Whole body immersion and hydromineral homeostasis: effect of water temperature.

Science.gov (United States)

Jimenez, Chantal; Regnard, Jacques; Robinet, Claude; Mourot, Laurent; Gomez-Merino, Danielle; Chennaoui, Mounir; Jammes, Yves; Dumoulin, Gilles; Desruelle, Anne-Virginie; Melin, Bruno

2010-01-01

This experiment was designed to assess the effects of prolonged whole body immersion (WBI) in thermoneutral and cold conditions on plasma volume and hydromineral homeostasis.10 navy "combat swimmers" performed three static 6-h immersions at 34 degrees C (T34), 18 degrees C (T18) and 10 degrees C (T10). Rectal temperature, plasma volume (PV) changes, plasma proteins, plasma and urine ions, plasma osmolality, renin, aldosterone and antidiuretic hormone (ADH) were measured. Results show that compared to pre-immersion levels, PV decreased throughout WBI sessions, the changes being markedly accentuated in cold conditions. At the end of WBI, maximal PV variations were -6.9% at T34, -14.3% at T18, and -16.3% at T10. Plasma osmolality did not change during and after T34 immersion, while hyperosmolality was present at the end of T18 immersion and began after only 1 h of T10 immersion. In the three temperature conditions, significant losses of water (1.6-1.7 l) and salt (6-8 g) occurred and were associated with similar increases in osmolar and free water clearances. Furthermore, T18 and T10 immersions increased the glomerular filtration rate. There was little or no change in plasma renin and ADH, while the plasma level of aldosterone decreased equally in the three temperature conditions. In conclusion, our data indicate that cold water hastened PV changes induced by immersion, and increased the glomerular filtration rate, causing larger accumulated water losses. The iso-osmotic hypovolemia may impede the resumption of baseline fluid balance. Results are very similar to those repeatedly described by various authors during head-out water immersion.

Using heart rate to prescribe physical exercise during head-out water immersion.

Science.gov (United States)

Kruel, Luiz F M; Peyré-Tartaruga, Leonardo A; Coertjens, Marcelo; Dias, Adriana B C; Da Silva, Rafael C; Rangel, Antônio C B

2014-01-01

The purpose of this study was to compare and correlate the effect of age group, sex, depth of water immersion, and the heart rate (HR) assessed out of the water on the HR behavior in individuals subjected to head-out water immersion. A total of 395 healthy individuals of both sexes, aged between 07 and 75 years, underwent vertical head-out water immersion. Heart rate was assessed out of the water in the supine and orthostatic (OHR) positions and at immersion depths corresponding to the ankle, knee, hip, umbilicus, xiphoid process, acromion, neck, and also the neck with the arms out of the water. The formula (ΔHR = OHR - HR immersion depth) was used to calculate the reduction in HR at each immersion depth. No age-based or sex-based differences in HR were found. The greater the depth of the water, the greater was the decrease in HR (p water-based exercise intensity performed during vertical immersion: OHR should be measured before the individual entering the aquatic environment; ΔHR should be measured according to the depth at which exercise is to be performed, and we suggest an adaptation to Karvonen's HRmax prediction formula (predicted HRmax: 220 - age - ΔHR) to prescribe and control the intensity of the exercise performed during vertical immersion.

Water-immersion type ship reactor

International Nuclear Information System (INIS)

Okada, Hiroki; Yamamura, Toshio.

1996-01-01

In a water immersion-type ship reactor in which a water-tight wall is formed around a pressure vessel by way of an air permeable heat insulation layer and immersing the wall under water in a reactor container, a pressure equalizing means equipped with a back flow check valve and introducing a gas in a gas phase portion above the water level of the container into a water tight wall and a relief valve for releasing the gas in the water tight wall to the reactor container are disposed on the water tight wall. When the pressure in the water tight wall exceeds the pressure in the container, the gas in the water tight wall is released from the relief valve to the reactor container. On the contrary, when the pressure in the container exceeds the pressure in the water tight wall, the gas in the gas phase portion is flown from the pressure equalizing means equipped with a back flow check valve to the inside of the water tight wall. Thus, a differential pressure between both of them is kept around 0kg/cm 2 . A large differential pressure is not exerted on the water tight wall thereby capable of preventing rupture of them to improve reliability, as well as the thickness of the plate can be decreased thereby enabling to moderate the design for the pressure resistance and reduce the weight. (N.H.)

Heat Acclimation and Water-Immersion Deconditioning: Responses to Exercise

Science.gov (United States)

Shvartz, E.; Bhattacharya, A.; Sperinde, S. J.; Brock, P. J.; Sciaraffa, D.; Haines, R. F.; Greenleaf, J. E.

1977-01-01

Simulated subgravity conditions, such as bed rest and water immersion, cause a decrease in a acceleration tolerance (3, 4), tilt tolerance (3, 9, 10), work capacity (5, 7), and plasma volume (1, 8-10). Moderate exercise training performed during bed rest (4) and prior to water immersion (5) provides some protection against the adverse effects of deconditioning, but the relationship between exercise and changes due to deconditioning remains unclear. Heat acclimation increases plasma and interstitial volumes, total body water, stroke volume (11), and tilt tolerance (6) and may, therefore, be a more efficient method of ameliorating deconditioning than physical training alone. The present study was undertaken to determine the effects of heat acclimation and moderate physical training, performed in cool conditions, on water-immersion deconditioning.

Immersion in water in labour and birth

Directory of Open Access Journals (Sweden)

Elizabeth R. Cluett

Full Text Available BACKGROUND: Enthusiasts suggest that labouring in water and waterbirth increase maternal relaxation, reduce analgesia requirements and promote a midwifery model of care. Critics cite the risk of neonatal water inhalation and maternal/neonatal infection. OBJECTIVES: To assess the evidence from randomised controlled trials about immersion in water during labour and waterbirth on maternal, fetal, neonatal and caregiver outcomes. METHODS: Search methods: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (30 June 2011 and reference lists of retrieved studies. Selection criteria: Randomised controlled trials comparing immersion in any bath tub/pool with no immersion, or other non-pharmacological forms of pain management during labour and/or birth, in women during labour who were considered to be at low risk of complications, as defined by the researchers. Data collection and analysis: We assessed trial eligibility and quality and extracted data independently. One review author entered data and the other checked for accuracy. MAIN RESULTS: This review includes 12 trials (3,243 women: 8 related to just the first stage of labour: one to early versus late immersion in the first stage of labour; two to the first and second stages; and another to the second stage only. We identified no trials evaluating different baths/pools, or the management of third stage of labour. Results for the first stage of labour showed there was a significant reduction in the epidural/spinal/paracervical analgesia/anaesthesia rate amongst women allocated to water immersion compared to controls (478/1,254 versus 529/1,245; risk ratio (RR 0.90; 95% confidence interval (CI 0.82 to 0.99, six trials. There was also a reduction in duration of the first stage of labour (mean difference -32.4 minutes; 95% CI -58.7 to -6.13. There was no difference in assisted vaginal deliveries (RR 0.86; 95% CI 0.71 to 1.05, seven trials, caesarean sections (RR 1.21; 95% CI 0

Significant improvement of optical traps by tuning standard water immersion objectives

International Nuclear Information System (INIS)

Reihani, S Nader S; Mir, Shahid A; Richardson, Andrew C; Oddershede, Lene B

2011-01-01

Focused infrared lasers are widely used for micromanipulation and visualization of biological specimens. An inherent practical problem is that off-the-shelf commercial microscope objectives are designed for use with visible and not infrared wavelengths. Less aberration is introduced by water immersion objectives than by oil immersion ones, however, even water immersion objectives induce significant aberration. We present a simple method to reduce the spherical aberration induced by water immersion objectives, namely by tuning the correction collar of the objective to a value that is ∼ 10% lower than the physical thickness of the coverslip. This results in marked improvements in optical trapping strengths of up to 100% laterally and 600% axially from a standard microscope objective designed for use in the visible range. The results are generally valid for any water immersion objective with any numerical aperture

Impact of continuous positive airway pressure on the pulmonary changes promoted by immersion in water

Directory of Open Access Journals (Sweden)

Danize Aparecida Rizzetti

Full Text Available ABSTRACT Objective: To determine whether different levels of CPAP improve the lung volumes and capacities of healthy subjects immersed in water. Methods: This was a randomized clinical trial, conducted between April and June of 2016, involving healthy female volunteers who were using oral contraceptives. Three 20-min immersion protocols were applied: control (no CPAP; CPAP5 (CPAP at 5 cmH2O; and CPAP10 (CPAP at 10 cmH2O. We evaluated HR, SpO2, FVC, FEV1, the FEV1/FVC ratio, peak expiratory flow rate (PEFR, and FEF25-75% at three time points: pre-immersion; 10 min after immersion; and 10 min after the end of each protocol. Results: We evaluated 13 healthy volunteers. The CPAP10 protocol reversed the restrictive pattern of lung function induced by immersion in water, maintaining pulmonary volumes and capacities for a longer period than did the CPAP5 protocol. Conclusions: When the hemodynamic change causing a persistent lung disorder, only the application of higher positive pressures is effective in maintaining long-term improvements in the pulmonary profile.

Impact of continuous positive airway pressure on the pulmonary changes promoted by immersion in water.

Science.gov (United States)

Rizzetti, Danize Aparecida; Quadros, Janayna Rodembuch Borba; Ribeiro, Bruna Esmerio; Callegaro, Letícia; Veppo, Aline Arebalo; Wiggers, Giulia Alessandra; Peçanha, Franck Maciel

2017-01-01

To determine whether different levels of CPAP improve the lung volumes and capacities of healthy subjects immersed in water. This was a randomized clinical trial, conducted between April and June of 2016, involving healthy female volunteers who were using oral contraceptives. Three 20-min immersion protocols were applied: control (no CPAP); CPAP5 (CPAP at 5 cmH2O); and CPAP10 (CPAP at 10 cmH2O). We evaluated HR, SpO2, FVC, FEV1, the FEV1/FVC ratio, peak expiratory flow rate (PEFR), and FEF25-75%) at three time points: pre-immersion; 10 min after immersion; and 10 min after the end of each protocol. We evaluated 13 healthy volunteers. The CPAP10 protocol reversed the restrictive pattern of lung function induced by immersion in water, maintaining pulmonary volumes and capacities for a longer period than did the CPAP5 protocol. When the hemodynamic change causing a persistent lung disorder, only the application of higher positive pressures is effective in maintaining long-term improvements in the pulmonary profile.

Long-term solute diffusion in a granite block immersed in sea water

International Nuclear Information System (INIS)

Jefferies, N.L.

1988-01-01

Solute diffusion profiles for Cl - , Br - , F - and SO 4 -- have been measured in a granite block which was immersed in the sea at Falmouth, Cornwall, for 30 years. Leachable concentrations of Cl - and Br - were found to be higher in the block than in quarry samples of granite, which demonstrates that solutes from the sea water have diffused into the block. The Cl - and Br - profiles within the block were flat, implying that equilibrium has been reached between the seawater and granite porewater. The apparent diffusion coefficient and the solute accessible porosity have been estimated from these profiles, and these were used to calculate the intrinsic diffusion coefficient which was then compared with previously obtained laboratory data. Concentration profiles for F - and S0 4 -- indicate that these elements have high concentrations at the margins of the block (to depths of up to 15 cm) and are in the process of diffusing outwards into the surrounding seawater. The initially high porewater concentrations of F - and SO 4 -- in the block are believed to result from weathering of the granite prior to its immersion in the sea, due to the breakdown of primary minerals such as pyrite and the micas. F - and SO 4 -- sorptivity has been estimated from an analysis of the porewater concentration profiles. This preliminary experiment has demonstrated the potential for the measurement of solute migration in granite, as a result of the rock having been immersed in seawater. This work is part of the CEC project MIRAGE (radionuclide migration in the geosphere)- Second phase (1985-89) Research area 'Natural analogues'

Cold-water immersion (cryotherapy for preventing and treating muscle soreness after exercise

Directory of Open Access Journals (Sweden)

Chris Bleakley

Full Text Available BACKGROUND: Many strategies are in use with the intention of preventing or minimizing delayed onset muscle soreness and fatigue after exercise. Cold-water immersion, in water temperatures of less than 15 °C, is currently one of the most popular interventional strategies used after exercise. OBJECTIVES: To determine the effects of cold-water immersion in the management of muscle soreness after exercise. SEARCH METHODS: In February 2010, we searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register, the Cochrane Central Register of Controlled Trials (The Cochrane Library (2010, Issue 1, Medline, Embase, Cumulative Index to Nursing and Allied Health (CINAHL, British Nursing Index and archive (BNI, and the Physiotherapy Evidence Database (PEDro. We also searched the reference lists of articles, handsearched journals and conference proceedings and contacted experts. In November 2011, we updated the searches of Central (2011, Issue 4, Medline (up to November Week 3 2011, Embase (to 2011 Week 46 and CINAHL (to 28 November 2011 to check for more recent publications. SELECTION CRITERIA: Randomized and quasi-randomized trials comparing the effect of using cold-water immersion after exercise with: passive intervention (rest/no intervention, contrast immersion, warm-water immersion, active recovery, compression, or a different duration/dosage of cold-water immersion. Primary outcomes were pain (muscle soreness or tenderness (pain on palpation, and subjective recovery (return to previous activities without signs or symptoms. DATA COLLECTION AND ANALYSIS: Three authors independently evaluated study quality and extracted data. Some of the data were obtained following author correspondence or extracted from graphs in the trial reports. Where possible, data were pooled using the fixed-effect model. MAIN RESULTS: Seventeen small trials were included, involving a total of 366 participants. Study quality was low. The temperature, duration and

Maintenance of immersion ultrasonic testing on the water tube boiler

International Nuclear Information System (INIS)

Ishiyama, Toru; Kawasaki, Ichio; Miura, Hirohito

2014-01-01

There are 4-boiler in nuclear fuel cycle engineering laboratories (NCL). These boilers have been operated in the long term over 20 years. One of them, the leakage of boiler water was found at one of the generating tubes, and 2 adjoining generating tubes were corroded in Dec, 2011. These generating tubes were investigated by immersion ultrasonic testing (UT) for measure thickness of the tube. As a result, thinner tube was found in a part of a bend and near the water drum. These parts are covered with sulfide deposit, it seems that the generating tubes were corroded by sulfide. (author)

Reduced cerebral perfusion on sudden immersion in ice water: a possible cause of drowning

DEFF Research Database (Denmark)

Mantoni, Teit; Belhage, Bo; Pedersen, Lars M

2007-01-01

INTRODUCTION: Near-drowning incidents and drowning deaths after accidental immersion in open waters have been linked to cold shock response. It consists of inspiratory gasps, hyperventilation, tachycardia, and hypertension in the first 2-3 min of cold-water immersion. This study explored the imme......INTRODUCTION: Near-drowning incidents and drowning deaths after accidental immersion in open waters have been linked to cold shock response. It consists of inspiratory gasps, hyperventilation, tachycardia, and hypertension in the first 2-3 min of cold-water immersion. This study explored...... cerebral artery (MCA) was measured together with ventilatory parameters and heart rate before, during, and after immersion. RESULTS: Within seconds after immersion in ice water, heart rate increased from 74 +/- 16 to 107 +/- 18 bpm (mean +/- SD; p elevation...

Mechanism study of the electrical performance change of silicon concentrator solar cells immersed in de-ionized water

International Nuclear Information System (INIS)

Han Xinyue; Wang Yiping; Zhu Li; Xiang Haijun; Zhang Hui

2012-01-01

Highlights: ► Factors for performance degradation of silicon CPV cells in DI water were investigated. ► Long term immersion results showed no significant degradation on bare silicon CPV cell in 65° C DI water. ► Isc, not Voc of tabbed cells decreased with exposure time, notably under sunlight. ► The occurrence of galvanic corrosion on tabbed CPV cells has been confirmed. ► Performance recovery of tabbed cells after cleaning indicated that the cells are not damaged after long-time immersion. - Abstract: Direct de-ionized (DI) water immersion cooling has been verified to be an effective method of managing the operating temperature of silicon solar cells under concentration. However, the stable electrical performance is difficult to be achieved. Possible factors from bare cell self, materials for tabbing cells were investigated in this study for understanding the degradation mechanism. Long term immersion results showed that no significant degradation on bare cells operated in DI water at 65 °C. When cells were tabbed using lead-based solder and flux, the short circuit current (I sc ) of cells decreased with exposure time, notably under sunlight, but it was not observed for cell open circuit voltage (V oc ). The epoxy tabbed cells test also demonstrated that the tabbed cells without lead-based solder and flux involved were also found drop in I sc , but with slower rate. The presence of lead and tin black oxides on the lead based-soldered tabbed cells and red deposition on the epoxy tabbed cells confirmed the occurrence of galvanic corrosion. However, particular cleaning recovers the I–V towards its initial values for the former tabbed cells, and partial recovery for the latter tabbed cells, which indicates that the cells are not damaged after long-time DI water immersion.

Voluntary respiratory control and cerebral blood flow velocity upon ice-water immersion

DEFF Research Database (Denmark)

Mantoni, Teit; Rasmussen, Jakob Højlund; Belhage, Bo

2008-01-01

INTRODUCTION: In non-habituated subjects, cold-shock response to cold-water immersion causes rapid reduction in cerebral blood flow velocity (approximately 50%) due to hyperventilation, increasing risk of syncope, aspiration, and drowning. Adaptation to the response is possible, but requires...... velocity (CBFV) was measured together with ventilatory parameters and heart rate before, during, and after immersion. RESULTS: Within seconds after immersion in ice-water, heart rate increased significantly from 95 +/- 8 to 126 +/- 7 bpm (mean +/- SEM). Immersion was associated with an elevation...

Lipid-induced thermogenesis is up-regulated by the first cold-water immersions in juvenile penguins.

Science.gov (United States)

Teulier, Loïc; Rey, Benjamin; Tornos, Jérémy; Le Coadic, Marion; Monternier, Pierre-Axel; Bourguignon, Aurore; Dolmazon, Virginie; Romestaing, Caroline; Rouanet, Jean-Louis; Duchamp, Claude; Roussel, Damien

2016-07-01

The passage from shore to marine life is a critical step in the development of juvenile penguins and is characterized by a fuel selection towards lipid oxidation concomitant to an enhancement of lipid-induced thermogenesis. However, mechanisms of such thermogenic improvement at fledging remain undefined. We used two different groups of pre-fledging king penguins (Aptenodytes patagonicus) to investigate the specific contribution of cold exposure during water immersion to lipid metabolism. Terrestrial penguins that had never been immersed in cold water were compared with experimentally cold-water immersed juveniles. Experimentally immersed penguins underwent ten successive immersions at approximately 9-10 °C for 5 h over 3 weeks. We evaluated adaptive thermogenesis by measuring body temperature, metabolic rate and shivering activity in fully immersed penguins exposed to water temperatures ranging from 12 to 29 °C. Both never-immersed and experimentally immersed penguins were able to maintain their homeothermy in cold water, exhibiting similar thermogenic activity. In vivo, perfusion of lipid emulsion at thermoneutrality induced a twofold larger calorigenic response in experimentally immersed than in never-immersed birds. In vitro, the respiratory rates and the oxidative phosphorylation efficiency of isolated muscle mitochondria were not improved with cold-water immersions. The present study shows that acclimation to cold water only partially reproduced the fuel selection towards lipid oxidation that characterizes penguin acclimatization to marine life.

Influence of water immersion, water gymnastics and swimming on cardiac output in patients with heart failure.

Science.gov (United States)

Schmid, Jean-Paul; Noveanu, Markus; Morger, Cyrill; Gaillet, Raymond; Capoferri, Mauro; Anderegg, Matthias; Saner, Hugo

2007-06-01

Whole-body water immersion leads to a significant shift of blood from the periphery to the intrathoracic circulation, followed by an increase in central venous pressure and heart volume. In patients with severely reduced left ventricular function, this hydrostatically induced volume shift might overstrain the cardiovascular adaptive mechanisms and lead to cardiac decompensation. To assess the haemodynamic response to water immersion, gymnastics and swimming in patients with chronic heart failure (CHF). 10 patients with compensated CHF (62.9 (6.3) years, ejection fraction 31.5% (4.1%), peak oxygen consumption (Vo(2)) 19.4 (2.8) ml/kg/min), 10 patients with coronary artery disease (CAD) but preserved left ventricular function (57.2 (5.6) years, ejection fraction 63.9% (5.5%), peak Vo(2) 28 (6.3) ml/kg/min), and 10 healthy controls (32.8 (7.2) years, peak Vo(2) 45.6 (6) ml/kg/min) were examined. Haemodynamic response to thermoneutral (32 degrees C) water immersion and exercise was measured using a non-invasive foreign gas rebreathing method during stepwise water immersion, water gymnastics and swimming. Water immersion up to the chest increased cardiac index by 19% in controls, by 21% in patients with CAD and by 16% in patients with CHF. Although some patients with CHF showed a decrease of stroke volume during immersion, all subjects were able to increase cardiac index (by 87% in healthy subjects, by 77% in patients with CAD and by 53% in patients with CHF). Vo(2) during swimming was 9.7 (3.3) ml/kg/min in patients with CHF, 12.4 (3.5) ml/kg/min in patients with CAD and 13.9 (4) ml/kg/min in controls. Patients with severely reduced left ventricular function but stable clinical conditions and a minimal peak Vo(2) of at least 15 ml/kg/min during a symptom-limited exercise stress test tolerate water immersion and swimming in thermoneutral water well. Although cardiac index and Vo(2) are lower than in patients with CAD with preserved left ventricular function and controls

Prolonged whole-body cold water immersion: fluid and ion shifts.

Science.gov (United States)

Deuster, P A; Smith, D J; Smoak, B L; Montgomery, L C; Singh, A; Doubt, T J

1989-01-01

To characterize fluid and ion shifts during prolonged whole-body immersion, 16 divers wearing dry suits completed four whole-body immersions in 5 degrees C water during each of two 5-day air saturation dives at 6.1 msw. One immersion was conducted at 1000 (AM) and one at 2200 (PM) so that diurnal variations could be evaluated. Fifty-four hours separated the immersions, which lasted up to 6 h; 9 days separated each air saturation dive. Blood was collected before and after immersion; urine was collected for 12 h before, during, and after immersion for a total of 24 h. Plasma volume decreased significantly and to the same extent (approximately 17%) during both AM and PM immersions. Urine flow increased by 236.1 +/- 38.7 and 296.3 +/- 52.0%, urinary excretion of Na increased by 290.4 +/- 89.0 and 329.5 +/- 77.0%, K by 245.0 +/- 73.4 and 215.5 +/- 44.6%, Ca by 211.0 +/- 31.4 and 241.1 +/- 50.4%, Mg by 201.4 +/- 45.9 and 165.3 +/- 287%, and Zn by 427.8 +/- 93.7 and 301.9 +/- 75.4% during AM and PM immersions, respectively, compared with preimmersion. Urine flow and K excretion were significantly higher during the AM than PM. In summary, when subjects are immersed in cold water for prolonged periods, combined with a slow rate of body cooling afforded by thermal protection and enforced intermittent exercise, there is diuresis, decreased plasma volume, and increased excretions of Na, K, Ca, Mg, and Zn.

Growth hormone and prolactin responses during partial and whole body warm-water immersions.

Science.gov (United States)

Koska, J; Rovensky, J; Zimanova, T; Vigas, M

2003-05-01

To elucidate the role of core and skin thermoreceptors in the release of growth hormone (GH) and prolactin (PRL), a sequence of two experiments using whole-body (head-out) and partial (one forearm) hot water immersions was performed. Experiment 1: Nine healthy men were exposed to head-out and partial water immersions (25 min, 38-39 degrees C). Head-out immersion increased the core temperature (38.0 +/- 0.1 vs. 36.7 +/- 0.1 degrees C, P immersion the core temperature was slightly elevated (36.8 +/- 0.1 vs. 36.6 +/- 0.1, P immersed one forearm once in 39 degrees C and once in 38 degrees C water. The measurements were performed in 5-min intervals. The GH concentration increased gradually from the beginning of the immersions (min 10; 39 degrees C: 1.9 +/- 1.0 vs. 0.6 +/- 0.3 ng mL(-1), P Immersion in 38 degrees C water did not induce core temperature changes. Peripheral thermoreceptors are involved in GH release when the body is exposed to elevated environmental temperature while a substantial elevation of core temperature is a precondition of PRL release.

Prolonged whole body immersion in cold water: hormonal and metabolic changes.

Science.gov (United States)

Smith, D J; Deuster, P A; Ryan, C J; Doubt, T J

1990-03-01

To characterize metabolic and hormonal responses during prolonged whole body immersion, 16 divers wearing dry suits completed four immersions in 5 degrees C water during each of two 5-day air saturation dives at 6.1 meters of sea water. One immersion began in the AM (1000 h) and one began in the PM (2200 h) to evaluate diurnal variations. Venous blood samples were obtained before and after completion of each immersion. Cortisol and ACTH levels demonstrated diurnal variation, with larger increases occurring after PM immersions. A greater than three-fold postimmersion increase occurred in norepinephrine (NE). There were significant increases in triiodothyronine (T3) uptake and epinephrine, but no change in T3, thyroxine, thyrotrophic hormone, and dopamine. Postimmersion free fatty acid levels increased 409% from preimmersion levels; glucose levels declined, and lactate increased significantly. Only changes in NE correlated significantly with changes in rectal temperature. In summary, when subjects are immersed in cold water for prolonged periods, with a slow rate of body cooling afforded by thermal protection and intermittent exercise, hormonal and metabolic changes occur that are similar in direction and magnitude to short-duration unprotected exposures. Except for cortisol and ACTH, none of the other measured variables exhibited diurnal alterations.

Thermal effects of dorsal head immersion in cold water on nonshivering humans.

Science.gov (United States)

Giesbrecht, Gordon G; Lockhart, Tamara L; Bristow, Gerald K; Steinman, Allan M

2005-11-01

Personal floatation devices maintain either a semirecumbent flotation posture with the head and upper chest out of the water or a horizontal flotation posture with the dorsal head and whole body immersed. The contribution of dorsal head and upper chest immersion to core cooling in cold water was isolated when the confounding effect of shivering heat production was inhibited with meperidine (Demerol, 2.5 mg/kg). Six male volunteers were immersed four times for up to 60 min, or until esophageal temperature = 34 degrees C. An insulated hoodless dry suit or two different personal floatation devices were used to create four conditions: 1) body insulated, head out; 2) body insulated, dorsal head immersed; 3) body exposed, head (and upper chest) out; and 4) body exposed, dorsal head (and upper chest) immersed. When the body was insulated, dorsal head immersion did not affect core cooling rate (1.1 degrees C/h) compared with head-out conditions (0.7 degrees C/h). When the body was exposed, however, the rate of core cooling increased by 40% from 3.6 degrees C/h with the head out to 5.0 degrees C/h with the dorsal head and upper chest immersed (P immersed (approximately 10%). The exaggerated core cooling during dorsal head immersion (40% increase) may result from the extra heat loss affecting a smaller thermal core due to intense thermal stimulation of the body and head and resultant peripheral vasoconstriction. Dorsal head and upper chest immersion in cold water increases the rate of core cooling and decreases potential survival time.

The effect of water immersion on short-latency somatosensory evoked potentials in human

Directory of Open Access Journals (Sweden)

Sato Daisuke

2012-01-01

Full Text Available Abstract Background Water immersion therapy is used to treat a variety of cardiovascular, respiratory, and orthopedic conditions. It can also benefit some neurological patients, although little is known about the effects of water immersion on neural activity, including somatosensory processing. To this end, we examined the effect of water immersion on short-latency somatosensory evoked potentials (SEPs elicited by median nerve stimuli. Short-latency SEP recordings were obtained for ten healthy male volunteers at rest in or out of water at 30°C. Recordings were obtained from nine scalp electrodes according to the 10-20 system. The right median nerve at the wrist was electrically stimulated with the stimulus duration of 0.2 ms at 3 Hz. The intensity of the stimulus was fixed at approximately three times the sensory threshold. Results Water immersion significantly reduced the amplitudes of the short-latency SEP components P25 and P45 measured from electrodes over the parietal region and the P45 measured by central region. Conclusions Water immersion reduced short-latency SEP components known to originate in several cortical areas. Attenuation of short-latency SEPs suggests that water immersion influences the cortical processing of somatosensory inputs. Modulation of cortical processing may contribute to the beneficial effects of aquatic therapy. Trial Registration UMIN-CTR (UMIN000006492

Influence of pyridostigmine bromide on human thermoregulation during cold-water immersion

Energy Technology Data Exchange (ETDEWEB)

Cadarette, B.S.; Prusaczyk, W.K.; Sawka, M.N. (Army Research Inst. of Environmental Medicine, Natick, MA (United States))

1991-03-11

This study examined the effects of an oral 30 mg dose of pyridostigmine bromide (PYR) on thermoregulatory and physiological responses during cold stress. Six men were immersed in chilled stirred water for up to 180 minutes; once 2 hours following ingestion of PYR and once 2 hours following ingestion of a placebo (CON). With PYR, mean ({plus minus} SD) red blood cell cholinesterase inhibition was 33 ({plus minus}12)% at 110 minutes post-ingestion. Cholinesterase inhibition was negatively related to lean body mass. Abdominal discomfort caused termination in 3 of 6 PYR experiments ({bar X} immersion time = 117 min) but in no CON experiments ({bar X} immersion time = 142 min, p > 0.05). During immersion, metabolic rate increased significantly over pre-immersion levels, and increased with duration of immersion, but did not differ between conditions. PYR had no significant effect on rectal temperature, mean body temperature, thermal sensation, heart rate, or plasma cortisol concentration. It was concluded that a 30 mg dose of PYR does not increase susceptibility to hypothermia in humans immersed in cold-water; however, in combination with cold-stress, PYR may result in marked abdominal cramping and limit cold tolerance.

Body cooling in human males by cold-water immersion after vigorous exercise.

Science.gov (United States)

McDonald, A; Goode, R C; Livingstone, S D; Duffin, J

1984-03-01

Five male subjects were immersed to neck level in a whole-body water calorimeter (water temperature 19 degrees C) on two occasions. One immersion was preceded by 30 min of exercise on a treadmill at 80% of the subjects' maximum heart rate, while the other was preceded by no exercise (control). Ventilation, oxygen consumption, hand-grip strength, and heat loss (measured by calorimetry) results showed no significant differences between resting and exercise trials. Minute ventilation and oxygen consumption increased during the immersion but the magnitude of the increase varied among subjects. There was a significant decrease is isometric hand-grip strength after 30 min of immersion. Rectal temperatures fell faster (0.031 degree C +/- 0.004 degree C/min) for exercised subjects than for controls (0.019 degree C +/- 0.005 degree C/min) between 10 and 45 min of immersion (P less than 0.01). It appears that vigorous preimmersion exercise may shorten survival time in cold water due to an increase in cooling rate.

Influence of cold-water immersion on limb blood flow after resistance exercise.

Science.gov (United States)

Mawhinney, Chris; Jones, Helen; Low, David A; Green, Daniel J; Howatson, Glyn; Gregson, Warren

2017-06-01

This study determined the influence of cold (8°C) and cool (22°C) water immersion on lower limb and cutaneous blood flow following resistance exercise. Twelve males completed 4 sets of 10-repetition maximum squat exercise and were then immersed, semi-reclined, into 8°C or 22°C water for 10-min, or rested in a seated position (control) in a randomized order on different days. Rectal and thigh skin temperature, muscle temperature, thigh and calf skin blood flow and superficial femoral artery blood flow were measured before and after immersion. Indices of vascular conductance were calculated (flux and blood flow/mean arterial pressure). The colder water reduced thigh skin temperature and deep muscle temperature to the greatest extent (P lower (55%) than the control post-immersion (P water similarly reduce femoral artery and cutaneous blood flow responses but not muscle temperature following resistance exercise.

Heats of immersion in the thorium oxide-water system at elevated temperatures

International Nuclear Information System (INIS)

Holmes, H.F.

1976-01-01

The surface properties of ThO 2 were studied by heat of immersion calorimetry at 25 to 200 0 C. Results show that the integral heat of immersion of thorium oxide contains contributions which reflect considerable interaction with several layers of water adjacent to the oxide surface. It would be desirable to know the heat capacity changes which occur in the multilayer adsorption of water on an oxide surface. However, such data are not available and their acquisition would be an extremely difficult task. Structuring (a negative ΔCp) of several layers of water (by increased hydrogen bonding) adjacent to an oxide surface could explain an increase in the heat of immersion as the immersion temperature is increased. The more energetic, heterogeneous, high-surface-area samples are expected to induce more order in the adjacent water layers than the less energetic samples. This interpretation is similar to that offered for the temperature dependence of the heat of solution of the alkali halides

Rotating shell eggs immersed in hot water for the purpose of pasteurization

Science.gov (United States)

Pasteurization of shell eggs for inactivation of Salmonella using hot water immersion can be used to improve their safety. The rotation of a shell egg immersed in hot water has previously been simulated by computational fluid dynamics (CFD); however, experimental data to verify the results do not ex...

Interleukin-6 responses to water immersion therapy after acute exercise heat stress: a pilot investigation.

Science.gov (United States)

Lee, Elaine C; Watson, Greig; Casa, Douglas; Armstrong, Lawrence E; Kraemer, William; Vingren, Jakob L; Spiering, Barry A; Maresh, Carl M

2012-01-01

Cold-water immersion is the criterion standard for treatment of exertional heat illness. Cryotherapy and water immersion also have been explored as ergogenic or recovery aids. The kinetics of inflammatory markers, such as interleukin-6 (IL-6), during cold-water immersion have not been characterized. To characterize serum IL-6 responses to water immersion at 2 temperatures and, therefore, to initiate further research into the multidimensional benefits of immersion and the evidence-based selection of specific, optimal immersion conditions by athletic trainers. Controlled laboratory study. Human performance laboratory Patients or Other Participants: Eight college-aged men (age = 22 ± 3 years, height = 1.76 ± 0.08 m, mass = 77.14 ± 9.77 kg, body fat = 10% ± 3%, and maximal oxygen consumption = 50.48 ± 4.75 mL·kg(-1) min(-1)). Participants were assigned randomly to receive either cold (11.70°C ± 2.02°C, n = 4) or warm (23.50°C ± 1.00°C, n = 4) water-bath conditions after exercise in the heat (temperature = 37°C, relative humidity = 52%) for 90 minutes or until volitional cessation. Whole-body cooling rates were greater in the cold water-bath condition for the first 6 minutes of water immersion, but during the 90-minute, postexercise recovery, participants in the warm and cold water-bath conditions experienced similar overall whole-body cooling. Heart rate responses were similar for both groups. Participants in the cold water-bath condition experienced an overall slight increase (30.54% ± 77.37%) in IL-6 concentration, and participants in the warm water-bath condition experienced an overall decrease (-69.76% ± 15.23%). We have provided seed evidence that cold-water immersion is related to subtle IL-6 increases from postexercise values and that warmer water-bath temperatures might dampen this increase. Further research will elucidate any anti-inflammatory benefit associated with water-immersion treatment and possible multidimensional uses of cooling

Reduced cerebral perfusion on sudden immersion in ice water: a possible cause of drowning

DEFF Research Database (Denmark)

Mantoni, Teit; Belhage, Bo; Pedersen, Lars M

2007-01-01

Near-drowning incidents and drowning deaths after accidental immersion in open waters have been linked to cold shock response. It consists of inspiratory gasps, hyperventilation, tachycardia, and hypertension in the first 2-3 min of cold-water immersion. This study explored the immediate changes...... in cerebral blood flow velocity (Vmean) during cold-water immersion since cold shock induced hyperventilation may diminish Vmean and lead to syncope and drowning....

Influence of cold water immersion on limb and cutaneous blood flow at rest.

Science.gov (United States)

Gregson, Warren; Black, Mark A; Jones, Helen; Milson, Jordon; Morton, James; Dawson, Brian; Atkinson, Greg; Green, Daniel J

2011-06-01

Cold water immersion reduces exercise-induced muscle damage. Benefits may partly arise from a decline in limb blood flow; however, no study has comprehensively investigated the influence of different degrees of cooling undertaken via cold water immersion on limb blood flow responses. To determine the influence of cold (8°C) and cool (22°C) water immersion on lower limb and cutaneous blood flow. Controlled laboratory study. Nine men were placed in a semireclined position and lowered into 8°C or 22°C water to the iliac crest for two 5-minute periods interspersed with 2 minutes of nonimmersion. Rectal and thigh skin temperature, deep and superficial muscle temperature, heart rate, mean arterial pressure, thigh cutaneous blood velocity (laser Doppler), and superficial femoral artery blood flow (duplex ultrasound) were measured during immersion and for 30 minutes after immersion. Indices of vascular conductance were calculated (flux and blood flow/mean arterial pressure). Reductions in rectal temperature (8°C, 0.2° ± 0.1°C; 22°C, 0.1° ± 0.1°C) and thigh skin temperature (8°C, 6.2° ± 0.5°C; 22°C, 3.2° ± 0.2°C) were greater in 8°C water than in 22°C (P water compared with 22°C (P = .01). These data suggest that immersion at both temperatures resulted in similar whole limb blood flow but, paradoxically, more blood was distributed to the skin in the colder water. This suggests that colder temperatures may be associated with reduced muscle blood flow, which could provide an explanation for the benefits of cold water immersion in alleviating exercise-induced muscle damage in sports and athletic contexts. Colder water temperatures may be more effective in the treatment of exercise-induced muscle damage and injury rehabilitation because of greater reductions in muscle blood flow.

Effect of cold water immersion on repeat cycling performance and thermoregulation in the heat.

Science.gov (United States)

Vaile, Joanna; Halson, Shona; Gill, Nicholas; Dawson, Brian

2008-03-01

To assess the effect of cold water immersion and active recovery on thermoregulation and repeat cycling performance in the heat, ten well-trained male cyclists completed five trials, each separated by one week. Each trial consisted of a 30-min exercise task, one of five 15-min recoveries (intermittent cold water immersion in 10 degrees C, 15 degrees C and 20 degrees C water, continuous cold water immersion in 20 degrees C water or active recovery), followed by 40 min passive recovery, before repeating the 30-min exercise task. Recovery strategy effectiveness was assessed via changes in total work in the second exercise task compared with that in the first. Following active recovery, a mean 4.1% (s = 1.8) less total work (P = 0.00) was completed in the second than in the first exercise task. However, no significant differences in total work were observed between any of the cold water immersion protocols. Core and skin temperature, blood lactate concentration, heart rate, rating of thermal sensation, and rating of perceived exertion were recorded. During both exercise tasks there were no significant differences in blood lactate concentration between interventions; however, following active recovery blood lactate concentration was significantly lower (P immersion protocols. All cold water immersion protocols were effective in reducing thermal strain and were more effective in maintaining subsequent high-intensity cycling performance than active recovery.

Cold-water acclimation does not modify whole-body fluid regulation during subsequent cold-water immersion.

Science.gov (United States)

Stocks, J M; Patterson, M J; Hyde, D E; Jenkins, A B; Mittleman, K D; Taylor, N A S

2004-06-01

We investigated the impact of cold-water acclimation on whole-body fluid regulation using tracer-dilution methods to differentiate between the intracellular and extracellular fluid compartments. Seven euhydrated males [age 24.7 (8.7) years, mass 74.4 (6.4) kg, height 176.8 (7.8) cm, sum of eight skinfolds 107.4 (20.4) mm; mean (SD)] participated in a 14-day cold-water acclimation protocol, with 60-min resting cold-water stress tests [CWST; 18.1 (0.1) degrees C] on days 1, 8 and 15, and 90-min resting cold-water immersions [18.4 (0.4) degrees C] on intervening days. Subjects were immersed to the 4th intercostal space. Intracellular and extracellular fluid compartments, and plasma protein, electrolyte and hormone concentrations were investigated. During the first CWST, the intracellular fluid (5.5%) and plasma volumes were reduced (6.1%), while the interstitial fluid volume was simultaneously expanded (5.4%). This pattern was replicated on days 8 and 15, but did not differ significantly among test days. Acclimation did not produce significant changes in the pre-immersion distribution of total body water, or changes in plasma osmolality, total protein, electrolyte, atrial natriuretic peptide or aldosterone concentrations. Furthermore, a 14-day cold-water acclimation regimen did not elicit significant changes in body-fluid distribution, urine production, or the concentrations of plasma protein, electrolytes or the fluid-regulatory hormones. While acclimation trends were not evident, we have confirmed that fluid from extravascular cells is displaced into the interstitium during acute cold-water immersion, both before and after cold acclimation.

Loading forces in shallow water running in two levels of immersion.

Science.gov (United States)

Haupenthal, Alessandro; Ruschel, Caroline; Hubert, Marcel; de Brito Fontana, Heiliane; Roesler, Helio

2010-07-01

To analyse the vertical and anteroposterior components of the ground reaction force during shallow water running at 2 levels of immersion. Twenty-two healthy adults with no gait disorders, who were familiar with aquatic exercises. Subjects performed 6 trials of water running at a self-selected speed in chest and hip immersion. Force data were collected through an underwater force plate and running speed was measured with a photocell timing light system. Analysis of covariance was used for data analysis. Vertical forces corresponded to 0.80 and 0.98 times the subject's body weight at the chest and hip level, respectively. Anteroposterior forces corresponded to 0.26 and 0.31 times the subject's body weight at the chest and hip level, respectively. As the water level decreased the subjects ran faster. No significant differences were found for the force values between the immersions, probably due to variability in speed, which was self-selected. When thinking about load values in water running professionals should consider not only the immersion level, but also the speed, as it can affect the force components, mainly the anteroposterior one. Quantitative data on this subject could help professionals to conduct safer aqua-tic rehabilitation and physical conditioning protocols.

The effect of head-down tilt and water immersion on intracranial pressure in nonhuman primates

Science.gov (United States)

Keil, Lanny C.; Mckeever, Kenneth H.; Skidmore, Michael G.; Hines, John; Severs, Walter B.

1992-01-01

Intracranial pressure (ICP) is investigated in primates during and after -6-deg head-down tilt (HDT) and immersion in water to examine the effects of the headward fluid shift related to spaceflight. Following the HDT the primates are subjected to head-out thermoneutral water immersion, and the ICP is subsequently measured. ICP is found to increase from 3.8 +/- 1.1 to 5.3 +/- 1.3 mm Hg during the horizontal control period. ICP stabilizes at -6.3 +/- 1.3 mm Hg and then increases to -2.2 +/- 1.9 mm Hg during partial immersion, and ICP subsequently returns to preimmersion levels after immersion. These data indicate that exposure to HDT or water immersion lead to an early sharp increase in ICP, and water immersion alone leads to higher ICP levels. A significant conclusion of the work is that the ICP did not approach pathological levels, and this finding is relevant to human spaceflight research.

Heat transfer coefficient: Medivance Arctic Sun Temperature Management System vs. water immersion.

Science.gov (United States)

English, M J; Hemmerling, T M

2008-07-01

To improve heat transfer, the Medivance Arctic Sun Temperature Management System (Medivance, Inc., Louisville, CO, USA) features an adhesive, water-conditioned, highly conductive hydrogel pad for intimate skin contact. This study measured and compared the heat transfer coefficient (h), i.e. heat transfer efficiency, of this pad (hPAD), in a heated model and in nine volunteers' thighs; and of 10 degrees C water (hWATER) in 33 head-out immersions by 11 volunteers. Volunteer studies had ethical approval and written informed consent. Calibrated heat flux transducers measured heat flux (W m-2). Temperature gradient (DeltaT) was measured between skin and pad or water temperatures. Temperature gradient was changed through the pad's water temperature controller or by skin cooling on immersion. The heat transfer coefficient is the slope of W m-2/DeltaT: its unit is W m-2 degrees C-1. Average with (95% CI) was: model, hPAD = 110.4 (107.8-113.1), R2 = 0.99, n = 45; volunteers, hPAD = 109.8 (95.5-124.1), R2 = 0.83, n = 51; and water immersion, hWATER = 107.1 (98.1-116), R2 = 0.86, n = 94. The heat transfer coefficient for the pad was the same in the model and volunteers, and equivalent to hWATER. Therefore, for the same DeltaT and heat transfer area, the Arctic Sun's heat transfer rate would equal water immersion. This has important implications for body cooling/rewarming rates.

Cold water immersion of the ankle decreases neuromuscular response of lower limb after inversion movement.

Science.gov (United States)

Macedo, Christiane S G; Alonso, Carolina S; Liporaci, Rogério F; Vieira, Fernando; Guirro, Rinaldo R J

2014-01-01

Cryotherapy has been associated with a significant decrease in nerve conduction velocity and muscle contraction with possible effects on exercise and physical training. To quantify the electromyographic response of the lateral gastrocnemius, tibialis anterior, fibularis longus, rectus femoris and gluteus medius to ankle inversion following cold water immersion. The peak values of the root mean square (RMS) were obtained from 35 healthy and active university subjects after the use of a tilt platform to force the ankle into 30° of inversion before, immediately after, and 10, 20, and 30 minutes after water immersion at 4±2°C, for 20 minutes. The Shapiro-Wilk test, repeated measures analysis, Bonferroni's post-hoc, and linear regression analysis provided the results. Peak RMS was significantly lower at all times after cold water immersion, with residual effect of up to 30 minutes, when compared to pre-immersion for all muscles, except for immediate post-immersion for the gluteus medius. After cold water immersion of the ankle, special care should be taken in activities that require greater neuromuscular control.

Habituation of the initial responses to cold water immersion in humans: a central or peripheral mechanism?

Science.gov (United States)

Tipton, M J; Eglin, C M; Golden, F S

1998-10-15

1. The initial respiratory and cardiac responses to cold water immersion are thought to be responsible for a significant number of open water deaths each year. Previous research has demonstrated that the magnitude of these responses can be reduced by repeated immersions in cold waterwhether the site of habituation is central or peripheral. 2. Two groups of subjects undertook two 3 min head-out immersions in stirred water at 10 C of the right-hand side of the body (R). Between these two immersions (3 whole days) the control group (n = 7) were not exposed to cold water, but the habituation group (n = 8) undertook a further six 3 min head-out immersions in stirred water at 10 C of the left-hand side of the body (L). 3. Repeated L immersions reduced (P immersion a reduction (P < 0.05) in the magnitude of the responses evoked was seen in the habituation group but not in the control group, despite both groups having identical skin temperature profiles. 4. It is concluded that the mechanisms involved in producing habituation of the initial responses are located more centrally than the peripheral receptors.

Postexercise cold-water immersion improves intermittent high-intensity exercise performance in normothermia.

Science.gov (United States)

McCarthy, Avina; Mulligan, James; Egaña, Mikel

2016-11-01

A brief cold water immersion between 2 continuous high-intensity exercise bouts improves the performance of the latter compared with passive recovery in the heat. We investigated if this effect is apparent in normothermic conditions (∼19 °C), employing an intermittent high-intensity exercise designed to reflect the work performed at the high-intensity domain in team sports. Fifteen young active men completed 2 exhaustive cycling protocols (Ex1 and Ex2: 12 min at 85% ventilatory threshold (VT) and then an intermittent exercise alternating 30-s at 40% peak power (P peak ) and 30 s at 90% P peak to exhaustion) separated by 15 min of (i) passive rest, (ii) 5-min cold-water immersion at 8 °C, and (iii) 10-min cold-water immersion at 8 °C. Core temperature, heart rate, rates of perceived exertion, and oxygen uptake kinetics were not different during Ex1 among conditions. Time to failure during the intermittent exercise was significantly (P immersions (7.2 ± 3.5 min and 7.3 ± 3.3 min, respectively) compared with passive rest (5.8 ± 3.1 min). Core temperature, heart rate, and rates of perceived exertion were significantly (P immersions compared with passive rest. The time constant of phase II oxygen uptake response during the 85% VT bout of Ex2 was not different among the 3 conditions. A postexercise, 5- to 10-min cold-water immersion increases subsequent intermittent high-intensity exercise compared with passive rest in normothermia due, at least in part, to reductions in core temperature, circulatory strain, and effort perception.

Long term immersion test of aluminum alloy AA 6061 used for fuel cladding in MTR type reactors

International Nuclear Information System (INIS)

Linardi, Evelina M.; Rodriguez, Sebastian; Haddad, Roberto; Lanzani, Liliana

2009-01-01

In this work we present the results of long term immersion tests performed in the aluminum alloy AA 6061, used for fuel cladding in MTR type reactors. The tests were performed at open circuit potential in high purity water (ρ = 18.2 MΩ.cm) and in 10 -3 M NaCl solution. Two kinds of assemblies were studied: simple sheets and artificial crevices, immersed during 6, 12 and 18 months at room temperature. In both media and both assemblies, the aluminum hydroxide phases crystalline bayerite and bohemite were identified. It was found that a kind of localized attack named alkaline attack occurs around the iron-rich intermetallics. These particles were confirmed to control the corrosion of the AA 6061 alloy in an aerated medium. Immersion times for up to 18 months did not increase the oxide growth or the alkaline attack on the AA 6061 alloy. (author)

Cooling hyperthermic firefighters by immersing forearms and hands in 10 degrees C and 20 degrees C water.

Science.gov (United States)

Giesbrecht, Gordon G; Jamieson, Christopher; Cahill, Farrell

2007-06-01

Firefighters experience significant heat stress while working with heavy gear in a hot, humid environment. This study compared the cooling effectiveness of immersing the forearms and hands in 10 and 20 degrees C water. Six men (33 +/- 10 yr; 180 +/- 4 cm; 78 +/- 9 kg; 19 +/- 5% body fat) wore firefighter 'turn-out gear' (heavy clothing and breathing apparatus weighing 27 kg) in a protocol including three 20-min exercise bouts (step test, 78 W, 40 degrees C air, 40% RH) each followed by a 20-min rest/cooling (21 degrees C air); i.e., 60 min of exercise, 60 min of cooling. Turn-out gear was removed during rest/cooling periods and subjects either rested (Control), immersed their hands in 10 or 20 degrees C water (H-10, H-20), or immersed their hands and forearms in 10 or 20 degrees C water (HF-10, HF-20). In 20 degrees C water, hand immersion did not reduce core temperature compared with Control; however, including forearm immersion decreased core temperature below Control values after both the second and final exercise periods (p hand immersion produced a lower core temperature (0.8 degrees C above baseline) than all other conditions (1.1 to 1.4 degrees C above baseline) after the final exercise period (p Hand and forearm immersion in cool water is simple, reduces heat strain, and may increase work performance in a hot, humid environment. With 20 degrees C water, forearms should be immersed with the hands to be effective. At lower water temperatures, forearm and/or hand immersion will be effective, although forearm immersion will decrease core temperature further.

