals were collected from the peroneus longus, anterior tibialis, gluteus medius, and erector spinae during unpredictable mediolateral perturbation. The Tai Chi group exhibited significantly faster latencies of the tibialis anterior and erector spinae than the control group. The jogging group showed a significantly shorter neuromuscular reaction time of the erector spinae than the control group. No significant difference was observed between the Tai Chi and jogging groups. Long-term regular Tai Chi practice enhanced the neuromuscular reaction of the erector spinae and tibialis anterior to lateral perturbation and will help timely posture correction when lateral postural distributions occur.

Tai-Chi for Residential Patients with Schizophrenia on Movement Coordination, Negative Symptoms, and Functioning: A Pilot Randomized Controlled Trial

PubMed Central

Ho, Rainbow T. H.; Au Yeung, Friendly S. W.; Lo, Phyllis H. Y.; Law, Kit Ying; Wong, Kelvin O. K.; Cheung, Irene K. M.; Ng, Siu Man

2012-01-01

Objective. Patients with schizophrenia residing at institutions often suffer from negative symptoms, motor, and functional impairments more severe than their noninstitutionalized counterparts. Tai-chi emphasizes body relaxation, alertness, and movement coordination with benefits to balance, focus, and stress relief. This pilot study explored the efficacy of Tai-chi on movement coordination, negative symptoms, and functioning disabilities towards schizophrenia. Methods. A randomized waitlist control design was adopted, where participants were randomized to receive either the 6-week Tai-chi program and standard residential care or only the latter. 30 Chinese patients with schizophrenia were recruited from a rehabilitation residency. All were assessed on movement coordination, negative symptoms, and functional disabilities at baseline, following intervention and 6 weeks after intervention. Results. Tai-chi buffered from deteriorations in movement coordination and interpersonal functioning, the latter with sustained effectiveness 6 weeks after the class was ended. Controls showed marked deteriorations in those areas. The Tai-chi group also experienced fewer disruptions to life activities at the 6-week maintenance. There was no significant improvement in negative symptoms after Tai-chi. Conclusions. This study demonstrated encouraging benefits of Tai-chi in preventing deteriorations in movement coordination and interpersonal functioning for residential patients with schizophrenia. The ease of implementation facilitates promotion at institutional psychiatric services. PMID:23304224

Tai-chi for residential patients with schizophrenia on movement coordination, negative symptoms, and functioning: a pilot randomized controlled trial.

PubMed

Ho, Rainbow T H; Au Yeung, Friendly S W; Lo, Phyllis H Y; Law, Kit Ying; Wong, Kelvin O K; Cheung, Irene K M; Ng, Siu Man

2012-01-01

Objective. Patients with schizophrenia residing at institutions often suffer from negative symptoms, motor, and functional impairments more severe than their noninstitutionalized counterparts. Tai-chi emphasizes body relaxation, alertness, and movement coordination with benefits to balance, focus, and stress relief. This pilot study explored the efficacy of Tai-chi on movement coordination, negative symptoms, and functioning disabilities towards schizophrenia. Methods. A randomized waitlist control design was adopted, where participants were randomized to receive either the 6-week Tai-chi program and standard residential care or only the latter. 30 Chinese patients with schizophrenia were recruited from a rehabilitation residency. All were assessed on movement coordination, negative symptoms, and functional disabilities at baseline, following intervention and 6 weeks after intervention. Results. Tai-chi buffered from deteriorations in movement coordination and interpersonal functioning, the latter with sustained effectiveness 6 weeks after the class was ended. Controls showed marked deteriorations in those areas. The Tai-chi group also experienced fewer disruptions to life activities at the 6-week maintenance. There was no significant improvement in negative symptoms after Tai-chi. Conclusions. This study demonstrated encouraging benefits of Tai-chi in preventing deteriorations in movement coordination and interpersonal functioning for residential patients with schizophrenia. The ease of implementation facilitates promotion at institutional psychiatric services.

The effect of tai chi exercise on quality of life in hemodialysis patients

PubMed Central

Shahgholian, Nahid; Eshghinezhad, Ameneh; Mortazavi, Mojgan

2014-01-01

Background: Today, despite remarkable advances in the care of hemodialysis patients, the quality of life (QOL) for these patients is still unsatisfactory. Although previous reports confirmed the effect of exercise on the well-being of renal patients, less than 50% of end-stage kidney patients participate in a regular sports program. Tai chi is a slow and gentle exercise that is suitable for people with chronic illnesses and those with severe intolerance of exercise. Therefore, this study aimed to determine the effect of tai chi exercise on the QOL of hemodialysis patients. Materials and Methods: This was a quasi-experimental study conducted in a single group and in two steps. Twenty-five hemodialysis patients, admitted to hospitals in Isfahan, Iran, were selected, and their QOL was compared before and after intervention in two domains of satisfaction and importance. Convenience sampling was used. The sampling was convenience. The subjects were trained in the intervention through a single session of tai chi exercise class for one hour weekly, for 12 weeks, with a training compact disc (CD) that helped the patients to exercise at least twice a week at home. Data were collected by the completion of a demographic characteristics form and a researcher-made QOL questionnaire adopted from Ferrans and Powers Quality of Life Index Dialysis Version and the Kidney Disease Quality of Life-Short Form (KDQOL-SF) questionnaire by the researchers. The data were analyzed by a paired t-test through SPSS software version 18. Results: Data analysis showed that there was a statistically significant difference in health and functioning (P < 0.001), socioeconomic (P < 0.001), and psychospiritual (P < 0.001) dimensions, and the family dimension had P = 0.002 in the satisfaction domain and P = 0.008 in the importance domain; the total score of quality of life in both domains was P < 0.001. Conclusions: According to the research findings, tai chi exercise improves the QOL score

Patient Engagement in Randomized Controlled Tai Chi Clinical Trials among the Chronically Ill.

PubMed

Jiang, Dongsheng; Kong, Weihong; Jiang, Joanna J

2017-01-01

Physicians encounter various symptom-based complaints each day. While physicians strive to support patients with chronic illnesses, evidence indicates that patients who are actively involved in their health care have better health outcomes and sometimes lowers costs. This article is to analyze how patient engagement is described when complex interventions such as Tai Chi were delivered in Randomized Controlled clinical Trials (RCTs). It reviews the dynamic patient- physician relationship in chronic illness management and to illustrate the patient engagement process, using Tai Chi as an example intervention. RCTs are considered the gold standard in clinical research. This study is a qualitative analysis of RCTs using Tai Chi as an intervention. A systematic literature search was performed to identify quality randomized controlled clinical trials that investigated the effects of Tai Chi. Selected clinical trials were classified according to research design, intervention style, patient engagement, and outcomes. Patient engagement was classified based on levels of patient participation, compliance, and selfmanagement. The chronic health conditions included in this paper are Parkinson's disease, polyneuropathy, hypertension, stroke, chronic insomnia, chronic heart failure, fibromyalgia, osteoarthritis, central obesity, depression, deconditioning in the elderly, or being pre-clinically disabled. We found that patient engagement, as a concept, was not well defined in literature. It covers a wide range of related terms, such as patient involvement, participation, shared decision- making, patient activation, adherence, compliance, and self-management. Tai Chi, as a very complex practice system, is to balance all aspects of a patient's life; however, the level of patient engagement is difficult to describe using conventional clinical trial design. To accurately illustrate the effect of a complex intervention, novel research design must explore ways to measure patient

Autosomal STRs provide genetic evidence for the hypothesis that Tai people originate from southern China.

PubMed

Sun, Hao; Zhou, Chi; Huang, Xiaoqin; Lin, Keqin; Shi, Lei; Yu, Liang; Liu, Shuyuan; Chu, Jiayou; Yang, Zhaoqing

2013-01-01

Tai people are widely distributed in Thailand, Laos and southwestern China and are a large population of Southeast Asia. Although most anthropologists and historians agree that modern Tai people are from southwestern China and northern Thailand, the place from which they historically migrated remains controversial. Three popular hypotheses have been proposed: northern origin hypothesis, southern origin hypothesis or an indigenous origin. We compared the genetic relationships between the Tai in China and their "siblings" to test different hypotheses by analyzing 10 autosomal microsatellites. The genetic data of 916 samples from 19 populations were analyzed in this survey. The autosomal STR data from 15 of the 19 populations came from our previous study (Lin et al., 2010). 194 samples from four additional populations were genotyped in this study: Han (Yunnan), Dai (Dehong), Dai (Yuxi) and Mongolian. The results of genetic distance comparisons, genetic structure analyses and admixture analyses all indicate that populations from northern origin hypothesis have large genetic distances and are clearly differentiated from the Tai. The simulation-based ABC analysis also indicates this. The posterior probability of the northern origin hypothesis is just 0.04 [95%CI: (0.01-0.06)]. Conversely, genetic relationships were very close between the Tai and populations from southern origin or an indigenous origin hypothesis. Simulation-based ABC analyses were also used to distinguish the southern origin hypothesis from the indigenous origin hypothesis. The results indicate that the posterior probability of the southern origin hypothesis [0.640, 95%CI: (0.524-0.757)] is greater than that of the indigenous origin hypothesis [0.324, 95%CI: (0.211-0.438)]. Therefore, we propose that the genetic evidence does not support the hypothesis of northern origin. Our genetic data indicate that the southern origin hypothesis has higher probability than the other two hypotheses statistically

To Your Health: NLM update transcript - Fibromyalgia and tai chi

MedlinePlus

... for 24 weeks - or six months, reported more comparative benefits than peers who left the exercise program ... and fitness. While some previous studies suggested a comparative benefit of tai chi for fibromyalgia patients, the ...

Relationships between flow experience, IKIGAI, and sense of coherence in Tai chi practitioners.

PubMed

Iida, Kenji; Oguma, Yuko

2013-01-01

The purpose of this study was to examine the mental health effects of Tai chi on regular practitioners by investigating the relationships between flow experience, IKIGAI (Japanese: "Life worth living"), and sense of coherence. The results indicated that flow experience may influence IKIGAI and IKIGAI may influence sense of coherence; this suggests that IKIGAI may act as an intermediary between flow experience and sense of coherence. The results also indicated that the longer the Tai chi experience, the higher was the flow experience.

Mindfulness-based interventions in multiple sclerosis: beneficial effects of Tai Chi on balance, coordination, fatigue and depression

PubMed Central

2014-01-01

Background Patients suffering from Multiple Sclerosis (MS) experience a wide array of symptoms, including balance problems, mobility impairment, fatigue and depression. Physical exercise has recently been acknowledged as a treatment option complementary to medication. However, information regarding putative effects of structured exercise programs on neurological symptoms is sparse. Tai Chi, a Chinese martial art incorporating physical exercise and mindfulness training, has been shown to yield health benefits in various neurological groups. It seems particularly suitable for patients with motoric deficits as it challenges coordination and balance. The purpose of the current study was to explore the therapeutic value of structured Tai Chi training for coordination, balance, fatigue and depression in mildly disabled MS patients. Methods A sample of 32 MS patients (Expanded Disability Status Scale, EDSS < 5) was examined. A structured Tai Chi course was devised and a Tai Chi group participated in two weekly sessions of 90 minutes duration for six months, while a comparison group received treatment as usual (TAU). Both groups were examined prior to and following the six-months interval with regards to balance and coordination performance as well as measures of fatigue, depression and life satisfaction. Results Following the intervention, the Tai Chi group showed significant, consistent improvements in balance, coordination, and depression, relative to the TAU group (range of effect-sizes: partial η2 = 0.16 – 0.20). Additionally, life satisfaction improved (partial η2 = 0.31). Fatigue deteriorated in the comparison group, whereas it remained relatively stable in the Tai Chi group (partial η2 = 0.24). Conclusions The consistent pattern of results confirms that Tai Chi holds therapeutic potential for MS patients. Further research is needed to determine underlying working mechanisms, and to verify the results in a larger sample and different MS

[A randomized, double-blind, controlled study: Ji-Tai tablet for the treatment of acute withdrawl syndrome of mild heroin dependence].

PubMed

Wang, Yuhong; Tang, Cuiqing; Cheng, Shuang; Cui, Guimei; Zhang, Ruiling; Zhang, Zhiyong; Xie, Lingyin; Lin, Yongxiong; Hao, Wei

2015-02-01

To investigate the efficacy and safety of Ji-Tai tablet and Ji-Tai tablet combined with buprenorphine in the treatment of patients with acute withdrawal syndrome of mild heroin dependence. A total of 150 patients with mild heroin dependence were recruited, and were randomly assigned to a Ji-Tai tablet group (n=50), a Ji-Tai tablet combined with buprenorphine group (n=50) and a control group (n=50) during a 10-day clinical trial. Opiate withdrawal scale (OWS) was used to measure the severity of withdrawal symptoms. Anxiety symptoms assessments were made at 0 day (baseline), the day 5 (middle), and the day 10 (end) by the Hamilton anxiety scale (HAMA). Symptoms were assessed before and 1 h or 2 h after medication each day. The total withdrawal symptoms scores and the daily reduction rate were used to measure the effect of Ji-Tai tablet vs Ji- Tai tablet plus buprenorphine. Safety evaluation was carried out by the following measures: baseline of treatment, drug side effects after the treatment, vital signs (blood pressure, heart rate, and respiration rate), laboratory examination (routine blood and urine tests and the liver and kidney function tests), and electrocardiograms. A total of 142 mild heroin dependence patients performed the experiments (including 48 in the Ji-Tai tablet group, 48 in the Ji-Tai tablet with buprenorphine group and 46 in the control group). The scores of baseline withdrawal symptoms were 43.520±19.786, 42.640±17.648 and 47.100±24.450, respectively, with no significant differences among the 3 groups (all P>0.05 ). During the 10-day treatment, the reduction rate of acute withdrawal symptoms scores increased daily, the acute withdrawal syndrome scores and the anxiety symptoms scores declined from day 0 to day 10, there was also no significant difference among the 3 groups (all P>0.05). Ji-Tai tablet did not affect vital signs such as blood pressure, heart rate, and respiration rate. Ji-Tai tablet or Ji-Tai tablet combined with buprenorphine

Reduced Cognitive-Motor Interference on Voluntary Balance Control in Older Tai Chi Practitioners.

PubMed

Varghese, Rini; Hui-Chan, Christina W Y; Bhatt, Tanvi

2016-01-01

Recent dual-task studies suggest that Tai Chi practitioners displayed better control of standing posture and maintained a quicker response time of postural muscle activation during a stepping down activity. Whether this effect extends to voluntary balance control, specifically the limits of excursion of the center of pressure, remains to be examined. The purpose of this study was to evaluate the cognitive-motor interference pattern by examining the effects of a concurrently performed cognitive task on attention of voluntary balance control in older adults who are long-term practitioners of Tai Chi. Ten older Tai Chi practitioners and 10 age-matched nonpractitioners performed a voluntary balance task that required them to shift their weight to reach a preset target in the forward and backward directions, with (single task, ST) and without (dual task, DT) a secondary cognitive task, which was the counting backward task. The counting backward task required the individual to compute and verbalize a series of arithmetic differences between a given pair of randomly generated numbers. The cognitive task was also performed independently (cognitive-ST). All trials were performed in a random order. Balance outcomes included reaction time, movement velocity, and maximal excursion of the center of pressure provided by the NeuroCom system. Cognitive outcome was the number of correct responses generated within the 8-second trial during the ST and DT conditions. Outcome variables were analyzed using a 2-factor, group by task, analysis of variance. DT costs for the variables were calculated as the relative difference between ST and DT conditions and were compared between the 2 groups using independent t tests. Tai Chi practitioners displayed shorter reaction times (P < .001) and faster movement velocities (P < .05) of their center of pressure than older nonpractitioners for both directions; however, no difference was found between the maximal excursions of the 2 groups. Cost

The Effects of Tai Chi and Neck Exercises in the Treatment of Chronic Nonspecific Neck Pain: A Randomized Controlled Trial.

PubMed

Lauche, Romy; Stumpe, Christoph; Fehr, Johannes; Cramer, Holger; Cheng, Ying Wu; Wayne, Peter M; Rampp, Thomas; Langhorst, Jost; Dobos, Gustav

2016-09-01

This study aimed to test the efficacy of Tai Chi for treating chronic neck pain. Subjects with chronic nonspecific neck pain were randomly assigned to 12 weeks of group Tai Chi or conventional neck exercises with weekly sessions of 75 to 90 minutes, or a wait-list control. The primary outcome measure was pain intensity (visual analogue scale). Secondary outcomes included pain on movement, functional disability, quality of life, well-being and perceived stress, postural and interoceptive awareness, satisfaction, and safety. Altogether, 114 participants were included (91 women, 49.4 ± 11.7 years of age). After 12 weeks Tai Chi participants reported significantly less pain compared with the wait list group (average difference in mm on the visual analogue scale: -10.5; 95% confidence interval, -20.3 to -.9; P = .033). Group differences were also found for pain on movement, functional disability, and quality of life compared with the wait list group. No differences were found for Tai Chi compared with neck exercises. Patients' satisfaction with both exercise interventions was high, and only minor side effects were observed. Tai Chi was more effective than no treatment in improving pain in subjects with chronic nonspecific neck pain. Because Tai Chi is probably as effective as neck exercises it may be considered a suitable alternative to conventional exercises for those with a preference toward Tai Chi. This article presents results of a randomized controlled trial comparing Tai Chi, conventional neck exercises, and no treatment for chronic nonspecific neck pain. Results indicate that Tai Chi exercises and conventional neck exercises are equally effective in improving pain and quality of life therefore representing beneficial interventions for neck pain. Copyright © 2016 American Pain Society. Published by Elsevier Inc. All rights reserved.

The effects of Tai Chi on physical and psychosocial function among persons with multiple sclerosis: A systematic review.

PubMed

Taylor, Emily; Taylor-Piliae, Ruth E

2017-04-01

Conduct a systematic review to evaluate the effects of Tai Chi on physical and psychosocial function among individuals with Multiple Sclerosis. An electronic literature search of 12 databases using controlled vocabulary function and keywords from inception through August 2016. All Tai Chi intervention studies assessing physical and psychosocial function among persons with Multiple Sclerosis were included. Study quality was scored using an established tool examining 16 study elements (range=0-32). A total of 91 articles were retrieved, with 3 additional articles identified through reviewing bibliographies of relevant articles. A total of 8 studies (randomized controlled trials, n=3; quasi-experimental, n=5) enrolled 193 participants with Multiple Sclerosis. Studies were conducted in the USA (n=3), Europe (n=3), Iran, (n=1), and India (n=1). A total of 3 studies reported using the Yang style of Tai Chi (not specified, n=5 studies). The Tai Chi intervention averaged 27 sessions over 11 weeks. Study quality scores for the randomized controlled trials had a mean score of 23 (range 19-26), while quality scores for quasi-experimental studies had a mean score of 20 (range 13-26). Overall, participants enrolled in Tai Chi had better balance, gait and flexibility, less fatigue and depression, and better quality of life after the intervention; though mixed results were reported. The results indicate that Tai Chi is likely safe and may provide physical and psychosocial benefits in individuals with Multiple Sclerosis. Further research is needed using more rigorous study designs to assess the benefits of Tai Chi for individuals with Multiple Sclerosis. Copyright © 2017 Elsevier Ltd. All rights reserved.

The effects of Tai Chi on physical function and well-being among persons with Parkinson's Disease: A systematic review.

PubMed

Ćwiękała-Lewis, Klaudia J; Gallek, Matthew; Taylor-Piliae, Ruth E

2017-04-01

Current medical treatments for Parkinson's disease (PD) are mainly palliative, though research indicates Tai Chi exercise improves physical function and well-being. An electronic database search of PubMed, CINAHL, Web of Science, Cochrane Library, PsycINFO and Embase was conducted, to examine current scientific literature for potential benefits of Tai Chi on physical function and well-being among persons with PD. A total of 11 studies met the inclusion criteria: 7 randomized clinical trials and 4 quasi-experimental studies. PD participants (n = 548) were on average age 68 years old and 50% women. Overall, participants enrolled in Tai Chi had better balance and one or more aspect of well-being, though mixed results were reported. Further research is needed with more rigorous study designs, larger sample sizes, adequate Tai Chi exercise doses, and carefully chosen outcome measures that assess the mechanisms as well as the effects of Tai Chi, before widespread recommendations can be made. Copyright © 2016 Elsevier Ltd. All rights reserved.

A systematic review of the health benefits of Tai Chi for students in higher education.

PubMed

Webster, Craig S; Luo, Anna Y; Krägeloh, Chris; Moir, Fiona; Henning, Marcus

2016-06-01

The poor health consequences of stress are well recognized, and students in higher education may be at particular risk. Tai Chi integrates physical exercise with mindfulness techniques and seems well suited to relieve stress and related conditions. We conducted a systematic review of the health benefits of Tai Chi for students in higher education reported in the English and Chinese literature, using an evidence hierarchy approach, allowing the inclusion of studies additional to randomized controlled trials. Sixty eight reports in Chinese and 8 in English were included - a combined study sample of 9263 participants. Eighty one health outcomes were extracted from reports, and assigned evidence scores according to the evidence hierarchy. Four primary and eight secondary outcomes were found. Tai Chi is likely to benefit participants by increasing flexibility, reducing symptoms of depression, decreasing anxiety, and improving interpersonal sensitivity (primary outcomes). Secondary outcomes include improved lung capacity, balance, 800/1000m run time, quality of sleep, symptoms of compulsion, somatization and phobia, and decreased hostility. Our results show Tai Chi yields psychological and physical benefits, and should be considered by higher education institutions as a possible means to promote the physical and psychological well-being of their students.

Fall Risk-Relevant Functional Mobility Outcomes in Dementia Following Dyadic Tai Chi Exercise

PubMed Central

Yao, Lan; Giordani, Bruno J.; Algase, Donna L.; You, Mei; Alexander, Neil B.

2012-01-01

Whether persons with dementia benefit from fall prevention exercise is unclear. Applying the Positive Emotion-Motivated Tai Chi protocol, preliminary findings concerning adherence and effects of a dyadic Tai Chi exercise program on persons with Alzheimer’s disease (AD) are reported. Using pre/ posttest design, 22 community-dwelling AD-caregiver dyads participated in the program. Fall-risk-relevant functional mobility was measured using Unipedal Stance Time (UST) and Timed Up and Go (TUG) tests. Results showed that 19/22 (86.4%) AD patients completed the 16-week program and final assessment; 16/19 dyads (84.2%) completed the prescribed home program as reported by caregivers. UST adjusted mean improved from 4.0 to 5.1 (Week 4, p < .05) and 5.6 (Week 16, p < .05); TUG improved from 13.2 to 11.6 (Week 4, p < .05) and 11.6 (Week 16, p > .05) post intervention. Retaining dementia patients in an exercise intervention remains challenging. The dyadic Tai Chi approach appears to succeed in keeping AD-caregiver dyads exercising and safe. PMID:22517441

Fall risk-relevant functional mobility outcomes in dementia following dyadic tai chi exercise.

PubMed

Yao, Lan; Giordani, Bruno J; Algase, Donna L; You, Mei; Alexander, Neil B

2013-03-01

Whether persons with dementia benefit from fall prevention exercise is unclear. Applying the Positive Emotion-Motivated Tai Chi protocol, preliminary findings concerning adherence and effects of a dyadic Tai Chi exercise program on persons with Alzheimer's disease (AD) are reported. Using pre/posttest design, 22 community-dwelling AD-caregiver dyads participated in the program. Fall-risk-relevant functional mobility was measured using Unipedal Stance Time (UST) and Timed Up and Go (TUG) tests. Results showed that 19/22 (86.4%) AD patients completed the 16-week program and final assessment; 16/19 dyads (84.2%) completed the prescribed home program as reported by caregivers. UST adjusted mean improved from 4.0 to 5.1 (Week 4, p < .05) and 5.6 (Week 16, p < .05); TUG improved from 13.2 to 11.6 (Week 4, p < .05) and 11.6 (Week 16, p > .05) post intervention. Retaining dementia patients in an exercise intervention remains challenging. The dyadic Tai Chi approach appears to succeed in keeping AD-caregiver dyads exercising and safe.

Feasibility, qualitative findings and satisfaction of a brief Tai Chi mind–body programme for veterans with post-traumatic stress symptoms

PubMed Central

Niles, Barbara L; Mori, DeAnna L; Polizzi, Craig P; Pless Kaiser, Anica; Ledoux, Annie M; Wang, Chenchen

2016-01-01

Objective To examine feasibility, qualitative feedback and satisfaction associated with a 4-session introduction to Tai Chi for veterans with post-traumatic stress symptoms. Design We observed and reported recruitment and retention rates, participant characteristics, adherence, and satisfaction across 2 cohorts. We also examined qualitative feedback provided by questionnaires, focus groups and individual interviews. Main outcome measures Rates of recruitment and retention, focus group and individual feedback interviews, self-reported satisfaction. Participants 17 veterans with post-traumatic stress symptoms. Results Almost 90% (17/19) of those eligible following the telephone screen enrolled in the programme. Three-quarters (76.4%) of the participants attended at least 3 of the 4 Tai Chi sessions. Qualitative data analysis revealed themes indicating favourable impressions of the Tai Chi sessions. In addition, participants reported feeling very engaged during the sessions, and found Tai Chi to be helpful for managing distressing symptoms (ie, intrusive thoughts, concentration difficulties, physiological arousal). Participants also reported high satisfaction: 93.8% endorsed being very or mostly satisfied with the programme. All participants (100%) indicated that they would like to participate in future Tai Chi programmes and would recommend it to a friend. Conclusions Tai Chi appears to be feasible and safe for veterans with symptoms of post-traumatic stress disorder (PTSD), is perceived to be beneficial and is associated with high rates of satisfaction. This study highlights the need for future investigation of Tai Chi as a novel intervention to address symptoms of PTSD. PMID:27899398

The story of the evolution of a unique tai chi form: origins, philosophy, and research.

PubMed

Robins, Jo Lynne W; Elswick, R K; McCain, Nancy L

2012-09-01

The purpose of this article is to introduce a unique tai chi form that has been successfully implemented in two large randomized clinical trials. The intervention is composed of a series of tai chi movements chosen for their particular meanings, thus adding a cognitive component to the practice of a moving meditation. Over the last decade, the intervention has continued to evolve as it has been used in different populations. Most recently, medical qigong has been integrated to strengthen its potential impact on a variety of biobehavioral measures associated with cardiometabolic risk in women. Following an appraisal of the authors' process as well as the philosophy, practice, and research of tai chi and qigong, the authors share the story of their intervention to contribute to the evolving research of these safe, well-received, low-cost, and beneficial practices.

Seated T'ai Chi in Older Taiwanese People Using Wheelchairs: A Randomized Controlled Trial Investigating Mood States and Self-Efficacy.

PubMed

Hsu, Chen-Yuan; Moyle, Wendy; Cooke, Marie; Jones, Cindy

2016-12-01

There is growing interest in t'ai chi, but little research has addressed whether t'ai chi is effective in older people using wheelchairs for mobilization. The aim of this study was to compare the effects of seated t'ai chi exercise and usual standard activities on mood states and self-efficacy in older people living in a long-term care facility and using wheelchairs for mobilization. Randomized controlled trial (trial registration no. ACTRN12613000029796). One long-term-care facility in Taiwan. Sixty participants were randomly assigned by a computer-generated random sequence to a t'ai chi group (n = 30) or a usual exercise and entertainment activities group (n = 30). Seated t'ai chi exercise for 40 minutes three times a week for 26 weeks was provided. Mood states (Profile of Mood States Short Form [POMS-SF]) and self-efficacy (Self-Efficacy for Exercise [SEE]). At week 26, participants in the t'ai chi group reported significantly lower mood states on the fatigue-inertia dimension of the POMS-SF (mean score ± standard deviation, 3.56 ± 3.71) than did the control group (mean score, 7.16 ± 6.36) (F [1, 58] = 7.15; p < 0.05). The t'ai chi group recorded significantly higher SEE levels (mean, 35.66 ± 36.83) than did those in the control group (mean, 15.30 ± 26.43) (F [1, 58] = 6.05; p < 0.05). The findings highlight the importance of t'ai chi for a reduction in the fatigue-inertia mood state and an increase in self-efficacy for older people using wheelchairs.

Translation of an Effective Tai Chi Intervention Into a Community-Based Falls-Prevention Program

PubMed Central

Li, Fuzhong; Harmer, Peter; Glasgow, Russell; Mack, Karin A.; Sleet, David; Fisher, K. John; Kohn, Melvin A.; Millet, Lisa M.; Mead, Jennifer; Xu, Junheng; Lin, Mei-Li; Yang, Tingzhong; Sutton, Beth; Tompkins, Yvaughn

2008-01-01

Tai Chi—Moving for Better Balance, a falls-prevention program developed from a randomized controlled trial for community-based use, was evaluated with the RE-AIM framework in 6 community centers. The program had a 100% adoption rate and 87% reach into the target older adult population. All centers implemented the intervention with good fidelity, and participants showed significant improvements in health-related outcome measures. This evidence-based tai chi program is practical to disseminate and can be effectively implemented and maintained in community settings. PMID:18511723

The influence of Tai Chi training on the center of pressure trajectory during gait initiation in older adults.

PubMed

Hass, Chris J; Gregor, Robert J; Waddell, Dwight E; Oliver, Alanna; Smith, Dagan W; Fleming, Richard P; Wolf, Steven L

2004-10-01

To determine if a program of intense Tai Chi exercise that has been shown to reduce the risk of falling in older adults improves postural control by altering the center of pressure (COP) trajectory during gait initiation. Before-after trial. Biomechanics research laboratory. Twenty-eight older adults transitioning to frailty who participated in either a 48-week intervention of intense Tai Chi training or a wellness education (WE) program. Eight Tai Chi forms emphasizing trunk rotation, weight shifting, coordination, and narrowing of lower-extremity stance were taught twice weekly. WE program participants met once a week and received lectures focused on health. Main outcome measures The COP was recorded during gait initiation both before and after the 48-week intervention by using a forceplate sampling at 300 Hz. The COP trajectory was divided into 3 periods (S1, S2, S3) by identifying 2 landmark events. Displacement and average velocity of the COP trace in the anteroposterior (x) and mediolateral (y) directions, as well as smoothness, were calculated. Tai Chi training increased the posterior displacement of the COP during S1 and improved the smoothness of the COP during S2. Tai Chi improved the mechanism by which forward momentum is generated and improved coordination during gait initiation, suggesting improvements in postural control.

A randomized controlled trial of 8-form Tai chi improves symptoms and functional mobility in fibromyalgia patients.

PubMed

Jones, Kim D; Sherman, Christy A; Mist, Scott D; Carson, James W; Bennett, Robert M; Li, Fuzhong

2012-08-01

Previous researchers have found that 10-form Tai chi yields symptomatic benefit in patients with fibromyalgia (FM). The purpose of this study was to further investigate earlier findings and add a focus on functional mobility. We conducted a parallel-group randomized controlled trial FM-modified 8-form Yang-style Tai chi program compared to an education control. Participants met in small groups twice weekly for 90 min over 12 weeks. The primary endpoint was symptom reduction and improvement in self-report physical function, as measured by the Fibromyalgia Impact Questionnaire (FIQ), from baseline to 12 weeks. Secondary endpoints included pain severity and interference (Brief Pain Inventory (BPI), sleep (Pittsburg sleep Inventory), self-efficacy, and functional mobility. Of the 101 randomly assigned subjects (mean age 54 years, 93 % female), those in the Tai chi condition compared with the education condition demonstrated clinically and statistically significant improvements in FIQ scores (16.5 vs. 3.1, p = 0.0002), BPI pain severity (1.2 vs. 0.4, p = 0.0008), BPI pain interference (2.1 vs. 0.6, p = 0.0000), sleep (2.0 vs. -0.03, p = 0.0003), and self-efficacy for pain control (9.2 vs. -1.5, p = 0.0001). Functional mobility variables including timed get up and go (-.9 vs. -.3, p = 0.0001), static balance (7.5 vs. -0.3, p    0.0001), and dynamic balance (1.6 vs. 0.3, p = 0.0001) were significantly improved with Tai chi compared with education control. No adverse events were noted. Twelve weeks of Tai chi, practice twice weekly, provided worthwhile improvement in common FM symptoms including pain and physical function including mobility. Tai chi appears to be a safe and an acceptable exercise modality that may be useful as adjunctive therapy in the management of FM patients. (ClinicalTrials.gov Identifier, NCT01311427).

Tai Chi Improves Sleep Quality in Healthy Adults and Patients with Chronic Conditions: A Systematic Review and Meta-analysis

PubMed Central

Raman, Gowri; Zhang, Yuan; Minichiello, Vincent J; D'Ambrosio, Carolyn M.; Wang, Chenchen

2017-01-01

Background Physical activity and exercise appear to improve sleep quality. However, the quantitative effects of Tai Chi on sleep quality in the adult population have rarely been examined. We conducted a systematic review and meta-analysis evaluating the effects of Tai Chi on sleep quality in healthy adults and disease populations. Methods Medline, Cochrane Central databases, and review of references were searched through July 31, 2013. English-language studies of all designs evaluating Tai Chi’s effect on sleep outcomes in adults were examined. Data were extracted and verified by 2 reviewers. Extracted information included study setting and design, population characteristics, type and duration of interventions, outcomes, risk of bias and main results. Random effect models meta-analysis was used to assess the magnitude of treatment effect when at least 3 trials reported on the same sleep outcomes. Results Eleven studies (9 randomized and 2 non-randomized trials) totaling 994 subjects published between 2004 and 2012 were identified. All studies except one reported Pittsburg Sleep Quality Index. Nine randomized trials reported that 1.5 to 3 hour each week for a duration of 6 to 24 weeks of Tai Chi significantly improved sleep quality (Effect Size, 0.89; 95% confidence interval [CI], 0.28 to 1.50), in community-dwelling healthy participants and in patients with chronic conditions. Improvement in health outcomes including physical performance, pain reduction, and psychological well-being occurred in the Tai Chi group compared with various controls. Limitations Studies were heterogeneous and some trials were lacking in methodological rigor. Conclusions Tai Chi significantly improved sleep quality in both healthy adults and patients with chronic health conditions, which suggests that Tai Chi may be considered as an alternative behavioral therapy in the treatment of insomnia. High-quality, well-controlled randomized trials are needed to better inform clinical decisions

Effects of T'ai Chi exercise on fibromyalgia symptoms and health-related quality of life.

PubMed

Taggart, Helen M; Arslanian, Christine L; Bae, Sejong; Singh, Karan

2003-01-01

Fibromyalgia (FM), one of the most common musculoskeletal disorders, is associated with high levels of impaired health and inadequate or limited symptom relief. The cause of this complex syndrome is unknown, and there is no known cure. Numerous research results indicate that a combination of physical exercise and mind-body therapy is effective in symptom management. T'ai Chi, an ancient Chinese exercise, combines physical exercise with mindbody therapy. To investigate the effects of T'ai Chi exercise on FM symptoms and health-related quality of life. Pilot study, one group pre-to-post posttest design. Participants with FM (n = 39) formed a single group for 6 weeks of 1-hour, twice weekly T'ai Chi exercise classes. FM symptoms and health-related quality of life were measured before and after exercise. Twenty-one participants completed at least 10 of the 12 exercise sessions. Although the dropout rate was higher than expected, measurements on both the Fibromyalgia Impact Questionnaire (FIQ) (Buckhardt, Clark, & Bennett, 1991) and the Short Form-36 (SE-36) (Ware & Sherbourne, 1992) revealed statistically significant improvement in symptom management and health-related quality of life. Knowledge of interventions to enhance health for the patient with musculoskeletal problems is a National Association of Orthopaedic Nurses priority. Tai Chi is potentially beneficial to patients with FM. Further research is needed to support evidence-based practice.

Effects of Tai Chi on Cognition and Fall Risk in Older Adults with Mild Cognitive Impairment: A Randomized Controlled Trial.

PubMed

Sungkarat, Somporn; Boripuntakul, Sirinun; Chattipakorn, Nipon; Watcharasaksilp, Kanokwan; Lord, Stephen R

2017-04-01

To examine whether combined center- and home-based Tai Chi training can improve cognitive ability and reduce physiological fall risk in older adults with amnestic mild cognitive impairment (a-MCI). Randomized controlled trial. Chiang Mai, Thailand. Adults aged 60 and older who met Petersen's criteria for multiple-domain a-MCI (N = 66). Three weeks center-based and 12 weeks home-based Tai Chi (50 minutes per session, 3 times per week). Cognitive tests, including Logical Memory (LM) delayed recall, Block Design, Digit Span forward and backward, and Trail-Making Test Part B-A (TMT B-A), and fall risk index using the Physiological Profile Assessment (PPA). At the end of the trial, performance on LM, Block Design, and TMT B-A were significantly better for the Tai Chi group than the control group after adjusting for baseline test performance. The Tai Chi group also had significantly better composite PPA score and PPA parameter scores: knee extension strength, reaction time, postural sway, and lower limb proprioception. Combined center- and home-based Tai Chi training three times per week for 15 weeks significantly improved cognitive function and moderately reduced physiological fall risk in older adults with multiple-domain a-MCI. Tai Chi may be particularly beneficial to older adults with this condition. © 2016, Copyright the Authors Journal compilation © 2016, The American Geriatrics Society.

Physical activity for osteoarthritis management: a randomized controlled clinical trial evaluating hydrotherapy or Tai Chi classes.

PubMed

Fransen, Marlene; Nairn, Lillias; Winstanley, Julie; Lam, Paul; Edmonds, John

2007-04-15

To determine whether Tai Chi or hydrotherapy classes for individuals with chronic symptomatic hip or knee osteoarthritis (OA) result in measurable clinical benefits. A randomized controlled trial was conducted among 152 older persons with chronic symptomatic hip or knee OA. Participants were randomly allocated for 12 weeks to hydrotherapy classes (n = 55), Tai Chi classes (n = 56), or a waiting list control group (n = 41). Outcomes were assessed 12 and 24 weeks after randomization and included pain and physical function (Western Ontario and McMaster Universities Osteoarthritis Index), general health status (Medical Outcomes Study Short Form 12 Health Survey [SF-12], version 2), psychological well-being, and physical performance (Up and Go test, 50-foot walk time, timed stair climb). At 12 weeks, compared with controls, participants allocated to hydrotherapy classes demonstrated mean improvements (95% confidence interval) of 6.5 (0.4, 12.7) and 10.5 (3.6, 14.5) for pain and physical function scores (range 0-100), respectively, whereas participants allocated to Tai Chi classes demonstrated improvements of 5.2 (-0.8, 11.1) and 9.7 (2.8, 16.7), respectively. Both class allocations achieved significant improvements in the SF-12 physical component summary score, but only allocation to hydrotherapy achieved significant improvements in the physical performance measures. All significant improvements were sustained at 24 weeks. In this almost exclusively white sample, class attendance was higher for hydrotherapy, with 81% attending at least half of the available 24 classes, compared with 61% for Tai Chi. Access to either hydrotherapy or Tai Chi classes can provide large and sustained improvements in physical function for many older, sedentary individuals with chronic hip or knee OA.

Detection of Outliers in TWSTFT Data Used in TAI

DTIC Science & Technology

2009-11-01

41st Annual Precise Time and Time Interval (PTTI) Meeting 421 DETECTION OF OUTLIERS IN TWSTFT DATA USED IN TAI A...data in two-way satellite time and frequency transfer ( TWSTFT ) time links. In the case of TWSTFT data used to calculate International Atomic Time...data; that TWSTFT links can show an underlying slope which renders the standard treatment more difficult. Using phase and frequency filtering

Psychological effects of Tai Chi Chuan.

PubMed

Jimenez, P J; Melendez, A; Albers, U

2012-01-01

This article reviews the scientific studies which have been carried out at the international level on the psychological benefits that Tai Chi Chuan (TCC) brings to those who practice it. It analyzes the framework in which the research was performed, the real benefits that this activity achieves and their causes. The present article brings a new analytical perspective to the reviews carried out to date in regard to classifying and analyzing the psychological variables involved in the practice of TCC and offers a homogeneous framework within which to develop research in this field based on the model proposed by Spirduso et al. (2005). Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

What Do We Really Know About the Safety of Tai Chi?: A Systematic Review of Adverse Event Reports in Randomized Trials

PubMed Central

Wayne, Peter M.; Berkowitz, Danielle L.; Litrownik, Daniel E.; Buring, Julie E.; Yeh, Gloria Y.

2014-01-01

Objective Systematically review frequency and quality of adverse event (AE) reports in randomized clinical trials (RCTs) of Tai Chi (TC). Data Sources Electronic searches of PubMed/MEDLINE and additional databases from inception through March 2013 of English-language RCTs. Search terms were tai chi, taiji, tai chi chuan. Data were independently extracted by two investigators. Study Selection We included all available randomized controlled trials (RCTs) that were published in English and used Tai Chi as an intervention. Inclusion and exclusion of studies were reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Data Extraction Eligible RCTs were categorized with respect to AE reporting: 1) No mention of protocols for monitoring AEs or reports of AEs; 2) Reports of AEs either with or without explicit protocols for monitoring AEs. Data Synthesis 153 eligible RCTs were identified, most targeting older adults. Only 50 eligible trials (33%) included reporting of AEs, and of these, only 18 trials (12% overall) also reported an explicit AE monitoring protocol. Protocols varied with respect to rigor of systematic monitoring in both Tai Chi and comparison groups. Reported AEs were typically minor and expected, and primarily musculoskeletal related (e.g., knee and back pain); no intervention-related serious AEs were reported. Conclusions Tai Chi is unlikely to result in serious adverse events, but may be associated with minor musculoskeletal aches and pains. However, poor and inconsistent reporting of AEs greatly limits the conclusions that can be drawn regarding the safety of Tai Chi. PMID:24878398

[Comparative study of theoretical literature on cold pathogenic disease in Wai tai mi yao fang (Arcane Essentials from the Imperial Library) and Tai ping sheng hui fang (Taiping Holy Prescriptions for Universal Relief)].

PubMed

Zhang, Huirui; Liang, Yongxuan

2014-09-01

In the Wai tai mi yao fang (Arcane Essentials from the Imperial Library) compiled in 752, its portion on cold pathogenic disorders embodies the achievements before the mid Tang Dynasty, whereas that in the Tai ping sheng hui fang (Taiping Holy Prescriptions for Universal Relief), compiled in 992 embodies those before the early Song Dynasty. Comparison on the theory of cold disorders in both books reveal that, during the 2 centuries period from mid Tang to early Song Dynasties, the texts as a carrier for the transmission of such theory in both show no distinct changes, but only with minor revisions and improvements.

Effects of Sun-style Tai Chi exercise on physical fitness and fall prevention in fall-prone older adults.

PubMed

Choi, Jung Hyun; Moon, Jung-Soon; Song, Rhayun

2005-07-01

This paper reports a study to determine changes in the physical fitness (knee and ankle muscle strength, balance, flexibility, and mobility), fall avoidance efficacy, and fall episodes of institutionalized older adults after participating in a 12-week Sun-style Tai Chi exercise programme. Fall prevention has a high priority in health promotion for older people because a fall is associated with serious morbidity in this population. Regular exercise is effective in fall prevention for older adults because of improvements in strength and balance. Tai Chi exercise is considered to offer great potential for health promotion and rehabilitation, particularly in the maintenance of good mental and physical condition in older people. A quasi-experimental design with a non-equivalent control group was used. Data were collected from September 2001 to January 2002. A total of 68 fall-prone older adults with a mean age of 77.8 years participated in the study, and 29 people in the Tai Chi group and 30 controls completed the post-test measures. The Tai Chi exercise programme was provided three times a week for 12 weeks in the experimental group. Data were analysed for group differences using t-tests. At post-test, the experimental group showed significantly improved muscle strength in knee and ankle flexors (P < 0.001) and extensors (P < 0.01), and improved flexibility (P < 0.01) and mobility (P < 0.001) compared with the control group. There was no significant group difference in fall episodes, but the relative risk ratio for the Tai Chi exercise group compared with the control group was 0.62. The experimental group reported significantly more confidence in fall avoidance than did the control group. The findings reveal that Tai Chi exercise programmes can safely improve physical strength and reduce fall risk for fall-prone older adults in residential care facilities.

Increased Hippocampus-Medial Prefrontal Cortex Resting-State Functional Connectivity and Memory Function after Tai Chi Chuan Practice in Elder Adults.

PubMed

Tao, Jing; Liu, Jiao; Egorova, Natalia; Chen, Xiangli; Sun, Sharon; Xue, Xiehua; Huang, Jia; Zheng, Guohua; Wang, Qin; Chen, Lidian; Kong, Jian

2016-01-01

Previous studies provide evidence that aging is associated with the decline of memory function and alterations in the hippocampal (HPC) function, including functional connectivity to the medial prefrontal cortex (mPFC). In this study, we investigated if longitudinal (12-week) Tai Chi Chuan and Baduanjin practice can improve memory function and modulate HPC resting-state functional connectivity (rs-FC). Memory function measurements and resting-state functional magnetic resonance imaging (rs-fMRI) were applied at the beginning and the end of the experiment. The results showed that (1) the memory quotient (MQ) measured by the Wechsler Memory Scale-Chinese Revision significantly increased after Tai Chi Chuan and Baduanjin practice as compared with the control group, and no significant difference was observed in MQ between the Tai Chi Chuan and Baduanjin groups; (2) rs-FC between the bilateral hippocampus and mPFC significantly increased in the Tai Chi Chuan group compared to the control group (also in the Baduanjin group compared to the control group, albeit at a lower threshold), and no significant difference between the Tai Chi Chuan and Baduanjin groups was observed; (3) rs-FC increases between the bilateral hippocampus and mPFC were significantly associated with corresponding memory function improvement across all subjects. Similar results were observed using the left or right hippocampus as seeds. Our results suggest that both Tai Chi Chuan and Baduanjin may be effective exercises to prevent memory decline during aging.

Increased Hippocampus–Medial Prefrontal Cortex Resting-State Functional Connectivity and Memory Function after Tai Chi Chuan Practice in Elder Adults

PubMed Central

Tao, Jing; Liu, Jiao; Egorova, Natalia; Chen, Xiangli; Sun, Sharon; Xue, Xiehua; Huang, Jia; Zheng, Guohua; Wang, Qin; Chen, Lidian; Kong, Jian

2016-01-01

Previous studies provide evidence that aging is associated with the decline of memory function and alterations in the hippocampal (HPC) function, including functional connectivity to the medial prefrontal cortex (mPFC). In this study, we investigated if longitudinal (12-week) Tai Chi Chuan and Baduanjin practice can improve memory function and modulate HPC resting-state functional connectivity (rs-FC). Memory function measurements and resting-state functional magnetic resonance imaging (rs-fMRI) were applied at the beginning and the end of the experiment. The results showed that (1) the memory quotient (MQ) measured by the Wechsler Memory Scale-Chinese Revision significantly increased after Tai Chi Chuan and Baduanjin practice as compared with the control group, and no significant difference was observed in MQ between the Tai Chi Chuan and Baduanjin groups; (2) rs-FC between the bilateral hippocampus and mPFC significantly increased in the Tai Chi Chuan group compared to the control group (also in the Baduanjin group compared to the control group, albeit at a lower threshold), and no significant difference between the Tai Chi Chuan and Baduanjin groups was observed; (3) rs-FC increases between the bilateral hippocampus and mPFC were significantly associated with corresponding memory function improvement across all subjects. Similar results were observed using the left or right hippocampus as seeds. Our results suggest that both Tai Chi Chuan and Baduanjin may be effective exercises to prevent memory decline during aging. PMID:26909038

A randomized controlled trial of 8-form Tai chi improves symptoms and functional mobility in fibromyalgia patients

PubMed Central

Sherman, Christy A.; Mist, Scott D.; Carson, James W.; Bennett, Robert M.; Li, Fuzhong

2017-01-01

Previous researchers have found that 10-form Tai chi yields symptomatic benefit in patients with fibromyalgia (FM). The purpose of this study was to further investigate earlier findings and add a focus on functional mobility. We conducted a parallel-group randomized controlled trial FM-modified 8-form Yang-style Tai chi program compared to an education control. Participants met in small groups twice weekly for 90 min over 12 weeks. The primary endpoint was symptom reduction and improvement in self-report physical function, as measured by the Fibromyalgia Impact Questionnaire (FIQ), from baseline to 12 weeks. Secondary endpoints included pain severity and interference (Brief Pain Inventory (BPI), sleep (Pittsburg sleep Inventory), self-efficacy, and functional mobility. Of the 101 randomly assigned subjects (mean age 54 years, 93 % female), those in the Tai chi condition compared with the education condition demonstrated clinically and statistically significant improvements in FIQ scores (16.5 vs. 3.1, p=0.0002), BPI pain severity (1.2 vs. 0.4, p=0.0008), BPI pain interference (2.1 vs. 0.6, p=0.0000), sleep (2.0 vs. −0.03, p=0.0003), and self-efficacy for pain control (9.2 vs. −1.5, p=0.0001). Functional mobility variables including timed get up and go (−.9 vs. −.3, p=0.0001), static balance (7.5 vs. −0.3, p= 0.0001), and dynamic balance (1.6 vs. 0.3, p=0.0001) were significantly improved with Tai chi compared with education control. No adverse events were noted. Twelve weeks of Tai chi, practice twice weekly, provided worthwhile improvement in common FM symptoms including pain and physical function including mobility. Tai chi appears to be a safe and an acceptable exercise modality that may be useful as adjunctive therapy in the management of FM patients. (ClinicalTrials.gov Identifier, NCT01311427) PMID:22581278

The Effect of T'ai Chi Exercise on Lipid Profiles: A Systematic Review and Meta-Analysis of Randomized Clinical Trials.

PubMed

Alenazi, Aqeel M; Alshehri, Mohammed M; Hoover, Jeffrey C; Yabroudi, Mohammad A; Kachanathu, Shaji John; Liu, Wen

2018-03-01

Cardiovascular disease is a common health problem resulting from many factors, including dyslipidemia. T'ai chi is one of the interventions assigned to improve lipid profiles and other physical outcomes. However, conflicting results might be attributed to different study designs and interventional approaches. A systematic review and meta-analysis are needed to evaluate existing evidence. The aim of this systematic review and meta-analysis is to evaluate existing randomized clinical trials (RCTs) regarding the overall effect of t'ai chi exercise on lipid profiles. Electronic databases (MEDLINE and Cumulative Index to Nursing and Allied Health Literature) were searched. The authors included only English peer reviewed published RCTs that used a t'ai chi intervention and high-density lipoprotein cholesterol (HDL-C) as the primary outcome along with low-density lipoprotein cholesterol (LDL-C) and/or total cholesterol (TC) as secondary outcomes. The authors identified 37 potentially eligible studies. Only eight RCTs were eligible for their qualitative review, and seven studies were eligible for meta-analysis. The included studies were rated as having a low risk of bias. Despite the overall low risk of bias, all studies failed to blind participants to group assignment and were generally unclear about whether they were selectively reporting data. A fixed effect model (I 2  = 38.16%) demonstrated a small positive effect of t'ai chi on HDL-C (Cohen d = 0.12; standard error [SE] = 0.067; p = 0.037). A random effect model demonstrated a medium effect and small effect for LDL-C (Cohen d = 0.47; SE = 0.347; p = 0.089) and TC (Cohen d = 0.34; SE = 0.225; p = 0.066), respectively. T'ai chi may potentially be beneficial on lipid profiles across different age groups and populations. Although there were conflicting results regarding the effect of t'ai chi on lipid profiles, the majority of studies had at least a small positive effect indicating

Effect of Tai Chi Training on Dual-Tasking Performance That Involves Stepping Down among Stroke Survivors: A Pilot Study.

PubMed

Chan, Wing-Nga; Tsang, William Wai-Nam

2017-01-01

Descending stairs demands attention and neuromuscular control, especially with dual-tasking. Studies have demonstrated that stroke often degrades a survivor's ability to descend stairs. Tai Chi has been shown to improve dual-tasking performance of healthy older adults, but no such study has been conducted in stroke survivors. This study investigated the effect of Tai Chi training on dual-tasking performance that involved stepping down and compared it with that of conventional exercise among stroke survivors. Subjects were randomized into Tai Chi ( n = 9), conventional exercise ( n = 8), and control ( n = 9) groups. Those in the former two groups received 12-week training. Assessments included auditory Stroop test, stepping down test, and dual-tasking test involving both simultaneously. They were evaluated before training (time-1), after training (time-2), and one month after training (time-3). Tai Chi group showed significant improvement in the auditory Stroop test from time-1 to time-3 and the performance was significantly better than that of the conventional exercise group in time-3. No significant effect was found in the stepping down task or dual-tasking in the control group. These results suggest a beneficial effect of Tai Chi training on cognition among stroke survivors without compromising physical task performance in dual-tasking. The effect was better than the conventional exercise group. Nevertheless, further research with a larger sample is warranted.

Ground reaction force characteristics of Tai Chi push hand.

PubMed

Chang, Yao-Ting; Chang, Jia-Hao; Huang, Chen-Fu

2014-01-01

Push Hand is an advanced training technique for the Yang-style old frame 108 forms Tai Chi Chuan. It is performed by two practitioners. To clarify how people use forces during Push Hand training, it is important to review the ground reaction force (GRF). Here, we quantify the characteristics of the GRF during Push Hand training. Kinematic data and GRF data from 10 Tai Chi Chuan practitioners (29.9 ± 7.87 years) were synchronously recorded using a three-dimensional motion analysis system (200 frames · s(-1)) and three-dimensional force plates (1000 Hz). The resultant GRF for both feet for the 0%, 50% and 100% phases of attack and defence were compared to body weight using a paired-samples t-test. The differences in the resultant GRF between the 0%, 50% and 100% phases of attack and defence were tested by one-way repeated-measures ANOVA. The significance level was set to 0.05. The total resultant GRF was almost equal to the participant's body weight in push hand. This result was consistent throughout the entire push hand process. Our results revealed that the GRF was comparable to the body weight, implying that practitioners do not push or resist their opponents during the push hand process.

Cross-Sectional Comparison of Executive Attention Function in Normally Aging Long-Term T'ai Chi, Meditation, and Aerobic Fitness Practitioners Versus Sedentary Adults

PubMed Central

Manselle, Wayne; Woollacott, Marjorie H.

2014-01-01

Abstract This cross-sectional field study documented the effect of long-term t'ai chi, meditation, or aerobic exercise training versus a sedentary lifestyle on executive function. It was predicted that long-term training in t'ai chi and meditation plus exercise would produce greater benefits to executive function than aerobic exercise. T'ai chi and meditation plus exercise include mental and physical training. Fifty-four volunteers were tested: t'ai chi (n=10); meditation+exercise (n=16); aerobic exercisers (n=16); and sedentary controls (n=12). A one-factor (group), one-covariate (age) multivariate analysis of covariance was performed. Significant main effects of group and age were found (group, 67.9%, p<0.001; age, 76.3%, p=0.001). T'ai chi and meditation practitioners but not aerobic exercisers outperformed sedentary controls on percent switch costs (p=0.001 and p=0.006, respectively), suggesting that there may be differential effects of training type on executive function. PMID:24286339

Effects of Tai Chi on health related quality of life in patients with chronic conditions: a systematic review of randomized controlled trials.

PubMed

Li, Guichen; Yuan, Hua; Zhang, Wei

2014-08-01

To determine the effects of Tai Chi practice on health related quality of life in patients with various chronic medical conditions. One of the characters of chronic illness is life-long condition with the deterioration in health related quality of life. Tai Chi has become a popular mind-body exercise and self-management strategy for patients with chronic conditions regarding its various physical and psychological effects. Eight databases (the Cochrane Library, PubMed, Medline, EBSCO, Web of science and three Chinese databases: CNKI, Wanfang data and VIP) were searched (up to December 2013) for relevant studies. Studies including participants with chronic conditions were selected. All studies were randomized controlled trials reporting the effects of Tai Chi on health related quality of life. Two independent reviewers extracted trial data and assessed risk of bias using the risk of bias tool recommended by the Cochrane Back Review Group. Of the 2021 papers which were screened, 21 studies including 1200 patients met the eligibility criteria. Most studies (18 of 21 studies) found significant improvements on health related quality of life for participants with chronic conditions in Tai Chi group. No evidence was observed to suggest that Tai Chi was more effective than other types of exercise. And objective measures were not always consistent with self-reported quality of life measures. Tai Chi appears to be safe and has positive effects on health related quality of life in patients with chronic conditions, especially for patients with disorders in Cardio-cerebrovascular and respiratory systems, and musculoskeletal system. However, as the delivery mood of Tai Chi provides multiply benefits, which part of the group provides the most benefit in improving quality of life is unclear. Due to the design limitations of previous studies, more larger and well-designed RCTs are needed to confirm the effects. And qualitative researches are warranted to explore how Tai Chi may work

Economic Evaluation of a Tai Ji Quan Intervention to Reduce Falls in People With Parkinson Disease, Oregon, 2008-2011.

PubMed

Li, Fuzhong; Harmer, Peter

2015-07-30

Exercise is effective in reducing falls in people with Parkinson disease. However, information on the cost effectiveness of this approach is lacking. We conducted a cost-effectiveness analysis of Tai Ji Quan for reducing falls among patients with mild-to-moderate Parkinson disease. We used data from a previous intervention trial to analyze resource use costs related to intervention delivery and number of falls observed during a 9-month study period. Cost effectiveness was estimated via incremental cost-effectiveness ratio (ICER) in which Tai Ji Quan was compared with 2 alternative interventions (Resistance training and Stretching) on the primary outcome of per fall prevented and the secondary outcome of per participant quality-adjusted life years (QALY) gained. We also conducted subgroup and sensitivity analyses. Tai Ji Quan was more effective than either Resistance training or Stretching; it had the lowest cost and was the most effective in improving primary and secondary outcomes. Compared with Stretching, Tai Ji Quan cost an average of $175 less for each additional fall prevented and produced a substantial improvement in QALY gained at a lower cost. Results from subgroup and sensitivity analyses showed no variation in cost-effectiveness estimates. However, sensitivity analyses demonstrated a much lower ICER ($27) when only intervention costs were considered. Tai Ji Quan represents a cost-effective strategy for optimizing spending to prevent falls and maximize health gains in people with Parkinson disease. While these results are promising, they warrant further validation.

[About da tai - abortion in old Chinese folk medicine handwritten manuscripts].

PubMed

Zheng, Jinsheng

2013-01-01

Of 881 Chinese handwritten volumes with medical texts of the 17th through mid-20th century held by Staatsbibliothek zu Berlin and Ethnologisches Museum Berlin-Dahlem, 48 volumes include prescriptions for induced abortion. A comparison shows that these records are significantly different from references to abortion in Chinese printed medical texts of pre-modern times. For example, the percentage of recipes recommended for artificial abortions in handwritten texts is significantly higher than those in printed medical books. Authors of handwritten texts used 25 terms to designate artificial abortion, with the term da tai [see text], lit.: "to strike the fetus", occurring most frequently. Its meaning is well defined, in contrast to other terms used, such as duo tai [see text], lit: "to make a fetus fall", xia tai [see text], lit. "to bring a fetus down", und duan chan [see text], lit., to interrupt birthing", which is mostly used to indicate a temporary or permanent sterilization. Pre-modern Chinese medicine has not generally abstained from inducing abortions; physicians showed a differentiating attitude. While abortions were descibed as "things a [physician with an attitude of] humaneness will not do", in case a pregnancy was seen as too risky for a woman she was offered medication to terminate this pregnancy. The commercial application of abortifacients has been recorded in China since ancient times. A request for such services has continued over time for various reasons, including so-called illegitimate pregnancies, and those by nuns, widows and prostitutes. In general, recipes to induce abortions documented in printed medical literature have mild effects and are to be ingested orally. In comparison, those recommended in handwritten texts are rather toxic. Possibly to minimize the negative side-effects of such medication, practitioners of folk medicine developed mechanical devices to perform "external", i.e., vaginal approaches.

Sitting Tai Chi Improves the Balance Control and Muscle Strength of Community-Dwelling Persons with Spinal Cord Injuries: A Pilot Study

PubMed Central

Tsang, William W. N.; Gao, Kelly L.; Chan, K. M.; Purves, Sheila; Macfarlane, Duncan J.; Fong, Shirley S. M.

2015-01-01

Objective. To investigate the effects of sitting Tai Chi on muscle strength, balance control, and quality of life (QOL) among survivors with spinal cord injuries (SCI). Methods. Eleven SCI survivors participated in the sitting Tai Chi training (90 minutes/session, 2 times/week for 12 weeks) and eight SCI survivors acted as controls. Dynamic sitting balance was evaluated using limits of stability test and a sequential weight shifting test in sitting. Handgrip strength was also tested using a hand-held dynamometer. QOL was measured using the World Health Organization's Quality of Life Scale. Results. Tai Chi practitioners achieved significant improvements in their reaction time (P = 0.042); maximum excursion (P = 0.016); and directional control (P = 0.025) in the limits of stability test after training. In the sequential weight shifting test, they significantly improved their total time to sequentially hit the 12 targets (P = 0.035). Significant improvement in handgrip strength was also found among the Tai Chi practitioners (P = 0.049). However, no significant within and between-group differences were found in the QOL outcomes (P > 0.05). Conclusions. Twelve weeks of sitting Tai Chi training could improve the dynamic sitting balance and handgrip strength, but not QOL, of the SCI survivors. PMID:25688276

Effect of a Combined Tai Chi, Resistance Training and Dietary Intervention on Cognitive Function in Obese Older Women.

PubMed

Xu, F; Delmonico, M J; Lofgren, I E; Uy, K M; Maris, S A; Quintanilla, D; Taetzsch, A G; Letendre, J; Mahler, L

2017-01-01

Cognitive decline in older adults is a major public health problem and can compromise independence and quality of life. Exercise and diet have been studied independently and have shown to be beneficial for cognitive function, however, a combined Tai Chi, resistance training, and diet intervention and its influence on cognitive function has not been undertaken. The current study used a 12-week non-randomized research design with experiment and control groups to examine the effect of a combined Tai Chi, resistance training, and diet intervention on cognitive function in 25 older obese women. Results revealed improvements in domain specific cognitive function in our sample. Baseline cognitive function was correlated with changes in dietary quality. These findings suggest that Tai Chi and resistance training combined with diet intervention might be beneficial for community-based programs aiming to improve cognitive function.

Tai Chi and Your Health: A Modern Take on an Ancient Practice

MedlinePlus

... may be geared toward college students and stress management; others may be designed for folks over age 60 with particular medical conditions. Observe several teachers and classes to find a fit for you. There are different teaching styles, levels, and ways to practice tai chi. Don’ ...

Effects of Tai Chi Exercise on Glucose Control, Neuropathy Scores, Balance, and Quality of Life in Patients with Type 2 Diabetes and Neuropathy

PubMed Central

Ahn, Sukhee

2012-01-01

Abstract Purpose The aim of this study was to determine the effects of Tai Chi exercise on glucose control, neuropathy scores, balance, and quality of life in patients with type 2 diabetes and neuropathy. Methods A pretest–posttest design with a nonequivalent control group was utilized to recruit 59 diabetic patients with neuropathy from an outpatient clinic of a university hospital. A standardized Tai Chi for diabetes program was provided, which comprised 1 hour of Tai Chi per session, twice a week for 12 weeks. Outcome variables were fasting blood glucose and glycosylated hemoglobin for glucose control, the Semmes-Weinstein 10-g monofilament examination scores and total symptom scores for neuropathy, single leg stance for balance, and the Korean version of the SF-36v2 for quality of life. Thirty-nine patients completed the posttest measures after the 12-week Tai Chi intervention, giving a 34% dropout rate. Results The mean age of the participants was 64 years, and they had been diagnosed with type 2 diabetes for more than 12 years. The status was significantly better for the participants in the Tai Chi group (n=20) than for their control (i.e., nonintervention) counterparts (n=19) in terms of total symptom scores, glucose control, balance, and quality of life. Conclusion Tai Chi improved glucose control, balance, neuropathic symptoms, and some dimensions of quality of life in diabetic patients with neuropathy. Further studies with larger samples and long-term follow-up are needed to confirm the effects of Tai Chi on the management of diabetic neuropathy, which may have an impact on fall prevention in this population. PMID:22985218

A novel comparative effectiveness study of Tai Chi versus aerobic exercise for fibromyalgia: study protocol for a randomized controlled trial.

PubMed

Wang, Chenchen; McAlindon, Timothy; Fielding, Roger A; Harvey, William F; Driban, Jeffrey B; Price, Lori Lyn; Kalish, Robert; Schmid, Anna; Scott, Tammy M; Schmid, Christopher H

2015-01-30

Fibromyalgia is a chronic musculoskeletal pain syndrome that causes substantial physical and psychological impairment and costs the US healthcare system over $25 billion annually. Current pharmacological therapies may cause serious adverse effects, are expensive, and fail to effectively improve pain and function. Finding new and effective non-pharmacological treatments for fibromyalgia patients is urgently needed. We are currently conducting the first comparative effectiveness randomized trial of Tai Chi versus aerobic exercise (a recommended component of the current standard of care) in a large fibromyalgia population. This article describes the design and conduct of this trial. A single-center, 52-week, randomized controlled trial of Tai Chi versus aerobic exercise is being conducted at an urban tertiary medical center in Boston, Massachusetts. We plan to recruit 216 patients with fibromyalgia. The study population consists of adults ≥21 years of age with fibromyalgia who meet American College of Rheumatology 1990 and 2010 diagnostic criteria. Participants are randomized to one of four Tai Chi intervention groups: 12 or 24 weeks of supervised Tai Chi held once or twice per week, or a supervised aerobic exercise control held twice per week for 24 weeks. The primary outcome is the change in Revised Fibromyalgia Impact Questionnaire total score from baseline to 24 weeks. Secondary outcomes include measures of widespread pain, symptom severity, functional performance, balance, muscle strength and power, psychological functioning, sleep quality, self-efficacy, durability effects, and health-related quality of life at 12, 24, and 52 week follow-up. This study is the first comparative effectiveness randomized trial of Tai Chi versus aerobic exercise in a large fibromyalgia population with long-term follow up. We present here a robust and well-designed trial to determine the optimal frequency and duration of a supervised Tai Chi intervention with regard to short

Structure and spatial patterns of macrobenthic community in Tai Lake, a large shallow lake, China

USGS Publications Warehouse

Di Li,; Erickson, Richard A.; Song Tang,; Xuwen Li,; Niu, Zhichun; Xia Wang,; Hongling Liu,; Hongxia Yu,

2016-01-01

Tai Lake (Chinese: Taihu), the third-largest freshwater lake in China, suffers from harmful cyanobacteria blooms that are caused by economic development and population growth near the lake. Several studies have focused on phytoplankton in Tai Lake after a drinking water crisis in 2007; however, these studies primarily focused on microcystin bioaccumulation and toxicity to individual species without examining the effects of microcystin on macrobenthic community diversity. In this study, we conducted a survey of the lake to examine the effects of microcystine and other pollutants on marcobenthic community diversity. A totally of forty-nine species of macroinvertebrates were found in Tai Lake. Limnodrilus hoffmeisteri and Corbicula fluminea were the most abundant species. Cluster-analysis and one-way analysis of similarity (ANOSIM) identified three significantly different macrobenthic communities among the sample sites. More specifically, sites in the eastern bays, where aquatic macrophytes were abundant, had the highest diversity of macrobenthic communities, which were dominated by Bellamya aeruginosa, Bellamya purificata, L. hoffmeisteri, and Alocinma longicornis. Sites in Zhushan Bay contained relatively diverse communities, mainly composed of L. hoffmeisteri, C. fluminea, L. claparederanus, R. sinicus, and Cythura sp. Sites in the western region, Meiliang Bay and Wuli Bay had the lowest diversity, mainly composed ofL. hoffmeisteri, C. fluminea, Branchiura sowerbyi, and Rhyacodrilus sinicus. In addition, the relationships between macrobenthic metrics (Shannon–Wiener, Margalef, and Pielou) and environmental variables showed that community structure and spatial patterns of macrobenthos in Tai Lake were significantly influenced by chemical oxygen demand (CODCr), biochemical oxygen demand (BOD5), lead (Pb), and microcystin-LR (L for leucine and R for arginine). Our findings provide critical information that could help managers and policymakers

Effectiveness of tai chi as a community-based falls prevention intervention: a randomized controlled trial.

PubMed

Taylor, Denise; Hale, Leigh; Schluter, Philip; Waters, Debra L; Binns, Elizabeth E; McCracken, Hamish; McPherson, Kathryn; Wolf, Steven L

2012-05-01

To compare the effectiveness of tai chi and low-level exercise in reducing falls in older adults; to determine whether mobility, balance, and lower limb strength improved and whether higher doses of tai chi resulted in greater effect. Randomized controlled trial. Eleven sites throughout New Zealand. Six hundred eighty-four community-residing older adults (mean age 74.5; 73% female) with at least one falls risk factor. Tai chi once a week (TC1) (n = 233); tai chi twice a week (TC2) (n = 220), or a low-level exercise program control group (LLE) (n = 231) for 20 wks. Number of falls was ascertained according to monthly falls calendars. Mobility (Timed-Up-and-Go Test), balance (step test), and lower limb strength (chair stand test) were assessed. The adjusted incident rate ratio (IRR) for falls was not significantly different between the TC1 and LLE groups (IRR = 1.05, 95% confidence interval (CI) = 0.83-1.33, P = .70) or between the TC2 and LLE groups (IRR = 0.88, 95% CI = 0.68-1.16, P = .37). Adjusted multilevel mixed-effects Poisson regression showed a significant reduction in logarithmic mean fall rate of -0.050 (95% CI = -0.064 to -0.037, P < .001) per month for all groups. Multilevel fixed-effects analyses indicated improvements in balance (P < .001 right and left leg) and lower limb strength (P < .001) but not mobility (P = .54) in all groups over time, with no differences between the groups (P = .37 (right leg), P = .66 (left leg), P = .21, and P = .44, respectively). There was no difference in falls rates between the groups, with falls reducing similarly (mean falls rate reduction of 58%) over the 17-month follow-up period. Strength and balance improved similarly in all groups over time. © 2012, Copyright the Authors Journal compilation © 2012, The American Geriatrics Society.

The effect of supervised Tai Chi intervention compared to a physiotherapy program on fall-related clinical outcomes: a randomized clinical trial.

PubMed

Tousignant, Michel; Corriveau, Hélène; Roy, Pierre-Michel; Desrosiers, Johanne; Dubuc, Nicole; Hébert, Réjean; Tremblay-Boudreault, Valérie; Beaudoin, Audrée-Jeanne

2012-01-01

To assess some fall-related clinical variables (balance, gait, fear of falling, functional autonomy, self-actualization and self-efficacy) that might explain the fact that supervised Tai Chi has a better impact on preventing falls compared to a conventional physiotherapy program. The participants (152 older adults over 65 who were admitted to a geriatric day hospital program) were randomly assigned to either a supervised Tai Chi group or the usual physiotherapy. The presence of the clinical variables related to falls was evaluated before the intervention (T1), immediately after (T2), and 12 months after the end of the intervention (T3). Both exercise programs significantly improved fall-related outcomes but only the Tai Chi intervention group decreased the incidence of falls. For both groups, most variables followed the same pattern, i.e. showed significant improvement with the intervention between T1 and T2, and followed by a statistically significant decrease at the T3 evaluation. However, self-efficacy was the only variable that improved solely with the Tai Chi intervention (p = 0.001). The impact of supervised Tai Chi on fall prevention can not be explained by a differential effect on balance, gait and fear of falling. It appeared to be related to an increase of general self-efficacy, a phenomenon which is not seen in the conventional physiotherapy program.

Feasibility and effectiveness of a Chen-style Tai Chi programme for stress reduction in junior secondary school students.

PubMed

Lee, Linda Y K; Chong, Yeuk Lan; Li, Ngai Yin; Li, Man Chung; Lin, Lai Na; Wong, Lee Yi; Wong, Brian Kit; Yip, Wing Ping; Hon, Cho Hang; Chung, Pui Kuen; Man, Shuk Yee

2013-04-01

Stress is common in junior secondary school students (JSSS). This study aimed to determine the feasibility and effectiveness of a Chen-style Tai Chi programme for stress reduction in JSSS. A non-equivalent pre-test/post-test control group design was adopted, and a convenience sample of 69 JSSS was recruited. The experimental group (n = 32) joined a Chen-style Tai Chi programme, which included 10 sessions of 80-minute Tai Chi training (one session per week). The control group (n = 37) proceeded with self-study. Participants' stress levels were assessed using the Perceived Stress Scale. Feasibility was determined as the percentage of participants completing and attending the programme. Effectiveness was measured as the significant difference in changes in stress levels before and after the intervention between the two groups. Results preliminarily supported that the programme was feasible for JSSS. Completion rate was 100%, and attendance rate was 90%. However, no significant difference was noted in changes in stress levels before and after the intervention between the two groups. The potential health benefits of Tai Chi could not be detected owing to the restrictions imposed by the research setting and study limitations. The present study represents initial efforts in this direction and serves as reference for future study. Copyright © 2012 John Wiley & Sons, Ltd.

Tai Chi and balance control.

PubMed

Wong, Alice M K; Lan, Ching

2008-01-01

Balance function begins to decline from middle age on, and poor balance function increases the risk of fall and injury. Suitable exercise training may improve balance function and prevent accidental falls. The coordination of visual, proprioceptive, vestibular and musculoskeletal system is important to maintain balance. Balance function can be evaluated by functional balance testing and sensory organization testing. Tai Chi Chuan (TC) is a popular conditioning exercise in the Chinese community, and recent studies substantiate that TC is effective in balance function enhancement and falls prevention. In studies utilizing functional balance testing, TC may increase the duration of one-leg standing and the distance of functional reach. In studies utilizing sensory organization testing, TC improves static and dynamic balance, especially in more challenging sensory perturbed condition. Therefore, TC may be prescribed as an alternative exercise program for elderly subjects or balance-impaired patients. Participants can choose to perform a complete set of TC or selected movements according to their needs. In conclusion, TC may improve balance function and is appropriate for implementation in the community.

Effectiveness of a tai-chi training and detraining on functional capacity, symptomatology and psychological outcomes in women with fibromyalgia.

PubMed

Romero-Zurita, Alejandro; Carbonell-Baeza, Ana; Aparicio, Virginia A; Ruiz, Jonatan R; Tercedor, Pablo; Delgado-Fernández, Manuel

2012-01-01

Background. The purpose was to analyze the effects of Tai-Chi training in women with fibromyalgia (FM). Methods. Thirty-two women with FM (mean age, 51.4 ± 6.8 years) attended to Tai-Chi intervention 3 sessions weekly for 28 weeks. The outcome measures were: tenderness, body composition, functional capacity and psychological outcomes (Fibromyalgia impact questionnaire (FIQ), Short Form Health Survey 36 (SF-36)). Results. Patients showed improvements on pain threshold, total number of tender points and algometer score (all P < 0.001). The intervention was effective on 6-min walk (P = 0.006), back scratch (P = 0.002), handgrip strength (P = 0.006), chair stand, chair sit & reach, 8 feet up & go and blind flamingo tests (all P < 0.001). Tai-Chi group improved the FIQ total score (P < 0.001) and six subscales: stiffness (P = 0.005), pain, fatigue, morning tiredness, anxiety, and depression (all P < 0.001). The intervention was also effective in six SF-36 subscales: bodily pain (P = 0.003), vitality (P = 0.018), physical functioning, physical role, general health, and mental health (all P < 0.001). Conclusions. A 28-week Tai-Chi intervention showed improvements on pain, functional capacity, symptomatology and psychological outcomes in female FM patients.

Effectiveness of a Tai-Chi Training and Detraining on Functional Capacity, Symptomatology and Psychological Outcomes in Women with Fibromyalgia

PubMed Central

Romero-Zurita, Alejandro; Carbonell-Baeza, Ana; Aparicio, Virginia A.; Ruiz, Jonatan R.; Tercedor, Pablo; Delgado-Fernández, Manuel

2012-01-01

Background. The purpose was to analyze the effects of Tai-Chi training in women with fibromyalgia (FM). Methods. Thirty-two women with FM (mean age, 51.4 ± 6.8 years) attended to Tai-Chi intervention 3 sessions weekly for 28 weeks. The outcome measures were: tenderness, body composition, functional capacity and psychological outcomes (Fibromyalgia impact questionnaire (FIQ), Short Form Health Survey 36 (SF-36)). Results. Patients showed improvements on pain threshold, total number of tender points and algometer score (all P < 0.001). The intervention was effective on 6-min walk (P = 0.006), back scratch (P = 0.002), handgrip strength (P = 0.006), chair stand, chair sit & reach, 8 feet up & go and blind flamingo tests (all P < 0.001). Tai-Chi group improved the FIQ total score (P < 0.001) and six subscales: stiffness (P = 0.005), pain, fatigue, morning tiredness, anxiety, and depression (all P < 0.001). The intervention was also effective in six SF-36 subscales: bodily pain (P = 0.003), vitality (P = 0.018), physical functioning, physical role, general health, and mental health (all P < 0.001). Conclusions. A 28-week Tai-Chi intervention showed improvements on pain, functional capacity, symptomatology and psychological outcomes in female FM patients. PMID:22649476

Tai Chi practitioners have better postural control and selective attention in stepping down with and without a concurrent auditory response task.

PubMed

Lu, Xi; Siu, Ka-Chun; Fu, Siu N; Hui-Chan, Christina W Y; Tsang, William W N

2013-08-01

To compare the performance of older experienced Tai Chi practitioners and healthy controls in dual-task versus single-task paradigms, namely stepping down with and without performing an auditory response task, a cross-sectional study was conducted in the Center for East-meets-West in Rehabilitation Sciences at The Hong Kong Polytechnic University, Hong Kong. Twenty-eight Tai Chi practitioners (73.6 ± 4.2 years) and 30 healthy control subjects (72.4 ± 6.1 years) were recruited. Participants were asked to step down from a 19-cm-high platform and maintain a single-leg stance for 10 s with and without a concurrent cognitive task. The cognitive task was an auditory Stroop test in which the participants were required to respond to different tones of voices regardless of their word meanings. Postural stability after stepping down under single- and dual-task paradigms, in terms of excursion of the subject's center of pressure (COP) and cognitive performance, was measured for comparison between the two groups. Our findings demonstrated significant between-group differences in more outcome measures during dual-task than single-task performance. Thus, the auditory Stroop test showed that Tai Chi practitioners achieved not only significantly less error rate in single-task, but also significantly faster reaction time in dual-task, when compared with healthy controls similar in age and other relevant demographics. Similarly, the stepping-down task showed that Tai Chi practitioners not only displayed significantly less COP sway area in single-task, but also significantly less COP sway path than healthy controls in dual-task. These results showed that Tai Chi practitioners achieved better postural stability after stepping down as well as better performance in auditory response task than healthy controls. The improved performance that was magnified by dual motor-cognitive task performance may point to the benefits of Tai Chi being a mind-and-body exercise.

Tai Ji Quan and global cognitive function in older adults with cognitive impairment: a pilot study.

PubMed

Li, Fuzhong; Harmer, Peter; Liu, Yu; Chou, Li-Shan

2014-01-01

This study evaluated whether Tai Ji Quan: Moving for Better Balance (TJQMBB) could improve global cognitive function in older adults with cognitive impairment. Using a nonrandomized control group pretest-posttest design, participants aged ≥65 years who scored between 20 and 25 on the Mini-Mental State Examination (MMSE) were allocated into either a 14-week TJQMBB program (n=22) or a control group (n=24). The primary outcome was MMSE as a measure of global cognitive function with secondary outcomes of 50-ft speed walk, Timed Up&Go, and Activities-Specific Balance Confidence (ABC) scale. At 14 weeks, Tai Ji Quan participants showed significant improvement on MMSE (mean=2.26, p<0.001) compared to controls (mean=0.63, p=0.08). Similarly, Tai Ji Quan participants performed significantly better compared to the controls in both physical performance and balance efficacy measures (p<0.05). Improvement in cognition as measured by MMSE was related to improved physical performance and balance efficacy. These results provide preliminary evidence of the utility of the TJQMBB program to promote cognitive function in older adults in addition to physical benefits. Copyright © 2014 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Efficacy and Safety of Tai Chi for Parkinson's Disease: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

PubMed Central

Ni, Xiaojia; Liu, Shaonan; Lu, Fuchang; Shi, Xiaogeng; Guo, Xinfeng

2014-01-01

Background and Objective In Parkinson's disease (PD), wearing off and side effects of long-term medication and complications pose challenges for neurologists. Although Tai Chi is beneficial for many illnesses, its efficacy for PD remains uncertain. The purpose of this review was to evaluate the efficacy and safety of Tai Chi for PD. Methods Randomized controlled trials (RCTs) of Tai Chi for PD were electronically searched by the end of December 2013 and identified by two independent reviewers. The tool from the Cochrane Handbook 5.1 was used to assess the risk of bias. A standard meta-analysis was performed using RevMan 5.2 software. Results Ten trials with PD of mild-to-moderate severity were included in the review, and nine trials (n = 409) were included in the meta-analysis. The risk of bias was generally high in the blinding of participants and personnel. Improvements in the Unified Parkinson's Disease Rating Scale Part III (mean difference (MD) −4.34, 95% confidence interval (CI) −6.67–−2.01), Berg Balance Scale (MD: 4.25, 95% CI: 2.83–5.66), functional reach test (MD: 3.89, 95% CI: 1.73–6.04), Timed Up and Go test (MD: −0.75, 95% CI: −1.30–−0.21), stride length (standardized MD: 0.56, 95% CI: 0.03–1.09), health-related quality of life (standardized MD: −1.10, 95% CI: −1.81–−0.39) and reduction of falls were greater after interventions with Tai Chi plus medication. Satisfaction and safety were high. Intervention with Tai Chi alone was more effective for only a few balance and mobility outcomes. Conclusions Tai Chi performed with medication resulted in promising gains in mobility and balance, and it was safe and popular among PD patients at an early stage of the disease. This provides a new evidence for PD management. More RCTs with larger sample size that carefully address blinding and prudently select outcomes are needed. PROSPERO registration number CRD42013004989. PMID:24927169

Protocol: the effect of 12 weeks of Tai Chi practice on anxiety in healthy but stressed people compared to exercise and wait-list comparison groups: a randomized controlled trial.

PubMed

Zheng, Shuai; Lal, Sara; Meier, Peter; Sibbritt, David; Zaslawski, Chris

2014-06-01

Stress is a major problem in today's fast-paced society and can lead to serious psychosomatic complications. The ancient Chinese mind-body exercise of Tai Chi may provide an alternative and self-sustaining option to pharmaceutical medication for stressed individuals to improve their coping mechanisms. The protocol of this study is designed to evaluate whether Tai Chi practice is equivalent to standard exercise and whether the Tai Chi group is superior to a wait-list control group in improving stress coping levels. This study is a 6-week, three-arm, parallel, randomized, clinical trial designed to evaluate Tai Chi practice against standard exercise and a Tai Chi group against a nonactive control group over a period of 6 weeks with a 6-week follow-up. A total of 72 healthy adult participants (aged 18-60 years) who are either Tai Chi naïve or have not practiced Tai Chi in the past 12 months will be randomized into a Tai Chi group (n = 24), an exercise group (n = 24) or a wait-list group (n = 24). The primary outcome measure will be the State Trait Anxiety Inventory with secondary outcome measures being the Perceived Stress Scale 14, heart rate variability, blood pressure, Short Form 36 and a visual analog scale. The protocol is reported using the appropriate Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) items. Copyright © 2014. Published by Elsevier B.V.

The defence technique in Tai Chi Push Hands: a case study.

PubMed

Chen, Hui-Chuan; Cheng, Kuang-You B; Liu, Yu-Jen; Chiu, Hung-Ta; Cheng, Kuang-Yu

2010-12-01

Developed from traditional Chinese martial arts, Tai Chi exercise includes different forms and interactive Push Hands but biomechanical analyses have focused on the former only. To analyse the techniques of Push Hands, an experienced master was asked to defend pushing by four opponents. Movements were videotaped and digitized using a motion analysis system. Surface electrodes were used to record the electromyographic activity of ten muscle groups. Two force plates were used to measure the ground reaction force on each foot. Inexperienced individuals performed the same procedure to serve as the control group. The results indicate that the master adopted a postural adjustment to maintain balance. A clear shift of body weight from the front to the rear foot and mediolateral displacement of the centre of gravity was observed. Low electromyographic activity was observed in the upper body muscle groups, while high electromyographic activity was observed in the right rectus femoris and very high activity in the left rectus femoris during the defence. All inexperienced participants lost their balance in resisting pushing. It is concluded that the Tai Chi defensive technique includes a subtle postural adjustment that slightly changes the pushing force direction, and allows the rear leg to resist the incoming force.

Evaluating Exercise Prescription and Instructional Methods Used in Tai Chi Studies Aimed at Improving Balance in Older Adults: A Systematic Review.

PubMed

Wu, Yin; MacDonald, Hayley V; Pescatello, Linda S

2016-10-01

To develop an evaluation instrument to determine to what extent Tai Chi interventions aimed at improving the balance of older adults disclosed their exercise prescription (Ex R x ) and instructional methods and met best-practice exercise recommendations for balance improvement. Review. PubMed, Scopus, and CINAHL databases were searched from their inception until August 22, 2014. Adults aged 60 and older without debilitating disease. Three electronic databases were searched to identify randomized controlled trials (RCTs) of Tai Chi interventions aimed at improving balance in older adults without severe debilitating diseases. Three Ex R x (frequency, time, intervention length) and 10 instructional (e.g., style, number of forms) methods of the included RCTs were evaluated. Twenty-seven interventions were identified from 26 RCTs. On average, Tai Chi was performed for a mean 56.5 ± 14.4 minutes per session for 2.8 ± 1.4 sessions per week for 19.7 ± 12.7 weeks. Most interventions reported all three Ex R x methods items, with a mean reporting rate of 92.6 ± 19.2%. For the 10 instructional methods items, the mean reporting rate was 41.1 ± 18.0%, significantly lower than for the Ex R x methods items (P < .001). Fewer than half of the interventions reported unsupervised practice (15%), progression (22%), or the use of breathing (30%) and relaxation (15%) techniques. The instructional methods items most important for targeting Tai Chi practice to improve balance were not routinely disclosed, with only 15% reporting names of forms and 52% reporting movement principles. Most Tai Chi interventions disclosed their Ex R x methods yet routinely failed to report instructional methods. To increase the effectiveness of Tai Chi to improve balance in older adults, future RCTs should disclose their Ex R x and instructional methods, especially methods that target balance. © 2016, Copyright the Authors Journal compilation © 2016, The American Geriatrics Society.

59. The right hand portion of the Wah Chong Tai ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

59. The right hand portion of the Wah Chong Tai Co. was built by a Chinese immigrant in the late 1890s as a noodle factory and store for Chinese imported goods. The left portion was constructed in 1909 and a noodle parlor was opened on the upper story. This building has a distinctive oriental design around the windows. Both buildings are substantially intact, and retain basement level storefronts. - Butte Historic District, Bounded by Copper, Arizona, Mercury & Continental Streets, Butte, Silver Bow County, MT

Effects of Tai Chi-based cardiac rehabilitation on aerobic endurance, psychosocial well-being, and cardiovascular risk reduction among patients with coronary heart disease: A systematic review and meta-analysis.

PubMed

Liu, Ting; Chan, Aileen Wk; Liu, Yun Hong; Taylor-Piliae, Ruth E

2018-04-01

Tai Chi is an attractive exercise to improve cardiovascular health. This review aimed to synthesize articles written both in Chinese and in English to evaluate the effects of Tai Chi-based cardiac rehabilitation on aerobic endurance, psychosocial well-being and cardiovascular diseases risk reduction for coronary heart diseases patients. PRISMA guidelines were used to search major health databases to identify randomized controlled trials or non-randomized controlled clinical trials that evaluated Tai Chi intervention compared with active or non-active control groups in coronary heart disease patients. When suitable, data were pooled using a random-effects meta-analysis model. Thirteen studies met the inclusion criteria. Tai Chi groups showed a large and significant improvement in aerobic endurance compared with both active and non-active control interventions (standard mean difference (SMD) 1.12; 95% confidence interval (CI): 0.58-1.66; p <0.001). Tai Chi groups also showed a significantly lower level of anxiety (SMD=9.28; CI: 17.46-1.10; p=0.03) and depression (SMD=9.42; CI: 13.59-5.26; p <0.001), and significantly better quality of life (SMD=0.73; 95% CI: 0.39-1.08; p <0.001) compared with non-active control groups. Significant effects of Tai Chi have been found in improving aerobic endurance and psychosocial well-being among coronary heart disease patients. Tai Chi could be a cost-effective and safe exercise option in cardiac rehabilitation. However, the effect of Tai Chi on cardiovascular disease risk reduction has not been amply investigated among coronary heart disease patients. Caution is also warranted in view of a small number of studies for this meta-analysis and potential heterogeneity in differences in the varied designs of Tai Chi intervention.

Knee osteoarthritis pain in the elderly can be reduced by massage therapy, yoga and tai chi: A review.

PubMed

Field, Tiffany

2016-02-01

This is a review of recently published research, both empirical studies and meta-analyses, on the effects of complementary therapies including massage therapy, yoga and tai chi on pain associated with knee osteoarthritis in the elderly. The massage therapy protocols have been effective in not only reducing pain but also in increasing range of motion, specifically when moderate pressure massage was used and when both the quadriceps and hamstrings were massaged. The yoga studies typically measured pain by the WOMAC. Most of those studies showed a clinically significant reduction in pain, especially the research that focused on poses (e.g. the Iyengar studies) as opposed to those that had integrated protocols (poses, breathing and meditation exercises). The tai chi studies also assessed pain by self-report on the WOMAC and showed significant reductions in pain. The tai chi studies were difficult to compare because of their highly variable protocols in terms of the frequency and duration of treatment. Larger, randomized control trials are needed on each of these therapies using more standardized protocols and more objective variables in addition to the self-reported WOMAC pain scale, for example, range-of-motion and observed range-of-motion pain. In addition, treatment comparison studies should be conducted so, for example, if the lower-cost yoga and tai chi were as effective as massage therapy, they might be used in combination with or as supplemental to massage therapy. Nonetheless, these therapies are at least reducing pain in knee osteoarthritis and they do not seem to have side effects. Copyright © 2016 Elsevier Ltd. All rights reserved.

The influence of tai chi and yoga on balance and falls in a residential care setting: A randomised controlled trial.

PubMed

Saravanakumar, Padmapriya; Higgins, Isabel Johanna; van der Riet, Pamela Jane; Marquez, Jodie; Sibbritt, David

2014-01-01

Abstract Falls amongst older people is a global public health concern. Whilst falling is not a typical feature of ageing, older people are more likely to fall. Fall injuries amongst older people are a leading cause of death and disability. Many older people do not do regular exercise so that they lose muscle tone, strength, and flexibility which affect balance and predispose them to falls. The management of falls in residential care settings is a major concern with strategies for prevention and monitoring a focus in this setting. Yoga and tai chi have shown potential to improve balance and prevent falls in older adults. They also have potential to improve pain and quality of life. The aim of this study was to determine the feasibility of conducting a three-arm randomised controlled trial (RCT) with frail older people in a residential care setting to test the hypothesis that a 14-week modified tai chi or yoga programme is more effective than usual care activity in improving balance function, quality of life, pain experience and in reducing number of falls. There were no statistically significant differences between the three groups in the occurrence of falls. Yoga demonstrated a slight decrease in fall incidence; quality of life improved for the tai chi group. Only the yoga group experienced a reduction in average pain scores though not statistically significant. The findings of the study suggest it is possible to safely implement modified yoga and tai chi in a residential care setting and evaluate this using RCT design. They show positive changes to balance, pain and quality of life and a high level of interest through attendance amongst the older participants. The results support offering tai chi and yoga to older people who are frail and dependent with physical and cognitive limitations.

Genetic structure of the Mon-Khmer speaking groups and their affinity to the neighbouring Tai populations in Northern Thailand

PubMed Central

2011-01-01

Background The Mon-Khmer speaking peoples inhabited northern Thailand before the arrival of the Tai speaking people from southern China in the thirteenth century A.D. Historical and anthropological evidence suggests a close relationship between the Mon-Khmer groups and the present day majority northern Thai groups. In this study, mitochondrial and Y-chromosomal DNA polymorphisms in more than 800 volunteers from eight Mon-Khmer and ten Tai speaking populations were investigated to estimate the degree of genetic divergence between these major linguistic groups and their internal structure. Results A large fraction of genetic variation is observed within populations (about 80% and 90% for mtDNA and the Y-chromosome, respectively). The genetic divergence between populations is much higher in Mon-Khmer than in Tai speaking groups, especially at the paternally inherited markers. The two major linguistic groups are genetically distinct, but only for a marginal fraction (1 to 2%) of the total genetic variation. Genetic distances between populations correlate with their linguistic differences, whereas the geographic distance does not explain the genetic divergence pattern. Conclusions The Mon-Khmer speaking populations in northern Thailand exhibited the genetic divergence among each other and also when compared to Tai speaking peoples. The different drift effects and the post-marital residence patterns between the two linguistic groups are the explanation for a small but significant fraction of the genetic variation pattern within and between them. PMID:21672265

Genetic structure of the Mon-Khmer speaking groups and their affinity to the neighbouring Tai populations in Northern Thailand.

PubMed

Kutanan, Wibhu; Kampuansai, Jatupol; Fuselli, Silvia; Nakbunlung, Supaporn; Seielstad, Mark; Bertorelle, Giorgio; Kangwanpong, Daoroong

2011-06-15

The Mon-Khmer speaking peoples inhabited northern Thailand before the arrival of the Tai speaking people from southern China in the thirteenth century A.D. Historical and anthropological evidence suggests a close relationship between the Mon-Khmer groups and the present day majority northern Thai groups. In this study, mitochondrial and Y-chromosomal DNA polymorphisms in more than 800 volunteers from eight Mon-Khmer and ten Tai speaking populations were investigated to estimate the degree of genetic divergence between these major linguistic groups and their internal structure. A large fraction of genetic variation is observed within populations (about 80% and 90% for mtDNA and the Y-chromosome, respectively). The genetic divergence between populations is much higher in Mon-Khmer than in Tai speaking groups, especially at the paternally inherited markers. The two major linguistic groups are genetically distinct, but only for a marginal fraction (1 to 2%) of the total genetic variation. Genetic distances between populations correlate with their linguistic differences, whereas the geographic distance does not explain the genetic divergence pattern. The Mon-Khmer speaking populations in northern Thailand exhibited the genetic divergence among each other and also when compared to Tai speaking peoples. The different drift effects and the post-marital residence patterns between the two linguistic groups are the explanation for a small but significant fraction of the genetic variation pattern within and between them. © 2011 Kutanan et al; licensee BioMed Central Ltd.

Dietary risk ranking for residual antibiotics in cultured aquatic products around Tai Lake, China.

PubMed

Song, Chao; Li, Le; Zhang, Cong; Qiu, Liping; Fan, Limin; Wu, Wei; Meng, Shunlong; Hu, Gengdong; Chen, Jiazhang; Liu, Ying; Mao, Aimin

2017-10-01

Antibiotics are widely used in aquaculture and therefore may be present as a dietary risk in cultured aquatic products. Using the Tai Lake Basin as a study area, we assessed the presence of 15 antibiotics in 5 widely cultured aquatic species using a newly developed dietary risk ranking approach. By assigning scores to each factor involved in the ranking matrices, the scores of dietary risks per antibiotic and per aquatic species were calculated. The results indicated that fluoroquinolone antibiotics posed the highest dietary risk in all aquatic species. Then, the total scores per aquatic species were summed by all 15 antibiotic scores of antibiotics, it was found that Crab (Eriocheir sinensis) had the highest dietary risks. Finally, the most concerned antibiotic category and aquatic species were selected. This study highlighted the importance of dietary risk ranking in the production and consumption of cultured aquatic products around Tai Lake. Copyright © 2017 Elsevier Inc. All rights reserved.

The Impact of Combined Music and Tai Chi on Depressive Symptoms Among Community-Dwelling Older Persons: A Cluster Randomized Controlled Trial.

PubMed

Liao, S J; Tan, M P; Chong, M C; Chua, Y P

2018-05-01

The effectiveness of pharmacological treatment may be limited in older persons. Several studies using Tai Chi or music therapy separately confirmed positive effects in the reduction of depressive symptoms. We conducted a cluster randomized controlled trial to evaluate the possible synergistic effect of combined music and Tai Chi on depressive symptoms. One hundred and seven older adults with mild to moderate depressive symptoms were recruited from Ya'an city. Fifty-five participants were cluster randomized to combined music and Tai Chi group for three months, while the other fifty-two individuals were randomized to the control group that entailed routine health education delivered monthly by community nurses. The primary outcome of depressive symptoms was measured with the Geriatric Depression Scale (GDS) at baseline and monthly for three months. At three-month follow-up, a statistically significant improvement in depressive symptoms was found in the intervention group compared with control group (F(3,315) = 69.661, P < 0.001). Following adjustments for socio-demographic data, the true effect of intervention on depressive symptoms was significant (F = 41.725, P < 0.01, η p 2 = 0.574). Combined music and Tai Chi reduced depressive symptoms among community-dwelling older persons. This represents an economically viable solution to the management of depression in highly populous developing nations.

Efficacy of supervised Tai Chi exercises versus conventional physical therapy exercises in fall prevention for frail older adults: a randomized controlled trial.

PubMed

Tousignant, Michel; Corriveau, Hélène; Roy, Pierre-Michel; Desrosiers, Johanne; Dubuc, Nicole; Hébert, Réjean

2013-08-01

To compare the effectiveness of supervised Tai Chi exercises versus the conventional physical therapy exercises in a personalized rehabilitation program in terms of the incidence and severity of falls in a frail older population. The participants were frail older adults living in the community, admitted to the day hospital program in Sherbrooke, Quebec, Canada (n = 152). They were randomized to receive a 15-week intervention, either by supervised Tai Chi exercises (n = 76) or conventional physical therapy (n = 76). Fall incidence and severity were assessed using both the calendar technique and phone interviews once a month during 12 months following the end of the intervention. Other variables were collected at baseline to compare the two groups: age, comorbidity, balance, sensory interaction on balance, and self-rated health. Both interventions demonstrated a protective effect on falls but Tai Chi showed a greater one (RR = 0.74; 95% CI = 0.56-0.98) as compared to conventional physical therapy exercises. Supervised Tai Chi exercises as part of a rehabilitation program seem to be a more effective alternative to the conventional physical therapy exercises for this specific population.

Effect of Tai Ji Quan training on self-reported sleep quality in elderly Chinese women with knee osteoarthritis: a randomized controlled trail.

PubMed

Lü, Jiaojiao; Huang, Lingyan; Wu, Xie; Fu, Weijie; Liu, Yu

2017-05-01

The purpose of this study was to explore the effects of a 24-week Tai Ji Quan training program on sleep quality, quality of life, and physical performance among elderly Chinese women with knee osteoarthritis (OA). A 24-week randomized, controlled trial of 46 elderly women with knee OA. Participants were randomly assigned to either a Tai Ji Quan group (n = 23) or a control group (n = 23). Participants in the Tai Ji Quan group completed training sessions three times per week, while those in the control group had bi-weekly educational classes. The primary outcome was total score of the Pittsburgh Sleep Quality of Index (PSQI). Secondary outcomes were: seven subscales of the PSQI; sleep latency; total sleep time; sleep efficiency; physical component summary (PCS) and mental component summary (MCS) of the 36-item Short Form Health Survey (SF-36); Berg Balance Scale (BBS); and Timed Up and Go (TUG). Compared with the control group, participants in the Tai Ji Quan group had significantly improved primary outcome (global PSQI score, p = 0.006) and secondary outcomes, including three PSQI sub-scores (sleep latency, p = 0.031; sleep duration, p = 0.043; daytime dysfunction, p = 0.007), total sleep time (p = 0.033), and SF-36 PCS (p = 0.006). The Tai Ji Quan group also had significant improvements compared with baseline in three PSQI sub-scores (sleep latency, p = 0.031; habitual sleep efficiency, p = 0.049; sleep disturbance, p = 0.016), sleep latency (p = 0.003), BBS (p = 0.001), and TUG (p = 0.006). Tai Ji Quan training is an effective treatment approach to improve sleep quality and quality of life in elderly Chinese women with knee OA. Chinese Clinical Trial Registry (June 16, 2013): ChiCTR-TRC-13003264. Copyright © 2017 Elsevier B.V. All rights reserved.

Design and methods of the Gentle Cardiac Rehabilitation Study – A behavioral study of tai chi exercise for patients not attending cardiac rehabilitation

PubMed Central

Salmoirago-Blotcher, Elena; Wayne, Peter; Bock, Beth C; Dunsiger, Shira; Wu, Wen-Chih; Stabile, Loren; Yeh, Gloria

2015-01-01

Introduction Cardiac rehabilitation (CR) programs reduce overall and cardiovascular mortality in patients with a history of acute coronary events or revascularization procedures, but only 30 % of patients enroll in CR and attrition rates reach up to 60 %. Tai chi, a mind-body practice based on light/moderate aerobic exercise accompanied by meditative components could be a possible exercise option for patients who do not attend CR. Methods/Design Sixty patients will be randomized to a “LITE ” condition (one tai chi session twice weekly for 12 weeks) or to a “PLUS” condition (one tai chi session 3 times weekly for 12 weeks, followed by maintenance classes 1–2 times weekly for an additional 12 weeks). Measurements will be conducted at baseline, 3-, 6-, and 9 months after enrollment. The primary outcome is to determine the feasibility, acceptability and safety of each dose. Secondary outcomes include estimates of effect size of each dose on accelerometry-assessed physical activity; the proportion of patients meeting current recommendations for physical activity; and measures of fitness, quality of life, body weight, and sleep. In addition, we will collect exploratory information on possible mediators (exercise self-efficacy, perceived social support, resilience, mindfulness, and depression). Conclusions Findings from this pilot study will provide preliminary indications about the usefulness of tai chi as an exercise option for patients not attending traditional CR programs. Results will also shed light on the possible mechanisms by which tai chi practice may improve overall physical activity among patients with atherosclerotic coronary heart disease. PMID:26115880

The effects of Tai-Chi in conjunction with thera-band resistance exercise on functional fitness and muscle strength among community-based older people.

PubMed

Lin, Shu-Fen; Sung, Huei-Chuan; Li, Tzai-Li; Hsieh, Tsung-Cheng; Lan, Hsiao-Chin; Perng, Shoa-Jen; Smith, Graeme D

2015-05-01

The aim of this study was to investigate the effects of Tai-Chi in conjunction with thera-band resistance exercise on functional fitness and muscle strength in community-based older people. Tai-Chi is known to improve functional fitness in older people. Tai-Chi is usually performed with free hands without resistance training and usually focuses on training lower limbs. To date, no study has examined the use of Tai-Chi in conjunction with thera-band resistance exercise in this population. Cluster randomised trial design. Older people at six senior day care centres in Taiwan were assigned to thera-band resistance exercise or control group using a cluster randomisation. The thera-band resistance exercise group (n = 48) received sixty minute thera-band resistance exercise twice weekly for a period of 16 weeks. The control group (n = 47) underwent routine activities in the day care centre, receiving no Tai-Chi or resistance exercise. After receiving the thera-band resistance exercise, intervention participants displayed a significant increase in muscle strength of upper and lower extremities. Significant improvements were recorded on most measures of the Senior Fitness Test, with the exception of the chair-stand and back-scratch test. Thera-band resistance exercise has the potential to improve functional fitness and muscle strength in community-based older people. Thera-band resistance exercise potentially offers a safe and appropriate form of physical activity that nursing staff can easily incorporate into the daily routine of older people in day care centres, potentially improving functional performance and muscle strength. © 2015 John Wiley & Sons Ltd.

Adoption of a Tai Chi Intervention, Tai Ji Quan: Moving for Better Balance, for Fall Prevention by Rural Faith-Based Organizations, 2013-2014.

PubMed

Jones, Dina L; Starcher, Rachael W; Eicher, Jennifer L; Wilcox, Sara

2016-07-14

Translating evidence-based, community-delivered, fall-prevention exercise programs into new settings is a public health priority. Older adults (aged ≥65 y) are at high risk for falls. We conducted a community engagement project in West Virginia to evaluate the adoption of a tai chi exercise program, Tai Ji Quan: Moving for Better Balance, by rural faith-based organizations (FBOs) and exercise instructors by recruiting 20 FBOs and 20 or more exercise instructors and by obtaining input from key stakeholders (representatives of FBOs, community representatives, exercise instructors) regarding potential barriers and facilitators to program adoption. We used both multistage, purposeful random sampling and snowball sampling to recruit FBOs and exercise instructors in 7 West Virginia counties. Two forums were held with stakeholders to identify barriers and facilitators to program adoption. We calculated separate adoption rates for organizations and exercise instructors. It took up to 3 months to recruit each FBO with an adoption rate of 94%. We made 289 telephone calls, sent 193 emails and 215 letters, distributed brochures and flyers to 69 FBOs, held 118 meetings, and made 20 trips over a period of 31 days (8,933 miles traveled). Nineteen of 22 trained exercise instructors started classes, an instructor adoption rate of 86%. Key issues regarding adoption were the age requirement for participants, trust, education, and competing priorities. Although we had recruitment challenges, our adoption rates were similar to or higher than those reported in other studies, and the objectives of the community engagement project were met. Clustering the FBOs and having them located closer geographically to our location may have reduced our resource use, and using a recruitment coordinator from the local community may have enabled us to gain the trust of congregants and clergy support.

[Study on the first translated obstetrics book Tai chan ju yao (Essentials in Obstetrics)].

PubMed

Wu, M

2018-01-28

In 1893, Wan Tsun-mo translated and published Tai chan ju yao ( Essentials in Obstetrics ), the first monograph of western obstetrics in modern China, symbolizing the independence of obstetrics from such maternal and child books as Fu ying xin shuo and Fu ke jing yun tu shuo , which occupies an important position in the history of the development of modern Chinese obstetrics. The book introduced anatomy, physiology, pathology, embryology, diagnostics, surgery, pharmacology and other knowledge of obstetrics in a catechismal form, and had a detailed discussion of such advanced obstetrical technologies as antiseptic, anesthesia, forceps and cesarean section for the first time.Judging from the content and translation of Tai chan ju yao , this book has already possessed the basic knowledge system of modern obstetrics, though the translation appeared to be somewhat jerky and not elegant and the terminology needing to be further improved, it was not only used as an important medium for the introduction of obstetrical knowledge, but also of great clinical value.However, its influence was so weak that later researchers seldom mentioned this book.

Effects of T'ai Chi on Serotonin, Nicotine Dependency, Depression, and Anger in Hospitalized Alcohol-Dependent Patients.

PubMed

Oh, Chung-Uk; Kim, Nam-Cho

2016-12-01

The aim of this study was to investigate the effects of t'ai chi on blood serotonin levels, nicotine dependence, depression, and anger in hospitalized alcohol-dependent patients. This study followed an experimental and nonequivalent control group in a non-synchronized design. It was performed in a hospital located in Young Ju city, Korea, from April to August 2013. Thirty-eight patients who were hospitalized with alcohol dependence were included. They were randomly divided into an experimental and a control group, with 19 patients in each group. Patients in the experimental group practiced the 24-posture yang style t'ai chi for 50 min three times per week for 8 weeks as part of the routine hospital rehabilitation program, and those in the control group followed only the routine hospital rehabilitation program. The effect of treatment was measured using blood serotonin levels and a questionnaire on nicotine dependence, depression, and anger. Both measurements were performed before and after 8 weeks of intervention. Data were analyzed using the t-test, chi-square test, and paired t-tests. The experimental group showed a significantly increased blood serotonin level (p = 0.001) and significantly reduced nicotine dependence, depression, and anger (p = 0.001) than the control group did after 8 weeks of treatment. T'ai chi was shown to be an effective nursing intervention in hospitalized alcohol-dependent patients.

Tai Chi and Kung-Fu practice maintains physical performance but not vascular health in young versus old participants.

PubMed

McAnulty, Steven; McAnulty, Lisa; Collier, Scott; Souza-Junior, Tacito P; McBride, Jeffrey

2016-01-01

Kung-Fu and Tai Chi along with other martial arts are gaining popularity but studies examining the benefits of martial arts on physical fitness, vascular health, nutrition, and psychological wellness are limited. Aging is associated with declines in these health components. The objectives of this study were to examine whether Tai Chi and Kung-Fu training would maintain physical fitness, vascular health, and psychological wellness components on older versus younger practitioners. Seventeen subjects were recruited and divided into Young (age <40 years, n=9) and Old (age 40 years and above, n=8). Participants reported twice for health screens, vascular and nutrition assessment, and fitness tests. Mean differences were compared between groups for all tests using Student's t-tests. Age, months of practice, systolic blood pressure, and cardiovascular augmentation index were significantly greater in Old versus Young (p=0.001, p=0.007, p=0.049, and p=0.011, respectively). Psychologically, old practitioners experienced greater sleep interference (p=0.035) and overall pain (p=0.036). No other differences existed for any variable. Our study indicates that the practice of Tai Chi and Kung-Fu maintains physical fitness in older compared to younger practitioners. However, age associated changes in cardiovascular stiffness, systolic blood pressure, and pain were not prevented.