Facial immersion in cold water enhances cerebral blood velocity during breath-hold exercise in humans

DEFF Research Database (Denmark)

Kjeld, Thomas; Pott, Frank C; Secher, Niels H

2009-01-01

The diving response is initiated by apnea and facial immersion in cold water and includes, besides bradycardia, peripheral vasoconstriction, while cerebral perfusion may be enhanced. This study evaluated whether facial immersion in 10 degrees C water has an independent influence on cerebral...... immersion further increased MCA V(mean) to 122 cm/s ( approximately 88%; both P ... 180-W exercise (from 47 to 53 cm/s), and this increment became larger with facial immersion (76 cm/s, approximately 62%; P 100% increase in MCA V(mean), largely...

Cardiovascular and ventilatory responses to dorsal, facial, and whole-head water immersion in eupnea.

Science.gov (United States)

Gagnon, Dominique D; Pretorius, Thea; McDonald, Gerren; Kenny, Glen P; Giesbrecht, Gordon G

2013-06-01

Facial cooling can regulate reflexes of the dive response whereas further body cooling generally induces the cold-shock response. We examined the cardiovascular and ventilatory parameters of these responses during 3-min immersions of the head dorsum, face, and whole head in 17 degrees C water while breathing was maintained. From a horizontal position, the head was inserted into a temperature controlled immersion tank in which the water level could be changed rapidly. On four occasions, either the head dorsum, face or whole head (prone and supine) were exposed to water. Mean decrease in heart rate (14%) and increases in systolic (9%) and diastolic (5%) blood pressures were seen during immersion. Relative mean finger skin blood flow had an early transient decrease (31%) for 90 s and then returned to baseline values. A strong transient increase was seen in minute ventilation (92%) at 20 s of immersion via tidal volume (85%). There were no consistent differences between the head dorsum, face, and whole head for all variables in response to immersion. The cold-shock response (increased minute ventilation and tidal volume) predominated over the dive response in the initial moments of immersion only. The order of emergence of these responses provides further recommendation to avoid head submersion upon cold water entry. It is important to protect the face, with a facemask, and the head dorsum, with an insulative hood, in cold water.

Immune changes during whole body hot water immersion: the role of growth hormone.

Science.gov (United States)

Kappel, M; Poulsen, T D; Hansen, M B; Galbo, H; Pedersen, B K

1997-07-01

Studies examined the role of growth hormone, catecholamines, and beta-endorphins in changes in natural killer cell activity, subtypes of blood mononuclear cells, and leukocyte concentration in response to hot water immersion in humans. The response of leukocytes and neutrophils to 2 hours of hot water immersion and simultaneous administration of propranolol, somatostatin, naloxone, or isotonic saline are reported.

Effect of a 5-min cold-water immersion recovery on exercise performance in the heat.

Science.gov (United States)

Peiffer, J J; Abbiss, C R; Watson, G; Nosaka, K; Laursen, P B

2010-05-01

This study examined the effect of a 5-min cold-water immersion (14 degrees C) recovery intervention on repeated cycling performance in the heat. 10 male cyclists performed two bouts of a 25-min constant-paced (254 (22) W) cycling session followed by a 4-km time trial in hot conditions (35 degrees C, 40% relative humidity). The two bouts were separated by either 15 min of seated recovery in the heat (control) or the same condition with 5-min cold-water immersion (5th-10th minute), using a counterbalanced cross-over design (CP(1)TT(1) --> CWI or CON --> CP(2)TT(2)). Rectal temperature was measured immediately before and after both the constant-paced sessions and 4-km timed trials. Cycling economy and Vo(2) were measured during the constant-paced sessions, and the average power output and completion times were recorded for each time trial. Compared with control, rectal temperature was significantly lower (0.5 (0.4) degrees C) in cold-water immersion before CP(2) until the end of the second 4-km timed trial. However, the increase in rectal temperature (0.5 (0.2) degrees C) during CP(2) was not significantly different between conditions. During the second 4-km timed trial, power output was significantly greater in cold-water immersion (327.9 (55.7) W) compared with control (288.0 (58.8) W), leading to a faster completion time in cold-water immersion (6.1 (0.3) min) compared with control (6.4 (0.5) min). Economy and Vo(2) were not influenced by the cold-water immersion recovery intervention. 5-min cold-water immersion recovery significantly lowered rectal temperature and maintained endurance performance during subsequent high-intensity exercise. These data indicate that repeated exercise performance in heat may be improved when a short period of cold-water immersion is applied during the recovery period.

Cold water immersion of the ankle decreases neuromuscular response of lower limb after inversion movement

Directory of Open Access Journals (Sweden)

Christiane S. G. Macedo

2014-03-01

Full Text Available BACKGROUND: Cryotherapy has been associated with a significant decrease in nerve conduction velocity and muscle contraction with possible effects on exercise and physical training. OBJECTIVES: To quantify the electromyographic response of the lateral gastrocnemius, tibialis anterior, fibularis longus, rectus femoris and gluteus medius to ankle inversion following cold water immersion. METHOD: The peak values of the root mean square (RMS were obtained from 35 healthy and active university subjects after the use of a tilt platform to force the ankle into 30° of inversion before, immediately after, and 10, 20, and 30 minutes after water immersion at 4±2°C, for 20 minutes. The Shapiro-Wilk test, repeated measures analysis, Bonferroni's post-hoc, and linear regression analysis provided the results. RESULTS: Peak RMS was significantly lower at all times after cold water immersion, with residual effect of up to 30 minutes, when compared to pre-immersion for all muscles, except for immediate post-immersion for the gluteus medius. CONCLUSIONS: After cold water immersion of the ankle, special care should be taken in activities that require greater neuromuscular control.

Water immersion during labor and birth: is there an extra cost for hospitals?

Science.gov (United States)

Poder, Thomas G

2017-06-01

Water immersion during labor and birth is growing in popularity, and many hospitals are now considering offering this service to laboring women. Some advantages of water immersion are demonstrated, but others remain uncertain, and particularly, few studies have examined the financial impact of such a device on hospitals. This study simulated what could be the extra cost of water immersion for hospitals. Clinical outcomes were drawn from the results of systematic reviews already published, and cost units were those used in the Quebec health network. A decision tree was used with microsimulations of representative laboring women. Sensitivity analyses were performed as regards analgesic use and labor duration. Microsimulations indicated an extra cost between $166.41 and $274.76 (2014 Canadian dollars) for each laboring woman as regards the scenario considered. The average extra cost was $221.12 (95% confidence interval, 219.97-222.28). While water immersion allows better clinical outcomes, implementation and other costs are higher than the savings generated, which leads to a small extra cost to allow women to potentially have more relaxation and less pain. © 2016 John Wiley & Sons, Ltd.

Bonding capacity of the GFRP-S on strengthened RC beams after sea water immersion

Science.gov (United States)

Sultan, Mufti Amir; Djamaluddin, Rudy

2017-11-01

Construction of concrete structures that located in extreme environments are such as coastal areas will result in decreased strength or even the damage of the structures. As well know, chloride contained in sea water is responsible for strength reduction or structure fail were hence maintenance and repairs on concrete structure urgently needed. One popular method of structural improvements which under investigation is to use the material Glass Fibre Reinforced Polymer which has one of the advantages such as corrosion resistance. This research will be conducted experimental studies to investigate the bonding capacity behavior of reinforced concrete beams with reinforcement GFRP-S immersed in sea water using immersion time of one month, three months, six months and twelve months. Test specimen consists of 12 pieces of reinforced concrete beams with dimensions (150x200x3000) mm that had been reinforced with GFRP-S in the area of bending, the beam without immersion (B0), immersion one month (B1), three months (B3), six months (B6) and twelve months (B12). Test specimen were cured for 28 days before the application of the GFRP sheet. Test specimen B1, B3, B6 and B12 that have been immersed in sea water pool with a immersion time each 1, 3, 6 and 12 months. The test specimen without immersion test by providing a static load until it reaches the failure, to record data during the test strain gauge mounted on the surface of the specimen and the GFRP to collect the strain value. From the research it obvious that there is a decrease bonding capacity on specimens immersed for one month, three months, six months and twelve months against the test object without immersion of 8.85%; 8.89%; 9.33% and 11.04%.

Degradation of Epoxy-Steel Single Lap Joints Immersed in Water

DEFF Research Database (Denmark)

Goglio, L; Rezaei, Mohsen

2015-01-01

Exposure to environmental factors, especially moisture, is recognized as the major cause of degradation of adhesive joints. In this work, complementing a previous study on exposure to moisture, single lap joints were subjected to immersion in water, up to five weeks, at room temperature and 50 °C....... The material of the adherends was mild steel, and the adhesive was a bi-component epoxy. The specimens were fabricated using the open-face technique. Mechanical testing at the end of the relevant period of immersion showed an initial loss of ultimate load, after one week at 50 °C or two at room temperature......; then, the strength remained practically constant over the remaining time. The loss was more accentuated after immersion at 50 °C, about 70%, than at room temperature, about 30%. Also a reduction in stiffness of the joints was measured, again dramatic (about 70%) after immersion at 50 °C, moderate...

Spectral-directional reflectivity of Tyvek immersed in water

CERN Document Server

Filevich, A; Bianchi, H; Rodríguez-Martino, J; Torlasco, G

1999-01-01

Spectral-directional relative intensity of the light scattered by a Tyvek sample, immersed in water, has been measured for visible and UV wavelengths. The obtained information is useful to simulate the behavior of light in water Cherenkov detectors, such as those proposed for the observation of high energy cosmic ray air showers. In this work a simple empirical dependence of the scattering pattern on the angle was found, convenient to be used in Monte Carlo simulation programs.

Numerical Investigation on Effect of Immersed Blade Depth on the Performance of Undershot Water Turbines

Directory of Open Access Journals (Sweden)

Yah Nor Fadilah

2016-01-01

Full Text Available Energy, especially electricity, plays a vital role in global social and economic development. High annual rain rate in Malaysia seems a good potential for electricity generation especially through small hydro powers. Undershot water turbines are one of the hydropower turbines used for many years. However, the effect of blade depth immersed in the flowing water is not fully investigated. Therefore, the purpose of this paper is to study the effect of immersed blade depth for straight blade undershot water turbine in power generation by using Computational Fluid Dynamics (CFD method. ANSYS CFX 15.0 was used to perform three dimensional analysis under steady state, incompressible, and non-isothermal conditions. The water wheel with number of blades of 6 and four different immersed depth was applied for each simulation. There are four different immersed depth was applied to each simulation, which are 20 mm, 40 mm, 60 mm and 80 mm. From the simulation result, it was found that the optimum immersed depth is 40 mm where the torque load and power generated were 0.264 N.m and 1.318 Watt respectively.

Atrial distension, haemodilution, and acute control of renin release during water immersion in humans

DEFF Research Database (Denmark)

Gabrielsen, A; Pump, B; Bie, P

2002-01-01

immersion. During WI, central venous pressure (CVP) and left atrial diameter (LAD) increased (P ... is not the single pivotal stimulus for the acute suppression of renin release in response to intravascular volume expansion by water immersion in humans. Haemodilution constitutes a significant and conceivably the principal stimulus for the acute immersion-induced suppression of renin-angiotensin system activity....

Optimizing Cold Water Immersion for Exercise-Induced Hyperthermia: A Meta-analysis.

Science.gov (United States)

Zhang, Yang; Davis, Jon-Kyle; Casa, Douglas J; Bishop, Phillip A

2015-11-01

Cold water immersion (CWI) provides rapid cooling in events of exertional heat stroke. Optimal procedures for CWI in the field are not well established. This meta-analysis aimed to provide structured analysis of the effectiveness of CWI on the cooling rate in healthy adults subjected to exercise-induced hyperthermia. An electronic search (December 2014) was conducted using the PubMed and Web of Science. The mean difference of the cooling rate between CWI and passive recovery was calculated. Pooled analyses were based on a random-effects model. Sources of heterogeneity were identified through a mixed-effects model Q statistic. Inferential statistics aggregated the CWI cooling rate for extrapolation. Nineteen studies qualified for inclusion. Results demonstrate CWI elicited a significant effect: mean difference, 0.03°C·min(-1); 95% confidence interval, 0.03-0.04°C·min(-1). A conservative, observed estimate of the CWI cooling rate was 0.08°C·min(-1) across various conditions. CWI cooled individuals twice as fast as passive recovery. Subgroup analyses revealed that cooling was more effective (Q test P immersion water temperature ≤10°C, ambient temperature ≥20°C, immersion duration ≤10 min, and using torso plus limbs immersion. There is insufficient evidence of effect using forearms/hands CWI for rapid cooling: mean difference, 0.01°C·min(-1); 95% confidence interval, -0.01°C·min(-1) to 0.04°C·min(-1). A combined data summary, pertaining to 607 subjects from 29 relevant studies, was presented for referencing the weighted cooling rate and recovery time, aiming for practitioners to better plan emergency procedures. An optimal procedure for yielding high cooling rates is proposed. Using prompt vigorous CWI should be encouraged for treating exercise-induced hyperthermia whenever possible, using cold water temperature (approximately 10°C) and maximizing body surface contact (whole-body immersion).

The Effects of Multiple Cold Water Immersions on Indices of Muscle Damage

Science.gov (United States)

Goodall, Stuart; Howatson, Glyn

2008-01-01

The aim of this investigation was to elucidate the efficacy of repeated cold water immersions (CWI) in the recovery of exercise induced muscle damage. A randomised group consisting of eighteen males, mean ± s age, height and body mass were 24 ± 5 years, 1.82 ± 0.06 m and 85.7 ± 16.6 kg respectively, completed a bout of 100 drop jumps. Following the bout of damaging exercise, participants were randomly but equally assigned to either a 12 min CWI (15 ± 1 °C; n = 9) group who experienced immersions immediately post-exercise and every 24 h thereafter for the following 3 days, or a control group (no treatment; n = 9). Maximal voluntary contraction (MVC) of the knee extensors, creatine kinase activity (CK), muscle soreness (DOMS), range of motion (ROM) and limb girth were measured pre-exercise and then for the following 96 h at 24 h increments. In addition MVC was also recorded immediately post-exercise. Significant time effects were seen for MVC, CK, DOMS and limb girth (p 0.05). These results suggest that repeated CWI do not enhance recovery from a bout of damaging eccentric contractions. Key pointsCryotherapy, particularly cold water immersions are one of the most common interventions used in order to enhance recovery post-exercise.There is little empirical evidence demonstrating benefits from cold water immersions. Research evidence is equivocal, probably due to methodological inconsistencies.Our results show that the cryotherapy administered did not attenuate any markers of EIMD or enhance the recovery of function.We conclude that repeated cold water immersions are ineffective in the recovery from heavy plyometric exercise and suggest athletes and coaches should use caution before using this intervention as a recovery strategy PMID:24149455

Substantive hemodynamic and thermal strain upon completing lower-limb hot-water immersion; comparisons with treadmill running.

Science.gov (United States)

Thomas, Kate N; van Rij, André M; Lucas, Samuel J E; Gray, Andrew R; Cotter, James D

2016-01-01

Exercise induces arterial flow patterns that promote functional and structural adaptations, improving functional capacity and reducing cardiovascular risk. While heat is produced by exercise, local and whole-body passive heating have recently been shown to generate favorable flow profiles and associated vascular adaptations in the upper limb. Flow responses to acute heating in the lower limbs have not yet been assessed, or directly compared to exercise, and other cardiovascular effects of lower-limb heating have not been fully characterized. Lower-limb heating by hot-water immersion (30 min at 42°C, to the waist) was compared to matched-duration treadmill running (65-75% age-predicted heart rate maximum) in 10 healthy, young adult volunteers. Superficial femoral artery shear rate assessed immediately upon completion was increased to a greater extent following immersion (mean ± SD: immersion +252 ± 137% vs. exercise +155 ± 69%, interaction: p = 0.032), while superficial femoral artery flow-mediated dilation was unchanged in either intervention. Immersion increased heart rate to a lower peak than during exercise (immersion +38 ± 3 beats·min -1 vs. exercise +87 ± 3 beats·min -1 , interaction: p immersion reduced mean arterial pressure after exposure (-8 ± 3 mmHg, p = 0.012). Core temperature increased twice as much during immersion as exercise (+1.3 ± 0.4°C vs. +0.6 ± 0.4°C, p immersion has potential to induce favorable shear stress patterns and cardiovascular responses within vessels prone to atherosclerosis. Whether repetition of lower-limb heating has long-term beneficial effects in such vasculature remains unexplored.

Mechanical properties of water hyacinth fibers – polyester composites before and after immersion in water

International Nuclear Information System (INIS)

Abral, H.; Kadriadi, D.; Rodianus, A.; Mastariyanto, P.; Ilhamdi; Arief, S.; Sapuan, S.M.; Ishak, M.R.

2014-01-01

Highlights: • Moisture absorption of water hyacinth (WH) fibers was measured. • WH fibers polyester composites immersed in water decreased mechanical properties. • Improvement fibers fraction in polyester increases mechanical properties. - Abstract: This study reported moisture absorption of untreated and treated individual water hyacinth (WH) fibers as well as comparison the mechanical properties of WH fibers – unsaturated polyester (UPR) matrix composites after and before immersion in water. The result shows that the individual WH fibers treated with various alkali concentration did not exhibit significantly decreases of their moisture absorption. SEM photograph in cross section of the treated WH fibers shows swollen cell wall containing more nano and micro hollows. Tensile and flexure strength of the wet composite samples are lower than that of dried ones. However, increases volume fraction of the WH fibers in UPR matrix affected slightly on enhancement mechanical properties of the composite samples

Cardiovascular response to apneic immersion in cool and warm water

Science.gov (United States)

Folinsbee, L.

1974-01-01

The influence of prior exposure to cool water and the influence of lung volume on the responses to breath holding were examined. The bradycardia and vasoconstriction that occur during breath-hold diving in man are apparently the resultant of stimuli from apnea, relative expansion of the thorax, lung volume, esophageal pressure, face immersion, and thermal receptor stimulation. It is concluded that the bradycardia and vasoconstriction associated with breath holding during body immersion are not attenuated by a preexisting bradycardia and vasoconstriction due to cold.

Effect of PAC addition on immersed ultrafiltration for the treatment of algal-rich water

Energy Technology Data Exchange (ETDEWEB)

Zhang Yan, E-mail: zhang.yan113@163.com [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 73 Huanghe Road, Nangang District, Harbin 150090 (China); Tian Jiayu; Nan Jun; Gao Shanshan; Liang Heng; Wang Meilian; Li Guibai [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, 73 Huanghe Road, Nangang District, Harbin 150090 (China)

2011-02-28

The aim of this study was to evaluate the effect of powdered activated carbon (PAC) addition on the treatment of algal-rich water by immersed ultrafiltration (UF), in terms of permeate quality and membrane fouling. Experiments were performed with a hollow-fiber polyvinyl chloride ultrafiltration membrane at a laboratory scale, 20-25 deg, C and 10 L/(m{sup 2} h) constant permeate flux. UF could achieve an absolute removal of Microcystis aeruginosa cells, but a poor removal of algogenic organic matter (AOM) released into water, contaminants responsible for severe membrane fouling. The addition of 4 g/L PAC to the immersed UF reactor significantly alleviated the development of trans-membrane pressure and enhanced the removal of dissovled organic carbon (by 10.9 {+-} 1.7%), UV{sub 254} (by 27.1 {+-} 1.7%), and microcystins (expressed as MC-LR{sub eq}, by 40.8 {+-} 4.2%). However, PAC had little effect on the rejection of hydrophilic high molecular weight AOM such as carbohydrates and proteins. It was also identified that PAC reduced the concentrations of carbohydrates and proteins in the reactor due to decreased light intensity, as well as the MC-LR{sub eq} concentration by PAC adsorption.

The physiological response to cold-water immersion following a mixed martial arts training session.

Science.gov (United States)

Lindsay, Angus; Carr, Sam; Cross, Sean; Petersen, Carl; Lewis, John G; Gieseg, Steven P

2017-05-01

Combative sport is one of the most physically intense forms of exercise, yet the effect of recovery interventions has been largely unexplored. We investigated the effect of cold-water immersion on structural, inflammatory, and physiological stress biomarkers following a mixed martial arts (MMA) contest preparation training session in comparison with passive recovery. Semiprofessional MMA competitors (n = 15) were randomly assigned to a cold-water immersion (15 min at 10 °C) or passive recovery protocol (ambient air) completed immediately following a contest preparation training session. Markers of muscle damage (urinary myoglobin), inflammation/oxidative stress (urinary neopterin + total neopterin (neopterin + 7,8-dihydroneopterin)), and hypothalamic-pituitary axis (HPA) activation (saliva cortisol) were determined before, immediately after, and 1, 2, and 24 h postsession. Ratings of perceived soreness and fatigue, counter movement jump, and gastrointestinal temperature were also measured. Concentrations of all biomarkers increased significantly (p < 0.05) postsession. Cold water immersion attenuated increases in urinary neopterin (p < 0.05, d = 0.58), total neopterin (p < 0.05, d = 0.89), and saliva cortisol after 2 h (p < 0.05, d = 0.68) and urinary neopterin again at 24 h (p < 0.01, d = 0.57) in comparison with passive recovery. Perceived soreness, fatigue, and gastrointestinal temperatures were also lower for the cold-water immersion group at several time points postsession whilst counter movement jump did not differ. Combative sport athletes who are subjected to impact-induced stress may benefit from immediate cold-water immersion as a simple recovery intervention that reduces delayed onset muscle soreness as well as macrophage and HPA activation whilst not impairing functional performance.

Effect of gender, cadence, and water immersion on ground reaction forces during stationary running.

Science.gov (United States)

de Brito Fontana, Heiliane; Haupenthal, Alessandro; Ruschel, Caroline; Hubert, Marcel; Ridehalgh, Colette; Roesler, Helio

2012-05-01

Controlled laboratory study. To analyze the vertical and anteroposterior components of the ground reaction force during stationary running performed in water and on dry land, focusing on the effect of gender, level of immersion, and cadence. Stationary running, as a fundamental component of aquatic rehabilitation and training protocols, is little explored in the literature with regard to biomechanical variables, which makes it difficult to determine and control the mechanical load acting on the individuals. Twenty-two subjects performed 1 minute of stationary running on land, immersed to the hip, and immersed to the chest at 3 different cadences: 90 steps per minute, 110 steps per minute, and 130 steps per minute. Force data were acquired with a force plate, and the variables were vertical peak (Fy), loading rate (LR), anterior peak (Fx anterior), and posterior peak (Fx posterior). Data were normalized to subjects' body weight (BW) and analyzed using repeated-measures analysis of variance. Fy ranged from 0.98 to 2.11 BW, LR ranged from 5.38 to 11.52 BW/s, Fx anterior ranged from 0.07 to 0.14 BW, and Fx posterior ranged from 0.06 to 0.09 BW. The gender factor had no effect on the variables analyzed. A significant interaction between level of immersion and cadence was observed for Fy, Fx anterior, and Fx posterior. On dry land, Fy increased with increasing cadence, whereas in water this effect was seen only between 90 steps per minute and the 2 higher cadences. The higher the level of immersion, the lower the magnitude of Fy. LR was reduced under both water conditions and increased with increasing cadence, regardless of the level of immersion. Ground reaction forces during stationary running are similar between genders. Fy and LR are lower in water, though the values are increased at higher cadences.

Hand immersion in cold water alleviating physiological strain and increasing tolerance to uncompensable heat stress.

Science.gov (United States)

Khomenok, Gennadi A; Hadid, Amir; Preiss-Bloom, Orahn; Yanovich, Ran; Erlich, Tomer; Ron-Tal, Osnat; Peled, Amir; Epstein, Yoram; Moran, Daniel S

2008-09-01

The current study examines the use of hand immersion in cold water to alleviate physiological strain caused by exercising in a hot climate while wearing NBC protective garments. Seventeen heat acclimated subjects wearing a semi-permeable NBC protective garment and a light bulletproof vest were exposed to a 125 min exercise-heat stress (35 degrees C, 50% RH; 5 km/h, 5% incline). The heat stress exposure routine included 5 min rest in the chamber followed by two 50:10 min work-rest cycles. During the control trial (CO), there was no intervention, whilst in the intervention condition the subjects immersed their hands and forearms in a 10 degrees C water bath (HI). The results demonstrated that hand immersion in cold water significantly reduced physiological strain. In the CO exposure during the first and second resting periods, the average rectal temperature (T (re)) practically did not decrease. With hand immersion, the mean (SD) T (re) decreased by 0.45 (0.05 degrees C) and 0.48 degrees C (0.06 degrees C) during the first and second rest periods respectively (P immersion in cold water for 10 min is an effective method for decreasing the physiological strain caused by exercising under heat stress while wearing NBC protective garments. The method is convenient, simple, and allows longer working periods in hot or contaminated areas with shorter resting periods.

EFFECT OF IMMERSION TEMPERATURE ON THE WATER UPTAKE OF POLYPROPYLENE/WOOD FLOUR/ORGANOCLAY HYBRID NANOCOMPOSITE

Directory of Open Access Journals (Sweden)

Behzad Kord

2011-02-01

Full Text Available Polypropylene/wood flour/organoclay hybrid nanocomposites were melt-compounded in an internal mixer at 190 oC and 60 rpm rotor speed. Then samples were fabricated by injection molding. Effects of immersion temperature on the water uptake of hybrid nanocomposite were investigated. To meet this objective, water absorption of samples was determined after 24 h immersion in distilled water at different temperatures (25, 50, 75, and 100 °C. Results indicated that immersion temperature had a significant influence on the water absorption of composites. By increasing the temperature, water absorption increases as well. The maximum water absorption of composite is decreased by increasing the nanoclay and compatibilizer content. The morphology of nanoclay was determined by X-ray diffraction (XRD and transmission electron microscopy. The effect of morphology on water absorption was also evaluated. Due to inadequate compatibilizer, exfoliated morphology of nanoclay was not obtained, but there was evidence of intercalation. The order of intercalation for samples containing 3 phc was higher than that of 6 phc at the same PP-g-MA content due to some agglomerations of organoclay.

Core cooling and thermal responses during whole-head, facial, and dorsal immersion in 17 degrees C water.

Science.gov (United States)

Pretorius, Thea; Gagnon, Dominique D; Giesbrecht, Gordon G

2010-10-01

This study isolated the effects of dorsal, facial, and whole-head immersion in 17 degrees C water on peripheral vasoconstriction and the rate of body core cooling. Seven male subjects were studied in thermoneutral air (approximately 28 degrees C). On 3 separate days, they lay prone or supine on a bed with their heads inserted through the side of an adjustable immersion tank. Following 10 min of baseline measurements, the water level was raised such that the water immersed the dorsum, face, or whole head, with the immersion period lasting 60 min. During the first 30 min, the core (esophageal) cooling rate increased from dorsum (0.29 ± 0.2 degrees C h-1) to face (0.47 ± 0.1 degrees C h-1) to whole head (0.69 ± 0.2 degrees C h(-1)) (p whole-head immersion (114 ± 52% h(-1)) than in either facial (51 ± 47% h-1) or dorsal (41 ± 55% h(-1)) immersion (p whole-head (120.5 ± 13 kJ), facial (86.8 ± 17 kJ), and dorsal (46.0 ± 11 kJ) immersion (p whole head elicited a higher rate of vasoconstriction, the face did not elicit more vasoconstriction than the dorsum. Rather, the progressive increase in core cooling from dorsal to facial to whole-head immersion simply correlates with increased heat loss.

Ground reaction forces in shallow water running are affected by immersion level, running speed and gender.

Science.gov (United States)

Haupenthal, Alessandro; Fontana, Heiliane de Brito; Ruschel, Caroline; dos Santos, Daniela Pacheco; Roesler, Helio

2013-07-01

To analyze the effect of depth of immersion, running speed and gender on ground reaction forces during water running. Controlled laboratory study. Twenty adults (ten male and ten female) participated by running at two levels of immersion (hip and chest) and two speed conditions (slow and fast). Data were collected using an underwater force platform. The following variables were analyzed: vertical force peak (Fy), loading rate (LR) and anterior force peak (Fx anterior). Three-factor mixed ANOVA was used to analyze data. Significant effects of immersion level, speed and gender on Fy were observed, without interaction between factors. Fy was greater when females ran fast at the hip level. There was a significant increase in LR with a reduction in the level of immersion regardless of the speed and gender. No effect of speed or gender on LR was observed. Regarding Fx anterior, significant interaction between speed and immersion level was found: in the slow condition, participants presented greater values at chest immersion, whereas, during the fast running condition, greater values were observed at hip level. The effect of gender was only significant during fast water running, with Fx anterior being greater in the men group. Increasing speed raised Fx anterior significantly irrespective of the level of immersion and gender. The magnitude of ground reaction forces during shallow water running are affected by immersion level, running speed and gender and, for this reason, these factors should be taken into account during exercise prescription. Copyright © 2012 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Effect of long-time immersion of soft denture liners in water on viscoelastic properties.

Science.gov (United States)

Iwasaki, Naohiko; Yamaki, Chisato; Takahashi, Hidekazu; Oki, Meiko; Suzuki, Tetsuya

2017-09-26

Aim of this study was to investigate the effect of long-time immersion of soft denture liners in 37°C water on viscoelastic properties. Six silicone-based and two acrylic resin-based soft denture liners were selected. Cylindrical specimens were stored in distilled water at 37°C for 6 months. Viscoelastic properties, which were instantaneous and delayed elastic displacements, viscous flow, and residual displacement, were determined using a creep meter, and analyzed with 2-way analysis of variance and Tukey's comparison (α=0.05). Viscoelastic properties and their time-dependent changes were varied among materials examined. The observed viscoelastic properties of three from six silicone-based liners did not significantly change after 6-month immersion, but those of two acrylic resin-based liners significantly changed with the increase of immersion time. However, the sum of initial instantaneous elastic displacement and delayed elastic displacement of two acrylic resin-based liners during 6-month immersion changed less than 10%, which might indicate clinically sufficient elastic performance.

Exertional rhabdomyolysis in a collegiate american football player after preventive cold-water immersion: a case report.

Science.gov (United States)

Kahanov, Leamor; Eberman, Lindsey E; Wasik, Mitchell; Alvey, Thurman

2012-01-01

To describe a case of exertional rhabdomyolysis in a collegiate American football player after preventive coldwater immersion. A healthy man (19 years old) participated in full-contact football practice followed by conditioning (2.5 hours). After practice, he entered a coach-mandated postpractice cold-water immersion and had no signs of heat illness before developing leg cramps, for which he presented to the athletic training staff. After 10 minutes of repeated stretching, massage, and replacement of electrolyte-filled fluids, he was transported to the emergency room. Laboratory tests indicated a creatine kinase (CK) level of 2545 IU/L (normal range, 45-260 IU/L), CK-myoglobin fraction of 8.5 ng/mL (normal football practice as tolerated. Two months after the incident, his CK level remained high (1900 IU/L). The athlete demonstrated no signs of heat illness upon entering the cold-water immersion but experienced severe leg cramping after immersion, resulting in a diagnosis of exertional rhabdomyolysis. Previously described cases have not linked cold-water immersion with the pathogenesis of rhabdomyolysis. In this football player, CK levels appeared to be a poor indicator of rhabdomyolysis. Our patient demonstrated no other signs of the illness weeks after the incident, yet his elevated CK levels persisted. Cold-water immersion immediately after exercise should be monitored by the athletic training staff and may not be appropriate to prevent muscle damage, given the lack of supporting evidence.

Effects of Hot Water Immersion on Storage Quality of Fresh Broccoli Heads

Directory of Open Access Journals (Sweden)

Huaqiang Dong

2004-01-01

Full Text Available Freshly harvested broccoli heads were immersed for 0, 1, 4 or 8 min into hot water at 45 °C, and then were hydrocooled rapidly for 10 min at 10 °C. Following these treatments, the broccoli were air-dried for 30 min, then packed in commercial polymeric film bags, and, finally, stored for 16 days at –1, 1, and 12 °C. The samples treated with hot water maintained high contents of chlorophyll concentrations, their yellowing rate was delayed, and fungal infection and chilling or freezing injury were inhibited markedly. Compared to non-heat-treated broccoli, a lower level of peroxidase activity with a relatively higher chlorophyll concentration was observed when broccoli were treated with hot water. Among these heat treatments, immersion in hot water for 4 min at 45 °C was the most effective for maintaining the quality of harvested broccoli heads.

Effects of whole body cryotherapy and cold water immersion on knee skin temperature.

Science.gov (United States)

Costello, J T; Donnelly, A E; Karki, A; Selfe, J

2014-01-01

This study sought to (a) compare and contrast the effect of 2 commonly used cryotherapy treatments, 4 min of -110 °C whole body cryotherapy and 8 °C cold water immersion, on knee skin temperature and (b) establish whether either protocol was capable of achieving a skin temperature (cryotherapy (19.0±0.9 °C) compared to cold water immersion (20.5±0.6 °C). However, from 10 to 60 min post, the average, minimum and maximum skin temperatures were lower (p<0.05) following the cold water treatment. Finally, neither protocol achieved a skin temperature believed to be required to elicit an analgesic effect. © Georg Thieme Verlag KG Stuttgart · New York.

Free cortisol and salivary alpha-amylase levels during a six-hour-water immersion in healthy young men

Science.gov (United States)

Rohleder, N.; Wirth, D.; Fraßl, W.; Kowoll, R.; Schlemmer, M.; Vogler, S.; Kirsch, K. A.; Kirschbaum, C.; Gunga, H.-C.

2005-08-01

Limited data are available on the response of stress systems to microgravity. Increased activity of stress systems is reported during space flight, but unchanged or decreased activity during simulated microgravity. We here investigated the impact of head-out water immersion on the activity of the hypothalamus-pituitary-adrenal (HPA) axis and the sympathetic-adrenal-medullary (SAM) system.Eight healthy young men were exposed to a six-hour water immersion in a thermo neutral bath and a control condition. Saliva samples were taken before, during, and after interventions to assess cortisol as an index for HPA axis activity, and salivary α-amylase as an index for SAM system activity.Cortisol levels uniformly decreased during both conditions. Amylase levels increased during both conditions, but were significantly lower during the first half of water immersion compared to the control condition.In conclusion, the HPA axis is not influenced by simulated microgravity, while SAM system activity shows initial decreases during water immersion.

Exertional Rhabdomyolysis in a Collegiate American Football Player After Preventive Cold-Water Immersion: A Case Report

Science.gov (United States)

Kahanov, Leamor; Eberman, Lindsey E.; Wasik, Mitchell; Alvey, Thurman

2012-01-01

Objective: To describe a case of exertional rhabdomyolysis in a collegiate American football player after preventive cold-water immersion. Background: A healthy man (19 years old) participated in full-contact football practice followed by conditioning (2.5 hours). After practice, he entered a coach-mandated post-practice cold-water immersion and had no signs of heat illness before developing leg cramps, for which he presented to the athletic training staff. After 10 minutes of repeated stretching, massage, and replacement of electrolyte-filled fluids, he was transported to the emergency room. Laboratory tests indicated a creatine kinase (CK) level of 2545 IU/L (normal range, 45–260 IU/L), CK-myoglobin fraction of 8.5 ng/mL (normal rhabdomyolysis. Treatment: The patient was treated with rest and rehydration. One week after the incident, he began biking and swimming. Eighteen days later, the patient continued to demonstrate elevated CK levels (527 IU/L) but described no other symptoms and was allowed to return to football practice as tolerated. Two months after the incident, his CK level remained high (1900 IU/L). Uniqueness: The athlete demonstrated no signs of heat illness upon entering the cold-water immersion but experienced severe leg cramping after immersion, resulting in a diagnosis of exertional rhabdomyolysis. Previously described cases have not linked cold-water immersion with the pathogenesis of rhabdomyolysis. Conclusions: In this football player, CK levels appeared to be a poor indicator of rhabdomyolysis. Our patient demonstrated no other signs of the illness weeks after the incident, yet his elevated CK levels persisted. Cold-water immersion immediately after exercise should be monitored by the athletic training staff and may not be appropriate to prevent muscle damage, given the lack of supporting evidence. PMID:22488291

Changes of brachial arterial doppler waveform during immersion of the hand of young men in ice-cold water

International Nuclear Information System (INIS)

Kim, Young Goo

1994-01-01

To evaluate the changes of brachial arterial Doppler waveform during immersion of the hand of young men in ice-cold water. Doppler waveforms of brachial arteries in 11 young male patients were recorded before and during immersion of ipsilateral hand in ice-cold water(4-5 .deg. C). The procedure was repeated on separate days. Patterns of waveform during immersion were compared with the changes of pulsatility index. Four men showed high impedance waveforms, and 5 men showed low impedance waveforms during immersion both at the first and at the second study. Two men, however, showed high impedance waveforms at the first study and tow impedance waveforms at the second study. The pulsatility index rose and fell in high and low impedance waveforms, respectively. The changes of brachial arterial Doppler waveforms could be classified into high and low impedance patterns, probably reflecting the acute changes in downstream impedance during immersion of hand in ice-cold water

Influence of cold-water immersion on limb and cutaneous blood flow after exercise.

Science.gov (United States)

Mawhinney, Chris; Jones, Helen; Joo, Chang Hwa; Low, David A; Green, Daniel J; Gregson, Warren

2013-12-01

This study aimed to determine the influence of cold (8°C) and cool (22°C) water immersion on femoral artery and cutaneous blood flow after exercise. Twelve men completed a continuous cycle exercise protocol at 70% peak oxygen uptake until a core temperature of 38°C was attained. Subjects were then immersed semireclined into 8°C or 22°C water to the iliac crest for 10 min or rested. Rectal and thigh skin temperature, deep and superficial muscle temperature, thigh and calf skin blood flow (laser Doppler flowmetry), and superficial femoral artery blood flow (duplex ultrasound) were measured before and up to 30 min after immersion. Indices of vascular conductance were calculated (flux and blood flow/mean arterial pressure). Reductions in rectal temperature were similar (0.6°C-0.7°C) in all three trials (P = 0.38). The mean ± SD thigh skin temperature during recovery was 25.4°C ± 3.8°C in the 8°C trial, which was lower than the 28.2°C ± 1.4°C and 33.78°C ± 1.0°C in the 22°C and control trials, respectively (P lower (∼55%) compared with the control condition 30 min after immersion (P water temperatures may be more effective in the treatment of exercise-induced muscle damage and injury rehabilitation by virtue of greater reductions in muscle temperature and not muscle blood flow.

INCENTIVE SPIROMETRY AND BREATHING EXERCISES WERE NOT ABLE TO IMPROVE RESTRICTIVE PULMONARY CHARACTERISTICS INDUCED BY WATER IMMERSION IN HEALTHY SUBJECTS

OpenAIRE

Aline A. Vepo,; Caroline S. Martinez; Giulia A. Wiggers; Franck M. Peçanha

2016-01-01

pulmonary volumes and capacities which could be at least in part similar to that happen in healthy individuals during water immersion. Objectives: To investigate if respiratory effects of water immersion are partially due to enhanced return venous from legs and arms and if physiotherapeutic techniques incentive spirometry (IS) and breathing exercises (BE) are able to improve pulmonary volumes and capacities in healthy subjects during water immersion. Design: Randomised, within-partici...

Personal protective clothing against accidental immersion

Energy Technology Data Exchange (ETDEWEB)

Elliott, David; Tipton, Michael [Surrey Univ., Robens Inst. of Health and Safety, Guildford (United Kingdom)

1997-12-31

The requirements for protective clothing against accidental immersion are discussed and the advantages and limitations of the main types of immersion protection available are analysed. The variety of designs available reflects the various circumstances under which they may be used. In broad terms in the offshore industry these include the following activities: normal work without risk of immersion but with a possible need to abandon the rig or ship; work in areas where there is risk of accidentally falling into the sea; flying over the sea in a helicopter. The first response to sudden immersion in sea water, which must usually be considered to be cold, is a sudden gasp often followed by an immediate phase of uncontrolled breathing. Since control of ones breathing between and under the breaking waves is essential to staying alive, this is a critical time. After surviving this initial ``cold shock`` phase, the effects of body heat loss become hazardous. Protection against hypothermia has been the priority for those providing survival suits and protective clothing while the hazard of the immediate response to cold immersion has been unrecognised to a large extent. (UK)

Critical experiments simulating accidental water immersion of highly enriched uranium dioxide fuel elements

International Nuclear Information System (INIS)

Ponomarev-Stepnoi, N.N.; Glushkov, L.S.

2003-01-01

The paper focuses on experimental analysis of nuclear criticality safety at accidental water immersion of fuel elements of the Russian TOPAZ-2 space nuclear power system reactor. The structure of water-moderated heterogeneous critical assemblies at the NARCISS facility is described in detail, including sizes, compositions, densities of materials of the main assembly components for various core configurations. Critical parameters of the assemblies measured for varying number of fuel elements, height of fuel material in fuel elements and their arrangement in the water moderator with a uniform or variable spacing are presented. It has been found from the experiments that at accidental water immersion of fuel elements involved, the minimum critical mass equal to approximately 20 kg of uranium dioxide is achieved at 31-37 fuel elements. The paper gives an example of a physical model of the water-moderated heterogeneous critical assembly with a detailed characterization of its main components that can be used for calculations using different neutronic codes, including Monte Carlo ones. (author)

Immersion-scanning-tunneling-microscope for long-term variable-temperature experiments at liquid-solid interfaces

Science.gov (United States)

Ochs, Oliver; Heckl, Wolfgang M.; Lackinger, Markus

2018-05-01

Fundamental insights into the kinetics and thermodynamics of supramolecular self-assembly on surfaces are uniquely gained by variable-temperature high-resolution Scanning-Tunneling-Microscopy (STM). Conventionally, these experiments are performed with standard ambient microscopes extended with heatable sample stages for local heating. However, unavoidable solvent evaporation sets a technical limit on the duration of these experiments, hence prohibiting long-term experiments. These, however, would be highly desirable to provide enough time for temperature stabilization and settling of drift but also to study processes with inherently slow kinetics. To overcome this dilemma, we propose a STM that can operate fully immersed in solution. The instrument is mounted onto the lid of a hermetically sealed heatable container that is filled with the respective solution. By closing the container, both the sample and microscope are immersed in solution. Thereby solvent evaporation is eliminated and an environment for long-term experiments with utmost stable and controllable temperatures between room-temperature and 100 °C is provided. Important experimental requirements for the immersion-STM and resulting design criteria are discussed, the strategy for protection against corrosive media is described, the temperature stability and drift behavior are thoroughly characterized, and first long-term high resolution experiments at liquid-solid interfaces are presented.

Postexercise cold water immersion modulates skeletal muscle PGC-1α mRNA expression in immersed and nonimmersed limbs: evidence of systemic regulation.

Science.gov (United States)

Allan, Robert; Sharples, Adam P; Close, Graeme L; Drust, Barry; Shepherd, Sam O; Dutton, John; Morton, James P; Gregson, Warren

2017-08-01

Mechanisms mediating postexercise cold-induced increases in PGC-1α gene expression in human skeletal muscle are yet to be fully elucidated but may involve local cooling effects on AMPK and p38 MAPK-related signaling and/or increased systemic β-adrenergic stimulation. Therefore, we aimed to examine whether postexercise cold water immersion enhancement of PGC-1α mRNA is mediated through local or systemic mechanisms. Ten subjects completed acute cycling (8 × 5 min at ~80% peak power output) followed by seated-rest (CON) or single-leg cold water immersion (CWI; 10 min, 8°C). Muscle biopsies were obtained preexercise, postexercise, and 3 h postexercise from a single limb in the CON condition but from both limbs in CWI [thereby providing tissue from a CWI and nonimmersed limb (NOT)]. Muscle temperature decreased up to 2 h postexercise following CWI (-5°C) in the immersed limb, with lesser changes observed in CON and NOT (-3°C, P cold induction of PGC-1α mRNA. NEW & NOTEWORTHY We report for the first time that postexercise cold water immersion of one limb also enhances PGC-1α expression in a contralateral, nonimmersed limb. We suggest that increased systemic β-adrenergic stimulation, and not localized cooling per se, exerts regulatory effects on local signaling cascades, thereby modulating PGC-1α expression. Therefore, these data have important implications for research designs that adopt contralateral, nonimmersed limbs as a control condition while also increasing our understanding of the potential mechanisms underpinning cold-mediated PGC-1α responses. Copyright © 2017 the American Physiological Society.

Cold-Water Immersion for Hyperthermic Humans Wearing American Football Uniforms.

Science.gov (United States)

Miller, Kevin C; Swartz, Erik E; Long, Blaine C

2015-08-01

Current treatment recommendations for American football players with exertional heatstroke are to remove clothing and equipment and immerse the body in cold water. It is unknown if wearing a full American football uniform during cold-water immersion (CWI) impairs rectal temperature (Trec) cooling or exacerbates hypothermic afterdrop. To determine the time to cool Trec from 39.5°C to 38.0°C while participants wore a full American football uniform or control uniform during CWI and to determine the uniform's effect on Trec recovery postimmersion. Crossover study. Laboratory. A total of 18 hydrated, physically active, unacclimated men (age = 22 ± 3 years, height = 178.8 ± 6.8 cm, mass = 82.3 ± 12.6 kg, body fat = 13% ± 4%, body surface area = 2.0 ± 0.2 m(2)). Participants wore the control uniform (undergarments, shorts, crew socks, tennis shoes) or full uniform (control plus T-shirt; tennis shoes; jersey; game pants; padding over knees, thighs, and tailbone; helmet; and shoulder pads). They exercised (temperature approximately 40°C, relative humidity approximately 35%) until Trec reached 39.5°C. They removed their T-shirts and shoes and were then immersed in water (approximately 10°C) while wearing each uniform configuration; time to cool Trec to 38.0°C (in minutes) was recorded. We measured Trec (°C) every 5 minutes for 30 minutes after immersion. Time to cool from 39.5°C to 38.0°C and Trec. The Trec cooled to 38.0°C in 6.19 ± 2.02 minutes in full uniform and 8.49 ± 4.78 minutes in control uniform (t17 = -2.1, P = .03; effect size = 0.48) corresponding to cooling rates of 0.28°C·min(-1) ± 0.12°C·min(-1) in full uniform and 0.23°C·min(-1) ± 0.11°C·min(-1) in control uniform (t17 = 1.6, P = .07, effect size = 0.44). The Trec postimmersion recovery did not differ between conditions over time (F1,17 = 0.6, P = .59). We speculate that higher skin temperatures before CWI, less shivering, and greater conductive cooling explained the faster cooling

An Experimental Design Approach for the Analysis of Liquid Phase Products in Water for Hydrogenolysis of Glycerol using Immersed Solid-Phase Micro extraction

International Nuclear Information System (INIS)

Noraini Hamzah; Rozita Osman; Noraini Hamzah; Mohd Ambar Yarmo

2013-01-01

In this study, a response surface methodology (RSM) was applied to optimize the immersed-solid-phase micro extraction (immersed-SPME) conditions for the first time using a polyacrylate (PA) coated fiber. This was to determine liquid phase compounds in water for hydrogenolysis reaction of glycerol. There are a three-factor response surface experimental design was used to evaluate the interactive effects of extraction temperature (30-70 degree Celsius), extraction time (10-30 minutes) and desorption time (2-18 minutes) on the analysis of liquid phase compounds in water for hydrogenolysis of glycerol using immersed-solid-phase micro extraction (immersed-SPME). The extraction conditions using immersed-SPME were optimized in order to achieve high enrichment of the analytes from aqueous samples. The isolated compounds from the SPME fiber were desorbed and separated on a capillary polar column of a gas chromatography-flame ionization detector (GC-FID). The extraction time and desorption time were found significant in increasing the amount of glycerol in aqueous hydrogenolysis of glycerol. Nevertheless, the effect of extraction temperature was not significant. In terms of interactions between the effects, the relation between extraction temperature and extraction time was the most significant. The optimised immersed-SPME conditions were at extraction temperature of 27 degree Celsius, extraction time of 30 minutes and 15 minutes of desorption time. Thus, the application of SPME was found to be a rapid and effective technique in the determination of glycerol and propylene glycol compounds in aqueous hydrogenolysis glycerol. (author)

Survey of public knowledge and responses to educational slogans regarding cold-water immersion.

Science.gov (United States)

Giesbrecht, Gordon G; Pretorius, Thea

2008-01-01

Cold water temperature is a significant factor in North American drownings. These deaths are usually attributed to hypothermia. Survey questions were administered to 661 attendees of cold-stress seminars-including medical, rescue, law enforcement and lay attendees-to determine general knowledge of the effects of ice water immersion and responses to 2 public service educational slogans. Five questions were posed at the beginning of seminars to 8 groups (ranging in size from 46 to 195) during a 2-year period. Pi(2) analyses were used to determine if responses within any occupational category differed from the group responses. A high portion of respondents greatly underestimated the time to become hypothermic in ice water (correct answer >30 minutes; 84% stated 15 minutes or less) and the time until cooling was life threatening (correct answer >60 minutes; 85% stated 30 minutes or less). There were no occupational differences in these responses. Most of the respondents identified a correct cause of death during cold stress (81% stated cardiac arrest, hypothermia, or drowning). Although both educational slogans had some advantages, between 40% (Slogan #1) to 50% (Slogan #2) of respondents did not respond correctly. The majority of respondents underestimated the time available for survival during ice water immersion. It is important to educate the public accurately to decrease the probability of panic under these circumstances. More work is required to develop effective educational slogans that provide proper information and actions for victims of cold-water immersion.

Observations on biofilm bacteria isolated from aluminium panels immersed in estuarine waters

Digital Repository Service at National Institute of Oceanography (India)

Sonak, S.; Bhosle, N.B.

Microfouling biomass generally increased on aluminium panels immersed in the surface waters of a tropical estuary over a period of 30 d. A hundred bacterial colonies were randomly isolated, purified and morphologically, physiologically...

Can Temperate-Water Immersion Effectively Reduce Rectal Temperature in Exertional Heat Stroke? A Critically Appraised Topic.