Does Tai Chi improve psychological well-being and quality of life in patients with cardiovascular disease and/or cardiovascular risk factors? A systematic review protocol.

PubMed

Yang, Guoyan; Li, Wenyuan; Cao, Huijuan; Klupp, Nerida; Liu, Jianping; Bensoussan, Alan; Kiat, Hosen; Chang, Dennis

2017-08-18

Cardiovascular disease (CVD) is a leading cause of morbidity and mortality worldwide. Psychological risk factors such as stress, anxiety and depression are known to play a significant and independent role in the development and progression of CVD and its risk factors. Tai Chi has been reported to be potentially effective for health and well-being. It is of value to assess the effectiveness and safety of Tai Chi on psychological well-being and quality of life in people with CVD and/or cardiovascular risk factors. We will include all relevant randomised controlled trials on Tai Chi for stress, anxiety, depression, psychological well-being and quality of life in people with CVD and cardiovascular risk factors. Literature searching will be conducted until 31 December 2016 from major English and Chinese databases. Two authors will conduct data selection and extraction independently. Quality assessment will be conducted using the risk of bias tool recommended by the Cochrane Collaboration. We will conduct data analysis using Cochrane's RevMan software. Forest plots and summary of findings tables will illustrate the results from a meta-analysis if sufficient studies are identified. Ethics approval is not required as this study will not involve patients. The results of this study will be submitted to a peer-reviewed journal for publication, to inform both clinical practice and further research on Tai Chi and CVDs. This review will summarise the evidence on Tai Chi for psychological well-being and quality of life in people with CVD and their risk factors. We anticipate that the results of this review would be useful for healthcare professionals and researchers on Tai Chi and CVDs. International Prospective Register for Systematic Reviews (PROSPERO) number CRD42016042905. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Investigation of new particle formation at the summit of Mt. Tai, China

NASA Astrophysics Data System (ADS)

Lv, Ganglin; Sui, Xiao; Chen, Jianmin; Jayaratne, Rohan; Mellouki, Abdelwahid

2018-02-01

To date, few comprehensive field observations of new particle formation (NPF) have been carried out at mountaintop sites in China. In this study, simultaneous measurements of particle size distribution, trace gases, meteorological parameters, and mass concentration and chemical composition of PM2.5 were performed at the summit of Mt. Tai (1534 m a.s.l.) from 25 July to 24 August 2014 (Phase I), 21 September to 9 December 2014 (Phase II), and 16 June to 7 August 2015 (Phase III) to investigate characteristics and favorable conditions of NPF in a relatively clean mountaintop environment. The NPF events were identified based on particle size distribution measured by the neutral cluster and air ion spectrometer (NAIS), and 66 such events were observed during a period of 164 days - corresponding to an occurrence frequency of 40 %. The formation rates of 3 nm particles (J3) and growth rates were in the ranges of 0.82-25.04 cm-3 s-1 and 0.58-7.76 nm h-1, respectively. On average, the condensation sink (CS), O3 concentration, air temperature, and relative humidity were lower, whereas the SO2 concentration was higher on NPF days than that on non-NPF days. The CS on Mt. Tai was at a low level and lower CS was critical for NPF. NPF events were common when wind came from the east-southeast and west-southwest, which was probably associated with relatively lower CS in the east-southeast and higher SO2 concentration in the west-southwest. O3 was not a governing factor for NPF in this study, and a high level of NOx concentration might be responsible for the decreased O3 concentration on NPF days. Three categories of backward trajectories were classified, among which the continental air mass was the majority. The continental air mass passing through more polluted areas (denoted as Type I) favored NPF because of enhanced SO2 concentration and potential ammonia with it. An in-depth analysis of SO2 indicated that sulfuric acid was a dominant precursor on Mt. Tai; meanwhile, biogenic

Evaluation of Tai Chi Yunshou exercises on community-based stroke patients with balance dysfunction: a study protocol of a cluster randomized controlled trial.

PubMed

Tao, Jing; Rao, Ting; Lin, Lili; Liu, Wei; Wu, Zhenkai; Zheng, Guohua; Su, Yusheng; Huang, Jia; Lin, Zhengkun; Wu, Jinsong; Fang, Yunhua; Chen, Lidian

2015-02-25

Balance dysfunction after stroke limits patients' general function and participation in daily life. Previous researches have suggested that Tai Chi exercise could offer a positive improvement in older individuals' balance function and reduce the risk of falls. But convincing evidence for the effectiveness of enhancing balance function after stroke with Tai Chi exercise is still inadequate. Considering the difficulties for stroke patients to complete the whole exercise, the current trial evaluates the benefit of Tai Chi Yunshou exercise for patients with balance dysfunction after stroke through a cluster randomization, parallel-controlled design. A single-blind, cluster-randomized, parallel-controlled trial will be conducted. A total of 10 community health centers (5 per arm) will be selected and randomly allocated into Tai Chi Yunshou exercise group or balance rehabilitation training group. Each community health centers will be asked to enroll 25 eligible patients into the trial. 60 minutes per each session, 1 session per day, 5 times per week and the total training round is 12 weeks. Primary and secondary outcomes will be measured at baseline and 4-weeks, 8-weeks, 12-weeks, 6-week follow-up, 12-week follow-up after randomization. Safety and economic evaluation will also be assessed. This protocol aims to evaluate the effectiveness of Tai Chi Yunshou exercise for the balance function of patients after stroke. If the outcome is positive, this project will provide an appropriate and economic balance rehabilitation technology for community-based stroke patients. Chinese Clinical Trial Registry: ChiCTR-TRC-13003641. Registration date: 22 August, 2013 http://www.chictr.org/usercenter/project/listbycreater.aspx .

Oxygen potentials in Ni + NiO and Ni + Cr2O3 + NiCr2O4 systems

NASA Astrophysics Data System (ADS)

Kale, G. M.; Fray, D. J.

1994-06-01

The chemical potential of O for the coexistence of Ni + NiO and Ni + Cr2O3 + NiCr2O4 equilibria has been measured employing solid-state galvanic cells, (+) Pt, Cu + Cu2O // (Y2O3)ZrO2 // Ni + NiO, Pt (-) and (+) Pt, Ni + NiO // (Y2O3)ZrO2 // Ni + Cr2O3 + NiCr2O4, Pt (-) in the temperature range of 800 to 1300 K and 1100 to 1460 K, respectively. The electromotive force (emf) of both the cells was reversible, reproducible on thermal cycling, and varied linearly with temperature. For the coexistence of the two-phase mixture of Ni + NiO, δΜO 2(Ni + NiO) = -470,768 + 171.77T (±20) J mol-1 (800 ≤ T ≤ 1300 K) and for the coexistence of Ni + Cr2O3 + NiCr2O4, δΜO 2(Ni + Cr2O3 + NiCr2O4) = -523,190 + 191.07T (±100) J mol-1 (1100≤ T≤ 1460 K) The “third-law” analysis of the present results for Ni + NiO gives the value of ‡H{298/o} = -239.8 (±0.05) kJ mol-1, which is independent of temperature, for the formation of one mole of NiO from its elements. This is in excellent agreement with the calorimetric enthalpy of formation of NiO reported in the literature.

Effect of green tea and Tai Chi on bone health in postmenopausal osteopenic women: a 6-month randomized placebo-controlled trial.

PubMed

Shen, C-L; Chyu, M-C; Yeh, J K; Zhang, Y; Pence, B C; Felton, C K; Brismée, J-M; Arjmandi, B H; Doctolero, S; Wang, J-S

2012-05-01

Postmenopausal women with osteopenia received green tea polyphenols (GTP) supplement and/or Tai Chi exercise for 6 months. Bone turnover biomarkers, calcium metabolism, and muscle strength were measured. This study showed that GTP supplementation and Tai Chi exercise increased bone formation biomarkers and improved bone turnover rate. Tai Chi exercise increased serum parathyroid hormone. GTP supplementation, Tai Chi exercise, and the combination of the two all improved muscle strength in postmenopausal women with osteopenia. This study evaluated the effect of GTP supplementation and Tai Chi (TC) exercise on serum markers of bone turnover (bone-specific alkaline phosphatase, BAP, and tartrate-resistant acid phosphatase, TRAP), calcium metabolism, and muscle strength in postmenopausal osteopenic women. One hundred and seventy-one postmenopausal osteopenic women were randomly assigned to four groups: (1) placebo (500 mg starch/day), (2) GTP (500 mg GTP/day), (3) placebo + TC (placebo plus TC training at 60 min/session, three sessions/week), and (4) GTP + TC (GTP plus TC training). Overnight fasting blood and urine samples were collected at baseline, 1, 3, and 6 months for biomarker analyses. Muscle strength was evaluated at baseline, 3, and 6 months. One hundred and fifty subjects completed the 6-month study. Significant increases in BAP level due to GTP intake (at 1 month) and TC (at 3 months) were observed. Significant increases in the change of BAP/TRAP ratio due to GTP (at 3 months) and TC (at 6 months) were also observed. Significant main effect of TC on the elevation in serum parathyroid hormone level was observed at 1 and 3 months. At 6 months, muscle strength significantly improved due to GTP, TC, and GTP + TC interventions. Neither GTP nor TC affected serum TRAP, serum and urinary calcium, and inorganic phosphate. In summary, GTP supplementation and TC exercise increased BAP and improved BAP/TRAP ratio. TC exercise increased serum parathyroid hormone. GTP

An Application of Project-Based Learning on the Development of Young Local Tour Guides on Tai Phuan's Culture and Tourist Attractions in Sisatchanalai District, Sukhothai Province

ERIC Educational Resources Information Center

Kerdpol, Sakon

2016-01-01

This paper presents an investigation of a research entitled, " An Application of Project-based Learning on the Development of Young Local Tour Guides on Tai Phuan's Culture and Tourist Attractions in Sisatchanalai District, Sukhothai Province. It was intended to develop young local tour guides on Tai Phuan's culture and tourist attractions in…

Preliminary findings of a 4-month Tai Chi intervention on tenderness, functional capacity, symptomatology, and quality of life in men with fibromyalgia.

PubMed

Carbonell-Baeza, Ana; Romero, Alejandro; Aparicio, Virginia A; Ortega, Francisco B; Tercedor, Pablo; Delgado-Fernández, Manuel; Ruiz, Jonatan R

2011-09-01

The study aimed to determine the effects of a 4-month Tai Chi intervention on tenderness, functional capacity, symptomatology, and quality of life in men with fibromyalgia. The effect of a 3-month detraining period was also analyzed. Six men with fibromyalgia (age 52.3 ± 9.3 years) followed a 4-month Tai Chi intervention. The outcome variables were tenderness, functional capacity (30-second chair stand, handgrip strength, chair sit and reach, back scratch, blind flamingo, 8 feet up and go, and 6-minute walk tests), and self-administered questionnaires. A significant improvement (p = .028) after the intervention period for the chair sit and reach test was found, such improvement was maintained after the detraining phase. Tenderness, symptomatology, and quality of life did not significantly change after the intervention period or the detraining phase. In summary, a 4-month Tai Chi intervention improved lower body flexibility in men with fibromyalgia. This improvement persisted after the detraining period.

Dance-Based Exercise and Tai Chi and Their Benefits for People with Arthritis: A Review

ERIC Educational Resources Information Center

Marks, Ray

2005-01-01

Purpose: The first aim of this review article is to systematically summarise, synthesise, and critically evaluate the research base concerning the use of two art forms, namely, dance-based exercises and Tai Chi, as applied to people with arthritis (a chronic condition that results in considerable disability and, particularly in later life,…

The effect of Tai Chi Chuan in reducing falls among elderly people: design of a randomized clinical trial in the Netherlands [ISRCTN98840266].

PubMed

Zeeuwe, Petra E M; Verhagen, Arianne P; Bierma-Zeinstra, Sita Ma; van Rossum, Erik; Faber, Marjan J; Koes, Bart W

2006-03-30

Falls are a significant public health problem. Thirty to fifty percent of the elderly of 65 years and older fall each year. Falls are the most common type of accident in this age group and can result in fractures and subsequent disabilities, increased fear of falling, social isolation, decreased mobility, and even an increased mortality. Several forms of exercise have been associated with a reduced risk of falling and with a wide range of physiological as well as psychosocial health benefits. Tai Chi Chuan seems to be the most promising form of exercise in the elderly, but the evidence is still controversial. In this article the design of a randomized clinical trial is presented. The trial evaluates the effect of Tai Chi Chuan on fall prevention and physical and psychological function in older adults. 270 people of seventy years and older living at home will be identified in the files of the participating general practitioners. People will be asked to participate when meeting the following inclusion criteria: have experienced a fall in the preceding year or suffer from two of the following risk factors: disturbed balance, mobility problems, dizziness, or the use of benzodiazepines or diuretics. People will be randomly allocated to either the Tai Chi Chuan group (13 weeks, twice a week) or the no treatment control group. The primary outcome measure is the number of new falls, measured with a diary. The secondary outcome measures are balance, fear of falling, blood pressure, heart rate, lung function parameters, physical activity, functional status, quality of life, mental health, use of walking devices, medication, use of health care services, adjustments to the house, severity of fall incidents and subsequent injuries. Process parameters will be measured to evaluate the Tai Chi Chuan intervention. A cost-effectiveness analysis will be carried out alongside the evaluation of the clinical results. Follow-up measurements will be collected at 3, 6 and 12 months after

Tai Chi: moving for better balance -- development of a community-based falls prevention program.

PubMed

Li, Fuzhong; Harmer, Peter; Mack, Karin A; Sleet, David; Fisher, K John; Kohn, Melvin A; Millet, Lisa M; Xu, Junheng; Yang, Tingzhong; Sutton, Beth; Tompkins, Yvaughn

2008-05-01

This study was designed to develop an evidence- and community based falls prevention program -- Tai Chi: Moving for Better Balance. A mixed qualitative and quantitative approach was used to develop a package of materials for program implementation and evaluation. The developmental work was conducted in 2 communities in the Pacific Northwest. Participants included a panel of experts, senior service program managers or activity coordinators, and older adults. Outcome measures involved program feasibility and satisfaction. Through an iterative process, a program package was developed. The package contained an implementation plan and class training materials (ie, instructor's manual, videotape, and user's guidebook). Pilot testing of program materials showed that the content was appropriate for the targeted users (community-living older adults) and providers (local senior service organizations). A feasibility survey indicated interest and support from users and providers for program implementation. A 2-week pilot evaluation showed that the program implementation was feasible and evidenced good class attendance, high participant satisfaction, and interest in continuing Tai Chi. The package of materials developed in this study provides a solid foundation for larger scale implementation and evaluation of the program in community settings.

Facilitators and Barriers to Tai Chi in an Older Adult Community: A Theory-Driven Approach

ERIC Educational Resources Information Center

Gryffin, Pete A.; Chen, William C.; Chaney, Beth H.; Dodd, Virginia J.; Roberts, Beverly

2015-01-01

Background: Prevention has been identified as a primary strategy for reducing health care costs, with potential Medicare savings up to $142.8 billion annually. Falls alone resulted in $28.2 billion in direct care costs. A growing body of research documents significant benefits of tai chi (TC) for balance and prevention and management of chronic…

Estimation of lifetime of carbonaceous aerosol from open crop residue burning during Mount Tai Experiment 2006 (MTX2006)

NASA Astrophysics Data System (ADS)

Pan, X. L.; Kanaya, Y.; Wang, Z. F.; Komazaki, Y.; Taketani, F.; Akimoto, H.; Pochanart, P.; Liu, Y.

2012-06-01

Studying the emission ratios of carbonaceous aerosols (element carbon, EC, and organic carbon, OC) from open biomass burning helps to reduce uncertainties in emission inventories and provides necessary constraints for model simulations. We measured apparent elemental carbon (ECa) and OC concentrations at the summit of Mount Tai (Mt. Tai) during intensive open crop residue burning (OCRB) episodes using a Sunset OCEC analyzer. Equivalent black carbon (BCe) concentrations were determined using a Multiple Angle Absorption Photometer (MAAP). In the fine particle mode, OC and EC showed strong correlations (r > 0.9) with carbon monoxide (CO). Footprint analysis using the FLEXPART_WRF model indicated that OCRB in central east China (CEC) had a significant influence on ambient carbonaceous aerosol loadings at the summit of Mt. Tai. ΔECa/ΔCO ratios resulting from OCRB plumes were 14.3 ± 1.0 ng m-3 ppbv-1 at Mt. Tai. This ratio was more than three times those resulting from urban pollution in CEC, demonstrating that significant concentrations of soot particles were released from OCRB. ΔOC/ΔCO ratio from fresh OCRB plumes was found to be 41.9 ± 2.6 ng m-3 ppbv-1 in PM1. The transport time of smoke particles was estimated using the FLEXPART_WRF tracer model by releasing inert particles from the ground layer inside geographical regions where large numbers of hotspots were detected by a MODIS satellite sensor. Fitting regressions using the e-folding exponential function indicated that the removal efficiency of OC (normalized to CO) was much larger than that of ECa mass, with mean lifetimes of 27 h (1.1 days) for OC and 105 h (4.3 days) for ECa, respectively. The lifetime of black carbon estimated for the OCRB events in east China was comparably lower than the values normally adopted in the transport models. Short lifetime of organic carbon highlighted the vulnerability of OC to cloud scavenging in the presence of water-soluble organic species from biomass combustion.

Study design for a randomised controlled trial to explore the modality and mechanism of Tai Chi in the pulmonary rehabilitation of chronic obstructive pulmonary disease.

PubMed

Fu, Juan-Juan; Min, Jie; Yu, Peng-Ming; McDonald, Vanessa M; Mao, Bing

2016-08-04

Although pulmonary rehabilitation (PR) is associated with significant clinical benefits in chronic obstructive pulmonary disease (COPD) and has been recommended by guidelines, PR with conventional exercise training has not been widely applied in the clinic because of its inherent limitations. Alternative exercise such as Tai Chi has been investigated and the results are promising. However, the strengths and weaknesses of the exercise modality of Tai Chi, conventional PR and a combination of Tai Chi and conventional PR and the possible mechanisms underlying Tai Chi exercise remain unclear. This study aims to address the above research gaps in a well-designed clinical trial. This study is a single-blind, randomised controlled trial. Participants with stable COPD will be recruited and randomly assigned to one of four groups receiving Tai Chi exercise, conventional PR using a total body recumbent stepper (TBRS), combined Tai Chi and TBRS, or usual care (control) in a 1:1:1:1 ratio. Participants will perform 30 min of supervised exercise three times a week for 8 weeks; they will receive sequential follow-ups until 12 months after recruitment. The primary outcome will be health-related quality of life as measured by the St George's Respiratory Questionnaire. Secondary outcomes will include 6 min walking distance, pulmonary function, the modified Medical Research Council Dyspnoea Scale, the COPD Assessment Test, the Hospital Anxiety and Depression Scale, the Berg Balance Scale, exacerbation frequency during the study period, and systemic inflammatory and immune markers. Ethics approval has been granted by the Clinical Trial and Biomedical Ethics Committee of West China Hospital of Sichuan University (No TCM-2015-82). Written informed consent will be obtained from each participant before any procedures are performed. The study findings will be published in peer-reviewed journals and presented at national and international conferences. ChiCTR-IOR-15006874; Pre

Everybody was Kung-Fu fighting-The beneficial effects of Tai Chi Qigong and self-defense Kung-Fu training on psychological and endocrine health in middle aged and older men.

PubMed

Walther, A; Lacker, T J; Ehlert, U

2018-02-01

Higher age is associated to a variety of physical and mental disorders. Age-related changes in steroid secretion have been suggested to be an underlying mechanism leading to frailty, depression, and sexual dysfunction. However, Tai chi qigong and similar forms of exercise have been shown to improve a great variety of health-related parameters in older individuals. We examined 56 self-reporting healthy men actively practicing Tai chi qigong and/or self-defense Kung-fu and 55 age-matched self-reporting healthy controls. Saliva samples were obtained in a standardized procedure for subsequent quantification of circulating testosterone and cortisol levels. In addition, depressive symptoms, life satisfaction, and sexual health were assessesd via self-report questionnaires. Age was negatively associated with testosterone, while no association emerged for cortisol. Tai chi qigong and/or self-defense Kung-fu training was neither associated with testosterone nor cortisol. More weekly Tai chi qigong and/or self-defense Kung-fu training (4 or more times per week) was instead associated with a lower CT-ratio, less depressive symptoms, and higher life satisfaction compared to individuals, who trained only one to three times per week. More years of Tai chi qigong and/or self-defense Kung-fu training were associated with less depressive symptoms and higher life satisfaction but not with the CT-ratio. No significant associations emerged for Tai chi qigong and/or self-defense Kung-fu training and sexual health. When compared to the age-matched controls, there is a significant effect of Tai chi, qigong and/or self-defense Kung-fu on the CT-ratio. Contrast analyses revealed a significantly lower CT-ratio for the high training load group in contrast to the low training load group. Further, in contrast to the control group, the low training load group exhibits a significantly higher CT-ratio. For depression, contrast analyses revealed a significantly lower level of depression in the

The benefits of Tai Chi and brisk walking for cognitive function and fitness in older adults

PubMed Central

Ji, Zhiguang; Feng, Tian; Liu, Xiaolei; You, Yihong; Meng, Fanying; Wang, Ruoqing; Lu, Jialing

2017-01-01

The purpose of this study was to investigate the benefits of exercises with different cognitive demands for cognitive functions (Executive and non-Executive) in healthy older adults. A cross-sectional design was adopted. In total, 84 healthy older adults were enrolled in the study. They were categorized into the Tai Chi group (TG), the brisk walking group (BG) or the control group (CG). Each participant performed the Stroop task and a digit comparison task. The Stroop task included the following three conditions: a naming condition, an inhibition condition and an executive condition. There were two experimental conditions in the digit comparison task: the non-delay condition and the delay condition. The results indicated that participants of the TG and BG revealed significant better performance than the CG in the executive condition of cognitive tasks and fitness. There was no significant difference of reaction time (RT) and accuracy rate in the inhibition and delay conditions of cognitive tasks and fitness between the TG and BG. The TG showed shorter reaction time in the naming and the executive conditions, and more accurate in the inhibition conditions than the BG. These findings demonstrated that regular participation in brisk walking and Tai Chi have significant beneficial effects on executive function and fitness. However, due to the high cognitive demands of the exercise, Tai Chi benefit cognitive functions (Executive and non-Executive) in older adults more than brisk walking does. Further studies should research the underlying mechanisms at the behavioural and neuroelectric levels, providing more evidence to explain the effect of high-cognitive demands exercise on different processing levels of cognition. PMID:29062610

Occurrence of additive brominated flame retardants in aquatic organisms from Tai Lake and Yangtze River in Eastern China, 2009-2012.

PubMed

Su, Guanyong; Saunders, David; Yu, Yijun; Yu, Hongxia; Zhang, Xiaowei; Liu, Hongling; Giesy, John P

2014-11-01

Since the phase-out of PBDEs, reports regarding occurrences of these compounds in the environment have become less frequent. To characterize potential influences of the phase-out of PBDEs' on concentrations in the environment, trends in concentrations as a function of time were investigated for two additive brominated flame retardants, PBDEs and HBCDs. Three aquatic species, including shrimp, common carp, and yellow catfish, were collected from Meiliang Bay of Tai Lake, 2009-2012. The analysis of PBDEs in three aquatic organisms has shown a downward-trend in the first three years but a significant upward-trend in the final year. Concentrations of HBCDs have not shown temporal increases in the investigated environments. Concentrations of both PBDEs and HBCDs in the three studied organisms increased as a function of trophic level, which suggested that these additive flame retardants can be biomagnified through the food web of Tai Lake. In accordance with previous publications, PBDE-47 contributed the greatest proportion of ∑PBDEs and had a detection frequency of 100%. α-HBCD was the predominate isomer that contributed to ∑HBCDs. Both β-HBCD and γ-HBCD were likely detected at lesser concentrations than the α-isomer due to differences in bioavailability. Concentrations of ∑PBDEs in the three aquatic organisms from Tai Lake ranged from 1.13 to 97.59 ng g(-1) lipid. These concentrations were generally less than those in biota from other countries, but equal to those found at other locations in China. Specimens from the Yangtze River had greater concentrations of ∑HBCDs (169.6-316.5 ng g(-1) lipid) than those collected at Tai Lake, which were comparatively greater than many reported concentrations in freshwater organisms from other countries. Copyright © 2014 Elsevier Ltd. All rights reserved.

A systems biology approach to studying Tai Chi, physiological complexity and healthy aging: design and rationale of a pragmatic randomized controlled trial.

PubMed

Wayne, Peter M; Manor, Brad; Novak, Vera; Costa, Madelena D; Hausdorff, Jeffrey M; Goldberger, Ary L; Ahn, Andrew C; Yeh, Gloria Y; Peng, C-K; Lough, Matthew; Davis, Roger B; Quilty, Mary T; Lipsitz, Lewis A

2013-01-01

Aging is typically associated with progressive multi-system impairment that leads to decreased physical and cognitive function and reduced adaptability to stress. Due to its capacity to characterize complex dynamics within and between physiological systems, the emerging field of complex systems biology and its array of quantitative tools show great promise for improving our understanding of aging, monitoring senescence, and providing biomarkers for evaluating novel interventions, including promising mind-body exercises, that treat age-related disease and promote healthy aging. An ongoing, two-arm randomized clinical trial is evaluating the potential of Tai Chi mind-body exercise to attenuate age-related loss of complexity. A total of 60 Tai Chi-naïve healthy older adults (aged 50-79) are being randomized to either six months of Tai Chi training (n=30), or to a waitlist control receiving unaltered usual medical care (n=30). Our primary outcomes are complexity-based measures of heart rate, standing postural sway and gait stride interval dynamics assessed at 3 and 6months. Multiscale entropy and detrended fluctuation analysis are used as entropy- and fractal-based measures of complexity, respectively. Secondary outcomes include measures of physical and psychological function and tests of physiological adaptability also assessed at 3 and 6months. Results of this study may lead to novel biomarkers that help us monitor and understand the physiological processes of aging and explore the potential benefits of Tai Chi and related mind-body exercises for healthy aging. Copyright © 2012 Elsevier Inc. All rights reserved.

Effect of migration patterns on maternal genetic structure: a case of Tai-Kadai migration from China to Thailand.

PubMed

Kampuansai, Jatupol; Kutanan, Wibhu; Tassi, Francesca; Kaewgahya, Massupa; Ghirotto, Silvia; Kangwanpong, Daoroong

2017-02-01

The migration of the Tai-Kadai speaking people from southern China to northern Thailand over the past hundreds of years has revealed numerous patterns that have likely been influenced by routes, purposes and periods of time. To study the effects of different migration patterns on Tai-Kadai maternal genetic structure, mitochondrial DNA hypervariable region I sequences from the Yong and the Lue people having well-documented histories in northern Thailand were analyzed. Although the Yong and Lue people were historically close relatives who shared Xishuangbanna Dai ancestors, significant genetic differences have been observed among them. The Yong people who have been known to practice mass migration have exhibited a closer genetic affinity to their Dai ancestors than have the Lue people. Genetic heterogeneity and a sudden reduced effective population size within the Lue group is likely a direct result of the circumstances of the founder effect.

Comparative impacts of Tai Chi, balance training, and a specially-designed yoga program on balance in older fallers.

PubMed

Ni, Meng; Mooney, Kiersten; Richards, Luca; Balachandran, Anoop; Sun, Mingwei; Harriell, Kysha; Potiaumpai, Melanie; Signorile, Joseph F

2014-09-01

To compare the effect of a custom-designed yoga program with 2 other balance training programs. Randomized controlled trial. Research laboratory. A group of older adults (N=39; mean age, 74.15 ± 6.99 y) with a history of falling. Three different exercise interventions (Tai Chi, standard balance training, yoga) were given for 12 weeks. Balance performance was examined during pre- and posttest using field tests, including the 8-foot up-and-go test, 1-leg stance, functional reach, and usual and maximal walking speed. The static and dynamic balances were also assessed by postural sway and dynamic posturography, respectively. Training produced significant improvements in all field tests (P<.005), but group difference and time × group interaction were not detected. For postural sway, significant decreases in the area of the center of pressure with eyes open (P=.001) and eyes closed (P=.002) were detected after training. For eyes open, maximum medial-lateral velocity significantly decreased for the sample (P=.013). For eyes closed, medial-lateral displacement decreased for Tai Chi (P<.01). For dynamic posturography, significant improvements in overall score (P=.001), time on the test (P=.006), and 2 linear measures in lateral (P=.001) and anterior-posterior (P<.001) directions were seen for the sample. Yoga was as effective as Tai Chi and standard balance training for improving postural stability and may offer an alternative to more traditional programs. Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Participation trends in holistic movement practices: a 10-year comparison of yoga/Pilates and t'ai chi/qigong use among a national sample of 195,926 Australians.

PubMed

Vergeer, Ineke; Bennie, Jason A; Charity, Melanie J; Harvey, Jack T; van Uffelen, Jannique G Z; Biddle, Stuart J H; Eime, Rochelle M

2017-06-06

In recent decades, the evidence supporting the physical and mental health benefits of holistic movement practices such as yoga and t'ai chi have become increasingly established. Consequently, investigating the participation prevalence and patterns of these practices is a relevant pursuit in the public health field. Few studies have provided population-level assessment of participation rates, however, and even fewer have focused on patterns over time. The purpose of this study was to examine participation prevalence and trends in yoga/Pilates and t'ai chi/qigong over a ten-year period in a nationally representative sample of Australians aged 15 years and over, with particular attention to sex and age. A secondary purpose was to juxtapose these findings with participation trends in traditional fitness activities over the same period. Data comprised modes and types of physical activity, age, and sex variables collected through the Exercise, Recreation and Sport Survey (ERASS), a series of independent cross-sectional Australia-wide surveys conducted yearly between 2001 and 2010. For each year, weighted population estimates were calculated for those participating in yoga/Pilates, t'ai chi/qigong, and fitness activities (e.g. aerobics, calisthenics). Linear regression and multiple logistic regression analyses were used to examine trends in prevalence rates over time and differences among sex and age (15-34; 35-54; 55+ years) groups, respectively. Average prevalence rates between 2001 and 2010 were 3.0% (95% CI 2.9-3.1) for yoga/Pilates, 0.6% (95% CI 0.5-0.6) for t'ai chi/qigong, and 19.2% (95% CI 18.9-19.4) for fitness activities. Across the decade, overall participation rates remained relatively stable for yoga/Pilates and t'ai chi/qigong, while increasing linearly for fitness activities. For both genders and in all three age groups, participation in fitness activities increased, whereas only in the 55+ age group was there a significant increase in yoga

The experiment of cooperative learning model type team assisted individualization (TAI) on three-dimensional space subject viewed from spatial intelligence

NASA Astrophysics Data System (ADS)

Manapa, I. Y. H.; Budiyono; Subanti, S.

2018-03-01

The aim of this research is to determine the effect of TAI or direct learning (DL) on student’s mathematics achievement viewed from spatial intelligence. This research was quasi experiment. The population was 10th grade senior high school students in Alor Regency on academic year of 2015/2016 chosen by stratified cluster random sampling. The data were collected through achievement and spatial intelligence test. The data were analyzed by two ways, ANOVA with unequal cell and scheffe test. This research showed that student’s mathematics achievement used in TAI had better results than DL models one. In spatial intelligence category, student’s mathematics achievement with high spatial intelligence has better result than the other spatial intelligence category and students with high spatial intelligence have better results than those with middle spatial intelligence category. At TAI, student’s mathematics achievement with high spatial intelligence has better result than those with the other spatial intelligence category and students with middle spatial intelligence have better results than students with low spatial intelligence. In DL model, student’s mathematics achievement with high and middle spatial intelligence has better result than those with low spatial intelligence, but students with high spatial intelligence and middle spatial intelligence have no significant difference. In each category of spatial intelligence and learning model, mathematics achievement has no significant difference.

Comprehensive theoretical studies on the low-lying electronic states of NiF, NiCl, NiBr, and NiI.

PubMed

Zou, Wenli; Liu, Wenjian

2006-04-21

The low-lying electronic states of the nickel monohalides, i.e., NiF, NiCl, NiBr, and NiI, are investigated by using multireference second-order perturbation theory with relativistic effects taken into account. For the energetically lowest 11 lambda-S states and 26 omega states there into, the potential energy curves and corresponding spectroscopic constants (vertical and adiabatic excitation energies, equilibrium bond lengths, vibrational frequencies, and rotational constants) are reported. The calculated results are grossly in very good agreement with those solid experimental data. In particular, the ground state of NiI is shown to be different from those of NiF, NiCl, and NiBr, being in line with the recent experimental observation. Detailed analyses are provided on those states that either have not been assigned or have been incorrectly assigned by previous experiments.

Assessing the comparative effectiveness of Tai Chi versus physical therapy for knee osteoarthritis: design and rationale for a randomized trial.

PubMed

Wang, Chenchen; Iversen, Maura D; McAlindon, Timothy; Harvey, William F; Wong, John B; Fielding, Roger A; Driban, Jeffrey B; Price, Lori Lyn; Rones, Ramel; Gamache, Tressa; Schmid, Christopher H

2014-09-08

Knee osteoarthritis (OA) causes pain and long-term disability with annual healthcare costs exceeding $185 billion in the United States. Few medical remedies effectively influence the course of the disease. Finding effective treatments to maintain function and quality of life in patients with knee OA is one of the national priorities identified by the Institute of Medicine. We are currently conducting the first comparative effectiveness and cost-effectiveness randomized trial of Tai Chi versus a physical-therapy regimen in a sample of patients with symptomatic and radiographically confirmed knee OA. This article describes the design and conduct of this trial. A single-center, 52-week, comparative effectiveness randomized controlled trial of Tai Chi versus a standardized physical-therapy regimen is being conducted at an urban tertiary medical center in Boston, Massachusetts. The study population consists of adults ≥ 40 years of age with symptomatic and radiographic knee OA (American College of Rheumatology criteria). Participants are randomly allocated to either 12 weeks of Tai Chi (2x/week) or Physical Therapy (2x/week for 6 weeks, followed by 6 weeks of rigorously monitored home exercise). The primary outcome measure is pain (Western Ontario and McMaster Universities WOMAC) subscale at 12 weeks. Secondary outcomes include WOMAC stkiffness and function domain scores, lower extremity strength and power, functional balance, physical performance tests, psychological and psychosocial functioning, durability effects, health related quality of life, and healthcare utilization at 12, 24 and 52 weeks. This study will be the first randomized comparative-effectiveness and cost-effectiveness trial of Tai Chi versus Physical Therapy in a large symptomatic knee OA population with long-term follow up. We present here a robust and well-designed randomized comparative-effectiveness trial that also explores multiple outcomes to elucidate the potential mechanisms of mind

Effects of tai chi qigong on psychosocial well-being among hidden elderly, using elderly neighborhood volunteer approach: a pilot randomized controlled trial.

PubMed

Chan, Aileen Wk; Yu, Doris Sf; Choi, K C

2017-01-01

To test the feasibility and preliminary effectiveness of a tai chi qigong program with the assistance of elderly neighborhood volunteers in strengthening social networks and enhancing the psychosocial well-being of hidden elderly. "Hidden elderly" is a term used to describe older adults who are socially isolated and refuse social participation. This pilot randomized controlled trial recruited 48 older adults aged 60 or above who did not engage in any social activity. They were randomized into tai chi qigong (n=24) and standard care control (n=24) groups. The former group underwent a three-month program of two 60-minute sessions each week, with the socially active volunteers paired up with them during practice. Standard care included regular home visits by social workers. Primary outcomes were assessed by means of the Lubben social network and De Jong Gieveld loneliness scales, and by a revised social support questionnaire. Secondary outcomes were covered by a mental health inventory and the Rosenberg self-esteem scale, and quality of life by using the 12-Item Short Form Health Survey. Data was collected at baseline, and at three and six months thereafter. The generalized estimating equations model revealed general improvement in outcomes among participants on the tai chi qigong program. In particular, participants reported a significantly greater improvement on the loneliness scale ( B =-1.32, 95% confidence interval [CI] -2.54 to -0.11, P =0.033) and the satisfaction component of the social support questionnaire ( B =3.43, 95% CI 0.10-6.76, P =0.044) than the control group. The pilot study confirmed that tai chi qigong with elderly neighborhood volunteers is a safe and feasible social intervention for hidden elderly. Its potential benefits in improving social and psychological health suggest the need for a full-scale randomized controlled trial to reveal its empirical effects.

The effect of Tai Chi on four chronic conditions-cancer, osteoarthritis, heart failure and chronic obstructive pulmonary disease: a systematic review and meta-analyses.

PubMed

Chen, Yi-Wen; Hunt, Michael A; Campbell, Kristin L; Peill, Kortni; Reid, W Darlene

2016-04-01

Many middle-aged and older persons have more than one chronic condition. Thus, it is important to synthesise the effectiveness of interventions across several comorbidities. The aim of this systematic review was to summarise current evidence regarding the effectiveness of Tai Chi in individuals with four common chronic conditions-cancer, osteoarthritis (OA), heart failure (HF) and chronic obstructive pulmonary disease (COPD). 4 databases (MEDLINE, EMBASE, CINAHL and SPORTDiscus) were searched for original articles. Two reviewers independently screened the titles and abstracts and then conducted full-text reviews, quality assessment and finally data abstraction. 33 studies met the inclusion criteria. Meta-analyses were performed on disease-specific symptoms, physiological outcomes and physical performance of each chronic condition. Subgroup analyses on disease-specific symptoms were conducted by categorising studies into subsets based on the type of comparison groups. Meta-analyses showed that Tai Chi improved or showed a tendency to improve physical performance outcomes, including 6-min walking distance (6MWD) and knee extensor strength, in most or all four chronic conditions. Tai Chi also improved disease-specific symptoms of pain and stiffness in OA. The results demonstrated a favourable effect or tendency of Tai Chi to improve physical performance and showed that this type of exercise could be performed by individuals with different chronic conditions, including COPD, HF and OA. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Qigong/Tai Chi Easy for fatigue in breast cancer survivors: Rationale and design of a randomized clinical trial.

PubMed

Larkey, Linda; Huberty, Jennifer; Pedersen, Maja; Weihs, Karen

2016-09-01

Breast cancer survivors (BCSs) often report fatigue that persists for years following treatment. Despite a growing body of evidence for meditative movement practices to improve symptoms among BCSs, few studies have explored using Qigong/Tai Chi to reduce fatigue. Additionally, few have examined the biological mechanisms through which fatigue may be reduced using Qigong/Tai Chi. We will recruit 250 fatigued, post-menopausal women diagnosed with breast cancer (stage 0-III), between 6months and 5years past primary treatment and randomize to a standardized Qigong/Tai Chi Easy (QG/TCE) intervention, a "sham" Qigong group (movements without a focus on the breath and meditative state) (SQG), or an educational support (ES) group. The primary outcome (fatigue), secondary outcomes (anxiety, depression, sleep quality, cognitive function, physical activity), and a biomarker of HPA axis dysregulation (diurnal cortisol) will be assessed at baseline, post-intervention and 6months postintervention, and biomarkers of inflammation (IL1ra, IL6, TNFα and INFᵧ) at pre/post-intervention. We hypothesize that QG/TCE will reduce fatigue (and improve other symptoms associated with fatigue) in BCSs experiencing persistent cancer-related fatigue more than SQG and ES. Biomarkers will be examined for relationships to changes in fatigue. Findings from this study may reveal the effects of the unique mind-body aspects of QG/TCE on fatigue in BCSs with a complex design that separates the effects of low-intensity physical activity (SQG) and social support/attention (ES) from the primary intervention. Further, results will likely contribute greater understanding of the biological mechanisms of these practices related to improved symptoms among BCSs. Copyright © 2016 Elsevier Inc. All rights reserved.

Comparison of tai chi vs. strength training for fall prevention among female cancer survivors: study protocol for the GET FIT trial

PubMed Central

2012-01-01

Background Women with cancer are significantly more likely to fall than women without cancer placing them at higher risk of fall-related fractures, other injuries and disability. Currently, no evidence-based fall prevention strategies exist that specifically target female cancer survivors. The purpose of the GET FIT (Group Exercise Training for Functional Improvement after Treatment) trial is to compare the efficacy of two distinct types of exercise, tai chi versus strength training, to prevent falls in women who have completed treatment for cancer. The specific aims of this study are to: 1) Determine and compare the efficacy of both tai chi training and strength training to reduce falls in older female cancer survivors, 2) Determine the mechanism(s) by which tai chi and strength training each reduces falls and, 3) Determine whether or not the benefits of each intervention last after structured training stops. Methods/Design We will conduct a three-group, single-blind, parallel design, randomized controlled trial in women, aged 50–75 years old, who have completed chemotherapy for cancer comparing 1) tai chi 2) strength training and 3) a placebo control group of seated stretching exercise. Women will participate in supervised study programs twice per week for six months and will be followed for an additional six months after formal training stops. The primary outcome in this study is falls, which will be prospectively tracked by monthly self-report. Secondary outcomes are maximal leg strength measured by isokinetic dynamometry, postural stability measured by computerized dynamic posturography and physical function measured by the Physical Performance Battery, all measured at baseline, 3, 6 and 12 months. The sample for this trial (N=429, assuming 25% attrition) will provide adequate statistical power to detect at least a 47% reduction in the fall rate over 1 year by being in either of the 2 exercise groups versus the control group. Discussion The GET FIT trial

First principles exploration of NiO and its ions NiO+ and NiO-

NASA Astrophysics Data System (ADS)

Sakellaris, Constantine N.; Mavridis, Aristides

2013-02-01

We present a high level ab initio study of NiO and its ions, NiO+ and NiO-. Employing variational multireference configuration interaction (MRCI) and single reference coupled-cluster methods combined with basis sets of quintuple quality, 54, 20, and 10 bound states of NiO, NiO+, and NiO- have been studied. For all these states, complete potential energy curves have been constructed at the MRCI level of theory; in addition, for the ground states of the three species core subvalence (3s23p6/Ni) and scalar relativistic effects have been taken into account. We report energetics, spectroscopic parameters, dipole moments, and spin-orbit coupling constants. The agreement with experiment is in the case of NiO good, but certain discrepancies that need further investigation have arisen in the case of the anion whose ground state remains computationally a tantalizing matter. The cation is experimentally almost entirely unexplored, therefore, the study of many states shall prove valuable to further investigators. The ground state symmetry, bond distances, and binding energies of NiO and NiO+ are (existing experimental values in parenthesis), X3Σ-(X3Σ-), re = 1.606 (1.62712) Å, D0 = 88.5 (89.2 ± 0.7) kcal/mol, and X4Σ-(?), re = 1.60(?) Å, D0 = 55 (62.4 ± 2.4) kcal/mol, respectively. The ground state of NiO- is 4Σ- (but 2Π experimentally) with D0 = 85-87 (89.2 ± 0.7) kcal/mol.

Coping with future epidemics: Tai chi practice as an overcoming strategy used by survivors of severe acute respiratory syndrome (SARS) in post-SARS Hong Kong.

PubMed

Siu, Judy Yuen-Man

2016-06-01

Although SARS had been with a controversial topic for a decade at the time of this study, numerous SARS survivors had not yet physically, psychologically or socially recovered from the aftermath of SARS. Among chronically ill patients, the use of complementary and alternative medicine (CAM) is reported to be widespread. However, extremely little is known about the use of CAM by SARS survivors in the post-SARS period and even less is known about how the use of CAM is related to the unpleasant social and medical-treatment experiences of SARS survivors, their eagerness to re-establish social networks, and their awareness to prepare for future epidemics. To investigate the motivations for practising tai chi among SARS survivors in post-SARS Hong Kong. Using a qualitative approach, I conducted individual semi-structured interviews with 35 SARS survivors, who were purposively sampled from a tai chi class of a SARS-patient self-help group in Hong Kong. Health concerns and social experiences motivated the participants to practise tai chi in post-SARS Hong Kong. Experiencing health deterioration in relation to SARS-associated sequelae, coping with unpleasant experiences during follow-up biomedical treatments, a desire to regain an active role in recovery and rehabilitation, overcoming SARS-associated stigmas by establishing a new social network and preparing for potential future stigmatization and discrimination were the key motivators for them. The participants practised tai chi not only because they sought to improve their health but also because it provided a crucial social function and meaning to them. © 2014 John Wiley & Sons Ltd.

The oxidation of Ni-rich Ni-Al intermetallics

NASA Technical Reports Server (NTRS)

Doychak, Joseph; Smialek, James L.; Barrett, Charles A.

1988-01-01

The oxidation of Ni-Al intermetallic alloys in the beta-NiAl phase field and in the two phase beta-NiAl/gamma'-Ni3Al phase field has been studied between 1000 and 1400 C. The stoichiometric beta-NiAl alloy doped with Zr was superior to other alloy compositions under cyclic and isothermal oxidation. The isothermal growth rates did not increase monotonically as the alloy Al content was decreased. The characteristically ridged alpha-Al2O3 scale morphology, consisting of cells of thin, textured oxide with thick growth ridges at cell boundaries, forms on oxidized beta-NiAl alloys. The correlation of scale features with isothermal growth rates indicates a predominant grain boundary diffusion growth mechanism. The 1200 C cyclic oxidation resistance decreases near the lower end of the beta-NiAl phase field.

Direct Experimental Probe of the Ni(II)/Ni(III)/Ni(IV) Redox Evolution in LiNi 0.5Mn 1.5O 4 Electrodes

DOE PAGES

Qiao, Ruimin; Wray, L. Andrew; Kim, Jung -Hyun; ...

2015-11-11

The LiNi 0.5Mn 1.5O 4 spinel is an appealing cathode material for next generation rechargeable Li-ion batteries due to its high operating voltage of ~4.7 V (vs Li/Li +). Although it is widely believed that the full range of electrochemical cycling involves the redox of Ni(II)/(IV), it has not been experimentally clarified whether Ni(III) exists as the intermediate state or a double-electron transfer takes place. Here, combined with theoretical calculations, we show unambiguous spectroscopic evidence of the Ni(III) state when the LiNi 0.5Mn 1.5O 4 electrode is half charged. This provides a direct verification of single-electron-transfer reactions in LiNi 0.5Mnmore » 1.5O 4 upon cycling, namely, from Ni(II) to Ni(III), then to Ni(IV). Additionally, by virtue of its surface sensitivity, soft X-ray absorption spectroscopy also reveals the electrochemically inactive Ni 2+ and Mn 2+ phases on the electrode surface. Our work provides the long-awaited clarification of the single-electron transfer mechanism in LiNi 0.5Mn 1.5O 4 electrodes. Furthermore, the experimental results serve as a benchmark for further spectroscopic characterizations of Ni-based battery electrodes.« less

Efficacy of practising Tai Chi for older people with mild dementia: protocol for a randomised controlled study.

PubMed

Lyu, Jihui; Li, Wenjie; Rong, Xiangjiang; Wei, Lian; Huang, Nayan; Champ, Mei; Xiong, Qian; Chen, Xueli; Li, Mo; Li, Fangling

2018-05-14

Many studies suggest that Tai Chi exercise is a safe and appropriate mind-body exercise for older people and effectively slows down age-related cognitive decline. A set of bespoke Tai Chi exercise named 'Cognition Protecting Tai Chi' (CPT) has been created for older people with cognitive impairments by the research team of geriatricians, neurologists, rehabilitation specialists, experts of sports medicine and experienced practitioners of traditional Chinese medicine. This trial is designed to evaluate its effects on cognitive function, behaviour/moods, risk of falls and activities of daily living of the participants with mild dementia. A randomised controlled study will be conducted. Eighty participants with mild dementia will be recruited and randomly allocated to an intervention group and a control group. The intervention group will practice the CPT exercise three times a week for 20 min each time under the guidance of professional therapists. The control group will continue receiving their routine treatments. The duration of this study will be 10 months. All participants will be assessed with a battery of neuropsychological and functional evaluations, which include Mini Mental State Examination, Montreal Cognitive Assessment, the WHO-University of California Los Angeles-Auditory Verbal Learning test (WHO-UCLA-AVLT), Trail Making Test (TMT), Geriatric Depression Scale, Neuropsychological Inventory and Barthel Index, at the baseline, 5 and 10 months during the study period. Fall incident will also be recorded. The primary outcome will be the WHO-UCLA-AVLT delayed recall score. The secondary outcome will be the TMT score. This study has been approved by the ethical review committee of the Beijing Geriatric Hospital (protocol number: 2015-021). Informed consent will be obtained from all participants or their guardians. The authors intend to submit the findings of the study to peer-reviewed journals or academic conferences to be published. ChiCTR-INR-16009872; Pre

Development of B2 Shape Memory Intermetallics Beyond NiAl, CoNiAl and CoNiGa

NASA Astrophysics Data System (ADS)

Gerstein, G.; Firstov, G. S.; Kosorukova, T. A.; Koval, Yu. N.; Maier, H. J.

2018-06-01

The present study describes the development of shape memory alloys based on NiAl. Initially, this system was considered a promising but unsuccessful neighbour of NiTi. Later, however, shape memory alloys like CoNiAl or CoNiGa were developed that can be considered as NiAl derivatives and already demonstrated good mechanical properties. Yet, these alloys were still inferior to NiTi in most respects. Lately, using a multi-component approach, a CoNiCuAlGaIn high entropy intermetallic compound was developed from the NiAl prototype. This new alloy featured a B2 phase and a martensitic transformation along with a remarkable strength in the as-cast state. In the long-term, this new approach might led to a breakthrough for shape memory alloys in general.

Point defect evolution in Ni, NiFe and NiCr alloys from atomistic simulations and irradiation experiments

DOE PAGES

Aidhy, Dilpuneet S.; Lu, Chenyang; Jin, Ke; ...

2015-08-08

Using molecular dynamics simulations, we elucidate irradiation-induced point defect evolution in fcc pure Ni, Ni 0.5Fe 0.5, and Ni 0.8Cr 0.2 solid solution alloys. We find that irradiation-induced interstitials form dislocation loops that are of 1/3 <111>{111}-type, consistent with our experimental results. While the loops are formed in all the three materials, the kinetics of formation is considerably slower in NiFe and NiCr than in pure Ni, indicating that defect migration barriers and extended defect formation energies could be higher in the alloys than pure Ni. As a result, while larger size clusters are formed in pure Ni, smaller andmore » more clusters are observed in the alloys. The vacancy diffusion occurs at relatively higher temperatures than interstitials, and their clustering leads to formation of stacking fault tetrahedra, also consistent with our experiments. The results also show that the surviving Frenkel pairs are composition-dependent and are largely Ni dominated.« less

Thermally Induced Interdiffusion and Precipitation in a Ni/Ni 3 Al System

DOE PAGES

Sun, C.; Martinez, E.; Aguiar, J. A.; ...

2015-05-20

Ordered Ni 3Al intermetallic precipitates constitute the main hardening sources of Ni-based superalloys. Here, we report the interdiffusion and precipitation behavior in a Ni/Ni3Al model system. The deposition of Ni3Al on a pure Ni layer at 500°C generated L12-structured γ' (Ni3Al) precipitates, preferentially at the interface. After annealing at 800°C for 1 h, interdiffusion between Ni and Ni3Al layers occurred, and the γ' precipitates that grew near the parent Ni/Ni 3Al interface are ~2.8 times larger in size than those formed in the matrix. In conclusion, Monte Carlo simulations indicate that vacancies preferentially diffuse along the Ni/Ni 3Al interface, increasingmore » the probability of precipitation.« less

Tai Chi Chuan: an ancient wisdom on exercise and health promotion.

PubMed

Lan, Ching; Lai, Jin-Shin; Chen, Ssu-Yuan

2002-01-01

Tai Chi Chuan (TCC) is a Chinese conditioning exercise and is well known for its slow and graceful movements. Recent investigations have found that TCC is beneficial to cardiorespiratory function, strength, balance, flexibility, microcirculation and psychological profile. The long-term practice of TCC can attenuate the age decline in physical function, and consequently it is a suitable exercise for the middle-aged and elderly individuals. TCC can be prescribed as an alternative exercise programme for selected patients with cardiovascular, orthopaedic, or neurological diseases, and can reduce the risk of falls in elderly individuals. The exercise intensity of TCC depends on training style, posture and duration. Participants can choose to perform a complete set of TCC or selected movements according to their needs. In conclusion, TCC has potential benefits in health promotion, and is appropriate for implementation in the community.

Determination of gaseous and particulate carbonyls (glycolaldehyde, hydroxyacetone, glyoxal, methylglyoxal, nonanal and decanal) in the atmosphere at Mt. Tai

NASA Astrophysics Data System (ADS)

Kawamura, K.; Okuzawa, K.; Aggarwal, S. G.; Irie, H.; Kanaya, Y.; Wang, Z.

2013-01-01

Gaseous and particulate semi-volatile carbonyl compounds were determined every three hours in the atmosphere of Mount Tai (elevation, 1534 m) in the North China Plain during 2-5, 23-24 and 25 June, 2006 under a clear sky condition. Using two-step filter cartridge in a series, particulate carbonyls were first collected on a quartz filter and then gaseous carbonyls were collected on a quartz filter impregnated with O-benzylhydroxylamine (BHA). After the two-step derivatization with BHA and N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA), carbonyl derivatives were measured using a gas chromatography. The gaseous concentrations were obtained as follow: glycolaldehyde (range 0-1271 ng m-3, average 555 ng m-3), hydroxyacetone (0-707 ng m-3, 163 ng m-3), glyoxal (198-1396 ng m-3, 720 ng m-3), methylglyoxal (410-3170 ng m-3, 1376 ng m-3), n-nonanal (0-236 ng m-3, 71 ng m-3), and n-decanal (0-159 ng m-3, 31 ng m-3). These concentrations are among the highest ever reported in the urban and forest atmosphere. We found that gaseous carbonyls are more than 10 times more abundant than particulate carbonyls. Time-resolved variations of carbonyls did not show any a clear diurnal pattern, except for hydroxyacetone. We found that glyoxal, methylglyoxal and glycolaldehyde positively correlated with levoglucosan (a tracer of biomass burning), suggesting that a contribution from field burning of agricultural wastes (wheat crops) is significant for the bifunctional carbonyls in the atmosphere of Mt. Tai. Upward transport of the pollutants to the mountaintop from the low lands in the North China Plain is a major process to control the distributions of carbonyls in the upper atmosphere over Mt. Tai.