Science.gov (United States)

Truxton, Tyler T; Miller, Kevin C

2017-09-01

Clinical Scenario: Exertional heat stroke (EHS) is a medical emergency which, if left untreated, can result in death. The standard of care for EHS patients includes confirmation of hyperthermia via rectal temperature (T rec ) and then immediate cold-water immersion (CWI). While CWI is the fastest way to reduce T rec , it may be difficult to lower and maintain water bath temperature in the recommended ranges (1.7°C-15°C [35°F-59°F]) because of limited access to ice and/or the bath being exposed to high ambient temperatures for long periods of time. Determining if T rec cooling rates are acceptable (ie, >0.08°C/min) when significantly hyperthermic humans are immersed in temperate water (ie, ≥20°C [68°F]) has applications for how EHS patients are treated in the field. Are T rec cooling rates acceptable (≥0.08°C/min) when significantly hyperthermic humans are immersed in temperate water? T rec cooling rates of hyperthermic humans immersed in temperate water (≥20°C [68°F]) ranged from 0.06°C/min to 0.19°C/min. The average T rec cooling rate for all examined studies was 0.11±0.06°C/min. Clinical Bottom Line: Temperature water immersion (TWI) provides acceptable (ie, >0.08°C/min) T rec cooling rates for hyperthermic humans post-exercise. However, CWI cooling rates are higher and should be used if feasible (eg, access to ice, shaded treatment areas). Strength of Recommendation: The majority of evidence (eg, Level 2 studies with PEDro scores ≥5) suggests TWI provides acceptable, though not ideal, T rec cooling. If possible, CWI should be used instead of TWI in EHS scenarios.

Effects of menthol application on the skin during prolonged immersion in cool and cold water.

Science.gov (United States)

Botonis, P G; Kounalakis, S N; Cherouveim, E D; Koskolou, M D; Geladas, N D

2018-03-01

The aim of the study was to compare the effect of skin surface menthol application on rectal temperature (Tre) during prolonged immersion in cool and cold water. We hypothesized that menthol application would lead to a slower Tre decline due to the reduced heat loss as a consequence of the menthol-induced vasoconstriction and that this effect would be attenuated during cold-water immersion. Six male subjects were immersed for 55 minutes in stirred cool (24°C) or cold (14°C) water immediately after attaining a Tre of 38°C by cycling at 60% of maximum heart rate on two occasions: without (ΝM) and with (M) whole-body skin application of menthol cream. Tre, the proximal-distal skin temperature gradient, and oxygen uptake were continuously measured. ANOVA with repeated measures was employed to detect differences among variables. Significance level was set at 0.05. The area under the curve for Tre was calculated and was greater in 24°C M (-1.81 ± 8.22 a.u) compared to 24°C NM (-27.09 ± 19.09 a.u., P = .03, r = .90), 14°C NM (-18.08 ± 10.85 a.u., P = .03, r = .90), and 14°C M (-11.71 ± 12.58 a.u, P = .05, r = .81). In cool water, oxygen uptake and local vasoconstriction were increased (P ≤ .05) by 39 ± 25% and 56 ± 37%, respectively, with menthol compared to ΝM, while no differences were observed in cold water. Menthol application on the skin before prolonged immersion reduces heat loss resulting in a blunted Tre decline. However, such a response is less obvious at 14°C water immersion, possibly because high-threshold cold-sensitive fibers are already maximally recruited and the majority of cold receptors saturated. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Facial immersion in cold water enhances cerebral blood velocity during breath-hold exercise in humans.

Science.gov (United States)

Kjeld, Thomas; Pott, Frank C; Secher, Niels H

2009-04-01

The diving response is initiated by apnea and facial immersion in cold water and includes, besides bradycardia, peripheral vasoconstriction, while cerebral perfusion may be enhanced. This study evaluated whether facial immersion in 10 degrees C water has an independent influence on cerebral perfusion evaluated as the middle cerebral artery mean flow velocity (MCA V(mean)) during exercise in nine male subjects. At rest, a breath hold of maximum duration increased the arterial carbon dioxide tension (Pa(CO(2))) from 4.2 to 6.7 kPa and MCA V(mean) from 37 to 103 cm/s (mean; approximately 178%; P breath hold increased Pa(CO(2)) from 5.9 to 8.2 kPa (P breath hold diverts blood toward the brain with a >100% increase in MCA V(mean), largely because Pa(CO(2)) increases, but the increase in MCA V(mean) becomes larger when combined with facial immersion in cold water independent of Pa(CO(2)).

Effects of water immersion to the neck on pulmonary circulation and tissue volume in man

Science.gov (United States)

Begin, R.; Epstein, M.; Sackner, M. A.; Levinson, R.; Dougherty, R.; Duncan, D.

1976-01-01

A rapid noninvasive breathing method is used to obtain serial measurements of the pulmonary capillary blood flow, diffusing capacity per unit of alveolar volume, combined pulmonary tissue plus capillary volume, functional residual capacity, and oxygen consumption in five normal subjects undergoing 6 h of sitting, 4 h of sitting while immersed to the neck in thermoneutral water, and 4 h of lying in thermoneutral water to the neck. The rebreathing method employed a test gas mixture containing 0.5% C2H2, 0.3% C(18)O, 10% He, 21% O2, and balance N2. It is shown that immersion to the neck in the seated posture results in significant increases in sodium excretion cardiac output, and diffusing capacity per unit of alveolar volume. The pulmonary tissue plus capillary volume did not change, demonstrating that the central vascular engorgement induced by water immersion is not accompanied by significant extravasation of fluid into the pulmonary interstitial space.

Cold-water immersion alters muscle recruitment and balance of basketball players during vertical jump landing.

Science.gov (United States)

Macedo, Christiane de Souza Guerino; Vicente, Rafael Chagas; Cesário, Mauricio Donini; Guirro, Rinaldo Roberto de Jesus

2016-01-01

The purpose of this study was to evaluate the effects of cold-water immersion on the electromyographic (EMG) response of the lower limb and balance during unipodal jump landing. The evaluation comprised 40 individuals (20 basketball players and 20 non-athletes). The EMG response in the lateral gastrocnemius, tibialis anterior, fibular longus, rectus femoris, hamstring and gluteus medius; amplitude and mean speed of the centre of pressure, flight time and ground reaction force (GRF) were analysed. All volunteers remained for 20 min with their ankle immersed in cold-water, and were re-evaluated immediately post and after 10, 20 and 30 min of reheating. The Shapiro-Wilk test, Friedman test and Dunn's post test (P lower for the athletes. Lower jump flight time and GRF, greater amplitude and mean speed of centre of pressure were predominant in the athletes. Cold-water immersion decreased the EMG activity of the lower limb, flight time and GRF and increased the amplitude and mean speed of centre of pressure.

Pre-treatment with mild whole-body heating prevents gastric ulcer induced by restraint and water-immersion stress in rats.

Science.gov (United States)

Itoh, Y H; Noguchi, R

2000-01-01

The purpose of this study was to assess the preventive effect of pre-mild whole-body heating (WBH) on gastric ulcer induced by restraint and water-immersion stress. The ulcer index and ulcer area ratio in rats exposed to restraint and water-immersion stress were significantly decreased (p immersion stress alone (p immersion, thereby preventing gastric ulcer formation. Pre-treatment with mild WBH is the safest cytoprotective method through the accumulation of HSP 70f. The concentration of HSP 70f in peripheral lymphocytes may be a useful clinical laboratory indicator for assessing the level of HSP 70f as having cytoprotective activity.

Change in muzzle velocity due to freezing and water immersion of .22, long rifle, K.F. cartridges.

Science.gov (United States)

Jauhari, M; Chatterjee, S M; Ghosh, P K

1975-01-01

A study of change in muzzle velocity due to freezing and water immersion of .22, long rifle, K. F. cartridges has been presented. A statistical criterion has been formulated to ascertain whether or not a cartridge undergoes a change in muzzle velocity due to a particular treatment. The muzzle velocity data of .22, long rifle, K. F. cartridges, obtained by an electronic timer before and after the various treatments, have been analyzed in the light of this criterion. These cartridges have generally been found to suffer considerable loss in muzzle velocity when immersed in water for three weeks and also when immersed in water for three days and simultaneously cooled to 0 degrees C. The forensic significance of this loss in muzzle velocity has been discussed.

Lack of diurnal effects on periodic exercise during prolonged cold water immersion.

Science.gov (United States)

Doubt, T J; Smith, D J

1990-03-01

Diurnal effects on periodic exercise were examined in 8 male divers wearing passive thermal protection during whole body immersions in 5 degrees C water for periods of up to 6 h. Studies were done during the course of 5-day air saturation dives at a depth of 1.61 ATA, with immersions beginning at 1000 h (AM) and 2200 h (PM). During each hour of immersion, leg exercise was done for 3 min each at workloads of 50, 70, and 90 W. Heart rate (HR) at each workload increased uniformly with immersion time, without a change in slope of HR vs. workload. No AM or PM differences occurred. AM resting VO2 increased linearly, and to the same extent as PM, with exposure time. VO2 at 50 W also increased at the same rate as resting values. VO2 at 70 and 90 W were similar for AM and PM and did not vary significantly during the 6-h immersions. Temporal increases in exercise HR may reflect cardiac compensation of diminished plasma volume. Workloads greater than or equal to 70 W generate enough metabolic heat in this specific condition to meet the thermogenic requirement. Lack of diurnal effects on exercise variables may be due to environmental conditions suppressing circadian rhythms.

Cardiovascular autonomic control during short-term thermoneutral and cool head-out immersion.

Science.gov (United States)

Mourot, Laurent; Bouhaddi, Malika; Gandelin, Emmanuel; Cappelle, Sylvie; Dumoulin, Gilles; Wolf, Jean-Pierre; Rouillon, Jean Denis; Regnard, Jacques

2008-01-01

Moderately cold head-out water immersion stimulates both baro- and cold-receptors, and triggers complex and contradictory effects on the cardiovascular system and its autonomic nervous control. To assess the effects of water immersion and cold on cardiovascular status and related autonomic nervous activity. Hemodynamic variables and indexes of autonomic nervous activity (analysis of heart rate and blood pressure variability) were evaluated in 12 healthy subjects during 3 exposures of 20 min each in the upright position, i.e., in air (AIR, 24-25 degrees C), and during head-out water immersion at 35-36 degrees C (WIn) and 26-27 degrees C (WIc). Plasma noradrenaline, systolic and diastolic blood pressure, and total peripheral resistances were reduced during WIn compared to AIR (263.9 +/- 39.4 vs. 492.5 +/- 35.7 pg x ml(-1), 116.5 +/- 3.7 and 65.4 +/- 1.7 mmHg vs. 140.8 +/- 4.7 and 89.8 +/- 2.8 mmHg, 14.1 +/- 1.0 vs. 16.3 +/- 0.9 mmHg x L(-1) x min, respectively) while they were increased during WIc (530.8 +/- 84.7 pg ml(-1), 148.0 +/- 7.0 mmHg, 80.8 +/- 3.0 mmHg, and 25.8 +/- 1.9 mmHg x L(-1) x min, respectively). The blood pressure variability was reduced to the same extent during WIc and Win compared to AIR. Heart rate decreased during WIn (67.8 +/- 2.7 vs. 81.2 +/- 2.7 bpm during AIR), in parallel with an increased cardiac parasympathetic activity. This pattern was strengthened during WIc (55.3 +/- 2.2 bpm). Thermoneutral WI lowered sympathetic activity and arterial tone, while moderate whole-body skin cooling triggered vascular sympathetic activation. Conversely, both WI and cold triggered cardiac parasympathetic activation, highlighting a complex autonomic control of the cardiovascular system.

Angiotensin II attenuates the natriuresis of water immersion in humans

DEFF Research Database (Denmark)

Schou, Morten; Gabrielsen, Anders; Bruun, Niels Eske

2002-01-01

The hypothesis was tested that suppression of generation of ANG II is one of the mechanisms of the water immersion (WI)-induced natriuresis in humans. In one protocol, eight healthy young males were subjected to 3 h of 1) WI (WI + placebo), 2) WI combined with ANG II infusion of 0.5 ng. kg(-1). min...

Temperate-Water Immersion as a Treatment for Hyperthermic Humans Wearing American Football Uniforms.

Science.gov (United States)

Miller, Kevin C; Truxton, Tyler; Long, Blaine

2017-08-01

  Cold-water immersion (CWI; 10°C) can effectively reduce body core temperature even if a hyperthermic human is wearing a full American football uniform (PADS) during treatment. Temperate-water immersion (TWI; 21°C) may be an effective alternative to CWI if resources for the latter (eg, ice) are unavailable.   To measure rectal temperature (T rec ) cooling rates, thermal sensation, and Environmental Symptoms Questionnaire (ESQ) scores of participants wearing PADS or shorts, undergarments, and socks (NO pads ) before, during, and after TWI.   Crossover study.   Laboratory.   Thirteen physically active, unacclimatized men (age = 22 ± 2 years, height = 182.3 ± 5.2 cm, mass = 82.5 ± 13.4 kg, body fat = 10% ± 4%, body surface area = 2.04 ± 0.16 m 2 ).   Participants exercised in the heat (40°C, 50% relative humidity) on 2 days while wearing PADS until T rec reached 39.5°C. Participants then underwent TWI while wearing either NO pads or PADS until T rec reached 38°C. Thermal sensation and ESQ responses were collected at various times before and after exercise.   Temperate-water immersion duration (minutes), T rec cooling rates (°C/min), thermal sensation, and ESQ scores.   Participants had similar exercise times (NO pads = 38.1 ± 8.1 minutes, PADS = 38.1 ± 8.5 minutes), hypohydration levels (NO pads = 1.1% ± 0.2%, PADS = 1.2% ± 0.2%), and thermal sensation ratings (NO pads = 7.1 ± 0.4, PADS = 7.3 ± 0.4) before TWI. Rectal temperature cooling rates were similar between conditions (NO pads = 0.12°C/min ± 0.05°C/min, PADS = 0.13°C/min ± 0.05°C/min; t 12 = 0.82, P = .79). Thermal sensation and ESQ scores were unremarkable between conditions over time.   Temperate-water immersion produced acceptable (ie, >0.08°C/min), though not ideal, cooling rates regardless of whether PADS or NO pads were worn. If a football uniform is difficult to remove or the patient is noncompliant, clinicians should begin water-immersion treatment with the

Acute Anxiety Predicts Components of the Cold Shock Response on Cold Water Immersion: Toward an Integrated Psychophysiological Model of Acute Cold Water Survival

Science.gov (United States)

Barwood, Martin J.; Corbett, Jo; Massey, Heather; McMorris, Terry; Tipton, Mike; Wagstaff, Christopher R. D.

2018-01-01

Introduction: Drowning is a leading cause of accidental death. In cold-water, sudden skin cooling triggers the life-threatening cold shock response (CSR). The CSR comprises tachycardia, peripheral vasoconstriction, hypertension, inspiratory gasp, and hyperventilation with the hyperventilatory component inducing hypocapnia and increasing risk of aspirating water to the lungs. Some CSR components can be reduced by habituation (i.e., reduced response to stimulus of same magnitude) induced by 3–5 short cold-water immersions (CWI). However, high levels of acute anxiety, a plausible emotion on CWI: magnifies the CSR in unhabituated participants, reverses habituated components of the CSR and prevents/delays habituation when high levels of anxiety are experienced concurrent to immersions suggesting anxiety is integral to the CSR. Purpose: To examine the predictive relationship that prior ratings of acute anxiety have with the CSR. Secondly, to examine whether anxiety ratings correlated with components of the CSR during immersion before and after induction of habituation. Methods: Forty-eight unhabituated participants completed one (CON1) 7-min immersion in to cold water (15°C). Of that cohort, twenty-five completed four further CWIs that would ordinarily induce CSR habituation. They then completed two counter-balanced immersions where anxiety levels were increased (CWI-ANX) or were not manipulated (CON2). Acute anxiety and the cardiorespiratory responses (cardiac frequency [fc], respiratory frequency [fR], tidal volume [VT], minute ventilation [E]) were measured. Multiple regression was used to identify components of the CSR from the most life-threatening period of immersion (1st minute) predicted by the anxiety rating prior to immersion. Relationships between anxiety rating and CSR components during immersion were assessed by correlation. Results: Anxiety rating predicted the fc component of the CSR in unhabituated participants (CON1; p anxiety rating predicted the f

Acute Anxiety Predicts Components of the Cold Shock Response on Cold Water Immersion: Toward an Integrated Psychophysiological Model of Acute Cold Water Survival.

Science.gov (United States)

Barwood, Martin J; Corbett, Jo; Massey, Heather; McMorris, Terry; Tipton, Mike; Wagstaff, Christopher R D

2018-01-01

Introduction: Drowning is a leading cause of accidental death. In cold-water, sudden skin cooling triggers the life-threatening cold shock response (CSR). The CSR comprises tachycardia, peripheral vasoconstriction, hypertension, inspiratory gasp, and hyperventilation with the hyperventilatory component inducing hypocapnia and increasing risk of aspirating water to the lungs. Some CSR components can be reduced by habituation (i.e., reduced response to stimulus of same magnitude) induced by 3-5 short cold-water immersions (CWI). However, high levels of acute anxiety, a plausible emotion on CWI: magnifies the CSR in unhabituated participants, reverses habituated components of the CSR and prevents/delays habituation when high levels of anxiety are experienced concurrent to immersions suggesting anxiety is integral to the CSR. Purpose: To examine the predictive relationship that prior ratings of acute anxiety have with the CSR. Secondly, to examine whether anxiety ratings correlated with components of the CSR during immersion before and after induction of habituation. Methods: Forty-eight unhabituated participants completed one (CON1) 7-min immersion in to cold water (15°C). Of that cohort, twenty-five completed four further CWIs that would ordinarily induce CSR habituation. They then completed two counter-balanced immersions where anxiety levels were increased (CWI-ANX) or were not manipulated (CON2). Acute anxiety and the cardiorespiratory responses (cardiac frequency [ f c ], respiratory frequency [ f R ], tidal volume [ V T ], minute ventilation [ E ]) were measured. Multiple regression was used to identify components of the CSR from the most life-threatening period of immersion (1 st minute) predicted by the anxiety rating prior to immersion. Relationships between anxiety rating and CSR components during immersion were assessed by correlation. Results: Anxiety rating predicted the f c component of the CSR in unhabituated participants (CON1; p CSR when anxiety

Passive heat exposure induced by hot water leg immersion increased oxyhemoglobin in pre-frontal cortex to preserve oxygenation and did not contribute to impaired cognitive functioning

Science.gov (United States)

Wijayanto, Titis; Toramoto, Sayo; Tochihara, Yutaka

2013-07-01

This study investigated the effects of passive heat exposure on pre-frontal cortex oxygenation and cognitive functioning, specifically to examine whether the change in pre-frontal cortex oxygenation coincided with cognitive functioning during heat exposure. Eleven male students who participated in this study immersed their lower legs to the knees in three different water temperatures, 38 °C, 40 °C, and 42 °C water in an air temperature of 28 º C and 50 % relative humidity for 60 min. After 45 min of leg immersion they performed cognitive functioning tasks assessing their short-term memory while immersing their lower legs. There were higher rectal temperature ( P 0.05). No statistical difference in cognitive functioning among the three conditions was observed with a higher increase of oxyhemoglobin during the cognitive functioning in the 42 °C condition for the left ( P = 0.05) and right ( P thermally comfortable.

Studies of acid-base homeostasis during simulated weightlessness: Application of the water immersion model to man

Science.gov (United States)

Epstein, M.

1975-01-01

The effects of water immersion on acid-base homeostasis were investigated under carefully controlled conditions. Studies of renal acidification were carried out on seven healthy male subjects, each consuming a diet containing 150 meq sodium and 100 meq potassium. Control and immersion studies were carried out on each subject on the fourth and sixth days, respectively, of dietary equilibration, by which time all subjects had achieved sodium balance. The experimental protocols on study days were similar (except for the amount of water administered).

The effect of γ-ray irradiation on the water immersion and electricity application deterioration of polyethylene

International Nuclear Information System (INIS)

Higashimura, Yutaka; Fujioka, Norihide; Karino, Yasushi; Onuki, Tsutomu; Watanabe, Kiyoshi.

1984-01-01

Two types of polyethylene, that is, standard low density cross-linked polyethylene (XLPE-A) and the same with the addition of a polymer having ester radicals (XLPE-B), were used for this experiment. The water immersion and electricity application test was carried out 1) simultaneously with γ-ray irradiation, 2) after γ-ray irradiation, and 3) without γ-ray irradiation. It was found that 1) the water-immersion and electricity-application life of XLPE-A was rather elongated by γ-ray irradiation, 2) the water-immersion and electricity-application life of XLPE-B was shortened by γ-ray irradiation, which is probably attributable to the bond-rupture of ester radicals of the added polymer, 3) the life, when the irradiation of γ-ray and the application of electricity in water were simultaneously exerted, agreed well with the empirical equation which is derived on the assumption that the life is decreased proportionally to the overall dose of γ-ray, and 4) even when polyethylene was irradiated with γ-ray in hot water, the properties of polyethylene was estimated to deteriorate in the same extent as in the air. (Yoshitake, I.)

Investigation on degradation mechanism of ion exchange membrane immersed in highly concentrated tritiated water under the Broader Approach Activities

Energy Technology Data Exchange (ETDEWEB)

Iwai, Yasunori, E-mail: iwai.yasunori@jaea.go.jp; Sato, Katsumi; Yamanishi, Toshihiko

2014-10-15

Highlights: • Endurance of Nafion ion exchange membrane immersed into 1.38 × 10{sup 12} Bq/kg of highly concentrated tritiated water has been demonstrated. • The formation of free hydrophobic free products by reactions between radicals on the membrane and oxygen caused the decrease in ionic conductivity. • From the {sup 19}F NMR spectrum, no distinctive degradation in the membrane structure by interaction with tritium was measured. - Abstract: The ion exchange membrane is a key material for electrolysis cells of the water detritiation system. Durability of ion exchange membrane has been demonstrated under the Broader Approach Activities. Long-term exposure of Nafion{sup ®} ion exchange membrane in 1.38 × 10{sup 12} Bq/kg of tritiated water was conducted at room temperature for up to 2 years. The ionic conductivity of Nafion{sup ®} membrane after immersed in tritiated water was changed. The change in color of membrane from colorless to yellowish was caused by reactions of radicals on the polymer and oxygen molecules in air. Infrared Fourier transform spectrum of a yellowish membrane revealed a small peak for bending vibration of C-H situated at 1437 cm{sup −1}, demonstrating the formation of hydrophobic functional group in the membrane. The hydrophilic network in Nafion{sup ®} membrane was partially obstructed by the hydrophobic free products. This caused the decrease in ionic conductivity. The peak for bending vibration was clearly eliminated in the spectrum of the membrane after treatment by acid for removal of free products. The high-resolution solid state {sup 19}F NMR spectrum of a membrane after immersed in tritiated water was similar to that of a membrane irradiated with gamma-rays. From the {sup 19}F NMR spectrum, no distinctive degradation in the membrane structure by interaction with tritium was measured.

Investigation on degradation mechanism of ion exchange membrane immersed in highly concentrated tritiated water under the Broader Approach Activities

International Nuclear Information System (INIS)

Iwai, Yasunori; Sato, Katsumi; Yamanishi, Toshihiko

2014-01-01

Highlights: • Endurance of Nafion ion exchange membrane immersed into 1.38 × 10 12 Bq/kg of highly concentrated tritiated water has been demonstrated. • The formation of free hydrophobic free products by reactions between radicals on the membrane and oxygen caused the decrease in ionic conductivity. • From the 19 F NMR spectrum, no distinctive degradation in the membrane structure by interaction with tritium was measured. - Abstract: The ion exchange membrane is a key material for electrolysis cells of the water detritiation system. Durability of ion exchange membrane has been demonstrated under the Broader Approach Activities. Long-term exposure of Nafion ® ion exchange membrane in 1.38 × 10 12 Bq/kg of tritiated water was conducted at room temperature for up to 2 years. The ionic conductivity of Nafion ® membrane after immersed in tritiated water was changed. The change in color of membrane from colorless to yellowish was caused by reactions of radicals on the polymer and oxygen molecules in air. Infrared Fourier transform spectrum of a yellowish membrane revealed a small peak for bending vibration of C-H situated at 1437 cm −1 , demonstrating the formation of hydrophobic functional group in the membrane. The hydrophilic network in Nafion ® membrane was partially obstructed by the hydrophobic free products. This caused the decrease in ionic conductivity. The peak for bending vibration was clearly eliminated in the spectrum of the membrane after treatment by acid for removal of free products. The high-resolution solid state 19 F NMR spectrum of a membrane after immersed in tritiated water was similar to that of a membrane irradiated with gamma-rays. From the 19 F NMR spectrum, no distinctive degradation in the membrane structure by interaction with tritium was measured

Three dimensional changes in maxillary complete dentures immersed in water for seven days after polymerization

Directory of Open Access Journals (Sweden)

Shinsuke Sadamori

2008-03-01

Full Text Available The purpose of this study was to investigate the three dimensional changes in the fitting surface and artificial teeth of maxillary complete dentures which were fabricated using two different polymerizing processes: heat polymerization (HP and microwave polymerization (MP, after immersion in water for seven days. The amount of distortion in the molar region of the alveolar ridge was significantly different between HP and MP. However, the overall distortion of the dentures polymerized using both methods was similar. The distortion due to immersion in water for seven days compensated for the polymerization distortion, but the amount of distortion was very slight.

Three dimensional live-cell STED microscopy at increased depth using a water immersion objective

Science.gov (United States)

Heine, Jörn; Wurm, Christian A.; Keller-Findeisen, Jan; Schönle, Andreas; Harke, Benjamin; Reuss, Matthias; Winter, Franziska R.; Donnert, Gerald

2018-05-01

Modern fluorescence superresolution microscopes are capable of imaging living cells on the nanometer scale. One of those techniques is stimulated emission depletion (STED) which increases the microscope's resolution many times in the lateral and the axial directions. To achieve these high resolutions not only close to the coverslip but also at greater depths, the choice of objective becomes crucial. Oil immersion objectives have frequently been used for STED imaging since their high numerical aperture (NA) leads to high spatial resolutions. But during live-cell imaging, especially at great penetration depths, these objectives have a distinct disadvantage. The refractive index mismatch between the immersion oil and the usually aqueous embedding media of living specimens results in unwanted spherical aberrations. These aberrations distort the point spread functions (PSFs). Notably, during z- and 3D-STED imaging, the resolution increase along the optical axis is majorly hampered if at all possible. To overcome this limitation, we here use a water immersion objective in combination with a spatial light modulator for z-STED measurements of living samples at great depths. This compact design allows for switching between objectives without having to adapt the STED beam path and enables on the fly alterations of the STED PSF to correct for aberrations. Furthermore, we derive the influence of the NA on the axial STED resolution theoretically and experimentally. We show under live-cell imaging conditions that a water immersion objective leads to far superior results than an oil immersion objective at penetration depths of 5-180 μm.

Immersion Revisited: A Review of Existing Definitions of Immersion and Their Relation to Different Theories of Presence

Directory of Open Access Journals (Sweden)

Niels Christian Nilsson

2016-11-01

Full Text Available The term immersion continues to be applied inconsistently within and across different fields of research connected with the study of virtual reality and interactive media. Moreover, immersion is oftentimes used interchangeably with the terms presence and engagement. This article details a review of existing definitions of immersion originating within the study of video games, virtual environments, and literary works of fiction. Based on this review, a three-dimensional taxonomy of the various conceptualizations of immersion is proposed. That is, the existing definitions of immersion may be broadly divided into three categories, each representing a dimension of the taxonomy: immersion as a property of a system, a subjective response to narrative contents, or a subjective response to challenges within the virtual environment. Finally, four distinct theories of presence are introduced and, based on the established taxonomy, we discuss how the individual theories relate to existing definitions of immersion.

Performance comparison between ethanol phase-change immersion and active water cooling for solar cells in high concentrating photovoltaic system

International Nuclear Information System (INIS)

Wang, Yiping; Wen, Chen; Huang, Qunwu; Kang, Xue; Chen, Miao; Wang, Huilin

2017-01-01

Highlights: • Thermal performances of ethanol phase-change immersion and active water cooling are compared. • Effects of operation parameters on ethanol phase-change immersion are studied. • Optimum filling ratio is 30% for ethanol phase-change immersion cooling system. • Exergy efficiency of ethanol phase-change immersion method increases by 57%. - Abstract: This paper presents an optimized ethanol phase-change immersion cooling method to obtain lower temperature of dense-array solar cells in high concentrating photovoltaic system. The thermal performances of this system were compared with a conventional active water cooling system with minichannels from the perspectives of start-up characteristic, temperature uniformity, thermal resistance and heat transfer coefficient. This paper also explored the influences of liquid filling ratio, absolute pressure and water flow rate on thermal performances. Dense-array LEDs were used to simulate heat power of solar cells worked under high concentration ratios. It can be observed that the optimal filling ratio was 30% in which the thermal resistance was 0.479 °C/W and the heat transfer coefficient was 9726.21 W/(m 2 ·°C). To quantify the quality of energy output of two cooling systems, exergy analysis are conducted and maximum exergy efficiencies were 17.70% and 11.27%, respectively. The experimental results represent an improvement towards thermal performances of ethanol phase-change immersion cooling system due to the reduction in contact thermal resistance. This study improves the operation control and applications for ethanol phase-change immersion cooling technology.

Ultrafast cooling by covalently bonded graphene-carbon nanotube hybrid immersed in water

DEFF Research Database (Denmark)

Chen, Jie; Walther, Jens Honore; Koumoutsakos, Petros

2016-01-01

, we demonstrate, through transient heat-dissipation simulations, that a covalently bonded graphene-carbon nanotube (G-CNT) hybrid immersed in water is a promising solution for the ultrafast cooling of such high-temperature and high heat-flux surfaces. The G-CNT hybrid offers a unique platform...

Diametral tensile strength of two dental composites when immersed in ethanol, distilled water and artificial saliva.

Science.gov (United States)

Rehman, Abdur; Amin, Faiza; Abbas, Muhammad

2014-11-01

To examine the effect of distilled water, artificial saliva and ethanol on the tensile strength of direct tooth-coloured restorative material. The study was conducted at Dr. Ishrat ul Ebad Khan Institute of Oral Health Sciences, Dow University of Health Sciences (DUHS), Karachi, from April 2011 to September 2012. The testing was performed at the Pakistan Council of Scientific and Industrial Research (PCSIR) laboratories. Two composite resins Filtek Z250 and Spectrum TPH were tested. Specimens (13 mm x 3 mm x 2 mm) of each material were prepared in the stainless steel mould according to the manufacturers' instructions and distributed into 3 equal groups: one immersed in distilled water, the other in artificial saliva, and the last one in ethanol for 24 hours. Tensile strength was determined after 24 hours in universal Instron Testing Machine. There were 72 specimens in all; 36 (50%) each for Filtek Z250 and Spectrum TPH. The three sub-groups in each case had 12 (33.3%) specimens. For the Filtek Z250, there was no statistically significant difference between immersion in distilled water and artificial saliva, but the ethanol group presented lower tensile strength (ptensile strength compared to distilled water (ptested composite resins were affected by the immersion media and adversely affected the mechanical properties of composite resins.

Lower-limb hot-water immersion acutely induces beneficial hemodynamic and cardiovascular responses in peripheral arterial disease and healthy, elderly controls.

Science.gov (United States)

Thomas, Kate N; van Rij, André M; Lucas, Samuel J E; Cotter, James D

2017-03-01

Passive heat induces beneficial perfusion profiles, provides substantive cardiovascular strain, and reduces blood pressure, thereby holding potential for healthy and cardiovascular disease populations. The aim of this study was to assess acute responses to passive heat via lower-limb, hot-water immersion in patients with peripheral arterial disease (PAD) and healthy, elderly controls. Eleven patients with PAD (age 71 ± 6 yr, 7 male, 4 female) and 10 controls (age 72 ± 7 yr, 8 male, 2 female) underwent hot-water immersion (30-min waist-level immersion in 42.1 ± 0.6°C water). Before, during, and following immersion, brachial and popliteal artery diameter, blood flow, and shear stress were assessed using duplex ultrasound. Lower-limb perfusion was measured also using venous occlusion plethysmography and near-infrared spectroscopy. During immersion, shear rate increased ( P Lower-limb blood flow increased significantly in both groups, as measured from duplex ultrasound (>200%), plethysmography (>100%), and spectroscopy, while central and peripheral pulse-wave velocity decreased in both groups. Mean arterial blood pressure was reduced by 22 ± 9 mmHg (main effect P lower 3 h afterward. In PAD, popliteal shear profiles and claudication both compared favorably with those measured immediately following symptom-limited walking. A 30-min hot-water immersion is a practical means of delivering heat therapy to PAD patients and healthy, elderly individuals to induce appreciable systemic (chronotropic and blood pressure lowering) and hemodynamic (upper and lower-limb perfusion and shear rate increases) responses. Copyright © 2017 the American Physiological Society.

Demonstration on endurance of ion exchange membrane immersed in high-concentration tritiated water under the Broader Approach Activities

Energy Technology Data Exchange (ETDEWEB)

Iwai, Yasunori, E-mail: iwai.yasunori@jaea.go.jp; Sato, Katsumi; Kawamura, Yoshinori; Yamanishi, Toshihiko

2013-10-15

Highlights: • Endurance of Nafion ion exchange membrane immersed in 1.38 × 10{sup 12} Bq/kg of highly concentrated tritiated water was demonstrated. • Degradation of Nafion backbone structure by tritium beta was similar to that by gamma rays and electron beams at an equivalent dose. • Degradation directly by radiation was dominant at room temperature compared with that by reactions with radicals produced from water radiolysis. -- Abstract: The Nafion{sup ®} ion exchange membrane is a key material for electrolysis cells of the water detritiation system. Endurance of Nafion ion exchange membrane immersed in 1.38 × 10{sup 12} Bq/kg of highly concentrated tritiated water has been demonstrated at room temperature for up to 2 years under the Broader Approach Activities. The curves of percent elongation at break vs. dose and tensile strength vs. dose for the Nafion membranes immersed in tritiated water were well consistent with those for Nafion membranes irradiated to an equivalent dose with gamma rays and electron beams. This shows that the degradation of Nafion backbone structure by tritium beta is similar to that by gamma rays and electron beams. The results of ferric Fenton test indicated that the degradation directly by radiation was dominant at room temperature compared with that by reactions with radicals produced from water radiolysis. The curve of ion exchange capacity vs. dose for the Nafion membranes immersed in tritiated water was also well consistent with that for Nafion membranes irradiated to an equivalent dose with gamma rays and electron beams. These results showed irradiation tests with gamma rays and electron beams were alternative for predicting degradation of ion exchange membrane by tritium beta.

Acute effects of Finnish sauna and cold-water immersion on haemodynamic variables and autonomic nervous system activity in patients with heart failure.

Science.gov (United States)

Radtke, Thomas; Poerschke, Daniel; Wilhelm, Matthias; Trachsel, Lukas D; Tschanz, Hansueli; Matter, Friederike; Jauslin, Daniel; Saner, Hugo; Schmid, Jean-Paul

2016-04-01

The haemodynamic response to Finnish sauna and subsequent cold-water immersion in heart failure patients is unknown. Haemodynamic response to two consecutive Finnish sauna (80℃) exposures, followed by a final head-out cold-water immersion (12℃) was measured in 37 male participants: chronic heart failure (n = 12, 61.8 ± 9.2 years), coronary artery disease (n = 13, 61.2 ± 10.6 years) and control subjects (n = 12, 60.9 ± 8.9 years). Cardiac output was measured non-invasively with an inert gas rebreathing method prior to and immediately after the first sauna exposure and after cold-water immersion, respectively. Blood pressure was measured before, twice during and after sauna. The autonomic nervous system was assessed by power spectral analysis of heart rate variability. Total power, low-frequency and high-frequency components were evaluated. The low frequency/high frequency ratio was used as a marker of sympathovagal balance. Sauna and cold-water immersion were well tolerated by all subjects. Cardiac output and heart rate significantly increased in all groups after sauna and cold-water immersion (p heart failure patients. In coronary artery disease patients and controls a prolonged increase in low frequency/high frequency ratio was observed after the first sauna exposure. Acute exposure to Finnish sauna and cold-water immersion causes haemodynamic alterations in chronic heart failure patients similarly to control subjects and in particular did not provoke an excessive increase in adrenergic activity or complex arrhythmias. © The European Society of Cardiology 2015.

GROWTH RESPONSE OF CLOWN LOACH (Chromobotia macracanthus Bleeker 1852 JUVENILES IMMERSED IN WATER CONTAINING RECOMBINANT GROWTH HORMONE

Directory of Open Access Journals (Sweden)

Asep Permana

2015-12-01

Full Text Available The main problem in the culture of clown loach (Chromobotia macracanthus is the slow growth rate, which takes about six months to reach its market size (two inches total body length. Slow growth eventually cause a long production time and increase the production costs. An alternative solution can be proposed in order to enhance the growth is by using recombinant growth hormone. The aim of this study was to determine the immersion dose of recombinant Epinephelus lanceolatus growth hormone (rElGH which can generate the highest growth in clown loach. Larvae at seven day after hatching were hyperosmotic treated with NaCl 2.0% for one minute, then immersed for one hour in water containing 0.3% NaCl, 0.01% bovine serum albumin (BSA, and different doses of rElGH, namely: 0.12 (treatment A, 1.2 (B, 12 (C, and 120 mg/L (D. As control, fish were immersed in water without rElGH and NaCl (control-1, water containing 0.3% NaCl and 0.01% BSA (control-2, and 0.3% NaCl water (control-3. Each treatment was replicated three times. The results showed that clown loach juveniles in treatment B, C, and D had longer total body length (P0.05. In addition, the percentage of large size juveniles increased approximately 5% in treatment B, almost the same as in the medium size, while the small size were decrease compared to the control-1. Thus, the best immersion dose of rElGH was 1.2 mg/L water.

Study on Surface Permeability of Concrete under Immersion

OpenAIRE

Liu, Jun; Xing, Feng; Dong, Biqin; Ma, Hongyan; Pan, Dong

2014-01-01

In this paper, concrete specimens are immersed in ultrapure water, to study the evolutions of surface permeability, pore structure and paste microstructure following the prolonging of immersion period. According to the results, after 30-day immersion, the surface permeability of concrete becomes higher as compared with the value before immersion. However, further immersion makes the surface permeability decrease, so that the value measured after 150-day immersion is only half that measured af...

A Theory of Immersion Freezing

Science.gov (United States)

Barahona, Donifan

2017-01-01

Immersion freezing is likely involved in the initiation of precipitation and determines to large extent the phase partitioning in convective clouds. Theoretical models commonly used to describe immersion freezing in atmospheric models are based on the classical nucleation theory which however neglects important interactions near the immersed particle that may affect nucleation rates. This work introduces a new theory of immersion freezing based on two premises. First, immersion ice nucleation is mediated by the modification of the properties of water near the particle-liquid interface, rather than by the geometry of the ice germ. Second, the same mechanism that leads to the decrease in the work of germ formation also decreases the mobility of water molecules near the immersed particle. These two premises allow establishing general thermodynamic constraints to the ice nucleation rate. Analysis of the new theory shows that active sites likely trigger ice nucleation, but they do not control the overall nucleation rate nor the probability of freezing. It also suggests that materials with different ice nucleation efficiency may exhibit similar freezing temperatures under similar conditions but differ in their sensitivity to particle surface area and cooling rate. Predicted nucleation rates show good agreement with observations for a diverse set of materials including dust, black carbon and bacterial ice nucleating particles. The application of the new theory within the NASA Global Earth System Model (GEOS-5) is also discussed.

A Mathematician Learns the Basics of Writing Instruction: An Immersion Experience with Long-Term Benefits

Science.gov (United States)

Doty, Lynne L.

2012-01-01

Initially designed to be an interdisciplinary experiment that would change attitudes about mathematics, the semester-long collaboration between a writing instructor and a mathematics instructor yielded unexpected long-term results. The collaboration served as an immersion in methods and techniques used by writing instructors. Description of…

Effects of whole body cryotherapy and cold water immersion on knee skin temperature

OpenAIRE

Costello, J. T.; Donnelly, A. E.; Karki, A.; Selfe, J.

2014-01-01

This study sought to a) compare and contrast the effect of 2 commonly used cryotherapy treatments, 4 min of −110°C whole body cryotherapy and 8°C cold water immersion, on knee skin temperature and b) establish whether either protocol was capable of achieving a skin temperature (

Impact of continuous positive airway pressure on the pulmonary changes promoted by immersion in water

OpenAIRE

Rizzetti, Danize Aparecida; Quadros, Janayna Rodembuch Borba; Ribeiro, Bruna Esmerio; Callegaro, Letícia; Veppo, Aline Arebalo; Wiggers, Giulia Alessandra; Peçanha, Franck Maciel

2017-01-01

ABSTRACT Objective: To determine whether different levels of CPAP improve the lung volumes and capacities of healthy subjects immersed in water. Methods: This was a randomized clinical trial, conducted between April and June of 2016, involving healthy female volunteers who were using oral contraceptives. Three 20-min immersion protocols were applied: control (no CPAP); CPAP5 (CPAP at 5 cmH2O); and CPAP10 (CPAP at 10 cmH2O). We evaluated HR, SpO2, FVC, FEV1, the FEV1/FVC ratio, peak expirato...

Effects of electron beam irradiation combined with hot water immersion treatment for shelf life extension of bananas

International Nuclear Information System (INIS)

Russly Abdul Rahman

1996-01-01

A study of the effects of minimal processing treatments, both individually or in combinations, was carried out in order to extend the shelf life and to improve the quality of bananas. Pre climacteric bananas at light full three-quarter grade, were either treated with hot water immersion for 1-30 min at 45-55 degree C, or irradiated with electron beams (2.0 MeV, Van de Graaff accelerator), to a dose of 0.1-1.5 kGy. All fruit was stored at 21 ± 1 degree C and relative humidity of 85-95 %. There was no significant delay in ripening of fruit treated with hot water immersion at the above temperatures. Some damage to fruit particularly peel scalding at ends occurred at the higher temperatures (>50 degree C). The 50 degree C, 5 minutes immersion was selected for further study. Irradiation to 0.1-0.3 kGy delayed the ripening (up to 3 days) without affecting fruit quality. Doses greater than 0.4 kGy resulted in extensive discoloration and fruit splitting. No significant differences could be detected organoleptically between bananas irradiated at 0.15 kGy and the control. Results of the physico-chemical attributes of the bananas were reported for fruits at colour stage 5 and after 10 and 15 days of storage. The combination treatment of hot water immersion and irradiation at the above settings further extended the shelf life of the banana fruits

When neuroscience gets wet and hardcore: neurocognitive markers obtained during whole body water immersion.

Science.gov (United States)

Schneider, Stefan; Cheung, Jeffrey J H; Frick, Hosea; Krehan, Sebastian; Micke, Florian; Sauer, Marc; Dalecki, Marc; Dern, Sebastian

2014-10-01

Neutral buoyancy facilities are used to prepare astronauts and cosmonauts for extra vehicular activities e.g. on-board of the International Space Station. While previous studies indicated a decrease in cognitive performance in an under water setting, they have only provided behavioural data. This study aimed to review whether recording of electro cortical activity by the use of electroencephalography (EEG) is possible in an under water setting and if so, to identify the influence of water immersion at a depth of 4 m on neurocognitive markers. Ten male subjects performed a cognitive choice-reaction times (RT) task that progressed through five levels of increasing difficulty on land and when submerged 4 m under water. N200 latency and amplitude in the occipital and frontal areas were measured, and baseline cortical activity was measured during rest in both conditions. Neither RT nor amplitude or latency of the N200 showed any significant changes between the land and the under water conditions. Also theta, alpha and beta frequencies showed no differences between the two conditions. The data provided in this study demonstrate the possibility of recording EEG even under the extreme conditions of full body water immersion. The lack of cognitive impairment in RT and N200 in the under water condition may be explained by the fact that only experienced divers participated in the study. As a proof of principle, this study generates many new experimental possibilities that will improve our understanding of cognitive processes under water.

The effect of cure conditions on the stability of cement waste forms after immersion in water

International Nuclear Information System (INIS)

Siskind, B.; Adams, J.W.; Clinton, J.H.; Piciulo, P.L.; McDaniel, K.

1988-01-01

We investigated the effects of curing conditions on the stability of cement-solidified ion-exchange resins after immersion in water. The test specimens consisted of partially depleted mixed-bed bead resins solidified in one of three vendor-supplied Portland I cement formulations, in a reference cement formulation, or in a gypsum-based binder formulation. We cured samples prepared using each formulation in sealed containers for periods of 7, 14, or 28 days as well as in air or with an accelerated heat cure prior to 90-day immersion in water. Two cement formulations exhibited apparent Portland-cement-like behavior, i.e., compressive strength increased or stabilized with increasing cure time. Two cement formulations exhibited behavior apparently unlike that of Portland cement, i.e., compressive strength decreased with increasing cure time. Such non-Portland-cement-like behavior is correlated with higher waste loadings. The gypsum-based formulation exhibited approximately constant compressive strength with cure time. Accelerated heat cures may not give compressive strengths representative of real-time cures. Some physical deterioration (cracking, spalling) of the waste form occurs during immersion

The effect of cure conditions on the stability of cement waste forms after immersion in water

International Nuclear Information System (INIS)

Siskind, B.; Adams, J.W.; Clinton, J.H.; Piciulo, P.L.

1988-01-01

The authors investigated the effects of curing conditions on the stability of cement-solidified ion-exchange resins after immersion in water. The test specimens consisted of partially depleted mixed-bed bead resins solidified in one of three vendor-supplied Portland I cement formulations, in a reference cement formulation, or in a gypsum-based binder formulation. They cured samples prepared using each formulation in sealed containers for periods of 7, 14, or 28 days as well as in air or with an accelerated heat cure prior to 90-day immersion in water. Two cement formulations exhibited apparent Portland-cement-like behavior, i.e., compressive strength increased or stabilized with increasing cure time. Two cement formulations exhibited behavior apparently unlike that of Portland cement, i.e. compressive strength decreased with increasing cure time. Such non-Portland-cement-like behavior is correlated with higher waste loadings. The gypsum-based formulation exhibited approximately constant compressive strength with cure time. Accelerated heat cures may not give compressive strengths representative of real-time cures. Some physical deterioration (cracking, spalling) of the waste form occurs during immersion

Habituation of the cold shock response is inhibited by repeated anxiety: Implications for safety behaviour on accidental cold water immersions.

Science.gov (United States)

Barwood, Martin J; Corbett, Jo; Tipton, Mike; Wagstaff, Christopher; Massey, Heather

2017-05-15

Accidental cold-water immersion (CWI) triggers the life-threatening cold shock response (CSR) which is a precursor to sudden death on immersion. One practical means of reducing the CSR is to induce an habituation by undergoing repeated short CWIs. Habituation of the CSR is known to be partially reversed by the concomitant experience of acute anxiety, raising the possibility that repeated anxiety could prevent CSR habituation; we tested this hypothesis. Sixteen participants (12 male, 4 female) completed seven, seven-minute immersions in to cold water (15°C). Immersion one acted as a control (CON1). During immersions two to five, which would ordinarily induce an habituation, anxiety levels were repeatedly increased (CWI-ANX rep ) by deception and a demanding mathematical task. Immersions six and seven were counter-balanced with another high anxiety condition (CWI-ANX rep ) or a further control (CON2). Anxiety (20cm visual analogue scale) and cardiorespiratory responses (cardiac frequency [f c ], respiratory frequency [f R ], tidal volume [V T ], minute ventilation [V̇ E ]) were measured. Comparisons were made between experimental immersions (CON1, final CWI-ANX rep , CON2), across habituation immersions and with data from a previous study. Anxiety levels were sustained at a similar level throughout the experimental and habituation immersions (mean [SD] CON1: 7.0 [4.0] cm; CON2: 5.8 [5.2] cm cf CWI-ANX rep : 7.3 [5.5] cm; p>0.05). This culminated in failure of the CSR to habituate even when anxiety levels were not manipulated (i.e. CON2). These data were different (pCSR consequently habituated. Repeated anxiety prevented CSR habituation. A protective strategy that includes inducing habituation for those at risk should include techniques to lower anxiety associated with the immersion event or habituation may not be beneficial in the emergency scenario. Copyright © 2017 Elsevier Inc. All rights reserved.

Influence of prior intense exercise and cold water immersion in recovery for performance and physiological response during subsequent exercise

DEFF Research Database (Denmark)

Christensen, Peter Møller; Bangsbo, Jens

2016-01-01

) and the influence from prior intense exercise on subsequent performance and physiological response to moderate and maximal exercise with and without the use of cold water immersion (CWI) in recovery (part B). In part A, performance times during eight World championships for male track cyclists were extracted from...... min preceded by an identical warm-up period in both a control setting (CON) and using cold water immersion in recovery (CWI; 15 min at 15°C). Performance was lowered (P

Effects of closed immersion filtered water flow velocity on the ablation threshold of bisphenol A polycarbonate during excimer laser machining

International Nuclear Information System (INIS)

Dowding, Colin; Lawrence, Jonathan

2010-01-01

A closed flowing thick film filtered water immersion technique ensures a controlled geometry for both the optical interfaces of the flowing liquid film and allows repeatable control of flow-rate during machining. This has the action of preventing splashing, ensures repeatable machining conditions and allows control of liquid flow velocity. To investigate the impact of this technique on ablation threshold, bisphenol A polycarbonate samples have been machined using KrF excimer laser radiation passing through a medium of filtered water flowing at a number of flow velocities, that are controllable by modifying the liquid flow-rates. An average decrease in ablation threshold of 7.5% when using turbulent flow velocity regime closed thick film filtered water immersed ablation, compared to ablation using a similar beam in ambient air; however, the use of laminar flow velocities resulted in negligible differences between closed flowing thick film filtered water immersion and ambient air. Plotting the recorded threshold fluence achieved with varying flow velocity showed that an optimum flow velocity of 3.00 m/s existed which yielded a minimum ablation threshold of 112 mJ/cm 2 . This is attributed to the distortion of the ablation plume effected by the flowing immersion fluid changing the ablation mechanism: at laminar flow velocities Bremsstrahlung attenuation decreases etch rate, at excessive flow velocities the plume is completely destroyed, removing the effect of plume etching. Laminar flow velocity regime ablation is limited by slow removal of debris causing a non-linear etch rate over 'n' pulses which is a result of debris produced by one pulse remaining suspended over the feature for the next pulse. The impact of closed thick film filtered water immersed ablation is dependant upon beam fluence: high fluence beams achieved greater etch efficiency at high flow velocities as the effect of Bremsstrahlung attenuation is removed by the action of the fluid on the plume; low

Immersion Pulmonary Edema in Female Triathletes

Directory of Open Access Journals (Sweden)

Eric A. Carter

2011-01-01

Full Text Available Pulmonary edema has been reported in SCUBA divers, apnea divers, and long-distance swimmers however, no instances of pulmonary edema in triathletes exist in the scientific literature. Pulmonary edema may cause seizures and loss of consciousness which in a water environment may become life threatening. This paper describes pulmonary edema in three female triathletes. Signs and symptoms including cough, fatigue, dyspnea, haemoptysis, and rales may occur within minutes of immersion. Contributing factors include hemodynamic changes due to water immersion, cold exposure, and exertion which elevate cardiac output, causing pulmonary capillary stress failure, resulting in extravasation of fluid into the airspace of the lung. Previous history is a major risk factor. Treatment involves immediate removal from immersion and in more serious cases, hospitalization, and oxygen administration. Immersion pulmonary edema is a critical environmental illness of which triathletes, race organizers, and medical staff, should be made aware.