A Threonine Stabilizes the NiC and NiR Catalytic Intermediates of [NiFe]-hydrogenase*

PubMed Central

Abou-Hamdan, Abbas; Ceccaldi, Pierre; Lebrette, Hugo; Gutiérrez-Sanz, Oscar; Richaud, Pierre; Cournac, Laurent; Guigliarelli, Bruno; De Lacey, Antonio L.; Léger, Christophe; Volbeda, Anne; Burlat, Bénédicte; Dementin, Sébastien

2015-01-01

The heterodimeric [NiFe] hydrogenase from Desulfovibrio fructosovorans catalyzes the reversible oxidation of H2 into protons and electrons. The catalytic intermediates have been attributed to forms of the active site (NiSI, NiR, and NiC) detected using spectroscopic methods under potentiometric but non-catalytic conditions. Here, we produced variants by replacing the conserved Thr-18 residue in the small subunit with Ser, Val, Gln, Gly, or Asp, and we analyzed the effects of these mutations on the kinetic (H2 oxidation, H2 production, and H/D exchange), spectroscopic (IR, EPR), and structural properties of the enzyme. The mutations disrupt the H-bond network in the crystals and have a strong effect on H2 oxidation and H2 production turnover rates. However, the absence of correlation between activity and rate of H/D exchange in the series of variants suggests that the alcoholic group of Thr-18 is not necessarily a proton relay. Instead, the correlation between H2 oxidation and production activity and the detection of the NiC species in reduced samples confirms that NiC is a catalytic intermediate and suggests that Thr-18 is important to stabilize the local protein structure of the active site ensuring fast NiSI-NiC-NiR interconversions during H2 oxidation/production. PMID:25666617

A threonine stabilizes the NiC and NiR catalytic intermediates of [NiFe]-hydrogenase.

PubMed

Abou-Hamdan, Abbas; Ceccaldi, Pierre; Lebrette, Hugo; Gutiérrez-Sanz, Oscar; Richaud, Pierre; Cournac, Laurent; Guigliarelli, Bruno; De Lacey, Antonio L; Léger, Christophe; Volbeda, Anne; Burlat, Bénédicte; Dementin, Sébastien

2015-03-27

The heterodimeric [NiFe] hydrogenase from Desulfovibrio fructosovorans catalyzes the reversible oxidation of H2 into protons and electrons. The catalytic intermediates have been attributed to forms of the active site (NiSI, NiR, and NiC) detected using spectroscopic methods under potentiometric but non-catalytic conditions. Here, we produced variants by replacing the conserved Thr-18 residue in the small subunit with Ser, Val, Gln, Gly, or Asp, and we analyzed the effects of these mutations on the kinetic (H2 oxidation, H2 production, and H/D exchange), spectroscopic (IR, EPR), and structural properties of the enzyme. The mutations disrupt the H-bond network in the crystals and have a strong effect on H2 oxidation and H2 production turnover rates. However, the absence of correlation between activity and rate of H/D exchange in the series of variants suggests that the alcoholic group of Thr-18 is not necessarily a proton relay. Instead, the correlation between H2 oxidation and production activity and the detection of the NiC species in reduced samples confirms that NiC is a catalytic intermediate and suggests that Thr-18 is important to stabilize the local protein structure of the active site ensuring fast NiSI-NiC-NiR interconversions during H2 oxidation/production. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Effects of Acupuncture, Tuina, Tai Chi, Qigong, and Traditional Chinese Medicine Five-Element Music Therapy on Symptom Management and Quality of Life for Cancer Patients: A Meta-Analysis.

PubMed

Tao, Wei-Wei; Jiang, Hua; Tao, Xiao-Mei; Jiang, Ping; Sha, Li-Yan; Sun, Xian-Ce

2016-04-01

Most cancer patients suffer from both the disease itself and symptoms induced by conventional treatment. Available literature on the clinical effects on cancer patients of acupuncture, Tuina, Tai Chi, Qigong, and Traditional Chinese Medicine Five-Element Music Therapy (TCM-FEMT) reports controversial results. The primary objective of this meta-analysis was to evaluate the effect of acupuncture, Tuina, Tai Chi, Qigong, and TCM-FEMT on various symptoms and quality of life (QOL) in patients with cancer; risk of bias for the selected trials also was assessed. Studies were identified by searching electronic databases (MEDLINE via both PubMed and Ovid, Cochrane Central, China National Knowledge Infrastructure, Chinese Scientific Journal Database, China Biology Medicine, and Wanfang Database). All randomized controlled trials (RCTs) using acupuncture, Tuina, Tai Chi, Qigong, or TCM-FEMT published before October 2, 2014, were selected, regardless of whether the article was published in Chinese or English. We identified 67 RCTs (5465 patients) that met our inclusion criteria to perform this meta-analysis. Analysis results showed that a significant combined effect was observed for QOL change in patients with terminal cancer in favor of acupuncture and Tuina (Cohen's d: 0.21-4.55, P < 0.05), whereas Tai Chi and Qigong had no effect on QOL of breast cancer survivors (P > 0.05). The meta-analysis also demonstrated that acupuncture produced small-to-large effects on adverse symptoms including pain, fatigue, sleep disturbance, and some gastrointestinal discomfort; however, no significant effect was found on the frequency of hot flashes (Cohen's d = -0.02; 95% CI = -1.49 to 1.45; P = 0.97; I(2) = 36%) and mood distress (P > 0.05). Tuina relieved gastrointestinal discomfort. TCM-FEMT lowered depression level. Tai Chi improved vital capacity of breast cancer patients. High risk of bias was present in 74.63% of the selected RCTs. Major sources of risk of bias were lack of blinding

Cyclic and isothermal oxidation behavior at 1100 and 1200 C of Ni-20Cr, Ni-20Cr-3Mn, Ni-20Cr-3Si, and Ni-40Cr alloys

NASA Technical Reports Server (NTRS)

Lowell, C. E.

1973-01-01

Alloys of Ni-20Cr, Ni-20Cr-3Mn, Ni-20Cr-3Si, and Ni-40Cr were cyclically oxidized at 1100 and 1200 C for up to 100 hours. Oxidation behavior was judged by sample thickness and weight change, metallography, diffraction, and microprobe analysis. The least attacked were Ni-40Cr and Ni-20Cr-3Si. The alloy Ni-20Cr-3Mn was much less attacked than Ni-20Cr, but more than the other alloys. The formation of Cr2O3 accounted for the increased resistance of Ni-Cr and Ni-20Cr-3Si, and the formation of MnCr2O4 accounts for the improvement in Ni-20Cr-3mn over Ni-20Cr.

Toward optimal soil organic carbon sequestration with effects of agricultural management practices and climate change in Tai-Lake paddy soils of China

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Liming; Zhuang, Qianlai; He, Yujie

Understanding the impacts of climate change and agricultural management practices on soil organic carbon (SOC) dynamics is critical for implementing optimal farming practices and maintaining agricultural productivity. This study examines the influence of climate and agricultural management on carbon sequestration potentials in Tai-Lake Paddy soils of China using the DeNitrification-DeComposition (DNDC) model, with a high-resolution soil database (1:50,000). Model simulations considered the effects of no tillage, increasing manure application, increasing/decreasing of N-fertilizer application and crop residues, water management, and climatic shifts in temperature and precipitation. We found that the carbon sequestration potential for the 2.32 Mha paddy soils of themore » Tai-Lake region varied from 4.71 to 44.31 Tg C during the period 2001-2019, with an annual average SOC changes ranged from 107 to 1005 kg C ha -1 yr -1. The sequestration potential significantly increased with increasing application of N-fertilizer, manure, conservation tillage, and crop residues. To increase soil C sequestration in this region, no-tillage and increasing of crop residue return to soils and manure application are recommended. Our analysis of climate impacts on SOC sequestration suggests that the rice paddies in this region will continue to be a carbon sink under future warming conditions. In addition, because the region’s annual precipitation (>1200 mm) is high, we also recommend reducing irrigation water use for these rice paddies to conserve freshwater in the Tai-Lake region.« less

Interdiffusion in the Ni/TD-NiCr and Cr/TD-NiCr systems

NASA Technical Reports Server (NTRS)

Pawar, A. V.; Tenney, D. R.

1974-01-01

The diffusion of Ni and Cr into TD-NiCr has been studied over the 900 to 1100 C temperature range. The diffusion couples were prepared by electroplating Cr and Ni on polished TD-NiCr wafers. Concentration profiles produced as a result of isothermal diffusion at 905, 1000, and 1100 C were determined by electron microprobe analysis. The Boltzmann-Matano analysis was used to determine concentration-dependent diffusion coefficients which were found to compare favorably with previously reported values. These data suggest that 2 vol % ThO2 distribution has no appreciable effect on the rates of diffusion in TD-NiCr with a large grain size. This supports the view that an inert dispersoid in an alloy matrix will not in itself lead to enhanced diffusion unless a short-circuit diffusion structure is stabilized.

The Effect of Metal Composition on Fe-Ni Partition Behavior between Olivine and FeNi-Metal, FeNi-Carbide, FeNi-Sulfide at Elevated Pressure

NASA Technical Reports Server (NTRS)

Holzheid, Astrid; Grove, Timothy L.

2005-01-01

Metal-olivine Fe-Ni exchange distribution coefficients were determined at 1500 C over the pressure range of 1 to 9 GPa for solid and liquid alloy compositions. The metal alloy composition was varied with respect to the Fe/Ni ratio and the amount of dissolved carbon and sulfur. The Fe/Ni ratio of the metal phase exercises an important control on the abundance of Ni in the olivine. The Ni abundance in the olivine decreases as the Fe/Ni ratio of the coexisting metal increases. The presence of carbon (up to approx. 3.5 wt.%) and sulfur (up to approx. 7.5 wt.%) in solution in the liquid Fe-Ni-metal phase has a minor effect on the partitioning of Fe and Ni between metal and olivine phases. No pressure dependence of the Fe-Ni-metal-olivine exchange behavior in carbon- and sulfur-free and carbon- and sulfur-containing systems was found within the investigated pressure range. To match the Ni abundance in terrestrial mantle olivine, assuming an equilibrium metal-olivine distribution, a sub-chondritic Fe/Ni-metal ratio that is a factor of 17 to 27 lower than the Fe/Ni ratios in estimated Earth core compositions would be required, implying higher Fe concentrations in the core forming metal phase. A simple metal-olivine equilibrium distribution does not seem to be feasible to explain the Ni abundances in the Earth's mantle. An equilibrium between metal and olivine does not exercise a control on the problem of Ni overabundance in the Earth's mantle. The experimental results do not contradict the presence of a magma ocean at the time of terrestrial core formation, if olivine was present in only minor amounts at the time of metal segregation.

Comparative effects of Yi Jin Jing versus Tai Chi exercise training on benign prostatic hyperplasia-related outcomes in older adults: study protocol for a randomized controlled trial.

PubMed

Liu, XiangYun; Huang, Guoyuan; Chen, Peijie; Li, Yong; Xiang, JiuLin; Chen, Ting; Wang, Ru

2016-07-16

Benign prostatic hyperplasia (BPH) and its associated lower urinary tract symptoms (LUTS) occur very commonly in older men. BPH and LUTS cause substantial physical and psychological impairment that could seriously affect the quality of late life and greatly cost the health-care systems. Current surgical and pharmacological therapies are expensive, may not effectively improve prostate function and health but cause adverse effects. There is an urgent need to find new and effective non-pharmacological preventions and treatments. Yi Jin Jing and Tai Chi are two common traditional Chinese mind-body exercises with different movements and techniques, but both emphasize regulating functional homeostasis and keeping whole body harmony. Yi Jin Jing and Tai Chi have not been studied much for potentially use in the treatment of BPH-related problems. The primary purpose of this protocol is to assess the effectiveness of Yi Jin Jing versus Tai Chi on the monographic and functional changes of prostate in older men. A prospective single-center randomized controlled trial will be conducted. A total of 150 old men (60-70 years old) will be recruited from the urban tertiary of Shanghai, China. Of these, 50 eligible participants will be randomly assigned to a control group and two intervention groups with either Yi Jin Jing or Tai Chi exercise training. They will undergo 30 minutes for each exercise for five times a week for 6 months. The primary outcomes are changes of signs and symptoms in BPH and lower urinary tract from baseline to post-intervention. The main secondary outcomes are exercise-induced effects on the circulating levels of estrogen and androgen. All the outcome measures will be assessed at baseline, immediately after the 6-month intervention, and at the 3-month post-intervention follow-up. This proposed study will be the first comparative randomized clinical trial to evaluate the effectiveness of Yi Jin Jing versus Tai Chi exercise on prostate health among older

Incorporation of Complex Hydrological and Socio-economic Factors for Non-point Source Pollution Control: A Case Study at the Yincungang Canal, the Lake Tai Basin of China

NASA Astrophysics Data System (ADS)

Yang, X.; Luo, X.; Zheng, Z.

2012-04-01

It is increasingly realized that non-point pollution sources contribute significantly to water environment deterioration in China. Compared to developed countries, non-point source pollution in China has the unique characteristics of strong intensity and composition complexity due to its special socioeconomic conditions. First, more than 50% of its 1.3 billion people are rural. Sewage from the majority of the rural households is discharged either without or only with minimal treatment. The large amount of erratic rural sewage discharge is a significant source of water pollution. Second, China is plagued with serious agricultural pollution due to widespread improper application of fertilizers and pesticides. Finally, there lack sufficient disposal and recycling of rural wastes such as livestock manure and crop straws. Pollutant loads from various sources have far exceeded environmental assimilation capacity in many parts of China. The Lake Tai basin is one typical example. Lake Tai is the third largest freshwater lake in China. The basin is located in the highly developed and densely populated Yangtze River Delta. While accounting for 0.4% of its land area and 2.9% of its population, the Lake Tai basin generates more than 14% of China's Gross Domestic Production (GDP), and the basin's GDP per capita is 3.5 times as much as the state average. Lake Tai is vital to the basin's socio-economic development, providing multiple services including water supply for municipal, industrial, and agricultural needs, navigation, flood control, fishery, and tourism. Unfortunately, accompanied with the fast economic development is serious water environment deterioration in the Lake Tai basin. The lake is becoming increasingly eutrophied and has frequently suffered from cyanobacterial blooms in recent decades. Chinese government has made tremendous investment in order to mitigate water pollution conditions in the basin. Nevertheless, the trend of deteriorating water quality has yet to

On the nature of Ni···Ni interaction in a model dimeric Ni complex.

PubMed

Kamiński, Radosław; Herbaczyńska, Beata; Srebro, Monika; Pietrzykowski, Antoni; Michalak, Artur; Jerzykiewicz, Lucjan B; Woźniak, Krzysztof

2011-06-07

A new dinuclear complex (NiC(5)H(4)SiMe(2)CHCH(2))(2) (2) was prepared by reacting nickelocene derivative [(C(5)H(4)SiMe(2)CH=CH(2))(2)Ni] (1) with methyllithium (MeLi). Good quality crystals were subjected to a high-resolution X-ray measurement. Subsequent multipole refinement yielded accurate description of electron density distribution. Detailed inspection of experimental electron density in Ni···Ni contact revealed that the nickel atoms are bonded and significant deformation of the metal valence shell is related to different populations of the d-orbitals. The existence of the Ni···Ni bond path explains the lack of unpaired electrons in the complex due to a possible exchange channel.

Nickel (Ni) allergic patients with complications to Ni containing joint replacement show preferential IL-17 type reactivity to Ni.

PubMed

Summer, Burkhard; Paul, Carina; Mazoochian, Farhad; Rau, Christoph; Thomsen, Marc; Banke, Ingo; Gollwitzer, Hans; Dietrich, Karin-Almut; Mayer-Wagner, Susanne; Ruzicka, Thomas; Thomas, Peter

2010-07-01

Some nickel (Ni) allergic patients develop complications following Ni-containing arthroplasty. In the peri-implant tissue of such patients, we had observed lymphocyte dominated inflammation together with IFN-gamma and IL-17 expression. To determine whether Ni stimulation of peripheral blood mononuclear cells (PBMCs) of such patients would lead to a different cytokine pattern as compared to Ni-allergic patients with symptom-free arthroplasty. Based on history and patch testing in 15 Ni-allergic patients (five without implant, five with symptom-free arthroplasty, five with complicated arthroplasty) and five non-allergic individuals, lymphocyte transformation test (LTT) was performed using PBMC. In parallel in vitro cytokine response to Ni was assessed by real-time reverse transcriptase-polymerase chain reaction (RT-PCR). All 15 Ni-allergic individuals showed enhanced LTT reactivity to Ni (mean SI = 8.42 +/- 1.8) compared to the non-allergic control group. Predominant IFN-gamma expression to Ni was found both in the five allergic patients without arthroplasty and also in the five allergic, symptom-free arthroplasty patients. In contrast, in the five Ni-allergic patients with arthroplasty-linked complications a predominant, significant IL-17 expression to Ni was seen but not in patients with symptom-free arthroplasty. The predominant IL-17 type response to Ni may characterize a subgroup of Ni-allergic patients prone to develop lymphocytic peri-implant hyper-reactivity.

The Ni-rich part of the Al–Ge–Ni phase diagram

PubMed Central

Jandl, Isabella; Reichmann, Thomas L.; Richter, Klaus W.

2013-01-01

The Ni-rich part of the ternary system Al–Ge–Ni (xNi > 50 at.%) was investigated by means of optical microscopy, powder X-ray diffraction (XRD), differential thermal analysis (DTA) and scanning electron microscopy (SEM). The two isothermal sections at 550 °C and 700 °C were determined. Within these two sections a new ternary phase, designated as τ4, AlyGe9−yNi13±x (hP66, Ga3Ge6Ni13-type) was detected and investigated by single crystal X-ray diffraction. Another ternary low temperature phase, τ5, was found only in the isothermal section at 550 °C around the composition AlGeNi4. This compound was found to crystallise in the Co2Si type structure (oP12, Pnma). The structure was identified by Rietveld refinement of powder data. The NiAs type (B8) phase based on binary Ge3Ni5 revealed an extended solid solubility of Al and the two isotypic compounds AlNi3 and GeNi3 form a complete solid solution. Based on DTA results, six vertical sections at 55, 60, 70, 75 and 80 at.% Ni and at a constant Al:Ni ratio of 1:3 were constructed. Furthermore, the liquidus surface projection and the reaction scheme (Scheil diagram) were completed by combining our results with previous results from the Ni-poor part of the phase diagram. Six invariant ternary reactions were identified in the Ni-rich part of the system. PMID:27087754

Kinetics of Ni2Si growth from pure Ni and Ni(V) films on (111) and (100) Si

NASA Astrophysics Data System (ADS)

Harith, M. A.; Zhang, J. P.; Campisano, S. U.; Klaar, H.-J.

1987-01-01

The kinetics of Ni2Si growth from pure Ni and from Ni0.93V0.07 films on (111) and (100) silicon has been studied by the combination of He+ backscattering, x-ray diffraction, Auger electron spectroscopy (AES) and transmission electron microscopy (TEM) techniques. The activation energies are 1.5 and 1.0 eV for pure Ni and Ni(V) films, respectively while the pre-exponential factors in Ni(V) are 4 5 orders of magnitude smaller than in the pure Ni case. The variations in the measured rates are related to the different grain size of the growing suicide layers. The vanadium is rejected from the silicide layer and piles up at the metalsilicide interface.

Tuning Ni-catalyzed CO 2 hydrogenation selectivity via Ni-ceria support interactions and Ni-Fe bimetallic formation

DOE PAGES

Winter, Lea R.; Gomez, Elaine; Yan, Binhang; ...

2017-10-16

CO 2 hydrogenation over Fe-modified Ni/CeO 2 catalysts was investigated in a batch reactor using time-resolved in situ FTIR spectroscopy. Low loading of Ni/CeO 2 was associated with high selectivity to CO over CH 4, while higher Ni loading improved CO 2 hydrogenation activity with a reduced CO selectivity. X-ray absorption near-edge structure (XANES) analysis revealed Ni to be metallic for all catalysts including the CO-selective low loading 0.5% Ni catalyst, suggesting that the selectivity trend is due to structural rather than oxidation state effects. The loading amount of 1.5% Ni was selected for co-impregnation with Fe, based on themore » significant shift in product selectivity towards CH 4 for that loading amount, in order to shift the selectivity towards CO while maintaining high activity. Temperature programmed reduction (TPR) results indicated bimetallic interactions between Ni and Fe, and XANES analysis showed that about 70% of Fe in the bimetallic catalysts was oxidized. The Ni-Fe catalysts demonstrated improved selectivity towards CO without significantly compromising activity, coupling the high activity of Ni catalysts and the high CO selectivity of Fe. The general trends in Ni loading and bimetallic modification should guide efforts to develop non-precious metal catalysts for the selective production of CO by CO 2 hydrogenation.« less

Walker Circulation, El Niño and La Niña

NASA Astrophysics Data System (ADS)

Halpern, D.

2014-12-01

Ocean surface wind vector is likely the critical variable to predict onset, maintenance and dissipation of El Niño and La Niña. Analyses of SeaWinds and ASCAT 10-m height (called "surface") vector winds in the Atlantic, Indian and Pacific Oceans from 1°S-1°N during March 2000 - June 2011 revealed the longitudinal distribution of the surface zonal wind component associated with the Walker Circulation. In the Pacific Ocean east of 140°E and west of 85°W, the mean wind direction was westward towards the maritime continent with maximum mean zonal wind speed (- 6.5 m s-1) at 150°W; east of 85°W the mean direction was toward the convection zone over South America. Four El Niños and five La Niñas occurred from March 2000 - June 2011. In the Pacific from 150°E to 160°W, the average El Niño (La Niña) westward wind speed was 2 m s-1 (1 m s-1) smaller (larger) than normal. In the west Pacific, the variation in westward wind speeds in El Niño and La Niña conditions relative to normal conditions would be expected to substantially uplift the thermocline during El Niño compared to La Niña, which is consistent with conventional wisdom. In the east Pacific from 130°W - 100°W, average El Niño westward wind speeds were less than normal and La Niña conditions by 0.5 m s-1 and 1 m s-1, respectively. The "central" Pacific nature of the El Niños may have influenced the smaller difference between El Niño and La Niña westward wind speeds in the east Pacific compared to the west Pacific. Analyses of longitudinal distributions of thermocline depths will be discussed. Surface zonal wind speeds in the Atlantic and Indian Oceans showed no evidence of El Niño and La Niña; surface meridional winds showed an apparent response in the Indian and Pacific Oceans but not in the Atlantic Ocean. At 700-m height, the MISR zonal wind component in the Atlantic, Indian and Pacific Oceans had similar features as those at the surface, except in the east Pacific where the westward

Ni-NiO core-shell inverse opal electrodes for supercapacitors.

PubMed

Kim, Jae-Hun; Kang, Soon Hyung; Zhu, Kai; Kim, Jin Young; Neale, Nathan R; Frank, Arthur J

2011-05-14

A general template-assisted electrochemical approach was used to synthesize three-dimensional ordered Ni core-NiO shell inverse opals (IOs) as electrodes for supercapacitors. The Ni-NiO IO electrodes displayed pseudo-capacitor behavior, good rate capability and cycling performance. © The Royal Society of Chemistry 2011

Effects of a 12-week program of Tai Chi exercise on the kidney disease quality of life and physical functioning of patients with end-stage renal disease on hemodialysis.

PubMed

Chang, Jo-Han; Koo, Malcolm; Wu, Sheng-Wen; Chen, Chiu-Yuan

2017-02-01

Previous studies have shown that exercise training in patients with end-stage renal disease could improve their physical functioning and quality of life. Nevertheless, few studies have evaluated the effects of Tai Chi exercise in patients on hemodialysis. To investigate the effects of a Tai Chi exercise intervention on the quality of life and physical functioning in end-stage renal disease patients on hemodialysis. A pre-post experimental design. Patients, aged 20 years or older, on hemodialysis recruited from the hemodialysis unit at a medical center in central Taiwan were assigned, based on their own preference, to either a control group (n=25) or an intervention group (n=21). A weekly one-hour short-form Yang style Tai Chi session for a total of 12 weeks. Physical functioning and Kidney Disease Quality of Life (KDQOL) at the baseline and at the end of the intervention. The least square means of repetition of sit-to-stand cycles in one minute (STS-60), 6-min walk test, and gait speed test were significantly improved in the intervention group. In addition, the least square means of the five different dimensions of the KDQOL were all significantly higher in the intervention group, except the SF-12 physical health score. Improvements in the kidney disease quality of life and physical functioning were observed in Taiwanese patients on hemodialysis with a 12-week Tai Chi exercise intervention. Copyright © 2016. Published by Elsevier Ltd.

An Ultrastable and High-Performance Flexible Fiber-Shaped Ni-Zn Battery based on a Ni-NiO Heterostructured Nanosheet Cathode.

PubMed

Zeng, Yinxiang; Meng, Yue; Lai, Zhengzhe; Zhang, Xiyue; Yu, Minghao; Fang, Pingping; Wu, Mingmei; Tong, Yexiang; Lu, Xihong

2017-11-01

Currently, the main bottleneck for the widespread application of Ni-Zn batteries is their poor cycling stability as a result of the irreversibility of the Ni-based cathode and dendrite formation of the Zn anode during the charging-discharging processes. Herein, a highly rechargeable, flexible, fiber-shaped Ni-Zn battery with impressive electrochemical performance is rationally demonstrated by employing Ni-NiO heterostructured nanosheets as the cathode. Benefiting from the improved conductivity and enhanced electroactivity of the Ni-NiO heterojunction nanosheet cathode, the as-fabricated fiber-shaped Ni-NiO//Zn battery displays high capacity and admirable rate capability. More importantly, this Ni-NiO//Zn battery shows unprecedented cyclic durability both in aqueous (96.6% capacity retention after 10 000 cycles) and polymer (almost no capacity attenuation after 10 000 cycles at 22.2 A g -1 ) electrolytes. Moreover, a peak energy density of 6.6 µWh cm -2 , together with a remarkable power density of 20.2 mW cm -2 , is achieved by the flexible quasi-solid-state fiber-shaped Ni-NiO//Zn battery, outperforming most reported fiber-shaped energy-storage devices. Such a novel concept of a fiber-shaped Ni-Zn battery with impressive stability will greatly enrich the flexible energy-storage technologies for future portable/wearable electronic applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Feasibility and effects of TAI CHI for the promotion of sleep quality and quality of life: a single-group study in a sample of older Chinese individuals in Hong Kong.

PubMed

Lo, Catherine Mei-Han; Lee, Paul H

2014-03-01

Poor sleep in later life is a global issue that reduces many individuals' quality of life (QOL). The purpose of this pilot study was to test the feasibility and effects of a simplified tai chi exercise intervention on sleep quality and QOL among Chinese community-dwelling older adults with poor sleep quality. This single-group, descriptive feasibility study included 34 individuals with poor sleep quality who agreed to participate in a 12-week tai chi intervention. Twenty-six individuals completed the program (23.5% dropout rate). Older adults with poor sleep quality who completed the intervention showed significant improvement in the Medical Outcomes Study Short Form-36 mental component and the Pittsburgh Sleep Quality Index global and component scores. The low recruitment and attendance and high dropout rates might be associated with participants' age, gender, and sleep quality. Further long-term studies are required to examine the potential effects of the tai chi intervention. [Journal of Gerontological Nursing, 40(3), 46-52.]. Copyright 2014, SLACK Incorporated.

Porous NiTi shape memory alloys produced by SHS: microstructure and biocompatibility in comparison with Ti2Ni and TiNi3.

PubMed

Bassani, Paola; Panseri, Silvia; Ruffini, Andrea; Montesi, Monica; Ghetti, Martina; Zanotti, Claudio; Tampieri, Anna; Tuissi, Ausonio

2014-10-01

Shape memory alloys based on NiTi have found their main applications in manufacturing of new biomedical devices mainly in surgery tools, stents and orthopedics. Porous NiTi can exhibit an engineering elastic modulus comparable to that of cortical bone (12-17 GPa). This condition, combined with proper pore size, allows good osteointegration. Open cells porous NiTi was produced by self propagating high temperature synthesis (SHS), starting from Ni and Ti mixed powders. The main NiTi phase is formed during SHS together with other Ni-Ti compounds. The biocompatibility of such material was investigated by single culture experiment and ionic release on small specimen. In particular, NiTi and porous NiTi were evaluated together with elemental Ti and Ni reference metals and the two intermetallic TiNi3, Ti2Ni phases. This approach permitted to clearly identify the influence of secondary phases in porous NiTi materials and relation with Ni-ion release. The results indicated, apart the well-known high toxicity of Ni, also toxicity of TiNi3, whilst phases with higher Ti content showed high biocompatibility. A slightly reduced biocompatibility of porous NiTi was ascribed to combined effect of TiNi3 presence and topography that requires higher effort for the cells to adapt to the surface.

Synthesis and synchrotron X-ray characterization of two 2D Hoffman related compounds [Ni(p-Xylylenediamine)nNi(CN)4] and [Ni(p-tetrafluoroxylylenediamine)nNi(CN)4

NASA Astrophysics Data System (ADS)

Wong-Ng, W.; Culp, J. T.; Siderius, D. W.; Chen, Y. S.

2018-07-01

Synchrotron X-ray single crystal structure determination of two 2D Hofmann-related compounds, [Ni(p-Xylyenediamine)n-tetracyanonickelate] (abbreviated as Ni-pXdam) and [Ni(tetrafluoro-p-Xylyenediamine)n-tetracyanonickelate] (abbreviated as Ni-pXdamF4), have been conducted. Both the pXdam and pXdamF4 ligands contain two short chains of -CH2NH2 at the para-positions of a phenyl ring. These flexible chains link the 6-fold coordinated Ni2 sites throughout the network. In Ni-pXdam, the closed-2D network of [Ni-(CN-Ni1/4-)4]∞ is broken into 1D chains, leaving the C≡N groups at the trans-positions of the Ni(CN)4 moiety unbridged. The resulting 1D chains [(trans-)-NC-Ni(CN)2-CN-Ni-]∞ runs along the [010] direction of the unit cell. The pXdam ligands bridge in pair between the Ni atoms of the adjacent chains. The catenation structure of [Ni{(pXdam)}]∞ could be referred to as double -1D. In Ni-pXdamF4, the -CH2NH2 ligands connect the neighboring chains via the 6-fold Ni2 site. Surrounding the 4-fold Ni1 site, the two trans terminal C≡N groups were replaced by the Lewis base NH3 during the synthesis process, therefore preventing the propagation of the 2D net to form a 3D network. Computed pore volume of both compounds indicated that there is not sufficient space in the structure to accommodate gas molecules. In both compounds, hydrogen bonds were found, and solvent of crystallization was absent due to the limited free space in the structure.

On the similarity of the bonding in NiS and NiO

NASA Technical Reports Server (NTRS)

Bauschlicher, C. W., Jr.

1985-01-01

The bonding in NiS is found to be quite similar to that in NiO, having an ionic contribution arising from the donation of the Ni 4s electron to the S atom and a covalent component arising from bonds between the Ni 3d and the S 3p. The one-electron d bonds are found to be of equal strength for NiO and NiS, but the two-electron d bonds are weaker for NiS.

Effects of Tai Chi exercise on blood pressure and plasma levels of nitric oxide, carbon monoxide and hydrogen sulfide in real-world patients with essential hypertension.

PubMed

Pan, Xiaogui; Zhang, Yi; Tao, Sai

2015-01-01

Objective was to investigate the effects of Tai Chi exercise on nitric oxide (NO), carbon monoxide (CO) and hydrogen sulfide (H2S) levels, and blood pressure (BP) in patients with essential hypertension (EH). EH patients were assigned to the Tai Chi exercise group (HTC, n = 24), and hypertension group (HP, n = 16) by patients' willingness. Healthy volunteers matched for age and gender were recruited as control (NP, n = 16). HTC group performed Tai Chi (60 min/d, 6 d/week) for 12 weeks. Measurements (blood glucose, cholesterol, NO, CO, H2S and BP) were obtained at week 0, 6, and 12. SBP, MAP, and low-density lipoprotein cholesterol levels decreased, and high-density lipoprotein cholesterol levels increased by week 12 in the HTC group (all p < 0.05 versus baseline). Plasma NO, CO, and H2S levels in the HTC group were increased after 12 weeks (all p < 0.05 versus baseline). SBP, DBP and MAP levels were significantly lower in the HTC than in the HP group (all p < 0.05). However, no changes were observed in the HP and NP groups. Correlations were observed between changes in SBP and changes in NO, CO and H2S (r = -0.45, -0.51 and -0.46, respectively, all p < 0.05), and between changes in MAP and changes in NO, CO and H2S (r = -0.36, -0.45 and -0.42, respectively, all p < 0.05). In conclusion, Tai Chi exercise seems to have beneficial effects on BP and gaseous signaling molecules in EH patients. However, further investigation is required to understand the exact mechanisms underlying these observations, and to confirm these results in a larger cohort.

Measurement of 59Ni and 63Ni by accelerator mass spectrometry at CIAE

NASA Astrophysics Data System (ADS)

Wang, Xiaoming; He, Ming; Ruan, Xiangdong; Xu, Yongning; Shen, Hongtao; Du, Liang; Xiao, Caijin; Dong, Kejun; Jiang, Shan; Yang, Xuran; Lan, Xiaoxi; Wu, Shaoyong; Zhao, Qingzhang; Cai, Li; Pang, Fangfang

2015-10-01

The long lived isotopes 59Ni and 63Ni can be used in many areas such as radioactive waste management, neutron dosimetry, cosmic radiation study, and so on. Based on the large accelerator and a big Q3D magnetic spectrometer, the measurement method for 59Ni and 63Ni is under development at the AMS facility at China Institute of Atomic Energy (CIAE). By using the ΔE-Q3D technique with the Q3D magnetic spectrometer, the isobaric interferences were greatly reduced in the measurements of 59Ni and 63Ni. A four anode gas ionization chamber was then used to further identify isobars. With these techniques, the abundance sensitivities of 59Ni and 63Ni measurements are determined as 59Ni/Ni = 1 × 10-13 and 63Ni/Ni = 2 × 10-12, respectively.

Morphology controlled synthesis of 2-D Ni-Ni3S2 and Ni3S2 nanostructures on Ni foam towards oxygen evolution reaction

NASA Astrophysics Data System (ADS)

Chaudhari, Nitin Kaduba; Oh, Aram; Sa, Young Jin; Jin, Haneul; Baik, Hionsuck; Kim, Sang Gu; Lee, Suk Joong; Joo, Sang Hoon; Lee, Kwangyeol

2017-03-01

Catalysts for oxygen evolution reactions (OER) are at the heart of key renewable energy technologies, and development of non-precious metal catalysts with high activity and stability remain a great challenge in this field. Among various material candidates, metal sulfides are receiving increasing attention. While morphology-dependent catalytic performances are well established in noble metal-based catalysts, relatively little is known for the morphology‒catalytic performance relationship in metal sulfide catalysts. In this study, uniform spider web-like Ni nanosheets-Ni3S2 and honeycomb-like Ni3S2 structures are deposited on nickel foam (Ni3S2/NF) by a facile one-step hydrothermal synthetic route. When used as an oxygen evolution electrode, the spider web-like Ni-Ni3S2/NF with the large exposed surface area shown excellent catalytic activity and stability with an overpotential of 310 mV to achieve at 10 mA/cm2 and a Tafel slope of 63 mV/dec in alkaline media, which is superior to the honeycomb-like structure without Ni nanosheet. The low Tafel slope of the spider web-like Ni-Ni3S2/NF represents one of the best OER kinetics among nickel sulfide-based OER catalysts. The results point to the fact that performance of the metal sulfide electrocatalysts might be fine-tuned and optimized with morphological controls.

Organic molecular compositions and temporal variations of summertime mountain aerosols over Mt. Tai, North China Plain

NASA Astrophysics Data System (ADS)

Fu, Pingqing; Kawamura, Kimitaka; Okuzawa, Kazuhiro; Aggarwal, Shankar Gopala; Wang, Gehui; Kanaya, Yugo; Wang, Zifa

2008-10-01

Total suspended particles (TSP) were collected at the summit of Mt. Tai (1534 m above sea level) on a daytime and nighttime basis during a summertime campaign (May-June 2006) and were characterized for organic molecular compositions using solvent extraction/derivatization and gas chromatography/mass spectrometry technique. The n-Alkanes, fatty acids, fatty alcohols, sugars, glycerol and polyacids, and phthalate esters were found as major organic compound classes, whereas lignin and resin products, sterols, aromatic acids, hopanes, and polycyclic aromatic hydrocarbons (PAHs) were detected as minor classes. Sugars (49.8-2115 ng m-3, average 640 ng m-3 in daytime; 18.1-4348 ng m-3, 799 ng m-3 in nighttime) were found to be the dominant compound class. Levoglucosan, a specific cellulose pyrolysis product, was detected as the most abundant single compound, followed by C28 fatty alcohol, diisobutyl and di-n-butyl phthalates, C29n-alkane, C16 and C28 fatty acids, and malic acid. By grouping organic compounds based on their sources, we found that emission of terrestrial plant waxes was the most significant source (30-34%) of the TSP, followed by biomass burning products (25-27%) (e.g., levoglucosan and lignin and resin products), soil resuspension (15-18%) due to agricultural activities, secondary oxidation products (8-10%), plastic emission (3-10%), marine/microbial sources (6%), and urban/industrial emissions from fossil fuel use (4%). However, low molecular weight dicarboxylic acids (such as oxalic acid) of photochemical origin were not included in this study. Malic acid was found to be much higher than those reported in the ground level, suggesting an enhanced photochemical production in the free troposphere over mountain areas. Temporal variations of biomass burning tracers (e.g., levoglucosan, galactosan, mannosan) and some higher plant wax derived compound classes suggested that there were two major (E1 and E2) and one minor (E3) biomass-burning events during this

Predictability of the Ningaloo Niño/Niña

PubMed Central

Doi, Takeshi; Behera, Swadhin K.; Yamagata, Toshio

2013-01-01

The seasonal prediction of the coastal oceanic warm event off West Australia, recently named the Ningaloo Niño, is explored by use of a state-of-the-art ocean-atmosphere coupled general circulation model. The Ningaloo Niño/Niña, which generally matures in austral summer, is found to be predictable two seasons ahead. In particular, the unprecedented extreme warm event in February 2011 was successfully predicted 9 months in advance. The successful prediction of the Ningaloo Niño is mainly due to the high prediction skill of La Niña in the Pacific. However, the model deficiency to underestimate its early evolution and peak amplitude needs to be improved. Since the Ningaloo Niño/Niña has potential impacts on regional societies and industries through extreme events, the present success of its prediction may encourage development of its early warning system. PMID:24100593

Charge ordering in Ni 1 + / Ni 2 + nickelates: La 4 Ni 3 O 8 and La 3 Ni 2 O 6

DOE PAGES

Botana, Antia S.; Pardo, Victor; Pickett, Warren E.; ...

2016-08-09

Ab initio calculations allow us to establish a close connection between the Ruddlesden-Popper layered nickelates and cuprates not only in terms of filling of d levels (close to d 9) but also because they show Ni 1+(S = 1/2)/Ni 2+(S = 0) stripe ordering. We obtained the insulating charge-ordered ground state from a combination of structural distortions and magnetic order. The Ni 2+ ions are in a low-spin configuration (S = 0) yielding an antiferromagnetic arrangement of Ni 1+ S = 1/2 ions like the long-sought spin-1/2 antiferromagnetic insulator analog of the cuprate parent materials. Furthermore, the analogy extends further with the main contribution to the bands near the Fermi energy coming from hybridized Ni d more » $$_x$$ 2- $$_y$$ 2 and O $p$ states.« less

Ferromagnetic resonance investigation in as-prepared NiFe/FeMn/NiFe trilayer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuan, S. J.; Xu, K.; Yu, L. M.

2007-06-01

NiFe/FeMn/NiFe trilayer prepared by dc magnetron sputtering was systematically investigated by ferromagnetic resonance technique (FMR) at room temperature. For NiFe/FeMn/NiFe trilayer, there are two distinct resonance peaks both in in-plane and out-of-plane FMR spectra, which are attributed to the two NiFe layers, respectively. The isotropic in-plane resonance field shift is negative for the bottom NiFe layer, while positive for the top NiFe layer. And, such phenomena result from the negative interfacial perpendicular anisotropy at the bottom NiFe/FeMn interface and positive interfacial perpendicular anisotropy at the top FeMn/NiFe interface. The linewidth of the bottom NiFe layer is larger than that ofmore » the top NiFe layer, which might be related to the greater exchange coupling at the bottom NiFe/FeMn interface.« less

Ni Foam-Ni3 S2 @Ni(OH)2 -Graphene Sandwich Structure Electrode Materials: Facile Synthesis and High Supercapacitor Performance.

PubMed

Wang, Xiaobing; Hu, Jiangjiang; Su, Yichang; Hao, Jin; Liu, Fanggang; Han, Shuang; An, Jian; Lian, Jianshe

2017-03-23

A novel Ni foam-Ni 3 S 2 @Ni(OH) 2 -graphene sandwich-structured electrode (NF-NN-G) with high areal mass loading (8.33 mg cm -2 ) has been developed by sulfidation and hydrolysis reactions. The conductivity of Ni 3 S 2 and Ni(OH) 2 were both improved. The upper layer of Ni(OH) 2 , covered with a thin graphene film, is formed in situ from the surface of the lower layer of Ni 3 S 2 , whereas the Ni 3 S 2 grown on Ni foam substrate mainly acts as a rough support bridging the Ni(OH) 2 and Ni foam. The graphene stabilized the Ni(OH) 2 and the electrochemical properties were effectively enhanced. The as-synthesized NF-NN-G-5mg electrode shows a high specific capacitance (2258 F g -1 at 1 A g -1 or 18.81 F cm -2 at 8.33 mA cm -2 ) and an outstanding rate property (1010 F g -1 at 20 Ag -1 or 8.413 F cm -2 at 166.6 mA cm -2 ). This result is around double the capacitance achieved in previous research on Ni 3 S 2 @Ni(OH) 2 /3DGN composites (3DGN=three-dimensional graphene network). In addition, the as-fabricated NF-NN-G-5mg composite electrode has an excellent cycle life with no capacitance loss after 3000 cycles, indicating a potential application as an efficient electrode. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Determination of gaseous and particulate carbonyls (glycolaldehyde, hydroxyacetone, glyoxal, methylglyoxal, nonanal and decanal) in the atmosphere at Mt. Tai

NASA Astrophysics Data System (ADS)

Kawamura, K.; Okuzawa, K.; Aggarwal, S. G.; Irie, H.; Kanaya, Y.; Wang, Z.

2013-05-01

Gaseous and particulate semi-volatile carbonyl compounds were determined every three hours in the atmosphere of Mount Tai (elevation, 1534 m) in the North China Plain during 2-5, 23-24 and 25 June 2006 under clear sky conditions. Using a two-step filter cartridge in a series, particulate carbonyls were first collected on a quartz filter and then gaseous carbonyls were collected on a quartz filter impregnated with O-benzylhydroxylamine (BHA). After the two-step derivatization with BHA and N,O-Bis(trimethylsilyl)trifluoroacetamide (BSTFA), carbonyl derivatives were measured using a gas chromatography. The gaseous concentrations were obtained as follow: glycolaldehyde (range 0-826 ng m-3, average 303 ng m-3), hydroxyacetone (0-579 ng m-3, 126 ng m-3), glyoxal (46-1200 ng m-3, 487 ng m-3), methylglyoxal (88-2690 ng m-3, 967 ng m-3), n-nonanal (0-500 ng m-3, 89 ng m-3), and n-decanal (0-230 ng m-3, 39 ng m-3). These concentrations are among the highest ever reported in the urban and forest atmosphere. We found that gaseous α-dicarbonyls (glyoxal and methylglyoxal) are more than 20 times more abundant than particulate carbonyls and that glycolaldehyde is one order of magnitude more abundant than in aerosol phase. In contrast, hydroxyacetone and normal aldehydes (nonanal and decanal) are equally present in both phases. Time-resolved variations of carbonyls did not show any a clear diurnal pattern, except for hydroxyacetone. We found that glyoxal, methylglyoxal and glycolaldehyde positively correlated with levoglucosan (a tracer of biomass burning), suggesting that a contribution from field burning of agricultural wastes (wheat crops) is significant for the bifunctional carbonyls in the atmosphere of Mt. Tai. Upward transport of the pollutants to the mountaintop from the low lands in the North China Plain is a major process to control the distributions of carbonyls in the upper atmosphere over Mt. Tai.

Fabrication of ordered Fe–Ni nitride film with equiatomic Fe/Ni ratio

NASA Astrophysics Data System (ADS)

Takata, Fumiya; Ito, Keita; Suemasu, Takashi

2018-05-01

We successfully grew a single-phase tetragonal FeNiN film with an equiatomic ratio of Fe, Ni, and N on a MgO(001) substrate by molecular beam epitaxy. We then demonstrated the formation of Fe2Ni2N films by extracting N atoms from the FeNiN film. These results suggested that Fe and Ni atoms in the Fe2Ni2N film were L10-ordered along the film plane direction because of the a-axis orientation growth of the FeNiN film on the MgO(001) substrate.

Effects of a T'ai Chi-Based Health Promotion Program on Metabolic Syndrome Markers, Health Behaviors, and Quality of Life in Middle-Aged Male Office Workers: A Randomized Trial.

PubMed

Choi, Ye-Sook; Song, Rhayun; Ku, Bon Jeong

2017-12-01

To determine the effects of a t'ai chi-applied worksite health promotion program on metabolic syndrome markers, health behaviors, and quality of life in middle-aged male office workers at a high risk of metabolic syndrome. A prospective randomized controlled study. Health center of a government office building in Korea. Forty-three male office workers with two or more metabolic syndrome markers. The office workers were randomly assigned either to an experimental group that received t'ai chi combined with health education twice weekly for 12 weeks, or to a control group that received health education only. Blood sampling for metabolic syndrome markers and structured questionnaires for health behaviors and quality of life. The experimental group showed significant reductions in systolic (t = -3.103, p = 0.003) and diastolic (t = -2.159, p = 0.037) blood pressures and the triglyceride level (t = -2.451, p = 0.019) compared with the control group. Those in the experimental group also performed health behaviors more frequently (t = 4.047, p < 0.001) and reported a significantly better quality of life (t = 3.193, p = 0.003) than those in the control group. The study findings show that t'ai chi was an effective adjunctive intervention in a worksite health promotion program for middle-aged office workers at a high risk of metabolic syndrome. Future studies should examine the long-term effects of t'ai chi-applied worksite health promotion programs in individuals with confirmed metabolic syndrome.

Preparation and characterization of Ni-P/Ni3.1B composite alloy coatings

NASA Astrophysics Data System (ADS)

Wang, Yurong; He, Jiawei; Wang, Wenchang; Shi, Jianhua; Mitsuzaki, Naotoshi; Chen, Zhidong

2014-02-01

The preparation of Ni-P/Ni3.1B composite alloy coating on the surface of copper was achieved by co-deposition of Ni3.1B nanoparticles with Ni-P coating during electroless plating. Ni-P-B alloy coating was obtained by heat-treating the as-plated Ni-P/Ni3.1B composite coating. The effect of the concentration of sodium alginate, borax, thiourea, Ni3.1B, temperature, and pH value on the deposition rate and B content were investigated and determined to be: 30 g L-1, 10 g L-1, 2 mg L-1, 20 mg L-1, 70 °C and 9.0 , respectively. Sodium alginate and thiourea were played as surfactant for coating Ni3.1B nanoparticles and stabilizer for the plating bath, respectively. Ni-P/Ni3.1B composite coating had good performance such as corrosion resistance and solderability.

Asymmetrical interfacial reactions of Ni/SAC101(NiIn)/Ni solder joint induced by current stressing

NASA Astrophysics Data System (ADS)

Lin, Chen-Yi; Chiu, Tsung-Chieh; Lin, Kwang-Lung

2018-03-01

An electric current can asymmetrically trigger either atomic migration or interfacial reactions between a cathode and an anode. The present study investigated the dissolution of metallization and formation of an interfacial intermetallic compound (IMC) in the Cu/Ni/Sn1.0Ag0.1Cu0.02Ni0.05In/Ni/Cu solder joint at various current densities in the order of 103 A/cm2 at temperatures ranging from 100 °C to 150 °C. The polarization behavior of Ni dissolution and IMC formation under current stressing were systematically investigated. The asymmetrical interfacial reactions of the solder joint were found to be greatly influenced by ambient temperature. The dissolution of Ni and its effect on interfacial IMC formation were also discussed.

Synthesis and catalytic performance of SiO2@Ni and hollow Ni microspheres

NASA Astrophysics Data System (ADS)

Liu, Xin; Liu, Yanhua; Shi, Xueting; Yu, Zhengyang; Feng, Libang

2016-11-01

Nickel (Ni) catalyst has been widely used in catalytic reducing reactions such as catalytic hydrogenation of organic compounds and catalytic reduction of organic dyes. However, the catalytic efficiency of pure Ni is low. In order to improve the catalytic performance, Ni nanoparticle-loaded microspheres can be developed. In this study, we have prepared Ni nanoparticle-loaded microspheres (SiO2@Ni) and hollow Ni microspheres using two-step method. SiO2@Ni microspheres with raspberry-like morphology and core-shell structure are synthesized successfully using SiO2 microsphere as a template and Ni2+ ions are adsorbed onto SiO2 surfaces via electrostatic interaction and then reduced and deposited on surfaces of SiO2 microspheres. Next, the SiO2 cores are removed by NaOH etching and the hollow Ni microspheres are prepared. The NaOH etching time does no have much influence on the crystal structure, shape, and surface morphology of SiO2@Ni; however, it can change the phase composition evidently. The hollow Ni microspheres are obtained when the NaOH etching time reaches 10 h and above. The as-synthesized SiO2@Ni microspheres exhibit much higher catalytic performance than the hollow Ni microspheres and pure Ni nanoparticles in the catalytic reduction of methylene blue. Meanwhile, the SiO2@Ni catalyst has high stability and hence it can be recycled for reuse.

Directional Solidification and Mechanical Properties of NiAl-NiAlTa Alloys

NASA Technical Reports Server (NTRS)

Johnson, D. R.; Chen, X. F.; Oliver, B. F.; Noebe, R. D.; Whittenberger, J. D.

1995-01-01

Directional solidification of eutectic alloys is a promising technique for producing in-situ composite materials exhibiting a balance of properties. Consequently, the microstructure, creep strength and fracture toughness of directionally solidified NiAl-NiAlTa alloys were investigated. Directional solidification was performed by containerless processing techniques to minimize alloy contamination. The eutectic composition was found to be NiAl-15.5 at% Ta and well-aligned microstructures were produced at this composition. A near-eutectic alloy of NiAl-14.5Ta was also investigated. Directional solidification of the near-eutectic composition resulted in microstructures consisting of NiAl dendrites surrounded by aligned eutectic regions. The off-eutectic alloy exhibited promising compressive creep strengths compared to other NiAl-based intermetallics, while preliminary testing indicated that the eutectic alloy was competitive with Ni-base single crystal superalloys. The room temperature toughness of these two-phase alloys was similar to that of polycrystalline NiAl even with the presence of the brittle Laves phase NiAlTa.

Hierarchical NiCo2 S4 Nanotube@NiCo2 S4 Nanosheet Arrays on Ni Foam for High-Performance Supercapacitors.

PubMed

Chen, Haichao; Chen, Si; Shao, Hongyan; Li, Chao; Fan, Meiqiang; Chen, Da; Tian, Guanglei; Shu, Kangying

2016-01-01

Hierarchical NiCo2 S4 nanotube@NiCo2 S4 nanosheet arrays on Ni foam have been successfully synthesized. Owing to the unique hierarchical structure, enhanced capacitive performance can be attained. A specific capacitance up to 4.38 F cm(-2) is attained at 5 mA cm(-2) , which is much higher than the specific capacitance values of NiCo2 O4 nanosheet arrays, NiCo2 S4 nanosheet arrays and NiCo2 S4 nanotube arrays on Ni foam. The hierarchical NiCo2 S4 nanostructure shows superior cycling stability; after 5000 cycles, the specific capacitance still maintains 3.5 F cm(-2) . In addition, through the morphology and crystal structure measurement after cycling stability test, it is found that the NiCo2 S4 electroactive materials are gradually corroded; however, the NiCo2 S4 phase can still be well-maintained. Our results show that hierarchical NiCo2 S4 nanostructures are suitable electroactive materials for high performance supercapacitors. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Viscosities of Fe Ni, Fe Co and Ni Co binary melts

NASA Astrophysics Data System (ADS)

Sato, Yuzuru; Sugisawa, Koji; Aoki, Daisuke; Yamamura, Tsutomu

2005-02-01

Viscosities of three binary molten alloys consisting of the iron group elements, Fe, Ni and Co, have been measured by using an oscillating cup viscometer over the entire composition range from liquidus temperatures up to 1600 °C with high precision and excellent reproducibility. The viscosities measured showed good Arrhenius linearity for all the compositions. The viscosities of Fe, Ni and Co as a function of temperature are as follows: \\eqalign{ & \\log \\eta={-}0.6074 + 2493/T\\qquad for\\quad Fe\\\\ & \\log \\eta={-}0.5695 + 2157/T\\qquad for\\quad Ni \\\\ & \\log \\eta={-}0.6620 + 2430/T\\qquad for\\quad Co.} The isothermal viscosities of Fe-Ni and Fe-Co binary melts increase monotonically with increasing Fe content. On the other hand, in Ni-Co binary melt, the isothermal viscosity decreases slightly and then increases with increasing Co. The activation energy of Fe-Co binary melt increased slightly on mixing, and those of Fe-Ni and Ni-Co melts decreased monotonically with increasing Ni content. The above behaviour is discussed based on the thermodynamic properties of the alloys.

Facile synthesis of Ni/NiO@GO nanocomposites and its enhanced dielectric constant

NASA Astrophysics Data System (ADS)

Sarkar, S.; Giri, N.; Mondal, A.; Ray, R.