Isometric force exaggeration in simulated weightlessness by water immersion: role of visual feedback.

Science.gov (United States)

Dalecki, Marc; Bock, Otmar

2014-06-01

Previous studies reported that humans produce exaggerated isometric forces (20-50%) in microgravity, hypergravity, and under water. Subjects were not provided with visual feedback and exaggerations were attributed to proprioceptive deficits. The few studies that provided visual feedback in micro- and hypergravity found no deficits. The present work was undertaken to find out whether visual feedback can reduce or eliminate isometric force exaggerations during shallow water immersion, a working environment for astronauts and divers. There were 48 subjects who had to produce isometric forces of 15 N with a joystick; targets were presented via screen. Procedures were similar to earlier studies, but provided visual feedback. Subjects were tested 16.4 ft (5 m) under water (WET) and on dry land (DRY). Response accuracy was calculated with landmarks such as initial and peak force magnitude, and response timing. Initial force and response timing were equal in WET compared to DRY. A small but significant force exaggeration (+5%) remained for peak force in WET that was limited to directions toward the trunk. Force exaggeration under water is largely compensated, but not completely eliminated by visual feedback. As in earlier studies without visual feedback, force exaggeration manifested during later but not early response parts, speaking for impaired proprioceptive feedback rather than for erroneous central motor planning. Since in contrast to micro/hypergravity, visual feedback did not sufficiently abolish force deficits under water, proprioceptive information seems to be weighted differently in micro/hypergravity and shallow water immersion, probably because only the latter environment produces increased ambient pressure, which is known to induce neuronal changes.

Inactivation of Salmonella in Shell Eggs by Hot Water Immersion and Its Effect on Quality.

Science.gov (United States)

Geveke, David J; Gurtler, Joshua B; Jones, Deana R; Bigley, Andrew B W

2016-03-01

Thermal inactivation kinetics of heat resistant strains of Salmonella Enteritidis in shell eggs processed by hot water immersion were determined and the effects of the processing on egg quality were evaluated. Shell eggs were inoculated with a composite of heat resistant Salmonella Enteritidis (SE) strains PT8 C405, 2 (FSIS #OB030832), and 6 (FSIS #OB040159). Eggs were immersed in a circulating hot water bath for various times and temperatures. Come-up time of the coldest location within the egg was 21 min. SE was reduced by 4.5 log at both hot water immersion treatments of 56.7 C for 60 min and 55.6 °C for 100 min. Decimal reduction times (D-values) at 54.4, 55.6, and 56.7 °C were 51.8, 14.6, and 9.33 min, respectively. The z-value was 3.07 °C. Following treatments that resulted in a 4.5 log reduction (56.7 °C/60 min and 55.6 °C/100 min), the surviving population of SE remained static during 4 wk of refrigerated storage. After processing under conditions resulting in 4.5 log reductions, the Haugh unit and albumen height significantly increased (P eggs by 4.5 log, but also significantly affected several egg quality characteristics. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Influence of a peracetic acid-based immersion on indirect composite resin.

Science.gov (United States)

Samuel, Susana Maria Werner; Fracaro, Gisele Baggio; Collares, Fabrício Mezzomo; Leitune, Vicente Castelo Branco; Campregher, Ulisses Bastos

2011-06-01

The aim of this study was to evaluate the influence of immersion in a 0.2% peracetic acid-based disinfectant on the three-point flexural strength, water sorption and water solubility of an indirect composite resin. Specimens were produced according to ISO 4049:2000 specifications and were divided in two groups: Control group, with no disinfection and Disinfected group, with three 10 min immersions in the peracetic acid intercalated with 10 min immersions in sterile distilled water. All evaluations were conducted in compliance with ISO specifications. Three-point flexural strength, water sorption and solubility of indirect composite resin before and after immersion showed no statistical significant differences (p > 0.05) and met ISO standard requirements. Immersion in peracetic acid solution showed no influence in indirect composite resin tested properties.

Comparison of acute cardiovascular responses to water immersion and head-down tilt in humans

DEFF Research Database (Denmark)

Shiraishi, Makoto; Schou, Morten; Gybel, Mikkel

2002-01-01

The hypothesis was tested that acute water immersion to the neck (WI) compared with 6 degrees head-down tilt (HDT) induces a more pronounced distension of the heart and lower plasma levels of vasoconstrictor hormones. Ten healthy males underwent 30 min of HDT, WI, and a seated control (randomized...

The Influence of Hand Immersion Duration on Manual Performance.

Science.gov (United States)

Ray, Matthew; Sanli, Elizabeth; Brown, Robert; Ennis, Kerri Ann; Carnahan, Heather

2017-08-01

To investigate the effect of hand immersion duration on manipulative ability and tactile sensitivity. Individuals in maritime settings often work with hands that have been immersed in water. Although research has shown that hand immersion duration differentially impacts skin adhesion and tactile sensitivity, the effect of hand immersion on manipulative ability has not been directly tested. Given how critical manipulative ability is for the safety and performance of those working at sea, the effect of hand immersion duration on manual performance was investigated. Tests of manipulative ability (Purdue Pegboard, Grooved Pegboard, reef knot untying) and tactile sensitivity (Touch-Test) were completed following no-exposure, short-exposure, and long-exposure hand immersions in thermoneutral water. Compared to the no immersion condition, the Purdue Pegboard performance was reduced in both immersion conditions (short exposure, -11%; long exposure, -8%). A performance decrement was only observed in the short exposure condition (+15% in time to complete task) for the reef knot untying task. There were no statistical differences in the Grooved Pegboard or Touch-Test scores between exposure conditions. Immersing the hands in water decreases manipulative ability except for when object properties reduce the slipperiness between the hand and object. Manual performance in a wet environment may be conserved by designing tools and objects with edges and textures that can offset the slipperiness of wet hands. To maintain safety, the time requirements for working with wet hands needs to be considered.

Post-exercise cold water immersion attenuates acute anabolic signalling and long-term adaptations in muscle to strength training.

Science.gov (United States)

Roberts, Llion A; Raastad, Truls; Markworth, James F; Figueiredo, Vandre C; Egner, Ingrid M; Shield, Anthony; Cameron-Smith, David; Coombes, Jeff S; Peake, Jonathan M

2015-09-15

We investigated functional, morphological and molecular adaptations to strength training exercise and cold water immersion (CWI) through two separate studies. In one study, 21 physically active men strength trained for 12 weeks (2 days per week), with either 10 min of CWI or active recovery (ACT) after each training session. Strength and muscle mass increased more in the ACT group than in the CWI group (P work (19%), type II muscle fibre cross-sectional area (17%) and the number of myonuclei per fibre (26%) increased in the ACT group (all P < 0.05), but not the CWI group. In another study, nine active men performed a bout of single-leg strength exercises on separate days, followed by CWI or ACT. Muscle biopsies were collected before and 2, 24 and 48 h after exercise. The number of satellite cells expressing neural cell adhesion molecule (NCAM) (10-30%) and paired box protein (Pax7) (20-50%) increased 24-48 h after exercise with ACT. The number of NCAM(+) satellite cells increased 48 h after exercise with CWI. NCAM(+) - and Pax7(+) -positive satellite cell numbers were greater after ACT than after CWI (P < 0.05). Phosphorylation of p70S6 kinase(Thr421/Ser424) increased after exercise in both conditions but was greater after ACT (P < 0.05). These data suggest that CWI attenuates the acute changes in satellite cell numbers and activity of kinases that regulate muscle hypertrophy, which may translate to smaller long-term training gains in muscle strength and hypertrophy. The use of CWI as a regular post-exercise recovery strategy should be reconsidered. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

Cold water immersion enhances recovery of submaximal muscle function after resistance exercise.

Science.gov (United States)

Roberts, Llion A; Nosaka, Kazunori; Coombes, Jeff S; Peake, Jonathan M

2014-10-15

We investigated the effect of cold water immersion (CWI) on the recovery of muscle function and physiological responses after high-intensity resistance exercise. Using a randomized, cross-over design, 10 physically active men performed high-intensity resistance exercise followed by one of two recovery interventions: 1) 10 min of CWI at 10°C or 2) 10 min of active recovery (low-intensity cycling). After the recovery interventions, maximal muscle function was assessed after 2 and 4 h by measuring jump height and isometric squat strength. Submaximal muscle function was assessed after 6 h by measuring the average load lifted during 6 sets of 10 squats at 80% of 1 repetition maximum. Intramuscular temperature (1 cm) was also recorded, and venous blood samples were analyzed for markers of metabolism, vasoconstriction, and muscle damage. CWI did not enhance recovery of maximal muscle function. However, during the final three sets of the submaximal muscle function test, participants lifted a greater load (P work during subsequent training sessions, which could enhance long-term training adaptations. Copyright © 2014 the American Physiological Society.

Study on Surface Permeability of Concrete under Immersion.

Science.gov (United States)

Liu, Jun; Xing, Feng; Dong, Biqin; Ma, Hongyan; Pan, Dong

2014-01-28

In this paper, concrete specimens are immersed in ultrapure water, to study the evolutions of surface permeability, pore structure and paste microstructure following the prolonging of immersion period. According to the results, after 30-day immersion, the surface permeability of concrete becomes higher as compared with the value before immersion. However, further immersion makes the surface permeability decrease, so that the value measured after 150-day immersion is only half that measured after 30-day immersion. The early increase in surface permeability should be mainly attributed to the leaching of calcium hydroxide, while the later decrease to the refinement of pore structure due to hydration. The two effects work simultaneously and compete throughout the immersion period. The proposed mechanisms get support from microscopic measurements and observations.

Partition instability in water-immersed granular systems.

Science.gov (United States)

Clement, C P; Pacheco-Martinez, H A; Swift, Michael R; King, P J

2009-07-01

It is well known that a system of grains, vibrated vertically in a cell divided into linked columns, may spontaneously move into just one of the columns due to the inelastic nature of their collisions. Here we study the behavior of a water-immersed system of spherical barium titanate particles in a rectangular cell which is divided into two columns, linked by two connecting holes, one at the top and one at the bottom of the cell. Under vibration the grains spontaneously move into just one of the columns via a gradual transfer of grains through the connecting hole at the base of the cell. We have developed numerical simulations that are able to reproduce this behavior and provide detailed information on the instability mechanism. We use this knowledge to propose a simple analytical model for this fluid-driven partition instability based on two coupled granular beds vibrated within an incompressible fluid.

Enhanced osteoblast responses to poly ether ether ketone surface modified by water plasma immersion ion implantation.

Science.gov (United States)

Wang, Heying; Lu, Tao; Meng, Fanhao; Zhu, Hongqin; Liu, Xuanyong

2014-05-01

Poly ether ether ketone (PEEK) offers a set of characteristics superior for human implants; however, its application is limited by the bio-inert surface property. In this work, PEEK surface was modified using single step plasma immersion ion implantation (PIII) treatment with a gas mixture of water vapor as a plasma resource and argon as an ionization assistant. Field emission scanning electron microscopy, atomic force microscopy and X-ray photoelectron spectroscopy were used to investigate the microstructure and composition of the modified PEEK surface. The water contact angle and zeta-potential of the surfaces were also measured. Osteoblast precursor cells MC3T3-E1 and rat bone mesenchymal stem cells were cultured on the PEEK samples to evaluate their cytocompatibility. The obtained results show that the hydroxyl groups as well as a "ravined structure" are constructed on water PIII modified PEEK. Compared with pristine PEEK, the water PIII treated PEEK is more favorable for osteoblast adhesion, spreading and proliferation, besides, early osteogenic differentiation indicated by the alkaline phosphatase activity is also up-regulated. Our study illustrates enhanced osteoblast responses to the PEEK surface modified by water PIII, which gives positive information in terms of future biomedical applications. Copyright © 2014 Elsevier B.V. All rights reserved.

Degradation of partially immersed glass: A new perspective

Science.gov (United States)

Chinnam, R. K.; Fossati, P. C. M.; Lee, W. E.

2018-05-01

The International Simple Glass (ISG) is a six-component borosilicate glass which was developed as a reference for international collaborative studies on high level nuclear waste encapsulation. Its corrosion behaviour is typically examined when it is immersed in a leaching solution, or when it is exposed to water vapour. In this study, an alternative situation is considered in which the glass is only partially immersed for 7 weeks at a temperature of 90 °C. In this case, half of the glass sample is directly in the solution itself, and the other half is in contact with a water film formed by condensation of water vapour that evaporated from the solution. This results in a different degradation behaviour compared to standard tests in which the material is fully immersed. In particular, whilst in standard tests the system reaches a steady state with a very low alteration rate thanks to the formation of a protective gel layer, in partially-immersed tests this steady state could not be reached because of the continuous alteration from the condensate water film. The constant input of ions from the emerged part of the sample caused a supersaturation of the solution, which resulted in early precipitation of secondary crystalline phases. This setup mimics storage conditions once small amounts of water have entered a glass waste form containing canister. It offers a more realistic outlook of corrosion mechanisms happening in such situations than standard fully-immersed corrosion tests.

The use of continuous vs. intermittent cold water immersion as a recovery method in basketball players after training: a randomized controlled trial.

Science.gov (United States)

Sánchez-Ureña, Braulio; Martínez-Guardado, Ismael; Crespo, Carmen; Timón, Rafael; Calleja-González, Julio; Ibañez, Sergio J; Olcina, Guillermo

2017-05-01

The main objective of this study was to compare two cold water immersion protocols, continuous or intermittent, on recovery in basketball players. Ten male basketball players (age: 14 ± 0.4 years, body mass: 65.4 ± 9.1 kg, height: 175 ± 7.3 cm, body fat %: 10.3 ± 4) were included in the study. After three 90-minute training sessions (avg. heart rate 158 ± 11.92, 156 ± 7.06 and 151 ± 10.44 bpm), participants were grouped into a continuous immersion (12 min at 12 ± 0.4°C) group, intermittent immersion (4 x 2 min immersion at 12 ± 0.4 °C + 1 min out of water) group and a control group (CG). Countermovement jump (CMJ), muscle pain and thigh volume were measured. Both cold water immersion protocols were effective in reducing the pain 24 and 48 hours after training compared with the CG (F (3.54) = 2.91, p = 0.016, η p 2  = .24). Concerning CMJ change, % differences occurred at 24 (Z = 11.04, p = 0.004) and 48 hours (Z = 14.01, p basketball players.

Effects of postexercise ice-water and room-temperature water immersion on the sensory organization of balance control and lower limb proprioception in amateur rugby players: A randomized controlled trial.

Science.gov (United States)

Chow, Gary C C; Yam, Timothy T T; Chung, Joanne W Y; Fong, Shirley S M

2017-02-01

This single-blinded, three-armed randomized controlled trial aimed to compare the effects of postexercise ice-water immersion (IWI), room-temperature water immersion (RWI), and no water immersion on the balance performance and knee joint proprioception of amateur rugby players. Fifty-three eligible amateur rugby players (mean age ± standard deviation: 21.6 ± 2.9 years) were randomly assigned to the IWI group (5.3 °C), RWI group (25.0 °C), or the no immersion control group. The participants in each group underwent the same fatigue protocol followed by their allocated recovery intervention, which lasted for 1 minute. Measurements were taken before and after the fatigue-recovery intervention. The primary outcomes were the sensory organization test (SOT) composite equilibrium score (ES) and the condition-specific ES, which were measured using a computerized dynamic posturography machine. The secondary outcome was the knee joint repositioning error. Two-way repeated measures analysis of variance was used to test the effect of water immersion on each outcome variable. There were no significant within- and between-group differences in the SOT composite ESs or the condition-specific ESs. However, there was a group-by-time interaction effect on the knee joint repositioning error. It seems that participants in the RWI group had lower errors over time, but those in the IWI and control groups had increased errors over time. The RWI group had significantly lower error score than the IWI group at postintervention. One minute of postexercise IWI or RWI did not impair rugby players' sensory organization of balance control. RWI had a less detrimental effect on knee joint proprioception to IWI at postintervention.

Impairment of exercise performance following cold water immersion is not attenuated after 7 days of cold acclimation.

Science.gov (United States)

Jones, Douglas M; Roelands, Bart; Bailey, Stephen P; Buono, Michael J; Meeusen, Romain

2018-03-19

It is well-documented that severe cold stress impairs exercise performance. Repeated immersion in cold water induces an insulative type of cold acclimation, wherein enhanced vasoconstriction leads to greater body heat retention, which may attenuate cold-induced exercise impairments. The purpose of this study, therefore, was to investigate changes in exercise performance during a 7-day insulative type of cold acclimation. Twelve healthy participants consisting of eight males and four females (mean ± SD age: 25.6 ± 5.2 years, height: 174.0 ± 8.9 cm, weight: 75.6 ± 13.1 kg) performed a 20 min self-paced cycling test in 23 °C, 40% humidity without prior cold exposure. Twenty-four hours later they began a 7-day cold acclimation protocol (daily 90 min immersion in 10 °C water). On days one, four, and seven of cold acclimation, participants completed the same cycling test. Measurements of work completed, core and skin temperatures, heart rate, skin blood flow, perceived exertion, and thermal sensation were measured during each cycling test. Successful insulative cold acclimation was observed. Work produced during the baseline cycling test (220 ± 70 kJ) was greater (p immersions (195 ± 58, 197 ± 60, and 194 ± 62 kJ) despite similar ratings of perceived exertion during each test, suggesting that cold exposure impaired cycling performance. This impairment, however, was not attenuated over the cold acclimation period. Results suggest that insulative cold acclimation does not attenuate impairments in exercise performance that were observed following acute cold water immersion.

Correction factors for assessing immersion suits under harsh conditions.

Science.gov (United States)

Power, Jonathan; Tikuisis, Peter; Ré, António Simões; Barwood, Martin; Tipton, Michael

2016-03-01

Many immersion suit standards require testing of thermal protective properties in calm, circulating water while these suits are typically used in harsher environments where they often underperform. Yet it can be expensive and logistically challenging to test immersion suits in realistic conditions. The goal of this work was to develop a set of correction factors that would allow suits to be tested in calm water yet ensure they will offer sufficient protection in harsher conditions. Two immersion studies, one dry and the other with 500 mL of water within the suit, were conducted in wind and waves to measure the change in suit insulation. In both studies, wind and waves resulted in a significantly lower immersed insulation value compared to calm water. The minimum required thermal insulation for maintaining heat balance can be calculated for a given mean skin temperature, metabolic heat production, and water temperature. Combining the physiological limits of sustainable cold water immersion and actual suit insulation, correction factors can be deduced for harsh conditions compared to calm. The minimum in-situ suit insulation to maintain thermal balance is 1.553-0.0624·TW + 0.00018·TW(2) for a dry calm condition. Multiplicative correction factors to the above equation are 1.37, 1.25, and 1.72 for wind + waves, 500 mL suit wetness, and both combined, respectively. Calm water certification tests of suit insulation should meet or exceed the minimum in-situ requirements to maintain thermal balance, and correction factors should be applied for a more realistic determination of minimum insulation for harsh conditions. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Altered Gravity Simulated by Parabolic Flight and Water Immersion Leads to Decreased Trunk Motion.

Directory of Open Access Journals (Sweden)

Peiliang Wang

Full Text Available Gravity is one of the important environmental factors that influence the physiologies and behaviors of animals and humans, and changes in gravity elicit a variety of physiological and behavioral alterations that include impaired movement coordination, vertigo, spatial disorientation, and perceptual illusions. To elucidate the effects of gravity on human physiology and behavior, we examined changes in wrist and trunk activities and heart rate during parabolic flight and the activity of wrist and trunk in water immersion experiments. Data from 195 person-time parabolas performed by eight subjects revealed that the trunk motion counts decreased by approximately half during ascending legs (hypergravity, relative to the data acquired before the parabolic flights. In contrast, the wrist activity remained unchanged. The results from the water immersion experiments demonstrated that in the underwater condition, both the wrist and trunk activities were significantly decreased but the latter decreased to a much lower level. Together, these data suggest that gravitational alterations can result in differential influences on the motions of the wrist and the trunk. These findings might be important for understanding the degeneration of skeleton and muscular system and performance of astronauts in microgravity.

Altered Gravity Simulated by Parabolic Flight and Water Immersion Leads to Decreased Trunk Motion

Science.gov (United States)

Tian, Yu; Li, Fan; Zhang, Shaoyao; Zhang, Lin; Guo, Yaoyu; Liu, Weibo; Wang, Chunhui; Chen, Shanguang; Guo, Jinhu

2015-01-01

Gravity is one of the important environmental factors that influence the physiologies and behaviors of animals and humans, and changes in gravity elicit a variety of physiological and behavioral alterations that include impaired movement coordination, vertigo, spatial disorientation, and perceptual illusions. To elucidate the effects of gravity on human physiology and behavior, we examined changes in wrist and trunk activities and heart rate during parabolic flight and the activity of wrist and trunk in water immersion experiments. Data from 195 person-time parabolas performed by eight subjects revealed that the trunk motion counts decreased by approximately half during ascending legs (hypergravity), relative to the data acquired before the parabolic flights. In contrast, the wrist activity remained unchanged. The results from the water immersion experiments demonstrated that in the underwater condition, both the wrist and trunk activities were significantly decreased but the latter decreased to a much lower level. Together, these data suggest that gravitational alterations can result in differential influences on the motions of the wrist and the trunk. These findings might be important for understanding the degeneration of skeleton and muscular system and performance of astronauts in microgravity. PMID:26208253

Microbiological evaluation of chicken carcasses in an immersion chilling system with water renewal at 8 and 16 hours.

Science.gov (United States)

Souza, L C T; Pereira, J G; Spina, T L B; Izidoro, T B; Oliveira, A C; Pinto, J P A N

2012-05-01

Since 2004, Brazil has been the leading exporter of chicken. Because of the importance of this sector in the Brazilian economy, food safety must be ensured by control and monitoring of the production stages susceptible to contamination, such as the chilling process. The goal of this study was to evaluate changes in microbial levels on chicken carcasses and in chilling water after immersion in a chilling system for 8 and 16 h during commercial processing. An objective of the study was to encourage discussion regarding the Brazilian Ministry of Agriculture Livestock and Food Supply regulation that requires chicken processors to completely empty, clean, and disinfect each tank of the chilling system after every 8-h shift. Before and after immersion chilling, carcasses were collected and analyzed for mesophilic bacteria, Enterobacteriaceae, coliforms, and Escherichia coli. Samples of water from the chilling system were also analyzed for residual free chlorine. The results do not support required emptying of the chiller tank after 8 h; these tanks could be emptied after 16 h. The results for all carcasses tested at the 8- and 16-h time points indicated no significant differences in the microbiological indicators evaluated. These data provide both technical and scientific support for discussing changes in federal law regarding the management of immersion chilling water systems used as part of the poultry processing line.

Experimental effects of immersion time and water temperature on body condition, burying depth and timing of spawning of the tellinid bivalve Macoma balthica

Science.gov (United States)

de Goeij, Petra; Honkoop, Pieter J.

2003-03-01

The burying depth of many bivalve molluscs on intertidal mudflats varies throughout the year and differs between places. Many factors are known to influence burying depth on a seasonal or spatial scale, with temperature and tidal regime probably being very important. Burying depth, body condition and gonadal development of Macoma balthica were followed throughout winter and spring in an experiment in which water temperature and immersion time were manipulated. Unexpectedly, relative water temperature, in contrast to the prediction, did not generally affect body condition or burying depth. This was probably a consequence of the exceptionally overall low water temperatures during the experimental winter. Differences in temperature did, however, result in different timing of spawning: M. balthica spawned earlier at higher spring temperatures. Longer immersion times led to higher body condition only late in spring, but led to deeper burying throughout almost the whole period. There was no effect of immersion time on the timing of spawning. We conclude that a longer immersion time leads to deeper burying, independent of body condition. We also conclude that burying behaviour of M. balthica is not determined by the moment of spawning.

Hot water immersion as a treatment for stonefish sting: A case report

Directory of Open Access Journals (Sweden)

Darlene F. Ongkili

2013-05-01

Full Text Available The North Borneo state of Sabah is known worldwide for its beautiful islands and dive sites. Local hospitals deal with a number of marine-related injuries, including marine fauna envenomation by Scorpaenidae and Synanceiidae families of fish. We report a case of a tourist who presented with excruciating pain on her right foot after stepping on a stonefish. Despite being given parenteral analgesia and regional anaesthesia, the pain persisted. Her pain improved after she soaked her foot in hot water for about 30 minutes. No further treatment was required. We reviewed the literature comparing this inexpensive mode of treatment with other conventional treatments. We also explored the possibility of using hot water immersion for treatment of envenomation by other types of marine animals.

Study of corrosion processes on Al-AA 6061 crevices immersed in high purity water and sodium citrate solution

International Nuclear Information System (INIS)

Rodriguez, Sebastian A.; Haddad, Roberto; Lanzani, Liliana A.

2004-01-01

An experimental approach has been developed to study the corrosion behavior of artificial crevices manufactured with high purity aluminum and AA 6061 alloy, immersed in dematerialised water and sodium citrate solution (96,5 μS/cm). Alkaline attack was found on the surrounding of iron rich particles in the external zone of the crevice, as a result of localized oxygen reduction reaction on these sites. This attack was not observed in the zone inside the crevice. Study of the phase Mg 2 Si by EDS allowed establishing that there is not preferential dissolution inside the crevice. The formation of a stable and non-soluble complex between Al and citrate anion inhibited the production of Al(OH) 3 precipitate, which was observed on the surface of specimens immersed in pure water. Investigations of the aluminum oxide evolution on AA 6061 surfaces in water showed that it was composed by two layers: an internal one made of Bohemite and an external one in direct contact with the water, with a Bayerite structure. The surface analysis was accomplished using XR, OM and SEM techniques. (author) [es

Dynamic lifetimes of cagelike water clusters immersed in liquid water and their implications for hydrate nucleation studies

Energy Technology Data Exchange (ETDEWEB)

Guo, G.J.; Zhang, Y.G.; Li, M.; Wu, C.H. [Chinese Academy of Sciences, Inst. of Geology and Geophysics, Beijing (China). Key Laboratory of the Study of Earth' s Deep Interior

2008-07-01

In hydrate research fields, the hydrate nucleation mechanism still remains as an unsolved question. The static lifetimes of cagelike water clusters (CLWC) immersed in bulk liquid water have recently been measured by performing molecular dynamics simulations in the methane-water system, during which the member-water molecules of CLWCs are not allowed to exchange with their surrounding water molecules. This paper presented a study that measured the dynamic lifetimes of CLWCs permitting such water exchanges. The study involved re-analysis of previous simulation data that were used to study the effect of methane adsorption on the static lifetimes of a dodecahedral water cluster (DWC). The dynamic lifetimes of the DWC were calculated. The results of lifetime measurements of DWC in different systems were provided. The implications of this study for hydrate nucleation were also discussed. It was found that the dynamic lifetimes of CLWCs were not less than the static lifetimes previously obtained, and their ratio increased with the lifetime values. The results strengthened that CLWCs are metastable structures in liquid water and the occurrence probability of long-lived CLWCs will increase if one uses the dynamic lifetimes instead of the static lifetimes. 13 refs., 1 tab., 3 figs.

Immersion technique in soft tissue radiography of the hands

International Nuclear Information System (INIS)

Maekelae, P.; Haaslahti, J.O.

1978-01-01

Soft tissue radiography of hands using the technique of mammary radiography and immersion in a 2.5 cm layer of 1 : 1 water-ethanol solution is evaluated. Using immersion the average background density decreases with a factor of about 2.5 : 1, with little deterioration in resolution (MTF). The immersion procedure makes the demonstration and evaluation of soft tisse swelling and periarticular oedema easier. (Auth.)

Immersion microcalorimetry of a carbon black

International Nuclear Information System (INIS)

Mendelbaum, Georges

1966-01-01

This research thesis first reports a detailed bibliographical study on various topics (fabrication of carbon black, oxidation, immersion heat, adsorptions, main existing theories, and thermodynamics) and then the development of immersion and adsorption microcalorimetry apparatuses aimed at studying the surface of a carbon black and the influence of the oxidation of this carbon black on the adsorption of polar and non-polar solvents. Immersion heats of a raw or oxidised carbon black have been measured in water, in cyclohexane and in methanol. The adsorption of methanol at 20 C and that of nitrogen at -196 C have also been measured. The author outlines that degassing conditions had to be taken into account before performing measurements [fr

A customised cold-water immersion protocol favours one-size-fits-all protocols in improving acute performance recovery

NARCIS (Netherlands)

Zandvoort, Coen S.; de Zwart, Jelmer R.; van Keeken, Brenda L.; Viroux, Patrick J.F.; Tiemessen, Ivo J.H.

The purpose of the present study was to investigate whether a customised cold-water immersion (CWIc) protocol was more effective in enhancing acute performance recovery than a one-size-fits-all CWI (CWIs) or active recovery (AR) protocol. On three separate testing days, 10 healthy, physically

Clinical and histopathologic features of dorsally located furunculosis in dogs following water immersion or exposure to grooming products: 22 cases (2005-2013).

Science.gov (United States)

Cain, Christine L; Mauldin, Elizabeth A

2015-03-01

To describe clinical and histopathologic features of furunculosis in dogs following water immersion or exposure to grooming products. Retrospective case series. 22 dogs with skin lesions consistent with furunculosis and a history of water immersion or grooming prior to onset. Procedures-Information collected from the medical records of affected dogs included signalment, clinical signs, bathing or grooming procedure, diagnostic tests, treatment, and outcome. German Shepherd Dogs (4/22 [18%]) and Labrador Retrievers (4/22 [18%]) were most commonly affected. Skin lesions, particularly hemorrhagic pustules and crusts, were dorsally located in all dogs and occurred a median of 2 days (range, 1 to 7 days) following water immersion or exposure to grooming products. Twenty (91%) dogs were bathed at home or at a commercial grooming facility prior to lesion onset; 1 dog developed skin lesions following hydrotherapy on an underwater treadmill, and 1 dog developed peri-incisional skin lesions after surgery. Lethargy, signs of neck or back pain, and fever were common clinical signs. Pseudomonas aeruginosa was the most common bacterial isolate from dogs with bacteriologic culture performed on skin samples (10/14). The main histologic feature was acute follicular rupture in the superficial dermis with suppurative inflammation and dermal hemorrhage. Systemic antimicrobial treatment, particularly oral administration of fluoroquinolones, resulted in excellent clinical response in 16 of 22 (73%) dogs. Acute-onset furunculosis with characteristic clinical and histopathologic features in dogs following water immersion or exposure to grooming products was described. Knowledge of the historical and clinical features of this syndrome is essential for accurate diagnosis and appropriate treatment of affected dogs.

Kenaf Fibre Reinforced Polypropylene Composites: Effect of Cyclic Immersion on Tensile Properties

Directory of Open Access Journals (Sweden)

W. H. Haniffah

2015-01-01

Full Text Available This research studied the degradation of tensile properties of kenaf fibre reinforced polypropylene composites due to cyclic immersion into two different solutions, as well as comparison of the developed composites’ tensile properties under continuous and cyclic immersion. Composites with 40% and 60% fibre loadings were immersed in tap water and bleach for 4 cycles. Each cycle consisted of 3 days of immersion and 4 days of conditioning in room temperature (28°C and 55% humidity. The tensile strength and modulus of composites were affected by fibre composition, type of liquid of immersion, and number of cycles. The number of immersion cycles and conditioning caused degradation to tensile strength and modulus of kenaf fibre reinforced polypropylene composites. Continuous and cyclic immersion in bleach caused tensile strength of the composites to differ significantly whereas, for tensile modulus, the difference was insignificant in any immersion and fibre loadings. However, continuous immersion in the bleach reduced the tensile strength of composites more compared to cyclic immersion. These preliminary results suggest further evaluation of the suitability of kenaf fibre reinforced polypropylene composites for potential bathroom application where the composites will be exposed to water/liquid in cyclic manner due to discontinuous usage of bathroom.

The effects of cold immersion and hand protection on grip strength.

Science.gov (United States)

Vincent, M J; Tipton, M J

1988-08-01

The maximal voluntary grip strength (MVGS) of male volunteers was examined following a series of five intermittent 2 min cold water (5 degrees C) immersions of the unprotected hand or forearm. MVGS changes due to wearing a protective glove were also investigated. The surface electrical activity over the hand flexor muscles was recorded, as was the skin temperature of the hand and forearm. MVGS decreased significantly (p less than 0.01) following hand immersions (16%) and forearm immersion (13%). The majority of these reductions occurred during the first 2-min period of immersion. The effect of wearing a glove after unprotected hand cooling also produced significant (p less than 0.01) MVGS reductions which averaged 14%. These reductions were in addition to those caused by hand cooling. We conclude that both hand and forearm protection are important for the maintenance of hand-grip strength following cold water immersion.

Cold water immersion of the ankle decreases neuromuscular response of lower limb after inversion movement

OpenAIRE

Macedo, Christiane S. G.; Alonso, Carolina S.; Liporaci, Rogério F.; Vieira, Fernando; Guirro, Rinaldo R. J.

2014-01-01

BACKGROUND: Cryotherapy has been associated with a significant decrease in nerve conduction velocity and muscle contraction with possible effects on exercise and physical training. OBJECTIVES: To quantify the electromyographic response of the lateral gastrocnemius, tibialis anterior, fibularis longus, rectus femoris and gluteus medius to ankle inversion following cold water immersion. METHOD: The peak values of the root mean square (RMS) were obtained from 35 healthy and active univ...

Head-out immersion in hot water increases serum BDNF in healthy males.

Science.gov (United States)

Kojima, Daisuke; Nakamura, Takeshi; Banno, Motohiko; Umemoto, Yasunori; Kinoshita, Tokio; Ishida, Yuko; Tajima, Fumihiro

2017-11-20

Brain-derived neurotrophic factor (BDNF) is an important neurotrophin. The present study investigated the effects of head-out water immersion (HOI) on serum BDNF concentrations. Eight healthy men performed 20 min head-out water immersion at 42 °C (hot-HOI) and 35 °C (neutral-HOI). These experimental trials were administered in a randomised order separated by at least 7 days. Venous blood samples were withdrawn at rest, immediately after the 20-min HOI, as well as at 15 and 30 min after the end of the HOI. Serum BDNF and S100β, plasma cortisol, platelet and monocyte counts, and core body temperature (T cb ) were measured. T cb was higher at the end of the hot-HOI and 15 min after hot-HOI (p hot-HOI. No change in T cb was recorded during neutral-HOI. BDNF level was higher (p hot-HOI and at 15 min after the end of hot-HOI, and returned to the baseline at 30 min after hot-HOI. S100β, platelet count and monocyte count remained stable throughout the study. Cortisol level was lower at the end of the hot-HOI and returned to pre-HOI level during the recovery period. BDNF and S100β, cortisol, and platelet and monocyte counts did not change throughout the neutral-HOI study. The present findings suggested that the increase in BDNF during 20-min hot-HOI was induced by hyperthermia through enhanced production, rather than by changes in permeability of the blood-brain barrier (BBB), platelet clotting mechanisms or secretion from monocytes.

Breath-hold time during cold water immersion: effects of habituation with psychological training.

Science.gov (United States)

Barwood, Martin J; Datta, Avijit K; Thelwell, Richard C; Tipton, Michael J

2007-11-01

The loss of the conscious control of respiration on whole body cold water immersion (CWI) can result in the aspiration of water and drowning. Repeated CWI reduces the respiratory drive evoked by CWI and should prolong breath-hold time on CWI (BHmax(CWI)). Psychological skills training (PST) can also increase BHmax(CWI) by improving the ability of individuals to consciously suppress the drive to breathe. This study tested the hypothesis that combining PST and repeated CWI would extend BHmax(CWI) beyond that seen following only repeated CWI. There were 20 male subjects who completed two 2.5-min, head-out breath-hold CWI (BH1 and BH2) in water at 12 degrees C. Following BH1, subjects were matched on BHmax(CWI) and allocated to a habituation (HAB) group or a habituation plus PST group (H+PST). Between BH1 and BH2 both experimental groups undertook five 2.5-min CWI on separate days, during which they breathed freely. The H+PST also received psychological training to help tolerate cold and suppress the drive to breathe on immersion to extend BHmax(CWI). During BH1, mean BHmax(CWI) (+/- SD) in the HAB group was 22.00 (10.33) s and 22.38 (10.65) s in the H+PST. After the five free-breathing CWI, both groups had a longer BHmax(CWI) in BH2. The HAB group improved by 14.13 (20.21) s, an increase of 73%. H+PST improved by 26.86 (24.70) s, a 120% increase. No significant differences were identified between the groups. Habituation significantly increases BHmax on CWI, the addition of PST did not result in statistically significant improvements in BHmax(CWI), but may have practical significance.

Cold-induced vasodilation during single digit immersion in 0°C and 8°C water in men and women.

Directory of Open Access Journals (Sweden)

Christopher James Tyler

Full Text Available The present study compared the thermal responses of the finger to 0 and 8°C water immersion, two commonly used temperatures for cold-induced vasodilation (CIVD research. On two separate and counterbalanced occasions 15 male and 15 female participants immersed their index finger in 20°C water for 5 min followed by either 0 or 8°C water for 30 min. Skin temperature, cardiovascular and perceptual data were recorded. Secondary analyses were performed between sexes and comparing 0.5, 1 and 4°C CIVD amplitude thresholds. With a 0.5°C threshold, CIVD waves were more prevalent in 8°C (2 (1-3 than in 0°C (1.5 (0-3, but the amplitude was lower (4.0 ± 2.3 v 9.2 ± 4.0°C. Mean, minimum and maximum finger temperatures were lower in 0°C during the 30 min immersion, and CIVD onset and peak time occurred later in 0°C. Thermal sensation was lower and pain sensation was higher in 0°C. There were no differences between males and females in any of the physiological or CIVD data with the exception of SBP, which was higher in males. Females reported feeling higher thermal sensations in 8°C and lower pain sensations in 0°C and 8°C compared to males. Fewer CIVD responses were observed when using a 4°C (1 (0-3 threshold to quantify a CIVD wave compared to using a 1°C (2 (0-3 or 0.5°C (2 (0-3 amplitude. In conclusion, both 0 and 8 °C can elicit CIVD but 8°C may be more suitable when looking to optimise the number of CIVD waves while minimising participant discomfort. The CIVD response to water immersion does not appear to be influenced by sex. Researchers should consider the amplitude threshold that was used to determine a CIVD wave when interpreting previous data.

Immersion revisited

DEFF Research Database (Denmark)

Nilsson, Niels Chr.; Nordahl, Rolf; Serafin, Stefania

2016-01-01

of existing definitions of immersion originating within the study of video games, virtual environments, and literary works of fiction. Based on this review, a three-dimensional taxonomy of the various conceptualizations of immersion is proposed. That is, the existing definitions of immersion may be broadly...... divided into three categories, each representing a dimension of the taxonomy: immersion as a property of a system, a subjective response to narrative contents, or a subjective response to challenges within the virtual environment. Finally, four distinct theories of presence are introduced and, based...... on the established taxonomy, we discuss how the individual theories relate to existing definitions of immersion....

Metabolic and cardiorespiratory response in swimmers during head-out immersion: a prospective study.

Science.gov (United States)

Mesfar, Mohamed A; Zendah, Ines; Gharsalli, Houda; Ben Hassen, Chokri; Ghedira, Habib

2012-11-01

Sport represents a stress for the body. Many metabolic and cardiorespiratory changes are known during physical activity.However, litte is known in swimmers particularly during head-out immersion. To determine the metabolic and cardiorespiratory response in swimmers during head-out immersion. The energetic, cardiovascular function and ventilatory requirements of a 10 min steady state arm exercise performed by 13 healthy subjects in air and during immersion up to the hip in 26°C water were compared. The same ergometric work load was achieved with an average maximum oxygen uptake of 3.9 ± 2.63 l/min in air versus 3.55 ± 2.48 l/min in water (p=0.953). During exercise, the average values of minute ventilation, ventilation equivalent for oxygen, ventilation equivalent for CO2, peak expiratory flow, respiratory exchange ratio and heart rate were not different in water and in air. However, first ventilatory threshold was significantly higher in water than in air. The mean value of the first ventilatory threshold was 0.89 ± 0.23 l/min in air, and 1.08 ± 0.23 l/min in water immersion; (p=0.016). These results suggest that training swimmers favoring immersion (weight belts) may improve their aerobic capacity.

Effect of Cold (14° C) vs. Ice (5° C) Water Immersion on Recovery From Intermittent Running Exercise.

Science.gov (United States)

Anderson, Daniel; Nunn, James; Tyler, Christopher J

2018-03-01

Anderson, D, Nunn, J, and Tyler, CJ. Effect of cold (14° C) vs. ice (5° C) water immersion on recovery from intermittent running exercise. J Strength Cond Res 32(3): 764-771, 2018-The purpose was to compare 14° C (CWI14° C) and 5° C (CWI5° C) cold water immersion after intermittent running. On 3 occasions, 9 male team-sport players undertook 12 minutes of CWI14° C, CWI5° C, or nonimmersed seated recovery (CON) after 45 minutes of intermittent running exercise. Maximal cycling performance and markers of recovery were measured before and in the 0-72 hours after exercise. Peak power output (PPO) was immediately reduced after all interventions (d = 1.8). CWI5° C was more effective at restoring PPO than CWI14° C (d = 0.38) and CON (d = 0.28) 24 hours after exercise, whereas both CON (d = 0.20) and CWI5 (d = 0.37) were more effective than CWI14° C after 48 hours. Cold water immersion (CWI) was more effective than CON at restoring PPO 72 hours after exercise (d = 0.28-0.30). Mean power output (MPO) was higher in CON compared with CWI5° C (d = 0.30) and CWI14° C (d = 0.21), but there was no difference between CWI5° C and CWI14° C (d = 0.08). CWI5° C was more effective than CWI14° C for restoring MPO to baseline levels 24 hours (d = 0.28) and 72 hours (d = 0.28) after exercise; however, CON was more, or equally, effective as CWI5° C and CWI14° C throughout. Lactate and creatine kinase concentrations were unaffected. Perceived muscle soreness remained elevated in CWI5 and CON throughout but was similar to baseline in CWI14° C after 72 hours. In conclusion, repeated bouts of exercise are initially impaired after 5 and 14° C CWI, but PPO may be improved 72 hours after exercise. Cold water immersion is not recommended for acute recovery based on these data. Athletes and coaches should use the time currently allocated to CWI for more effective and alternative recovery modalities.

Immersion freezing of water and aqueous ammonium sulfate droplets initiated by humic-like substances as a function of water activity

Directory of Open Access Journals (Sweden)

Y. J. Rigg

2013-07-01

Full Text Available Immersion freezing of water and aqueous (NH42SO4 droplets containing leonardite (LEO and Pahokee peat (PP serving as surrogates for humic-like substances (HULIS has been investigated. Organic aerosol containing HULIS are ubiquitous in the atmosphere; however, their potential for ice cloud formation is uncertain. Immersion freezing has been studied for temperatures as low as 215 K and solution water activity, aw, from 0.85 to 1.0. The freezing temperatures of water and aqueous solution droplets containing LEO and PP are 5–15 K warmer than homogeneous ice nucleation temperatures. Heterogeneous freezing temperatures can be represented by a horizontal shift of the ice melting curve as a function of solution aw by Δaw = 0.2703 and 0.2466, respectively. Corresponding hetrogeneous ice nucleation rate coefficients, Jhet, are (9.6 ± 2.5×104 and (5.4 ± 1.4×104 cm−2 s−1 for LEO and PP containing droplets, respectively, and remain constant along freezing curves characterized by Δaw. Consequently predictions of freezing temperatures and kinetics can be made without knowledge of the solute type when relative humidity and ice nuclei (IN surface areas are known. The acquired ice nucleation data are applied to evaluate different approaches to fit and reproduce experimentally derived frozen fractions. In addition, we apply a basic formulation of classical nucleation theory (α(T-model to calculate contact angles and frozen fractions. Contact angles calculated for each ice nucleus as a function of temperature, α(T-model, reproduce exactly experimentally derived frozen fractions without involving free-fit parameters. However, assigning the IN a single contact angle for the entire population (single-α model is not suited to represent the frozen fractions. Application of α-PDF, active sites, and deterministic model approaches to measured frozen fractions yield similar good representations. Furthermore, when using a single parameterization of α-PDF or

IQ-Station: A Low Cost Portable Immersive Environment

Energy Technology Data Exchange (ETDEWEB)

Eric Whiting; Patrick O' Leary; William Sherman; Eric Wernert

2010-11-01

The emergence of inexpensive 3D TV’s, affordable input and rendering hardware and open-source software has created a yeasty atmosphere for the development of low-cost immersive environments (IE). A low cost IE system, or IQ-station, fashioned from commercial off the shelf technology (COTS), coupled with a targeted immersive application can be a viable laboratory instrument for enhancing scientific workflow for exploration and analysis. The use of an IQ-station in a laboratory setting also has the potential of quickening the adoption of a more sophisticated immersive environment as a critical enabler in modern scientific and engineering workflows. Prior work in immersive environments generally required either a head mounted display (HMD) system or a large projector-based implementation both of which have limitations in terms of cost, usability, or space requirements. The solution presented here provides an alternative platform providing a reasonable immersive experience that addresses those limitations. Our work brings together the needed hardware and software to create a fully integrated immersive display and interface system that can be readily deployed in laboratories and common workspaces. By doing so, it is now feasible for immersive technologies to be included in researchers’ day-to-day workflows. The IQ-Station sets the stage for much wider adoption of immersive environments outside the small communities of virtual reality centers.

Discoloration of various CAD/CAM blocks after immersion in coffee

Directory of Open Access Journals (Sweden)

Sasipin Lauvahutanon

2017-02-01

Full Text Available Objectives This study evaluated color differences (ΔEs and translucency parameter changes (ΔTPs of various computer-aided design/computer-aided manufacturing (CAD/CAM blocks after immersion in coffee. Materials and Methods Eight CAD/CAM blocks and four restorative composite resins were evaluated. The CIE L*a*b* values of 2.0 mm thick disk-shaped specimens were measured using the spectrophotometer on white and black backgrounds (n = 6. The ΔEs and ΔTPs of one day, one week, and one month immersion in coffee or water were calculated. The values of each material were analyzed by two-way ANOVA and Tukey's multiple comparisons (α = 0.05. The ΔEs after prophylaxis paste polishing of 1 month coffee immersion specimens, water sorption and solubility were also evaluated. Results After one month in coffee, ΔEs of CAD/CAM composite resin blocks and restorative composites ranged from 1.6 to 3.7 and from 2.1 to 7.9, respectively, and ΔTPs decreased. The ANOVA of ΔEs and ΔTPs revealed significant differences in two main factors, immersion periods and media, and their interaction except for ΔEs of TEL (Telio CAD, Ivoclar Vivadent. The ΔEs significantly decreased after prophylaxis polishing except GRA (Gradia Block, GC. There was no significant correlation between ΔEs and water sorption or solubility in water. Conclusions The ΔEs of CAD/CAM blocks after immersion in coffee varied among products and were comparable to those of restorative composite resins. The discoloration of CAD/CAM composite resin blocks could be effectively removed with prophylaxis paste polishing, while that of some restorative composites could not be removed.

Long-term water absorption tests for frost insulation materials taking into account frost attack

Directory of Open Access Journals (Sweden)

Toni A. Pakkala

2014-01-01

Full Text Available Water absorption of several different frost insulation materials was tested for four years. The test took into account both immersion and frost attack to materials. On the basis of the research the water absorption on XPS specimens is significantly minor compared to EPS specimens that were studied. The most significant result was that freezing of test specimens did not affect on water absorption of XPS specimens but had a major effect on water absorption of EPS specimens. With frozen EPS specimen the absorption continued increasing even after 48 months of immersion. Presumably the reason for such a behaviour is that the pore structure of EPS is not able to resist the tension caused by freezing water and therefore cracks are formed. Thus, more water absorbs inside the EPS through the cracks and it causes cracking deeper in the specimen which is why absorption increases after every freezing period.

33 CFR 150.518 - What are the inspection requirements for work vests and immersion suits?

Science.gov (United States)

2010-07-01

... requirements for work vests and immersion suits? 150.518 Section 150.518 Navigation and Navigable Waters COAST... vests and immersion suits? (a) All work vests and immersion suits must be inspected by the owner or... a work vest or immersion suit is inspected and is in serviceable condition, then it may remain in...

Cardiorespiratory responses and reduced apneic time to cold-water face immersion after high intensity exercise.

Science.gov (United States)

Konstantinidou, Sylvia; Soultanakis, Helen

2016-01-01

Apnea after exercise may evoke a neurally mediated conflict that may affect apneic time and create a cardiovascular strain. The physiological responses, induced by apnea with face immersion in cold water (10 °C), after a 3-min exercise bout, at 85% of VO2max,were examined in 10 swimmers. A pre-selected 40-s apnea, completed after rest (AAR), could not be met after exercise (AAE), and was terminated with an agonal gasp reflex, and a reduction of apneic time, by 75%. Bradycardia was evident with immersion after both, 40-s of AAR and after AAE (P<0.05). The dramatic elevation of, systolic pressure and pulse pressure, after AAE, were indicative of cardiovascular stress. Blood pressure after exercise without apnea was not equally elevated. The activation of neurally opposing functions as those elicited by the diving reflex after high intensity exercise may create an autonomic conflict possibly related to oxygen-conserving reflexes stimulated by the trigeminal nerve, and those elicited by exercise. Copyright © 2015. Published by Elsevier B.V.