2018-05-01

Ni/NiO embedded Graphene Oxide (GO): Ni/NiO@GO is synthesized by citric acid assisted Pechini-type method. Structural and morphological characterizations are performed by X-ray powdered diffraction (XRD), field emission scanning electron microscopy (FESEM) and tunneling electron microscopy (TEM). Defects in GO sheets are probed by RAMAN spectroscopy. The temperature variation of dielectric constant (ɛR) and dielectric loss (tan δ) are investigated in the temperature range 300 - 400 K. Decoration of GO with Ni/NiO nanoparticles enhances its ɛR by˜55 times. Moreover, its dielectric constant measured at 5 MHz is found to be˜430 times to that of Ni/NiO along with the reduction of dielectric loss by a factor˜0.5. The enhanced dielectric constant makes the composite Ni/NiO@GO a potential candidate for using in ecologically friendly energy storage devices.

A magnetostructural study of linear NiII MnIII NiII, NiII CrIII NiII and triangular Ni(II)3 species containing (pyridine-2-aldoximato)nickel(II) unit as a building block.

PubMed

Weyhermüller, Thomas; Wagner, Rita; Khanra, Sumit; Chaudhuri, Phalguni

2005-08-07

Three trinuclear complexes, NiII MnIII NiII, NiII CrIII NiII and Ni(II)3 based on (pyridine-2-aldoximato)nickel(II) units are described. Two of them, and , contain metal-centers in linear arrangement, as is revealed by X-ray diffraction. Complex is a homonuclear complex in which the three nickel(II) centers are disposed in a triangular fashion. The compounds were characterized by various physical methods including cyclic voltammetric and variable-temperature (2-290 K) susceptibility measurements. Complexes and display antiferromagnetic exchange coupling of the neighbouring metal centers, while weak ferromagnetic spin exchange between the adjacent Ni II and Cr III ions in is observed. The experimental magnetic data were simulated by using appropriate models.

Kinetics of NiO and NiCl2 Hydrogen Reduction as Precursors and Properties of Produced Ni/Al2O3 and Ni-Pd/Al2O3 Catalysts

PubMed Central

Sokić, Miroslav; Kamberović, Željko; Nikolić, Vesna; Marković, Branislav; Korać, Marija; Anđić, Zoran; Gavrilovski, Milorad

2015-01-01

The objects of this investigation were the comparative kinetic analysis of the NiO and NiCl2 reduction by hydrogen during an induction period and elimination of the calcination during the synthesis of Ni/Al2O3 catalysts. The effect of temperature and time on NiO and NiCl2 reduction degrees was studied. Avrami I equation was selected as the most favorable kinetic model and used to determine activation energy of the NiO and NiCl2 reduction for the investigated temperature range (623–923 K) and time intervals (1–5 minutes). The investigation enabled reaching conclusions about the reaction ability and rate of the reduction processes. Afterward, Ni/Al2O3 catalysts were obtained by using oxide and chloride precursor for Ni. The catalysts were supported on alumina-based foam and prepared via aerosol route. Properties of the samples before and after low-temperature hydrogen reduction (633 K) were compared. Obtained results indicated that the synthesis of Ni/Al2O3 catalysts can be more efficient if chloride precursor for Ni is directly reduced by hydrogen during the synthesis process, without the calcination step. In addition, Ni-Pd/Al2O3 catalysts with different metal content were prepared by using chloride precursors. Lower reduction temperature was utilized and the chlorides were almost completely reduced at 533 K. PMID:25789335

Preferential diffusion in concentrated solid solution alloys: NiFe, NiCo and NiCoCr

DOE PAGES

Zhao, Shijun; Osetsky, Yuri; Zhang, Yanwen

2017-02-13

In single-phase concentrated solid-solution alloys (CSAs), including high entropy alloys (HEAs), remarkable mechanical properties are exhibited, as well as extraordinary corrosion and radiation resistance compared to pure metals and dilute alloys. But, the mechanisms responsible for these properties are unknown in many cases. In this work, we employ ab initio molecular dynamics based on density functional theory to study the diffusion of interstitial atoms in Ni and Ni-based face-centered cubic CSAs including NiFe, NiCo and NiCoCr. We model the defect trajectories over >100 ps and estimate tracer diffusion coefficients, correlation factors and activation energies. Furthermore, we found that the diffusionmore » mass transport in CSAs is not only slower than that in pure components, i.e. sluggish diffusion, but also chemically non-homogeneous. The results obtained here can be used in understanding and predicting the atomic segregation and phase separation in CSAs under irradiation conditions.« less

Effects of Ni particle morphology on cell performance of Na/NiCl2 battery

NASA Astrophysics Data System (ADS)

Kim, Mangi; Ahn, Cheol-Woo; Hahn, Byung-Dong; Jung, Keeyoung; Park, Yoon-Cheol; Cho, Nam-ung; Lee, Heesoo; Choi, Joon-Hwan

2017-11-01

Electrochemical reaction of Ni particle, one of active cathode materials in the Na/NiCl2 battery, occurs on the particle surface. The NiCl2 layer formed on the Ni particle surface during charging can disconnect the electron conduction path through Ni particles because the NiCl2 layer has very low conductivity. The morphology and size of Ni particles, therefore, need to be controlled to obtain high charge capacity and excellent cyclic retention. Effects of the Ni particle size on the cell performance were investigated using spherical Ni particles with diameters of 0.5 μm, 6 μm, and 50 μm. The charge capacities of the cells with spherical Ni particles increased when the Ni particle size becomes smaller because of their higher surface area but their charge capacities were significantly decreased with increasing cyclic tests owing to the disconnection of electron conduction path. The inferior cyclic retention of charge capacity was improved using reticular Ni particles which maintained the reliable connection for the electron conduction in the Na/NiCl2 battery. The charge capacity of the cell with the reticular Ni particles was higher than the cell with the small-sized spherical Ni particles approximately by 26% at 30th cycle.

One dimensional motion of interstitial clusters and void growth in Ni and Ni alloys

NASA Astrophysics Data System (ADS)

Yoshiie, T.; Ishizaki, T.; Xu, Q.; Satoh, Y.; Kiritani, M.

2002-12-01

One dimensional (1-D) motion of interstitial clusters is important for the microstructural evolution in metals. In this paper, the effect of 2 at.% alloying with elements Si (volume size factor to Ni: -5.81%), Cu (7.18%), Ge (14.76%) and Sn (74.08%) in Ni on 1-D motion of interstitial clusters and void growth was studied. In neutron irradiated pure Ni, Ni-Cu and Ni-Ge, well developed dislocation networks and voids in the matrix, and no defects near grain boundaries were observed at 573 K to a dose of 0.4 dpa by transmission electron microscopy. No voids were formed and only interstitial type dislocation loops were observed near grain boundaries in Ni-Si and Ni-Sn. The reaction kinetics analysis which included the point defect flow into planar sink revealed the existence of 1-D motion of interstitial clusters in Ni, Ni-Cu and Ni-Ge, and lack of such motion in Ni-Si and Ni-Sn. In Ni-Sn and Ni-Si, the alloying elements will trap interstitial clusters and thereby reduce the cluster mobility, which lead to the reduction in void growth.

Strong Ground Motion Simulation and Source Modeling of the April 1, 2006 Tai-Tung Earthquake Using Empirical Green's Function Method

NASA Astrophysics Data System (ADS)

Huang, H.; Lin, C.

2010-12-01

The Tai-Tung earthquake (ML=6.2) occurred at the southeastern part of Taiwan on April 1, 2006. We examine the source model of this event using the observed seismograms by CWBSN at five stations surrounding the source area. An objective estimation method was used to obtain the parameters N and C which are needed for the empirical Green’s function method by Irikura (1986). This method is called “source spectral ratio fitting method” which gives estimate of seismic moment ratio between a large and a small event and their corner frequencies by fitting the observed source spectral ratio with the ratio of source spectra which obeys the model (Miyake et al., 1999). This method has an advantage of removing site effects in evaluating the parameters. The best source model of the Tai-Tung mainshock in 2006 was estimated by comparing the observed waveforms with synthetics using empirical Green’s function method. The size of the asperity is about 3.5 km length along the strike direction by 7.0 km width along the dip direction. The rupture started at the left-bottom of the asperity and extended radially to the right-upper direction.

Thermodynamic characterization of Ni3TeO6, Ni2Te3O8 and NiTe2O5

NASA Astrophysics Data System (ADS)

Dawar, Rimpi; Babu, R.; Ananthasivan, K.; Anthonysamy, S.

2017-09-01

Measurement of vapour pressure of TeO2(g) over the biphasic mixture Ni3TeO6 (s) + NiO(s) in the temperature range 1143-1272 K was carried out using transpiration-thermogravimetric technique (TTG). Gibbs energy of formation of Ni3TeO6 was obtained from the temperature dependence of vapour pressure of TeO2 (g) generated by the incongruent vapourisation reaction, Ni3TeO6 (s) → NiO(s) + TeO2 (g) + 1/2 O2 in the temperature range 1143-1272 K. An isoperibol type drop calorimeter was used to measure the enthalpy increments of Ni3TeO6, Ni2Te3O8 and NiTe2O5. Thermodynamic functions viz., heat capacity, entropy and Gibbs energy functions of these compounds were derived from the experimentally measured enthalpy increment values. Third-law analysis was carried out to ascertain absence of temperature dependent systematic errors in the measurement of vapour pressure of TeO2 (g). A value of -1265.1 ± 1.5 kJ mol-1 was obtained for Δ Hf,298K o (Ni3TeO6) using third-law analysis.

Superaerophobic P-doped Ni(OH)2/NiMoO4 hierarchical nanosheet arrays grown on Ni foam for electrocatalytic overall water splitting.

PubMed

Xi, Wenguang; Yan, Gang; Tan, Huaqiao; Xiao, Liguang; Cheng, Sihang; Khan, Shifa Ullah; Wang, Yonghui; Li, Yangguang

2018-06-19

Transition metal (TM) oxides and hydroxides are one of the important candidates for the development of durable and low-cost electrocatalysts towards water splitting. The key issue is exploring effective methods to improve their electrocatalytic activity. Herein, we report a new type of P-doped Ni(OH)2/NiMoO4 hierarchical nanosheet array (abbr. P-Ni(OH)2/NiMoO4) grown on Ni foam (NF), which can act as a highly efficient electrocatalyst towards overall water splitting. Such a composite was obtained by a three-step preparation process. In the first two hydrothermal reactions, the crystalline Ni(OH)2 hierarchical nanosheet arrays were grown on NF and then the low crystallinity NiMoO4 was grafted on the Ni(OH)2 nanosheets. In the third phosphorization step, P element was doped into the composite Ni(OH)2/NiMoO4. Electrocatalytic experiments show that P-Ni(OH)2/NiMoO4 possesses a smaller overpotential (60 mV) and lower Tafel slope (130 mV dec-1) toward HER in 1 M KOH. When it was employed as an integrated water splitting catalyst, only a potential of 1.55 V was required to achieve a current density of 10 mA cm-2. This catalytic activity is even better than those of electrolyzers constructed with noble metals Pt/C∥IrO2. The superior electrocatalytic performance of P-Ni(OH)2/NiMoO4 can be attributed to the high quality of crystalline Ni(OH)2 nanosheet arrays grown on NF, which dramatically improve the conductivity. Furthermore, the hierarchical structure not only increases the surface area and exposes more catalytically active sites, but also provides a superaerophobic surface, which helps to accelerate the release of generated bubbles. Moreover, the synergistic effects between P-Ni(OH)2 and P-NiMoO4 efficiently promote the HER and OER processes also. This work may suggest new a way to explore TM oxide/hydroxide-based durable electrocatalysts with highly efficient electrocatalytic activities towards overall water splitting.

Ni-Co laterite deposits

USGS Publications Warehouse

Marsh, Erin E.; Anderson, Eric D.

2011-01-01

Nickel-cobalt (Ni-Co) laterite deposits are an important source of nickel (Ni). Currently, there is a decline in magmatic Ni-bearing sulfide lode deposit resources. New efforts to develop an alternative source of Ni, particularly with improved metallurgy processes, make the Ni-Co laterites an important exploration target in anticipation of the future demand for Ni. This deposit model provides a general description of the geology and mineralogy of Ni-Co laterite deposits, and contains discussion of the influences of climate, geomorphology (relief), drainage, tectonism, structure, and protolith on the development of favorable weathering profiles. This model of Ni-Co laterite deposits represents part of the U.S. Geological Survey Mineral Resources Program's effort to update the existing models to be used for an upcoming national mineral resource assessment.

Water dissociation on Ni(100), Ni(110), and Ni(111) surfaces: Reaction path approach to mode selectivity

DOE PAGES

Seenivasan, H.; Jackson, Bret; Tiwari, Ashwani K.

2017-02-17

We performed a comparative study of mode-selectivity of water dissociation on Ni(100), Ni(110), and Ni(111) surfaces at the same level of theory using a fully quantum approach based on the reaction path Hamiltonian. Calculations show that the barrier to water dissociation on the Ni(110) surface is significantly lower compared to its close-packed counterparts. Transition states for this reaction on all three surfaces involve the elongation of one of the O–H bonds. Furthermore, a significant decrease in the symmetric stretching and bending mode frequencies near the transition state is observed in all three cases and in the vibrational adiabatic approximation, excitationmore » of these softened modes results in a significant enhancement in reactivity. Inclusion of non-adiabatic couplings between modes results in the asymmetric stretching mode showing a similar enhancement of reactivity as the symmetric stretching mode. Dissociation probabilities calculated at a surface temperature of 300 K showed higher reactivity at lower collision energies compared to that of the static surface case, underlining the importance of lattice motion in enhancing reactivity. Mode selective behavior is similar on all the surfaces. Molecules with one-quantum of vibrational excitation in the symmetric stretch, at lower energies (up to 0.45 eV), are more reactive on Ni(110) than the Ni(100) and Ni(111) surfaces. But, the dissociation probabilities approach saturation on all the surfaces at higher incident energy values. Ultimately, Ni(110) is found to be highly reactive toward water dissociation among the low-index nickel surfaces owing to a low reaction barrier resulting from the openness and corrugation of the surface. These results show that the mode-selective behavior does not vary with different crystal facets of Ni qualitatively, but there is a significant quantitative effect.« less

Water dissociation on Ni(100), Ni(110), and Ni(111) surfaces: Reaction path approach to mode selectivity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seenivasan, H.; Jackson, Bret; Tiwari, Ashwani K.

We performed a comparative study of mode-selectivity of water dissociation on Ni(100), Ni(110), and Ni(111) surfaces at the same level of theory using a fully quantum approach based on the reaction path Hamiltonian. Calculations show that the barrier to water dissociation on the Ni(110) surface is significantly lower compared to its close-packed counterparts. Transition states for this reaction on all three surfaces involve the elongation of one of the O–H bonds. Furthermore, a significant decrease in the symmetric stretching and bending mode frequencies near the transition state is observed in all three cases and in the vibrational adiabatic approximation, excitationmore » of these softened modes results in a significant enhancement in reactivity. Inclusion of non-adiabatic couplings between modes results in the asymmetric stretching mode showing a similar enhancement of reactivity as the symmetric stretching mode. Dissociation probabilities calculated at a surface temperature of 300 K showed higher reactivity at lower collision energies compared to that of the static surface case, underlining the importance of lattice motion in enhancing reactivity. Mode selective behavior is similar on all the surfaces. Molecules with one-quantum of vibrational excitation in the symmetric stretch, at lower energies (up to 0.45 eV), are more reactive on Ni(110) than the Ni(100) and Ni(111) surfaces. But, the dissociation probabilities approach saturation on all the surfaces at higher incident energy values. Ultimately, Ni(110) is found to be highly reactive toward water dissociation among the low-index nickel surfaces owing to a low reaction barrier resulting from the openness and corrugation of the surface. These results show that the mode-selective behavior does not vary with different crystal facets of Ni qualitatively, but there is a significant quantitative effect.« less

Structural and magnetic properties of Ni-Zn and Ni-Zn-Co ferrites

NASA Astrophysics Data System (ADS)

Knyazev, A. V.; Zakharchuk, I.; Lähderanta, E.; Baidakov, K. V.; Knyazeva, S. S.; Ladenkov, I. V.

2017-08-01

Ni-Zn and Ni-Zn-Co ferrite powders with nominal compositions Ni0.5Zn0.5Fe2O4 and Ni0.5Zn0.3Co0.2Fe2O4 were prepared by the solid-state reaction synthesis with periodic regrinding during the calcination at 1073 K. The structure of Ni0.5Zn0.5Fe2O4 and Ni0.5Zn0.3Co0.2Fe2O4 was refined assuming space group F d-3m. Scanning electron microscopy revealed the average sizes of the crystalline ferrite particles are 130-630 nm for Ni0.5Zn0.5Fe2O4 and 140-350 nm for Ni0.5Zn0.3Co0.2Fe2O4. The room temperature saturation magnetizations are 59.7 emu/g for Ni0.5Zn0.5Fe2O4 and 57.1 emu/g for Ni0.5Zn0.3Co0.2Fe2O4. The coercivity of the samples is found to be much larger than that of bulk ferrites and increases with Co introduction. The Curie temperature tends to increase upon Zn substitution by Co, as well. The temperature dependences of magnetization measured using zero-field cooled and field cooled protocols exhibit large spin frustration and spin-glass-like behavior.

Comparative effectiveness of NiCl2, Ni- and NiO-NPs in controlling oral bacterial growth and biofilm formation on oral surfaces.

PubMed

Khan, Shams Tabrez; Ahamed, Maqusood; Alhadlaq, Hisham A; Musarrat, Javed; Al-Khedhairy, Abdulaziz

2013-12-01

Oral ailments are often treated with antibiotics, which are rendered ineffective as bacteria continue to develop resistance against them. It has been suggested that the nanoparticles (NPs) approach may provide a safer and viable alternative to traditional antibacterial agents. Therefore, nickel (Ni)- and nickel oxide (NiO)-NPs were synthesized, characterized and assessed for their efficacy in reducing oral bacterial load in vitro. Also, the effects of bulk compound NiCl2 (Ni ions), along with the Ni- and NiO-NPs on bacterial exopolysaccharide (EPS) production and biofilm formation on the surface of artificial teeth, and acrylic dentures, were investigated. Total bacteria from a healthy male were collected and adjusted to 4×109cells/ml for all the tests. Effect of the NPs on growth, biofilm formation, EPS production and acid production from glucose was tested using standard protocols. Data revealed that the Ni-NPs (average size 41.23nm) exhibited an IC50 value of 73.37μg/ml against total oral bacteria. While, NiO-NPs (average size 35.67nm) were found less effective with much higher IC50 value of 197.18μg/ml. Indeed, the Ni ions exhibited greater biocidal activity with an IC50 value of 70μg/ml. Similar results were obtained with biofilm inhibition on the surfaces of dental prostheses. The results explicitly suggested the effectiveness of tested Ni compounds on the growth of oral bacteria and biofilm formation in the order as NiCl2>Ni-NPs>NiO-NPs. The results elucidated that Ni-NPs could serve as effective nanoantibiotics against oral bacteria. Copyright © 2013 Elsevier Ltd. All rights reserved.

Growth of Ni-Al alloys on Ni(1 1 1), from Al deposits of various thicknesses: (II) Formation of NiAl over a Ni 3Al interfacial layer

NASA Astrophysics Data System (ADS)

Le Pévédic, S.; Schmaus, D.; Cohen, C.

2007-01-01

This paper describes the second part of a study devoted to the growth of thin Ni-Al alloys after deposition of Al on Ni(1 1 1). In the previous paper [S. Le Pévédic, D. Schmaus, C. Cohen, Surf. Sci. 600 (2006) 565] we have described the results obtained for ultra-thin Al deposits, leading, after annealing at 750 K, to an epitaxial layer of Ni 3Al(1 1 1). In the present paper we show that this regime is only observed for Al deposits smaller than 8 × 10 15 Al/cm 2 and we describe the results obtained for Al deposits exceeding this critical thickness, up to 200 × 10 15 Al/cm 2. Al deposition was performed at low temperature (around 130 K) and the alloying process was followed in situ during subsequent annealing, by Auger electron spectroscopy, low energy electron diffraction and ion beam analysis-channeling measurements, in an ultra-high vacuum chamber connected to a Van de Graaff accelerator. We evidence the formation, after annealing at 750 K, of a crystallographically and chemically well-ordered NiAl(1 1 0) layer (whose thickness depends on the deposited Al amount), over a Ni 3Al "interfacial" layer (whose thickness—about 18 (1 1 1) planes—is independent of the deposited Al amount). The NiAl overlayer is composed of three variants, at 120° from each other in the surface plane, in relation with the respective symmetries of NiAl(1 1 0) and Ni 3Al(1 1 1). The NiAl layer is relaxed (the lattice parameters of cc-B2 NiAl and fcc-L1 2 Ni 3Al differ markedly), and we have determined its epitaxial relationship. In the case of the thickest alloyed layer formed the results concerning the structure of the NiAl layer have been confirmed and refined by ex situ X-ray diffraction and information on its grain size has been obtained by ex situ Atomic Force Microscopy. The kinetics of the alloying process is complex. It corresponds to an heterogeneous growth leading, above the thin Ni 3Al interfacial layer, to a mixture of Al and NiAl over the whole Al film, up to the

Fine Structure in Multi-Phase Zr8Ni21-Zr7Ni10-Zr2Ni7 Alloy Revealed by Transmission Electron Microscope

PubMed Central

Shen, Haoting; Bendersky, Leonid A.; Young, Kwo; Nei, Jean

2015-01-01

The microstructure of an annealed alloy with a Zr8Ni21 composition was studied by both scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The presence of three phases, Zr8Ni21, Zr2Ni7, and Zr7Ni10, was confirmed by SEM/X-ray energy dispersive spectroscopy compositional mapping and TEM electron diffraction. Distribution of the phases and their morphology can be linked to a multi-phase structure formed by a sequence of reactions: (1) L → Zr2Ni7 + L’; (2) peritectic Zr2Ni7 + L’ → Zr2Ni7 + Zr8Ni21 + L”; (3) eutectic L” → Zr8Ni21 + Zr7Ni10. The effect of annealing at 960 °C, which was intended to convert a cast structure into a single-phase Zr8Ni21 structure, was only moderate and the resulting alloy was still multi-phased. TEM and crystallographic analysis of the Zr2Ni7 phase show a high density of planar (001) defects that were explained as low-energy boundaries between rotational variants and stacking faults. The crystallographic features arise from the pseudo-hexagonal structure of Zr2Ni7. This highly defective Zr2Ni7 phase was identified as the source of the broad X-ray diffraction peaks at around 38.4° and 44.6° when a Cu-K was used as the radiation source. PMID:28793460

Heteromorphic NiCo2S4/Ni3S2/Ni Foam as a Self-Standing Electrode for Hydrogen Evolution Reaction in Alkaline Solution.

PubMed

Liu, Hui; Ma, Xiao; Rao, Yuan; Liu, Yang; Liu, Jialiang; Wang, Luyang; Wu, Mingbo

2018-04-04

Considerable works have been devoted on developing high-efficiency nonplatinum electrocatalysts for hydrogen evolution reaction (HER). Herein, 3D heteromorphic NiCo 2 S 4 /Ni 3 S 2 nanosheets network has been constructed on Ni foam (denoted as NiCo 2 S 4 /Ni 3 S 2 /NF) serving as a self-standing electrocatalyst through directly thermal sulfurization of a single-source NiCo-layered double hydroxide precursor. The resultant NiCo 2 S 4 /Ni 3 S 2 /NF electrode exhibits outstanding electrocatalytic HER performance with an extremely low onset overpotential of 15 mV and long-term durability in alkaline solution. Such enhanced HER performance can be credited to (1) the massive exposed active sites provided by mixed transition metal chalcogenides (NiCo 2 S 4 and Ni 3 S 2 ), (2) the strong interfacial interaction at NiCo 2 S 4 /Ni 3 S 2 heterojunction interfaces with the strengthened H binding, and (3) the porous highly conductive Ni foam substrate with accelerated electron transfer. This work opens up a new direction to fabricate effective and non-noble-metal electrodes for water splitting and hydrogen generation.

Low-field spin dynamics of Cr7Ni and Cr7Ni-Cu -Cr 7Ni molecular rings as detected by μ SR

NASA Astrophysics Data System (ADS)

Sanna, S.; Arosio, P.; Bordonali, L.; Adelnia, F.; Mariani, M.; Garlatti, E.; Baines, C.; Amato, A.; Sabareesh, K. P. V.; Timco, G.; Winpenny, R. E. P.; Blundell, S. J.; Lascialfari, A.

2017-11-01

Muon spin rotation measurements were used to investigate the spin dynamics of heterometallic Cr7Ni and Cr7Ni -Cu-Cr7Ni molecular clusters. In Cr7Ni the magnetic ions are arranged in a quasiplanar ring and interact via an antiferromagnetic exchange coupling constant J , while Cr7Ni -Cu-Cr7Ni is composed of two Cr7Ni linked by a bridging moiety containing one Cu ion, that induces an inter-ring ferromagnetic interaction J'≪J . The longitudinal muon relaxation rate λ collected at low magnetic fields μ0H <0.15 Tesla, shows that the two systems present differences in spin dynamics vs temperature. While both samples exhibit a main peak in the muon relaxation rate vs temperature, at T ˜10 K for Cr7Ni and T ˜8 K for Cr7Ni -Cu-Cr7Ni , the two compounds have distinct additional features: Cr7Ni shows a shoulder in λ (T ) for T <8 K, while Cr7Ni -Cu-Cr7Ni shows a flattening of λ (T ) for T <2 K down to temperatures as low as T =20 mK. The main peak of both systems is explained by a Bloembergen-Purcell-Pound (BPP)-like heuristic fitting model that takes into account of a distribution of electronic spin characteristic times for T >5 K, while the shoulder presented by Cr7Ni can be reproduced by a BPP function that incorporates a single electronic characteristic time theoretically predicted to dominate for T <5 K. The flattening of λ (T ) in Cr7Ni -Cu-Cr7Ni occurring at very low temperature can be tentatively attributed to field-dependent quantum effects and/or to an inelastic term in the spectral density of the electronic spin fluctuations.

The management of behavioural and psychological symptoms of dementia in residential homes: does Tai Chi have any role for people with dementia?

PubMed

Tadros, George; Ormerod, Sara; Dobson-Smyth, Penny; Gallon, Mark; Doherty, Donna; Carryer, Angela; Oyebode, Jan; Kingston, Paul

2013-03-01

Dementia is a common illness that is increasing in frequency and set to challenge the resources and expertise of health and social care services over the coming years. Increasingly, there has been interest in the management of behavioural and psychological symptoms of dementia (BPSD), as they are both common and associated with a range of negative outcomes. BPSD are associated with the admission of people with dementia to care homes. Limited resources and lack of knowledge in permanent care settings often lead to BPSD being managed with antipsychotic medications, which are associated with significant morbidity and mortality. There is evidence for the benefits of exercise within care home settings, although only a few studies include those with cognitive impairment. Tai Chi is a mind-body exercise combining relaxed physical movement and meditation, and has been suggested to have many health benefits. This article discusses the rationale and available options for treating BPSD and the current practice and reviews the literature regarding the benefits of exercise and, in particular, Tai Chi in the management of BPSD.

Preparation and properties of TiC-Ni cermets using Ni-plated TiC

NASA Astrophysics Data System (ADS)

Shin, Soon-Gi

2002-04-01

TiC powders were coated with Ni by a chemical plating technique and the pressed compacts sintered at 1623K. The density of the sintered bodies was 98-99%. Compared with mechanically-mixed powder, Ni-plated TiC powders gave a more uniform microstructure in which TiC particles were well dispersed in the Ni matrix. The cermets exhibited ductile fracture for TiC-70 vol.% Ni and brittle fracture for TiC-30 vol.% Ni. The flexural strength was improved by the homogeneous dispersion of TiC. The thermal expansion coefficient increased with a decrease in Ni content, following a nearly linear law of mixtures on the basis of volume fractions of pure TiC and Ni.

Tai Chi training for patients with coronary heart disease.

PubMed

Lan, Ching; Chen, Ssu-Yuan; Wong, May-Kuen; Lai, Jin-Shin

2008-01-01

Coronary heart disease (CHD) is the leading cause of death in the developed countries and many developing countries. Exercise training is the cornerstone of cardiac rehabilitation program for patients with CHD, and exercise intensities in the 50-70% heart rate reserve have been shown to improve functional capacity. However, recent studies found exercise with lower intensity also displayed benefits to CHD patients, and increased the acceptance of exercise program, particularly unfit and elderly patients. Tai Chi Chuan (TC) is a traditional conditioning exercise in the Chinese community, and recently it has become more popular in the Western societies. The exercise intensity of TC is low to moderate, depending on the training style, posture and duration. Participants can choose to perform a complete set of TC or selected movements according to their needs. Previous research substantiates that TC enhances aerobic capacity, muscular strength, endothelial function and psychological wellbeing. In addition, TC reduces some cardiovascular risk factors, such as hypertension and dyslipidemia. Recent studies have also proved that TC is safe and effective for patients with myocardial infarction, coronary bypass surgery and heart failure. Therefore, TC may be prescribed as an alternative exercise program for selected patients with cardiovascular diseases. In conclusion, TC has potential benefits for patients with CHD, and is appropriate for implementation in the community.

Synthesis of a novel Au nanoparticles decorated Ni-MOF/Ni/NiO nanocomposite and electrocatalytic performance for the detection of glucose in human serum.

PubMed

Chen, Jingyuan; Xu, Qin; Shu, Yun; Hu, Xiaoya

2018-07-01

A nonenzymatic glucose electrochemical sensor was constructed based on Au nanoparticles (AuNPs) decorated Ni metal-organic-framework (MOF)/Ni/NiO nanocomposite. Ni-MOF/Ni/NiO nanocomposite was synthesized by one-step calcination of Ni-MOF. Then AuNPs were loaded onto the Ni-based nanocomposites' surface through electrostatic adsorption. Through characterization by transmission electron microscopy (TEM), high resolution TEM (HRTEM) and energy disperse spectroscopy (EDS) mapping, it is found that the AuNPs were well distributed on the surface of Ni-based nanocomposite. Cyclic voltammetric (CV) study showed the electrocatalytic activity of Au-Ni nanocomposite was highly improved after loading AuNPs onto it. Amperometric study demonstrated that the Au-Ni nanocomposites modified glassy carbon electrode (GCE) exhibited a high sensitivity of 2133.5 mA M -1 cm -2 and a wide linear range (0.4-900 μM) toward the oxidation of glucose with a detection limit as low as 0.1 μM. Moreover, the reproducibility, selectivity and stability of the sensor all exhibited outstanding performance. We applied the as-fabricated high performance sensor to measure the glucose levels in human serum and obtained satisfactory results. It is believed that AuNPs decorated Ni MOF/Ni/NiO nanocomposite provides a new platform for developing highly performance electrochemical sensors in practical applications. Copyright © 2018 Elsevier B.V. All rights reserved.

Anisotropic growth of NiO nanorods from Ni nanoparticles by rapid thermal oxidation.

PubMed

Koga, Kenji; Hirasawa, Makoto

2013-09-20

NiO nanorods with extremely high crystallinity were grown by rapid thermal oxidation through exposure of Ni nanoparticles (NPs) heated above 400° C to oxygen. Oxidation proceeds by nucleation of a NiO island on a Ni NP that grows anisotropically to produce a NiO nanorod. This process differs completely from that under mild oxidation conditions, where the surface of the NPs is completely covered with an oxide film during the early stage of oxidation. The observed novel behaviour strongly suggests an interfacial oxidation mechanism driven by the dissolution of adsorbed oxygen into the Ni NP sub-surface region, subsequent diffusion and reaction at the NiO/Ni interface. The early oxidation conditions of metal NPs impose a significant influence on the entire oxidation process at the nanoscale and are therefore inherently important for the precise morphological control of oxidized NPs to design functional nanomaterials.

Temperature-dependent selective oxidation processes for Ni-5Cr and Ni-4Al

DOE PAGES

Kruska, Karen; Schreiber, Daniel K.; Olszta, Matthew J.; ...

2018-05-09

The selective oxidation of Ni-5Cr and Ni-4 Al alloys is evaluated during high (800 °C) and low (420 °C) temperature exposures with the oxygen partial pressure moderated by a Ni/NiO powder buffer. Internal oxidation of Cr and Al is observed throughout the matrix and at grain boundaries at 800 °C accompanied by the ejection of Ni onto the surface for both. At 420 °C, matrix internal oxidation was eliminated and only Ni-4 Al exhibited intergranular (IG) oxidation. Surprisingly, a protective surface oxide rapidly formed for Ni-5Cr blocking IG oxidation. Finally, this is contradictory to results in 330–360 °C hydrogenated watermore » environments where both alloys show IG oxidation.« less

Temperature-dependent selective oxidation processes for Ni-5Cr and Ni-4Al

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kruska, Karen; Schreiber, Daniel K.; Olszta, Matthew J.

The selective oxidation of Ni-5Cr and Ni-4 Al alloys is evaluated during high (800 °C) and low (420 °C) temperature exposures with the oxygen partial pressure moderated by a Ni/NiO powder buffer. Internal oxidation of Cr and Al is observed throughout the matrix and at grain boundaries at 800 °C accompanied by the ejection of Ni onto the surface for both. At 420 °C, matrix internal oxidation was eliminated and only Ni-4 Al exhibited intergranular (IG) oxidation. Surprisingly, a protective surface oxide rapidly formed for Ni-5Cr blocking IG oxidation. Finally, this is contradictory to results in 330–360 °C hydrogenated watermore » environments where both alloys show IG oxidation.« less

Nickel Release, ROS Generation and Toxicity of Ni and NiO Micro- and Nanoparticles

PubMed Central

Hedberg, Jonas; Di Bucchianico, Sebastiano; Möller, Lennart; Odnevall Wallinder, Inger; Elihn, Karine; Karlsson, Hanna L.

2016-01-01

Occupational exposure to airborne nickel is associated with an elevated risk for respiratory tract diseases including lung cancer. Therefore, the increased production of Ni-containing nanoparticles necessitates a thorough assessment of their physical, chemical, as well as toxicological properties. The aim of this study was to investigate and compare the characteristics of nickel metal (Ni) and nickel oxide (NiO) particles with a focus on Ni release, reactive oxygen species (ROS) generation, cellular uptake, cytotoxicity and genotoxicity. Four Ni-containing particles of both nano-size (Ni-n and NiO-n) and micron-size (Ni-m1 and Ni-m2) were tested. The released amount of Ni in solution was notably higher in artificial lysosomal fluid (e.g. 80–100 wt% for metallic Ni) than in cell medium after 24h (ca. 1–3 wt% for all particles). Each of the particles was taken up by the cells within 4 h and they remained in the cells to a high extent after 24 h post-incubation. Thus, the high dissolution in ALF appeared not to reflect the particle dissolution in the cells. Ni-m1 showed the most pronounced effect on cell viability after 48 h (alamar blue assay) whereas all particles showed increased cytotoxicity in the highest doses (20–40 μg cm2) when assessed by colony forming efficiency (CFE). Interestingly an increased CFE, suggesting higher proliferation, was observed for all particles in low doses (0.1 or 1 μg cm-2). Ni-m1 and NiO-n were the most potent in causing acellular ROS and DNA damage. However, no intracellular ROS was detected for any of the particles. Taken together, micron-sized Ni (Ni-m1) was more reactive and toxic compared to the nano-sized Ni. Furthermore, this study underlines that the low dose effect in terms of increased proliferation observed for all particles should be further investigated in future studies. PMID:27434640

Single-Layer graphene growth on crystalline Ni(111) and Ni(110) and the fate of Carbon on crystalline Ni(100).

NASA Astrophysics Data System (ADS)

Araujo, Paulo; Mafra, Daniela; Reina, Alfonso; Shin, Young Cheol; Kim, Ki Kang; Dresselhaus, Mildred; Kong, Jing

The growth of large area single-layer graphene (1-LG) is studied using ambient pressure CVD on single crystal Ni(111), Ni(110) and Ni(100). By varying both the furnace temperature in the range of 700 - 1100oC and the gas flow through the growth chamber, a uniform growth of high-quality 1-LG is obtained for Ni(111) and Ni(110), but only multilayer graphene (M-LG) growth could be obtained for Ni(100). The experimental results are interpreted to obtain the optimum combination of temperature and gas flow, and the results reported in this manuscript are interpreted through different thermodynamic mechanisms, such as diffusion, segregation and adsorption, which dictate the formation of different carbon structures over the different crystallographic directions of Ni. Characterization with optical microscopy, Raman spectroscopy and optical transmission accordingly support the experimental findings. DOE Award Number DE-SC0001088, College of Arts and Sciences at the University of Alabama, NRF Award Number 2015R1C1A1A02037083 and NSF-DMR 1507806.

The reactivity of Fe/Ni colloid stabilized by carboxymethylcellulose (CMC-Fe/Ni) toward chloroform.

PubMed

Jin, Xin; Li, Qun; Yang, Qi

2018-05-16

The use of stabilizers can prevent the reactivity loss of nanoparticles due to aggregation. In this study, carboxymethylcellulose (CMC) was selected as the stabilizer to synthesize a highly stable CMC-stabilized Fe/Ni colloid (CMC-Fe/Ni) via pre-aggregation stabilization. The reactivity of CMC-Fe/Ni was evaluated via the reaction of chloroform (CF) degradation. The effect of background solution which composition was affected by the preparation of Fe/Ni (Fe/Ni precursors, NaBH 4 dosage) and the addition of solute (common ions, sulfur compounds) on the reactivity of CMC-Fe/Ni was also investigated. Additionally, the dried CMC-Fe/Ni was used for characterization in terms of scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The experimental results indicated that CMC stabilization greatly improved the reactivity of Fe/Ni bimetal and CF (10 mg/L) could be completely degraded by CMC-Fe/Ni (0.1 g/L) within 45 min. The use of different Fe/Ni precursors resulting in the variations of background solution seemed to have no obvious influence on the reactivity of CMC-Fe/Ni, whereas the dosage of NaBH 4 in background solution showed a negative correlation with the reactivity of CMC-Fe/Ni. Besides, the individual addition of external solutes into background solution all had an adverse effect on the reactivity of CMC-Fe/Ni, of which the poisoning effect of sulfides (Na 2 S, Na 2 S 2 O 4 ) was significant than common ions and sulfite.

Composite Ni/NiO-Cr2O3 Catalyst for Alkaline Hydrogen Evolution Reaction

PubMed Central

Bates, Michael K.; Jia, Qingying; Ramaswamy, Nagappan; Allen, Robert J.; Mukerjee, Sanjeev

2015-01-01

We report a Ni–Cr/C electrocatalyst with unprecedented mass-activity for the hydrogen evolution reaction (HER) in alkaline electrolyte. The HER kinetics of numerous binary and ternary Ni-alloys and composite Ni/metal-oxide/C samples were evaluated in aqueous 0.1 M KOH electrolyte. The highest HER mass-activity was observed for Ni–Cr materials which exhibit metallic Ni as well as NiOx and Cr2O3 phases as determined by X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) analysis. The onset of the HER is significantly improved compared to numerous binary and ternary Ni-alloys, including Ni–Mo materials. It is likely that at adjacent Ni/NiOx sites, the oxide acts as a sink for OHads, while the metallic Ni acts as a sink for the Hads intermediate of the HER, thus minimizing the high activation energy of hydrogen evolution via water reduction. This is confirmed by in situ XAS studies that show that the synergistic HER enhancement is due to NiOx content and that the Cr2O3 appears to stabilize the composite NiOx component under HER conditions (where NiOx would typically be reduced to metallic Ni0). Furthermore, in contrast to Pt, the Ni(Ox)/Cr2O3 catalyst appears resistant to poisoning by the anion exchange ionomer (AEI), a serious consideration when applied to an anionic polymer electrolyte interface. Furthermore, we report a detailed model of the double layer interface which helps explain the observed ensemble effect in the presence of AEI. PMID:26191118

Latest status of El Niño and La Niña

Science.gov Websites

Simplified Chinese El Niño and La Niña Latest status (May 2018) In the past month or so, the warming trend returned to normal in April 2018, indicating that the La Niña event had come to an end. Based on the ±o, La Niña, ENSO? The impact of El Niño and La Niña on the climate of Hong Kong Seasonal and

Properties of mechanically alloyed Mg-Ni-Ti ternary hydrogen storage alloys for Ni-MH batteries

NASA Astrophysics Data System (ADS)

Ruggeri, Stéphane; Roué, Lionel; Huot, Jacques; Schulz, Robert; Aymard, Luc; Tarascon, Jean-Marie

MgNiTi x, Mg 1- xTi xNi and MgNi 1- xTi x (with x varying from 0 to 0.5) alloys have been prepared by high energy ball milling and tested as hydrogen storage electrodes. The initial discharge capacities of the Mg-Ni-Ti ternary alloys are inferior to the MgNi electrode capacity. However, an exception is observed with MgNi 0.95Ti 0.05, which has an initial discharge capacity of 575 mAh/g compared to 522 mAh/g for the MgNi electrode. The Mg-Ni-Ti ternary alloys show improved cycle life compared to Mg-Ni binary alloys with the same Mg/Ni atomic ratio. The best cycle life is observed with Mg 0.5Ti 0.5Ni electrode which retains 75% of initial capacity after 10 cycles in comparison to 39% for MgNi electrodes, in addition to improved high-rate dischargeability (HRD). According to the XPS analysis, the cycle life improvement of the Mg 0.5Ti 0.5Ni electrode can be related to the formation of TiO 2 which limits Mg(OH) 2 formation. The anodic polarization curve of Mg 0.5Ti 0.5Ni electrode shows that the current related to the active/passive transition is much less important and that the passive region is more extended than for the MgNi electrode but the corrosion of the electrode is still significant. This suggests that the cycle life improvement would be also associated with a decrease of the particle pulverization upon cycling.

Ni-P/Zn-Ni compositionally modulated multilayer coatings - Part 2: Corrosion and protection mechanisms

NASA Astrophysics Data System (ADS)

Bahadormanesh, Behrouz; Ghorbani, Mohammad

2018-06-01

The Ni-P/Zn-Ni compositionally modulated multilayer coatings CMMCs were electrodeposited from a single bath by switching the deposition current density. The corrosion resistance of the deposits was studied and compared with that of monolayers of Ni-P and Zn-Ni alloys via Tafel polarization, EIS and salt spray tests. Characterization of corrosion products by means of EDS and XRD revealed more details from the corrosion mechanism of the monolayers and multilayers. The corrosion current density of Ni-P/Zn-Ni CMMCs were around one tenth of Zn-Ni monolayer. The CMMC with incomplete layers performed lower polarization resistance and higher corrosion current density compared to the CMMC with complete layers. The electrical circuit that was proposed for modeling the corrosion process based on the EIS spectrum, proved that layering reduces the porosity and consequently improves the barrier properties. Although, layering of Zn-Ni layers with Ni-P deposits increased the time to red rust in salt spray test, the time for white rust formation decreased. The corrosion mechanism of both Zn-Ni and Ni-P (containing small amount of Zn) was preferential dissolution of Zn and the corrosion products were comprised of mainly Zn hydroxychloride and Zn hydroxycarbonate. Also, Ni and P did not take part in the corrosion products. Based on the electrochemical character of the layers and the morphology of the corroded surface, the corrosion mechanism of multilayers was discussed.

Taoist Tai Chi® and Memory Intervention for Individuals with Mild Cognitive Impairment.

PubMed

Fogarty, Jennifer N; Murphy, Kelly J; McFarlane, Bruce; Montero-Odasso, Manuel; Wells, Jennie; Troyer, Angela K; Trinh, Daniel; Gutmanis, Iris; Hansen, Kevin T

2016-04-01

It was hypothesized that a combined Taoist Tai Chi (TTC) and a memory intervention program (MIP) would be superior to a MIP alone in improving everyday memory behaviors in individuals with amnestic mild cognitive impairment (aMCI). A secondary hypothesis was that TTC would improve cognition, self-reported health status, gait, and balance. A total of 48 individuals were randomly assigned to take part in MIP + TTC or MIP alone. The TTC intervention consisted of twenty 90 min sessions. Outcome measures were given at baseline, and after 10 and 22 weeks. Both groups significantly increased their memory strategy knowledge and use, ratings of physical health, processing speed, everyday memory, and visual attention. No preferential benefit was found for individuals in the MIP + TTC group on cognition, gait, or balance measures. Contrary to expectations, TTC exercise did not specifically improve cognition or physical mobility. Explanations for null findings are explored.

SmNiO3/NdNiO3 thin film multilayers

NASA Astrophysics Data System (ADS)

Girardot, C.; Pignard, S.; Weiss, F.; Kreisel, J.

2011-06-01

Rare earth nickelates RENiO3 (RE =rare earth), which attract interest due to their sharp metal-insulator phase transition, are instable in bulk form due to the necessity of an important oxygen pressure to stabilize Ni in its 3+ state of oxidation. Here, we report the stabilization of RE nickelates in [(SmNiO3)t/(NdNiO3)t]n thin film multilayers, t being the thickness of layers alternated n times. Both bilayers and multilayers have been deposited by metal-organic chemical vapor deposition. The multilayer structure and the presence of the metastable phases SmNiO3 and NdNiO3 are evidenced from by x-ray and Raman scattering. Electric measurements of a bilayer structure further support the structural quality of the embedded RE nickelate layers.

NiCo2S4 nanosheet-decorated 3D, porous Ni film@Ni wire electrode materials for all solid-state asymmetric supercapacitor applications.

PubMed

Saravanakumar, Balasubramaniam; Jayaseelan, Santhana Sivabalan; Seo, Min-Kang; Kim, Hak-Yong; Kim, Byoung-Suhk

2017-12-07

Wire type supercapacitors with high energy and power densities have generated considerable interest in wearable applications. Herein, we report a novel NiCo 2 S 4 -decorated 3D, porous Ni film@Ni wire electrode for high performance supercapacitor application. In this work, a facile method is introduced to fabricate a 3D, porous Ni film deposited on a Ni wire as a flexible electrode, followed by decoration with NiCo 2 S 4 as an electroactive material. The fabricated NiCo 2 S 4 -decorated 3D, porous Ni film@Ni wire electrode displays a superior performance with an areal and volumetric capacitance of 1.228 F cm -2 and 199.74 F cm -3 , respectively, at a current density of 0.2 mA cm -1 with a maximum volumetric energy and power density (E V : 6.935 mW h cm -3 ; P V : 1.019 W cm -3 ). Finally, the solid state asymmetric wire type supercapacitor is fabricated using the fabricated NiCo 2 S 4 -decorated 3D, porous Ni film@Ni wire as a positive electrode and N-doped reduced graphene oxide (N-rGO) as a negative electrode and this exhibits good areal and volumetric capacitances of C A : 0.12 F cm -2 and C V : 19.57 F cm -2 with a higher rate capability (92%). This asymmetric wire type supercapacitor demonstrates a low leakage current and self-discharge with a maximum volumetric energy (E V : 5.33 mW h cm -3 ) and power (P V : 855.69 mW cm -3 ) density.

The acceleration intermediate phase (NiS and Ni3S2) evolution by nanocrystallization in Li/NiS2 thermal batteries with high specific capacity

NASA Astrophysics Data System (ADS)

Jin, Chuanyu; Zhou, Lingping; Fu, Licai; Zhu, Jiajun; Li, Deyi; Yang, Wulin

2017-06-01

The intermediate phase of NiS2 is thought to be a bottleneck currently to improve the overall performance of Li/NiS2 thermal batteries because of its low conductivity and close formation enthalpy between NiS2 and the intermediate phase (NiS, Ni3S2, etc). For improving the discharge performances of Li/NiS2 thermal batteries, the nano NiS2 with an average size of 85 ± 5 nm is designated as a cathode material. The electrochemical measurements show that the specific capacity of nano NiS2 cathode is higher than micro NiS2. The nano NiS2 cathode exhibits excellent electrochemical performances with high specific capacities of 794 and 654 mAh g-1 at current density of 0.1 and 0.5 A cm-2 under a cut-off voltage of 0.5 V, respectively. These results show that the rapid intermediate phase evolution from the nanocrystallization can obviously enhance use efficiency of NiS2 and improve discharge performances of thermal batteries.

NiO/NiWO4 Composite Yolk-Shell Spheres with Nanoscale NiO Outer Layer for Ultrasensitive and Selective Detection of Subppm-level p-Xylene.

PubMed

Kim, Tae-Hyung; Kwak, Chang-Hoon; Lee, Jong-Heun

2017-09-20

NiO/NiWO 4 composite yolk-shell spheres with a nanoscale NiO outer layer were prepared using one-pot ultrasonic spray pyrolysis and their gas sensing characteristics were studied. The NiO/NiWO 4 yolk-shell spheres exhibited an extremely high response to 5 ppm p-xylene (ratio of resistance to gas and air = 343.5) and negligible cross-responses to 5 ppm ethanol, ammonia, carbon monoxide, hydrogen, and benzene, whereas pure NiO yolk-shell spheres showed very low responses and selectivity to all the analyte gases. The detection limit for p-xylene was as low as 22.7 ppb. This ultrasensitive and selective detection of p-xylene is attributed to a synergistic catalytic effect between NiO and NiWO 4 , high gas accessibility with large specific surface area, and increased chemiresistive variation due to the formation of a heterojunction. The NiO/NiWO 4 yolk-shell spheres with a thin NiO outer layer can be used to detect subppm-level p-xylene in a highly sensitive and selective manner for monitoring indoor air pollution.

Valence electronic structure of Ni in Ni Si alloys from relative K X-ray intensity studies

NASA Astrophysics Data System (ADS)

Kalayci, Y.; Aydinuraz, A.; Tugluoglu, B.; Mutlu, R. H.

2007-02-01

The Kβ-to-Kα X-ray intensity ratio of Ni in Ni 3Si, Ni 2Si and NiSi has been determined by energy dispersive X-ray fluorescence technique. It is found that the intensity ratio of Ni decreases from pure Ni to Ni 2Si and then increases from Ni 2Si to NiSi, in good agreement with the electronic structure calculations cited in the literature. We have also performed band structure calculations for pure Ni in various atomic configurations by means of linear muffin-tin orbital method and used this data with the normalized theoretical intensity ratios cited in the literature to estimate the 3d-occupation numbers of Ni in Ni-Si alloys. It is emphasized that investigation of alloying effect in terms of X-ray intensity ratios should be carried out for the stoichiometric alloys in order to make reliable and quantitative comparisons between theory and experiment in transition metal alloys.

Silicide formation process of Pt added Ni at low temperature: Control of NiSi2 formation

NASA Astrophysics Data System (ADS)

Ikarashi, Nobuyuki; Masuzaki, Koji

2011-03-01

Transmission electron microscopy (TEM) and ab initio calculations revealed that the Ni-Si reaction around 300 °C is significantly changed by adding Pt to Ni. TEM analysis clarified that NiSi2 was formed in a reaction between Ni thin film (˜1 nm) and Si substrate, while NiSi was formed when Pt was added to the Ni film. We also found that the Ni-adamantane structure, which acts as a precursor for NiSi2 formation around the reaction temperature, was formed in the former reaction but was significantly suppressed in the latter reaction. Theoretical calculations indicated that Pt addition increased stress at the Ni-adamantane structure/Si-substrate interface. The increase in interface stress caused by Pt addition should raise the interface energy to suppress the Ni-adamantane structure formation, leading to NiSi2 formation being suppressed.

Cyclic creep and fatigue of TD-NiCr (thoria-dispersion-strengthened nickel-chromium), TD-Ni, and NiCr sheet at 1200 C

NASA Technical Reports Server (NTRS)

Hirschberg, M. H.; Spera, D. A.; Klima, S. J.

1972-01-01

The resistance of thin TD-NiCr sheet to cyclic deformation was compared with that of TD-Ni and a conventional nickel-chromium alloy. Strains were determined by a calibration technique which combines room-temperature strain gage and deflection measurements with high-temperature deflection measurements. Analyses of the cyclic tests using measured tensile and creep-rupture data indicated that the TD-NiCr and NiCr alloy specimens failed by a cyclic creep mechanism. The TD-Ni specimens, on the other hand, failed by a fatigue mechanism.

Ion irradiation induced defect evolution in Ni and Ni-based FCC equiatomic binary alloys

DOE PAGES

Jin, Ke; Zhang, Yanwen; Bei, Hongbin

2015-09-09

In order to explore the chemical effects on radiation response of alloys with multi-principal elements, defect evolution under Au ion irradiation was investigated in the elemental Ni, equiatomic NiCo and NiFe alloys. Single crystals were successfully grown in an optical floating zone furnace and their (100) surfaces were irradiated with 3 MeV Au ions at fluences ranging from 1 × 10 13 to 5 × 10 15 ions cm –2 at room temperature. The irradiation-induced defect evolution was analyzed by using ion channeling technique. Experiment shows that NiFe is more irradiation-resistant than NiCo and pure Ni at low fluences. Withmore » continuously increasing the ion fluences, damage level is eventually saturated for all materials but at different dose levels. The saturation level in pure Ni appears at relatively lower irradiation fluence than the alloys, suggesting that damage accumulation slows down in the alloys. Here, under high-fluence irradiations, pure Ni has wider damage ranges than the alloys, indicating that defects in pure Ni have high mobility.« less

Influence of annealing temperature on the microstructure and magnetic properties of Ni/NiO core-shell nanowires

NASA Astrophysics Data System (ADS)

Xiang, Wenfeng; Liu, Yuan; Yao, Jiangfeng; Sun, Rui

2018-03-01

Ni/NiO core-shell nanowires (NWs) were synthesized by thermal annealing of Ni NWs and variations in the microstructure, surface morphology, and magnetic properties of the NWs as a function of annealing temperature were investigated. The results showed that the grain size and crystal quality of NiO increased with an increasing annealing temperature. Specially, the effect of annealing temperature was much greater than annealing time for the formation of Ni/NiO NWs during the oxidization process. The total weight gain of the Ni/NiO NWs continuously increased when the annealing temperature was lower than 400 °C and the annealing time was more than 2 h; however, the weight gain of the Ni/NiO NWs was almost constant after annealing for 40 min when the annealing temperature was higher than 500 °C. The thorns on the surface of the Ni/NiO NWs gradually passivated and magnetic properties declined when the annealing temperature was increased from 300 °C to 400 °C. Smooth Ni/NiO NWs with no magnetic properties were prepared when the annealing temperature was over 500 °C. The detail study regarding the formation and evolution of Ni/NiO NWs is of considerable value and may provide useful information regarding the choice of post-treatment parameters for different applications of Ni/NiO NWs.