Immersed radioactive wastes

International Nuclear Information System (INIS)

2017-03-01

This document presents a brief overview of immersed radioactive wastes worldwide: historical aspects, geographical localization, type of wastes (liquid, solid), radiological activity of immersed radioactive wastes in the NE Atlantic Ocean, immersion sites and monitoring

Immersive Learning Technologies

Science.gov (United States)

2009-08-20

Immersive Learning Technologies Mr. Peter Smith Lead, ADL Immersive Learning Team 08/20/2009 Report Documentation Page Form ApprovedOMB No. 0704...to 00-00-2009 4. TITLE AND SUBTITLE Immersive Learning Technologies 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR...unclassified c. THIS PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 Why Immersive Learning Technologies

Effect of immersion frequency on shoot multiplication of Bambusa vulgaris Schrader ex Wendland in RITA® TIS

Directory of Open Access Journals (Sweden)

Yudith García-Ramírez

2013-04-01

Full Text Available Bamboos are unique in bringing together a wide range of environmental services. The present work was conducted to determine the effect of immersion frequency of shoot multiplication of B. vulgaris grown in SIT. Three Immersion frequencies (every 4, 6 and 12 hours were studied. The plant height was measured and the number of shoots per explant and the number of expanded leaves per explant were quantified. Furthermore, the water content was determined in the explants. It was found that the immersion frequency influenced the in vitro multiplication of B. vulgaris. The results showed that the number of shoots (6.5 shoots / explant and the number of leaves per explant (11.0 leaves / explant were higher with immersion every six hours. The lowest values for all variables were found in explants cultured with immersion every 12 h. In this treatment water content in the explants was higher. The results indicated that with the management of the immersion frequency it can encourage the multiplication of B. vulgaris in SIT. Keywords: bamboo, in vitro propagation, water content

To cool, but not too cool: that is the question--immersion cooling for hyperthermia.

Science.gov (United States)

Taylor, Nigel A S; Caldwell, Joanne N; Van den Heuvel, Anne M J; Patterson, Mark J

2008-11-01

Patient cooling time can impact upon the prognosis of heat illness. Although ice-cold-water immersion will rapidly extract heat, access to ice or cold water may be limited in hot climates. Indeed, some have concerns regarding the sudden cold-water immersion of hyperthermic individuals, whereas others believe that cutaneous vasoconstriction may reduce convective heat transfer from the core. It was hypothesized that warmer immersion temperatures, which induce less powerful vasoconstriction, may still facilitate rapid cooling in hyperthermic individuals. Eight males participated in three trials and were heated to an esophageal temperature of 39.5 degrees C by exercising in the heat (36 degrees C, 50% relative humidity) while wearing a water-perfusion garment (40 degrees C). Subjects were cooled using each of the following methods: air (20-22 degrees C), cold-water immersion (14 degrees C), and temperate-water immersion (26 degrees C). The time to reach an esophageal temperature of 37.5 degrees C averaged 22.81 min (air), 2.16 min (cold), and 2.91 min (temperate). Whereas each of the between-trial comparisons was statistically significant (P < 0.05), cooling in temperate water took only marginally longer than that in cold water, and one cannot imagine that the 45-s cooling time difference would have any meaningful physiological or clinical implications. It is assumed that this rapid heat loss was due to a less powerful peripheral vasoconstrictor response, with central heat being more rapidly transported to the skin surface for dissipation. Although the core-to-water thermal gradient was much smaller with temperate-water cooling, greater skin and deeper tissue blood flows would support a superior convective heat delivery. Thus, a sustained physiological mechanism (blood flow) appears to have countered a less powerful thermal gradient, resulting in clinically insignificant differences in heat extraction between the cold and temperate cooling trials.

Masculinization of Nile tilapia (Oreochromis niloticus) by immersion in androgens

Science.gov (United States)

Gale, W.L.; Fitzpatrick, M.S.; Lucero, M.; Contreras-Sanchez, W.M.; Schreck, C. B.

1999-01-01

The use of all-male populations increases the efficiency and feasibility of tilapia aquaculture. The objective of this study was to determine the efficacy of a short-term immersion procedure for masculinizing Nile tilapia (Oreochromis niloticus). Two synthetic androgens were evaluated: 17α-methyldihydrotestosterone (MDHT) and 17α-methyltestosterone (MT). Exposure (3 h) on 10 and again on 13 days post-fertilization to MDHT at 500 μg/1 successfully masculinized fry in all experiments, resulting in 100, 94 and 83 ± 2% males in Experiments 1, 2 and 3, respectively. Immersions in MDHT or MT at 100 μg/1 resulted in significantly skewed sex ratios in Experiments 1 and 3 (MT resulted in 73 and 83 ± 3% males; and MDHT resulted in 72 and 91 ± 1% males) but not in Experiment 2. Immersion in MT at 500 μg/1 only caused masculinization in Experiment 3. Although further research and refinement is needed, immersion of Nile tilapia in MDHT may provide a practical alternative to the use of steroid-treated feed. Furthermore, when compared with current techniques for steroid-induced sex inversion of tilapia, short-term immersion reduces the period of time that workers are exposed to anabolic steroids.

Fluorescent layers for characterization of sectioning microscopy with coverslipuncorrected and water immersion objectives

KAUST Repository

Antonini, Andrea; Liberale, Carlo; Fellin, Tommaso

2014-01-01

We describe a new method to generate thin (thickness > 200 nm) and ultrathin (thickness < 200 nm) fluorescent layers to be used for microscope optical characterization. These layers are obtained by ultramicrotomy sectioning of fluorescent acrylic slides. This technique generates sub-resolution sheets with high fluorescence emission and uniform thickness, permitting to determine the z-response of different optical sectioning systems. Compared to the state of the art, the here proposed technique allows shorter and easier manufacturing procedure. Moreover, these fluorescent layers can be employed without protective coverslips, allowing the use of the Sectioned Imaging Property (SIP)-chart characterization method with coverslip-uncorrected objectives, water immersion objectives and micro-endoscopes. © 2014 Optical Society of America.

The validation of organ dose calculations using voxel phantoms and Monte Carlo methods applied to point and water immersion sources.

Science.gov (United States)

Hunt, J G; da Silva, F C A; Mauricio, C L P; dos Santos, D S

2004-01-01

The Monte Carlo program 'Visual Monte Carlo-dose calculation' (VMC-dc) uses a voxel phantom to simulate the body organs and tissues, transports photons through this phantom and reports the absorbed dose received by each organ and tissue relevant to the calculation of effective dose as defined in ICRP Publication 60. This paper shows the validation of VMC-dc by comparison with EGSnrc and with a physical phantom containing TLDs. The validation of VMC-dc by comparison with EGSnrc was made for a collimated beam of 0.662 MeV photons irradiating a cube of water. For the validation by comparison with the physical phantom, the case considered was a whole body irradiation with a point 137Cs source placed at a distance of 1 m from the thorax of an Alderson-RANDO phantom. The validation results show good agreement for the doses obtained using VMC-dc and EGSnrc calculations, and from VMC-dc and TLD measurements. The program VMC-dc was then applied to the calculation of doses due to immersion in water containing gamma emitters. The dose conversion coefficients for water immersion are compared with their equivalents in the literature.

The validation of organ dose calculations using voxel phantoms and Monte Carlo methods applied to point and water immersion sources

International Nuclear Information System (INIS)

Hunt, J. G.; Da Silva, F. C. A.; Mauricio, C. L. P.; Dos Santos, D. S.

2004-01-01

The Monte Carlo program 'Visual Monte Carlo-dose calculation' (VMC-dc) uses a voxel phantom to simulate the body organs and tissues, transports photons through this phantom and reports the absorbed dose received by each organ and tissue relevant to the calculation of effective dose as defined in ICRP Publication 60. This paper shows the validation of VMC-dc by comparison with EGSnrc and with a physical phantom containing TLDs. The validation of VMC-dc by comparison with EGSnrc was made for a collimated beam of 0.662 MeV photons irradiating a cube of water. For the validation by comparison with the physical phantom, the case considered was a whole body irradiation with a point 137 Cs source placed at a distance of 1 m from the thorax of an Alderson-RANDO phantom. The validation results show good agreement for the doses obtained using VMC-dc and EGSnrc calculations, and from VMC-dc and TLD measurements. The program VMC-dc was then applied to the calculation of doses due to immersion in water containing gamma emitters. The dose conversion coefficients for water immersion are compared with their equivalents in the literature. (authors)

Surface hardness evaluation of different composite resin materials: influence of sports and energy drinks immersion after a short-term period

Directory of Open Access Journals (Sweden)

Ugur Erdemir

2013-04-01

Full Text Available Objectives: This study evaluated the effect of sports and energy drinks on the surface hardness of different composite resin restorative materials over a 1-month period. Material and Methods: A total of 168 specimens: Compoglass F, Filtek Z250, Filtek Supreme, and Premise were prepared using a customized cylindrical metal mould and they were divided into six groups (N=42; n=7 per group. For the control groups, the specimens were stored in distilled water for 24 hours at 37°C and the water was renewed daily. For the experimental groups, the specimens were immersed in 5 mL of one of the following test solutions: Powerade, Gatorade, X-IR, Burn, and Red Bull, for two minutes daily for up to a 1-month test period and all the solutions were refreshed daily. Surface hardness was measured using a Vickers hardness measuring instrument at baseline, after 1-week and 1-month. Data were statistically analyzed using Multivariate repeated measure ANOVA and Bonferroni's multiple comparison tests (α=0.05. Results: Multivariate repeated measures ANOVA revealed that there were statistically significant differences in the hardness of the restorative materials in different immersion times (p<0.001 in different solutions (p<0.001. The effect of different solutions on the surface hardness values of the restorative materials was tested using Bonferroni's multiple comparison tests, and it was observed that specimens stored in distilled water demonstrated statistically significant lower mean surface hardness reductions when compared to the specimens immersed in sports and energy drinks after a 1-month evaluation period (p<0.001. The compomer was the most affected by an acidic environment, whereas the composite resin materials were the least affected materials. Conclusions: The effect of sports and energy drinks on the surface hardness of a restorative material depends on the duration of exposure time, and the composition of the material.

Cardiovascular responses to apneic facial immersion during altered cardiac filling.

Science.gov (United States)

Journeay, W Shane; Reardon, Francis D; Kenny, Glen P

2003-06-01

The hypothesis that reduced cardiac filling, as a result of lower body negative pressure (LBNP) and postexercise hypotension (PEH), would attenuate the reflex changes to heart rate (HR), skin blood flow (SkBF), and mean arterial pressure (MAP) normally induced by facial immersion was tested. The purpose of this study was to investigate the cardiovascular control mechanisms associated with apneic facial immersion during different cardiovascular challenges. Six subjects randomly performed 30-s apneic facial immersions in 6.0 +/- 1.2 degrees C water under the following conditions: 1) -20 mmHg LBNP, 2) +40 mmHg lower body positive pressure (LBPP), 3) during a period of PEH, and 4) normal resting (control). Measurements included SkBF at one acral (distal phalanx of the thumb) and one nonacral region of skin (ventral forearm), HR, and MAP. Facial immersion reduced HR and SkBF at both sites and increased MAP under all conditions (P filling during LBNP and PEH significantly attenuated the absolute HR nadir observed during the control immersion (P facial immersion can be attenuated when cardiac filling is compromised.

The Effectiveness of Whole Body Cryotherapy Compared to Cold Water Immersion: Implications for Sport and Exercise Recovery

Directory of Open Access Journals (Sweden)

Michael Holmes

2016-10-01

Full Text Available Background: Cryotherapy is the process of cooling the body, is typically used therapeutically, and is often used as a method of recovery relative to sport and exercise performance.  The purpose of this review is to compare the current literature on WBC to that of CWI and determine whether WBC provides any additional enhancements for sport and exercise recovery. These include tissue temperature reduction, markers of muscle damage, markers of inflammation, and parasympathetic reactivation. Method: Common methods of cryotherapy include cold water immersion (CWI, ice packs, ice massages, and gel or cooling creams. CWI is the most common method among athletes; however, a new form of cryotherapy, known as whole-body cryotherapy (WBC, has recently emerged.  Since its introduction, WBC has grown in popularity among practitioners and athletes. WBC involves short exposures (generally between 2-4 minutes to very cold air (-100o C to -140o C in a controlled room and setting. Furthermore, many of the studies on WBC were observational and did not contain a control group. Conclusion: Despite its growing popularity, the alleged benefits of WBC are largely based on anecdotal evidence as randomized, clinically-controlled studies regarding its efficacy are limited.  Keywords: cryotherapy, cold water immersion, exercise, recovery, muscle damage, inflammation

Immersive video

Science.gov (United States)

Moezzi, Saied; Katkere, Arun L.; Jain, Ramesh C.

1996-03-01

Interactive video and television viewers should have the power to control their viewing position. To make this a reality, we introduce the concept of Immersive Video, which employs computer vision and computer graphics technologies to provide remote users a sense of complete immersion when viewing an event. Immersive Video uses multiple videos of an event, captured from different perspectives, to generate a full 3D digital video of that event. That is accomplished by assimilating important information from each video stream into a comprehensive, dynamic, 3D model of the environment. Using this 3D digital video, interactive viewers can then move around the remote environment and observe the events taking place from any desired perspective. Our Immersive Video System currently provides interactive viewing and `walkthrus' of staged karate demonstrations, basketball games, dance performances, and typical campus scenes. In its full realization, Immersive Video will be a paradigm shift in visual communication which will revolutionize television and video media, and become an integral part of future telepresence and virtual reality systems.

Two strategies for response to 14 °C cold-water immersion: is there a difference in the response of motor, cognitive, immune and stress markers?

Directory of Open Access Journals (Sweden)

Marius Brazaitis

Full Text Available Here, we address the question of why some people have a greater chance of surviving and/or better resistance to cold-related-injuries in prolonged exposure to acute cold environments than do others, despite similar physical characteristics. The main aim of this study was to compare physiological and psychological reactions between people who exhibited fast cooling (FC; n = 20 or slow cooling (SC; n = 20 responses to cold water immersion. Individuals in whom the T(re decreased to a set point of 35.5 °C before the end of the 170-min cooling time were indicated as the FC group; individuals in whom the T(re did not decrease to the set point of 35.5 °C before the end of the 170-min cooling time were classified as the SC group. Cold stress was induced using intermittent immersion in bath water at 14 °C. Motor (spinal and supraspinal reflexes, voluntary and electrically induced skeletal muscle contraction force and cognitive (executive function, short term memory, short term spatial recognition performance, immune variables (neutrophils, leucocytes, lymphocytes, monocytes, IL-6, TNF-α, markers of hypothalamic-pituitary-adrenal axis activity (cortisol, corticosterone and autonomic nervous system activity (epinephrine, norepinephrine were monitored. The data obtained in this study suggest that the response of the FC group to cooling vs the SC group response was more likely an insulative-hypothermic response and that the SC vs the FC group displayed a metabolic-insulative response. The observations that an exposure time to 14 °C cold water--which was nearly twice as short (96-min vs 170-min with a greater rectal temperature decrease (35.5 °C vs 36.2 °C in the FC group compared with the SC group--induces similar responses of motor, cognitive, and blood stress markers were novel. The most important finding is that subjects with a lower cold-strain-index (SC group showed stimulation of some markers of innate immunity and suppression of markers of

Is water exchange superior to water immersion for colonoscopy? A systematic review and meta-analysis.

Science.gov (United States)

Chen, Zhihao; Li, Zhengqi; Yu, Xinying; Wang, Guiqi

2018-06-05

Recently, water exchange (WE) instead of water immersion (WI) for colonoscopy has been proposed to decrease pain and improve adenoma detection rate (ADR). This systematic review and meta-analysis is conducted to assess whether WE is superior to WI based on the published randomized controlled trials (RCTs). We searched studies from PubMed, Cochrane Central Register of Controlled Trials, EMBASE, and MEDLINE. Only RCTs were eligible for our study. The pooled risk ratios (RRs), pooled mean difference (MD), and pooled 95% confidence intervals (CIs) were calculated by using the fixed-effects model or random-effects model based on heterogeneity. Five RCTs consisting of 2229 colonoscopies were included in this study. WE was associated with a significantly higher ADR than WI (RR = 1.18; CI = 1.05-1.32; P = 0.004), especially in right colon (RR = 1.31; CI = 1.07-1.61; P = 0.01). Compared with WI, WE was confirmed with lower pain score, higher Boston Bowel Preparation Scale score, but more infused water during insertion. There was no statistical difference between WE and WI in cecal intubation rate and the number of patients who had willingness to repeat the examination. Furthermore, both total procedure time and cecal intubation time in WE were significantly longer than that in WI (MD = 2.66; CI = 1.42-3.90; P < 0.0001; vs MD = 4.58; CI = 4.01-5.15; P < 0.0001). This meta-analysis supports the hypothesis that WE is superior to WI in improving ADR, attenuating insertion pain and providing better bowel cleansing, but inferior in time and consumption of infused water consumption during insertion.

A simple water-immersion condenser for imaging living brain slices on an inverted microscope.

Science.gov (United States)

Prusky, G T

1997-09-05

Due to some physical limitations of conventional condensers, inverted compound microscopes are not optimally suited for imaging living brain slices with transmitted light. Herein is described a simple device that converts an inverted microscope into an effective tool for this application by utilizing an objective as a condenser. The device is mounted on a microscope in place of the condenser, is threaded to accept a water immersion objective, and has a slot for a differential interference contrast (DIC) slider. When combined with infrared video techniques, this device allows an inverted microscope to effectively image living cells within thick brain slices in an open perfusion chamber.

Comparison between cold water immersion therapy (CWIT) and light emitting diode therapy (LEDT) in short-term skeletal muscle recovery after high-intensity exercise in athletes--preliminary results.

Science.gov (United States)

Leal Junior, Ernesto Cesar; de Godoi, Vanessa; Mancalossi, José Luis; Rossi, Rafael Paolo; De Marchi, Thiago; Parente, Márcio; Grosselli, Douglas; Generosi, Rafael Abeche; Basso, Maira; Frigo, Lucio; Tomazoni, Shaiane Silva; Bjordal, Jan Magnus; Lopes-Martins, Rodrigo Alvaro Brandão

2011-07-01

In the last years, phototherapy has becoming a promising tool to improve skeletal muscle recovery after exercise, however, it was not compared with other modalities commonly used with this aim. In the present study we compared the short-term effects of cold water immersion therapy (CWIT) and light emitting diode therapy (LEDT) with placebo LEDT on biochemical markers related to skeletal muscle recovery after high-intensity exercise. A randomized double-blind placebo-controlled crossover trial was performed with six male young futsal athletes. They were treated with CWIT (5°C of temperature [SD ±1°]), active LEDT (69 LEDs with wavelengths 660/850 nm, 10/30 mW of output power, 30 s of irradiation time per point, and 41.7 J of total energy irradiated per point, total of ten points irradiated) or an identical placebo LEDT 5 min after each of three Wingate cycle tests. Pre-exercise, post-exercise, and post-treatment measurements were taken of blood lactate levels, creatine kinase (CK) activity, and C-reactive protein (CRP) levels. There were no significant differences in the work performed during the three Wingate tests (p > 0.05). All biochemical parameters increased from baseline values (p < 0.05) after the three exercise tests, but only active LEDT decreased blood lactate levels (p = 0.0065) and CK activity (p = 0.0044) significantly after treatment. There were no significant differences in CRP values after treatments. We concluded that treating the leg muscles with LEDT 5 min after the Wingate cycle test seemed to inhibit the expected post-exercise increase in blood lactate levels and CK activity. This suggests that LEDT has better potential than 5 min of CWIT for improving short-term post-exercise recovery.

Water/sand flooded and immersed critical experiment and analysis performed in support of the TOPAZ-II Safety Program

International Nuclear Information System (INIS)

Glushkov, E.S.; Ponomarev-Stepnoi, N.N.; Bubelev, V.G.; Garin, V.P.; Gomin, E.A.; Kompanietz, G.V.; Krutoy, A.M.; Lobynstev, V.A.; Maiorov, L.V.; Polyakov, D.N.

1994-01-01

Presented is a brief description of the Narciss-M2 critical assemblies, which simulate accidental water/wet-sand immersion of the TOPAZ-II reactor as well as water-flooding of core cavities. Experimental results obtained from these critical assemblies, including experiments with several fuel elements removed from the core, are shown. These configurations with several extracted fuel elements simulate a proposed fuel-out anticriticality-device modification to the TOPAZ-II reactor. Preliminary computational analysis of these experiments using the Monte Carlo neutron-transport method is outlined. Nuclear criticality safety of the TOPAZ-II reactor with an incorporated anticriticality unit is demonstrated

Simple and Green Fabrication of a Superhydrophobic Surface by One-Step Immersion for Continuous Oil/Water Separation.

Science.gov (United States)

Zhu, Jingfang; Liu, Bin; Li, Longyang; Zeng, Zhixiang; Zhao, Wenjie; Wang, Gang; Guan, Xiaoyan

2016-07-21

In this paper, stainless steel meshes with superhydrophobic and superoleophilic surfaces were fabricated by rapid and simple one-step immersion in a solution containing hydrochloric acid and stearic acid. The apparent contact angles were tested by a video contact angle measurement system (CA). Field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) were conducted to characterize the surface topographies and chemical compositions. The SEM results showed that mesh surfaces were covered by ferric stearate (Fe[CH3(CH2)16COO]2) with low surface energy. The CA test results showed that the mesh had a maximum apparent contact angle of 160 ± 1.0° and a sliding angle of less than 5.0° for the water droplet, whereas the apparent contact angle for the oil droplet was zero. Ultrasound oscillation and exposure tests at atmospheric conditions and immersion tests in 3.5 wt % NaCl aqueous solution were conducted to confirm the mesh with excellent superhydrophobic and superoleophilic properties. On the basis of the superhydrophobic mesh, a miniature separation device pump was designed to collect pure oil from the oil/water mixture. It showed that the device was easier and convenient. The techniques and materials presented in this work are promising for application to wastewater and oil spill treatment.

Supersymmetric versions of the Fokas–Gel’fand formula for immersion

International Nuclear Information System (INIS)

Bertrand, S; Grundland, A M

2016-01-01

In this paper, we construct and investigate two supersymmetric versions of the Fokas–Gel’fand formula for the immersion of 2D surfaces associated with a supersymmetric integrable system. The first version involves an infinitesimal deformation of the zero-curvature condition and the linear spectral problem associated with this system. This deformation leads the surfaces to be represented in terms of a bosonic supermatrix immersed in a Lie superalgebra. The second supersymmetric version is obtained by using a fermionic parameter deformation to construct surfaces expressed in terms of a fermionic supermatrix immersed in a Lie superalgebra. For both extensions, we provide a geometrical characterization of deformed surfaces using the super Killing form as an inner product and a super moving frame formalism. The theoretical results are applied to the supersymmetric sine-Gordon equation in order to construct super soliton surfaces associated with five different symmetries. We find integrated forms of these surfaces which represent constant Gaussian curvature surfaces and nonlinear Weingarten-type surfaces. (paper)

Water/sand flooded and immersed critical experiment and analysis performed in support of the TOPAZ-II safety program

International Nuclear Information System (INIS)

Glushkov, E.S.; Ponomarev-Stepnoi, N.N.; Bubelev, V.G.; Garin, V.P.; Gomin, E.A.; Kompanietz, G.V.; Krutov, A.M.; Lobynstev, V.A.; Maiorov, L.V.; Polyakov, D.N.; Chunyaev, E.I.; Marshall, A.C.; Sapir, J.L.; Pelowitz, D.B.

1995-01-01

Presented is a brief description of the Narciss-M2 critical assemblies, which simulate accidental water/wet-sand immersion of the TOPAZ-II reactor as well as water-flooding of core cavities. Experimental results obtained from these critical assemblies, including experiments with several fuel elements removed from the core, are shown. These configurations with several extracted fuel elements simulate a proposed fuel-out anticriticality-device modification to the TOPAZ-II reactor. Preliminary computational analysis of these experiments using the Monte Carlo neutron-transport method is outlined. Nuclear criticality safety of the TOPAZ-II reactor with an incorporated anticriticality unit is demonstrated. copyright 1995 American Institute of Physics

Effect of immersion time on in vitro multiplication of Bambusa vulgaris Schrader ex Wendland in RITA® TIS

Directory of Open Access Journals (Sweden)

Mallelyn González González

2013-01-01

Full Text Available The TIS provides solutions to the constraints that affecting in vitro propagation of bamboos and increases the quality of the plants in vitro propagated and survival of these in greenhouse conditions and field. This study aimed to determine the effect of immersion time on the multiplication of B. vulgaris shoot grown in TIS (RITA. Morphological, physiological and biochemical variables such as the number of shoots per plant, length of shoots, number of leaves per shoot, water contents, and lignin phenols were analyzed. It was demonstrated that the immersion time influenced the in vitro multiplication of B. vulgaris. The explants treated with the immersion time of a minute developed a greater number of shoots (5. These shoots showed dark green coloration, 92.1% water and 13% lignin. However, the increase of immersion time to three minutes caused increase in the water content of shoots and decreased lignin content, which affected their morphological response and multiplication in the TIS (RITA. Analysis of morphological, physiological and biochemical variables, allowed defining one minute is the optimum immersion time for shoot multiplication of B. vulgaris in temporary immersion systems (RITA. The method of in vitro propagation of B. vulgaris described offers the advantage of using liquid culture media and automated systems. Key words: bamboo, in vitro multiplication, morphological variables, temporal immersion systems

Effects of menthol application on the skin during prolonged immersion in swimmers and controls.

Science.gov (United States)

Botonis, P G; Geladas, N D; Kounalakis, S N; Cherouveim, E D; Koskolou, M D

2017-12-01

We hypothesized that menthol application on the skin would enhance vasoconstriction of subjects immersed in cool water, which would reduce heat loss and rectal temperature (Tre) cooling rate. Furthermore, it was hypothesized that this effect would be greater in individuals acclimatized to immersion in 24 °C water, such as swimmers. Seven swimmers (SW) and seven physical education students (CON) cycled at 60% VO 2 max until Tre attained 38 °C, and were then immediately immersed in stirred water maintained at 24 °C on two occasions: without (NM) and with (M; 4.6 g per 100 mL of water) whole-body skin application of menthol cream. Heart rate, Tre, proximal-distal skin temperature gradient, oxygen uptake (VO 2 ), electromyographic activity (EMG), and thermal sensation were measured. Tre reduction was similar among SW and CON in NM and CON in M (-0.71±0.31 °C in average), while it was smaller for SW in M (-0.37±0.18 °C, P immersion reduces heat loss, but defends Tre decline more effectively in swimmers than in non-swimmers. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Virtually numbed: immersive video gaming alters real-life experience.

Science.gov (United States)

Weger, Ulrich W; Loughnan, Stephen

2014-04-01

As actors in a highly mechanized environment, we are citizens of a world populated not only by fellow humans, but also by virtual characters (avatars). Does immersive video gaming, during which the player takes on the mantle of an avatar, prompt people to adopt the coldness and rigidity associated with robotic behavior and desensitize them to real-life experience? In one study, we correlated participants' reported video-gaming behavior with their emotional rigidity (as indicated by the number of paperclips that they removed from ice-cold water). In a second experiment, we manipulated immersive and nonimmersive gaming behavior and then likewise measured the extent of the participants' emotional rigidity. Both studies yielded reliable impacts, and thus suggest that immersion into a robotic viewpoint desensitizes people to real-life experiences in oneself and others.

Immersion hand radiography in the evaluation of musculoskeletal disorders

International Nuclear Information System (INIS)

Ngo, C.; Yaghmai, I.; Zach, R.

1987-01-01

A prospective study is undertaken to evaluate a new soft-tissue immersion technique. The hand is immersed in a plastic tray containing a mixture solution of alcohol and water. Exposures are made employing low-kilovolt technique. Conventional x-rays of the hands are obtained to serve as baseline studies and for the purpose of comparison. Soft-tissue immersion technique has proven sensitive and efficient in outlining the skin, subcutaneous fat layers, and fat layers between muscle planes. More importantly, the tendons and the joint capsules, which are hardly seen on standard hand radiographs, are easily highlighted with this technique. In conclusion, this technique appears to be superior to conventional plain radiographs in the evaluation and early detection of soft-tissue changes related to musculoskeletal disorders, especially in cases of arthritides

A vascular mechanism to explain thermally mediated variations in deep-body cooling rates during the immersion of profoundly hyperthermic individuals.

Science.gov (United States)

Caldwell, Joanne N; van den Heuvel, Anne M J; Kerry, Pete; Clark, Mitchell J; Peoples, Gregory E; Taylor, Nigel A S

2018-04-01

What is the central question of this study? Does the cold-water immersion (14°C) of profoundly hyperthermic individuals induce reductions in cutaneous and limb blood flow of sufficient magnitude to impair heat loss relative to the size of the thermal gradient? What is the main finding and its importance? The temperate-water cooling (26°C) of profoundly hyperthermic individuals was found to be rapid and reproducible. A vascular mechanism accounted for that outcome, with temperature-dependent differences in cutaneous and limb blood flows observed during cooling. Decisions relating to cooling strategies must be based upon deep-body temperature measurements that have response dynamics consistent with the urgency for cooling. Physiologically trivial time differences for cooling the intrathoracic viscera of hyperthermic individuals have been reported between cold- and temperate-water immersion treatments. One explanation for that observation is reduced convective heat delivery to the skin during cold immersion, and this study was designed to test both the validity of that observation, and its underlying hypothesis. Eight healthy men participated in four head-out water immersions: two when normothermic, and two after exercise-induced, moderate-to-profound hyperthermia. Two water temperatures were used within each thermal state: temperate (26°C) and cold (14°C). Tissue temperatures were measured at three deep-body sites (oesophagus, auditory canal and rectum) and eight skin surfaces, with cutaneous vascular responses simultaneously evaluated from both forearms (laser-Doppler flowmetry and venous-occlusion plethysmography). During the cold immersion of normothermic individuals, oesophageal temperature decreased relative to baseline (-0.31°C over 20 min; P immersed in cold rather than in temperate water (P immersion, whereas pronounced constriction was evident during both immersions when subjects were hyperthermic, with the colder water eliciting a greater vascular

Cryogenic immersion microscope

Science.gov (United States)

Le Gros, Mark; Larabell, Carolyn A.

2010-12-14

A cryogenic immersion microscope whose objective lens is at least partially in contact with a liquid reservoir of a cryogenic liquid, in which reservoir a sample of interest is immersed is disclosed. When the cryogenic liquid has an index of refraction that reduces refraction at interfaces between the lens and the sample, overall resolution and image quality are improved. A combination of an immersion microscope and x-ray microscope, suitable for imaging at cryogenic temperatures is also disclosed.

Research Paper: Effect of Lower Leg Cold Immersion on Dynamic Balance of Athletes and Nonathlete

Directory of Open Access Journals (Sweden)

Ruhollah Salehi

2016-07-01

Conclusion The results of this study suggest that cryotherapy through immersion of foot and ankle does not have a negative effect on the overall and anteroposterior indices of dynamic balance of athletes and nonathletes following an 8-min ice water immersion. It seems that the immersion process affected only the surface receptors of the skin and did not affect the deeper joint receptors that have a key role in balance.

Effect of immersion disinfection of alginate impressions in sodium hypochlorite solution on the dimensional changes of stone models.

Science.gov (United States)

Hiraguchi, Hisako; Kaketani, Masahiro; Hirose, Hideharu; Yoneyama, Takayuki

2012-01-01

This study investigated the effect of the immersion of alginate impressions in 0.5% sodium hypochlorite solution for 15 min on the dimensional changes of stone models designed to simulate a sectional form of a residual ridge. Five brands of alginate impression materials, which underwent various dimensional changes in water, were used. A stone model made with an impression that had not been immersed was prepared as a control. The immersion of two brands of alginate impressions that underwent small dimensional changes in water did not lead to serious deformation of the stone models, and the differences in the dimensional changes between the stone models produced with disinfected impressions and those of the control were less than 15 µm. In contrast, the immersions of three brands of alginate impressions that underwent comparatively large dimensional changes in water caused deformation of the stone models.

Immersed Boundary-Lattice Boltzmann Method Using Two Relaxation Times

Directory of Open Access Journals (Sweden)

Kosuke Hayashi

2012-06-01

Full Text Available An immersed boundary-lattice Boltzmann method (IB-LBM using a two-relaxation time model (TRT is proposed. The collision operator in the lattice Boltzmann equation is modeled using two relaxation times. One of them is used to set the fluid viscosity and the other is for numerical stability and accuracy. A direct-forcing method is utilized for treatment of immersed boundary. A multi-direct forcing method is also implemented to precisely satisfy the boundary conditions at the immersed boundary. Circular Couette flows between a stationary cylinder and a rotating cylinder are simulated for validation of the proposed method. The method is also validated through simulations of circular and spherical falling particles. Effects of the functional forms of the direct-forcing term and the smoothed-delta function, which interpolates the fluid velocity to the immersed boundary and distributes the forcing term to fixed Eulerian grid points, are also examined. As a result, the following conclusions are obtained: (1 the proposed method does not cause non-physical velocity distribution in circular Couette flows even at high relaxation times, whereas the single-relaxation time (SRT model causes a large non-physical velocity distortion at a high relaxation time, (2 the multi-direct forcing reduces the errors in the velocity profile of a circular Couette flow at a high relaxation time, (3 the two-point delta function is better than the four-point delta function at low relaxation times, but worse at high relaxation times, (4 the functional form of the direct-forcing term does not affect predictions, and (5 circular and spherical particles falling in liquids are well predicted by using the proposed method both for two-dimensional and three-dimensional cases.

But Do They Speak French? A Comparison of French Immersion Programs in Immersion Only and English/Immersion Settings. Research Report 79-01.

Science.gov (United States)

Parkin, Michael

Students' use of French in unsupervised classroom situations and outside the classroom was investigated in immersion center schools (all students are involved in French immersion programs) and dual track schools (French immersion programs co-exist with regular English language programs). A total of 414 students in grades 3 and 4 were observed…

Immersion Gratings for Infrared High-resolution Spectroscopy

Science.gov (United States)

Sarugaku, Yuki; Ikeda, Yuji; Kobayashi, Naoto; Kaji, Sayumi; Sukegawa, Takashi; Sugiyama, Shigeru; Nakagawa, Takao; Arasaki, Takayuki; Kondo, Sohei; Nakanishi, Kenshi; Yasui, Chikako; Kawakita, Hideyo

2016-10-01

High-resolution spectroscopy in the infrared wavelength range is essential for observations of minor isotopologues, such as HDO for water, and prebiotic organic molecules like hydrocarbons/P-bearing molecules because numerous vibrational molecular bands (including non-polar molecules) are located in this wavelength range. High spectral resolution enables us to detect weak lines without spectral line confusion. This technique has been widely used in planetary sciences, e.g., cometary coma (H2O, CO, and organic molecules), the martian atmosphere (CH4, CO2, H2O and HDO), and the upper atmosphere of gas giants (H3+ and organic molecules such as C2H6). Spectrographs with higher resolution (and higher sensitivity) still have a potential to provide a plenty of findings. However, because the size of spectrographs scales with the spectral resolution, it is difficult to realize it.Immersion grating (IG), which is a diffraction grating wherein the diffraction surface is immersed in a material with a high refractive index (n > 2), provides n times higher spectral resolution compared to a reflective grating of the same size. Because IG reduces the size of spectrograph to 1/n compared to the spectrograph with the same spectral resolution using a conventional reflective grating, it is widely acknowledged as a key optical device to realize compact spectrographs with high spectral resolution.Recently, we succeeded in fabricating a CdZnTe immersion grating with the theoretically predicted diffraction efficiency by machining process using an ultrahigh-precision five-axis processing machine developed by Canon Inc. Using the same technique, we completed a practical germanium (Ge) immersion grating with both a reflection coating on the grating surface and the an AR coating on the entrance surface. It is noteworthy that the wide wavelength range from 2 to 20 um can be covered by the two immersion gratings.In this paper, we present the performances and the applications of the immersion

Long-term water absorption and thickness swelling and determine their characteristics in wood flour/polypropylene/Nano SiO2 nanocomposite

Directory of Open Access Journals (Sweden)

Saeed Ismaeilimoghadam

2016-09-01

Full Text Available The objective of this study was to investigate the effect of nano SiO2 on long-term water absorption and thickness swelling, humidity coefficient diffusion and thickness swelling rate of wood plastic composite. For this purpose, 60% wood flour, 40% polypropylene, 2 per hundred compound (phc MAPP in internal mixer (HAAKE were mixed. Nano SiO2 with 0, 1, 3 and 5 (phc ratios as a reinforcing was used too. Finally test samples were fabricated by using the injection molding machine. Then long-term water absorption and thickness swelling for 1848 hours according to the ASTM standard on the samples were measured. Humidity coefficient diffusion and thickness swelling rate for closer look long-term water absorption and thickness swelling behavior in wood plastic nanocomposite were calculated too. For ensure to the formation of hydrogen bonds between hydroxyl grope of SiO2 nanoparticles with hydroxyl grope of wood flour form Fourier transform infrared (FTIR spectroscopy tests was used. The results showed that water absorption behavior of nanocomposite is according to Fick's law, in addition with increasing to SiO2 nanoparticles, long-term water absorption and thickness swelling and humidity coefficient diffusion in wood plastic nanocomposite decreased. The results of infrared spectroscopy showed that hydrogen bond between the nano SiO2 and wood flour confirmed. Statistical analysis showed that after 1848 hours of immersion, nano SiO2 showed a significant effect at a confidence level of 99% on water absorption and thickness swelling, so the sample with 5% silica nanoparticles was chosen as the best treatment.

Metabolic responses to prolonged work during treadmill and water immersion running.

Science.gov (United States)

Frangolias, D D; Rhodes, E C; Taunton, J E; Belcastro, A N; Coutts, K D

2000-12-01

The primary aim of this study was to compare the physiological responses to prolonged treadmill (TM) and water immersion to the neck (WI) running at threshold intensity. Ten endurance runners performed TM and WI running VO2max tests. Subjects completed submaximal performance tests at ventilatory threshold (Tvent) intensities under TM and WI conditions and responses at 15 and 42 minutes examined. VO2 was lower in WI (p<0.05) at maximal effort and Tvent. The Tvent VO2 intensities interpolated from the TM and WI VO2max tests were performed in both TM (i.e., TM@TM(tvent),TM@WI(tvent), corresponding to 77.6 and 71.3% respectively of TM VO2max) and WI conditions (i.e., WI@TM(tvent), WI@WI(tvent), corresponding to 85.5% and 78.2% respectively of WI VO2max). Each of the dependent variables was analyzed using a 3-way repeated measures ANOVA (2 conditions X 2 exercise intensities X 7 time points during exercise). VO2max values were significantly lower in the WI (52.4(5.1) ml.kg(-1) min(-1)) versus TM (59.7(6.5) ml.kg(-1) min(-1)) condition. VO2 during submaximal tests were similar during the TM and WI conditions. HR and [BLa] responses to exercise at and above WI(tvent) were similar during short-term exercise, but values tended to be lower during prolonged exercise in the WI condition. There were no statistical differences in VE responses in the 2 conditions, however as with HR and [BLa] an upward trend was noted with TM exercise over the 42 minute duration of the tests. RPE at WI(tvent) was similar for TM and WI exercise sessions, however, RPE at TM(tvent) was higher during WI compared to TM running. Cardiovascular drift was observed during prolonged TM but not WI running. Results suggest differences in metabolic responses to prolonged submaximal exercise in WI, however it can be used effectively for cross training.

Observation of skull-guided acoustic waves in a water-immersed murine skull using optoacoustic excitation

Science.gov (United States)

Estrada, Héctor; Rebling, Johannes; Razansky, Daniel

2017-02-01

The skull bone, a curved solid multilayered plate protecting the brain, constitutes a big challenge for the use of ultrasound-mediated techniques in neuroscience. Ultrasound waves incident from water or soft biological tissue are mostly reflected when impinging on the skull. To this end, skull properties have been characterized for both high-intensity focused ultrasound (HIFU) operating in the narrowband far-field regime and optoacoustic imaging applications. Yet, no study has been conducted to characterize the near-field of water immersed skulls. We used the thermoelastic effect with a 532 nm pulsed laser to trigger a wide range of broad-band ultrasound modes in a mouse skull. In order to capture the waves propagating in the near-field, a thin hydrophone was scanned in close proximity to the skull's surface. While Leaky pseudo-Lamb waves and grazing-angle bulk water waves are clearly visible in the spatio-temporal data, we were only able to identify skull-guided acoustic waves after dispersion analysis in the wavenumber-frequency space. The experimental data was found to be in a reasonable agreement with a flat multilayered plate model.

The immunostimulatory effects of hot-water extract of Gelidium amansii via immersion, injection and dietary administrations on white shrimp Litopenaeus vannamei and its resistance against Vibrio alginolyticus.

Science.gov (United States)

Fu, Yu-Win; Hou, Wen-Ying; Yeh, Su-Tuen; Li, Chiu-Hsia; Chen, Jiann-Chu

2007-06-01

The total haemocyte count (THC), phenoloxidase activity, and respiratory burst were examined when white shrimp Litopenaeus vannamei were immersed in seawater (34 per thousand) containing hot-water extract of red alga Gelidium amansii at 200, 400 and 600 mg l(-1), injected with hot-water extract at 4 and 6 microg g(-1) shrimp, and fed diets containing hot-water extract at 0, 0.5, 1.0 and 2.0 g kg(-1). These parameters increased significantly when shrimp were immersed in seawater containing hot-water extract at 400 and 600 mg l(-1) after 1h, when shrimp were injected with hot-water extract at 6 microg g(-1) shrimp after one day, and when shrimp were fed diets containing hot-water extract at 1.0 and 2.0 g kg(-1) after 14 days. Phagocytic activity and clearance efficiency were significantly higher for the shrimp that were fed diets containing hot-water extract at 1.0 and 2.0 g kg(-1) than those of shrimp that were fed diets containing hot-water extract at 0 and 0.5 g kg(-1) after 14 and 28 days. In a separate experiment, L. vannamei which had received hot-water extract via injection, or fed diets containing hot-water extract, were challenged after 3h or 28 days with V. alginolyticus at 2 x 10(6) cfu shrimp(-1) and 1 x 10(6) cfu shrimp(-1), respectively, and then placed in seawater. The survival of shrimp that were injected with hot-water extract at 6 microg g(-1) was significantly higher than that of control shrimp after 1 day, and the survival of shrimp fed diets containing hot-water extract at 0.5, 1.0 and 2.0 g kg(-1) increased significantly after 3 days as well as at the end of the experiment (6 days after the challenge), respectively. It was concluded that L. vannamei that were immersed in hot-water extract at 400 mg l(-1), injected with hot-water extract at 6 microg g(-1) shrimp, and fed hot-water extract of G. amansii at 2.0 g kg(-1) or less showed increased immune ability as well as resistance to V. alginolyticus infection.

Full-field optical coherence tomography using immersion Mirau interference microscope.

Science.gov (United States)

Lu, Sheng-Hua; Chang, Chia-Jung; Kao, Ching-Fen

2013-06-20

In this study, an immersion Mirau interference microscope was developed for full-field optical coherence tomography (FFOCT). Both the reference and measuring arms of the Mirau interferometer were filled with water to prevent the problems associated with imaging a sample in air with conventional FFOCT systems. The almost-common path interferometer makes the tomographic system less sensitive to environmental disturbances. En face OCT images at various depths were obtained with phase-shifting interferometry and Hariharan algorithm. This immersion interferometric method improves depth and quality in three-dimensional OCT imaging of scattering tissue.

Immersive journalism: immersive virtual reality for the first-person experience of news

OpenAIRE

Peña, Nonny de la; Weil, Peggy; Llobera, Joan; Giannopoulos, Elias; Pomés Freixa, Ausiàs; Spanlang, Bernhard; Friedman, Doron; Sánchez-Vives, María Victoria; Slater, Mel

2010-01-01

This paper introduces the concept, and discusses the implications of Immersive Journalism, that is the production of news in a form in which people can gain first- 2 person experiences of the events or situation described in news stories. The fundamental idea of Immersive Journalism is to allow the participant, typically represented as a digital avatar, to actually enter a virtually recreated scenario representing the news story. The sense of presence obtained through an immersive system (whe...

Is Learning in Low Immersive Environments Carried over to High Immersive Environments?

Directory of Open Access Journals (Sweden)

Dror David Lev

2012-01-01

Full Text Available One of the more debated issues regarding training simulators is their validity for transfer of skills to sensory environments that differ from the simulator. In two experiments, the advantages of three-dimensional (3D and collocated (Col visual displays were evaluated in a realistic and complex visuomotor task. The two factors were evaluated independently, comparing Col-2D with dislocated-2D (experiment 1 and with Col-3D (experiment 2. As expected, in both cases the more immersive presentation condition facilitated better performance. Furthermore, improvement following training in the more immersive condition carried over to the following less immersive condition but there was no carry over in the opposing order of presentation. This is taken as an indication for the differential development of skills conditioned by the level of immersiveness of the training environment. This further suggests that learning of complex realistic tasks is not carried over from less immersive simulator to the complex sensory environment of reality, due to the large gap in sensory patterns.

Photometric immersion refractometry of bacterial spores.

Science.gov (United States)

Gerhardt, P; Beaman, T C; Corner, T R; Greenamyre, J T; Tisa, L S

1982-01-01

Photometric immersion refractometry was used to determine the average apparent refractive index (n) of five types of dormant Bacillus spores representing a 600-fold range in moist-heat resistance determined as a D100 value. The n of a spore type increased as the molecular size of various immersion solutes decreased. For comparison of the spore types, the n of the entire spore and of the isolated integument was determined by use of bovine serum albumin, which is excluded from permeating into them. The n of the sporoplast (the structures bounded by the outer pericortex membrane) was determined by use of glucose, which was shown to permeate into the spore only as deeply as the pericortex membrane. Among the various spore types, an exponential increase in the heat resistance correlated with the n of the entire spore and of the sporoplast, but not of the isolated perisporoplast integument. Correlation of the n with the solids content of the entire spore provided a method of experimentally obtaining the refractive index increment (dn/dc), which was constant for the various spore types and enables the calculation of solids and water content from an n. Altogether, the results showed that the total water content is distributed unequally within the dormant spore, with less water in the sporoplast than in the perisporoplast integument, and that the sporoplast becomes more refractile and therefore more dehydrated as the heat resistance becomes greater among the various spore types. PMID:6802796

The impact of immersion protection requirements on hair dryer electrocutions in the USA.

Science.gov (United States)

Rodgers, Gregory B; Garland, Sarah

2012-12-01

To evaluate the effectiveness of the immersion protection requirements of a voluntary safety standard for portable handheld hair dryers in preventing electrocution deaths in the USA. The present work was an interrupted time series study design. Data on annual hair dryer-related electrocution deaths resulting from water contact were developed for the 1980-2007 study period. A multivariate Poisson regression model for rate data was used to evaluate the impact of the immersion protection requirements during the post-intervention period. The analysis controlled for the estimated number of hair dryers in use and the estimated number of US homes equipped with ground fault circuit interrupters, safety devices that would address hair dryer electrocutions even in the absence of the immersion protection requirements of the voluntary standard. The implementation of the 1987 and 1991 immersion protection requirements of the voluntary standard for portable handheld hair dryers was the intervention studied. The main outcome measure was the estimated reduction in the hair dryer electrocution rate associated with the immersion protection requirements of the voluntary standard. After controlling for covariates, the immersion protection requirements were estimated to reduce the rate of hair dryer immersion electrocution deaths by 96.6% (95% CI, 90.8% to 98.8%). This suggests the prevention of about 280 immersion electrocution deaths involving hair dryers during the post-intervention period (1987-2007). The immersion protection requirements of the voluntary safety standard for hair dryers have been highly effective in reducing hair dryer electrocutions.

Immersive CAD

Energy Technology Data Exchange (ETDEWEB)

Ames, A.L.

1999-02-01

This paper documents development of a capability for performing shape-changing editing operations on solid model representations in an immersive environment. The capability includes part- and assembly-level operations, with part modeling supporting topology-invariant and topology-changing modifications. A discussion of various design considerations in developing an immersive capability is included, along with discussion of a prototype implementation we have developed and explored. The project investigated approaches to providing both topology-invariant and topology-changing editing. A prototype environment was developed to test the approaches and determine the usefulness of immersive editing. The prototype showed exciting potential in redefining the CAD interface. It is fun to use. Editing is much faster and friendlier than traditional feature-based CAD software. The prototype algorithms did not reliably provide a sufficient frame rate for complex geometries, but has provided the necessary roadmap for development of a production capability.

Immersion in Movement-Based Interaction

NARCIS (Netherlands)

Pasch, M.; Bianchi-Berthouze, N.; van Dijk, Elisabeth M.A.G.; Nijholt, Antinus; Nijholt, A.; Reidsma, Dennis; Reidsma, D.; Hondorp, G.H.W.

2009-01-01

The phenomenon of immersing oneself into virtual environments has been established widely. Yet to date (to our best knowledge) the physical dimension has been neglected in studies investigating immersion in Human-Computer Interaction (HCI). In this paper we investigate how the concept of immersion

Effect of cow and soy milk on enamel hardness of immersed teeth

Science.gov (United States)

Widanti, H. A.; Herda, E.; Damiyanti, M.

2017-08-01

Cow milk and soy milk have different mineral contents and this can affect the tooth remineralization process. The aim of this study was to determine the effect of cow and soy milk on immersed teeth after demineralization. Twenty-one specimens, of human maxillary premolars, were measured for enamel hardness before immersion and demineralization in orange juice. The teeth were divided into three groups (n = 7) with each group immersed in either distilled water, cow milk, or soy milk. There was a significant increase in enamel hardness in all groups (p Cow milk provided the highest increase in enamel hardness, of all the three groups, but was not able to restore the initial enamel hardness.

Heterogeneous Ice Nucleation by Soufriere Hills Volcanic Ash Immersed in Water Droplets.

Directory of Open Access Journals (Sweden)

T P Mangan

Full Text Available Fine particles of ash emitted during volcanic eruptions may sporadically influence cloud properties on a regional or global scale as well as influencing the dynamics of volcanic clouds and the subsequent dispersion of volcanic aerosol and gases. It has been shown that volcanic ash can trigger ice nucleation, but ash from relatively few volcanoes has been studied for its ice nucleating ability. In this study we quantify the efficiency with which ash from the Soufriere Hills volcano on Montserrat nucleates ice when immersed in supercooled water droplets. Using an ash sample from the 11th February 2010 eruption, we report ice nucleating efficiencies from 246 to 265 K. This wide range of temperatures was achieved using two separate droplet freezing instruments, one employing nanolitre droplets, the other using microlitre droplets. Soufriere Hills volcanic ash was significantly more efficient than all other ash samples that have been previously examined. At present the reasons for these differences are not understood, but may be related to mineralogy, amorphous content and surface chemistry.

Heterogeneous Ice Nucleation by Soufriere Hills Volcanic Ash Immersed in Water Droplets.