Tuning the porosity of mesoporous NiO through calcining isostructural Ni-MOFs toward supercapacitor applications

NASA Astrophysics Data System (ADS)

Hou, Xiang-Yang; Yan, Xiao-Li; Wang, Xiao; Zhai, Quan-Guo

2018-07-01

NiO has an unusually high theoretical specific capacitance and possess relatively high electrical conductivity compared to other metal oxides. However, the reported specific capacitance of the NiO-based electrodes is far below the theoretical value up to now. In this paper, three porous NiO materials with different specific surface area were synthesized simply by calcining iso-structural Ni-based MOFs templates. The formation mechanism of NiO was discussed by taking into account the thermal behavior and intrinsic structural features of the Ni-MOFs. Taking advantages of the Ni-MOFs precursors, all prepared NiO compounds are mesoporous and their porosity can be tuned by the structure of MOFs. Specially, due to the high porosity, three NiO exhibited an improved electrochemical performance and the specific discharge capacitances are of 102, 105, and 116 F g-1 at the current density of 1 A g-1, respectively. The specific capacitance of 1-NiO-450 is approximately 93.2% of its maximum value after 3000 cycles, which obviously superior to most of the previously reported NiO electrode materials and suggests their promising applications in supercapacitors.

Ab initio molecular dynamics investigations of low-energy recoil events in Ni and NiCo

DOE PAGES

Liu, Bin; Yuan, Fenglin; Jin, Ke; ...

2015-10-06

Low-energy recoil events in pure Ni and the equiatomic NiCo alloy are studied using ab initio molecular dynamics simulations. We found that the threshold displacement energies are strongly dependent on orientation and weakly dependent on composition. The minimum threshold displacement energies are along the [1 1 0] direction in both pure Ni and the NiCo alloy. Compared to pure Ni, the threshold displacement energies increase slightly in the NiCo alloy due to stronger bonds in the alloy, irrespective of the element type of the PKA. A single Ni interstitial occupying the center of a tetrahedron formed by four Ni atomsmore » and a <1 0 0> split interstitial is produced in pure Ni by the recoils, while only the <1 0 0> split interstitial is formed in the NiCo alloy. Compared to the replacement sequences in pure Ni, anti-site defect sequences are observed in the alloy, which have high efficiency for both producing defects and transporting energy outside of the cascade core. These results provide insights into energy transfer processes occurring in equiatomic alloys under irradiation.« less

Synthesis and characterization of T[Ni(CN){sub 4}].2pyz with T=Fe, Ni; pyz=pyrazine: Formation of T-pyz-Ni bridges

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lemus-Santana, A.A.; Rodriguez-Hernandez, J.; Institute of Materials Science and Technology, University of Havana

2011-08-15

The formation of T-pyz-Ni bridges (pyz=pyrazine) in the T[Ni(CN){sub 4}].2pyz series is known for T=Mn, Zn, Cd and Co but not with T=Fe, Ni. In this contribution the existence of such bridges also for T=Fe, Ni is discussed. The obtained pillared solids, T[Ni(CN){sub 4}].2pyz, were characterized from XRD, TG, UV-Vis, IR, Raman, Moessbauer and magnetic data. Their crystal structures were refined in the orthorhombic Pmna space group from XRD powder patterns. The structural behavior of these solids on cooling down to 77 K was also studied. In the 180-200 K temperature range the occurrence of a structural transition to amore » monoclinic structure (P2{sub 1}/c space group) was observed. No temperature induced spin transition was observed for Fe[Ni(CN){sub 4}].2pyz. The iron (II) was found to be in high spin electronic state and this configuration is preserved on cooling down to 2 K. The magnetic data indicate the occurrence of a low temperature weak anti-ferromagnetic interaction between T metal centers within the T[Ni(CN){sub 4}] layer. In the paramagnetic region for Ni[Ni(CN){sub 4}].2pyz, a reversible temperature induced spin transition for the inner Ni atom was detected. - Graphical abstract: Rippled sheets structure for the pillared solids T[Ni(CN){sub 4}].2pyz. The pyrazine molecule is found forming T-pyz-Ni bridges between neighboring layers. Highlights: > Pillared 2D solids. > Inorganic-organic solids. > Assembling of molecular blocks. > From 1D and 2D building blocks to 3D solids.« less

Comparative study of the dissociation energies of Ni2 and Ni2(+)

NASA Technical Reports Server (NTRS)

Bauschlicher, Charles W., Jr.; Partridge, Harry; Langhoff, Stephen R.

1992-01-01

Computations at the internally contracted averaged coupled-pair-functional level of theory yield a dissociation energy (Do) for Ni2(+) that is 0.17 eV larger than that of Ni2. This finding is consistent with the collision-induced dissociation experiments of Lian, Su, and Armentrout, but rules out the results from the resonant two-photon dissociation experiments of Lessen and Brucat, which predict that the Do value of Ni2(+) is about 1 eV larger than that of Ni2.

Local lattice distortion in NiCoCr, FeCoNiCr and FeCoNiCrMn concentrated alloys investigated by synchrotron X-ray diffraction

DOE PAGES

Tong, Yang; Jin, Ke; Bei, Hongbin; ...

2018-05-26

Severe lattice distortion is presumptively considered as a core effect of high-entropy alloys, but quantitative measurements are still missing. Here, we demonstrate that the lattice distortion in high-entropy alloys can be quantitatively analyzed based on pair distribution function obtained from synchrotron X-ray diffraction. By applying this method to equiatomic NiCoCr, FeCoNiCr and FeCoNiCrMn concentrated alloys, we found that the local lattice distortion in the NiCoCr (0.23%) and FeCoNiCrMn (0.24%) alloys are comparable while negligible in the FeCoNiCr alloy (0.04%). Furthermore, the origin of local lattice distortion in the NiCoCr and FeCoNiCrMn concentrated alloys was discussed.

Local lattice distortion in NiCoCr, FeCoNiCr and FeCoNiCrMn concentrated alloys investigated by synchrotron X-ray diffraction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tong, Yang; Jin, Ke; Bei, Hongbin

Severe lattice distortion is presumptively considered as a core effect of high-entropy alloys, but quantitative measurements are still missing. Here, we demonstrate that the lattice distortion in high-entropy alloys can be quantitatively analyzed based on pair distribution function obtained from synchrotron X-ray diffraction. By applying this method to equiatomic NiCoCr, FeCoNiCr and FeCoNiCrMn concentrated alloys, we found that the local lattice distortion in the NiCoCr (0.23%) and FeCoNiCrMn (0.24%) alloys are comparable while negligible in the FeCoNiCr alloy (0.04%). Furthermore, the origin of local lattice distortion in the NiCoCr and FeCoNiCrMn concentrated alloys was discussed.

Stress-induced solid-state amorphization of nanocrystalline Ni and NiZr investigated by atomistic simulations

NASA Astrophysics Data System (ADS)

Meraj, Md.; Deng, Chuang; Pal, Snehanshu

2018-01-01

In this study, the feasibility of stress induced solid-state amorphization (SSA) of nanocrystalline (NC) Ni and NiZr alloys having ˜10 nm grain size has been investigated under constant tensile load (uniaxial and triaxial) via molecular dynamics simulations. In order to track the structural evaluation in both NC Ni and NiZr alloys during the SSA process, various types of analysis have been used, including simulated X-ray diffraction, centro-symmetry parameter, Voronoi cluster, common neighbor analysis, and radial distribution function. It is found that SSA in both NC Ni and NiZr alloys can only be achieved under triaxial loading conditions, and the hydrostatic tensile stress required for SSA is significantly lower when at. % Zr is increased in the NC NiZr alloy. Specifically, SSA in NC Ni and Ni-5 at. % Zr alloy was observed only when the temperature and hydrostatic tensile stress reached 800 K and 6 GPa, while SSA could occur in NC Ni-10 at. % Zr alloy under just 2 GPa of hydrostatic tensile stress at 300 K.

Efficacy of rehabilitation with Tai Ji Quan in an Italian cohort of patients with Fibromyalgia Syndrome.

PubMed

Maddali Bongi, Susanna; Paoletti, Gianluca; Calà, Michael; Del Rosso, Angela; El Aoufy, Khadija; Mikhaylova, Svetlana

2016-08-01

Fibromyalgia Syndrome (FMS) is characterized by musculoskeletal pain, muscle tenderness leading to disability, impaired quality of life (QoL), fatigue and it is accompanied by sleep disorders and psychological distress. Mind body therapies (MBT), such as Tai Ji Quan (TJQ), use different techniques to facilitate the ability of the mind to influence disease characteristics and symptoms. Some studies showed that TJQ, in patients with rheumatic diseases, particularly FMS, improved QoL, disability and psychological distress. To evaluate the efficacy of TJQ on disability, QoL, fatigue, sleep and psychological distress in an Italian cohort of FMS patients. We enrolled 44 FMS patients: 22 patients (Experimental Group) participated to a course of Tai Ji Quan style of (2/week for 16 weeks); 22 patients (Control Group) participated to an educational course about FMS (2/week for 16 weeks). At baseline (T0) and at the end of treatment (T1), patients were assessed for disability [Fibromyalgia Impact Questionnaire (FIQ), Health Assessment Questionnaire (HAQ)], Quality of Life [Short-Form 36 (SF36)], fatigue [Functional Assessment of Chronic Illness-Fatigue (FACIT-F)], pain [Widespread Pain Index (WPI)], tenderness [Tender Points (TP)], Sleep Quality [Pittsburgh Sleep Quality Index (PSQI)] and mood disorders [Hospital Anxiety and Depression Scale (HADS)]. At T1 versus T0, patients of the Experimental Group showed a significant improvement in FIQ, FACIT, SF36 (Summary Physical Index, Physical activity, physical role, bodily pain, general health, vitality, emotional role limitations), in WPI, TP, PSQI (total, sleep duration, and sleep disturbance) and HADS (total score and anxiety subscale), while Patients in the Control Group did not improve in any parameter. In FMS patients TJQ, if performed by an expert physiotherapist, should be regarded as an effective rehabilitation method. Copyright © 2016 Elsevier Ltd. All rights reserved.

Oxide Scales Formed on NiTi and NiPtTi Shape Memory Alloys

NASA Technical Reports Server (NTRS)

Smialek, James L.; Garg, Anita; Rogers, Richard B.; Noebe, Ronald D.

2011-01-01

Ni-49Ti and Ni-30Pt-50Ti (at.%) shape memory alloys were oxidized isothermally in air over the temperature range of 500 to 900 C. The microstructure, composition, and phase content of the scales were studied by SEM, EDS, XRD, and metallography. Extensive plan view SEM/EDS identified various features of intact or spalled scale surfaces. The outer surface of the scale was a relatively pure TiO2 rutile structure, typified by a distinct highly striated and faceted crystal morphology. Crystal size increased significantly with temperature. Spalled regions exhibited some porosity and less distinct features. More detailed information was obtained by correlation of SEM/EDS studies of 700 C/100 hr cross-sections with XRD analyses of serial or taper-polishing of plan surfaces. Overall, multiple layers exhibited graded mixtures of NiO, TiO2, NiTiO3, Ni(Ti) or Pt(Ni,Ti) metal dispersoids, Ni3Ti or Pt3Ti depletion zones, and substrate, in that order. The NiTi alloy contained a 3 at.% Fe impurity that appeared in embedded localized Fe-Ti-rich oxides, while the NiPtTi alloy contained a 2 v/o dispersion of TiC that appeared in lower layers. The oxidation kinetics of both alloys (in a previous report) indicated parabolic growth and an activation energy (250 kJ/mole) near those reported in other Ti and NiTi studies. This is generally consistent with TiO2 existing as the primary scale constituent, as described here.

The Mind Body-Wellness in Supportive Housing (Mi-WiSH) study: Design and rationale of a cluster randomized controlled trial of Tai Chi in senior housing.

PubMed

Wayne, Peter M; Gagnon, Margaret M; Macklin, Eric A; Travison, Thomas G; Manor, Bradley; Lachman, Margie; Thomas, Cindy P; Lipsitz, Lewis A

2017-09-01

Supporting the health of growing numbers of frail older adults living in subsidized housing requires interventions that can combat frailty, improve residents' functional abilities, and reduce their health care costs. Tai Chi is an increasingly popular multimodal mind-body exercise that incorporates physical, cognitive, social, and meditative components in the same activity and offers a promising intervention for ameliorating many of the conditions that lead to poor health and excessive health care utilization. The Mind Body-Wellness in Supportive Housing (Mi-WiSH) study is an ongoing two-arm cluster randomized, attention-controlled trial designed to examine the impact of Tai Chi on functional indicators of health and health care utilization. We are enrolling participants from 16 urban subsidized housing facilities (n=320 participants), conducting the Tai Chi intervention or education classes and social calls (attention control) in consenting subjects within the facilities for one year, and assessing these subjects at baseline, 6months, and 1year. Physical function (quantified by the Short Physical Performance Battery), and health care utilization (emergency visits, hospitalizations, skilled nursing and nursing home admissions), assessed at 12months are co-primary outcomes. Our discussion highlights our strategy to balance pragmatic and explanatory features into the study design, describes efforts to enhance site recruitment and participant adherence, and summarizes our broader goal of post study dissemination if effectiveness and cost-effectiveness are demonstrated, by preparing training and protocol manuals for use in housing facilities across the U.S. Copyright © 2017 Elsevier Inc. All rights reserved.

Length-dependent corrosion behavior, Ni2+ release, cytocompatibility, and antibacterial ability of Ni-Ti-O nanopores anodically grown on biomedical NiTi alloy.

PubMed

Hang, Ruiqiang; Liu, Yanlian; Bai, Long; Zhang, Xiangyu; Huang, Xiaobo; Jia, Husheng; Tang, Bin

2018-08-01

In the present work, nickel-titanium-oxygen nanopores with different length (0.55-114 μm) were anodically grown on nearly equiatomic nickel-titanium (NiTi) alloy. Length-dependent corrosion behavior, nickel ion (Ni 2+ ) release, cytocompatibility, and antibacterial ability were investigated by electrochemical, analytical chemistry, and biological methods. The results show constructing nanoporous structure on the NiTi alloy improve its corrosion resistance. However, the anodized samples release more Ni 2+ than that of the bare NiTi alloy, suggesting chemical dissolution of the nanopores rather than electrochemical corrosion governs the Ni 2+ release. In addition, the Ni 2+ release amount increases with nanopore length. The anodized samples show good cytocompatibility when the nanopore length is <11 μm. Encouragingly, the length scale covers the one (1-11 μm) that the nanopores showing favorable antibacterial ability. Consequently, the nanopores with length in the range of 1-11 μm are promising as coatings of biomedical NiTi alloy for anti-infection, drug delivery, and other desirable applications. Copyright © 2018 Elsevier B.V. All rights reserved.

Peculiarities of thermoelectric half-Heusler phase formation in Gd-Ni-Sb and Lu-Ni-Sb ternary systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Romaka, V.V., E-mail: romakav@lp.edu.ua; Romaka, L.; Horyn, A.

The phase equilibria in the Gd–Ni–Sb and Lu-Ni-Sb ternary systems were studied at 873 K by X-ray and metallographic analyses in the whole concentration range. The interaction of the elements in the Gd–Ni–Sb system results the formation of five ternary compounds at investigated temperature: Gd{sub 5}Ni{sub 2}Sb (Mo{sub 5}SiB{sub 2}-type), Gd{sub 5}NiSb{sub 2} (Yb{sub 5}Sb{sub 3}-type), GdNiSb (MgAgAs-type), Gd{sub 3}Ni{sub 6}Sb{sub 5} (Y{sub 3}Ni{sub 6}Sb{sub 5}-type), and GdNi{sub 0.72}Sb{sub 2} (HfCuSi{sub 2}-type). At investigated temperature the Lu-Ni-Sb system is characterized by formation of the LuNiSb (MgAgAs-type), Lu{sub 5}Ni{sub 2}Sb (Mo{sub 5}SiB{sub 2}-type), and Lu{sub 5}Ni{sub 0.56}Sb{sub 2.44} (Yb{sub 5}Sb{sub 3}-type)more » compounds. The disordering in the crystal structure of half-Heusler GdNiSb and LuNiSb was revealed by EPMA and studied by means of Rietveld refinement and DFT modeling. The performed electronic structure calculations are in good agreement with electrical transport property studies. - Graphical abstract: Crystal structure model and electron localization function of Lu{sub 5}Ni{sub 2}Sb. Display Omitted - Highlights: • Gd-Ni-Sb and Lu-Ni-Sb phase diagrams were constructed at 873 K. • GdNiSb and LuNiSb are characterized by disordered crystal structure. • Crystal structure optimization with DFT calculations confirmed crystal structure disorder in GdNiSb and LuNiSb.« less

Effects of Tai Chi Training on Antioxidant Capacity in Pre- and Postmenopausal Women

PubMed Central

Palasuwan, Attakorn; Suksom, Daroonwan; Margaritis, Irène; Soogarun, Suphan; Rousseau, Anne-Sophie

2011-01-01

The risk of oxidative stress-related metabolic diseases increases with menopause and physical inactivity. We hypothesized that an 8-week Tai Chi (TC) training program (2 sessions in class; 2 sessions at home; 1-1:15/session) would improve antioxidant capacity and reduce cardiovascular risks in both pre- (n = 8) and postmenopausal (n = 7) sedentary women. Selected measures of physical fitness and blood parameters were analyzed before and after the program. Besides the well-known effects of TC on balance, flexibility, and maximum leg extensor strength, TC (1) increased erythrocyte glutathione peroxidase activity—an aerobic training-responsive antioxidant enzyme—and plasma total antioxidant status and (2) decreased plasma total homocysteine, a cardiovascular risk marker. In addition to being a low-velocity, low-impact, and relatively safe, TC is a suitable physical activity design for pre- and postmenopausal women to increase antioxidant defenses. Investigating breathing effects during TC movements would be an interesting area for further research in diseases prevention. PMID:21584229

Effects of tai chi training on antioxidant capacity in pre- and postmenopausal women.

PubMed

Palasuwan, Attakorn; Suksom, Daroonwan; Margaritis, Irène; Soogarun, Suphan; Rousseau, Anne-Sophie

2011-04-11

The risk of oxidative stress-related metabolic diseases increases with menopause and physical inactivity. We hypothesized that an 8-week Tai Chi (TC) training program (2 sessions in class; 2 sessions at home; 1-1:15/session) would improve antioxidant capacity and reduce cardiovascular risks in both pre- (n = 8) and postmenopausal (n = 7) sedentary women. Selected measures of physical fitness and blood parameters were analyzed before and after the program. Besides the well-known effects of TC on balance, flexibility, and maximum leg extensor strength, TC (1) increased erythrocyte glutathione peroxidase activity-an aerobic training-responsive antioxidant enzyme-and plasma total antioxidant status and (2) decreased plasma total homocysteine, a cardiovascular risk marker. In addition to being a low-velocity, low-impact, and relatively safe, TC is a suitable physical activity design for pre- and postmenopausal women to increase antioxidant defenses. Investigating breathing effects during TC movements would be an interesting area for further research in diseases prevention.

On the Ni-Ion release rate from surfaces of binary NiTi shape memory alloys

NASA Astrophysics Data System (ADS)

Ševčíková, Jana; Bártková, Denisa; Goldbergová, Monika; Kuběnová, Monika; Čermák, Jiří; Frenzel, Jan; Weiser, Adam; Dlouhý, Antonín

2018-01-01

The study is focused on Ni-ion release rates from NiTi surfaces exposed in the cell culture media and human vascular endothelial cell (HUVEC) culture environments. The NiTi surface layers situated in the depth of 70 μm below a NiTi oxide scale are affected by interactions between the NiTi alloys and the bio-environments. The finding was proved with use of inductively coupled plasma mass spectrometry and electron microscopy experiments. As the exclusive factor controlling the Ni-ion release rates was not only thicknesses of the oxide scale, but also the passivation depth, which was two-fold larger. Our experimental data strongly suggested that some other factors, in addition to the Ni concentration in the oxide scale, admittedly hydrogen soaking deep below the oxide scale, must be taken into account in order to rationalize the concentrations of Ni-ions released into the bio-environments. The suggested role of hydrogen as the surface passivation agent is also in line with the fact that the Ni-ion release rates considerably decrease in NiTi samples that were annealed in controlled hydrogen atmospheres prior to bio-environmental exposures.

Simple solution-combustion synthesis of Ni-NiO@C nanocomposites with highly electrocatalytic activity for methanol oxidation

NASA Astrophysics Data System (ADS)

Yu, Jie; Ni, Yonghong; Zhai, Muheng

2018-01-01

Transition metal and its oxide composite nanomaterials are attracting increasing research interest due to their superior properties and extensive applications in many fields. In this paper, Ni-NiO@C nanocomposites were successfully synthesized in one step via a simple solution-combustion route, employing NiCl2 as the Ni source, oxygen in the atmosphere as the oxygen source, and ethanol as the solvent. The final product was characterized by powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS), (high resolution) transmission electron microscopy (TEM/HRTEM), and Raman spectra. N2 gas sorption-desorption experiments uncovered that the BET surface area of Ni-NiO@C nanocomposites reached 161.9 m2 g-1, far higher than 34.2 m2 g-1 of Ni-NiO. The electrochemical measurement showed that the as-produced Ni-NiO@C nanocomposites presented better catalytic activity for the electro-oxidation of methanol than Ni-NiO and NiO, which provides a new catalyst selection for the electro-oxidation of methanol.

Prevalence and Antimicrobial Resistance of Salmonella Isolates Recovered from Retail Pork in Major Village Markets in Tai'an Region, China.

PubMed

Miao, Zengmin; Li, Song; Qin, Kun; Zhou, Yufa

2017-10-01

The current study was undertaken to evaluate Salmonella contamination in retail pork at major village markets of the Tai'an region, China. In total, 200 retail pork samples were collected from four village markets between June 2015 and February 2016, of which 69 samples (34.5%) were determined to be positive for Salmonella. Eleven serotypes were identified from the 69 Salmonella isolates, and Salmonella Derby was the most common (18 of 69, 26.1%), followed by Typhimurium (17 of 69, 24.6%) and Meleagridis (11 of 69, 15.9%). Antimicrobial susceptibility testing showed that antimicrobial resistance against tetracycline was the most prevalent (42 of 69, 60.9%), but antimicrobial resistance against both ceftriaxone and cefotaxime was 1.4% (1 of 69) and 2.9% (2 of 69), respectively. Multilocus sequence typing revealed that the 69 Salmonella isolates were divided into 11 sequence types (STs), among which ST40 (18 of 69, 26.1%) was the most common, followed by ST34 (15 of 69, 21.7%) and ST64 (13 of 69, 18.8%). Collectively, retail pork at village markets in the Tai'an region has a high Salmonella contamination rate, and these isolates exhibit broad-spectrum antimicrobial resistance. However, the absence of a dominant ST demonstrates that the Salmonella isolates from retail pork may be of diverse origins.

Thermoelectric properties of (DyNiSn)1-x(DyNiSb)x composite

NASA Astrophysics Data System (ADS)

Synoradzki, Karol; Ciesielski, Kamil; Kępiński, Leszek; Kaczorowski, Dariusz

2018-05-01

High temperature thermoelectric properties of bulk and ball-milled cold-pressed (DyNiSn)1-x(DyNiSb)x composite materials have been studied. For bulk pure DyNiSn and DyNiSb samples the Seebeck coefficient reaches - 5.5 μV/K at 480 K and 120 μV/K at 540 K, respectively. Composite materials show metallic-like electrical resistivity and positive sign of Seebeck coefficient with values up to 50 times higher than in pure DyNiSn compound at 1000 K. Only for the sample with x = 0.47, the ball-milling drives to increase of Seebeck coefficient of about 37% at 650 K.

Effects of two-temperature model on cascade evolution in Ni and NiFe

DOE PAGES

Samolyuk, German D.; Xue, Haizhou; Bei, Hongbin; ...

2016-07-05

We perform molecular dynamics simulations of Ni ion cascades in Ni and equiatomic NiFe under the following conditions: (a) classical molecular dynamics (MD) simulations without consideration of electronic energy loss, (b) classical MD simulations with the electronic stopping included, and (c) using the coupled two-temperature MD (2T-MD) model that incorporates both the electronic stopping and the electron-phonon interactions. Our results indicate that the electronic effects are more profound in the higher-energy cascades, and that the 2T-MD model results in a smaller amount of surviving damage and smaller defect clusters, while less damage is produced in NiFe than in Ni.

Superconductivity in Bi/Ni bilayer system: Clear role of superconducting phases found at Bi/Ni interface

NASA Astrophysics Data System (ADS)

Liu, L. Y.; Xing, Y. T.; Merino, I. L. C.; Micklitz, H.; Franceschini, D. F.; Baggio-Saitovitch, E.; Bell, D. C.; Solórzano, I. G.

2018-01-01

Bi/Ni bilayers with varying Bi and Ni layer thicknesses have been prepared by (a) pulsed-laser deposition (PLD) at 300 K and (b) thermal evaporation at 4.2 K. A two-step superconducting transition appears on the electrical transport measurements in the samples prepared by PLD. High-resolution transmission and scanning transmission electron microscopy, supported by energy-dispersive x-ray spectroscopy (EDXS) analysis, reveal that two superconducting intermetallic alloys, namely NiBi and NiBi3, are formed by interdiffusion, if the bilayers are prepared at 300 K. The Tc of the two phases behaves very differently in an external magnetic field and the upper critical magnetic fields at zero temperature [Bc 2(0 ) ] were estimated as 1.1 and 7.4 T, respectively. The lower value corresponds to the Bc 2(0) of NiBi3 phase and the higher one is supposed to be of NiBi. These alloys are responsible for the superconductivity and the two-step transition appearing in the Bi/Ni bilayer system. Surprisingly, the Bi-rich phase (NiBi3) is formed near the Ni layer, while the Ni-rich phase (NiBi) is formed far from the Ni layer. The EDXS analysis at nanometer scale clearly shows an unusual increase of Ni concentration near the interface of Bi/substrate. The limited thickness of Bi layer in the interdiffusion process results in an unexpected distribution of Ni concentration. Samples prepared at 4.2 K after annealing at 300 K do not show any superconductivity, which indicates that a nonepitaxial Bi/Ni interface does not induce superconductivity in the case interdiffusion does not occur. These results offer a deeper understanding of the superconductivity in the Bi/Ni bilayer system.

Cold Spray Deposition of Ni and WC-Reinforced Ni Matrix Composite Coatings

NASA Astrophysics Data System (ADS)

Alidokht, S. A.; Vo, P.; Yue, S.; Chromik, R. R.

2017-12-01

Ni-WC composites are ideal protective coatings against wear and are often fabricated using laser cladding and thermal spray processes, but the high temperatures of these processes result in decarburization, which deteriorates the performance of the coating. Cold spray has the potential to deposit Ni-WC composite coatings and retain the composition of the initial WC feedstock. However, the insignificant plastic deformation of hard WC particles makes it difficult to build up a high WC content coating by cold spray. By using three different WC powder sizes, the effect of feedstock powder size on WC retention was tested. To improve WC retention, a WC/Ni composite powder in mixture with Ni was also sprayed. Microstructural characterization, including the deformed structure of Ni splats, retention, distribution, and fragmentation of WC, was performed by scanning electron microscopy. An improvement in WC retention was achieved using finer WC particles. Significant improvement in WC particles retention was achieved using WC/Ni composite powder, with the WC content in the coating being close to that of the feedstock.

He behavior in Ni and Ni-based equiatomic solid solution alloy

NASA Astrophysics Data System (ADS)

Yan, Zhanfeng; Liu, Shaoshuai; Xia, Songqin; Zhang, Yong; Wang, Yugang; Yang, Tengfei

2018-07-01

In the current work, pure nickel (99.99 wt.%) and Ni-containing single phase equiatomic solid solution alloy Fe-Co-Cr-Ni were irradiated with 190 keV He ions at room temperature with different fluences and He behavior in both materials are compared. At 1 × 1017 cm-2, TEM observation reveals that only isolated and small He bubbles (1-2 nm) are formed in Fe-Co-Cr-Ni alloy while many small suspected "string"-like He bubbles are observed in nickel at the concentration peak region (5.5 at.%). When the fluence is increased to 5 × 1017 cm-2, average bubble size in nickel increases to ∼8 nm which is almost equal to that in Fe-Co-Cr-Ni, but a higher bubble density is observed in nickel. At the highest dose of 1 × 1018 cm-2, numerous surface blisters and exfoliations occur in nickel which are consistent with TEM observation, while the Fe-Co-Cr-Ni alloy only shows a slight surface blister. Bubble coarsening upon annealing at 500 °C (2 h) is observed at 5 × 1017 cm-2 in both alloys, but a significant larger bubble growth is observed in nickel, suggesting a relatively better resistance to He bubble growth for Fe-Co-Cr-Ni alloy.

H-Phase Precipitation and Martensitic Transformation in Ni-rich Ni-Ti-Hf and Ni-Ti-Zr High-Temperature Shape Memory Alloys

NASA Astrophysics Data System (ADS)

Evirgen, A.; Pons, J.; Karaman, I.; Santamarta, R.; Noebe, R. D.

2018-03-01

The distributions of H-phase precipitates in Ni50.3Ti29.7Hf20 and Ni50.3Ti29.7Zr20 alloys formed by aging treatments at 500 and 550 °C or slow furnace cooling and their effects on the thermal martensitic transformation have been investigated by TEM and calorimetry. The comparative study clearly reveals faster precipitate-coarsening kinetics in the NiTiZr alloy than in NiTiHf. For precipitates of a similar size of 10-20 nm in both alloys, the martensite plates in Ni50.3Ti29.7Zr20 have larger widths and span a higher number of precipitates compared with the Ni50.3Ti29.7Hf20 alloy. However, for large H-phase particles with hundreds of nm in length, no significant differences in the martensitic microstructures of both alloy systems have been observed. The martensitic transformation temperatures of Ni50.3Ti29.7Hf20 are 80-90 °C higher than those of Ni50.3Ti29.7Zr20 in the precipitate-free state and in the presence of large particles of hundreds on nm in length, but this difference is reduced to only 10-20 °C in samples with small H-phase precipitates. The changes in the transformation temperatures are consistent with the differences in the precipitate distributions between the two alloy systems observed by TEM.

Transformation to Ni5Al3 in a 63.0 at. pct Ni-Al alloy

NASA Technical Reports Server (NTRS)

Khadkikar, P. S.; Locci, I. E.; Vedula, K.; Michal, G. M.

1993-01-01

Microstructures of 63 at. pct P/M Ni-Al alloys with a composition close to the stoichiometry of the Ni5Al3 phase were investigated using homogenized and quenched specimens aged at low temperatures for various times. Results of analyses of XRD data and electron microscopy observations were used for quantitative phase analysis, performed to calculate the (NiAl + Ni5Al3)/Ni5Al3 phase boundary locations. The measured lattice parameters of Ni5Al3 phase formed at 823, 873, and 923 K indicated an increase in tetragonality of the phase with increasing nickel content.

Cavitation resistance of surface composition "Steel-Ni-TiNi-TiNiZr-cBNCo", formed by High-Velocity Oxygen-Fuel spraying

NASA Astrophysics Data System (ADS)

Blednova, Zh. M.; Dmitrenko, D. V.; Balaev, E. U. O.

2018-01-01

The object of the study is a multilayered surface composition "Steel - a Multicomponent material with Shape Memory Effect - a wear-resistant layer" under conditions of cavitation effects in sea water. Multicomponent TiNi-based coatings with addition of alloying elements such as Zr in an amount up to 10% mass, allow to create a composite material with a gradient of properties at the interface of layers, which gives new properties to coatings and improves their performance significantly. The use of materials with shape memory effect (SME) as surface layers or in the composition of surface layered compositions allows to provide an effective reaction of materials to the influence of external factors and adaptation to external influences. The surface composite layer cBN-10%Co has high hardness and strength, which ensures its resistance to shock cyclic influences of collapsing caverns. The increased roughness of the surface of a solid surface composite in the form of strong columnar structures ensures the crushing of vacuum voids, redistributing their effect on the entire surface, and not concentrating them in certain zones. In addition, the gradient structure of the multilayer composite coating TiNi-Ti33Ni49Zr18-cBN-10%Co Co makes it possible to create conditions for the relaxation of stresses created by the variable impact load of cavitation caverns and the manifestation of compensating internal forces due to thermo-elastic martensitic transformations of SME materials. The cavitation resistance of the coating TiNi-Ti33Ni49Zr18-cBN-10%Co according to the criterion of mass wear is 15-20 times higher than that of the base material without coating and 10-12 times higher than that of the TiNi-TiNiZr coating. The proposed architecture of the multifunctional gradient composition, "steel-Ni-TiNi- Ti33Ni49Zr18-cBN-10%Co", each layer of which has its functional purpose, allows to increase the service life of parts operating under conditions of cavitation-fatigue loading in

Tai Chi and vestibular rehabilitation improve vestibulopathic gait via different neuromuscular mechanisms: Preliminary report

PubMed Central

McGibbon, Chris A; Krebs, David E; Parker, Stephen W; Scarborough, Donna M; Wayne, Peter M; Wolf, Steven L

2005-01-01

Background Vestibular rehabilitation (VR) is a well-accepted exercise program intended to remedy balance impairment caused by damage to the peripheral vestibular system. Alternative therapies, such as Tai Chi (TC), have recently gained popularity as a treatment for balance impairment. Although VR and TC can benefit people with vestibulopathy, the degree to which gait improvements may be related to neuromuscular adaptations of the lower extremities for the two different therapies are unknown. Methods We examined the relationship between lower extremity neuromuscular function and trunk control in 36 older adults with vestibulopathy, randomized to 10 weeks of either VR or TC exercise. Time-distance measures (gait speed, step length, stance duration and step width), lower extremity sagittal plane mechanical energy expenditures (MEE), and trunk sagittal and frontal plane kinematics (peak and range of linear and angular velocity), were measured. Results Although gait time-distance measures were improved in both groups following treatment, no significant between-groups differences were observed for the MEE and trunk kinematic measures. Significant within groups changes, however, were observed. The TC group significantly increased ankle MEE contribution and decreased hip MEE contribution to total leg MEE, while no significant changes were found within the VR group. The TC group exhibited a positive relationship between change in leg MEE and change in trunk velocity peak and range, while the VR group exhibited a negative relationship. Conclusion Gait function improved in both groups consistent with expectations of the interventions. Differences in each group's response to therapy appear to suggest that improved gait function may be due to different neuromuscular adaptations resulting from the different interventions. The TC group's improvements were associated with reorganized lower extremity neuromuscular patterns, which appear to promote a faster gait and reduced

Electrodeposition of Ni and CeO₂/Ni Nanotubes for Hydrogen Evolution Reaction Electrode.

PubMed

Du, Xiaoqing; Yang, Yumeng; Yi, Chenxi; Chen, Yu; Cai, Chao; Zhang, Zhao

2018-07-01

Ni NTs and CeO2-Ni nanotubes (NTs) have been prepared by galvanostatic electrodeposition in anodic aluminum oxide (AAO) Templates. Scanning electron microscope (SEM), high resolution transmission electron microscopy (HRTEM), energy dispersive X-ray spectroscopic (EDS) and X-ray Diffraction (XRD) are used to characterize the prepared NTs. The results showed that the preparation process of CeO2-Ni NTs was accompanied by the formation of many new phases CeNix (x = 1, 2, 3.5 or 5) and preferential orientation crystal face of Ni in CeO2-Ni NTs is 〈111〉, which is different from that Ni 〈200〉 in Ni NTs. Then linear scan voltammetry (LSV) is applied to test the electrocatalytic activity for hydrogen revolution reaction (HER) of the two electrodes in 1 M NaCl aqueous solution and find that both of the two materials exhibited good performance. Finally, the kinetics analyses from the HER process showed that Tafel slope b was mainly dependent on phase composition and electric conductivity of the electrode, while j0 was mainly dependent on its real specific surface area.

A scanning tunnelling microscopy study of C and N adsorption phases on the vicinal Ni(100) surfaces Ni(810) and Ni(911)

NASA Astrophysics Data System (ADS)

Driver, S. M.; Toomes, R. L.; Woodruff, D. P.

2016-04-01

The influence of N and C chemisorption on the morphology and local structure of nominal Ni(810) and Ni(911) surfaces, both vicinal to (100) but with [001] and [ 01 1 bar ] step directions, respectively, has been investigated using scanning tunnelling microscopy (STM) and low energy electron diffraction. Ni(911) undergoes substantial step bunching in the presence of both adsorbates, with the (911)/N surface showing (411) facets, whereas for Ni(810), multiple steps 2-4 layers high are more typical. STM atomic-scale images show the (2 × 2)pg 'clock' reconstruction on the (100) terraces of the (810) surfaces with both C and N, although a second c(2 × 2) structure, most readily reconciled with a 'rumpling' reconstruction, is also seen on Ni(810)/N. On Ni(911), the clock reconstruction is not seen on the (100) terraces with either adsorbate, and these images are typified by protrusions on a (1 × 1) mesh. This absence of clock reconstruction is attributed to the different constraints imposed on the lateral movements of the surface Ni atoms adjacent to the up-step edge of the terraces with a [ 01 1 bar ] step direction.

Ag-nanoparticles-decorated NiO-nanoflakes grafted Ni-nanorod arrays stuck out of porous AAO as effective SERS substrates.

PubMed

Zhou, Qitao; Meng, Guowen; Huang, Qing; Zhu, Chuhong; Tang, Haibin; Qian, Yiwu; Chen, Bin; Chen, Bensong

2014-02-28

NiO-nanoflakes (NiO-NFs) grafted Ni-nanorod (Ni-NR) arrays stuck out of the porous anodic aluminum oxide (AAO) template are achieved by a combinatorial process of AAO-confined electrodeposition of Ni-NRs, selectively etching part of the AAO template to expose the Ni-NRs, wet-etching the exposed Ni-NRs in ammonia to obtain Ni(OH)2-NFs grafted onto the cone-shaped Ni-NRs, and annealing to transform Ni(OH)2-NFs in situ into NiO-NFs. By top-view sputtering, Ag-nanoparticles (Ag-NPs) are decorated on each NiO-NFs grafted Ni-NR (denoted as NiO-NFs@Ni-NR). The resultant Ag-NPs-decorated NiO-NFs@Ni-NR (denoted as Ag-NPs@NiO-NFs@Ni-NR) arrays exhibit not only strong surface-enhanced Raman scattering (SERS) activity but also reproducible SERS-signals over the whole array. It is demonstrated that the strong SERS-activity is mainly ascribed to the high density of sub-10 nm gaps (hot spots) between the neighboring Ag-NPs, the semiconducting NiO-NFs induced chemical enhancement effect, and the lightning rod effect of the cone-shaped Ni-NRs. The three-level hierarchical nanostructure arrays stuck out of the AAO template can be utilized to probe polychlorinated biphenyls (PCBs, a kind of global environmental hazard) with a concentration as low as 5 × 10(-6) M, showing promising potential in SERS-based rapid detection of organic environmental pollutants.

Photoelectrochemical Water Splitting Properties of Ti-Ni-Si-O Nanostructures on Ti-Ni-Si Alloy

PubMed Central

Dong, Zhenbiao; Ning, Congqin

2017-01-01

Ti-Ni-Si-O nanostructures were successfully prepared on Ti-1Ni-5Si alloy foils via electrochemical anodization in ethylene glycol/glycerol solutions containing a small amount of water. The Ti-Ni-Si-O nanostructures were characterized by field-emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and diffuse reflectance absorption spectra. Furthermore, the photoelectrochemical water splitting properties of the Ti-Ni-Si-O nanostructure films were investigated. It was found that, after anodization, three different kinds of Ti-Ni-Si-O nanostructures formed in the α-Ti phase region, Ti2Ni phase region, and Ti5Si3 phase region of the alloy surface. Both the anatase and rutile phases of Ti-Ni-Si-O oxide appeared after annealing at 500 °C for 2 h. The photocurrent density obtained from the Ti-Ni-Si-O nanostructure photoanodes was 0.45 mA/cm2 at 0 V (vs. Ag/AgCl) in 1 M KOH solution. The above findings make it feasible to further explore excellent photoelectrochemical properties of the nanostructure-modified surface of Ti-Ni-Si ternary alloys. PMID:29088083

Photoelectrochemical Water Splitting Properties of Ti-Ni-Si-O Nanostructures on Ti-Ni-Si Alloy.

PubMed

Li, Ting; Ding, Dongyan; Dong, Zhenbiao; Ning, Congqin

2017-10-31

Ti-Ni-Si-O nanostructures were successfully prepared on Ti-1Ni-5Si alloy foils via electrochemical anodization in ethylene glycol/glycerol solutions containing a small amount of water. The Ti-Ni-Si-O nanostructures were characterized by field-emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and diffuse reflectance absorption spectra. Furthermore, the photoelectrochemical water splitting properties of the Ti-Ni-Si-O nanostructure films were investigated. It was found that, after anodization, three different kinds of Ti-Ni-Si-O nanostructures formed in the α-Ti phase region, Ti₂Ni phase region, and Ti₅Si₃ phase region of the alloy surface. Both the anatase and rutile phases of Ti-Ni-Si-O oxide appeared after annealing at 500 °C for 2 h. The photocurrent density obtained from the Ti-Ni-Si-O nanostructure photoanodes was 0.45 mA/cm² at 0 V (vs. Ag/AgCl) in 1 M KOH solution. The above findings make it feasible to further explore excellent photoelectrochemical properties of the nanostructure-modified surface of Ti-Ni-Si ternary alloys.

Effects of tai chi on cognition and instrumental activities of daily living in community dwelling older people with mild cognitive impairment.

PubMed

Siu, Mei-Yi; Lee, Diana T F

2018-02-02

Cognitive impairment places older adults at high risk of functional disability in their daily-life activities, and thus affecting their quality of life. This study aimed to examine the effects of Tai Chi on general cognitive functions and instrumental activities of daily living (IADL) in community-dwelling older people with mild cognitive impairment (MCI) in Hong Kong. The study adopted a multi-site nonequivalent control-group pretest-posttest design. 160 community-dwelling older people, aged ≥60, with MCI, from four community elderly centers participated in the study. The intervention group (IG, n = 80) received training in the Yang-style simple form of Tai Chi, at a frequency of two lessons per week for 16 weeks. Each lesson lasted for one hour. The control group (CG, n = 80) had no treatment regime and joined different recreational activity groups in community centers as usual within the study period. Outcome measures included measures of global cognitive status and IADL. The Chinese version of the Mini-Mental State Examination (CMMSE) was used for global cognitive assessment. The Hong Kong Chinese version of Lawton's Instrumental Activities of Daily Living (IADL-CV) was used to assess the participants' IADL levels. General Estimating Equations (GEE) was used to examine each of the outcome variables for the two groups at the two study time points (the baseline and at the end of the study). Meanwhile, minimum detectable change (MDC) was calculated to estimate the magnitude of changes required to eradicate the possibility of measurement error of outcome measures. Seventy four participants in the IG and 71 participants in the CG completed the study. With adjustments for differences in age, education, marital status and living conditions, the findings revealed that the participants in the IG scored significantly better on the CMMSE test (P = 0.001), and the instrumental ADL questionnaire (P = 0.004). However, those scores changes did not exceed the

Adios El Niño, Hello La Niña?

NASA Image and Video Library

2010-06-22

This image from NASA European Ocean Surface Topography Mission/Jason-2 shows that the moderate El Niño of the past year has officially bowed out, leaving his cool sibling, La Niña, poised to potentially take the equatorial stage.

Impact of Interstitial Ni on the Thermoelectric Properties of the Half-Heusler TiNiSn.

PubMed

Barczak, Sonia A; Buckman, Jim; Smith, Ronald I; Baker, Annabelle R; Don, Eric; Forbes, Ian; Bos, Jan-Willem G

2018-03-30

TiNiSn is an intensively studied half-Heusler alloy that shows great potential for waste heat recovery. Here, we report on the structures and thermoelectric properties of a series of metal-rich TiNi 1+y Sn compositions prepared via solid-state reactions and hot pressing. A general relation between the amount of interstitial Ni and lattice parameter is determined from neutron powder diffraction. High-resolution synchrotron X-ray powder diffraction reveals the occurrence of strain broadening upon hot pressing, which is attributed to the metastable arrangement of interstitial Ni. Hall measurements confirm that interstitial Ni causes weak n-type doping and a reduction in carrier mobility, which limits the power factor to 2.5-3 mW m -1 K -2 for these samples. The thermal conductivity was modelled within the Callaway approximation and is quantitively linked to the amount of interstitial Ni, resulting in a predicted value of 12.7 W m -1 K -1 at 323 K for stoichiometric TiNiSn. Interstitial Ni leads to a reduction of the thermal band gap and moves the peak ZT = 0.4 to lower temperatures, thus offering the possibility to engineer a broad ZT plateau. This work adds further insight into the impact of small amounts of interstitial Ni on the thermal and electrical transport of TiNiSn.

Impact of Interstitial Ni on the Thermoelectric Properties of the Half-Heusler TiNiSn

PubMed Central

Barczak, Sonia A.; Smith, Ronald I.; Baker, Annabelle R.; Don, Eric; Forbes, Ian

2018-01-01

TiNiSn is an intensively studied half-Heusler alloy that shows great potential for waste heat recovery. Here, we report on the structures and thermoelectric properties of a series of metal-rich TiNi1+ySn compositions prepared via solid-state reactions and hot pressing. A general relation between the amount of interstitial Ni and lattice parameter is determined from neutron powder diffraction. High-resolution synchrotron X-ray powder diffraction reveals the occurrence of strain broadening upon hot pressing, which is attributed to the metastable arrangement of interstitial Ni. Hall measurements confirm that interstitial Ni causes weak n-type doping and a reduction in carrier mobility, which limits the power factor to 2.5–3 mW m−1 K−2 for these samples. The thermal conductivity was modelled within the Callaway approximation and is quantitively linked to the amount of interstitial Ni, resulting in a predicted value of 12.7 W m−1 K−1 at 323 K for stoichiometric TiNiSn. Interstitial Ni leads to a reduction of the thermal band gap and moves the peak ZT = 0.4 to lower temperatures, thus offering the possibility to engineer a broad ZT plateau. This work adds further insight into the impact of small amounts of interstitial Ni on the thermal and electrical transport of TiNiSn. PMID:29601547

Crystallography of the NiHfSi Phase in a NiAl (0.5 Hf) Single-Crystal Alloy

NASA Technical Reports Server (NTRS)

Garg, A.; Noebe, R. D.; Darolia, R.

1996-01-01

Small additions of Hf to conventionally processed NiAl single crystals result in the precipitation of a high density of cuboidal G-phase along with a newly identified silicide phase. Both of these phases form in the presence of Si which is not an intentional alloying addition but is a contaminant resulting from contact with the ceramic shell molds during directional solidification of the single-crystal ingots. The morphology, crystal structure and Orientation Relationship (OR) of the silicide phase in a NiAl (0.5 at.%Hf) single-crystal alloy have been determined using transmission electron microscopy, electron microdiffraction and energy dispersive X-ray spectroscopy. Qualitative elemental analysis and indexing of the electron microdiffraction patterns from the new phase indicate that it is an orthorhombic NiHfSi phase with unit cell parameters, a = 0.639 nm, b = 0.389 nm and c = 0.72 nm, and space group Pnma. The NiHfSi phase forms as thin rectangular plates on NiAl/111/ planes with an OR that is given by NiHfSi(100))(parallel) NiAl(111) and NiHfSi zone axes(010) (parallel) NiAl zone axes (101). Twelve variants of the NiHfSi phase were observed in the alloy and the number of variants and rectangular morphology of NiHfSi plates are consistent with symmetry requirements. Quenching experiments indicate that nucleation of the NiHfSi phase in NiAI(Hf) alloys is aided by the formation of NiAl group of zone axes (111) vacancy loops that form on the NiAl /111/ planes.

Control of the transition between Ni-C and Ni-SI(a) states by the redox state of the proximal Fe-S cluster in the catalytic cycle of [NiFe] hydrogenase.

PubMed

Tai, Hulin; Nishikawa, Koji; Suzuki, Masayuki; Higuchi, Yoshiki; Hirota, Shun

2014-12-08

[NiFe] hydrogenase catalyzes the reversible cleavage of H2. The electrons produced by the H2 cleavage pass through three Fe-S clusters in [NiFe] hydrogenase to its redox partner. It has been reported that the Ni-SI(a), Ni-C, and Ni-R states of [NiFe] hydrogenase are involved in the catalytic cycle, although the mechanism and regulation of the transition between the Ni-C and Ni-SI(a) states remain unrevealed. In this study, the FT-IR spectra under light irradiation at 138-198 K show that the Ni-L state of [NiFe] hydrogenase is an intermediate between the transition of the Ni-C and Ni-SI(a) states. The transition of the Ni-C state to the Ni-SI(a) state occurred when the proximal [Fe4S4]p(2+/+) cluster was oxidized, but not when it was reduced. These results show that the catalytic cycle of [NiFe] hydrogenase is controlled by the redox state of its [Fe4S4]p(2+/+) cluster, which may function as a gate for the electron flow from the NiFe active site to the redox partner. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ni-P/Zn-Ni compositionally modulated multilayer coatings - Part 1: Electrodeposition and growth mechanism, composition, morphology, roughness and structure

NASA Astrophysics Data System (ADS)

Bahadormanesh, Behrouz; Ghorbani, Mohammad

2018-06-01

The Ni-P/Zn-Ni compositionally modulated multilayer coatings CMMCs were electrodeposited from a single bath by switching the cathodic current density. The composition, surface morphology, roughness, layers growth pattern as well as the phase structure of deposits were extensively studied via SEM, EDS, AFM and XRD analysis. Effects of bath ingredients on the electrodeposition behavior were analyzed through cathodic linear sweep voltammetry. Although the concentration of Zn2+ in bath was 13 times higher than Ni2+, the Zn-Ni deposition potential was much nearer to Ni deposition potential rather than that of Zn. Addition of NaH2PO2 to the Ni deposition bath considerably raised the current density and shifted the crystallization potential of Ni to more nobble values. Codeposition of P with Zn-Ni alloy lead to crack formation in the monolayer that was deposited in 60 mA/cm2. However, the cracks were not observed in the Zn-Ni layers of multilayers. Zn-Ni layers in CMMCs exhibited a three-dimensional pattern of growth while that of Ni-P layers was two-dimensional. Also, the Ni-P deposits tends to fill the discontinuities in Zn-Ni layers and performed leveling properties and lowered the surface roughness of Zn-Ni layers and CMMCs. Structural analysis demonstrated that Ni-P layers were amorphous and the Zn-Ni layers exhibited crystallite phase of Zn11Ni2. Thus, the Ni-P/Zn-Ni CMMCs comprised of alternate layers of amorphous Ni-P and nanocrystalline Zn Ni.

Effect of Ni content on the morphological evolution of Ni-YSZ solid oxide fuel cell electrodes

NASA Astrophysics Data System (ADS)

Chen-Wiegart, Yu-chen Karen; Kennouche, David; Scott Cronin, J.; Barnett, Scott A.; Wang, Jun

2016-02-01

The coarsening of Ni in Ni-yttria-stabilized zirconia (YSZ) anodes is a potential cause of long term solid oxide fuel cells (SOFC) performance degradation. The specifics of the Ni-YSZ structure—including Ni/YSZ ratio, porosity, and particle size distributions—are normally selected to minimize anode polarization resistance, but they also impact long-term stability. A better understanding of how these factors influence long-term stability is important for designing more durable anodes. The effect of structural details, e.g., Ni-YSZ ratio, on Ni coarsening has not been quantified. Furthermore, prior measurements have been done by comparing evolved structures with control samples, such that sample-to-sample variations introduce errors. Here, we report a four dimensional (three spatial dimensions and time) study of Ni coarsening in Ni-YSZ anode functional layers with different Ni/YSZ ratios, using synchrotron x-ray nano-tomography. The continuous structural evolution was observed and analyzed at sub-100 nm resolution. It is shown quantitatively that increasing the Ni/YSZ ratio increases the Ni coarsening rate. This is due to both increased pore volume and a decrease in the YSZ volume fraction, such that there is more free volume and a less obtrusive YSZ network, both of which allow greater Ni coarsening. The results are shown to be in good agreement with a power-law coarsening model. The finding is critical for informing the design of SOFC electrode microstructures that limit coarsening and performance degradation.

Effect of Ni Core Structure on the Electrocatalytic Activity of Pt-Ni/C in Methanol Oxidation

PubMed Central

Kang, Jian; Wang, Rongfang; Wang, Hui; Liao, Shijun; Key, Julian; Linkov, Vladimir; Ji, Shan

2013-01-01

Methanol oxidation catalysts comprising an outer Pt-shell with an inner Ni-core supported on carbon, (Pt-Ni/C), were prepared with either crystalline or amorphous Ni core structures. Structural comparisons of the two forms of catalyst were made using transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), and methanol oxidation activity compared using CV and chronoamperometry (CA). While both the amorphous Ni core and crystalline Ni core structures were covered by similar Pt shell thickness and structure, the Pt-Ni(amorphous)/C catalyst had higher methanol oxidation activity. The amorphous Ni core thus offers improved Pt usage efficiency in direct methanol fuel cells. PMID:28811402

Photosensitivity of the Ni-A state of [NiFe] hydrogenase from Desulfovibrio vulgaris Miyazaki F with visible light

DOE Office of Scientific and Technical Information (OSTI.GOV)

Osuka, Hisao; Graduate School of Materials Science, Nara Institute of Science and Technology, 8916-5, Takayama-cho, Ikoma-shi, Nara 630-0192; Shomura, Yasuhito

2013-01-04

Highlights: Black-Right-Pointing-Pointer Ni-A state of [NiFe] hydrogenase showed light sensitivity. Black-Right-Pointing-Pointer New FT-IR bands were observed with light irradiation of the Ni-A state. Black-Right-Pointing-Pointer EPR g-values of the Ni-A state shifted upon light irradiation. Black-Right-Pointing-Pointer The light-induced state converted back to the Ni-A state under the dark condition. -- Abstract: [NiFe] hydrogenase catalyzes reversible oxidation of molecular hydrogen. Its active site is constructed of a hetero dinuclear Ni-Fe complex, and the oxidation state of the Ni ion changes according to the redox state of the enzyme. We found that the Ni-A state (an inactive unready, oxidized state) of [NiFe] hydrogenasemore » from Desulfovibrio vulgaris Miyazaki F (DvMF) is light sensitive and forms a new state (Ni-AL) with irradiation of visible light. The Fourier transform infrared (FT-IR) bands at 1956, 2084 and 2094 cm{sup -1} of the Ni-A state shifted to 1971, 2086 and 2098 cm{sup -1} in the Ni-AL state. The g-values of g{sub x} = 2.30, g{sub y} = 2.23 and g{sub z} = 2.01 for the signals in the electron paramagnetic resonance (EPR) spectrum of the Ni-A state at room temperature varied for -0.009, +0.012 and +0.010, respectively, upon light irradiation. The light-induced Ni-AL state converted back immediately to the Ni-A state under dark condition at room temperature. These results show that the coordination structure of the Fe site of the Ni-A state of [NiFe] hydrogenase is perturbed significantly by light irradiation with relatively small coordination change at the Ni site.« less

Effect of NiO spin orientation on the magnetic anisotropy of the Fe film in epitaxially grown Fe/NiO/Ag(001) and Fe/NiO/MgO(001)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, W.; Jin, E.; Wu, J.