Science.gov (United States)

Mangan, T P; Atkinson, J D; Neuberg, J W; O'Sullivan, D; Wilson, T W; Whale, T F; Neve, L; Umo, N S; Malkin, T L; Murray, B J

2017-01-01

Fine particles of ash emitted during volcanic eruptions may sporadically influence cloud properties on a regional or global scale as well as influencing the dynamics of volcanic clouds and the subsequent dispersion of volcanic aerosol and gases. It has been shown that volcanic ash can trigger ice nucleation, but ash from relatively few volcanoes has been studied for its ice nucleating ability. In this study we quantify the efficiency with which ash from the Soufriere Hills volcano on Montserrat nucleates ice when immersed in supercooled water droplets. Using an ash sample from the 11th February 2010 eruption, we report ice nucleating efficiencies from 246 to 265 K. This wide range of temperatures was achieved using two separate droplet freezing instruments, one employing nanolitre droplets, the other using microlitre droplets. Soufriere Hills volcanic ash was significantly more efficient than all other ash samples that have been previously examined. At present the reasons for these differences are not understood, but may be related to mineralogy, amorphous content and surface chemistry.

Evaluation of surface roughness of a nanofill resin composite after simulated brushing and immersion in mouthrinses, alcohol and water

Directory of Open Access Journals (Sweden)

Ana Carolina de Carvalho Rocha

2010-03-01

Full Text Available This study investigated the alteration of surface roughness of the nanofill composite Filtek Z350 3M/ESPE®, caused by simulated brushing associated with the use of mouthrinses with or without alcohol. Sixty specimens were prepared and distributed into six groups: distilled water, ethylic alcohol, Listerine® Vanilla Mint, Plax® without alcohol, Oral B® without alcohol and a control group. Each group was submitted to two intercalary 5,000 simulated brushing cycles. At the end of each cycle, the specimens were washed in tap water and immersed for two cycles of six hours equivalent to one year of daily use of the solution for 2 minutes. It was possible to verify significant alteration in surface roughness of the composite influenced by ethylic alcohol. It was not significant for distilled water and the mouthrinses.

Cold water recovery reduces anaerobic performance.

Science.gov (United States)

Crowe, M J; O'Connor, D; Rudd, D

2007-12-01

This study investigated the effects of cold water immersion on recovery from anaerobic cycling. Seventeen (13 male, 4 female) active subjects underwent a crossover, randomised design involving two testing sessions 2 - 6 d apart. Testing involved two 30-s maximal cycling efforts separated by a one-hour recovery period of 10-min cycling warm-down followed by either passive rest or 15-min cold water immersion (13 - 14 degrees C) with passive rest. Peak power, total work and postexercise blood lactate were significantly reduced following cold water immersion compared to the first exercise test and the control condition. These variables did not differ significantly between the control tests. Peak exercise heart rate was significantly lower after cold water immersion compared to the control. Time to peak power, rating of perceived exertion, and blood pH were not affected by cold water immersion compared to the control. Core temperature rose significantly (0.3 degrees C) during ice bath immersion but a similar increase also occurred in the control condition. Therefore, cold water immersion caused a significant decrease in sprint cycling performance with one-hour recovery between tests.

Cooling Effectiveness of a Modified Cold-Water Immersion Method After Exercise-Induced Hyperthermia.

Science.gov (United States)

Luhring, Katherine E; Butts, Cory L; Smith, Cody R; Bonacci, Jeffrey A; Ylanan, Ramon C; Ganio, Matthew S; McDermott, Brendon P

2016-11-01

 Recommended treatment for exertional heat stroke includes whole-body cold-water immersion (CWI). However, remote locations or monetary or spatial restrictions can challenge the feasibility of CWI. Thus, the development of a modified, portable CWI method would allow for optimal treatment of exertional heat stroke in the presence of these challenges.  To determine the cooling rate of modified CWI (tarp-assisted cooling with oscillation [TACO]) after exertional hyperthermia.  Randomized, crossover controlled trial.  Environmental chamber (temperature = 33.4°C ± 0.8°C, relative humidity = 55.7% ± 1.9%).  Sixteen volunteers (9 men, 7 women; age = 26 ± 4.7 years, height = 1.76 ± 0.09 m, mass = 72.5 ± 9.0 kg, body fat = 20.7% ± 7.1%) with no history of compromised thermoregulation.  Participants completed volitional exercise (cycling or treadmill) until they demonstrated a rectal temperature (T re ) ≥39.0°C. After exercise, participants transitioned to a semirecumbent position on a tarp until either T re reached 38.1°C or 15 minutes had elapsed during the control (no immersion [CON]) or TACO (immersion in 151 L of 2.1°C ± 0.8°C water) treatment.  The T re , heart rate, and blood pressure (reported as mean arterial pressure) were assessed precooling and postcooling. Statistical analyses included repeated-measures analysis of variance with appropriate post hoc t tests and Bonferroni correction.  Before cooling, the T re was not different between conditions (CON: 39.27°C ± 0.26°C, TACO: 39.30°C ± 0.39°C; P = .62; effect size = -0.09; 95% confidence interval [CI] = -0.2, 0.1). At postcooling, the T re was decreased in the TACO (38.10°C ± 0.16°C) compared with the CON condition (38.74°C ± 0.38°C; P < .001; effect size = 2.27; 95% CI = 0.4, 0.9). The rate of cooling was greater during the TACO (0.14 ± 0.06°C/min) than the CON treatment (0.04°C/min ± 0.02°C/min; t 15 = -8.84; P < .001; effect size = 2.21; 95% CI = -0.13, -0

Study on Concrete Containing Recycled Aggregates Immersed in Epoxy Resin

Directory of Open Access Journals (Sweden)

Adnan Suraya Hani

2017-01-01

Full Text Available In recent decades, engineers have sought a more sustainable method to dispose of concrete construction and demolition waste. One solution is to crush this waste concrete into a usable gradation for new concrete mixes. This not only reduces the amount of waste entering landfills but also alleviates the burden on existing sources of quality natural concrete aggregates. There are too many kinds of waste but here constructions waste will be the priority target that should be solved. It could be managed by several ways such as recycling and reusing the concrete components, and the best choice of these components is the aggregate, because of the ease process of recycle it. In addition, recycled aggregates and normal aggregates were immersed in epoxy resin and put in concrete mixtures with 0%, 5%, 10% and 20% which affected the concrete mixtures properties. The strength of the concrete for both normal and recycled aggregates has increased after immersed the aggregates in epoxy resin. The percentage of water absorption and the coefficient of water permeability decreased with the increasing of the normal and the recycled aggregates immersed in epoxy resin. Generally the tests which have been conducted to the concrete mixtures have a significant results after using the epoxy resin with both normal and recycled aggregates.

Beyond "Home-Like" Design: Visitor Responses to an Immersive Creative Space in a Canadian Long-Term Care Facility.

Science.gov (United States)

Graham, Megan E; Fabricius, Andréa

2017-11-01

This study examined the benefits of expanding upon the "home-like" design by introducing an immersive creative space for residents, staff, and visitors to explore in a long-term care facility in Eastern Ontario, Canada. Data were collected through guestbook comments ( N = 93) and coded for themes according to guidelines for thematic analysis. Selected themes included visitors' enjoyment of the winter aesthetic, expressions of gratitude to the artists, time spent socializing with family and visitors in a creative milieu, and the experience of remembering in an evocative space. The results indicate that residents and visitors benefited from the experience of a creative space that was neither institutional, nor "home-like." Implications for future research are discussed.

Towards evidence-based emergency medicine: best BETs from the Manchester Royal Infirmary. BET 3: In patients with heatstroke is whole-body ice-water immersion the best cooling method?

Science.gov (United States)

Newport, Matthew; Grayson, Alan

2012-10-01

A short cut review was carried out to establish whether whole body ice immersion was an effective way of cooling in patients presenting with heat stroke. One systematic review and three studies were directly relevant to the question. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of these papers are tabulated. The clinical bottom line was that immersion in ice-water was the most effective modality of lowering core body temperature in exertional heatstroke and shivering and vasoconstriction concerns were unfounded.

Long term integrity of reactor pressure vessel and primary containment vessel after the severe accidents in Fukushima Daiichi Nuclear Power Station. Leaching property of spent oxide fuel segment and corrosion property of a carbon steel under artificial seawater immersion

International Nuclear Information System (INIS)

2014-06-01

Primary containment vessel (PCV), reactor pressure vessel and pedestal in Fukushima Daiichi Nuclear power station units 1 through 3 have been exposed to severe thermal, chemical and mechanical conditions due to core meltdown events and seawater injections for emergent core cooling. These components will be immersed in diluted seawater with dissolved fission products under irradiation until the end of debris removal. Fresh water injected into the cores contacts with debris to cool, dissolves or erodes their constituents, mixed with retained water, and becomes 'accumulated water' with radioactive nuclides. We have focused the leaching of fission products into the accumulated water under lower temperature (323 K). FUGEN spent oxide fuel segments were immersed to determine the leaching factor of fission product and actinide elements. Since PCV made from carbon steel is one of the most important boundaries to prevent from fission products release, corrosion behavior has been paid attention to evaluate their integrity. Carbon steel specimens were immersion- and electrochemical-tested in diluted seawater with simulants of the accumulated water at 323 K in order to evaluate the effect of fission products in particular cesium and radiation. (author)

Physical characteristics cannot be used to predict cooling time using cold-water immersion as a treatment for exertional hyperthermia.

Science.gov (United States)

Poirier, Martin P; Notley, Sean R; Flouris, Andreas D; Kenny, Glen P

2018-03-12

We examined if physical characteristics could be used to predict cooling time during cold water immersion (CWI, 2°C) following exertional hyperthermia (rectal temperature ≥39.5°C) in a physically heterogeneous group of men and women (n=62). Lean body mass was the only significant predictor of cooling time following CWI (R2=0.137; P<0.001); however that prediction did not provide the precision (mean residual square error: 3.18±2.28 min) required to act as a safe alternative to rectal temperature measurements.

Hydroxyapatite coating on damaged tooth surfaces by immersion

International Nuclear Information System (INIS)

Lim, Byoung-Ki; Ryu, Su-Chak; Sun, Fangfang; Koh, Kwangnak; Han, Dong-Wook; Lee, Jaebeom

2009-01-01

Hydroxyapatite (HAp) was coated on scratched areas of a human tooth and HAp disks by the immersion method in a HAp colloidal solution (≤20 μm of average diameter dispersed in DI water). The surface morphologies of the scratched area after immersion for 1-3 months were investigated showing that the damaged surfaces were remarkably recovered. Then, the mechanical property and chemical stability of the HAp coating layers on both specimens were determined via the Vickers hardness test and concentration measurement of extracted Ca 2+ ions, respectively, after strong acidic treatment. The cellular behavior of mouse calvaria-derived pre-osteoblastic cells (MC3T3-E1) was also examined on the HAp layers regenerated on micro-scratched HAp disks for the purpose of their potential applications on maxillofacial bone conservation and reconstruction for prosthetic dentistry, and artificial disk preparation of a vertebral column. The notable loss of Ca 2+ ions under a highly acidic condition was not observed in the layers coated by HAp adsorption, indicating that the coating surface was well adhered with the original surfaces of the respective specimen. Moreover, the HAp adsorption did not adversely affect the adhesion, growth and proliferation of MC3T3-E1 cells on the coated HAp layers for up to 21 days. These results suggest that the HAp coating on the scratched areas of the tooth would be effectively applicable for the development of long-term prevention of micro-cleavage and tooth health supporters to reduce discoloration and further maxillofacial and orthopedic applications.

An immersed interface vortex particle-mesh solver

Science.gov (United States)

Marichal, Yves; Chatelain, Philippe; Winckelmans, Gregoire

2014-11-01

An immersed interface-enabled vortex particle-mesh (VPM) solver is presented for the simulation of 2-D incompressible viscous flows, in the framework of external aerodynamics. Considering the simulation of free vortical flows, such as wakes and jets, vortex particle-mesh methods already provide a valuable alternative to standard CFD methods, thanks to the interesting numerical properties arising from its Lagrangian nature. Yet, accounting for solid bodies remains challenging, despite the extensive research efforts that have been made for several decades. The present immersed interface approach aims at improving the consistency and the accuracy of one very common technique (based on Lighthill's model) for the enforcement of the no-slip condition at the wall in vortex methods. Targeting a sharp treatment of the wall calls for substantial modifications at all computational levels of the VPM solver. More specifically, the solution of the underlying Poisson equation, the computation of the diffusion term and the particle-mesh interpolation are adapted accordingly and the spatial accuracy is assessed. The immersed interface VPM solver is subsequently validated on the simulation of some challenging impulsively started flows, such as the flow past a cylinder and that past an airfoil. Research Fellow (PhD student) of the F.R.S.-FNRS of Belgium.

Criticality for Global Citizenship in Korean English Immersion Camps

Science.gov (United States)

Ahn, So-Yeon

2015-01-01

Given a heavy social, ideological pressure for parents to pursue better English education for their children in the globalized world, short-term English immersion camp programs have emerged as an educational option in South Korea, promoted as environments for intercultural communication between native English-speaking teachers and local Korean…

Embedding Versus Immersion in General Relativity

OpenAIRE

Monte, Edmundo M.

2009-01-01

We briefly discuss the concepts of immersion and embedding of space-times in higher-dimensional spaces. We revisit the classical work by Kasner in which he constructs a model of immersion of the Schwarzschild exterior solution into a six-dimensional pseudo-Euclidean manifold. We show that, from a physical point of view, this model is not entirely satisfactory since the causal structure of the immersed space-time is not preserved by the immersion.

Immersion Refractometry of Isolated Bacterial Cell Walls

Science.gov (United States)

Marquis, Robert E.

1973-01-01

Immersion-refractometric and light-scattering measurements were adapted to determinations of average refractive indices and physical compactness of isolated bacterial cell walls. The structures were immersed in solutions containing various concentrations of polymer molecules that cannot penetrate into wall pores, and then an estimate was made of the polymer concentration or the refractive index of the polymer solution in which light scattering was reduced to zero. Because each wall preparation was heterogeneous, the refractive index of the medium for zero light scattering had to be estimated by extrapolation. Refractive indices for walls suspended in bovine serum albumin solutions ranged from 1.348 for walls of the rod form of Arthrobacter crystallopoietes to 1.382 for walls of the teichoic acid deficient, 52A5 strain of Staphylococcus aureus. These indices were used to calculate approximate values for solids content per milliliter, and the calculated values agreed closely with those estimated from a knowledge of dextran-impermeable volumes per gram, dry weight, of the walls. When large molecules such as dextrans or serum albumin were used for immersion refractometry, the refractive indices obtained were for entire walls, including both wall polymers and wall water. When smaller molecules that can penetrate wall pores to various extents were used with Micrococcus lysodeikticus walls, the average, apparent refractive index of the structures increased as the molecular size of probing molecules was decreased. It was possible to obtain an estimate of 1.45 to 1.46 for the refractive index of wall polymers, predominantly peptidoglycans in this case, by extrapolating the curve for refractive index versus molecular radius to a value of 0.2 nm, the approximate radius of a water molecule. This relatively low value for polymer refractive index was interpreted as evidence in favor of the amorphous, elastic model of peptidoglycan structure and against the crystalline, rigid

Muscle Reaction Time During a Simulated Lateral Ankle Sprain After Wet-Ice Application or Cold-Water Immersion.

Science.gov (United States)

Thain, Peter K; Bleakley, Christopher M; Mitchell, Andrew C S

2015-07-01

Cryotherapy is used widely in sport and exercise medicine to manage acute injuries and facilitate rehabilitation. The analgesic effects of cryotherapy are well established; however, a potential caveat is that cooling tissue negatively affects neuromuscular control through delayed muscle reaction time. This topic is important to investigate because athletes often return to exercise, rehabilitation, or competitive activity immediately or shortly after cryotherapy. To compare the effects of wet-ice application, cold-water immersion, and an untreated control condition on peroneus longus and tibialis anterior muscle reaction time during a simulated lateral ankle sprain. Randomized controlled clinical trial. University of Hertfordshire human performance laboratory. A total of 54 physically active individuals (age = 20.1 ± 1.5 years, height = 1.7 ± 0.07 m, mass = 66.7 ± 5.4 kg) who had no injury or history of ankle sprain. Wet-ice application, cold-water immersion, or an untreated control condition applied to the ankle for 10 minutes. Muscle reaction time and muscle amplitude of the peroneus longus and tibialis anterior in response to a simulated lateral ankle sprain were calculated. The ankle-sprain simulation incorporated a combined inversion and plantar-flexion movement. We observed no change in muscle reaction time or muscle amplitude after cryotherapy for either the peroneus longus or tibialis anterior (P > .05). Ten minutes of joint cooling did not adversely affect muscle reaction time or muscle amplitude in response to a simulated lateral ankle sprain. These findings suggested that athletes can safely return to sporting activity immediately after icing. Further evidence showed that ice can be applied before ankle rehabilitation without adversely affecting dynamic neuromuscular control. Investigation in patients with acute ankle sprains is warranted to assess the clinical applicability of these interventions.

Complete spacelike immersions with topology

International Nuclear Information System (INIS)

Harris, S.G.

1988-01-01

A fairly large class of Lorentz manifolds is defined, called WH normal manifolds, which are approximately those for which timelike infinity is a single point. It is shown that, in such a space, an immersed spacelike hypersurface which is complete must, if it is self-intersecting, not achronal or proper, satisfy strong topological conditions; in particular, if the immersion is injective in the fundamental group, then the hypersurface must be closed, embedded and achronal (i.e. a partial Cauchy surface). WH normal spaces include products of any Riemannian manifold with Minkowski 1-space; in such space, a complete immersed spacelike hypersurface must be immersed as a covering space for the Riemannian factor. (author)

Residual volume on land and when immersed in water: effect on percent body fat.

Science.gov (United States)

Demura, Shinichi; Yamaji, Shunsuke; Kitabayashi, Tamotsu

2006-08-01

There is a large residual volume (RV) error when assessing percent body fat by means of hydrostatic weighing. It has generally been measured before hydrostatic weighing. However, an individual's maximal exhalations on land and in the water may not be identical. The aims of this study were to compare residual volumes and vital capacities on land and when immersed to the neck in water, and to examine the influence of the measurement error on percent body fat. The participants were 20 healthy Japanese males and 20 healthy Japanese females. To assess the influence of the RV error on percent body fat in both conditions and to evaluate the cross-validity of the prediction equation, another 20 males and 20 females were measured using hydrostatic weighing. Residual volume was measured on land and in the water using a nitrogen wash-out technique based on an open-circuit approach. In water, residual volume was measured with the participant sitting on a chair while the whole body, except the head, was submerged . The trial-to-trial reliabilities of residual volume in both conditions were very good (intraclass correlation coefficient > 0.98). Although residual volume measured under the two conditions did not agree completely, they showed a high correlation (males: 0.880; females: 0.853; P body fat computed using residual volume measured in both conditions was very good for both sexes (males: r = 0.902; females: r = 0.869, P body fat: -3.4 to 2.2% for males; -6.3 to 4.4% for females). We conclude that if these errors are of no importance, residual volume measured on land can be used when assessing body composition.

Effect of a surface sealant on the color stability of composite resins after immersion in staining solution.

Science.gov (United States)

Pedroso, Lauana Borges; Barreto, Luma Franciélle Cabreira; Miotti, Leonardo Lamberti; Nicoloso, Gabriel Ferreira; Durand, Leticia Brandão

2016-01-01

This study evaluated the influence of surface sealants on the color stability of 2 different composite resins after immersion in coffee. Four groups were created (n = 10): microhybrid composite, microhybrid with surface sealant, nanofilled composite, and nanofilled composite with surface sealant. Half of the specimens of each group were immersed in distilled water and half were immersed in coffee for 48 hours. Color was measured before and after immersion. Groups with surface sealants presented less color variation when compared with the groups without surface sealants. The nanofilled resin specimens presented the greatest color variation within the groups without sealant. The surface sealant positively influenced the color stability of composite resin specimens immersed in coffee. When surface sealant was not applied, the microhybrid specimens had better color stability than the nanofilled.

NARCISS critical stand experiments for studying the nuclear safety in accident water immersion of highly enriched uranium dioxide fuel elements

International Nuclear Information System (INIS)

Ponomarev-Stepnoj, N.N.; Glushkov, E.S.; Bubelev, V.G.

2005-01-01

A brief description of the Topaz-2 SNPS designed under scientific supervision of RRC KI in Russia, and of the NARCISS critical facility, is given. At the NARCISS critical facility, neutronic peculiarities and nuclear safety issues of the Topaz-2 system reactor were studied experimentally. This work is devoted to a detailed description of experiments on investigation of criticality safety in accident water immersion og highly enriched uranium dioxide fuel elements, performed at the NARCISS facility. The experiments were carried out at water-moderated critical assemblies with varying height, number, and spacing of fuel elements. The results obtained in the critical experiments, computational models of the investigated critical configurations, and comparison of the computational and experimental results are given [ru

Influence of surface sealant on the translucency of composite resin: effect of immersion time and immersion media

Directory of Open Access Journals (Sweden)

Patrícia Petromilli Nordi Sasso Garcia

2008-06-01

Full Text Available This study evaluated the effect of surface sealant on the translucency of composite resin immersed in different solutions. The study involved the following materials: Charisma, Fortify and coffee, Coca-Cola®, tea and artificial saliva as solutions. Sixty-four specimens (n = 8 were manufactured and immersed in artificial saliva at 37 ± 1 °C. Samples were immersed in the solutions for three times a day and re-immersed in artificial saliva until the translucency readings. The measurements were carried out at nine times: T1 - 24 hours after specimen preparation, T2 - 24 hours after immersion in the solutions, T3 - 48 hours and T4 to T9 - 7, 14, 21, 30, 60 and 90 days, respectively, after immersion. The translucency values were measured using a JOUAN device. The results were subjected to ANOVA and Tukey's test at 5%. The surface sealant was not able to protect the composite resin against staining, the coffee showed the strongest staining action, followed by tea and regarding immersion time, a significant alteration was noted in the translucency of composite resin after 21 days.

Comparison of the microhardness of primary and permanent teeth after immersion in two types of carbonated beverages.

Science.gov (United States)

Haghgou, Hamid R; Haghgoo, Roza; Asdollah, Fatemah Molla

2016-01-01

The consumption of carbonated beverages is one of the etiological factors that cause dental erosion. The purpose of this research was to compare changes in the microhardness of permanent and primary teeth after immersion in two types of carbonated beverages. This investigation was done on 30 healthy permanent molars and 30 healthy primary canines. Each group of primary and permanent teeth was subdivided into three groups of 10 teeth. The teeth was immersed in 40 ml of each of the three beverages for 5 min. One subgroup was immersed in water (as a control). The next was immersed in Lemon Delster and the last subgroup was immersed in Coca-Cola. The microhardness of enamel was measured using the Vickers method before and after immersion. Finally, the data was analyzed by paired t-test, one-way analysis of variance, and t-test. Microhardness reduction in the primary teeth was significant in both the Lemon Delster and Coca-Cola groups (P Coca-Cola and Lemon Delster caused a significant reduction of microhardness in tooth enamel. This reduction was greater in primary teeth than in permanent teeth, and was also greater after immersion in Coca-Cola than after immersion in Lemon Delster.

Vibration of an Offshore Structure Having the Form of a Hollow Column Partially Filled with Multiple Fluids and Immersed in Water

OpenAIRE

Lin, Hsien-Yuan; Lee, Jeng-Nan; Sung, Wen-Hao

2012-01-01

This paper employs the numerical assembly method (NAM) to determine the exact frequency-response amplitudes of an offshore structure such as piles or towers having the form of a hollow column filled with multiple fluids, immersed in water, carrying an eccentric tip mass supported by a translational spring and/or a rotational spring, and subjected to a harmonic force. The hollow column is modeled as a Bernoulli-Euler cantilever beam fixed at the bottom. For the case of zero harmonic force, the...

Comparison of Distal Limb Warming With Fluidotherapy and Warm Water Immersion for Mild Hypothermia Rewarming.

Science.gov (United States)

Kumar, Parveen; McDonald, Gerren K; Chitkara, Radhika; Steinman, Alan M; Gardiner, Phillip F; Giesbrecht, Gordon G

2015-09-01

The purpose of the study was to determine the effectiveness of Fluidotherapy rewarming through the distal extremities for mildly hypothermic, vigorously shivering subjects. Fluidotherapy is a dry heat modality in which cellulose particles are suspended by warm air circulation. Seven subjects (2 female) were cooled on 3 occasions in 8˚C water for 60 minutes, or to a core temperature of 35°C. They were then dried and rewarmed in a seated position by 1) shivering only; 2) Fluidotherapy applied to the distal extremities (46 ± 1°C, mean ± SD); or 3) water immersion of the distal extremities (44 ± 1°C). The order of rewarming followed a balanced design. Esophageal temperature, skin temperature, heart rate, oxygen consumption, and heat flux were measured. The warm water produced the highest rewarming rate, 6.1°C·h(-1), 95% CI: 5.3-6.9, compared with Fluidotherapy, 2.2°C·h(-1), 95% CI: 1.4-3.0, and shivering only, 2.0°C·h(-1), 95% CI: 1.2-2.8. The Fluidotherapy and warm water conditions increased skin temperature and inhibited shivering heat production, thus reducing metabolic heat production (166 ± 42 W and 181 ± 45 W, respectively), compared with shivering only (322 ± 142 W). Warm water provided a significantly higher net heat gain (398.0 ± 52 W) than shivering only (288.4 ± 115 W). Fluidotherapy was not as effective as warm water for rewarming mildly hypothermic subjects. Although Fluidotherapy is more portable and technically simpler, it provides a lower rate of rewarming that is similar to shivering only. It does help decrease shivering heat production, lowering energy expenditure and cardiac work, and could be considered in a hospital setting, if convenient. Copyright © 2015 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

FIJI: A Framework for the Immersion-Journalism Intersection

Directory of Open Access Journals (Sweden)

Gary M. Hardee

2017-07-01

Full Text Available As journalists experiment with developing immersive journalism—first-person, interactive experiences of news events—guidelines are needed to help bridge a disconnect between the requirements of journalism and the capabilities of emerging technologies. Many journalists need to better understand the fundamental concepts of immersion and the capabilities and limitations of common immersive technologies. Similarly, developers of immersive journalism works need to know the fundamentals that define journalistic professionalism and excellence and the key requirements of various types of journalistic stories. To address these gaps, we have developed a Framework for the Immersion-Journalism Intersection (FIJI. In FIJI, we have identified four domains of knowledge that intersect to define the key requirements of immersive journalism: the fundamentals of immersion, common immersive technologies, the fundamentals of journalism, and the major types of journalistic stories. Based on these key requirements, we have formally defined four types of immersive journalism that are appropriate for public dissemination. In this article, we discuss the history of immersive journalism, present the four domains and key intersection of FIJI, and provide a number of guidelines for journalists new to creating immersive experiences.

[Immersion pulmonary edema].

Science.gov (United States)

Desgraz, Benoît; Sartori, Claudio; Saubade, Mathieu; Héritier, Francis; Gabus, Vincent

2017-07-12

Immersion pulmonary edema may occur during scuba diving, snorke-ling or swimming. It is a rare and often recurrent disease, mainly affecting individuals aged over 50 with high blood pressure. However it also occurs in young individuals with a healthy heart. The main symptoms are dyspnea, cough and hemoptysis. The outcome is often favorable under oxygen treatment but deaths are reported. A cardiac and pulmonary assessment is necessary to evaluate the risk of recurrence and possible contraindications to immersion.

Hybrid immersed interface-immersed boundary methods for AC dielectrophoresis

International Nuclear Information System (INIS)

Hossan, Mohammad Robiul; Dillon, Robert; Dutta, Prashanta

2014-01-01

Dielectrophoresis, a nonlinear electrokinetic transport mechanism, has become popular in many engineering applications including manipulation, characterization and actuation of biomaterials, particles and biological cells. In this paper, we present a hybrid immersed interface–immersed boundary method to study AC dielectrophoresis where an algorithm is developed to solve the complex Poisson equation using a real variable formulation. An immersed interface method is employed to obtain the AC electric field in a fluid media with suspended particles and an immersed boundary method is used for the fluid equations and particle transport. The convergence of the proposed algorithm as well as validation of the hybrid scheme with experimental results is presented. In this paper, the Maxwell stress tensor is used to calculate the dielectrophoretic force acting on particles by considering the physical effect of particles in the computational domain. Thus, this study eliminates the approximations used in point dipole methods for calculating dielectrophoretic force. A comparative study between Maxwell stress tensor and point dipole methods for computing dielectrophoretic forces are presented. The hybrid method is used to investigate the physics of dielectrophoresis in microfluidic devices using an AC electric field. The numerical results show that with proper design and appropriate selection of applied potential and frequency, global electric field minima can be obtained to facilitate multiple particle trapping by exploiting the mechanism of negative dielectrophoresis. Our numerical results also show that electrically neutral particles form a chain parallel to the applied electric field irrespective of their initial orientation when an AC electric field is applied. This proposed hybrid numerical scheme will help to better understand dielectrophoresis and to design and optimize microfluidic devices

Photogrammetric Applications of Immersive Video Cameras

Science.gov (United States)

Kwiatek, K.; Tokarczyk, R.

2014-05-01

The paper investigates immersive videography and its application in close-range photogrammetry. Immersive video involves the capture of a live-action scene that presents a 360° field of view. It is recorded simultaneously by multiple cameras or microlenses, where the principal point of each camera is offset from the rotating axis of the device. This issue causes problems when stitching together individual frames of video separated from particular cameras, however there are ways to overcome it and applying immersive cameras in photogrammetry provides a new potential. The paper presents two applications of immersive video in photogrammetry. At first, the creation of a low-cost mobile mapping system based on Ladybug®3 and GPS device is discussed. The amount of panoramas is much too high for photogrammetric purposes as the base line between spherical panoramas is around 1 metre. More than 92 000 panoramas were recorded in one Polish region of Czarny Dunajec and the measurements from panoramas enable the user to measure the area of outdoors (adverting structures) and billboards. A new law is being created in order to limit the number of illegal advertising structures in the Polish landscape and immersive video recorded in a short period of time is a candidate for economical and flexible measurements off-site. The second approach is a generation of 3d video-based reconstructions of heritage sites based on immersive video (structure from immersive video). A mobile camera mounted on a tripod dolly was used to record the interior scene and immersive video, separated into thousands of still panoramas, was converted from video into 3d objects using Agisoft Photoscan Professional. The findings from these experiments demonstrated that immersive photogrammetry seems to be a flexible and prompt method of 3d modelling and provides promising features for mobile mapping systems.

Report on soil tests of the fill used in the Ozuki by-pass, Yamaguchi Prefecture. A report on tests of the effect of water immersion on the fill (coal mine waste) used in the Ozuki by-pass

Energy Technology Data Exchange (ETDEWEB)

1982-01-01

Samples of the fill (coal mine waste) used in the construction of the Ozuki by-pass were immersed in beakers of water for 15 and 30 day periods. After air drying, the particle size of the samples was measured and test of their liquid and plastic limits were carried out. The results of these tests and of the particle size measurements are reported. Immersion in water resulted in a 1.5% increase in clay content and an increase in the liquid limit. Likewise, the plasticity index increased from 4.3 to 8.3.

Research on evaluation techniques for immersive multimedia

Science.gov (United States)

Hashim, Aslinda M.; Romli, Fakaruddin Fahmi; Zainal Osman, Zosipha

2013-03-01

Nowadays Immersive Multimedia covers most usage in tremendous ways, such as healthcare/surgery, military, architecture, art, entertainment, education, business, media, sport, rehabilitation/treatment and training areas. Moreover, the significant of Immersive Multimedia to directly meet the end-users, clients and customers needs for a diversity of feature and purpose is the assembly of multiple elements that drive effective Immersive Multimedia system design, so evaluation techniques is crucial for Immersive Multimedia environments. A brief general idea of virtual environment (VE) context and `realism' concept that formulate the Immersive Multimedia environments is then provided. This is followed by a concise summary of the elements of VE assessment technique that is applied in Immersive Multimedia system design, which outlines the classification space for Immersive Multimedia environments evaluation techniques and gives an overview of the types of results reported. A particular focus is placed on the implications of the Immersive Multimedia environments evaluation techniques in relation to the elements of VE assessment technique, which is the primary purpose of producing this research. The paper will then conclude with an extensive overview of the recommendations emanating from the research.

Exploring the Effects of a Short-Term Spanish Immersion Program in a Postsecondary Setting

Science.gov (United States)

Miano, Alice A.; Bernhardt, Elizabeth B.; Brates, Vivian

2016-01-01

This article probes the extent to which postsecondary Spanish learners can substantively increase their knowledge of Spanish over a two-week period within a context of language and content instruction for four hours per day. The article considers the relationship of an immersion experience to upper-level literature and culture classes. Insights…

Story Immersion May Be Effective in Promoting Diet and Physical Activity in Chinese Children.

Science.gov (United States)

Wang, Jing Jing; Baranowski, Tom; Lau, Patrick W C; Buday, Richard; Gao, Yang

2017-04-01

To evaluate the effect of playing a health video game embedded with story immersion, Escape from Diab (Diab), on children's diet and physical activity (PA) and to explore whether children immersed in Diab had greater positive outcomes. Two groups, nonrandomized; 3 outcome assessments: at baseline, immediately after the game (post 1), and 8-10 weeks after the game (post 2). A total of 179 Chinese children aged 8-12 years. The treatment group played Diab; the control group received no intervention. Motivation; self-efficacy; preference for fruit, vegetables, water, and PA; as well as PA behavior. Adjusted changes to post 1 and post 2 by ANCOVA controlling for demographic and baseline variables. Children who played Diab had increased intrinsic motivation for fruit and water, self-efficacy for PA, and self-reported PA scores at post 1 (all P Children with higher immersion scores (above the median) had increased intrinsic motivation for fruit and water, and autonomous and controlled motivation for PA at post 1 (all P children's psychological correlates of diet and PA and PA behavior. However, its maintenance of effectiveness needs to be enhanced and mechanisms of change need to be investigated more thoroughly. Copyright © 2017 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

IL 7: Theoretical investigation of the ultrafast dissociation of ionized biomolecules immersed in water

International Nuclear Information System (INIS)

Vuilleumier, R.; Herve du Penhoat, M.A.; Politis, M.F.; Gaigeot, M.P.; Lopez-Tarifa, P.; Alcami, M.; Martin, F.; Tavernelli, I.

2010-01-01

We apply time-dependent density functional theory and Ehrenfest dynamics to investigate, at a molecular level, direct and indirect effects of ionising radiations in DNA, in the particular case of irradiation by swift heavy ions such as those used in hadron therapy. Molecular double ionisation arising from irradiation by swift heavy ions (about 10% of ionisation events by ions whose velocity is about the third of speed of light), as a primary event, though maybe less probable than other events resulting from the electronic cascading (for instance, electronic excitations, electron attachments), may be systematically more damageable (and more lethal), as supported by studies of damages created by K holes in DNA. In the past recent years, we have developed the modeling at the microscopic level of the early stages of the Coulomb explosion of DNA molecules immersed in liquid water that follows the irradiation by swift heavy ions. To that end, Time-Dependent Density Functional Theory molecular dynamics simulations (TD-DFT MD) have been developed where localised Wannier orbitals are propagated. This latter enables to separate molecular orbitals of each water molecule from the molecular orbitals of the biomolecule. We find that the double ionisation of one molecule of the liquid sample, either one water molecule from the solvent or the biomolecule, may both be responsible for the formation of an atomic oxygen as a direct consequence of the molecule Coulomb explosion. The chemical reactivity of the produced atomic oxygen with other radicals present in the medium will ultimately lead to chemical products that are harmful to DNA. We will review our theoretical methodology and results on the production of atomic oxygen as a result of the double ionisation of water or as a result of the double ionisation of the Uracil RNA base will be presented. (authors)

Benefit of warm water immersion on biventricular function in patients with chronic heart failure

Directory of Open Access Journals (Sweden)

Kardassis Dimitris

2009-07-01

Full Text Available Abstract Background Regular physical activity and exercise are well-known cardiovascular protective factors. Many elderly patients with heart failure find it difficult to exercise on land, and hydrotherapy (training in warm water could be a more appropriate form of exercise for such patients. However, concerns have been raised about its safety. The aim of this study was to investigate, with echocardiography and Doppler, the acute effect of warm water immersion (WWI and effect of 8 weeks of hydrotherapy on biventricular function, volumes and systemic vascular resistance. A secondary aim was to observe the effect of hydrotherapy on brain natriuretic peptide (BNP. Methods Eighteen patients [age 69 ± 8 years, left ventricular ejection fraction 31 ± 9%, peakVO2 14.6 ± 4.5 mL/kg/min] were examined with echocardiography on land and in warm water (34°C. Twelve of these patients completed 8 weeks of control period followed by 8 weeks of hydrotherapy twice weekly. Results During acute WWI, cardiac output increased from 3.1 ± 0.8 to 4.2 ± 0.9 L/min, LV tissue velocity time integral from 1.2 ± 0.4 to 1.7 ± 0.5 cm and right ventricular tissue velocity time integral from 1.6 ± 0.6 to 2.5 ± 0.8 cm (land vs WWI, p There was no change in the cardiovascular response or BNP after 8 weeks of hydrotherapy. Conclusion Hydrotherapy was well tolerated by all patients. The main observed cardiac effect during acute WWI was a reduction in heart rate, which, together with a decrease in afterload, resulted in increases in systolic and diastolic biventricular function. Although 8 weeks of hydrotherapy did not improve cardiac function, our data support the concept that exercise in warm water is an acceptable regime for patients with heart failure.

Modeling Wettability Variation during Long-Term Water Flooding

Directory of Open Access Journals (Sweden)

Renyi Cao

2015-01-01

Full Text Available Surface property of rock affects oil recovery during water flooding. Oil-wet polar substances adsorbed on the surface of the rock will gradually be desorbed during water flooding, and original reservoir wettability will change towards water-wet, and the change will reduce the residual oil saturation and improve the oil displacement efficiency. However there is a lack of an accurate description of wettability alternation model during long-term water flooding and it will lead to difficulties in history match and unreliable forecasts using reservoir simulators. This paper summarizes the mechanism of wettability variation and characterizes the adsorption of polar substance during long-term water flooding from injecting water or aquifer and relates the residual oil saturation and relative permeability to the polar substance adsorbed on clay and pore volumes of flooding water. A mathematical model is presented to simulate the long-term water flooding and the model is validated with experimental results. The simulation results of long-term water flooding are also discussed.

Absorption of /sup 45/Ca during the immersion of the aerial organs of Salicornia stricta

Energy Technology Data Exchange (ETDEWEB)

Langlois, J.; Vilquin, A.

1971-04-01

Immersion of the aerial organs of Salicornia stricta in a nutrient solution with added radioactive /sup 45/Ca resulted in the accumulation of /sup 45/Ca in the aerial organs. There was no accumulation when the roots were immersed in the nutrient solution. Absorption of minerals by the stems and leaves of Salicornia during periodic submersions in the brackish water surrounding the plants, is therefore possible. 17 references, 1 figure, 1 table.

Effect of hemorrhage on cardiac output, vasopressin, aldosterone, and diuresis during immersion in men

Science.gov (United States)

Greenleaf, J. E.; Simanonok, K.; Bernauer, E. M.; Wade, C. E.; Keil, L. C.

1992-01-01

The purpose of this research was to test the hypotesis that a reduction in blood volume would attenuate or eliminate immersion-induced increases in cardiac output (Q(sub co)) and urine excretion, and to investigate accompanying vasoactive and fluid-electrolyte hormonal responses. Eight men (19-23 yr) were supine during a 2-hr control period in air, and then sat for 5-hr test periods in air at 20 C (dry control, DC); water at 34.5 C (wet control, WC); and water (34.5 C) after hemorrhage (WH) of 14.8 plus or minus 0.3 percent of their blood volume. Blood volume was -11.6 plus or minus 0.6 percent at immersion (time 0). Mean (bar-X hrs 1-5) Q(sub co) was unchanged in WC (5.3 plus or minus 0.01 l/min) and in WH (4.5 plus or minus 0.1 l/min), but decreased (P less than 0.05) in DC to 3.6 plus or minus 0.1 l/min. Mean urine excretion rates were 1.0 plus or minus 0.2 ml/min for DC and 1.1 plus or minus 0.2 ml/min for WH; both were lower (P less than 0.05) than that for WC of 2.0 plus or minus 0.4 ml/min. Plasma (Na+) and (Osm) were unchanged in all experiments. Mean plasma vasopressin (PVP) (bar-X hrs 1-5) was 1.1 plus or minus 0.1 pg/ml in WC, and higher (P less than 0.05) in DC (2.1 plus or minus 0.2 pg/ml)and WH (2.1 plus or minus 0.1 pg/ml); it was unchanged during air and water test periods. Thus, hemorrhage attenuated the immersion-induced increase in Q(sub co), eliminated the WC diuresis, maintained plasma renin activity and PVP at DC levels and did not change immersion-induced aldosterone suppression; the osmotic diuresis during control immersion is apparently not due to either aldosterone suppression or vasopressin suppression.

Enhancing the solar still using immersion type water heater productivity and the effect of external cooling fan in winter

International Nuclear Information System (INIS)

Al-Garni, Ahmed Z.

2012-01-01

In the present work an attempt is made to enhance the of double slope solar still productivity by an immersion type water heater using. The effect of using an external fan to cool the glass surface is also examined. Experiments were carried out for winter season in Saudi Arabian climatic conditions at latitude 26 degree N. A solar still with 35 degree glass slope angle is chosen in our study. Since the yield of a solar still is more for low water depths, the water level in the base tank was maintained at 1 cm. The experimental results showed that the productivity increased by a significant 370% when two water heaters each having 500 W capacities was used. When external cooling fan was used the productivity was found to decrease by 4 % and 8% for wind speeds of 7 m/s and 9 m/s respectively. Thermal modeling was also done by the heat and mass transfer relations using, and then numerical simulations were carried out to validate with the experimental results. A good agreement between experimental and numerical results was found. The present study is partial implementation of two patents submitted in this field. (authors)

Interaction with virtual crowd in Immersive and semi‐Immersive Virtual Reality systems

OpenAIRE

Kyriakou, Marios; Pan, Xueni; Chrysanthou, Yiorgos

2016-01-01

This study examines attributes of virtual human behavior that may increase the plausibility of a simulated crowd and affect the user's experience in Virtual Reality. Purpose-developed experiments in both Immersive and semi-Immersive Virtual Reality systems queried the impact of collision and basic interaction between real-users and the virtual crowd and their effect on the apparent realism and ease of navigation within Virtual Reality (VR). Participants' behavior and subjective measurements i...

Imersão em água fria para o manejo da hipertermia severa Cold water immersion to the control of exertional heat illness

Directory of Open Access Journals (Sweden)

Jacqueline de Paula Viveiros

2009-08-01

Full Text Available A incapacidade de dissipar o calor gerado pela atividade muscular prejudica o desempenho e aumenta a predisposição a lesões do organismo. A hipertermia severa induzida pelo esforço físico (HTE prejudica a saúde e está associada à morbidade e mortalidade de indivíduos em diferentes atividades ocupacionais e atléticas. Estudos sobre a eficiência de métodos de resfriamento corporal têm recomendado a imersão em água fria para o tratamento da HTE. Sua utilização nos minutos iniciais pós-hipertemia parece a melhor recomendação por reduzir o tempo no qual a temperatura central permanece elevada. A manutenção de infraestrutura necessária para a realização desse procedimento deve ser considerada em atividades físicas e condições ambientais nas quais os indivíduos estão mais suscetíveis ao acometimento da HTE. As taxas de resfriamento observadas através da imersão em água a diferentes temperaturas podem servir de referência para o controle da duração do procedimento. Esta revisão analisa a recomendação da imersão em água fria como procedimento de resfriamento corporal para o manejo da HTE.The incapacity of dissipating heat generated by muscular activity hampers performance and increases predisposition to physical injuries. Exertional heat illness (HTE harms health and is associated with morbidity and mortality of individuals in different occupational and athletic activities. Studies on the efficiency of body cooling methods have recommended cold-water immersion for the treatment of HTE. Its use in the initial minutes of post-hyperthermia seems to be the best recommendation to reduce the time central temperature remains high. Maintenance of the infrastructure needed to perform this procedure should be considered in physical activities and environmental conditions in which the individuals are more prone to HTE. The cooling rates observed through water immersion in different water temperatures may serve as reference

Immersion in Movement-Based Interaction

Science.gov (United States)

Pasch, Marco; Bianchi-Berthouze, Nadia; van Dijk, Betsy; Nijholt, Anton

The phenomenon of immersing oneself into virtual environments has been established widely. Yet to date (to our best knowledge) the physical dimension has been neglected in studies investigating immersion in Human-Computer Interaction (HCI). In movement-based interaction the user controls the interface via body movements, e.g. direct manipulation of screen objects via gestures or using a handheld controller as a virtual tennis racket. It has been shown that physical activity affects arousal and that movement-based controllers can facilitate engagement in the context of video games. This paper aims at identifying movement features that influence immersion. We first give a brief survey on immersion and movement-based interfaces. Then, we report results from an interview study that investigates how users experience their body movements when interacting with movement-based interfaces. Based on the interviews, we identify four movement-specific features. We recommend them as candidates for further investigation.

Comparing contact and immersion freezing from continuous flow diffusion chambers

Directory of Open Access Journals (Sweden)

B. Nagare

2016-07-01

process that is enhanced compared to immersion freezing due to the position of the INP on the droplet, and we discriminate it from collisional contact freezing, which assumes an enhancement due to the collision of the particle with the droplet. For best comparison with contact freezing results, immersion freezing experiments of the same INPs were performed with the continuous flow diffusion chamber Immersion Mode Cooling chAmber–Zurich Ice Nucleation Chamber (IMCA–ZINC for a 3 s residence time. In IMCA–ZINC, each INP is activated into a droplet in IMCA and provides its surface for ice nucleation in the ZINC chamber. The comparison of contact and immersion freezing results did not confirm a general enhancement of freezing efficiency for contact compared with immersion freezing experiments. For AgI particles the onset of heterogeneous freezing in CLINCH was even shifted to lower temperatures compared with IMCA–ZINC. For ATD, freezing efficiencies for contact and immersion freezing experiments were similar. For kaolinite particles, contact freezing became detectable at higher temperatures than immersion freezing. Using contact angle information between water and the INP, it is discussed how the position of the INP in or on the droplets may influence its ice nucleation activity.

Immersion lithography defectivity analysis at DUV inspection wavelength

Science.gov (United States)

Golan, E.; Meshulach, D.; Raccah, N.; Yeo, J. Ho.; Dassa, O.; Brandl, S.; Schwarz, C.; Pierson, B.; Montgomery, W.

2007-03-01

Significant effort has been directed in recent years towards the realization of immersion lithography at 193nm wavelength. Immersion lithography is likely a key enabling technology for the production of critical layers for 45nm and 32nm design rule (DR) devices. In spite of the significant progress in immersion lithography technology, there remain several key technology issues, with a critical issue of immersion lithography process induced defects. The benefits of the optical resolution and depth of focus, made possible by immersion lithography, are well understood. Yet, these benefits cannot come at the expense of increased defect counts and decreased production yield. Understanding the impact of the immersion lithography process parameters on wafer defects formation and defect counts, together with the ability to monitor, control and minimize the defect counts down to acceptable levels is imperative for successful introduction of immersion lithography for production of advanced DR's. In this report, we present experimental results of immersion lithography defectivity analysis focused on topcoat layer thickness parameters and resist bake temperatures. Wafers were exposed on the 1150i-α-immersion scanner and 1200B Scanner (ASML), defect inspection was performed using a DUV inspection tool (UVision TM, Applied Materials). Higher sensitivity was demonstrated at DUV through detection of small defects not detected at the visible wavelength, indicating on the potential high sensitivity benefits of DUV inspection for this layer. The analysis indicates that certain types of defects are associated with different immersion process parameters. This type of analysis at DUV wavelengths would enable the optimization of immersion lithography processes, thus enabling the qualification of immersion processes for volume production.

Effect of aspect ratio on natural convective heat transfer adjacent to a vertival isothermal cylinder immersed in pure water

International Nuclear Information System (INIS)

Riu, Kap Jong; Eum, Yong Kyoon; Park, Sung Soon

1990-01-01

A numerical analysis is performed about the effect of aspect ratio on heat transfer adjacent to a vertical-isothermal cylinder of 0 deg C in pure water. The numerical results for the effect of aspect ratio are presented for ambient water temperature from 1.0 deg C to 15.0 deg C. They include velocity profiles, temperature profiles and mean Nusselt number for the entire flow field. The mean Nusselt numbers of vertival-isothermal cylinder are compared with that of vertival-isothermal plate in increasing aspect ratio of cylinder. Furthermore, the mean Nusselt numbers of unsteady region in the range of 0.084< R<0.328 are obtained by curve-fitting. The natural convection caused by phase change was investigated by experiments when the vertical ice cylinder was immersed in the pure water of which the tempetature range is from 2.0 to 10.0 deg C. Each figure shows a time-exposure photograph of flow occuring at the respective ambient water temperature conditions. As the ambient water temperature is increased from 2.0 to 10.0 deg C, the regimes of upward steady state flows, steady state dual flows and downward steady state flows are observed. Also, the variations of shapes of melting ice cylinder are investigated.(Author)

Color Stability Assessment of Two Different Composite Resins with Variable Immersion Time Using Various Beverages: An In vitro Study.