Single crystalline Fe/NiO bilayers were epitaxially grown on Ag(001) and on MgO(001), and investigated by Low Energy Electron Diffraction (LEED), Magneto-Optic Kerr Effect (MOKE), and X-ray Magnetic Linear Dichroism (XMLD). We find that while the Fe film has an in-plane magnetization in both Fe/NiO/Ag(001) and Fe/NiO/MgO(001) systems, the NiO spin orientation changes from in-plane direction in Fe/NiO/Ag(001) to out-of-plane direction in Fe/NiO/MgO(001). These two different NiO spin orientations generate remarkable different effects that the NiO induced magnetic anisotropy in the Fe film is much greater in Fe/NiO/Ag(001) than in Fe/NiO/MgO(001). XMLD measurement shows that the much greater magnetic anisotropy inmore » Fe/NiO/Ag(001) is due to a 90{sup o}-coupling between the in-plane NiO spins and the in-plane Fe spins.« less

Flexible bottom-emitting white organic light-emitting diodes with semitransparent Ni/Ag/Ni anode.

PubMed

Koo, Ja-Ryong; Lee, Seok Jae; Lee, Ho Won; Lee, Dong Hyung; Yang, Hyung Jin; Kim, Woo Young; Kim, Young Kwan

2013-05-06

We fabricated a flexible bottom-emitting white organic light-emitting diode (BEWOLED) with a structure of PET/Ni/Ag/Ni (3/6/3 nm)/ NPB (50 nm)/mCP (10 nm)/7% FIrpic:mCP (10 nm)/3% Ir(pq)(2) acac:TPBi (5 nm)/7% FIrpic:TPBi (5 nm)/TPBi (10 nm)/Liq (2 nm)/ Al (100 nm). To improve the performance of the BEWOLED, a multilayered metal stack anode of Ni/Ag/Ni treated with oxygen plasma for 60 sec was introduced into the OLED devices. The Ni/Ag/Ni anode effectively enhanced the probability of hole-electron recombination due to an efficient hole injection into and charge balance in an emitting layer. By comparing with a reference WOLED using ITO on glass, it is verified that the flexible BEWOLED showed a similar or better electroluminescence (EL) performance.

Investigation of diverse bacteria in cloud water at Mt. Tai, China.

PubMed

Xu, Caihong; Wei, Min; Chen, Jianmin; Sui, Xiao; Zhu, Chao; Li, Jiarong; Zheng, Lulu; Sui, Guodong; Li, Weijun; Wang, Wenxing; Zhang, Qingzhu; Mellouki, Abdelwahid

2017-02-15

Bacteria are abundant in atmospheric water phase with the potential to influence atmospheric processes and human health, yet relatively little information is known about the bacterial characteristics at high altitudes. Here we investigated the bacterial community by high throughput sequencing in 24 cloud water samples collected from September 26 to October 31, at the summit of Mt. Tai (36°15' N, 117°06' E, 1534m a.s.l) in China. Diverse bacterial population were identified and the gram-negative bacteria contributed the majority of total bacteria including Proteobacteria (81.6%) and Bacteroidetes (3.9%), followed by gram-positive bacteria Firmicutes (7.1%) and Actinobacteria (2.3%). These gram-negative taxa mainly inhabited in leaf-surface and cold environments. Meanwhile bacteria involved in the cloud condensation nuclei and ice nuclei formation were observed such as Sphingomonas (6.7%), Pseudomonas (4.1%), and Bacillus (1.1%). In addition, Sphingmonas was more active than that in daytime and participated in the cloud chemistry process. Meanwhile O 3 and SO 2 critically contributed to the variation of bacterial community. It is the first report on the bacterial community structure of cloud water over Asian area. Our results can serve as an important reference for environmental scientists, and biologists. Copyright © 2016. Published by Elsevier B.V.

Cooling field and ion-beam bombardment effects on exchange bias behavior in NiFe/(Ni,Fe)O bilayers.

PubMed

Lin, K W; Wei, M R; Guo, J Y

2009-03-01

The dependence of the cooling field and the ion-beam bombardment on the exchange bias effects in NiFe/(Ni,Fe)O bilayers were investigated. The positive exchange bias was found in the zero-field-cooled (ZFC) process whereas a negative exchange bias occurred in the FC process. The increased exchange field, H(ex) with increasing (Ni,Fe)O thicknesses indicates the thicker the AF (Ni,Fe)O, the stronger the exchange coupling between the NiFe layer and the (Ni,Fe)O layer. In addition, the dependence of the H(ex) (ZFC vs. FC) on the (Ni,Fe)O thicknesses reflects the competition between the applied magnetic field and the (Ni,Fe)O surface layer exchange coupled to the NiFe layer. Further, an unusual oscillating exchange bias was observed in NiFe/(Ni,Fe)O bilayers that results from the surface of the (Ni,Fe)O layer being bombarded with different Ar-ion energies using End-Hall deposition voltages (V(EH)) from 0 to 150 V. The behavior of the H(ex) and the H(c) with the V(EH) is attributed to the surface spin reorientation that is due to moderate ion-beam bombardment effects on the surface of the (Ni,Fe)O layer. Whether the (Ni,Fe)O antiferromagnetic spins are coupled to the NiFe moments antiferromagnetically or ferromagnetically changes the sign of the exchange bias.

Corrosive sliding wear behavior of laser clad Mo 2Ni 3Si/NiSi intermetallic coating

NASA Astrophysics Data System (ADS)

Lu, X. D.; Wang, H. M.

2005-05-01

Many ternary metal silicides such as W 2Ni 3Si, Ti 2Ni 3Si and Mo 2Ni 3Si with the topologically closed-packed (TCP) hP12 MgZn 2 type Laves phase crystal structure are expected to have outstanding wear and corrosion resistance due to their inherent high hardness and sluggish temperature dependence and strong atomic bonds. In this paper, Mo 2Ni 3Si/NiSi intermetallic coating was fabricated on substrate of an austenitic stainless steel AISI321 by laser cladding using Ni-Mo-Si elemental alloy powders. Microstructure of the coating was characterized by optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDS). Wear resistance of the coating is evaluated under corrosive sliding wear test condition. Influence of corrosion solutions on the wear resistance of the coating was studied and the wear mechanism was discussed based on observations of worn surface morphology. Results showed that the laser clad Mo 2Ni 3Si/NiSi composite coating have a fine microstructure of Mo 2Ni 3Si primary dendrites and the interdendritic Mo 2Ni 3Si/NiSi eutectics. The coating has excellent corrosive wear resistance compared with austenitic stainless steel AISI321 under acid, alkaline and saline corrosive environments.

Nickel distribution and isotopic fractionation in a Brazilian lateritic regolith: Coupling Ni isotopes and Ni K-edge XANES

NASA Astrophysics Data System (ADS)

Ratié, G.; Garnier, J.; Calmels, D.; Vantelon, D.; Guimarães, E.; Monvoisin, G.; Nouet, J.; Ponzevera, E.; Quantin, C.

2018-06-01

Ultramafic (UM) rocks are known to be nickel (Ni) rich and to weather quickly, which makes them a good candidate to look at the Ni isotope systematics during weathering processes at the Earth's surface. The present study aims at identifying the Ni solid speciation and discussing the weathering processes that produce Ni isotope fractionation in two deep laterite profiles under tropical conditions (Barro Alto, Goiás State, Brazil). While phyllosilicates and to a lower extent goethite are the main Ni-bearing phases in the saprolitic part of the profile, iron (Fe) oxides dominate the Ni budget in the lateritic unit. Nickel isotopic composition (δ60Ni values) has been measured in each unit of the regolith, i.e., rock, saprock, saprolite and laterite (n = 52). δ60Ni varies widely within the two laterite profiles, from -0.10 ± 0.05‰ to 1.43 ± 0.05‰, showing that significant Ni isotope fractionation occurs during the weathering of UM rocks. Overall, our results show that during weathering, the solid phase is depleted in heavy Ni isotopes due to the preferential sorption and incorporation of light Ni isotopes into Fe oxides; the same mechanisms likely apply to the incorporation of Ni into phyllosilicates (type 2:1). However, an isotopically heavy Ni pool is observed in the solid phase at the bottom of the saprolitic unit. This feature can be explained by two hypotheses that are not mutually exclusive: (i) a depletion in light Ni isotopes during the first stage of weathering due to the preferential dissolution of light Ni-containing minerals, and (ii) the sorption or incorporation of isotopically heavy Ni carried by percolating waters (groundwater samples have δ60Ni of 2.20 and 2.27‰), that were enriched in heavy Ni isotopes due to successive weathering processes in the overlying soil and laterite units.

Role of Ni-tolerant Bacillus spp. and Althea rosea L. in the phytoremediation of Ni-contaminated soils.

PubMed

Khan, Waheed Ullah; Yasin, Nasim Ahmad; Ahmad, Sajid Rashid; Ali, Aamir; Ahmed, Shakil; Ahmad, Aqeel

2017-05-04

In our current study, four nickel-tolerant (Ni-tolerant) bacterial species viz, Bacillus thuringiensis 002, Bacillus fortis 162, Bacillus subtilis 174, and Bacillus farraginis 354, were screened using Ni-contaminated media. The screened microbes exhibited positive results for synthesis of indole acetic acid (IAA), siderophore production, and phosphate solubilization. The effects of these screened microbes on Ni mobility in the soil, root elongation, plant biomass, and Ni uptake in Althea rosea plants grown in Ni-contaminated soil (200 mg Ni kg -1 ) were evaluated. Significantly higher value for water-extractable Ni (38 mg kg -1 ) was observed in case of Ni-amended soils inoculated with B. subtilis 174. Similarly, B. thuringiensis 002, B. fortis 162, and B. subtilis 174 significantly enhanced growth and Ni uptake in A. rosea. The Ni uptake in the shoots and roots of B. subtilis 174-inoculated plants enhanced up to 1.7 and 1.6-fold, respectively, as compared to that in the un-inoculated control. Bacterial inoculation also significantly improved the root and shoot biomass of treated plants. The current study presents a novel approach for bacteria-assisted phytoremediation of Ni-contaminated areas.

Sputtering Yields of Si and Ni from the Ni1-xSix System Studied by Rutherford Backscattering Spectrometry

NASA Astrophysics Data System (ADS)

Kim, Su Chol; Yamaguchi, Satoru; Kataoka, Yoshihide; Iwami, Motohiro; Hiraki, Akio; Satou, Mamoru; Fujimoto, Fuminori

1982-01-01

Sputtering yields of Si and Ni from thin layer films of Ni-Si compounds (Ni1-xSix), including the pure materials (Ni and Si), caused by 5 keV Ar+ ion bombardment were investigated using backscattering spectrometry. The sputtering yield for Si from Ni1-xSix increased with increasing Si concentration. However, there is an abrupt decrease in the yield for Si concentrations above NiSi2 to pure Si. This is in clear contrast to the sputtering yield of Ni from Ni1-xSix which increased with increasing Ni concentration monotonously. These results are discussed on the basis of both the difference in the atomic density and the electronic state of the alloy.

Influence of Ni on Martensitic Phase Transformations in NiTi Shape Memory Alloys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frenzel, J.; George, Easo P; Dlouhy, A.

High-precision data on phase transformation temperatures in NiTi, including numerical expressions for the effect of Ni on M{sub S}, M{sub F}, A{sub S}, A{sub F} and T{sub 0}, are obtained, and the reasons for the large experimental scatter observed in previous studies are discussed. Clear experimental evidence is provided confirming the predictions of Tang et al. 1999 regarding deviations from a linear relation between the thermodynamic equilibrium temperature and Ni concentration. In addition to affecting the phase transition temperatures, increasing Ni contents are found to decrease the width of thermal hysteresis and the heat of transformation. These findings are rationalizedmore » on the basis of the crystallographic data of Prokoshkin et al. 2004 and the theory of Ball and James. The results show that it is important to document carefully the details of the arc-melting procedure used to make shape memory alloys and that, if the effects of processing are properly accounted for, precise values for the Ni concentration of the NiTi matrix can be obtained.« less

Microstructure and wear properties of laser clad Ti2Ni3Si/Ni3Ti multiphase intermetallic coatings

NASA Astrophysics Data System (ADS)

Wang, H. M.; Tang, H. B.; Cai, L. X.; Cao, F.; Zhang, L. Y.; Yu, R. L.

2005-05-01

Wear resistant Ti2Ni3Si/Ni3Ti multiphase intermetallic coatings with a microstructure consisting of Ti2Ni3Si primary dendrites and interdendritic Ti2Ni3Si/Ni3Ti eutectic were fabricated on a substrate of 0.2% C plain carbon steel by a laser cladding process with Ti-Ni-Si alloy powders. The Ti2Ni3Si/Ni3Ti coatings have excellent wear resistance and a low coefficient of friction under metallic dry sliding wear test conditions with hardened 0.45% C carbon steel as the silide-mating counterpart. The excellent tribological properties of the coating are attributed to the high hardness, strong covalent-dominant atomic bonds of the ternary metal silicide Ti2Ni3Si and to the high yield strength and strong yield anomaly of the intermetallic compound Ni3Ti.

Ti(Ni,Cu) pseudobinary compounds as efficient negative electrodes for Ni-MH batteries

NASA Astrophysics Data System (ADS)

Emami, Hoda; Cuevas, Fermin; Latroche, Michel

2014-11-01

The effect of Ni by Cu substitution on the structural, solid-gas and electrochemical hydrogenation properties of TiNi has been investigated. Pseudo-binary TiNi1-xCux (x ≤ 0.5) compounds have been synthesized by induction melting. They crystallize in B2 structure above 350 K and either in B19‧ (x < 0.1) or B19 (0.2 ≤ x ≤ 0.5) at room temperature (RT). For all compounds, Pressure-Composition Isotherms at 423 K exhibit a single slopping plateau pressure within the range 10-3-1 MPa of hydrogen pressure revealing a metal to hydride transformation. Both the hydrogenation capacity and the hydride stability decrease with Cu-content. The hydrided pseudobinary compounds crystallize in the tetragonal S.G. I4/mmm structure as for TiNi hydride. The electrochemical discharge capacity increases with Cu content from 150 mAh g-1 for TiNi up to 300 mAh g-1 for TiNi0.8Cu0.2 and then decreases again for larger Cu amounts. Electrochemical isotherms and in-situ neutron diffraction measurements at RT demonstrate that such a capacity increase results from a metal to hydride phase transformation in which the hydride phase is destabilized by Cu substitution. The TiNi0.8Cu0.2 compound exhibits interesting cycling stability for 30 cycles and good high-rate capability at D/2 rate. This compound has promising electrochemical properties as compared to commercial LaNi5-type alloys with the advantage of being rare-earth metal free.

Phase Equilibria of the Sn-Ni-Si Ternary System and Interfacial Reactions in Sn-(Cu)/Ni-Si Couples

NASA Astrophysics Data System (ADS)

Fang, Gu; Chen, Chih-chi

2015-07-01

Interfacial reactions in Sn/Ni-4.5 wt.%Si and Sn-Cu/Ni-4.5 wt.%Si couples at 250°C, and Sn-Ni-Si ternary phase equilibria at 250°C were investigated in this study. Ni-Si alloys, which are nonmagnetic, can be regarded as a diffusion barrier layer material in flip chip packaging. Solder/Ni-4.5 wt.%Si interfacial reactions are crucial to the reliability of soldered joints. Phase equilibria information is essential for development of solder/Ni-Si materials. No ternary compound is present in the Sn-Ni-Si ternary system at 250°C. Extended solubility of Si in the phases Ni3Sn2 and Ni3Sn is 3.8 and 6.1 at.%, respectively. As more Si dissolves in these phases their lattice constants decrease. No noticeable ternary solubility is observed for the other intermetallics. Interfacial reactions in solder/Ni-4.5 wt.%Si are similar to those for solder/Ni. Si does not alter the reaction phases. No Si solubility in the reaction phases was detected, although rates of growth of the reaction phases were reduced. Because the alloy Ni-4.5 wt.%Si reacts more slowly with solders than pure Ni, the Ni-4.5 wt.%Si alloy could be a potential new diffusion barrier layer material for flip chip packaging.

Atomic-scale dynamics of edge dislocations in Ni and concentrated solid solution NiFe alloys

DOE PAGES

Zhao, Shijun; Osetsky, Yuri N.; Zhang, Yanwen; ...

2017-01-19

Single-phase concentrated solid solution alloys (CSAs), including high entropy alloys, exhibit excellent mechanical properties compared to conventional dilute alloys. However, the origin of this observation is not clear yet because the dislocation properties in CSAs are poorly understood. In this work, the mobility of a <110>{111} edge dislocation in pure Ni and equiatomic solid solution Ni 0.5Fe 0.5 (NiFe) is studied using molecular dynamics simulations with different empirical potentials. The threshold stress to initiate dislocation movement in NiFe is found to be much higher compared to pure Ni. The drag coefficient of the dislocation motion calculated from the linear regimemore » of dislocation velocities versus applied stress suggests that the movement of dislocations in NiFe is strongly damped compared to that in Ni. The present results indicate that the mobility of edge dislocations in fcc CSAs are controlled by the fluctuations in local stacking fault energy caused by the local variation of alloy composition.« less

Effect of Ni content on the morphological evolution of Ni-YSZ solid oxide fuel cell electrodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen-Wiegart, Yu-chen Karen; Kennouche, David; Scott Cronin, J.

2016-02-22

The coarsening of Ni in Ni–yttria-stabilized zirconia (YSZ) anodes is a potential cause of long term solid oxide fuel cells (SOFC) performance degradation. The specifics of the Ni-YSZ structure—including Ni/YSZ ratio, porosity, and particle size distributions—are normally selected to minimize anode polarization resistance, but they also impact long-term stability. A better understanding of how these factors influence long-term stability is important for designing more durable anodes. The effect of structural details, e.g., Ni-YSZ ratio, on Ni coarsening has not been quantified. Furthermore, prior measurements have been done by comparing evolved structures with control samples, such that sample-to-sample variations introduce errors.more » Here, we report a four dimensional (three spatial dimensions and time) study of Ni coarsening in Ni-YSZ anode functional layers with different Ni/YSZ ratios, using synchrotron x-ray nano-tomography. The continuous structural evolution was observed and analyzed at sub-100 nm resolution. It is shown quantitatively that increasing the Ni/YSZ ratio increases the Ni coarsening rate. This is due to both increased pore volume and a decrease in the YSZ volume fraction, such that there is more free volume and a less obtrusive YSZ network, both of which allow greater Ni coarsening. The results are shown to be in good agreement with a power-law coarsening model. The finding is critical for informing the design of SOFC electrode microstructures that limit coarsening and performance degradation.« less

Hybrid Energy Storage of Ni(OH)2-coated N-doped Graphene Aerogel//N-doped Graphene Aerogel for the Replacement of NiCd and NiMH Batteries.

PubMed

Sirisinudomkit, Pichamon; Iamprasertkun, Pawin; Krittayavathananon, Atiweena; Pettong, Tanut; Dittanet, Peerapan; Sawangphruk, Montree

2017-04-25

Although Nickel-Cadmium (NiCd) and Nickel-metal hydride (NiMH) batteries have been widely used, their drawbacks including toxic Cd and expensive La alloy at the negative electrodes, low energy density (40-60 Wh/kg for NiCd and 140-300 Wh/L for NiMH), low power density (150 W/kg for NiCd and 1000 W/kg for NiMH), and low working potential (1.2 V) limit their applications. In this work, Cd and La alloy were replaced with N-doped reduced graphene oxide aerogel (N-rGO ae ) providing a hybrid energy storage (HES) having the battery and supercapacitor effects. The HES of Ni(OH) 2 -coated N-rGO ae //N-rGO ae provides 1.5 V, a specific energy of 146 Wh/kg, a maximum specific power of 7705 W/kg, and high capacity retention over 84.6% after 5000 cycles. The mass change at the positive electrode during charging/discharging is 8.5 µg cm -2 owing to the insertion/desertion of solvated OH - into the α-Ni(OH) 2 -coated N-rGO ae . At the negative electrode, the mass change of the solvated K + , physically adsorbed/desorbed to the N-rGO ae , is 7.5 μg cm -2 . In situ X-ray absorption spectroscopy (XAS) shows highly reversible redox reaction of α-Ni(OH) 2 . The as-fabricated device without using toxic Cd and expensive La alloy has a potential as a candidate of NiCd and NiMH.

Phonon Dispersion in Amorphous Ni-Alloys

NASA Astrophysics Data System (ADS)

Vora, A. M.

2007-06-01

The well-known model potential is used to investigate the longitudinal and transverse phonon dispersion curves for six Ni-based binary amorphous alloys, viz. Ni31Dy69, Ni33Y67, Ni36Zr64, Ni50Zr50, Ni60 Nb40, and Ni81B19. The thermodynamic and elastic properties are also computed from the elastic limits of the phonon dispersion curves. The theoretical approach given by Hubbard-Beeby is used in the present study to compute the phonon dispersion curves. Five local field correction functions proposed by Hartree, Taylor, Ichimaru-Utsumi, Farid et al. and Sarkar et al. are employed to see the effect of exchange and correlation in the aforesaid properties.

Long Term Performance Retention Test Using High Power COTS NiCd and NiMH Cells

NASA Technical Reports Server (NTRS)

Hall, Dan; Darcy, Eric; Strangways, Brad; Nelson, Tim

2003-01-01

This slide presentation reviews the tests and results for performance retention of high powered commercial off the shelf (COTS) NiCd, and NiMH cells. Electromechanical actuators for space flight requires short duration high power batteries. The concern is that NiCd battery designs demonstrate an unfavorable power degradation after long periods of inactivity. Cycling can recover some of the decay, but this reduces the readiness that these batteries must have. Two 5-cell SubC stick test batteries ere chosen using NiCd and NiMH were tested and then the differences for charge maintenance were compared.

Effects of wheelchair Tai Chi on physical and mental health among elderly with disability.

PubMed

Wang, Yong Tai; Li, Zhanghua; Yang, Yi; Zhong, Yaping; Lee, Shih-Yu; Chen, Shihui; Chen, Yu-Ping

2016-01-01

A 12-week Wheelchair Tai Chi 10 Form (WTC10) intervention was conducted among elderly with disability to examine the effect of this WTC10 intervention on selected physical and mental health variables. Thirteen (age 87.23 ± 6.71) in the WTC10 intervention group and 15 (age 89.73 ± 6.31) in the control group completed the study. Independent t-tests and paired t-tests were employed to examine the differences between groups and within groups, respectively, at pretest and post-test. The WTC10 intervention group showed significant improvements in systolic and diastolic blood pressure, shoulder external rotation, left trunk rotation and total trunk rotation after the intervention. A 12-week WTC10 intervention had positive effects on blood pressure, range of motion at the shoulder and trunk, physical activity, and mental health among the elderly with disability. WTC10 is a feasible and safe exercise for the elderly with disability.

Phase transformation and deformation behavior of NiTi-Nb eutectic joined NiTi wires

PubMed Central

Wang, Liqiang; Wang, Cong; Zhang, Lai-Chang; Chen, Liangyu; Lu, Weijie; Zhang, Di

2016-01-01

NiTi wires were brazed together via eutectic reaction between NiTi and Nb powder deposited at the wire contact region. Phase transformation and deformation behavior of the NiTi-Nb eutectic microstructure were investigated using transmission electron microscopy (TEM) and cyclic loading-unloading tests. Results show that R phase and B19′ martensite transformation are induced by plastic deformation. R phase transformation, which significantly contributes to superelasticity, preferentially occurs at the interfaces between NiTi and eutectic region. Round-shaped Nb-rich phase with rod-like and lamellar-type eutectics are observed in eutectic regions. These phases appear to affect the deformation behavior of the brazed NiTi-Nb region via five distinct stages in stress-strain curves: (I) R phase reorientation, (II) R phase transformation from parent phase, (III) elastic deformation of reoriented martensite accompanied by the plastic deformation of Nb-rich phase and lamellar NiTi-Nb eutectic, (IV) B19′ martensitic transformation, and (V) plastic deformation of the specimen. PMID:27049025

Low-temperature CO oxidation on Ni(111) and on a Au/Ni(111) surface alloy.

PubMed

Knudsen, Jan; Merte, Lindsay R; Peng, Guowen; Vang, Ronnie T; Resta, Andrea; Laegsgaard, Erik; Andersen, Jesper N; Mavrikakis, Manos; Besenbacher, Flemming

2010-08-24

From an interplay between scanning tunneling microscopy, temperature programmed desorption, X-ray photoelectron spectroscopy, and density functional theory calculations we have studied low-temperature CO oxidation on Au/Ni(111) surface alloys and on Ni(111). We show that an oxide is formed on both the Ni(111) and the Au/Ni(111) surfaces when oxygen is dosed at 100 K, and that CO can be oxidized at 100 K on both of these surfaces in the presence of weakly bound oxygen. We suggest that low-temperature CO oxidation can be rationalized by CO oxidation on O(2)-saturated NiO(111) surfaces, and show that the main effect of Au in the Au/Ni(111) surface alloy is to block the formation of carbonate and thereby increase the low-temperature CO(2) production.

NiO-Microflower Formed by Nanowire-weaving Nanosheets with Interconnected Ni-network Decoration as Supercapacitor Electrode

PubMed Central

Ci, Suqing; Wen, Zhenhai; Qian, Yuanyuan; Mao, Shun; Cui, Shumao; Chen, Junhong

2015-01-01

We propose a ‘weaving’ evolution mechanism, by systematically investigating the products obtained in controlled experiments, to demonstrate the formation of Ni-based ‘microflowers’ which consists of multiple characteristic dimensions, in which the three dimensional (3D) NiO ‘microflower’ is constructed by a two-dimensional (2D) nanosheet framework that is derived from weaving one-dimensional (1D) nanowires. We found such unique nanostructures are conducive for the generation of an electrically conductive Ni-network on the nanosheet surface after being exposed to a reducing atmosphere. Our study offers a promising strategy to address the intrinsic issue of poor electrical conductivity for NiO-based materials with significant enhancement of utilization of NiO active materials, leading to a remarkable improvement in the performance of the Ni-NiO microflower based supercapacitor. The optimized Ni-NiO microflower material showed a mass specific capacitance of 1,828 F g−1, and an energy density of 15.9 Wh kg−1 at a current density of 0.5 A g−1. This research not only contributes to understanding the formation mechanism of such ‘microflower’ structures but also offers a promising route to advance NiO based supercapacitor given their ease of synthesis, low cost, and long-term stability. PMID:26165386

Access to Formally Ni(I) States in a Heterobimetallic NiZn System

PubMed Central

Uyeda, Christopher

2014-01-01

Heterobimetallic NiZn complexes featuring metal centers in distinct coordination environments have been synthesized using diimine-dioxime ligands as binucleating scaffolds. A tetramethylfuran-containing ligand derivative enables a stable one-electron-reduced S = 1/2 species to be accessed using Cp2Co as a chemical reductant. The resulting pseudo-square planar complex exhibits spectroscopic and crystallographic characteristics of a ligand-centered radical bound to a Ni(II) center. Upon coordination of a π-acidic ligand such as PPh3, however, a five-coordinate Ni(I) metalloradical is formed. The electronic structures of these reduced species provide insight into the subtle effects of ligand structure on the potential and reversibility of the NiII/I couple for complexes of redox-active tetraazamacrocycles. PMID:25614786

Effect of Ni content on the morphological evolution of Ni-YSZ solid oxide fuel cell electrodes

DOE PAGES

Chen-Wiegart, Yu-chen Karen; Kennouche, David; Scott Cronin, J.; ...

2016-02-25

The coarsening of Ni in Ni–yttria-stabilized zirconia (YSZ) anodes is a potential cause of long term solid oxide fuel cells (SOFC) performance degradation. The specifics of the Ni-YSZ structure—including Ni/YSZ ratio, porosity, and particle size distributions—are normally selected to minimize anode polarization resistance, but they also impact long-term stability. A better understanding of how these factors influence long-term stability is important for designing more durable anodes. The effect of structural details, e.g., Ni-YSZ ratio, on Ni coarsening has not been quantified. Furthermore, prior measurements have been done by comparing evolved structures with control samples, such that sample-to-sample variations introduce errors.more » Here in this paper, we report a four dimensional (three spatial dimensions and time) study of Ni coarsening in Ni-YSZ anode functional layers with different Ni/YSZ ratios, using synchrotron x-ray nano-tomography. The continuous structural evolution was observed and analyzed at sub-100 nm resolution. It is shown quantitatively that increasing the Ni/YSZ ratio increases the Ni coarsening rate. This is due to both increased pore volume and a decrease in the YSZ volume fraction, such that there is more free volume and a less obtrusive YSZ network, both of which allow greater Ni coarsening. The results are shown to be in good agreement with a power-law coarsening model. In conclusion, the finding is critical for informing the design of SOFC electrode microstructures that limit coarsening and performance degradation.« less

Effect of Ni content on the morphological evolution of Ni-YSZ solid oxide fuel cell electrodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen-Wiegart, Yu-chen Karen; Kennouche, David; Scott Cronin, J.

The coarsening of Ni in Ni–yttria-stabilized zirconia (YSZ) anodes is a potential cause of long term solid oxide fuel cells (SOFC) performance degradation. The specifics of the Ni-YSZ structure—including Ni/YSZ ratio, porosity, and particle size distributions—are normally selected to minimize anode polarization resistance, but they also impact long-term stability. A better understanding of how these factors influence long-term stability is important for designing more durable anodes. The effect of structural details, e.g., Ni-YSZ ratio, on Ni coarsening has not been quantified. Furthermore, prior measurements have been done by comparing evolved structures with control samples, such that sample-to-sample variations introduce errors.more » Here in this paper, we report a four dimensional (three spatial dimensions and time) study of Ni coarsening in Ni-YSZ anode functional layers with different Ni/YSZ ratios, using synchrotron x-ray nano-tomography. The continuous structural evolution was observed and analyzed at sub-100 nm resolution. It is shown quantitatively that increasing the Ni/YSZ ratio increases the Ni coarsening rate. This is due to both increased pore volume and a decrease in the YSZ volume fraction, such that there is more free volume and a less obtrusive YSZ network, both of which allow greater Ni coarsening. The results are shown to be in good agreement with a power-law coarsening model. In conclusion, the finding is critical for informing the design of SOFC electrode microstructures that limit coarsening and performance degradation.« less

Temporal and diurnal variations of carbonaceous aerosols and major ions in biomass burning influenced aerosols over Mt. Tai in the North China Plain during MTX2006

NASA Astrophysics Data System (ADS)

Boreddy, Suresh K. R.; Kawamura, Kimitaka; Okuzawa, Kazuhiro; Kanaya, Yugo; Wang, Zifa

2017-04-01

To better understand the impact of agricultural waste burning on the air quality of free troposphere over the North China Plain (NCP), we collected total suspended particles (TSP) at the summit of Mt. Tai, located in the NCP using a high volume air sampler during 29 May to 28 June 2006, when the field burning of agricultural residue was intense. Temporal variations of all measured species showed that their concentration increases from late May to mid June (major BB period), peaking during 12-14 June, and then significantly decreased towards late June (minor BB period). We noticed that a significant reduction in the concentrations of carbonaceous aerosols during the period of 8-11 June, when the wind direction shifted from southerly to northerly. We found that concentrations of carbonaceous aerosols and some major ions showed several times higher during major BB period than those of minor BB period. We also found that nighttime concentrations are higher than daytime during major BB period, suggesting that a long-range atmospheric transport of biomass burning plumes in the free troposphere, which arrived at the summit of Mt. Tai. In contrast, daytime concentrations are higher than nighttime during minor BB period. We found higher concentrations of secondary organic carbon (SOC) during major BB period, suggesting that formation of secondary organic aerosols through aqueous phase chemistry under high NOx conditions during a long-range atmospheric transport. nss-K+ showed about four times higher concentrations during major BB than those of minor BB. Concentrations of nss-Ca2+ are higher in nighttime during major BB period, implying that a significant long-range atmospheric transport of mineral dust over the sampling site. These results are further supported by the positive matrix factorization (PMF) analysis, which showed that biomass burning was a major source for the carbonaceous aerosols followed by mineral dust sources over the summit of Mt. Tai.

Effect of solute atoms on swelling in Ni alloys and pure Ni under He + ion irradiation

NASA Astrophysics Data System (ADS)

Wakai, E.; Ezawa, T.; Imamura, J.; Takenaka, T.; Tanabe, T.; Oshima, R.

2002-12-01

The effects of solute atoms on microstructural evolutions have been investigated using Ni alloys under 25 keV He + irradiation at 500 °C. The specimens used were pure Ni, Ni-Si, Ni-Co, Ni-Cu, Ni-Mn and Ni-Pd alloys with different volume size factors. The high number densities of dislocation loops about 1.5×10 22 m -3 were formed in the specimens irradiated to 1×10 19 ions/m 2, and they were approximately equivalent, except for Ni-Si. The mean size of loops tended to increase with the volume size factor of solute atoms. In a dose of 4×10 20 ions/m 2, the swelling was changed from 0.2% to 4.5%, depending on the volume size factors. The number densities of bubbles tended to increase with the absolute values of the volume size factor, and the swelling increased with the volume size factors. This suggests that the mobility of helium and vacancy atoms may be influenced by the interaction of solute atoms with them.

NiCoO2 flowers grown on the aligned-flakes coated Ni foam for application in hybrid energy storage

NASA Astrophysics Data System (ADS)

Xu, Xiaoyang; Zhao, Huilin; Zhou, JingKuo; Xue, Ruinan; Gao, Jianping

2016-10-01

Many NiCoO2 flowers with an average diameter of about 4 μm were grown on the NiCoO2 flakes coated Ni foam (denoted as NiCoO2/Ni foam) through a simple hydrothermal method and confirmed by scanning and transmission electron microscopies, X-ray diffraction and X-ray photoelectron spectrum measurements. The NiCoO2/Ni foam with high specific area and porosity was directly used as the working electrode without any binders. The measured specific capacitance of NiCoO2 grown on Ni foam is 756 F/g at 0.75 A/g using a three-electrode setup in 1 M KOH. Considering the high capacity of NiCoO2 and the good stability of rGO, the NiCoO2/Ni foam//rGO hybrid supercapacitor combining NiCoO2/Ni foam and rGO shows very good properties, such as high specific capacitance (82 F/g at 2 A/g based on the total mass of active materials), high energy density (25.7 Wh/kg at 1500 W/kg based on the total mass of active materials), good stability (about 90% capacitance retention after 2000-cycle at 100 mV/s), and low charge ion transfer resistance.

Blending Cr 2O 3 into a NiO-Ni electrocatalyst for sustained water splitting

DOE PAGES

Gong, Ming; Zhou, Wu; Kenney, Michael James; ...

2015-08-24

The rising H 2 economy demands active and durable electrocatalysts based on low-cost, earth-abundant materials for water electrolysis/photolysis. Here we report nanoscale Ni metal cores over-coated by a Cr 2O 3-blended NiO layer synthesized on metallic foam substrates. The Ni@NiO/Cr 2O 3 triphase material exhibits superior activity and stability similar to Pt for the hydrogen-evolution reaction in basic solutions. The chemically stable Cr 2O 3 is crucial for preventing oxidation of the Ni core, maintaining abundant NiO/Ni interfaces as catalytically active sites in the heterostructure and thus imparting high stability to the hydrogen-evolution catalyst. The highly active and stable electrocatalystmore » enables an alkaline electrolyzer operating at 20 mA cm –2 at a voltage lower than 1.5 V, lasting longer than 3 weeks without decay. Thus, the non-precious metal catalysts afford a high efficiency of about 15 % for light-driven water splitting using GaAs solar cells.« less

Characterization and electrochemical properties of Ni(Si)/Ni5Si2 multiphase coatings prepared by HVOF spraying

NASA Astrophysics Data System (ADS)

Verdian, M. M.; Raeissi, K.; Salehi, M.

2012-11-01

Ni(Si)/Ni5Si2 powders were produced by mechanical alloying (MA) of Ni-25 at.% Si powder mixture. Then, the as-milled powders were sprayed onto copper substrate using high velocity oxy-fuel (HVOF) process. The phase composition and microstructure of the coatings were examined by X-ray diffractometry and scanning electron microscopy. Polarization tests and electrochemical impedance spectroscopy (EIS) measurements were also employed to study corrosion performance of the coatings in 3.5% NaCl solution. The results showed that although single phase Ni3Si was formed during annealing of Ni(Si)/Ni5Si2 powders, but, only Ni(Si) and Ni5Si2 are present in HVOF coatings and no new phase has been formed during spraying. The coatings had microhardness up to 746 HV0.05. Further investigations showed the corrosion performance of multiphase coatings in 3.5% NaCl solution was better than that of copper substrate. The phase transitions during MA, HVOF and annealing processes were discussed in association with Ni-Si phase diagram and nature of each process.

One-step facile synthesis of Ni2P/C as cathode material for Ni/Zn aqueous secondary battery

NASA Astrophysics Data System (ADS)

Li, JiLan; Chen, ChangGuo

2018-01-01

Nickel phosphides/carbon(Ni2P/C) composites have been successfully synthesized via a simple one-pot hydrothermal method using glucose as carbon source for the first time. By contrast, the pure Ni2P was prepared under the same conditions without glucose. The results show that glucose not only provide the carbon source, but also prevent the aggregation of Ni2P particles. The as-obtained Ni2P/C composites and pure Ni2P were used as cathode material for alkaline Ni/Zn battery. Owing to unique Ni2P/C composites and loose, Ultra thin flower-like shape the synthesized Ni2P/C material delivers high capacity of 176 mAh g-1 at 1 A g-1 and 82 mAh g-1 at 5 A g-1 current density in Ni2P/C-Zn battery. Moreover, it shows a good cycling life that capacity fading only about 6.2% after 1500 cycles. All of these indicate that the prepared Ni2P/C composites may be a new promising cathode material for Ni-Zn rechargeable battery.

Solution growth of NiO nanosheets supported on Ni foam as high-performance electrodes for supercapacitors

NASA Astrophysics Data System (ADS)

Yan, Hailong; Zhang, Deyang; Xu, Jinyou; Lu, Yang; Liu, Yunxin; Qiu, Kangwen; Zhang, Yihe; Luo, Yongsong

2014-08-01

Well-aligned nickel oxide (NiO) nanosheets with the thickness of a few nanometers supported on a flexible substrate (Ni foam) have been fabricated by a hydrothermal approach together with a post-annealing treatment. The three-dimensional NiO nanosheets were further used as electrode materials to fabricate supercapacitors, with high specific capacitance of 943.5, 791.2, 613.5, 480, and 457.5 F g-1 at current densities of 5, 10, 15, 20, and 25 A g-1, respectively. The NiO nanosheets combined well with the substrate. When the electrode material was bended, it can still retain 91.1% of the initial capacitance after 1,200 charging/discharging cycles. Compared with Co3O4 and NiO nanostructures, the specific capacitance of NiO nanosheets is much better. These characteristics suggest that NiO nanosheet electrodes are promising for energy storage application with high power demands.

Study on the formation of graphene by ion implantation on Cu, Ni and CuNi alloy

NASA Astrophysics Data System (ADS)

Kim, Janghyuk; Kim, Hong-Yeol; Jeon, Jeong Heum; An, Sungjoo; Hong, Jongwon; Kim, Jihyun

2018-09-01

This study identifies the details for direct synthesis of graphene by carbon ion implantation on Cu, Ni and CuNi alloy. Firstly, diffusion and concentration of carbon atoms in Cu and Ni are estimated separately. The concentrations of carbon atoms near the surfaces of Cu and Ni after carbon ion implantation and subsequent thermal annealing were correlated with the number of atoms and with the coverage or thickness of graphene. Systematic experiments showed that the Cu has higher carbon diffusivity and graphene coverage than Ni but higher temperatures and longer annealing times are required to synthesize graphene, similar to those in chemical vapor deposition method. The CuNi system shows better graphene coverage and quality than that on a single metal catalyst even after a short annealing time, as it has larger carbon diffusivity and lower carbon solubility than Ni and shows lower activation energy than Cu.

Solution growth of NiO nanosheets supported on Ni foam as high-performance electrodes for supercapacitors.

PubMed

Yan, Hailong; Zhang, Deyang; Xu, Jinyou; Lu, Yang; Liu, Yunxin; Qiu, Kangwen; Zhang, Yihe; Luo, Yongsong

2014-01-01

Well-aligned nickel oxide (NiO) nanosheets with the thickness of a few nanometers supported on a flexible substrate (Ni foam) have been fabricated by a hydrothermal approach together with a post-annealing treatment. The three-dimensional NiO nanosheets were further used as electrode materials to fabricate supercapacitors, with high specific capacitance of 943.5, 791.2, 613.5, 480, and 457.5 F g(-1) at current densities of 5, 10, 15, 20, and 25 A g(-1), respectively. The NiO nanosheets combined well with the substrate. When the electrode material was bended, it can still retain 91.1% of the initial capacitance after 1,200 charging/discharging cycles. Compared with Co3O4 and NiO nanostructures, the specific capacitance of NiO nanosheets is much better. These characteristics suggest that NiO nanosheet electrodes are promising for energy storage application with high power demands.

NiSe-Ni0.85 Se Heterostructure Nanoflake Arrays on Carbon Paper as Efficient Electrocatalysts for Overall Water Splitting.

PubMed

Chen, Yajie; Ren, Zhiyu; Fu, Huiying; Zhang, Xin; Tian, Guohui; Fu, Honggang

2018-06-01

Fabricating cost-effective, bifunctional electrocatalysts for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in basic media is critical for renewable energy generation. Here, NiSe/CP, Ni 0.85 Se/CP, and NiSe-Ni 0.85 Se/CP heterostructure catalysts with different phase constitutions are successfully prepared through in situ selenylation of a NiO nanoflake array oriented on carbon paper (CP) by tuning the original Ni/Se molar ratio of the raw materials. The relationship between the crystal phase component and electrocatalytic activity is systematically studied. Benefiting from the synergetic effect of the intrinsic metallic state, facile charge transport, abundant catalytic active sites, and multiple electrolyte transmission paths, the optimized NiSe-Ni 0.85 Se/CP exhibits a remarkably higher catalytic activity for both the HER and OER than single-phase NiSe/CP and Ni 0.85 Se/CP. A current density of 10 mA cm -2 at 1.62 V and a high stability can be obtained by using NiSe-Ni 0.85 Se/CP as both the cathode and anode for overall water splitting under alkaline conditions. Density functional theory calculations confirm that H and OH - can be more easily adsorbed on NiSe-Ni 0.85 Se than on NiSe and Ni 0.85 Se. This study paves the way for enhancing the overall water splitting performance of nickel selenides by fabricating heterophase junctions using nickel selenides with different phases. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

GeV ion irradiation of NiFe and NiCo: Insights from MD simulations and experiments

DOE PAGES

Leino, Aleksi A.; Samolyuk, German D.; Sachan, Ritesh; ...

2018-03-31

Concentrated solid solution alloys have attracted rapidly increasing attention due to their potential for designing materials with high tolerance to radiation damage. To tackle the effects of chemical complexity in defect dynamics and radiation response, we present in this paper a computational study on swift heavy ion induced effects in Ni and equiatomic Ni -based alloys (Ni 50Fe 50, Ni 50Co 50) using two-temperature molecular dynamics simulations (2T-MD). The electronic heat conductivity in the two-temperature equations is parameterized from the results of first principles electronic structure calculations. A bismuth ion (1.542 GeV) is selected and single impact simulations performed inmore » each target. We study the heat flow in the electronic subsystem and show that alloying Ni with Co or Fe reduces the heat dissipation from the impact by the electronic subsystem. Simulation results suggest no melting or residual damage in pure Ni while a cylindrical region melts along the ion propagation path in the alloys. In Ni 50Co 50 the damage consists of a dislocation loop structure (d = 2 nm) and isolated point defects, while in Ni 50Fe 50, a defect cluster (d = 4 nm) along the ion path is, in addition, formed. The simulation results are supported by atomic-level structural and defect characterizations in bismuth-irradiated Ni and Ni 50Fe 50. Finally, the significance of the 2T-MD model is demonstrated by comparing the results to those obtained with an instantaneous energy deposition model without consideration of e-ph interactions in pure Ni and by showing that it leads to a different qualitative behavior.« less

GeV ion irradiation of NiFe and NiCo: Insights from MD simulations and experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leino, Aleksi A.; Samolyuk, German D.; Sachan, Ritesh

Concentrated solid solution alloys have attracted rapidly increasing attention due to their potential for designing materials with high tolerance to radiation damage. To tackle the effects of chemical complexity in defect dynamics and radiation response, we present in this paper a computational study on swift heavy ion induced effects in Ni and equiatomic Ni -based alloys (Ni 50Fe 50, Ni 50Co 50) using two-temperature molecular dynamics simulations (2T-MD). The electronic heat conductivity in the two-temperature equations is parameterized from the results of first principles electronic structure calculations. A bismuth ion (1.542 GeV) is selected and single impact simulations performed inmore » each target. We study the heat flow in the electronic subsystem and show that alloying Ni with Co or Fe reduces the heat dissipation from the impact by the electronic subsystem. Simulation results suggest no melting or residual damage in pure Ni while a cylindrical region melts along the ion propagation path in the alloys. In Ni 50Co 50 the damage consists of a dislocation loop structure (d = 2 nm) and isolated point defects, while in Ni 50Fe 50, a defect cluster (d = 4 nm) along the ion path is, in addition, formed. The simulation results are supported by atomic-level structural and defect characterizations in bismuth-irradiated Ni and Ni 50Fe 50. Finally, the significance of the 2T-MD model is demonstrated by comparing the results to those obtained with an instantaneous energy deposition model without consideration of e-ph interactions in pure Ni and by showing that it leads to a different qualitative behavior.« less

Heterobimetallic [NiFe] Complexes Containing Mixed CO/CN- Ligands: Analogs of the Active Site of the [NiFe] Hydrogenases.

PubMed

Perotto, Carlo U; Sodipo, Charlene L; Jones, Graham J; Tidey, Jeremiah P; Blake, Alexander J; Lewis, William; Davies, E Stephen; McMaster, Jonathan; Schröder, Martin

2018-03-05

The development of synthetic analogs of the active sites of [NiFe] hydrogenases remains challenging, and, in spite of the number of complexes featuring a [NiFe] center, those featuring CO and CN - ligands at the Fe center are under-represented. We report herein the synthesis of three bimetallic [NiFe] complexes [Ni( N 2 S 2 )Fe(CO) 2 (CN) 2 ], [Ni( S 4 )Fe(CO) 2 (CN) 2 ], and [Ni( N 2 S 3 )Fe(CO) 2 (CN) 2 ] that each contain a Ni center that bridges through two thiolato S donors to a {Fe(CO) 2 (CN) 2 } unit. X-ray crystallographic studies on [Ni( N 2 S 3 )Fe(CO) 2 (CN) 2 ], supported by DFT calculations, are consistent with a solid-state structure containing distinct molecules in the singlet ( S = 0) and triplet ( S = 1) states. Each cluster exhibits irreversible reduction processes between -1.45 and -1.67 V vs Fc + /Fc and [Ni( N 2 S 3 )Fe(CO) 2 (CN) 2 ] possesses a reversible oxidation process at 0.17 V vs Fc + /Fc. Spectroelectrochemical infrared (IR) and electron paramagnetic resonance (EPR) studies, supported by density functional theory (DFT) calculations, are consistent with a Ni III Fe II formulation for [Ni( N 2 S 3 )Fe(CO) 2 (CN) 2 ] + . The singly occupied molecular orbital (SOMO) in [Ni( N 2 S 3 )Fe(CO) 2 (CN) 2 ] + is based on Ni 3d z 2 and 3p S with the S contributions deriving principally from the apical S-donor. The nature of the SOMO corresponds to that proposed for the Ni-C state of the [NiFe] hydrogenases for which a Ni III Fe II formulation has also been proposed. A comparison of the experimental structures, and the electrochemical and spectroscopic properties of [Ni( N 2 S 3 )Fe(CO) 2 (CN) 2 ] and its [Ni( N 2 S 3 )] precursor, together with calculations on the oxidized [Ni( N 2 S 3 )Fe(CO) 2 (CN) 2 ] + and [Ni( N 2 S 3 )] + forms suggests that the binding of the {Fe(CO)(CN) 2 } unit to the {Ni(CysS) 4 } center at the active site of the [NiFe] hydrogenases suppresses thiolate-based oxidative chemistry involving the bridging thiolate S donors

Transformation characteristics of TiNi/TiNi alloys synthesized by explosive welding

NASA Astrophysics Data System (ADS)

Li, Juntao; Zheng, Yanjun; Cui, Lishan

2007-10-01

Effects of severe deformation and heat treatment on the transformation behaviors of explosively welded duplex TiNi/TiNi shape memory alloys (SMAs) were investigated by the differential scanning calorimeter (DSC). The explosively welded duplex TiNi/TiNi plate of 0.7 mm in thickness was cold-rolled at room temperature to the extent of 60% reduction in thickness and then annealed at different temperatures (573-973 K) for different time (15 min-10 h). Low temperature (623-723 K) heat treatment led to amorphous crystallization. At higher temperature (873 K), the re-crystallization took place in the specimens. Analysis showed that the change of internal stresses is just the root cause of the change of transformation temperature. The relationships between the transformation behaviors and the heat treatment were discussed in the present report.

Structural features of [NiFeSe] and [NiFe] hydrogenases determining their different properties: a computational approach.

PubMed

Baltazar, Carla S A; Teixeira, Vitor H; Soares, Cláudio M

2012-04-01

Hydrogenases are metalloenzymes that catalyze the reversible reaction H(2)<->2H(+) + 2e(-), being potentially useful in H(2) production or oxidation. [NiFeSe] hydrogenases are a particularly interesting subgroup of the [NiFe] class that exhibit tolerance to O(2) inhibition and produce more H(2) than standard [NiFe] hydrogenases. However, the molecular determinants responsible for these properties remain unknown. Hydrophobic pathways for H(2) diffusion have been identified in [NiFe] hydrogenases, as have proton transfer pathways, but they have never been studied in [NiFeSe] hydrogenases. Our aim was, for the first time, to characterize the H(2) and proton pathways in a [NiFeSe] hydrogenase and compare them with those in a standard [NiFe] hydrogenase. We performed molecular dynamics simulations of H(2) diffusion in the [NiFeSe] hydrogenase from Desulfomicrobium baculatum and extended previous simulations of the [NiFe] hydrogenase from Desulfovibrio gigas (Teixeira et al. in Biophys J 91:2035-2045, 2006). The comparison showed that H(2) density near the active site is much higher in [NiFeSe] hydrogenase, which appears to have an alternative route for the access of H(2) to the active site. We have also determined a possible proton transfer pathway in the [NiFeSe] hydrogenase from D. baculatum using continuum electrostatics and Monte Carlo simulation and compared it with the proton pathway we found in the [NiFe] hydrogenase from D. gigas (Teixeira et al. in Proteins 70:1010-1022, 2008). The residues constituting both proton transfer pathways are considerably different, although in the same region of the protein. These results support the hypothesis that some of the special properties of [NiFeSe] hydrogenases could be related to differences in the H(2) and proton pathways. © SBIC 2012

A dithiolate-bridged (CN)2(CO)Fe-Ni complex reproducing the IR bands of [NiFe] hydrogenase.

PubMed

Tanino, Soichiro; Li, Zilong; Ohki, Yasuhiro; Tatsumi, Kazuyuki

2009-03-16

A dithiolate-bridged dinuclear Fe-Ni complex, which has the desired fac-(CN)(2)(CO) ligand set at iron, has been synthesized. Its CN/CO bands in the IR spectrum reproduce those of the Ni-A, Ni-B, and Ni-SU states, which indicate that these octahedral Fe(II) centers have similar electronic properties. This result verifies the assignment of a (CN)(2)(CO)Fe(II) moiety in the active site of [NiFe] hydrogenase.

Nickel recovery from electronic waste II electrodeposition of Ni and Ni-Fe alloys from diluted sulfate solutions.

PubMed

Robotin, B; Ispas, A; Coman, V; Bund, A; Ilea, P

2013-11-01

This study focuses on the electrodeposition of Ni and Ni-Fe alloys from synthetic solutions similar to those obtained by the dissolution of electron gun (an electrical component of cathode ray tubes) waste. The influence of various parameters (pH, electrolyte composition, Ni(2+)/Fe(2+) ratio, current density) on the electrodeposition process was investigated. Scanning electron microscopy (SEM) and X-ray fluorescence analysis (XRFA) were used to provide information about the obtained deposits' thickness, morphology, and elemental composition. By controlling the experimental parameters, the composition of the Ni-Fe alloys can be tailored towards specific applications. Complementarily, the differences in the nucleation mechanisms for Ni, Fe and Ni-Fe deposition from sulfate solutions have been evaluated and discussed using cyclic voltammetry and potential step chronoamperometry. The obtained results suggest a progressive nucleation mechanism for Ni, while for Fe and Ni-Fe, the obtained data points are best fitted to an instantaneous nucleation model. Copyright © 2013 Elsevier Ltd. All rights reserved.

Fe-Ni-bearing serpentines from the saprolite horizon of Caribbean Ni-laterite deposits: new insights from thermodynamic calculations

NASA Astrophysics Data System (ADS)

Villanova-de-Benavent, Cristina; Domènech, Cristina; Tauler, Esperança; Galí, Salvador; Tassara, Santiago; Proenza, Joaquín A.