Science.gov (United States)

Kumar, M Senthil; Ajay, R; Miskeen Sahib, S A; Chittrarasu, M; Navarasu, M; Ragavendran, N; Burhanuddin Mohammed, Omar Farooq

2017-11-01

The aim of the study was to evaluate the difference in the color of microhybrid (MH) and nanofilled (NF) composite resins after 24 and 48 h in beverages such as red wine (RW), Coca-Cola, and distilled water. The specific objective of this study was to investigate the cumulative effect of the colorant solutions on the dental composites. MH and NF composite resins (A2 shade) were used in this current study. Sixty disk-shaped material specimens (10 mm in diameter × 2 mm in thickness) were prepared using a fiber mold (ring), with the desired dimensions. The specimen surfaces were polished using super-snap polishing system. Sixty specimens were divided into two groups of 30 each (Group I: MH resin composite; Group II: NF resin composite). Both the groups divided into six subgroups (Subgroup I: RW for 24 h [RW-24]; Subgroup II: RW for 48 h; Subgroup III: Coca-Cola for 24 h [CC-24]; Subgroup IV: Coca-Cola for 48 h [CC-48]; Subgroup V: Distilled water for 24 h [DW-24]; Subgroup VI: Distilled water for 48 h [DW-48]). All the samples were immersed in respective drinks for a period of 24 h, and color differences were measured using ultraviolet spectrophotometer. Once again, all the samples were immersed for another 24 h in the same drinks. After 48 h, the color change of the samples was measured. Measurements were made according to the CIE L × a × b × color space relative to the CIE standard illuminant D65. The color changes of the specimens were evaluated using the following formula: Statistical analysis was performed. The data were analyzed using the one-way ANOVA and t -test at a significance level of 0.05. Color stability of MH composite resin was found to be inferior than the NF resin composite irrespective of immersion medium and time. In RW, the color change observed was maximum for both composite resins followed by Coca-Cola. Immersing the resin composites in distilled water for 24 and 48 h had negligible color change. A 48-h immersion of both composite resins in

Water Absorption Behavior of Hemp Hurds Composites

Science.gov (United States)

Stevulova, Nadezda; Cigasova, Julia; Purcz, Pavol; Schwarzova, Ivana; Kacik, Frantisek; Geffert, Anton

2015-01-01

In this paper, water sorption behavior of 28 days hardened composites based on hemp hurds and inorganic binder was studied. Two kinds of absorption tests on dried cube specimens in deionized water bath at laboratory temperature were performed. Short-term (after one hour water immersion) and long-term (up to 180 days) water absorption tests were carried out to study their durability. Short-term water sorption behavior of original hemp hurds composites depends on mean particle length of hemp and on binder nature. The comparative study of long-term water sorption behavior of composites reinforced with original and chemically modified hemp hurds in three reagents confirmed that surface treatment of filler influences sorption process. Based on evaluation of sorption curves using a model for composites based on natural fibers, diffusion of water molecules in composite reinforced with original and chemically modified hemp hurds is anomalous in terms of the Fickian behavior. The most significant decrease in hydrophility of hemp hurds was found in case of hemp hurds modified by NaOH and it relates to change in the chemical composition of hemp hurds, especially to a decrease in average degree of cellulose polymerization as well as hemicellulose content.

A second order penalized direct forcing for hybrid Cartesian/immersed boundary flow simulations

International Nuclear Information System (INIS)

Introini, C.; Belliard, M.; Fournier, C.

2014-01-01

In this paper, we propose a second order penalized direct forcing method to deal with fluid-structure interaction problems involving complex static or time-varying geometries. As this work constitutes a first step toward more complicated problems, our developments are restricted to Dirichlet boundary condition in purely hydraulic context. The proposed method belongs to the class of immersed boundary techniques and consists in immersing the physical domain in a Cartesian fictitious one of simpler geometry on fixed grids. A penalized forcing term is added to the momentum equation to take the boundary conditions around/inside the obstacles into account. This approach avoids the tedious task of re-meshing and allows us to use fast and accurate numerical schemes. In contrary, as the immersed boundary is described by a set of Lagrangian points that does not generally coincide with those of the Eulerian grid, numerical procedures are required to reconstruct the velocity field near the immersed boundary. Here, we develop a second order linear interpolation scheme and we compare it to a simpler model of order one. As far as the governing equations are concerned, we use a particular fractional-step method in which the penalized forcing term is distributed both in prediction and correction equations. The accuracy of the proposed method is assessed through 2-D numerical experiments involving static and rotating solids. We show in particular that the numerical rate of convergence of our method is quasi-quadratic. (authors)

Protective effect of epigallocatechin gallate in murine water-immersion stress model of chronic fatigue syndrome.

Science.gov (United States)

Sachdeva, Anand Kamal; Kuhad, Anurag; Tiwari, Vinod; Arora, Vipin; Chopra, Kanwaljit

2010-06-01

Chronic fatigue syndrome (CFS) is a specific clinical condition that characterizes unexplained disabling fatigue. In the present study, chronic fatigue was produced in mice by subjecting them to forced swim inside a rectangular jar of specific dimensions for 6 min. daily for 15 days. Epigallocatechin gallate (EGCG; 25, 50 and 100 mg/kg, p.o.) was administered daily 30 min. before forced swim session. Immobility period and post-swim fatigue was assessed on alternate days. On the 16th day, after assessment of various behavioural parameters, mice were killed to harvest the brain, spleen and thymus. There was significant increase in oxidative-nitrosative stress and tumour necrosis factor-alpha levels in the brain of mice subjected to water-immersion stress as compared with naive group. These behavioural and biochemical alterations were restored after chronic treatment with EGCG. The present study points out that EGCG could be of therapeutic potential in the treatment of chronic fatigue.

Cold water immersion recovery following intermittent-sprint exercise in the heat.

Science.gov (United States)

Pointon, Monique; Duffield, Rob; Cannon, Jack; Marino, Frank E

2012-07-01

This study examined the effects of cold water immersion (CWI) on recovery of neuromuscular function following simulated team-sport exercise in the heat. Ten male team-sport athletes performed two sessions of a 2 × 30-min intermittent-sprint exercise (ISE) in 32°C and 52% humidity, followed by a 20-min CWI intervention or passive recovery (CONT) in a randomized, crossover design. The ISE involved a 15-m sprint every minute separated by bouts of hard running, jogging and walking. Voluntary and evoked neuromuscular function, ratings of perceived muscle soreness (MS) and blood markers for muscle damage were measured pre- and post-exercise, immediately post-recovery, 2-h and 24-h post-recovery. Measures of core temperature (Tcore), heart rate (HR), capillary blood and perceptions of exertion, thermal strain and thirst were also recorded at the aforementioned time points. Post-exercise maximal voluntary contraction (MVC) and activation (VA) were reduced in both conditions and remained below pre-exercise values for the 24-h recovery (P recovery period (P recovery rate of reduction in Tcore, HR and MS was enhanced with CWI whilst increasing MVC and VA (P recovery MVC and activation were significantly higher in CONT compared to CWI (P = 0.05). Following exercise in the heat, CWI accelerated the reduction in thermal and cardiovascular load, and improved MVC alongside increased central activation immediately and 2-h post-recovery. However, despite improved acute recovery CWI resulted in an attenuated MVC 24-h post-recovery.

Immersion studies on candidate container alloys for the Tuff Repository

International Nuclear Information System (INIS)

Beavers, J.A.; Durr, C.L.

1991-05-01

Cortest Columbus Technologies (CC Technologies) is investigating the long-term performance of container materials used for high-level radioactive waste packages. This information is being developed for the Nuclear Regulatory Commission to aid in their assessment of the Department of Energy's application to construct a geologic repository for disposal of high-level radioactive waste. This report summarizes the results of exposure studies performed on two copper-base and two Fe-Cr-Ni alloys in simulated Tuff Repository conditions. Testing was performed at 90 degrees C in three environments; simulated J-13 well water, and two environments that simulated the chemical effects resulting from boiling and irradiation of the groundwater. Creviced specimens and U-bends were exposed to liquid, to vapor above the condensed phase, and to alternate immersion. A rod specimen was used to monitor corrosion at the vapor-liquid interface. The specimens were evaluated by electrochemical, gravimetric, and metallographic techniques following approximately 2000 hours of exposure. Results of the exposure tests indicated that all four alloys exhibited acceptable general corrosion rates in simulated J-13 well water. These rates decreased with time. Incipient pitting was observed under deposits on Alloy 825 and pitting was observed on both Alloy CDA 102 and Alloy CDA 715 in the simulated J-13 well water. No SCC was observed in U-bend specimens of any of the alloys in simulated J-13 well water. 33 refs., 48 figs., 23 tabs

Sustaining dry surfaces under water

DEFF Research Database (Denmark)

Jones, Paul R.; Hao, Xiuqing; Cruz-Chu, Eduardo R.

2015-01-01

Rough surfaces immersed under water remain practically dry if the liquid-solid contact is on roughness peaks, while the roughness valleys are filled with gas. Mechanisms that prevent water from invading the valleys are well studied. However, to remain practically dry under water, additional...... mechanisms need consideration. This is because trapped gas (e.g. air) in the roughness valleys can dissolve into the water pool, leading to invasion. Additionally, water vapor can also occupy the roughness valleys of immersed surfaces. If water vapor condenses, that too leads to invasion. These effects have...... not been investigated, and are critically important to maintain surfaces dry under water.In this work, we identify the critical roughness scale, below which it is possible to sustain the vapor phase of water and/or trapped gases in roughness valleys – thus keeping the immersed surface dry. Theoretical...

Immersive Technologies and Language Learning

Science.gov (United States)

Blyth, Carl

2018-01-01

This article briefly traces the historical conceptualization of linguistic and cultural immersion through technological applications, from the early days of locally networked computers to the cutting-edge technologies known as virtual reality and augmented reality. Next, the article explores the challenges of immersive technologies for the field…

Sodium immersible high temperature microphone design description

International Nuclear Information System (INIS)

Gavin, A.P.; Anderson, T.T.; Janicek, J.J.

1975-02-01

Argonne National Laboratory has developed a rugged high-temperature (HT) microphone for use as a sodium-immersed acoustic monitor in Liquid Metal Fast Breeder Reactors (LMFBRs). Microphones of this design have been extensively tested in room temperature water, in air up to 1200 0 F, and in sodium up to 1200 0 F. They have been successfully installed and employed as acoustic monitors in several operating liquid metal systems. The design, construction sequence, calibration, and testing of these microphones are described. 6 references. (U.S.)

Learning immersion without getting wet

Science.gov (United States)

Aguilera, Julieta C.

2012-03-01

This paper describes the teaching of an immersive environments class on the Spring of 2011. The class had students from undergraduate as well as graduate art related majors. Their digital background and interests were also diverse. These variables were channeled as different approaches throughout the semester. Class components included fundamentals of stereoscopic computer graphics to explore spatial depth, 3D modeling and skeleton animation to in turn explore presence, exposure to formats like a stereo projection wall and dome environments to compare field of view across devices, and finally, interaction and tracking to explore issues of embodiment. All these components were supported by theoretical readings discussed in class. Guest artists presented their work in Virtual Reality, Dome Environments and other immersive formats. Museum professionals also introduced students to space science visualizations, which utilize immersive formats. Here I present the assignments and their outcome, together with insights as to how the creation of immersive environments can be learned through constraints that expose students to situations of embodied cognition.

Forcing clique immersions through chromatic number

OpenAIRE

Gauthier, Gregory; Le, Tien-Nam; Wollan, Paul

2017-01-01

Building on recent work of Dvo\\v{r}\\'ak and Yepremyan, we show that every simple graph of minimum degree $7t+7$ contains $K_t$ as an immersion and that every graph with chromatic number at least $3.54t + 4$ contains $K_t$ as an immersion. We also show that every graph on $n$ vertices with no stable set of size three contains $K_{2\\lfloor n/5 \\rfloor}$ as an immersion.

Designing immersion exhibits as border-crossing environments

DEFF Research Database (Denmark)

Mortensen, Marianne Foss

2010-01-01

be applied to achieve an understanding of the immersion exhibit form. The argument proceeds by demonstrating how the characteristics of immersion exhibits, and visitors to them, classify them as microcultures, and examining the implications of this for exhibit design using a hypothetical immersion exhibit...

Water Exchange Produces Significantly Higher Adenoma Detection Rate Than Water Immersion: Pooled Data From 2 Multisite Randomized Controlled Trials.

Science.gov (United States)

Leung, Felix W; Koo, Malcolm; Cadoni, Sergio; Falt, Premysl; Hsieh, Yu-Hsi; Amato, Arnaldo; Erriu, Matteo; Fojtik, Petr; Gallittu, Paolo; Hu, Chi-Tan; Leung, Joseph W; Liggi, Mauro; Paggi, Silvia; Radaelli, Franco; Rondonotti, Emanuele; Smajstrla, Vit; Tseng, Chih-Wei; Urban, Ondrej

2018-03-02

To test the hypothesis that water exchange (WE) significantly increases adenoma detection rates (ADR) compared with water immersion (WI). Low ADR was linked to increased risk for interval colorectal cancers and related deaths. Two recent randomized controlled trials of head-to-head comparison of WE, WI, and traditional air insufflation (AI) each showed that WE achieved significantly higher ADR than AI, but not WI. The data were pooled from these 2 studies to test the above hypothesis. Two trials (5 sites, 14 colonoscopists) that randomized 1875 patients 1:1:1 to AI, WI, or WE were pooled and analyzed with ADR as the primary outcome. The ADR of AI (39.5%) and WI (42.4%) were comparable, significantly lower than that of WE (49.6%) (vs. AI P=0.001; vs. WI P=0.033). WE insertion time was 3 minutes longer than that of AI (Prate (vs. AI) of the >10 mm advanced adenomas. Right colon combined advanced and sessile serrated ADR of AI (3.4%) and WI (5%) were comparable and were significantly lower than that of WE (8.5%) (vs. AI P<0.001; vs. WI P=0.039). Compared with AI and WI, the superior ADR of WE offsets the drawback of a significantly longer insertion time. For quality improvement focused on increasing adenoma detection, WE is preferred over WI. The hypothesis that WE could lower the risk of interval colorectal cancers and related deaths should be tested.

Teaching corner: raising the bar: ethical considerations of medical student preparation for short-term immersion experiences.

Science.gov (United States)

Kittle, Nathan; McCarthy, Virginia

2015-03-01

Short-term international medical outreach experiences are becoming more popular among medical students. As the popularity of these trips grows, participants, scholars, and institutions have become more aware of the potential pitfalls of such experiences. Loyola University Chicago Stritch School of Medicine (SSOM) has an approximately 20-year international service immersion (ISI) program that has sent more than 1,400 participants to more than 30 countries. Recently, ISI programming has been adjusted to provide students more formal sessions exploring the ethics of the ISI trips. Students are required to attend both pre- and post-trip educational sessions covering a wide range of relevant global health topics as well as participating in in-country reflections and post-trip debriefings. This recent adjustment has evolved further to become the foundation for the SSOM's four-year Global Health Honors program that not only encourages an ethical foundation for the student's ISI experience but also hopes to provide a foundation for students as they look toward a future career in global health.

The efficacy of alfaxalone for immersion anesthesia in koi carp (Cyprinus carpio).

Science.gov (United States)

Minter, Larry J; Bailey, Kate M; Harms, Craig A; Lewbart, Gregory A; Posner, Lysa P

2014-07-01

To characterize the physiologic and behavioral effects of a single induction dose and two maintenance doses of alfaxalone delivered by water immersion in the anesthesia of koi (Cyprinus carpio). Prospective, within-subject complete crossover design. Six adult koi (Cyprinus carpio) with a median body weight of 344.5 g (range 292.0-405.0 g). Koi were immersed in water containing 10 mg L(-1) alfaxalone until immobile and then maintained with alfaxalone at either 1 or 2.5 mg L(-1) via a recirculating water system. Times for anesthetic induction and recovery periods were recorded. Physiologic and blood gas parameters were evaluated before, during and after the anesthetic trial. Response to noxious stimuli was also assessed. Median anesthesia induction time for all fish was 5.4 minutes. Median recovery time was 11.8 and 26.4 minutes in the 1.0 and 2.5 mg L(-1) doses, respectively, which were significantly different (p = 0.04). Cessation of opercular movement occurred in 0/6 and 4/6 fish exposed to 1.0 and 2.5 mg L(-1) dose respectively. No difference was observed in median heart rate over the duration of the anesthetic events. Response to noxious stimulation was 4/6 and 0/6 in the 1.0 and 2.5 mg L(-1) doses respectively. Oxygenation and ventilation did not change during the experiment, but there was a significant decrease in blood pH along with an increase in blood lactate concentration. Administration of alfaxalone, via water immersion, as an induction and maintenance anesthesia agent provided rapid and reliable anesthesia of koi with no mortality. The maintenance dose of 2.5 mg L(-1) was sufficient to prevent response to noxious stimuli but was associated with a clinically relevant depression in opercular rate. © 2014 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia.

[The antigravity suit, chamberless type, as a means of increasing orthostatic tolerance after water immersion hypokinesis and acceleration].

Science.gov (United States)

Shul'zhenko, E B; Kozlova, V G; Kurdin, K A; Iarov, A S; Plokhova, V G

1983-01-01

Orthostatic tolerance after 7-day dry immersion and head-to-feet acceleration was investigated on test subjects with and without an antigravity suit of bladderless type. With the suit on, the 20 min tilt test at 70 degrees prior to immersion induced less marked changes than without the suit. When the suit was on, cardiovascular reactions to tilt tests after immersion and acceleration improved. The maximum heart rate decreased from 135 +/- 4 to 101 +/- 5 beats/min (p less than 0.01), minimum stroke volume increased from 29 +/- 2 to 41 +/- 3 ml (p less than 0.05), and pulse pressure grew. Thus, an antigravity suit may help increase initial orthostatic tolerance and maintain it after the combined effect of simulated hypogravity and acceleration.

Preparation of ultrafine grained copper nanoparticles via immersion deposit method

Science.gov (United States)

Abbasi-Kesbi, Fatemeh; Rashidi, Ali Mohammad; Astinchap, Bandar

2018-03-01

Today, the exploration about synthesis of nanoparticles is much of interest to materials scientists. In this work, copper nanoparticles have been successfully synthesized by immersion deposit method in the absence of any stabilizing and reducing agents. Copper (II) sulfate pentahydrate as precursor salt and distilled water and Ethylene glycol as solvents were used. The copper nanoparticles were deposited on plates of low carbon steel. The effects of copper sulfate concentrations and solvent type were investigated. X-ray diffraction, scanning electron microscopy and UV-Visible spectroscopy were taken to investigate the crystallite size, crystal structure, and morphology and size distribution and the growth process of the nanoparticles of obtained Cu particles. The results indicated that the immersion deposit method is a particularly suitable method for synthesis of semispherical copper nanoparticles with the crystallites size in the range of 22 to 37 nm. By increasing the molar concentration of copper sulfate in distilled water solvent from 0.04 to 0.2 M, the average particles size is increased from 57 to 81 nm. The better size distribution of Cu nanoparticles was achieved using a lower concentration of copper sulfate. By increasing the molar concentration of copper sulfate in water solvent from 0.04 to 0.2, the location of the SPR peak has shifted from 600 to 630 nm. The finer Cu nanoparticles were formed using ethylene glycol instead water as a solvent. Also, the agglomeration and overlapping of nanoparticles in ethylene glycol were less than that of water solvent.

Reshaping Spectatorship: Immersive and Distributed Aesthetics

Directory of Open Access Journals (Sweden)

Edwina Bartlem

2005-01-01

Full Text Available Although discourses of immersive aesthetics and distributed aesthetics may evoke associations with different media, creative processes, modes of audience engagement and even political ideologies, artists using these aesthetics often share similar interests in transforming and enhancing notions of the body and perception through technological intervention. This paper undertakes a comparison between immersive and distributed aesthetics in relation to Virtual Reality (VR and Networked Art (net.art, particularly networked installation art. It focuses on the ways in which both VR and networked installations immerse the viewer in states of perceptual and cognitive transition. Central to this article is the argument that VR and net.art are able to generate immersive experiences in the viewer by creating the sensation of being (tele-present in an electronically mediated environment that is illusionistic and sometimes remote from the physical body of the participant. Furthermore, the immersive and distributed aesthetics generated by specific VR and net.art projects have revolutionary consequences for traditional aesthetic theories of spectatorship and art appreciation that assert the need for critical and physical distance.

Water depth effects on impact loading, kinematic and physiological variables during water treadmill running.

Science.gov (United States)

Macdermid, Paul W; Wharton, Josh; Schill, Carina; Fink, Philip W

2017-07-01

The purpose of this study was to compare impact loading, kinematic and physiological responses to three different immersion depths (mid-shin, mid-thigh, and xiphoid process) while running at the same speed on a water based treadmill. Participants (N=8) ran on a water treadmill at three depths for 3min. Tri-axial accelerometers were used to identify running dynamics plus measures associated with impact loading rates, while heart rate data were logged to indicate physiological demand. Participants had greater peak impact accelerations (prunning immersed to the xiphoid process. Physiological effort determined by heart rate was also significantly less (prunning immersed to the xiphoid process. Water immersed treadmill running above the waistline alters kinematics of gait, reduces variables associated with impact, while decreasing physiological demand compared to depths below the waistline. Copyright © 2017 Elsevier B.V. All rights reserved.

The Impact of Early French Immersion Education on Language Use Patterns and Language Attitude of Post-Secondary Students

Science.gov (United States)

Nix-Victorian, Janice M.

2010-01-01

Even though there are increasing numbers of Early Partial Immersion (EPI) programs in Louisiana, there was no data available on the long-term impact of these programs. The purpose of this study is to delve into the experiences of 10 former immersion students in order to reveal their accounts and perceptions of their bilingual abilities, their…

Porous Media and Immersed Boundary Hybrid-Modelling for Simulating Flow in Stone Cover-Layers

DEFF Research Database (Denmark)

Jensen, Bjarne; Liu, Xiaofeng; Christensen, Erik Damgaard

In this paper we present a new numerical modelling approach for coastal and marine applications where a porous media conceptual model was combined with a free surface volume-of-fluid (VOF) model and an immersed boundary method (IBM). The immersed boundary model covers the method of describing....... In this paper, the model is applied to investigate two practical cases in terms of a cover layer of stones on a flat bed under oscillatory flow at different packing densities, and a rock toe structure at a breakwater....

Water storage capacity, stemflow and water funneling in Mediterranean shrubs

Science.gov (United States)

Garcia-Estringana, P.; Alonso-Blázquez, N.; Alegre, J.

2010-08-01

SummaryTo predict water losses and other hydrological and ecological features of a given vegetation, its water storage capacity and stemflow need to be accurately determined. Vast areas of the Mediterranean region are occupied by shrublands yet there is scarce data available on their rainwater interception capacity. In this study, simulated rainfall tests were conducted in controlled conditions on nine Mediterranean shrubs of varying anatomic and morphological features to determine water storage capacity, stemflow and the funneling ratio. After assessing correlations between these hydrological variables and the biometric characteristics of the shrubs, we compared two methods of determining storage capacity: rainfall simulation and immersion. Mean water storage capacity was 1.02 mm (0.35-3.24 mm), stemflow was 16% (3.8-26.4%) and the funneling ratio was 104 (30-260). Per unit biomass, mean storage capacity was 0.66 ml g -1 and ranged from 0.23 ml g -1 for Cistus ladanifer to 2.26 ml g -1 for Lavandula latifolia. Despite their small size, shrubs may generate high water losses to the atmosphere when they form dense communities and this can have a significant impact in regions where water is scarce. When considered the whole shrubs in absolute terms (ml per plant), water storage capacity and stemflow were correlated to biomass and the dendrometric characteristics of the shrubs, yet in relative terms (expressed per surface area unit or as %), anatomic features such as pubescence, branch rigidity or leaf insertion angle emerged as determining factors. The use of a simple procedure to assess storage capacity was inefficient. The immersion method underestimated storage capacity to a different extent for each species. Some shrubs returned high stemflow values typical of their adaptation to the semiarid climate. In contrast, other shrubs seem to have structures that promote stemflow yet have developed other drought-adaptation mechanisms. In this report, we discuss the

Changes in mechanical properties and morphology of elastomer coatings after immersion in salt solutions

Science.gov (United States)

Terán Arce, Fernando; Avci, Recep; Beech, Iwona; Cooksey, Keith; Wigglesworth-Cooksey, Barbara

2004-03-01

RTV11 (^TM GE Silicones) and Intersleek (^TM International Paints) are two elastomers of considerable significance to the navy and maritime industry for their application as fouling release coatings. Both materials are composed of polymeric matrices with embedded filler particles, which provide increased strength and durability to the elastomer. Using Atomic force microscopy (AFM), surface and bulk analysis techniques, we have found surface regions with microelastic properties, which correlate with the locations of filler particles inside the coatings. These particles are able to undergo elastic displacements of hundreds of nm inside the polymeric matrix during compression by the AFM tip. While elastic properties of Intersleek remain largely unchanged after immersion in salt solutions, roughening, embrittlement and stiffening occurs in RTV11 coatings depending on the amount of curing agent and humidity used during preparation and curing, respectively. Interestingly, such transformations are absent after immersion in pure water. In particle free regions, elastic moduli of RTV11 take values of 2 - 3 MPa before immersion in salt solutions. After immersion, those values increase 5 - 10 times.

FIJI: A Framework for the Immersion-Journalism Intersection

OpenAIRE

Hardee, Gary M.; McMahan, Ryan P.

2017-01-01

As journalists experiment with developing immersive journalism—first-person, interactive experiences of news events—guidelines are needed to help bridge a disconnect between the requirements of journalism and the capabilities of emerging technologies. Many journalists need to better understand the fundamental concepts of immersion and the capabilities and limitations of common immersive technologies. Similarly, developers of immersive journalism works need to know the fundamentals that define...

Human thermal responses during leg-only exercise in cold water.

Science.gov (United States)

Golden, F S; Tipton, M J

1987-10-01

1. Exercise during immersion in cold water has been reported by several authors to accelerate the rate of fall of core temperature when compared with rates seen during static immersion. The nature of the exercise performed, however, has always been whole-body in nature. 2. In the present investigation fifteen subjects performed leg exercise throughout a 40 min head-out immersion in water at 15 degrees C. The responses obtained were compared with those seen when the subjects performed an identical static immersion. 3. Aural and rectal temperatures were found to fall by greater amounts during static immersion. 4. It is concluded that 'the type of exercise performed' should be included in the list of factors which affect core temperature during cold water immersion.

Immersed boundary method combined with a high order compact scheme on half-staggered meshes

International Nuclear Information System (INIS)

Księżyk, M; Tyliszczak, A

2014-01-01

This paper presents the results of computations of incompressible flows performed with a high-order compact scheme and the immersed boundary method. The solution algorithm is based on the projection method implemented using the half-staggered grid arrangement in which the velocity components are stored in the same locations while the pressure nodes are shifted half a cell size. The time discretization is performed using the predictor-corrector method in which the forcing terms used in the immersed boundary method acts in both steps. The solution algorithm is verified based on 2D flow problems (flow in a lid-driven skewed cavity, flow over a backward facing step) and turns out to be very accurate on computational meshes comparable with ones used in the classical approaches, i.e. not based on the immersed boundary method.

Teaching Visual Arts - From the Innocent Eye to Immersiveness and Vice Versa

Directory of Open Access Journals (Sweden)

Marijan Richter

2017-09-01

Full Text Available In the mid-19th century, John Ruskin, apologist for the poetics of the innocent eye, advocated a break with academic Realism. A century later, Gombrich and Goodman criticized Ruskin's Romantic subjectivism from the position of High Modernism. Consequently, the "Enlightenment" approach in teaching visual arts became stronger. Recently, some teaching specialists have been trying to inaugurate the term, immersiveness, in place of visual arts language for the purpose of introducing contemporary art into the syllabus. This paper examines the relation between "the innocent eye myth" and topical approach of "immersiveness" within the framework of educational objectives and methods in contemporary teaching.

Immersion and Gameplay Experience: A Contingency Framework

Directory of Open Access Journals (Sweden)

Daniel Örtqvist

2010-01-01

Full Text Available The nature of the relationship between immersion and gameplay experience is investigated, focusing primarily on the literature related to flow. In particular, this paper proposes that immersion and gameplay experience are conceptually different, but empirically positively related through mechanisms related to flow. Furthermore, this study examines gamers' characteristics to determine the influence between immersion and gameplay experiences. The study involves 48 observations in one game setting. Regression analyses including tests for moderation and simple slope analysis are used to reveal gamers' age, experience, and understanding of the game, which moderate the relationship between immersion and gameplay experience. The results suggest that immersion is more positive for gameplay experience when the gamer lacks experience and understanding of the game as well as when the gamer is relatively older. Implications and recommendations for future research are discussed at length in the paper.

Impacts of cloud immersion on microclimate, photosynthesis and water relations of fraser fir in a temperate mountain cloud forest

Science.gov (United States)

Keith Reinhardt; William K. Smith

2010-01-01

The red spruce-Fraser fir ecosystem (Picea rubens Sarg.-Abies fraseri [Pursh] Poir.) of the southern Appalachian mountains is a temperate zone cloud forest immersed in clouds for 30 to 40 percent of a typical summer day, and experiencing immersion on about 65 percent of all days annually. We compared the microclimate,...

Environmental test program for superconducting materials and devices. Mid-Term Report, May 1990 - Jun. 1991

International Nuclear Information System (INIS)

Haertling, G.; Randolph, H.; Hsi, Chi-Shiung; Verbelyi, D.

1991-07-01

This report is divided into two parts. The first dealing with work involved with Clemson University and the second with the results from Westinghouse/Savannah River. Both areas of work involved low noise, low thermal conductivity superconducting grounding links used in the NASA-sponsored Spectroscopy of the Atmosphere using Far Infrared Emission (SAFIRE) Project. Clemson prepared the links from YBa2Cu3O(7-x) superconductor tape that was mounted on a printed circuit board and encapsulated with epoxy resin. The Clemson program includes temperature vs. resistance, liquid nitrogen immersion, water immersion, thermal cycling, humidity, and radiation testing. The evaluation of the links under a long term environmental test program is described. The Savannah River program includes gamma irradiation, vibration, and long-term evaluation. The progress made in these evaluations is discussed

Color stability assessment of two different composite resins with variable immersion time using various beverages: An In vitro study

Directory of Open Access Journals (Sweden)

M Senthil Kumar

2017-01-01

Full Text Available Purpose of the Study: The aim of the study was to evaluate the difference in the color of microhybrid (MH and nanofilled (NF composite resins after 24 and 48 h in beverages such as red wine (RW, Coca-Cola, and distilled water. The specific objective of this study was to investigate the cumulative effect of the colorant solutions on the dental composites. Materials and Methods: MH and NF composite resins (A2 shade were used in this current study. Sixty disk-shaped material specimens (10 mm in diameter × 2 mm in thickness were prepared using a fiber mold (ring, with the desired dimensions. The specimen surfaces were polished using super-snap polishing system. Sixty specimens were divided into two groups of 30 each (Group I: MH resin composite; Group II: NF resin composite. Both the groups divided into six subgroups (Subgroup I: RW for 24 h [RW-24]; Subgroup II: RW for 48 h; Subgroup III: Coca-Cola for 24 h [CC-24]; Subgroup IV: Coca-Cola for 48 h [CC-48]; Subgroup V: Distilled water for 24 h [DW-24]; Subgroup VI: Distilled water for 48 h [DW-48]. All the samples were immersed in respective drinks for a period of 24 h, and color differences were measured using ultraviolet spectrophotometer. Once again, all the samples were immersed for another 24 h in the same drinks. After 48 h, the color change of the samples was measured. Measurements were made according to the CIE L × a × b × color space relative to the CIE standard illuminant D65. The color changes of the specimens were evaluated using the following formula: [INSIDE:1]Statistical analysis was performed. The data were analyzed using the one-way ANOVA and t-test at a significance level of 0.05. Conclusion: Color stability of MH composite resin was found to be inferior than the NF resin composite irrespective of immersion medium and time. In RW, the color change observed was maximum for both composite resins followed by Coca-Cola. Immersing the resin composites in distilled water for 24 and

L'expression orale apres treize ans d'immersion francaise (Oral Expression After Thirteen Years of French Immersion).

Science.gov (United States)

Pellerin, Micheline; Hammerly, Hector

1986-01-01

Conversations with six twelfth graders who had been in French immersion since kindergarten found a high rate of incorrect sentences, suggesting a faulty interlanguage fossilized at grade six and a need for immersion program revision. (MSE)

Development of the immersed sodium flowmeter

International Nuclear Information System (INIS)

Chen Daolong

1994-09-01

An immersed sodium flowmeter of the range 3 m 3 /h is developed. It is a flowmeter of entire-sealed construction, it can be operated in sodium. Its construction, the theoretical calculation of the calibration characteristic and the pressure loss, the test facility and the calibration test are presented in detail. It analytical expression of the calibration characteristic in the temperature limit 200∼600 degree C and the error analysis are given. The basic error of this immersed sodium flowmeter is below +-2.3% of the measuring range. The immersed sodium flowmeter can be used to resolve the sodium flowrate measuring problems of the in-reactor component of LMFBR, for example, the flowrate measuring of the in-reactor sodium purification loop, the flowrate measuring of the immersed sodium pump and the flowrate measuring of the in-reactor test component

Shivering heat production and core cooling during head-in and head-out immersion in 17 degrees C water.

Science.gov (United States)

Pretorius, Thea; Cahill, Farrell; Kocay, Sheila; Giesbrecht, Gordon G

2008-05-01

Many cold-water scenarios cause the head to be partially or fully immersed (e.g., ship wreck survival, scuba diving, cold-water adventure swim racing, cold-water drowning, etc.). However, the specific effects of head cold exposure are minimally understood. This study isolated the effect of whole-head submersion in cold water on surface heat loss and body core cooling when the protective shivering mechanism was intact. Eight healthy men were studied in 17 degrees C water under four conditions: the body was either insulated or exposed, with the head either out of the water or completely submersed under the water within each insulated/exposed subcondition. Submersion of the head (7% of the body surface area) in the body-exposed condition increased total heat loss by 11% (P < 0.05). After 45 min, head-submersion increased core cooling by 343% in the body-insulated subcondition (head-out: 0.13 +/- 0.2 degree C, head-in: 0.47 +/- 0.3 degree C; P < 0.05) and by 56% in the body-exposed subcondition (head-out: 0.40 +/- 0.3 degree C and head-in: 0.73 +/- 0.6 degree C; P < 0.05). In both body-exposed and body-insulated subconditions, head submersion increased the rate of core cooling disproportionally more than the relative increase in total heat loss. This exaggerated core-cooling effect is consistent with a head cooling induced reduction of the thermal core, which could be stimulated by cooling of thermosensitive and/or trigeminal receptors in the scalp, neck, and face. These cooling effects of head submersion are not prevented by shivering heat production.

The pedagogical practices of a teacher of Portuguese Foreign Language (PLE in immersion and non-immersion context

Directory of Open Access Journals (Sweden)

Nildicéia Aparecida Rocha

2016-05-01

Full Text Available The aim of this paper is to present a reflection on the specifics of teaching Portuguese as a Foreign Language (PLE both in the context of immersion and outside it, from the observations carried out in two stages: first, the practice of a teacher PLE will be described in immersion situation at a university in the state of São Paulo, Brazil; and then practice the same teacher in a course of PLE out of the immersion context, at a university in Spain, in a provincial capital. In this sense, the teaching practice will be analyzed from a teacher of PLE in immersion situation and beyond when the didactic and pedagogical treatment of the inseparable relationship between language and culture within an intercultural communicative approach. It is a qualitative research in which it is a case of state, showing the practice of one teacher (research subjects in two socio-historically different contexts, but with the same approach. The survey results indicate that the teacher's practice in non-immersion context had to be re-signified to enable PLE learning in such a context. In fact, the teacher had to redefine their practice and deconstruct a belief and turn to the theory, according to their didactic and pedagogical and linguistic concerns, finding that the examination of social, historical and cultural data should always be the guiding and / or determinants as regards the teaching of a foreign language, in particular PLE out of immersion.

Curcumin, a polyphenolic antioxidant, attenuates chronic fatigue syndrome in murine water immersion stress model.

Science.gov (United States)

Gupta, Amit; Vij, Garima; Sharma, Sameer; Tirkey, Naveen; Rishi, Praveen; Chopra, Kanwaljit

2009-01-01

Chronic fatigue syndrome, infection and oxidative stress are interrelated in epidemiological case studies. However, data demonstrating scientific validation of epidemiological claims regarding effectiveness of nutritional supplements for chronic fatigue syndrome are lacking. This study is designed to evaluate the effect of natural polyphenol, curcumin, in a mouse model of immunologically induced fatigue, where purified lipopolysaccharide (LPS) and Brucella abortus (BA) antigens were used as immunogens. The assessment of chronic fatigue syndrome was based on chronic water-immersion stress test for 10 min daily for 19 days and the immobility time was taken as the marker of fatigue. Mice challenged with LPS or BA for 19 days showed significant increase in the immobility time and hyperalgesia on day 19, as well as marked increase in serum tumor necrosis factor-alpha (TNF-alpha) levels. Concurrent treatment with curcumin resulted in significantly decreased immobility time as well as hyperalgesia. There was significant attenuation of oxidative stress as well as TNF-alpha levels. These findings strongly suggest that during immunological activation, there is significant increase in oxidative stress and curcumin can be a valuable option in the treatment of chronic fatigue syndrome.

Estimation of immersion dose to the Tin mining in the seashore of Bangka island from NPP operation

International Nuclear Information System (INIS)

Nurokhim; Erwansyah Lubis

2015-01-01

The estimation of immersion dose to the Tin (Sn) mining in the seashore of Bangka island using concentrations factor methods was carried out. In the estimation, the source-term of effluent released to Pacific ocean from Diablo Canyon and San Onofre Nuclear Power Plant (NPP) operations was used. The results indicated that the Sn mining with immersion in the sea water of 2, 4 and 6 hours per day will receives maximum effective dose of 4.45 × 10 -3 %; 8.90 ×10 -3 % and 1.34 × 10 -2 % from dose constraint of 0.3 mSv per years. The probability of cancer happen for individual are 2.67 × 10 -8 ; 5.34 × 10 -8 and 8.01 × 10 -8 respectively if the working hours are 2, 4 dan 6 hours per days as long as 40 years (reactor lifetime) . These data give the information if there are 50 millions of Sn mining, the potential of miner will receive a fatal cancer is around 4 persons. According to the population of Sn mining is very small, so the probabilities of fatal cancer is unsignificant. (author)

A review of characteristics and outcomes of Australia's undergraduate medical education rural immersion programs.

Science.gov (United States)

O'Sullivan, Belinda G; McGrail, Matthew R; Russell, Deborah; Chambers, Helen; Major, Laura

2018-01-31

in rural practice and the duration and setting of immersion on rural work uptake and working more remotely. Research needs to be more nationally balanced and scaled-up to inform national policy development. Critically, the quality of research could be strengthened through longer-term follow-up studies, adjusting for known confounders, accounting for postgraduate stages and using appropriate controls to test the relative effects of student characteristics and program designs.

Consecutive days of cold water immersion: effects on cycling performance and heart rate variability.

Science.gov (United States)

Stanley, Jamie; Peake, Jonathan M; Buchheit, Martin

2013-02-01

We investigated performance and heart rate (HR) variability (HRV) over consecutive days of cycling with post-exercise cold water immersion (CWI) or passive recovery (PAS). In a crossover design, 11 cyclists completed two separate 3-day training blocks (120 min cycling per day, 66 maximal sprints, 9 min time trialling [TT]), followed by 2 days of recovery-based training. The cyclists recovered from each training session by standing in cold water (10 °C) or at room temperature (27 °C) for 5 min. Mean power for sprints, total TT work and HR were assessed during each session. Resting vagal-HRV (natural logarithm of square-root of mean squared differences of successive R-R intervals; ln rMSSD) was assessed after exercise, after the recovery intervention, during sleep and upon waking. CWI allowed better maintenance of mean sprint power (between-trial difference [90 % confidence limits] +12.4 % [5.9; 18.9]), cadence (+2.0 % [0.6; 3.5]), and mean HR during exercise (+1.6 % [0.0; 3.2]) compared with PAS. ln rMSSD immediately following CWI was higher (+144 % [92; 211]) compared with PAS. There was no difference between the trials in TT performance (-0.2 % [-3.5; 3.0]) or waking ln rMSSD (-1.2 % [-5.9; 3.4]). CWI helps to maintain sprint performance during consecutive days of training, whereas its effects on vagal-HRV vary over time and depend on prior exercise intensity.

Heat transfer characteristics around a single heated rod immersed in sodium pool with gas jet injection

International Nuclear Information System (INIS)

Hideto Niikura; Kazuo Soga; Ken-ichiro Sugiyama; Akira Yamaguchi

2005-01-01

In a steam generator using liquid sodium, water intensely reacts with sodium when it leaks out from a heat transfer tube. It is important to evaluate the influence of sodium-water reaction to surrounding tubes and the shell. Hence, it has been desired to develop the simulation code for the evaluation of sodium-water reaction. From this viewpoint, the Japan Nuclear Cycle is now developing the SERAPHIM code. We reported a preliminary study to establish an experimental method for a single heated rod immersed in sodium pool with steam jet impingement planned in the near future as well as to obtain a preliminary data to verify the adequacy of SERAPHIM code. We first measured local and mean heat transfer coefficients around a horizontal single heated rod immersed in a water pool and a sodium pool with a limited volume in the experimental apparatus. It was confirmed that the mean heat transfer coefficients fairly agreed with the existing data for natural convection in water and sodium. Secondary we measured local and mean heat transfer coefficients around a horizontal single heated rod with Ar gas jet impingement immersed in the limited water pool and in the limited sodium pool. It was clearly observed that the local heat transfer coefficients in the sodium pool keep almost the same values in every angle regardless of increase in Ar gas jet velocity varied from about 8.7m/s to about 78m/s. On the other hand, it was confirmed in the water pool that local heat transfer coefficients on the forward stagnation side exposed in the Ar gas jet impingement increase with increasing the jet velocity while the local heat transfer coefficients on the opposite surface keep almost same values regardless of increase in the velocity. (authors)

Finite-volume discretizations and immersed boundaries

NARCIS (Netherlands)

Y.J. Hassen (Yunus); B. Koren (Barry)

2009-01-01

htmlabstractIn this chapter, an accurate method, using a novel immersed-boundary approach, is presented for numerically solving linear, scalar convection problems. As is standard in immersed-boundary methods, moving bodies are embedded in a fixed `Cartesian' grid. The essence of the present method

Finite-volume discretizations and immersed boundaries

NARCIS (Netherlands)

Y.J. Hassen (Yunus); B. Koren (Barry)

2010-01-01

textabstractIn this chapter, an accurate method, using a novel immersed-boundary approach, is presented for numerically solving linear, scalar convection problems. As is standard in immersed-boundary methods, moving bodies are embedded in a fixed Cartesian grid. The essence of the present method is

Heat transfer comparison of nanofluid filled transformer and traditional oil-immersed transformer

Science.gov (United States)

Zhang, Yunpeng; Ho, Siu-lau; Fu, Weinong

2018-05-01

Dispersing nanoparticles with high thermal conductivity into transformer oil is an innovative approach to improve the thermal performance of traditional oil-immersed transformers. This mixture, also known as nanofluid, has shown the potential in practical application through experimental measurements. This paper presents the comparisons of nanofluid filled transformer and traditional oil-immersed transformer in terms of their computational fluid dynamics (CFD) solutions from the perspective of optimal design. Thermal performance of transformers with the same parameters except coolants is compared. A further comparison on heat transfer then is made after minimizing the oil volume and maximum temperature-rise of these two transformers. Adaptive multi-objective optimization method is employed to tackle this optimization problem.

Immersion Ethnography of Elites

DEFF Research Database (Denmark)

Harrington, Brooke

2016-01-01

This chapter examines an innovative form of data-gathering that brings together two of the greatest methodological challenges social scientists face: conducting classical immersion ethnography and gaining access to elites. The difficulties of accessing elites for research purposes have been well......-documented (Conti and O’Neill 2007; Gilding 2010; Harrington 2003). There has been less scholarly discussion of the challenges posed by traditional ethnography, a method whose claim to scientific status is based on the length and depth of the investigator’s immersion in an organization or culture....

Corrosion control by limestone immersion into the hot water heat-storage tank. Case history of air-conditioning systems of Sapporo city subway stations; Sekkaiseki shinsekiho ni yoru chikunetsu onsui keito no boshoku koka. Sapporoshi chikatetsu kakueki no kucho setsubi no jirei

Energy Technology Data Exchange (ETDEWEB)

Kishi, M. [Sapporo City Transportation Bureau, Sapporo (Japan); Okumura, J. [Hokkaido Nikken Sekkei Ltd., Sapporo (Japan); Sakai, Y.; Shiiya, O. [Takasago Thermal Engineering Co. Ltd., Tokyo (Japan)

1995-06-05

Limestone immersion into heat-storage water tanks is a method for improving the water quality so as to encrust inner surface of piping by corrosion-preventive calcium carbonate film. For air-conditioning of Support city subway stations, heat-storing heat-pump systems with heat recovery from exhaust air have been introduced and developed for energy saving along with expansion of the subway routes. Inner surfaces of the heat-storage water tanks of all stations are coated with FRP-lining, therefore, some corrosion-preventive chemicals had been dosed from the starting up. However, the storage waters of all stations turned to red because of continuity of the piping corrosion. Instead of dosing chemicals, the limestone immersion method station. Thanks to His method, excellent results were obtained in a short period contributing control of the piping corrosion together with the red water fading. 14 figs., 1 tab.

KinImmerse: Macromolecular VR for NMR ensembles

Directory of Open Access Journals (Sweden)

Vinson E Claire

2009-02-01

Full Text Available Abstract Background In molecular applications, virtual reality (VR and immersive virtual environments have generally been used and valued for the visual and interactive experience – to enhance intuition and communicate excitement – rather than as part of the actual research process. In contrast, this work develops a software infrastructure for research use and illustrates such use on a specific case. Methods The Syzygy open-source toolkit for VR software was used to write the KinImmerse program, which translates the molecular capabilities of the kinemage graphics format into software for display and manipulation in the DiVE (Duke immersive Virtual Environment or other VR system. KinImmerse is supported by the flexible display construction and editing features in the KiNG kinemage viewer and it implements new forms of user interaction in the DiVE. Results In addition to molecular visualizations and navigation, KinImmerse provides a set of research tools for manipulation, identification, co-centering of multiple models, free-form 3D annotation, and output of results. The molecular research test case analyzes the local neighborhood around an individual atom within an ensemble of nuclear magnetic resonance (NMR models, enabling immersive visual comparison of the local conformation with the local NMR experimental data, including target curves for residual dipolar couplings (RDCs. Conclusion The promise of KinImmerse for production-level molecular research in the DiVE is shown by the locally co-centered RDC visualization developed there, which gave new insights now being pursued in wider data analysis.

What are the Physiological Mechanisms for Post-Exercise Cold Water Immersion in the Recovery from Prolonged Endurance and Intermittent Exercise?

Science.gov (United States)

Ihsan, Mohammed; Watson, Greig; Abbiss, Chris R

2016-08-01

Intense training results in numerous physiological perturbations such as muscle damage, hyperthermia, dehydration and glycogen depletion. Insufficient/untimely restoration of these physiological alterations might result in sub-optimal performance during subsequent training sessions, while chronic imbalance between training stress and recovery might lead to overreaching or overtraining syndrome. The use of post-exercise cold water immersion (CWI) is gaining considerable popularity among athletes to minimize fatigue and accelerate post-exercise recovery. CWI, through its primary ability to decrease tissue temperature and blood flow, is purported to facilitate recovery by ameliorating hyperthermia and subsequent alterations to the central nervous system (CNS), reducing cardiovascular strain, removing accumulated muscle metabolic by-products, attenuating exercise-induced muscle damage (EIMD) and improving autonomic nervous system function. The current review aims to provide a comprehensive and detailed examination of the mechanisms underpinning acute and longer term recovery of exercise performance following post-exercise CWI. Understanding the mechanisms will aid practitioners in the application and optimisation of CWI strategies to suit specific recovery needs and consequently improve athletic performance. Much of the literature indicates that the dominant mechanism by which CWI facilitates short term recovery is via ameliorating hyperthermia and consequently CNS mediated fatigue and by reducing cardiovascular strain. In contrast, there is limited evidence to support that CWI might improve acute recovery by facilitating the removal of muscle metabolites. CWI has been shown to augment parasympathetic reactivation following exercise. While CWI-mediated parasympathetic reactivation seems detrimental to high-intensity exercise performance when performed shortly after, it has been shown to be associated with improved longer term physiological recovery and day to day

Immersion Strategies.

Science.gov (United States)

Lorenz, Eileen B.

Four classroom activities useful for language immersion instruction are described and specific applications and extensions are noted. All are best used to teach content and language at the same time. The first, entitled "Think-Pair-Share," is a cooperative learning technique that increases student participation in classroom experiences and…

iVFTs - immersive virtual field trips for interactive learning about Earth's environment.

Science.gov (United States)

Bruce, G.; Anbar, A. D.; Semken, S. C.; Summons, R. E.; Oliver, C.; Buxner, S.

2014-12-01

Innovations in immersive interactive technologies are changing the way students explore Earth and its environment. State-of-the-art hardware has given developers the tools needed to capture high-resolution spherical content, 360° panoramic video, giga-pixel imagery, and unique viewpoints via unmanned aerial vehicles as they explore remote and physically challenging regions of our planet. Advanced software enables integration of these data into seamless, dynamic, immersive, interactive, content-rich, and learner-driven virtual field explorations, experienced online via HTML5. These surpass conventional online exercises that use 2-D static imagery and enable the student to engage in these virtual environments that are more like games than like lectures. Grounded in the active learning of exploration, inquiry, and application of knowledge as it is acquired, users interact non-linearly in conjunction with an intelligent tutoring system (ITS). The integration of this system allows the educational experience to be adapted to each individual student as they interact within the program. Such explorations, which we term "immersive virtual field trips" (iVFTs), are being integrated into cyber-learning allowing science teachers to take students to scientifically significant but inaccessible environments. Our team and collaborators are producing a diverse suite of freely accessible, iVFTs to teach key concepts in geology, astrobiology, ecology, and anthropology. Topics include Early Life, Biodiversity, Impact craters, Photosynthesis, Geologic Time, Stratigraphy, Tectonics, Volcanism, Surface Processes, The Rise of Oxygen, Origin of Water, Early Civilizations, Early Multicellular Organisms, and Bioarcheology. These diverse topics allow students to experience field sites all over the world, including, Grand Canyon (USA), Flinders Ranges (Australia), Shark Bay (Australia), Rainforests (Panama), Teotihuacan (Mexico), Upheaval Dome (USA), Pilbara (Australia), Mid-Atlantic Ridge

Particle Swarm-Based Translation Control for Immersed Tunnel Element in the Hong Kong-Zhuhai-Macao Bridge Project

Science.gov (United States)

Li, Jun-jun; Yang, Xiao-jun; Xiao, Ying-jie; Xu, Bo-wei; Wu, Hua-feng

2018-03-01

Immersed tunnel is an important part of the Hong Kong-Zhuhai-Macao Bridge (HZMB) project. In immersed tunnel floating, translation which includes straight and transverse movements is the main working mode. To decide the magnitude and direction of the towing force for each tug, a particle swarm-based translation control method is presented for non-power immersed tunnel element. A sort of linear weighted logarithmic function is exploited to avoid weak subgoals. In simulation, the particle swarm-based control method is evaluated and compared with traditional empirical method in the case of the HZMB project. Simulation results show that the presented method delivers performance improvement in terms of the enhanced surplus towing force.