2017-10-01

Fe-Ni-bearing serpentine from the saprolite horizon is the main Ni ores in hydrous silicate-type Ni laterites and formed by chemical weathering of partially serpentinized ultramafic rocks under tropical conditions. During lateritization, Mg, Si, and Ni are leached from the surface and transported downwards. Fe2+ is oxidized to Fe3+ and fixed as insoluble Fe-oxyhydroxides (mostly goethite) that incorporate Ni. This Ni is later leached from goethite and incorporated in secondary serpentine and garnierite. As a result, a serpentine-dominated saprolite horizon forms over the ultramafic protolith, overlapped by a Fe-oxyhydroxide-dominated limonite horizon. The serpentine from the protolith (serpentine I) is of hydrothermal origin and yields similar Ni (0.10-0.62 wt.% NiO) and lower Fe (mostly 1.37-5.81 wt.% FeO) concentrations than the primary olivine. In contrast, Fe-Ni-bearing serpentine from the saprolite (serpentine II) shows significantly higher and variable Fe and Ni contents, typically ranging from 2.23 to 15.59 wt.% Fe2O3 and from 1.30 to 7.67 wt.% NiO, suggesting that serpentine get enriched in Fe and Ni under supergene conditions. This study presents detailed mineralogical, textural, and chemical data on this serpentine II, as well as new insights by thermodynamic calculations assuming ideal solution between Fe-, Ni- and Mg-pure serpentines. The aim is to assess if at atmospheric pressure and temperature Fe-Ni-bearing serpentine can be formed by precipitation. Results indicate that the formation of serpentine II under atmospheric pressure and temperature is thermodynamically supported, and pH, Eh, and the equilibrium constant of the reaction are the parameters that affect the results more significantly.

Effect of Thermal Treatments on Ni-Mn-Ga and Ni-Rich Ni-Ti-Hf/Zr High-Temperature Shape Memory Alloys

NASA Astrophysics Data System (ADS)

Santamarta, Ruben; Evirgen, Alper; Perez-Sierra, Aquilina M.; Pons, Jaume; Cesari, Eduard; Karaman, Ibrahim; Noebe, Ron D.

2015-11-01

Among all the promising high-temperature shape memory alloys (HTSMAs), the Ni-Mn-Ga and the Ni-Ti-Hf/Zr systems exhibit interesting shape memory and superelastic properties that may place them in a good position for potential applications. The present work shows that thermal treatments play a crucial role in controlling the martensitic phase transformation characteristics of both systems, but in different ways. On one hand, the equilibrium phase diagram of the Ni-Mn-Ga family allows selecting compositions with high transformation temperatures and outstanding thermal stability at relatively high temperatures in air, showing no significant changes in the transformation behavior for continuous aging up to ˜5 years at 500 °C. Moreover, the excellent thermal stability correlates with a good thermal cyclic stability and an exceptional oxidation resistance of the parent phase. On the other hand, precipitation processes controlled by thermal treatments are needed to manipulate the transformation temperatures, mechanical properties, and thermal stability of Ni-rich Ni-Ti-Hf/Zr alloys to become HTSMAs. These changes in the functional properties are a consequence of the competition between the mechanical and compositional effects of the precipitates on the martensitic transformation.

Solution growth of NiO nanosheets supported on Ni foam as high-performance electrodes for supercapacitors

PubMed Central

2014-01-01

Well-aligned nickel oxide (NiO) nanosheets with the thickness of a few nanometers supported on a flexible substrate (Ni foam) have been fabricated by a hydrothermal approach together with a post-annealing treatment. The three-dimensional NiO nanosheets were further used as electrode materials to fabricate supercapacitors, with high specific capacitance of 943.5, 791.2, 613.5, 480, and 457.5 F g-1 at current densities of 5, 10, 15, 20, and 25 A g-1, respectively. The NiO nanosheets combined well with the substrate. When the electrode material was bended, it can still retain 91.1% of the initial capacitance after 1,200 charging/discharging cycles. Compared with Co3O4 and NiO nanostructures, the specific capacitance of NiO nanosheets is much better. These characteristics suggest that NiO nanosheet electrodes are promising for energy storage application with high power demands. PMID:25276099

Impact of psychosocial factors on functional improvement in Latino older adults after Tai Chi exercise.

PubMed

Siu, Ka-Chun; Rajaram, Shireen S; Padilla, Carolina

2015-01-01

Increasing evidence underscores the health benefits of Tai Chi (TC), although there is limited evidence of benefits among racial and ethnic minorities. This study investigated the impact of psychosocial status on balance among 23 Latino seniors after a twice-a-week, 12-week TC exercise program. Functional status was measured at baseline, immediately after, and three months following the TC exercise program, using the Timed Up and Go Test and Tinetti Falls Efficacy Scale. Psychosocial status was measured at baseline by the Center for Epidemiologic Studies Depression Scale and Norbeck Social Support Questionnaire. Both measures of functional status improved and were sustained after three months of TC. Greater improvement was significantly related to a higher level of baseline social support. More depressed seniors reported less fear of falling after TC. Depression and social support are important moderators of functional improvement after TC among Latino seniors.

Contributions and source identification of biogenic and anthropogenic hydrocarbons to secondary organic aerosols at Mt. Tai in 2014.

PubMed

Zhu, Yanhong; Yang, Lingxiao; Kawamura, Kimitaka; Chen, Jianmin; Ono, Kaori; Wang, Xinfeng; Xue, Likun; Wang, Wenxing

2017-01-01

Ambient fine particulate matter (PM 2.5 ) and volatile organic compounds (VOCs) collected at Mt. Tai in summer 2014 were analysed and the data were used to identify the contribution of biogenic and anthropogenic hydrocarbons to secondary organic aerosols (SOA) and their sources and potential source areas in high mountain regions. Compared with those in 2006, the 2014 anthropogenic SOA tracers in PM 2.5 aerosols and VOC species related to vehicular emissions exhibited higher concentrations, whereas the levels of biogenic SOA tracers were lower, possibly due to decreased biomass burning. Using the SOA tracer and parameterisation method, we estimated the contributions from biogenic and anthropogenic VOCs, respectively. The results showed that the average concentration of biogenic SOA was 1.08 ± 0.51 μg m -3 , among which isoprene SOA tracers were dominant. The anthropogenic VOC-derived SOA were 7.03 ± 1.21 μg m -3 and 1.92 ± 1.34 μg m -3 under low- and high-NO x conditions, respectively, and aromatics made the greatest contribution. However, the sum of biogenic and anthropogenic SOA only contributed 18.1-49.1% of the total SOA. Source apportionment by positive matrix factorisation (PMF) revealed that secondary oxidation and biomass burning were the major sources of biogenic SOA tracers. Anthropogenic aromatics mainly came from solvent use, fuel and plastics combustion and vehicular emissions. However, for > C6 alkanes and cycloalkanes, vehicular emissions and fuel and plastics combustion were the most important contributors. The potential source contribution function (PSCF) identified the Bohai Sea Region (BSR) as the major source area for organic aerosol compounds and VOC species at Mt. Tai. Copyright © 2016 Elsevier Ltd. All rights reserved.

Climate Prediction Center - El Niño/La Niña Home

Science.gov Websites

Composites Cold and Warm episodes (by season) U.S. La Niña Precipitation & Temperature Impacts U.S. El Niño Precipitation & Temperature Impacts U.S. El Niño State Seasonal Precipitation & ; Temperature Impacts Expert Assessment Current Diagnostic Discussion Monitoring & Data Weekly UpdateFigures

Bone Cell–materials Interactions and Ni Ion Release of Anodized Equiatomic NiTi Alloy

PubMed Central

Bernard, Sheldon A.; Balla, Vamsi Krishna; Davies, Neal M.; Bose, Susmita; Bandyopadhyay, Amit

2011-01-01

Laser processed NiTi alloy was anodized for different durations in H2SO4 electrolyte with varying pH to create biocompatible surfaces with low Ni ion release as well as bioactive surfaces to enhance biocompatibility and bone cell-materials interactions. The anodized surfaces were assessed for their in vitro cell-materials interactions using human fetal osteoblast (hFOB) cells for 3, 7 and 11 days, and Ni ion release up to 8 weeks in simulated body fluids. The results were correlated with surface morphologies of anodized surfaces characterized using field-emission scanning electron microscopy (FESEM). The results show that the anodization creates a surface with nano/micro roughness depending on anodization conditions. The hydrophilicity of NiTi surface was found to improve after anodization due to lower contact angles in cell media, which dropped from 32° to < 5°. The improved wettability of anodized surfaces is further corroborated by their high surface energy comparable to that of cp Ti. Relatively high surface energy, especially polar component, and nano/micro surface features of anodized surfaces significantly increased the number of living cells and their adherence and growth on these surfaces. Finally, a significant drop in Ni ion release from 268 ± 11 to 136 ± 15 ppb was observed for NiTi surfaces after anodization. This work indicates that anodization of NiTi alloy has a positive influence on the surface energy and surface morphology, which in turn improve bone cell-materials interactions and reduce Ni ion release in vitro. PMID:21232641

Effect of heat treatment on morphology evolution of Ti2Ni phase in Ti-Ni-Al-Zr alloy

NASA Astrophysics Data System (ADS)

Sheng, Liyuan; Yang, Yang; Xi, Tingfei

2018-03-01

The Ti6Al2Zr alloy with 15 wt.% Ni addition was prepared and then heat treated in the research. The microstructure of the alloy and evolution of Ti2Ni precipitate were investigated. The microstructure observations demonstrate that the Ni addition could promote the formation of eutectoid and eutectic structures in Ti-Al-Zr alloy. In the eutectoid structure, the ultrafine Ti2Ni fiber precipitates in the α-Ti matrix, but in the eutectic structure, the fine α-Ti phases precipitate in the Ti2Ni matrix. The heat treatment could change the morphology of Ti2Ni precipitates by thinning, fragmenting, merging and spherizing. In the alloy heat treated at and below 1073K, the coarsening of α-Ti precipitates in eutectic structure and Ti2Ni precipitates in eutectoid structure is the mainly characteristic. In the alloy heat treated above 1073K, the phase transformation of α to β phase is the main characteristic, which changes the morphology and amount of Ti2Ni phase by the solid solution of Ni. The phase transformation temperature of Ti-Ni-Al-Zr alloy is between 1073-1123K, which is increased compared with that of the Ti-Ni binary phase diagram.

Electronic circuits having NiAl and Ni.sub.3 Al substrates

DOEpatents

Deevi, Seetharama C.; Sikka, Vinod K.

1999-01-01

An electronic circuit component having improved mechanical properties and thermal conductivity comprises NiAl and/or Ni.sub.3 Al, upon which an alumina layer is formed prior to applying the conductive elements. Additional layers of copper-aluminum alloy or copper further improve mechanical strength and thermal conductivity.

Constitution of the Sr-Ni-O system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zinkevich, M.

2005-09-15

The constitution of the Sr-Ni-O system was studied experimentally for the first time. Samples were prepared either from SrCO{sub 3} and NiO or from Sr(NO{sub 3}){sub 2} and Ni(NO{sub 3}){sub 2}.6H{sub 2}O and characterized by high-temperature X-ray powder diffraction, scanning electron microscopy, thermogravimetric and differential thermal analyses. In the SrO-NiO quasibinary system an eutectic reaction: liquid-bar SrO+NiO was found to occur at 1396+/-5{sup o}C, while the homogeneity range of terminal solid solutions is negligible. Thermodynamic calculations using the regular solution model for the liquid and rocksalt-type phases were employed to predict liquidus and solidus curves. Three ternary compounds, SrNiO{sub 2.5},more » Sr{sub 5}Ni{sub 4}O{sub 11}, and Sr{sub 9}Ni{sub 7}O{sub 21} were observed in the samples prepared from nitrate solutions, but only Sr{sub 9}Ni{sub 7}O{sub 21} was proved to be thermodynamically stable in air up to 1030+/-6{sup o}C. When heating in air, SrNiO{sub 2.5} and Sr{sub 5}Ni{sub 4}O{sub 11} were found to transform irreversibly into a mixture of Sr{sub 9}Ni{sub 7}O{sub 21} and NiO. Isothermal section of the SrO-NiO-O subsystem, which represents phase equilibria at 950-1030{sup o}C as well as an isobaric section of the Sr-Ni-O system in air were constructed.« less

The fabrication of foam-like 3D mesoporous NiO-Ni as anode for high performance Li-ion batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Peng, E-mail: huangp07@lzu.edu.cn; Department of Physics, Lanzhou University, Lanzhou 730000; Zhang, Xin

2015-03-15

Graphical abstract: Foam-like 3 dimensional (3D) mesoporous NiO on 3D micro-porous Ni was fabricated. - Highlights: • We prepare NiO-Ni foam composite via hydrothermal etching and subsequent annealing. • The NiO exhibits novel foam-like 3D mesoporous architecture. • The NiO-Ni anode shows good cycle stability. - Abstract: Foam-like three dimensional mesoporous NiO on Ni foam was fabricated via facile hydrothermal etching and subsequent annealing treatment. The porous NiO consists of a large number of nanosheets with mean thickness about 50 nm, among which a large number of mesoscopic pores with size ranges from 100 nm to 1 μm distribute. Themore » electrochemical performance of the as-prepared NiO-Ni as anode for lithium ion battery was studied by conventional charge/discharge test, which shows excellent cycle stability and rate capability. It exhibits initial discharge and charge capacities of 979 and 707 mA h g{sup −1} at a charge/discharge rate of 0.7 C, which maintain of 747 and 738 mA h g{sup −1} after 100 cycles. Even after 60 cycles at various rates from 0.06 to 14 C, the 10th discharge and charge capacities of the NiO-Ni electrode can revert to 699 and 683 mA h g{sup −1} when lowering the charge/discharge rate to 0.06 C.« less

Ni-MH spent batteries: a raw material to produce Ni-Co alloys.

PubMed

Lupi, Carla; Pilone, Daniela

2002-01-01

Ni-MH spent batteries are heterogeneous and complex materials, so any kind of metallurgical recovery process needs a mechanical pre-treatment at least to separate irony materials and recyclable plastic materials (like ABS) respectively, in order to get additional profit from this saleable scrap, as well as minimize waste arising from the braking separation process. Pyrometallurgical processing is not suitable to treat Ni-MH batteries mainly because of Rare Earths losses in the slag. On the other hand, the hydrometallurgical method, that offers better opportunities in terms of recovery yield and higher purity of Ni, Co, and RE, requires several process steps as shown in technical literature. The main problems during leach liquor purification are the removal of elements such as Mn, Zn, Cd, dissolved during the leaching step, and the separation of Ni from Co. In the present work, the latter problem is overcome by co-deposition of a Ni-35/40%w Co alloy of good quality. The experiments carried out in a laboratory scale pilot-plant show that a current efficiency higher than 91% can be reached in long duration electrowinning tests performed at 50 degrees C and 4.3 catholyte pH.

Synthesis, characterization and some properties of mononuclear Ni and trinuclear NiFe2 complexes related to the active site of [NiFe]-hydrogenases.

PubMed

Song, Li-Cheng; Sun, Xiao-Jing; Zhao, Pei-Hua; Li, Jia-Peng; Song, Hai-Bin

2012-08-07

The [N(2)S(2)]-type ligand 1,2-(2-C(5)H(4)NCH(2)S)(2)C(6)H(4) (L) is prepared in 84% yield by a new method and its structure has been confirmed by X-ray crystallography. The new synthetic method involves sequential reaction of 1,2-phenylenedithiol with EtONa followed by treatment of the resulting disodium salt of 1,2-phenylenedithiol with in situ generated 2-(chloromethyl)pyridine from its HCl salt. Further treatment of ligand L with NiCl(2)·6H(2)O or NiI(2) affords the expected new mononuclear Ni complexes Ni[1,2-(2-C(5)H(4)NCH(2)S)(2)C(6)H(4)]Cl(2) (1) and Ni[1,2-(2-C(5)H(4)NCH(2)S)(2)C(6)H(4)]I(2) (3) in 87-88% yields, whereas reaction of L with NiBr(2) under similar conditions results in formation of the expected new mononuclear complex Ni[1,2-(2-C(5)H(4)NCH(2)S)(2)C(6)H(4)]Br(2) (2) and one unexpected new mononuclear complex Ni[1-(2-C(5)H(4)NCH(2)S)-2-(2-C(5)H(4)NCH(2)SC(6)H(4)S)C(6)H(4)]Br(2) (2*) in 82% and 5% yields, respectively. More interestingly, the ligand L-containing novel trinuclear NiFe(2) complex Ni{[1,2-(2-C(5)H(4)NCH(2)S)(2)C(6)H(4)}Fe(2)(CO)(6)(μ(3)-S)(2) (4) is found to be prepared by sequential reaction of (μ-S(2))Fe(2)(CO)(6) with Et(3)BHLi, followed by treatment of the resulting (μ-LiS)(2)Fe(2)(CO)(6) with mononuclear complex 1, 2, or 3 in 12-20% yields. The new complexes 1-4 and 2* are fully characterized by elemental analysis and various spectroscopies, and the crystal structures of 1, 2* and 3 as well as some electrochemical properties of 1-4 are also reported.

Tai Chi with mental imagery theory improves soleus H-reflex and nerve conduction velocity in patients with type 2 diabetes.

PubMed

Alsubiheen, Abdulrahman; Petrofsky, Jerrold; Daher, Noha; Lohman, Everett; Balbas, Edward; Lee, Haneul

2017-04-01

Diabetes is a disease that leads to damage to the peripheral nerves which may eventually cause balance instability. The purpose of this study was to determine the effect of 8 weeks of Tai Chi (TC) training combined with mental imagery (MI) on soleus H-reflex and nerve conduction velocity (NCV) of the sural and superficial peroneal nerves in people with diabetes. Quasi-experimental, one group pretest-posttest design. Human Research Laboratory. A series of Yang style of Tai Chi classes with mental imagery, one hour, two sessions per week for 8 weeks was done. The Activities-specific Balance Confidence (ABC) Scale, Functional Reach Test (FRT), and One Leg Standing Test (OLS) were measured as functional data. Hoffman reflex (H-reflex), and sural and superficial peroneal NCV were measured as main outcomes. All functional outcomes measures were significantly improved after the intervention (p<0.01). In the H-reflex, there was a significant increase in amplitude (μV) after completing 8 weeks of TC exercise (p=0.02). In the sural nerve, the velocity (p=0.01), amplitude (p=0.01), and latency (p=0.01) were significantly improved between pre and post-test. In the superficial peroneal nerve, significant improvements were observed in (p=0.02) and latency (p=0.01), but not in amplitude (μV) (p>0.05). Combining TC intervention with MI theory showed an improvement in the H-reflex and NCV tests, which suggests improved balance and walking stability. Copyright © 2017 Elsevier Ltd. All rights reserved.

Radiation damage buildup and dislocation evolution in Ni and equiatomic multicomponent Ni-based alloys

NASA Astrophysics Data System (ADS)

Levo, E.; Granberg, F.; Fridlund, C.; Nordlund, K.; Djurabekova, F.

2017-07-01

Single-phase multicomponent alloys of equal atomic concentrations ("equiatomic") have proven to exhibit promising mechanical and corrosion resistance properties, that are sought after in materials intended for use in hazardous environments like next-generation nuclear reactors. In this article, we investigate the damage production and dislocation mobility by simulating irradiation of elemental Ni and the alloys NiCo, NiCoCr, NiCoFe and NiFe, to assess the effect of elemental composition. We compare the defect production and the evolution of dislocation networks in the simulation cells of two different sizes, for all five studied materials. We find that the trends in defect evolution are in good agreement between the different cell sizes. The damage is generally reduced with increased alloy complexity, and the dislocation evolution is specific to each material, depending on its complexity. We show that increasing complexity of the alloys does not always lead to decreased susceptibility to damage accumulation under irradiation. We show that, for instance, the NiCo alloy behaves very similarly to Ni, while presence of Fe or Cr in the alloy even as a third component reduces the saturated level of damage substantially. Moreover, we linked the defect evolution with the dislocation transformations in the alloys. Sudden drops in defect number and large defect fluctuations from the continuous irradiation can be explained from the dislocation activity.

One-pot fabrication of NiFe2O4 nanoparticles on α-Ni(OH)2 nanosheet for enhanced water oxidation

NASA Astrophysics Data System (ADS)

Chen, Hong; Yan, Junqing; Wu, Huan; Zhang, Yunxia; Liu, Shengzhong (Frank)

2016-08-01

Water splitting has been intensively investigated as a promising solution to resolve the future environmental and energy crises. The oxygen evolution reaction (OER) of the photo- and electric field-induced water splitting limits the development of other reactions, including hydrogen evolution reaction (HER). Fe, Ni and NiFe (hydro) oxide-based catalysts are generally acknowledged among the best candidates of OER catalysts for water splitting. Herein, we developed a one-pot simple hydrothermal process to assemble NiFe2O4 nanoparticles onto the α-Ni(OH)2 nanosheets. The first formed NiFe2O4 under high temperature and pressure environment induces and assists the α-Ni(OH)2 formation without any further additives, because the distance between the neighboring Ni atoms in the cubic NiFe2O4 is similar to that in the α-Ni(OH)2 {003} facets. We have synthesized a series of NiFe2O4/α-Ni(OH)2 compounds and find that the overpotential decreases with the increase of Ni(OH)2 content while the OER kinetics stays unchanged, suggesting that Ni(OH)2 plays a major role in overpotential while NiFe2O4 mainly affects the OER kinetics. The obtained NiFe2O4/α-Ni(OH)2 compounds is also found to be a promising co-catalyst for the photocatalytic water oxidation. In fact, it is even more active than the noble PtOx with acceptable stability for the oxygen generation.

Electromigration effect upon the Sn-0.7 wt% Cu/Ni and Sn-3.5 wt% Ag/Ni interfacial reactions

NASA Astrophysics Data System (ADS)

Chen, Chih-ming; Chen, Sinn-wen

2001-08-01

This study investigates the effect of electromigration upon the interfacial reactions between the promising lead-free solders, Sn-Cu and Sn-Ag, with Ni substrate. Sandwich-type reaction couples, Sn-0.7 wt% Cu/Ni/Sn-0.7 wt% Cu and Sn-3.5 wt% Ag/Ni/Sn-3.5 wt% Ag, were reacted at 160, 180, and 200 °C for various lengths of time with and without the passage of electric currents. Without passage of electric currents through the couples, only one intermetallic compound Ni3Sn4 with ˜7 at. % Cu solubility was found at both interfaces of the Sn-0.7 wt% Cu/Ni couples. With the passage of an electric current of 500 A/cm2 density, the Cu6Sn5 phase was formed at the solder/Ni interface besides the Ni3Sn4 phase. Similar to those without the passage of electric currents, only the Ni3Sn4 phase was found at the Ni/solder interface. Directions of movement of electrons, Sn, and Cu atoms are the same at the solder/Ni interface, and the growth rates of the intermetallic layers were enhanced. At the Ni/solder interface, the electrons flow in the opposite direction of the Sn and Cu movement, and the growth rates of the intermetallic layers were retarded. Only the Ni3Sn4 phase was formed from the Sn-3.5 wt% Ag/Ni interfacial reaction with and without the passage of electric currents. Similar to the Sn-0.7 wt% Cu/Ni system, the movement of electrons enhances or retards the growth rates of the intermetallic layers at the solder/Ni and Ni/solder interfaces, respectively. Calculation results show the apparent effective charge za* decreases in magnitude with raising temperatures, which indicates the electromigration effect becomes insignificant at higher temperatures.

3D Computer Models of T- x- y Diagrams, Forming the Fe-Ni-Co-FeS-NiS-CoS Subsystem

NASA Astrophysics Data System (ADS)

Lutsyk, V. I.; Vorob'eva, V. P.

2017-12-01

3D computer models of Fe-Ni-Co, Fe-Ni-FeS-NiS, Fe-Co-FeS-CoS, Ni-Co-NiS-CoS T- x- y diagrams have been designed. The geometric structure (35 surfaces, two-phase surface of the reaction type change, 17 phase regions) of the Fe-Ni-FeS-NiS T- x- y diagram is investigated in detail. The liquidus hypersurfaces prediction of the Fe-Ni-Co-FeS-NiS-CoS subsystem is represented.

Template-Mediated Ni(II) Dispersion in Mesoporous SiO2 for Preparation of Highly Dispersed Ni Catalysts: Influence of Template Type.

PubMed

Ning, Xin; Lu, Yiyuan; Fu, Heyun; Wan, Haiqin; Xu, Zhaoyi; Zheng, Shourong

2017-06-07

Supported Ni catalysts on three mesoporous SiO 2 supports (i.e., SBA-15, MCM-41, and HMS) were prepared using a solid-state reaction between Ni(NO 3 ) 2 and organic template-occluded mesoporous SiO 2 . For comparison, supported Ni catalysts on mesoporous SiO 2 synthesized by the conventional impregnation method were also included. The catalysts were characterized by scanning electron microscopy, X-ray diffraction, UV-vis diffuse reflectance spectroscopy, N 2 adsorption, X-ray photoelectron spectroscopy, H 2 temperature-programmed reduction, transmission electron microscopy, and transmission electron microscopy-energy-dispersive X-ray. The catalytic properties of the catalysts were evaluated using gas-phase catalytic hydrodechlorination of 1,2-dichloroethane. The results showed that upon grinding Ni(NO 3 ) 2 with template-occluded mesoporous SiO 2 , strong coordination between Ni 2+ and dodecylamine was identified in the Ni(NO 3 ) 2 -HMS system. Additionally, the results of H 2 temperature-programmed reduction revealed that NiO in calcined NiO/HMS was reduced at higher temperature than those in calcined NiO/SBA-15 and NiO/MCM-41, reflecting the presence of a strong interaction between NiO and mesoporous SiO 2 in NiO/HMS. Consistently, the average particle sizes of metallic Ni were found to be 2.7, 3.4, and 9.6 nm in H 2 -reduced Ni/HMS, Ni/SBA-15, and Ni/MCM-41, respectively, indicative of a much higher Ni dispersion in Ni/HMS. For the catalytic hydrodechlorination of 1,2-dichloroethane, Ni/MCM-41 synthesized by the solid-state reaction method exhibited a catalytic activity similar to that prepared by the impregnation method, while higher catalytic activities were observed on Ni/HMS and Ni/SBA-15 than on their counterparts prepared by the impregnation method. Furthermore, a higher conversion was identified on Ni/HMS than on Ni/SBA-15 and Ni/MCM-41, highlighting the importance of template type for the preparation of highly dispersed metal catalysts on mesoporous Si

Capture of Hydrogen Using ZrNi

NASA Technical Reports Server (NTRS)

Patton, Lisa; Wales, Joshua; Lynch, David; Parrish, Clyde

2005-01-01

Water, as ice, is thought to reside in craters at the lunar poles along with CH4 and H2 . A proposed robotic mission for 2012 will utilize metal/metal hydrides for H2 recovery. Specifications are 99% capture of H2 initially at 5 bar and 100C (or greater), and degassing completely at 300C. Of 47-systems examined using the van't Hoff equation, 4 systems, Mg/MgH2, Mg2Ni/Mg2NiH4, ZrNi/ZrNiH2.8, and Pd/PdH0.77, were considered likely candidates for further examination. It is essential, when selecting a system, to also examine questions regarding activation, kinetics, cyclic stability, and gas impurity effects. After considering those issues, ZrN1 was selected as the most promising candidate, as it is easily activated and rapidly forms ZrNiH 2.8 . In addition, it resists oxide poisoning by CO2, and H2O, while some oxidation by O2 is recommended for improved activation . The presence of hydrogen in the as received Zr-Ni alloy from Alfa Aesar posed additional technical problems. X-ray diffraction of the Zr-Ni powder (-325 mesh), with a Zr:Ni wt% ratio of 70:30, was found to consist of ZrH2, ZrNiH2.8, and ZrNi. ZrH2 in the alloy presented the risk that after degassing that both Zr and ZrNi would be present, and thus lead to erroneous results regarding the reactivity of ZrNi with H2 . Fortunately, ZrH2 is a highly stable hydride that does not degas H2 to any significant extent at temperatures below 300C. Based on equilibrium calculations for the decomposition of ZrH2, only 1 millionth of the hydride decomposed at 300C under a N2 atmosphere flowing at 25 ccm for 64 hours, the longest time for pretreatment employed in the investigation. It was possible, from the X-ray results and knowledge of the Zr:Ni ratio, to compute the composition of a pretreated specimen as being 76 wt% ZrNi and the balance ZrH2.

The crystal structures of Ni{sub 3+x}Sn{sub 4}Zn and Ni{sub 6+x}Sn{sub 8}Zn and their structural relations to Ni{sub 3+x}Sn{sub 4}, NiSn and Ni{sub 5−δ}ZnSn{sub 4}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schmetterer, Clemens, E-mail: clemens.schmetterer@univie.ac.at; Effenberger, Herta Silvia; Rajamohan, Divakar

2016-06-15

The crystal structures of two new compounds were determined from single-crystal X-ray diffraction measurements: Ni{sub 3+x}Sn{sub 4}Zn, (x~1.35, a=7.110(2) Å, b=4.123(1) Å, c=10.346(3) Å, β=90.23(2)°, space group I2/m, Z=2. R1=0.025, wR2=0.059 for 748 unique reflections, 35 variable parameters) and Ni{sub 6+x}Sn{sub 8}Zn, x~1.35 (a=12.379(3) Å, b=4.095(1) Å, c=12.155(3) Å, β=116.25(3)°, space group C2/m, Z=2. R1=0.026, wR2=0.052 for 1346 unique reflections, 60 variable parameters). In addition, a structural refinement was performed for Ni{sub 3+x}Sn{sub 4}, x~0.13 (a=12.264(3) Å, b=4.066(1) Å, c=5.223(2) Å, β=104.85(3)°, space group C2/m, Z=2. R1=0.019, wR2=0.046 for 617 unique reflections, 29 variable parameters). The three compounds show pronouncedmore » similarities among each other as well as to the crystal structures of surrounding binary Ni–Sn and ternary Ni–Sn–Zn compounds. In particular, the two new compounds form a homologous series with Ni{sub 3+x}Sn{sub 4}, x~0.13. They contain “Ni{sub 4}Sn{sub 4}” and “Ni{sub 2}Sn{sub 4}” building blocks which by different interconnection build up the distinct structures. Topological relations with NiSn and Ni{sub 5−δ}Sn{sub 4}Zn, δ~0.25 are evident. - Graphical abstract: Projection of the structure of Ni{sub 6+x}ZnSn{sub 8}, x~1.35 and constituent building blocks. Display Omitted - Highlights: • The crystal structures of Ni{sub 6+x}Sn{sub 8}Zn and Ni{sub 3+x}Sn{sub 4}Zn were determined using single crystal XRD. • Topological relations to Ni–Sn and Ni–Sn–Zn compounds were established and discussed. • Common structural units were identified and their interconnection patterns described.« less

Selective oxidation of cube textured Ni and Ni-Cr substrate for the formation of cube textured NiO as a component buffer layer for REBa 2Cu 3O 7+ x (REBCO) coated conductors

NASA Astrophysics Data System (ADS)

Lockman, Z.; Goldacker, W.; Nast, R.; deBoer, B.; MacManus-Driscoll, J. L.

2002-08-01

Thermal oxidation of cube textured, pure Ni and Ni-Cr tapes was undertaken under different oxidation conditions to form cube textured NiO for the use as a first component of buffer layer for the coated conductor. Cube textured NiO was formed on pure Ni after oxidising for more than 130 min in O 2 at 1250 °C. The oxide thickness was >30 μm. Much shorter oxidation times (20-40 min, NiO thickness of ∼5 μm) and lower temperature (1050 °C) were required to form a similar texture on Ni-Cr foils. In addition, NiO formed on Ni-13%Cr was more highly textured than Ni-10%Cr. A Cr 2O 3 inner layer and NiO outer layer was formed on the Ni-Cr alloys.

Synergetic interface between NiO/Ni3S2 nanosheets and carbon nanofiber as binder-free anode for highly reversible lithium storage

NASA Astrophysics Data System (ADS)

Jiang, Jialin; Ma, Chao; Yang, Yinbo; Ding, Jingjing; Ji, Hongmei; Shi, Shaojun; Yang, Gang

2018-05-01

A novel heterostructure of NiO/Ni3S2 nanoflake is synthesized and composited with carbon nanofibers (CNF) membrane. NiO/Ni3S2 nanoflakes are homogeneously dispersed in CNF network, herein, NiO/Ni3S2 like leaf and CNF like branch. Carbon nanofibers network efficiently prevents the pulverization and buffers the volume changes of NiO/Ni3S2, meanwhile, NiO/Ni3S2 nanoflakes through the conductive channels of carbon nanofibers own improved Li+ diffusion ability and structural stability. The capacity of NiO/Ni3S2/CNF reaches to 519.2 mA g-1 after 200 cycles at the current density of 0.5 A g-1 while NiO/Ni3S2 fades to 71 mAh g-1 after 40 cycles. Owing to the synergetic structure, the resultant binder-free electrode NiO/Ni3S2/carbon nanofibers shows an excellent reversible lithium storage capability.

Rationally-designed configuration of directly-coated Ni 3S 2/Ni electrode by RGO providing superior sodium storage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Xiaosheng; Li, Xifei; Bai, Zhimin

Designing nanocomposite materials is an effective approach for enhancing the performance of sodium-ion batteries (SIBs), and understanding the synergy among components is critically important for new, better materials design. Here in this paper, a directly reduced graphene oxide (RGO) decorated anode electrode was designed and tested for SIBs, in which uniform RGO coating onto the Ni 3S 2/Ni electrode was realized using facile hydrothermal reactions. The results indicate that the RGO/Ni 3S 2/Ni electrode delivers a high reversible specific capacity of 448.6 mAh g -1, high capacity retention of 96.5% after 100 cycles, and excellent rate capability of 263.1 mAhmore » g -1 at 800 mA g -1. Compared with the Ni 3S 2/Ni electrode, the improved performance of the RGO/Ni 3S 2/Ni electrode benefits from RGO-promoted displacement reaction of Ni 3S 2 with sodium. DFT calculations reveal that the RGO layer can significantly improve the electron mobility of the RGO/Ni 3S 2 + Na structure, and the hybrid interaction between the extraneous p orbits of C and indigenous p and d orbits of Ni, as well as p orbits of S is the major reason for why RGO can improve the electrical transport properties.« less

Rationally-designed configuration of directly-coated Ni 3S 2/Ni electrode by RGO providing superior sodium storage

DOE PAGES

Song, Xiaosheng; Li, Xifei; Bai, Zhimin; ...

2018-02-28

Designing nanocomposite materials is an effective approach for enhancing the performance of sodium-ion batteries (SIBs), and understanding the synergy among components is critically important for new, better materials design. Here in this paper, a directly reduced graphene oxide (RGO) decorated anode electrode was designed and tested for SIBs, in which uniform RGO coating onto the Ni 3S 2/Ni electrode was realized using facile hydrothermal reactions. The results indicate that the RGO/Ni 3S 2/Ni electrode delivers a high reversible specific capacity of 448.6 mAh g -1, high capacity retention of 96.5% after 100 cycles, and excellent rate capability of 263.1 mAhmore » g -1 at 800 mA g -1. Compared with the Ni 3S 2/Ni electrode, the improved performance of the RGO/Ni 3S 2/Ni electrode benefits from RGO-promoted displacement reaction of Ni 3S 2 with sodium. DFT calculations reveal that the RGO layer can significantly improve the electron mobility of the RGO/Ni 3S 2 + Na structure, and the hybrid interaction between the extraneous p orbits of C and indigenous p and d orbits of Ni, as well as p orbits of S is the major reason for why RGO can improve the electrical transport properties.« less

Bone cell-materials interactions and Ni ion release of anodized equiatomic NiTi alloy.

PubMed

Bernard, Sheldon A; Balla, Vamsi Krishna; Davies, Neal M; Bose, Susmita; Bandyopadhyay, Amit

2011-04-01

A laser processed NiTi alloy was anodized for different times in H(2)SO(4) electrolyte with varying pH to create biocompatible surfaces with low Ni ion release as well as bioactive surfaces to enhance biocompatibility and bone cell-material interactions. The anodized surfaces were assessed for their in vitro cell-material interactions using human fetal osteoblast (hFOB) cells for 3, 7 and 11 days, and Ni ion release up to 8 weeks in simulated body fluids. The results were correlated with the surface morphologies of anodized surfaces characterized using field-emission scanning electron microscopy (FESEM). The results show that anodization creates a surface with nano/micro-roughness depending on the anodization conditions. The hydrophilicity of the NiTi surface was found to improve after anodization, as shown by the lower contact angles in cell medium, which dropped from 32° to <5°. The improved wettability of anodized surfaces is further corroborated by their high surface energy, comparable with that of commercially pure Ti. Relatively high surface energies, especially the polar component, and nano/micro surface features of anodized surfaces significantly increased the number of living cells and their adherence and growth on these surfaces. Finally, a significant drop in Ni ion release from 268±11 to 136±15 ppb was observed for NiTi surfaces after anodization. This work indicates that anodization of a NiTi alloy has a positive influence on the surface energy and surface morphology, which in turn improves bone cell-material interactions and reduces Ni ion release in vitro. Copyright © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

The first principle study of Ni{sub 2}ScGa and Ni{sub 2}TiGa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Özduran, Mustafa; Turgut, Kemal; Arikan, Nihat

2014-10-06

We computed the electronic structure, elastic moduli, vibrational properties, and Ni{sub 2}TiGa and Ni{sub 2}ScGa alloys in the cubic L2{sub 1} structure. The obtained equilibrium lattice constants of these alloys are in good agreement with available data. In cubic systems, there are three independent elastic constants, namely C{sub 11}, C{sub 12} and C{sub 44}. We calculated elastic constants in L2{sub 1} structure for Ni{sub 2}TiGa and Ni{sub 2}ScGa using the energy-strain method. The electronic band structure, total and partial density of states for these alloys were investigated within density functional theory using the plane-wave pseudopotential method implemented in Quantum-Espresso programmore » package. From band structure, total and projected density of states, we observed metallic characters of these compounds. The electronic calculation indicate that the predominant contributions of the density of states at Fermi level come from the Ni 3d states and Sc 3d states for Ni{sub 2}TiGa, Ni 3d states and Sc 3d states for Ni{sub 2}ScGa. The computed density of states at Fermi energy are 2.22 states/eV Cell for Ni{sub 2}TiGa, 0.76 states/eV Cell for Ni{sub 2}ScGa. The vibrational properties were obtained using a linear response in the framework at the density functional perturbation theory. For the alloys, the results show that the L2{sub 1} phase is unstable since the phonon calculations have imagine modes.« less

Magnetic and conventional shape memory behavior of Mn-Ni-Sn and Mn-Ni-Sn(Fe) alloys

NASA Astrophysics Data System (ADS)

Turabi, A. S.; Lázpita, P.; Sasmaz, M.; Karaca, H. E.; Chernenko, V. A.

2016-05-01

Magnetic and conventional shape memory properties of Mn49Ni42Sn9(at.%) and Mn49Ni39Sn9Fe3(at.%) polycrystalline alloys exhibiting martensitic transformation from ferromagnetic austenite into weakly magnetic martensite are characterized under compressive stress and magnetic field. Magnetization difference between transforming phases drastically increases, while transformation temperature decreases with the addition of Fe. Both Mn49Ni42Sn9 and Mn49Ni39Sn9Fe3 alloys show remarkable superelastic and shape memory properties with recoverable strain of 4% and 3.5% under compression at room temperature, respectively. These characteristics can be counted as extraordinary among the polycrystalline NiMn-based magnetic shape memory alloys. Critical stress for phase transformation was increased by 34 MPa in Mn49Ni39Sn9Fe3 and 21 MPa in Mn49Ni42Sn9 at 9 T, which can be qualitatively understood in terms of thermodynamic Clausius-Clapeyron relationships and in the framework of the suggested physical concept of a volume magnetostress.

Process development for Ni-Cr-ThO2 and Ni-Cr-Al-ThO2 sheet

NASA Technical Reports Server (NTRS)

Cook, R. C.; Norris, L. F.

1973-01-01

A process was developed for the production of thin gauge Ni-Cr-ThO2 sheet. The process was based on the elevated temperature deposition of chromium onto a wrought Ni-2%ThO2 sheet and subsequent high temperature diffusion heat treatments to minimize chromium concentration gradients within the sheet. The mechanical properties of the alloy were found to be critically dependent on those of the Ni-2%ThO2 sheet. A similar process for the production of a Ni-Cr-Al-ThO2 alloy having improved oxidation resistance was investigated but the non-reproducible deposition of aluminum from duplex Cr/Al packs precluded successful scale-up. The mechanical properties of the Ni-Cr-Al-ThO2 alloys were generally equivalent to the best Ni-Cr-ThO2 alloy produced in the programme.

TaiWan Ionospheric Model (TWIM) prediction based on time series autoregressive analysis

NASA Astrophysics Data System (ADS)

Tsai, L. C.; Macalalad, Ernest P.; Liu, C. H.

2014-10-01

As described in a previous paper, a three-dimensional ionospheric electron density (Ne) model has been constructed from vertical Ne profiles retrieved from the FormoSat3/Constellation Observing System for Meteorology, Ionosphere, and Climate GPS radio occultation measurements and worldwide ionosonde foF2 and foE data and named the TaiWan Ionospheric Model (TWIM). The TWIM exhibits vertically fitted α-Chapman-type layers with distinct F2, F1, E, and D layers, and surface spherical harmonic approaches for the fitted layer parameters including peak density, peak density height, and scale height. To improve the TWIM into a real-time model, we have developed a time series autoregressive model to forecast short-term TWIM coefficients. The time series of TWIM coefficients are considered as realizations of stationary stochastic processes within a processing window of 30 days. These autocorrelation coefficients are used to derive the autoregressive parameters and then forecast the TWIM coefficients, based on the least squares method and Lagrange multiplier technique. The forecast root-mean-square relative TWIM coefficient errors are generally <30% for 1 day predictions. The forecast TWIM values of foE and foF2 values are also compared and evaluated using worldwide ionosonde data.

The efficacy of Tai Chi Chuan in older adults: a systematic review.

PubMed

Verhagen, Arianne P; Immink, Monique; van der Meulen, Annemieke; Bierma-Zeinstra, Sita M A

2004-02-01

The purpose of this study was to assess the effect of Tai Chi Chuan (TCC) on fall prevention, balance and cardiorespiratory functions in the elderly. A systematic review was carried out according to the Cochrane standards. A computerized literature search was carried out. Studies were selected when they had an experimental design; the age of the study population was >50; one of the interventions was a form of TCC; and when falls, balance or cardiorespiratory functions were used as an outcome measure. A total of seven studies were included, with in total 505 participants, of whom all but 27 were healthy seniors, age between 53 and 96 years. In most studies, the intervention of TCC is a modified Yang style, varying from 10 to 24 forms. The intensity of TCC varies from 1 h weekly for 10 weeks to 1 h every morning for 1 year. One study used falls as outcome measure and reported a beneficial effect of 47% in the TCC group. All studies mention a beneficial effect of TCC, but in most studies this conclusion was based on a pre-post analysis. There is limited evidence that TCC is effective in reducing falls and blood pressure in the elderly.

The asymmetric response of Yangtze river basin summer rainfall to El Niño/La Niña

NASA Astrophysics Data System (ADS)

Hardiman, Steven C.; Dunstone, Nick J.; Scaife, Adam A.; Bett, Philip E.; Li, Chaofan; Lu, Bo; Ren, Hong-Li; Smith, Doug M.; Stephan, Claudia C.

2018-02-01

The Yangtze river basin, in South East China, experiences anomalously high precipitation in summers following El Niño. This can lead to extensive flooding and loss of life. However, the response following La Niña has not been well documented. In this study, the response of Yangtze summer rainfall to El Niño/La Niña is found to be asymmetric, with no significant response following La Niña. The nature of this asymmetric response is found to be in good agreement with that simulated by the Met Office seasonal forecast system. Yangtze summer rainfall correlates positively with spring sea surface temperatures in the Indian Ocean and northwest Pacific. Indian Ocean sea surface temperatures are found to respond linearly to El Niño/La Niña, and to have a linear impact on Yangtze summer rainfall. However, northwest Pacific sea surface temperatures respond much more strongly following El Niño and, further, correlate more strongly with positive rainfall years. It is concluded that, whilst delayed Indian Ocean signals may influence summer Yangtze rainfall, it is likely that they do not lead to the asymmetric nature of the rainfall response to El Niño/La Niña.

Ni3Si2 nanowires grown in situ on Ni foam for high-performance supercapacitors

NASA Astrophysics Data System (ADS)

Jiang, Yizhe; Li, Zhihui; Li, Beibei; Zhang, Jinying; Niu, Chunming

2016-07-01

Ni3Si2 nanowires and nanoawls have grown in situ on the surface of Ni foams by a controlled low pressure chemical vapor deposition process. Structural characterization shows that the individual Ni3Si2 nanowire is single crystal covered with a thin layer (1-2 nm) of SiO2 with a diameter of ∼20-30 nm and length of ten's micrometers. Individual nanoawl with a circular cone shape is polycrystalline. Both Ni3Si2 nanowire and nanoawl samples are evaluated as potential electrode materials for supercapacitors. The nanowire electrode delivers a very high specific capacitance and excellent rate capability. A specific capacitance of 760 F g-1 is measured at current density of 0.5 A g-1, which decreases to 518 F g-1 when the current density increases to 10 A g-1. The capacitance is dominated by pseudocapacitance with a mechanism similar to that of NiO or Ni(OH)2 widely studied in the literature. An asymmetric supercapacitor fabricated by pairing Ni3Si2 nanowire electrode with an activated carbon electrode exhibits energy densities of 17.5 Wh kg-1 and 8.8 Wh kg-1 at power densites of 301 W kg-1 and 3000 W kg-1.

Fluorescence x-ray absorption fine structure studies of Fe-Ni-S and Fe-Ni-Si melts to 1600 K

NASA Astrophysics Data System (ADS)

Manghnani, M. H.; Hong, X.; Balogh, J.; Amulele, G.; Sekar, M.; Newville, M.

2008-04-01

We report NiK -edge fluorescence x-ray absorption fine structure spectra (XAFS) for Fe0.75Ni0.05S0.20 and Fe0.75Ni0.05Si0.20 ternary alloys from room temperature up to 1600 K. A high-temperature furnace designed for these studies incorporates two x-ray transparent windows and enables both a vertical orientation of the molten sample and a wide opening angle, so that XAFS can be measured in the fluorescence mode with a detector at 90° with respect to the incident x-ray beam. An analysis of the Ni XAFS data for these two alloys indicates different local structural environments for Ni in Fe0.75Ni0.05S0.20 and Fe0.75Ni0.05Si0.20 melts, with more Ni-Si coordination than Ni-S coordination persisting from room temperature through melting. These results suggest that light elements such as S and Si may impact the structural and chemical properties of Fe-Ni alloys with a composition similar to the earth’s core.

Thermal modeling of NiH2 batteries

NASA Technical Reports Server (NTRS)

Ponthus, Agnes-Marie; Alexandre, Alain

1994-01-01

The following are discussed: NiH2 battery mission and environment; NiH2 cell heat dissipation; Nodal software; model development general philosophy; NiH2 battery model development; and NiH2 experimental developments.

Who is El Niño?

NASA Astrophysics Data System (ADS)

Philander, S. George

It is a curious story, about a phenomenon we first welcomed as a blessing but now view with dismay, if not horror [Philander, 1998]. We named it El Niño for the child Jesus, provided it with relatives—La Niña and ENSO—and are devoting innumerable studies to the description and idealization of this family. These scriptures provide such a broad spectrum of historical, cultural, and scientific perspectives that there is now confusion about the identity of El Niño. Trenberth [1997] summarizes the situation as follows.The atmospheric component tied to El Niño is termed the “Southern Oscillation.” Scientists often call the phenomenon where the atmosphere and ocean collaborate ENSO, short for El Niño-Southern Oscillation. El Niño then corresponds to the warm phase of ENSO. The opposite “La Niña” (“the girl” in Spanish) phase consists of a basinwide cooling of the tropical Pacific and thus the cold phase of ENSO. However, for the public, the term for the whole phenomenon is “El Niño.”

Synthesis and catalytic activity of electrospun NiO/NiCo2O4 nanotubes for CO and acetaldehyde oxidation

NASA Astrophysics Data System (ADS)

Kim, Il Hee; Lee, Hyerim; Yu, Areum; Jeong, Jae Hwan; Lee, Youngmi; Kim, Myung Hwa; Lee, Chongmok; Dok Kim, Young

2018-04-01

NiO/NiCo2O4 nanotubes with a diameter of approximately 100 nm are synthesized using Ni and Co precursors via electro-spinning and subsequent calcination processes. The tubular structure is confirmed via transmission electron microscopy imaging, whereas the structures and elemental compositions of the nanotubes are determined using x-ray diffraction, energy dispersive x-ray spectroscopy, and x-ray photoelectron spectroscopy. N2 adsorption isotherm data reveal that the surface of the nanotubes consists of micropores, thereby resulting in a significantly higher surface area (˜20 m2 g-1) than expected for a flat-surface structure (<15 m2 g-1). Herein, we present a study of the catalytic activity of our novel NiO/NiCo2O4 nanotubes for CO and acetaldehyde oxidation. The catalytic activity of NiO/NiCo2O4 is superior to Pt below 100 °C for CO oxidation. For acetaldehyde oxidation, the total oxidation activity of NiO/NiCo2O4 for acetaldehyde is comparable with that of Pt. Coexistence of many under-coordinated Co and Ni active sites in our structure is suggested be related to the high catalytic activity. It is suggested that our novel NiO/NiCo2O4 tubular structures with surface microporosity can be of interest for a variety of applications, including the catalytic oxidation of harmful gases.

Synthesis and catalytic activity of electrospun NiO/NiCo2O4 nanotubes for CO and acetaldehyde oxidation.

PubMed

Kim, Il Hee; Lee, Hyerim; Yu, Areum; Jeong, Jae Hwan; Lee, Youngmi; Kim, Myung Hwa; Lee, Chongmok; Kim, Young Dok

2018-04-27

NiO/NiCo 2 O 4 nanotubes with a diameter of approximately 100 nm are synthesized using Ni and Co precursors via electro-spinning and subsequent calcination processes. The tubular structure is confirmed via transmission electron microscopy imaging, whereas the structures and elemental compositions of the nanotubes are determined using x-ray diffraction, energy dispersive x-ray spectroscopy, and x-ray photoelectron spectroscopy. N 2 adsorption isotherm data reveal that the surface of the nanotubes consists of micropores, thereby resulting in a significantly higher surface area (∼20 m 2 g -1 ) than expected for a flat-surface structure (<15 m 2 g -1 ). Herein, we present a study of the catalytic activity of our novel NiO/NiCo 2 O 4 nanotubes for CO and acetaldehyde oxidation. The catalytic activity of NiO/NiCo 2 O 4 is superior to Pt below 100 °C for CO oxidation. For acetaldehyde oxidation, the total oxidation activity of NiO/NiCo 2 O 4 for acetaldehyde is comparable with that of Pt. Coexistence of many under-coordinated Co and Ni active sites in our structure is suggested be related to the high catalytic activity. It is suggested that our novel NiO/NiCo 2 O 4 tubular structures with surface microporosity can be of interest for a variety of applications, including the catalytic oxidation of harmful gases.

The influence of Si in Ni on the interface modification and the band alignment between Ni and alumina

NASA Astrophysics Data System (ADS)

Yoshitake, Michiko; Nemšák, Slavomír; Skála, Tomáš; Tsud, Nataliya; Matolín, Vladimír; Prince, Kevin C.

2018-06-01

The influence of a small amount of Si in a Ni single crystal on the interface formation between aluminum oxide and Ni has been investigated. The interface was formed by in-situ growth of the oxide by simultaneous supply of Al and oxygen onto Ni(1 1 1) in an ultrahigh vacuum chamber equipped with XPS apparatus. The oxide growth and the interface formation were compared between Si-containing Ni(1 1 1) and pure Ni(1 1 1). It was revealed that Si segregated on the surface of Ni and oxidized, forming an epitaxial thin alumino-silicate film. Valence band spectra demonstrated that the band offset between the oxide and Ni (energy level difference between the valence band top and the Fermi level) is different due to the oxidized Si segregation at the interface.

Metal-semiconductor interfacial reactions - Ni/Si system

NASA Technical Reports Server (NTRS)

Cheung, N. W.; Grunthaner, P. J.; Grunthaner, F. J.; Mayer, J. W.; Ullrich, B. M.

1981-01-01

X-ray photoelectron spectroscopy and channeling measurements with MeV He-4(+) ions have been used to probe the structure of the interface in the Ni/Si system. It is found that reactions occur where Ni is deposited on Si at 10 to the -10th torr: Si atoms are displaced from lattice sites, the Ni atoms are in an Si-rich environment, and the Ni/Si interface is graded in composition. Composition gradients are present at both interfaces in the Si/Ni2/Si/Ni system. For the Ni-Si system, cooling the substrate to 100 K slows down the reaction rate. The temperature dependence of the interfacial reactivity indicates the kinetic nature of metal-semiconductor interfaces.

Impact of La Niña and La Niña Modoki on Indonesia rainfall variability

NASA Astrophysics Data System (ADS)

Hidayat, R.; Juniarti, MD; Ma’rufah, U.

2018-05-01

La Niña events are indicated by cooling SST in central and eastern equatorial Pacific. While La Niña Modoki occurrences are indicated by cooling SST in central Pacific and warming SST in western and eastern equatorial Pacific. These two events are influencing rainfall variability in several regions including Indonesia. The objective of this study is to analyse the impact of La Niña and La Niña Modoki on Indonesian rainfall variability. We found the Nino 3.4 index is highly correlated (r = -0.95) with Indonesian rainfall. Positive rainfall anomalies up to 200 mm/month occurred mostly in Indonesian region during La Niña events, but in DJF several areas of Sumatera, Kalimantan and eastern Indonesia tend to have negative rainfall. During La Niña Modoki events, positive rainfall anomaly (up to 50 mm/month) occurred in Sumatera Island, Kalimantan, Java and eastern Indonesia in DJF and up to 175 mm/month occurred only in Java Island in MAM season. La Niña events have strong cooling SST in central and eastern equatorial Pacific (-1.5°C) in DJF. While La Niña Modoki events warming SST occurred in western and eastern equatorial Pacific (0.75°C) and cooling SST in central Pacific (- 0.75°C) in DJF and MAM. Walker circulation in La Niña Modoki events (on DJF and MAM) showed strong convergence in eastern Pacific, and weak convergence in western Pacific (Indonesia).