Low leaching and low LWR photoresist development for 193 nm immersion lithography

Science.gov (United States)

Ando, Nobuo; Lee, Youngjoon; Miyagawa, Takayuki; Edamatsu, Kunishige; Takemoto, Ichiki; Yamamoto, Satoshi; Tsuchida, Yoshinobu; Yamamoto, Keiko; Konishi, Shinji; Nakano, Katsushi; Tomoharu, Fujiwara

2006-03-01

With no apparent showstopper in sight, the adoption of ArF immersion technology into device mass production is not a matter of 'if' but a matter of 'when'. As the technology matures at an unprecedented speed, many of initial technical difficulties have been cleared away and the use of a protective layer known as top coat, initially regarded as a must, now becomes optional, for example. Our focus of interest has also sifted to more practical and production related issues such as defect reducing and performance enhancement. Two major types of immersion specific defects, bubbles and a large number of microbridges, were observed and reported elsewhere. The bubble defects seem to decrease by improvement of exposure tool. But the other type defect - probably from residual water spots - is still a problem. We suspect that the acid leaching from resist film causes microbridges. When small water spots were remained on resist surface after exposure, acid catalyst in resist film is leaching into the water spots even though at room temperature. After water from the spot is dried up, acid molecules are condensed at resist film surface. As a result, in the bulk of resist film, acid depletion region is generated underneath the water spot. Acid catalyzed deprotection reaction is not completed at this acid shortage region later in the PEB process resulting in microbridge type defect formation. Similar mechanism was suggested by Kanna et al, they suggested the water evaporation on PEB plate. This hypothesis led us to focus on reducing acid leaching to decrease residual water spot-related defect. This paper reports our leaching measurement results and low leaching photoresist materials satisfying the current leaching requirements outlined by tool makers without topcoat layer. On the other hand, Nakano et al reported that the higher receding contact angle reduced defectivity. The higher receding contact angle is also a key item to increase scan speed. The effort to increase the

Tracheal injury added to cervical bone destruction due to the impact of hitting the water surface: four immersed adult bodies.

Science.gov (United States)

Zuka, Masahiko; Ohshima, Tohru

2013-05-10

In the forensic examinations of cases of falling, two properties of the water surface, namely its nature as a hard, flat object and as a soft and ungraspable substance must be appreciated. Namely, at the moment of impact, the water surface exerts a greater resistance against relatively broad areas like the head, face and trunk than against the extremities that have a small area. Therefore, total resistance against the whole body would promote flexure. We experienced 72 autopsy cases of immersed bodies during a 4-year period. The cause of death for 64 of these with or without cervical vertebra fracture was drowning. In these cases, the various heights of the falls could often be estimated at the scene. A characteristic pattern of cervical injury with involvement of hyoid bone and thyroid cartilage in addition to cervical vertebra fracture plus rare involvement of the trachea was identified. When a fall from a relatively low height is broken by the water surface, to a certain degree physical findings that differ from those seen in falls to the ground from extreme heights are left mediated by different underlying mechanisms. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Light-absorbent liquid immersion angled exposure for patterning 3D samples with vertical sidewalls

International Nuclear Information System (INIS)

Kumagai, Shinya; Kubo, Hironori; Sasaki, Minoru

2017-01-01

To make photolithography patterns on 3D samples, the angled (inclined) exposure technique has been used so far. However, technological issues have emerged in making photolithography patterns on the surface of trench structures. The surface of the trench structures can be covered with a photoresist film by spray-coating but the photoresist film deposited on the sidewalls and bottom of the trench is generally thin. The thin photoresist film deposited inside the trench has been easily overdosed. Moreover, irregular patterns have frequently been formed by the light reflected inside the trench. In this study, we have developed liquid immersion photolithography using a light-absorbent material. The light-reflection inside the trench was suppressed. Various patterns were transferred in the photoresist film deposited on the trench structures which had an aspect ratio of 0.74. Compared to immersion photolithography using pure water under p -polarization light control, the light-absorbent liquid immersion photolithography developed here patterned well the surfaces of the trench sidewalls and bottom. (paper)

46 CFR 199.214 - Immersion suits and thermal protective aids.

Science.gov (United States)

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Immersion suits and thermal protective aids. 199.214... Passenger Vessels § 199.214 Immersion suits and thermal protective aids. (a) Each passenger vessel must... an immersion suit. (c) The immersion suits and thermal protective aids required under paragraphs (a...

Approach to the surface characteristics of the H+ and H+-La3+ forms of cation-exchange resins by measurement of the heat of immersion

International Nuclear Information System (INIS)

Suzuki, T.; Uematsu, T.

1985-01-01

Surface characteristics of H + and its multivalent cation-exchanged resins, which have been used as catalysts, were probed by measurement of the heats of immersion in 1-nitropropane, n-hexane, and water. It was found that the electrostatic field strengths (F) calculated from the heats of immersion in 1-nitropropane and n-hexane increased with increasing ratios of the exchanged multivalent cation (La 3+ ) in the univalent form (H + ) cation-exchange resin. This tendency was also observed in the differences in F between the La 3+ exchanged resins and H + form of the resin by using the calorimetric data obtained from the heats of immersion in water. These results suggest that the exchanged La 3 μ ion does not homogeneously interact with three univalent anionic sites (SO 3 - ) of the cation-exchange resin, but interacts with only two SO 3 - ions, that is, the La 3+ ion is localized on the surface of the resin. The difference in F obtained from the heats of immersion into water was found to be useful as a simple and rapid criterion of the surface characteristics of the cation-exchange resins. 18 references, 4 figures, 1 table

Photonic crystal fiber coil sensor for water-depth sensing

Science.gov (United States)

Fan, Chen-Feng; Yu, Chin-Ping

2013-05-01

We fabricate a PCF coil sensor for water-depth sensing by winding a PCF on a plastic straw. Due to the bending-induced birefringence along the PCF, we can observe clear interference pattern in the output spectrum by placing the PCF coil into a Sagnac fiber loop. As we horizontally immerse the fabricated PCF coil into water, a nonlinear relationship between the water depth and the wavelength shift can be obtained. We have also measured the interference spectrum by vertically immersing the PCF coil into water. We can observe a linear relationship between the water depth and the wavelength shift, and the measured water-depth sensitivity for vertical immersion is -1.17 nm/mm.

The Balancing Act of Bilingual Immersion

Science.gov (United States)

Hadi-Tabassum, Samina

2005-01-01

Hadi-Tabassum believes having a separate life context for each language she learned in childhood enabled her to switch easily among five different tongues. She states that the success of dual immersion bilingual programs is largely dependent on whether they immerse students in each of the involved languages separately and help students have a…

SHORT-TERM AND LONG-TERM WATER LEVEL PREDICTION AT ONE RIVER MEASUREMENT LOCATION

Directory of Open Access Journals (Sweden)

Rudolf Scitovski

2012-12-01

Full Text Available Global hydrological cycles mainly depend on climate changes whose occurrence is predominantly triggered by solar and terrestrial influence, and the knowledge of the high water regime is widely applied in hydrology. Regular monitoring and studying of river water level behavior is important from several perspectives. On the basis of the given data, by using modifications of general approaches known from literature, especially from investigation in hydrology, the problem of long- and short-term water level forecast at one river measurement location is considered in the paper. Long-term forecasting is considered as the problem of investigating the periodicity of water level behavior by using linear-trigonometric regression and short-term forecasting is based on the modification of the nearest neighbor method. The proposed methods are tested on data referring to the Drava River level by Donji Miholjac, Croatia, in the period between the beginning of 1900 and the end of 2012.

Thermal comfort following immersion.

Science.gov (United States)

Guéritée, Julien; Redortier, Bernard; House, James R; Tipton, Michael J

2015-02-01

Unlike thermal comfort in air, little research has been undertaken exploring thermal comfort around water sports. We investigated the impact of swimming and cooling in air after swimming on thermal comfort. After 10 min of swimming-and-resting cycles in 28°C water, volunteers wearing two types of garments or in swim briefs, faced winds in 24°C air, at rest or when stepping. Thermal comfort was significantly higher during swimming than resting. Post-immersion, following maximum discomfort, in 45 of 65 tests thermal comfort improved although mean skin temperature was still cooling (0.26 [SD 0.19] °C·min(-1) - max was 0.89°C·min(-1)). When thermal comfort was re-established mean skin temperature was lower than at maximal discomfort in 39 of 54 tests (0.81 [SD 0.58] °C - max difference was 2.68°C). The reduction in thermal discomfort in this scenario could be due to the adaptation of thermoreceptors, or to reductions in cooling rates to levels where discomfort was less stimulated. The relief from the recent discomfort may explain why, later, thermal comfort returned to initial levels in spite of poorer thermal profiles. Copyright © 2014 Elsevier Inc. All rights reserved.

Micromachined capacitive ultrasonic immersion transducer array

Science.gov (United States)

Jin, Xuecheng

Capacitive micromachined ultrasonic transducers (cMUTs) have emerged as an attractive alternative to conventional piezoelectric ultrasonic transducers. They offer performance advantages of wide bandwidth and sensitivity that have heretofore been attainable. In addition, micromachining technology, which has benefited from the fast-growing microelectronics industry, enables cMUT array fabrication and electronics integration. This thesis describes the design and fabrication of micromachined capacitive ultrasonic immersion transducer arrays. The basic transducer electrical equivalent circuit is derived from Mason's theory. The effects of Lamb waves and Stoneley waves on cross coupling and acoustic losses are discussed. Electrical parasitics such as series resistance and shunt capacitance are also included in the model of the transducer. Transducer fabrication technology is systematically studied. Device dimension control in both vertical and horizontal directions, process alternatives and variations in membrane formation, via etch and cavity sealing, and metalization as well as their impact on transducer performance are summarized. Both 64 and 128 element 1-D array transducers are fabricated. Transducers are characterized in terms of electrical input impedance, bandwidth, sensitivity, dynamic range, impulse response and angular response, and their performance is compared with theoretical simulation. Various schemes for cross coupling reduction is analyzed, implemented, and verified with both experiments and theory. Preliminary results of immersion imaging are presented using 64 elements 1-D array transducers for active source imaging.

Aerosol behavior and light water reactor source terms

International Nuclear Information System (INIS)

Abbey, F.; Schikarski, W.O.

1988-01-01

The major developments in nuclear aerosol modeling following the accident to pressurized water reactor Unit 2 at Three Mile Island are briefly reviewed and the state of the art summarized. The importance and implications of these developments for severe accident source terms for light water reactors are then discussed in general terms. The treatment is not aimed at identifying specific source term values but is intended rather to illustrate trends, to assess the adequacy of the understanding of major aspects of aerosol behavior for source term prediction, and demonstrate in qualitative terms the effect of various aspects of reactor design. Areas where improved understanding of aerosol behavior might lead to further reductions in current source terms predictions are also considered

Metal ion implantation: Conventional versus immersion

International Nuclear Information System (INIS)

Brown, I.G.; Anders, A.; Anders, S.; Dickinson, M.R.; MacGill, R.A.

1994-01-01

Vacuum-arc-produced metal plasma can be used as the ion feedstock material in an ion source for doing conventional metal ion implantation, or as the immersing plasma for doing plasma immersion ion implantation. The basic plasma production method is the same in both cases; it is simple and efficient and can be used with a wide range of metals. Vacuum arc ion sources of different kinds have been developed by the authors and others and their suitability as a metal ion implantation tool has been well established. Metal plasma immersion surface processing is an emerging tool whose characteristics and applications are the subject of present research. There are a number of differences between the two techniques, both in the procedures used and in the modified surfaces created. For example, the condensibility of metal plasma results in thin film formation and subsequent energetic implantation is thus done through the deposited layer; in the usual scenario, this recoil implantation and the intermixing it produces is a feature of metal plasma immersion but not of conventional energetic ion implantation. Metal plasma immersion is more suited (but not limited) to higher doses (>10 17 cm -2 ) and lower energies (E i < tens of keV) than the usual ranges of conventional metal ion implantation. These and other differences provide these vacuum-arc-based surface modification tools with a versatility that enhances the overall technological attractiveness of both

Story Immersion in a Health Videogame for Childhood Obesity Prevention.

Science.gov (United States)

Lu, Amy Shirong; Thompson, Debbe; Baranowski, Janice; Buday, Richard; Baranowski, Tom

2012-02-15

Stories can serve as powerful tools for health interventions. Story immersion refers to the experience of being absorbed in a story. This is among the first studies to analyze story immersion's role in health videogames among children by addressing two main questions: Will children be more immersed when the main characters are similar to them? Do increased levels of immersion relate to more positive health outcomes? Eighty-seven 10-12-year-old African-American, Caucasian, and Hispanic children from Houston, TX, played a health videogame, "Escape from Diab" (Archimage, Houston, TX), featuring a protagonist with both African-American and Hispanic phenotypic features. Children's demographic information, immersion, and health outcomes (i.e., preference, motivation, and self-efficacy) were recorded and then correlated and analyzed. African-American and Hispanic participants reported higher immersion scores than Caucasian participants ( P = 0.01). Story immersion correlated positively ( P values videogame characters and players enhanced immersion and several health outcomes. Effectively embedding characters with similar phenotypic features to the target population in interactive health videogame narratives may be important when motivating children to adopt obesity prevention behaviors.

Cold-Water Immersion Cooling Rates in Football Linemen and Cross-Country Runners With Exercise-Induced Hyperthermia.

Science.gov (United States)

Godek, Sandra Fowkes; Morrison, Katherine E; Scullin, Gregory

2017-10-01

  Ideal and acceptable cooling rates in hyperthermic athletes have been established in average-sized participants. Football linemen (FBs) have a small body surface area (BSA)-to-mass ratio compared with smaller athletes, which hinders heat dissipation.   To determine cooling rates using cold-water immersion in hyperthermic FBs and cross-country runners (CCs).   Cohort study.   Controlled university laboratory.   Nine FBs (age = 21.7 ± 1.7 years, height = 188.7 ± 4 cm, mass = 128.1 ± 18 kg, body fat = 28.9% ± 7.1%, lean body mass [LBM] = 86.9 ± 19 kg, BSA = 2.54 ± 0.13 m 2 , BSA/mass = 201 ± 21.3 cm 2 /kg, and BSA/LBM = 276.4 ± 19.7 cm 2 /kg) and 7 CCs (age = 20 ± 1.8 years, height = 176 ± 4.1 cm, mass = 68.7 ± 6.5 kg, body fat = 10.2% ± 1.6%, LBM = 61.7 ± 5.3 kg, BSA = 1.84 ± 0.1 m 2 , BSA/mass = 268.3 ± 11.7 cm 2 /kg, and BSA/LBM = 298.4 ± 11.7 cm 2 /kg).   Participants ingested an intestinal sensor, exercised in a climatic chamber (39°C, 40% relative humidity) until either target core temperature (T gi ) was 39.5°C or volitional exhaustion was reached, and were immediately immersed in a 10°C circulated bath until T gi declined to 37.5°C. A general linear model repeated-measures analysis of variance and independent t tests were calculated, with P LBM/mass (r = 0.72, P LBM (r = -0.72, P 11 minutes) than smaller, leaner athletes (7.7 minutes). Cooling rates varied widely from 0.332°C·min -1 in a small runner to only 0.101°C·min -1 in a lineman, supporting the use of rectal temperature for monitoring during cooling.

Evaluation of the Influence of Jiangxiang Reservoir Immersion on Corp and Residential Areas

Directory of Open Access Journals (Sweden)

Jing Chen

2018-01-01

Full Text Available Reservoir immersion is an environmental geological issue. Jiangxiang reservoir was taken as an example, where both analytical and numerical methods were employed to calculate the banked-up water level after reservoir impoundment, based on the hydrological, meteorological, geological, and hydrogeological conditions. The capillary rise height of soils in the reservoir area was determined through in situ measurement and laboratory analysis. The depth of foundation and crop roots in residential areas can be obtained by field investigation. The critical depth to groundwater was calculated according to the height of capillary rise and land elevation. Furthermore, the influence of reservoir immersion was evaluated, which provides a scientific basis for the relocation of people in reservoir areas, planting of crops, and project investment.

Evaluation of Anisotropic Biaxial Stress Induced Around Trench Gate of Si Power Transistor Using Water-Immersion Raman Spectroscopy

Science.gov (United States)

Suzuki, Takahiro; Yokogawa, Ryo; Oasa, Kohei; Nishiwaki, Tatsuya; Hamamoto, Takeshi; Ogura, Atsushi

2018-05-01

The trench gate structure is one of the promising techniques to reduce on-state resistance (R on) for silicon power devices, such as insulated gate bipolar transistors and power metal-oxide-semiconductor field-effect transistors. In addition, it has been reported that stress is induced around the trench gate area, modifying the carrier mobilities. We evaluated the one-dimensional distribution and anisotropic biaxial stress by quasi-line excitation and water-immersion Raman spectroscopy, respectively. The results clearly confirmed anisotropic biaxial stress in state-of-the-art silicon power devices. It is theoretically possible to estimate carrier mobility using piezoresistance coefficients and anisotropic biaxial stress. The electron mobility was increased while the hole mobility was decreased or remained almost unchanged in the silicon (Si) power device. The stress significantly modifies the R on of silicon power transistors. Therefore, their performance can be improved using the stress around the trench gate.

Comparison of thermoregulatory responses to heat between Malaysian and Japanese males during leg immersion

Science.gov (United States)

Wijayanto, Titis; Wakabayashi, Hitoshi; Lee, Joo-Young; Hashiguchi, Nobuko; Saat, Mohamed; Tochihara, Yutaka

2011-07-01

The objective of this study was to investigate thermoregulatory responses to heat in tropical (Malaysian) and temperate (Japanese) natives, during 60 min of passive heating. Ten Japanese (mean ages: 20.8 ± 0.9 years) and ten Malaysian males (mean ages: 22.3 ± 1.6 years) with matched morphological characteristics and physical fitness participated in this study. Passive heating was induced through leg immersion in hot water (42°C) for 60 min under conditions of 28°C air temperature and 50% RH. Local sweat rate on the forehead and thigh were significantly lower in Malaysians during leg immersion, but no significant differences in total sweat rate were observed between Malaysians (86.3 ± 11.8 g m-2 h-1) and Japanese (83.2 ± 6.4 g m-2 h-1) after leg immersion. In addition, Malaysians displayed a smaller rise in rectal temperature (0.3 ± 0.1°C) than Japanese (0.7 ± 0.1°C) during leg immersion, with a greater increase in hand skin temperature. Skin blood flow was significantly lower on the forehead and forearm in Malaysians during leg immersion. No significant different in mean skin temperature during leg immersion was observed between the two groups. These findings indicated that regional differences in body sweating distribution might exist between Malaysians and Japanese during heat exposure, with more uniform distribution of local sweat rate over the whole body among tropical Malaysians. Altogether, Malaysians appear to display enhanced efficiency of thermal sweating and thermoregulatory responses in dissipating heat loss during heat loading. Thermoregulatory differences between tropical and temperate natives in this study can be interpreted as a result of heat adaptations to physiological function.

Flexural strength of fluorapatite-leucite and fuorapatite porcelains exposed to erosive agents in cyclic immersion

Directory of Open Access Journals (Sweden)

Peerapong Junpoom

2011-04-01

Full Text Available OBJECTIVE: The aim of this study was to evaluate the fexural strength of two porcelain materials (IPS d.SIGN and IPS e.max Ceram exposed to erosive agents. MATERIAL AND METHODS: One hundred and twenty bar-shaped specimens were made from each of fuorapatite-leucite porcelain (IPS d.SIGN and fuorapatite porcelain (IPS e.max Ceram and divided into 8 groups of 15 specimens each. Six groups were alternately immersed in the following storage agents for 30 min: deionized water (control, citrate buffer solution, pineapple juice, green mango juice, cola soft drink and 4% acetic acid. Then, they were immersed for 5 min in deionized water at 37ºC. Seven cycles were completed, totalizing 245 min. A 7th group was continuously immersed in 4% acetic acid at 80ºC for 16 h. The final, 8th, group was stored dry at 37ºC for 245 min. Three-point bending tests were performed in a universal testing machine. The data were analyzed statistically by 2-way ANOVA, Tukey's HSD test and t-test at signifcance level of 0.05. RESULTS: The fexural strengths of all groups of each porcelain after exposure to erosive agents in cyclic immersion did not differ signifcantly (p>0.05. For both types of porcelain, dry storage at 37ºC yielded the highest fexural strength, though without signifcant difference from the other groups (p>0.05. The fexural strengths of all groups of fuorapatite porcelains were signifcantly higher (p<0.05 than those of the fuorapatite-leucite porcelains. CONCLUSIONS: This study demonstrated that the erosive agents evaluated did not affect the fexural strength of the tested dental porcelains.

Immersive Training Systems: Virtual Reality and Education and Training.

Science.gov (United States)

Psotka, Joseph

1995-01-01

Describes virtual reality (VR) technology and VR research on education and training. Focuses on immersion as the key added value of VR, analyzes cognitive variables connected to immersion, how it is generated in synthetic environments and its benefits. Discusses value of tracked, immersive visual displays over nonimmersive simulations. Contains 78…

Synthetic sea water - An improved stress corrosion test medium for aluminum alloys

Science.gov (United States)

Humphries, T. S.; Nelson, E. E.

1973-01-01

A major problem in evaluating the stress corrosion cracking resistance of aluminum alloys by alternate immersion in 3.5 percent salt (NaCl) water is excessive pitting corrosion. Several methods were examined to eliminate this problem and to find an improved accelerated test medium. These included the addition of chromate inhibitors, surface treatment of specimens, and immersion in synthetic sea water. The results indicate that alternate immersion in synthetic sea water is a very promising stress corrosion test medium. Neither chromate inhibitors nor surface treatment (anodize and alodine) of the aluminum specimens improved the performance of alternate immersion in 3.5 percent salt water sufficiently to be classified as an effective stress corrosion test method.

Immersive virtual reality in traumatic brain injury rehabilitation: A literature review.

Science.gov (United States)

Aida, Jared; Chau, Brian; Dunn, Justin

2018-04-07

Traumatic brain injury (TBI) is a common cause of morbidity and mortality in the United States with its sequelae often affecting individuals long after the initial injury. Innovations in virtual reality (VR) technology may offer potential therapy options in the recovery from such injuries. However, there is currently no consensus regarding the efficacy of VR in the setting of TBI rehabilitation. The aim of this review is to evaluate and summarize the current literature regarding immersive VR in the rehabilitation of those with TBI. A comprehensive literature search was conducted utilizing PubMed, Google Scholar, and the Cochrane Review using the search terms "virtual reality," "traumatic brain injury," "brain injury," and "immersive." A total of 11 studies were evaluated. These were primarily of low-level evidence, with the exception of two randomized, controlled trials. 10 of 11 studies demonstrated improvement with VR therapy. VR was most frequently used to address gait or cognitive deficits. While the current literature generally offers support for the use of VR in TBI recovery, there is a paucity of strong evidence to support its widespread use. The increasing availability of immersive VR technology offers the potential for engaging therapy in TBI rehabilitation, but its utility remains uncertain given the limited studies available at this time.

Story Immersion in a Health Videogame for Childhood Obesity Prevention

Science.gov (United States)

Thompson, Debbe; Baranowski, Janice; Buday, Richard; Baranowski, Tom

2012-01-01

Abstract Objective Stories can serve as powerful tools for health interventions. Story immersion refers to the experience of being absorbed in a story. This is among the first studies to analyze story immersion's role in health videogames among children by addressing two main questions: Will children be more immersed when the main characters are similar to them? Do increased levels of immersion relate to more positive health outcomes? Subjects and Methods Eighty-seven 10–12-year-old African-American, Caucasian, and Hispanic children from Houston, TX, played a health videogame, “Escape from Diab” (Archimage, Houston, TX), featuring a protagonist with both African-American and Hispanic phenotypic features. Children's demographic information, immersion, and health outcomes (i.e., preference, motivation, and self-efficacy) were recorded and then correlated and analyzed. Results African-American and Hispanic participants reported higher immersion scores than Caucasian participants (P=0.01). Story immersion correlated positively (P valuesvideogame characters and players enhanced immersion and several health outcomes. Effectively embedding characters with similar phenotypic features to the target population in interactive health videogame narratives may be important when motivating children to adopt obesity prevention behaviors. PMID:24066276

Exploring the Design Space of Immersive Urban Analytics

OpenAIRE

Chen, Zhutian; Wang, Yifang; Sun, Tianchen; Gao, Xiang; Chen, Wei; Pan, Zhigeng; Qu, Huamin; Wu, Yingcai

2017-01-01

Recent years have witnessed the rapid development and wide adoption of immersive head-mounted devices, such as HTC VIVE, Oculus Rift, and Microsoft HoloLens. These immersive devices have the potential to significantly extend the methodology of urban visual analytics by providing critical 3D context information and creating a sense of presence. In this paper, we propose an theoretical model to characterize the visualizations in immersive urban analytics. Further more, based on our comprehensiv...

The immersion freezing behavior of size-segregated soot and kaolinite particles

Science.gov (United States)

Hartmann, S.; Augustin, S.; Clauss, T.; Niedermeier, D.; Raddatz, M.; Wex, H.; Shaw, R. A.; Stratmann, F.

2011-12-01

Heterogeneous ice nucleation plays a crucial role for ice formation in mixed-phase and cirrus clouds and has an important impact on precipitation formation, global radiation balances, and therefore Earth's climate (Cantrell and Heymsfield, 2005). Mineral dust and soot particles are found to be a major component of ice crystal residues (e.g., Pratt et al., 2009) so these substances are potential sources of atmospheric ice nuclei (IN). Experimental studies investigating the immersion freezing behavior of size-segregated soot and kaolinite particles conducted at the Leipzig Aerosol Cloud Interaction Simulator (LACIS) are presented. In our measurements only one aerosol particle is immersed in an air suspended water droplet which can trigger ice nucleation. The method facilitates very precise examinations with respect to temperature, ice nucleation time and ice nucleus size. Considering laboratory studies, the picture of the IN ability of soot particles is quite heterogeneous. Our studies show that submicron flame, spark soot particles and optionally coated with sulfuric acid to simulate chemically aging do not act as IN at temperatures higher than homogeneous freezing taking place. Therefore soot particles might not be an important source of IN for immersion freezing in the atmosphere. In contrast, kaolinite being representative for natural mineral dust with a well known composition and structure is found to be very active in forming ice for all freezing modes (e.g., Mason and Maybank, 1958). Analyzing the immersion freezing behavior of different sized kaolinite particles (300, 500 and 700 nm in diameter) the size effect was clearly observed, i.e. the ice fraction (number of frozen droplets per total number) scales with particle surface, i.e. the larger the ice nucleus surface the higher the ice fraction. The slope of the logarithm of the ice fraction as function of temperature is similar for all particle sizes investigated and fits very well with the results of L�

Fully Noncontact Wave Propagation Imaging in an Immersed Metallic Plate with a Crack

Directory of Open Access Journals (Sweden)

Jung-Ryul Lee

2014-01-01

Full Text Available This study presents a noncontact sensing technique with ultrasonic wave propagation imaging algorithm, for damage visualization of liquid-immersed structures. An aluminum plate specimen (400 mm × 400 mm × 3 mm with a 12 mm slit was immersed in water and in glycerin. A 532 nm Q-switched continuous wave laser is used at an energy level of 1.2 mJ to scan an area of 100 mm × 100 mm. A laser Doppler vibrometer is used as a noncontact ultrasonic sensor, which measures guided wave displacement at a fixed point. The tests are performed with two different cases of specimen: without water and filled with water and with glycerin. Lamb wave dispersion curves for the respective cases are calculated, to investigate the velocity-frequency relationship of each wave mode. Experimental propagation velocities of Lamb waves for different cases are compared with the theoretical dispersion curves. This study shows that the dispersion and attenuation of the Lamb wave is affected by the surrounding liquid, and the comparative experimental results are presented to verify it. In addition, it is demonstrated that the developed fully noncontact ultrasonic propagation imaging system is capable of damage sizing in submerged structures.

Can Cold Water Immersion Enhance Recovery in Elite Olympic Weightlifters? An Individualized Perspective.

Science.gov (United States)

Schimpchen, Jan; Wagner, Maximilian; Ferrauti, Alexander; Kellmann, Michael; Pfeiffer, Mark; Meyer, Tim

2017-06-01

We investigated whether cold water immersion (CWI) after intensive training sessions can enhance recovery in elite Olympic weightlifters, taking into account each athlete's individual response pattern. The entire German male Olympic weightlifting national team participated in the study (n = 7), ensuring collection of data from elite athletes only. Using a randomized cross-over design, the athletes went through 2 high-intensity training microcycles consisting of 5 training sessions that were either followed by a CWI or passive recovery. Barbell speed in a snatch pull movement, blood parameters, and subjective ratings of general fatigue and recovery were assessed throughout the study. Physical performance at 2 snatch pull intensities (85% one repetition maximum [1RM]: -0.15% vs. -0.22%, p = 0.94; 90% 1RM: -0.7% vs. +1.23%, p = 0.25) did not differ significantly (condition × time). Although questionnaires revealed a significant decline in the ratings of overall recovery (p creatine kinase: p = 0.53; urea: p = 0.43; cortisol: p = 0.59; testosterone: p = 0.53; testosterone:cortisol ratio: p = 0.69). In general, CWI did not prove to be an effective tool to enhance recovery in elite Olympic weightlifters over a 3-day intensive training period. However, even though the group was rather homogeneous with regard to performance, there were considerable intersubject differences in their response to CWI. It seems that athletes are best advised on a case-by-case basis.

Recovery From Exercise-Induced Muscle Damage: Cold-Water Immersion Versus Whole-Body Cryotherapy.

Science.gov (United States)

Abaïdia, Abd-Elbasset; Lamblin, Julien; Delecroix, Barthélémy; Leduc, Cédric; McCall, Alan; Nédélec, Mathieu; Dawson, Brian; Baquet, Georges; Dupont, Grégory

2017-03-01

To compare the effects of cold-water immersion (CWI) and whole-body cryotherapy (WBC) on recovery kinetics after exercise-induced muscle damage. Ten physically active men performed single-leg hamstring eccentric exercise comprising 5 sets of 15 repetitions. Immediately postexercise, subjects were exposed in a randomized crossover design to CWI (10 min at 10°C) or WBC (3 min at -110°C) recovery. Creatine kinase concentrations, knee-flexor eccentric (60°/s) and posterior lower-limb isometric (60°) strength, single-leg and 2-leg countermovement jumps, muscle soreness, and perception of recovery were measured. The tests were performed before and immediately, 24, 48, and 72 h after exercise. Results showed a very likely moderate effect in favor of CWI for single-leg (effect size [ES] = 0.63; 90% confidence interval [CI] = -0.13 to 1.38) and 2-leg countermovement jump (ES = 0.68; 90% CI = -0.08 to 1.43) 72 h after exercise. Soreness was moderately lower 48 h after exercise after CWI (ES = -0.68; 90% CI = -1.44 to 0.07). Perception of recovery was moderately enhanced 24 h after exercise for CWI (ES = -0.62; 90% CI = -1.38 to 0.13). Trivial and small effects of condition were found for the other outcomes. CWI was more effective than WBC in accelerating recovery kinetics for countermovement-jump performance at 72 h postexercise. CWI also demonstrated lower soreness and higher perceived recovery levels across 24-48 h postexercise.

Effect of finishing and polishing on the color stability of a composite resin immersed in staining solutions

Directory of Open Access Journals (Sweden)

Maiara Justo Polli

2015-01-01

Full Text Available Objective: To evaluate the influence of finishing/polishing methods and staining solutions using different immersion periods on the color stability of a microhybrid composite resin. Materials and Methods: Ninety specimens were fabricated using a stainless steel mold and polyester strips. The samples were randomly divided into five groups according to the finishing and polishing performed: Control group (no surface treatment was performed, Diamond Pro group, Diamond burs group, Enhance group, and SiC paper group. After finishing and polishing, six samples from each group were immersed in coffee, red wine, or water for 30 days. The color measurements were obtained using digital photography before immersion and after 7, 15, and 30 days of immersion. The red, green, and blue values provided by the Adobe Photoshop software were converted into CIELab values. A three-way analysis of variance and Tukey's test were used for statistical analysis (P ≤ 0.05. Results: The finishing and polishing methods, staining solutions, immersion times, and their interaction had statistically significant effects on the color change (P = 0.00. Coffee and red wine caused intense staining. Among the polishing methods, the highest color change value was observed in the control group (P < 0.05 and the Diamond Pro disks provided the most stain-resistant surfaces (P ≤ 0.05. Conclusion: The finishing and polishing method, staining solution, and immersion time influences the color stability. Finishing and polishing should be applied to obtain a more stain-resistant surface.

Lubricated immersed boundary method in two dimensions

Science.gov (United States)

Fai, Thomas G.; Rycroft, Chris H.

2018-03-01

Many biological examples of fluid-structure interaction, including the transit of red blood cells through the narrow slits in the spleen and the intracellular trafficking of vesicles into dendritic spines, involve the near-contact of elastic structures separated by thin layers of fluid. Motivated by such problems, we introduce an immersed boundary method that uses elements of lubrication theory to resolve thin fluid layers between immersed boundaries. We demonstrate 2nd-order accurate convergence for simple two-dimensional flows with known exact solutions to showcase the increased accuracy of this method compared to the standard immersed boundary method. Motivated by the phenomenon of wall-induced migration, we apply the lubricated immersed boundary method to simulate an elastic vesicle near a wall in shear flow. We also simulate the dynamics of a vesicle traveling through a narrow channel and observe the ability of the lubricated method to capture the vesicle motion on relatively coarse fluid grids.

Immersive Earth: Teaching Earth and Space with inexpensive immersive technology

Science.gov (United States)

Reiff, P. H.; Sumners, C.; Law, C. C.; Handron, K.

2003-12-01

In 1995 we pioneered "Space Update", the Digital Library for the rest of us", software that was so simple that a child could use it without a keyboard and yet would allow one-click updating of the daily earth and space science images without the dangers of having an open web browser on display. Thanks to NASA support, it allowed museums and schools to have a powerful exhibit for a tiny price. Over 40,000 disks in our series have been distributed so far to educators and the public. In 2003, with our partners we are again revolutionizing educational technology with a low-cost hardware and software solution to creating and displaying immersive content. Recently selected for funding as part of the REASoN competition, Immersive Earth is a partnership of scientists, museums, educators, and content providers. The hardware consists of a modest projector with a special fisheye lens to be used in an inflatable dome which many schools already have. This, coupled with a modest personal computer, can now easily project images and movies of earth and space, allows training students in 3-D content at a tiny fraction of the cost of a cave or fullscale dome theater. Another low-cost solution is the "Imove" system, where spherical movies can play on a personal computer, with the user changing the viewing direction with a joystick. We were the first to create immersive earth science shows, remain the leader in creating educational content that people want to see. We encourage people with "allsky" images or movies to bring it and see what it looks like inside a dome! Your content could be in our next show!

Comparison of water degradation of YBaCuO superconducting films made from different structures

International Nuclear Information System (INIS)

Chang, C.; Tsai, J.A.

1988-01-01

Immersion of YBaCuO superconducting films in water has shown a large difference in degradation between structures with and without silver. For the structures containing silver layers and depositing at a high temperature, superconducting films with zero resistance at 87 K remain superconductive at 77 K after 5 h immersion in water, with an increase in room-temperature film resistance by a factor of 4; the contact resistance remains low after 60 h of immersion, allowing the measurement at low temperatures. For the structures containing no silver and depositing at room temperature, the contact resistance rapidly increases with immersion times, making the measurement at 77 K difficult after 5 min of immersion. Changes in the sharpness of the superconductive transition, and structures of the films due to the water immersion are also compared

Effect of Immersion in Simulated Body Fluid on the Mechanical Properties and Biocompatibility of Sintered Fe–Mn-Based Alloys

Directory of Open Access Journals (Sweden)

Zhigang Xu

2016-12-01

Full Text Available Fe–Mn-based degradable biomaterials (DBMs are promising candidates for temporary implants such as cardiovascular stents and bone fixation devices. Identifying their mechanical properties and biocompatibility is essential to determine the feasibility of Fe–Mn-based alloys as DBMs. This study presents the tensile properties of two powder metallurgical processed Fe–Mn-based alloys (Fe–28Mn and Fe–28Mn-3Si, in mass percent as a function of immersion time in simulated body fluid (SBF. In addition, short-term cytotoxicity testing was performed to evaluate the in vitro biocompatibility of the sintered Fe–Mn-based alloys. The results reveal that an increase in immersion duration deteriorated the tensile properties of both the binary and ternary alloys. The tensile properties of the immersed alloys were severely degraded after being soaked in SBF for ≥45 days. The ion concentration in SBF released from the Fe–28Mn-3Si samples was higher than their Fe–28Mn counterparts after 7 days immersion. The preliminary cytotoxicity testing based on the immersed SBF medium after 7 days immersion suggested that both the Fe–28Mn-3Si and Fe–28Mn alloys presented a good biocompatibility in Murine fibroblast cells.

The ALIVE Project: Astronomy Learning in Immersive Virtual Environments

Science.gov (United States)

Yu, K. C.; Sahami, K.; Denn, G.

2008-06-01

The Astronomy Learning in Immersive Virtual Environments (ALIVE) project seeks to discover learning modes and optimal teaching strategies using immersive virtual environments (VEs). VEs are computer-generated, three-dimensional environments that can be navigated to provide multiple perspectives. Immersive VEs provide the additional benefit of surrounding a viewer with the simulated reality. ALIVE evaluates the incorporation of an interactive, real-time ``virtual universe'' into formal college astronomy education. In the experiment, pre-course, post-course, and curriculum tests will be used to determine the efficacy of immersive visualizations presented in a digital planetarium versus the same visual simulations in the non-immersive setting of a normal classroom, as well as a control case using traditional classroom multimedia. To normalize for inter-instructor variability, each ALIVE instructor will teach at least one of each class in each of the three test groups.

Deteriorating water clarity in shallow waters: Evidence from long term MODIS and in-situ observations

Science.gov (United States)

Shi, Kun; Zhang, Yunlin; Zhu, Guangwei; Qin, Boqiang; Pan, Delu

2018-06-01

Water clarity (Secchi disk depth: SDD), as a proxy of water transparency, provides important information on the light availability to the water or lake ecosystem. Shallow lakes have been experienced dramatic environmental and climatic change. This study demonstrated using combination of long-term MODIS and in-situ measurements to track the dynamics of SDD with these environmental and climate changes in shallow water environments. We selected a typical turbid shallow Lake Taihu as our case study. Based on MODIS-Aqua data, an empirical model for estimating SDD was developed and validated. Subsequently, we employed the proposed model to derive the spatial and temporal SDD distribution patterns of Lake Taihu from 2003 to 2015. Combining MODIS-derived SDD time series of 2003-2015 and long-term in-situ SDD observations dated back to 1993, we elucidated SDD long-term variation trends and driving mechanism. Deteriorating water clarity from the long-term SDD observations indicated that Lake Taihu became more and more turbid and water quality was decreasing. Increasing in cyanobacterial bloom area, as a result of decreasing in wind speed and eutrophication, may partially be responsible for the decreasing trend. A predicted future decrease in the wind speed in Lake Taihu region could enhance the formation of cyanobacterial blooms and consequently lead to a further decrease in water clarity. This study suggested that coupling remote sensing monitoring and long-term in-situ observations could provide robust evidence and new insights to elucidate long-term dynamics in aquatic ecosystem evolution.

Social Interaction Development through Immersive Virtual Environments

Science.gov (United States)

Beach, Jason; Wendt, Jeremy

2014-01-01

The purpose of this pilot study was to determine if participants could improve their social interaction skills by participating in a virtual immersive environment. The participants used a developing virtual reality head-mounted display to engage themselves in a fully-immersive environment. While in the environment, participants had an opportunity…

Vibration of an Offshore Structure Having the Form of a Hollow Column Partially Filled with Multiple Fluids and Immersed in Water

Directory of Open Access Journals (Sweden)

Hsien-Yuan Lin

2012-01-01

Full Text Available This paper employs the numerical assembly method (NAM to determine the exact frequency-response amplitudes of an offshore structure such as piles or towers having the form of a hollow column filled with multiple fluids, immersed in water, carrying an eccentric tip mass supported by a translational spring and/or a rotational spring, and subjected to a harmonic force. The hollow column is modeled as a Bernoulli-Euler cantilever beam fixed at the bottom. For the case of zero harmonic force, the simultaneous equations of the vibration system reduce to an eigenvalue problem so that the natural frequencies and mode shapes of the beam can also be obtained. The effect of height of filled fluids on the characteristics of free vibration is also presented.

A Study on Immersion and Presence of a Portable Hand Haptic System for Immersive Virtual Reality.

Science.gov (United States)

Kim, Mingyu; Jeon, Changyu; Kim, Jinmo

2017-05-17

This paper proposes a portable hand haptic system using Leap Motion as a haptic interface that can be used in various virtual reality (VR) applications. The proposed hand haptic system was designed as an Arduino-based sensor architecture to enable a variety of tactile senses at low cost, and is also equipped with a portable wristband. As a haptic system designed for tactile feedback, the proposed system first identifies the left and right hands and then sends tactile senses (vibration and heat) to each fingertip (thumb and index finger). It is incorporated into a wearable band-type system, making its use easy and convenient. Next, hand motion is accurately captured using the sensor of the hand tracking system and is used for virtual object control, thus achieving interaction that enhances immersion. A VR application was designed with the purpose of testing the immersion and presence aspects of the proposed system. Lastly, technical and statistical tests were carried out to assess whether the proposed haptic system can provide a new immersive presence to users. According to the results of the presence questionnaire and the simulator sickness questionnaire, we confirmed that the proposed hand haptic system, in comparison to the existing interaction that uses only the hand tracking system, provided greater presence and a more immersive environment in the virtual reality.

A Study on Immersion and Presence of a Portable Hand Haptic System for Immersive Virtual Reality

Science.gov (United States)

Kim, Mingyu; Jeon, Changyu; Kim, Jinmo

2017-01-01

This paper proposes a portable hand haptic system using Leap Motion as a haptic interface that can be used in various virtual reality (VR) applications. The proposed hand haptic system was designed as an Arduino-based sensor architecture to enable a variety of tactile senses at low cost, and is also equipped with a portable wristband. As a haptic system designed for tactile feedback, the proposed system first identifies the left and right hands and then sends tactile senses (vibration and heat) to each fingertip (thumb and index finger). It is incorporated into a wearable band-type system, making its use easy and convenient. Next, hand motion is accurately captured using the sensor of the hand tracking system and is used for virtual object control, thus achieving interaction that enhances immersion. A VR application was designed with the purpose of testing the immersion and presence aspects of the proposed system. Lastly, technical and statistical tests were carried out to assess whether the proposed haptic system can provide a new immersive presence to users. According to the results of the presence questionnaire and the simulator sickness questionnaire, we confirmed that the proposed hand haptic system, in comparison to the existing interaction that uses only the hand tracking system, provided greater presence and a more immersive environment in the virtual reality. PMID:28513545

Immersive Virtual Environments and Multisensory Interfaces

DEFF Research Database (Denmark)

Stenslie, Ståle

2009-01-01

Based on my work with virtual environments dating back to the early 1990s, and with practical and engineering limitations on building tactile bodysuits that enhance the sense of immersion within detailed and dynamic virtual worlds overcome, this paper will take as its subject the example of my...... immersive artwork the Erotogod experiment (2001). A key aspect of interaction and immersion for the participant was the use of tactile bodysuit. I will analyze the multisensory nature of this experience, how tactility was engendered and, in fact, engineered through a mixture of technologies and approaches....... The paper will focus on the multisensory aspect of my interfaces as they have evolved through my projects, discussing how engineering problems were overcome to enhance tactility, the experimentations with tactile technologies in order to engineer the right feeling, and what is involved in the multisensory...

Maintenance system for immersed seals, specifically for nuclear reactors

International Nuclear Information System (INIS)

Poindexter, A.M.; Ricks, H.E.

1977-01-01

The invention concerns the immersed seals of nuclear reactors and specifically a maintenance system for the immersed seals of the revolving closing plugs of liquid metal breeder nuclear reactors. A liquid sodium immersed joint may be located at a given place or be surrounded by heating elements so that the sodium stays liquid whilst the reactor is working. In other cases, the sodium in the immersed seal is allowed to solidify whilst the reactor is working, thereby increasing the efficiency of the seal. At all events, the sodium must be in a liquid state during reloading with fuel to enable the plug to turn. The invention consists in fitting an ultrasonic transducer to the closure head of the reactor vessel so that the vibration emitting surface directs these vibrations towards the immersed seals so as to detach the deposits of impurities on them and ensure the wetting of the metal surfaces of which they are formed. Additionally, an envelope that can be placed around the ultrasonic transducer in conjunction with a suction appliance provides a mechanism through which the impurities can be removed from the area of the immersed seal [fr

A water activity based model of heterogeneous ice nucleation kinetics for freezing of water and aqueous solution droplets.

Science.gov (United States)

Knopf, Daniel A; Alpert, Peter A

2013-01-01

Immersion freezing of water and aqueous solutions by particles acting as ice nuclei (IN) is a common process of heterogeneous ice nucleation which occurs in many environments, especially in the atmosphere where it results in the glaciation of clouds. Here we experimentally show, using a variety of IN types suspended in various aqueous solutions, that immersion freezing temperatures and kinetics can be described solely by temperature, T, and solution water activity, a(w), which is the ratio of the vapour pressure of the solution and the saturation water vapour pressure under the same conditions and, in equilibrium, equivalent to relative humidity (RH). This allows the freezing point and corresponding heterogeneous ice nucleation rate coefficient, J(het), to be uniquely expressed by T and a(w), a result we term the a(w) based immersion freezing model (ABIFM). This method is independent of the nature of the solute and accounts for several varying parameters, including cooling rate and IN surface area, while providing a holistic description of immersion freezing and allowing prediction of freezing temperatures, J(het), frozen fractions, ice particle production rates and numbers. Our findings are based on experimental freezing data collected for various IN surface areas, A, and cooling rates, r, of droplets variously containing marine biogenic material, two soil humic acids, four mineral dusts, and one organic monolayer acting as IN. For all investigated IN types we demonstrate that droplet freezing temperatures increase as A increases. Similarly, droplet freezing temperatures increase as the cooling rate decreases. The log10(J(het)) values for the various IN types derived exclusively by Tand a(w), provide a complete description of the heterogeneous ice nucleation kinetics. Thus, the ABIFM can be applied over the entire range of T, RH, total particulate surface area, and cloud activation timescales typical of atmospheric conditions. Lastly, we demonstrate that ABIFM can

Immersive 3D Geovisualization in Higher Education

Science.gov (United States)

Philips, Andrea; Walz, Ariane; Bergner, Andreas; Graeff, Thomas; Heistermann, Maik; Kienzler, Sarah; Korup, Oliver; Lipp, Torsten; Schwanghart, Wolfgang; Zeilinger, Gerold

2015-01-01

In this study, we investigate how immersive 3D geovisualization can be used in higher education. Based on MacEachren and Kraak's geovisualization cube, we examine the usage of immersive 3D geovisualization and its usefulness in a research-based learning module on flood risk, called GEOSimulator. Results of a survey among participating students…

Is Immersion of Any Value? Whether, and to What Extent, Game Immersion Experience during Serious Gaming Affects Science Learning

Science.gov (United States)

Cheng, Meng-Tzu; Lin, Yu-Wen; She, Hsiao-Ching; Kuo, Po-Chih

2017-01-01

Many studies have shown the positive impact of serious gaming on learning outcomes, but few have explored the relationships between game immersion and science learning. Accordingly, this study was conducted to investigate the effectiveness of learning by playing, as well as the dynamic process of game immersion experiences, and to further identify…

MINERAL WATERS IN RHEUMATOID ARTHRITIS

Directory of Open Access Journals (Sweden)

BORGES, TIAGO

2013-02-01

Full Text Available Background: Rheumatoid arthritis (RA is an autoimmune disorder affecting nearly 1% of adult population. First-line therapies include disease-modifying antirheumatic drugs, but creno-balneotherapyis often prescribed in rheumatic disorders and RA is no exception. Objectives: To know the efficacy of creno-balneotherapy in RA. Methods: A Medline based search was made using MeSH terms “balneology” and “rheumatoid arthritis”. Articles concerning the use of mineral waters in RA treatment were included. Results: In RA, two traditional ways of employing mineral waters are commonly used: immersion and peliotherapy. Each owns their benefits to non-specific or hydrotherapeutic effects and specific or crenotherapeutic effects. Mineral waters must be regarded as an adjuvant therapy in quiescent, stable or non-progressive RA. Significant benefits have been accomplished with radonenriched and sulphurous waters. Isothermal or hyperthermal waters should be preferred. Conclusions: Although there is a global lack of evidence, mineral waters are a safe and effective therapy to be considered in RA.

Efficacy of DNA vaccine encoding koi herpesvirus glycoprotein GP-25in common carp juvenile by immersion

Directory of Open Access Journals (Sweden)

Soko Nuswantoro

2013-11-01

Full Text Available Koi herpesvirus (KHV is a herpesvirus that particularly infects and causes mass mortality to koi and common carp. Therefore, the protection of common carp from KHV infection is urgently needed. In this study, we developed an application of DNA vaccine encoding KHV glycoprotein-25 by immersion method to increase survival of common carp against KHV infection. A total of 400 common carp juveniles at 30-day-old were immersed in 1-L water containing 1.3×108CFU/mL of the killed Escherichia coli cells carrying DNA vaccine. Three frequencies and three duration of fish immersion were tested, namely: 1×30 minutes, 1×60 minutes, 1× 90 minutes, 2×90 minutes and 3×90 minutes by interval of 24 hours. Reversetranscription polymerase chain reaction analysis showed that DNA vaccine was successfully expressed in the vaccinated fish. Fish at twenty eight days post vaccination were challenged by injecting 10-4 mL of KHV per fish. The result showed that vaccination by 1×30 minutes immersion allowed 61% of fish survived, and this was significantly higher (p<0.05 compared to control (without vaccination, but it was similar among vaccination treatments (p>0.05. The relative percent survival of vaccinated fish were also similar among treatments (p>0.05. DNA vaccination has increased fish survival about two fold higher compared to unvaccinated fish control (26.67%. Thus, DNA vaccination was effectively delivered by immersion for 1×30 minutes, and this technique can be useful to level up the resistance of common carp juveniles against KHV infection. Keywords: DNA vaccine, KHV, glycoprotein, immersion, common carp

Cold-water immersion decreases cerebral oxygenation but improves recovery after intermittent-sprint exercise in the heat.

Science.gov (United States)

Minett, G M; Duffield, R; Billaut, F; Cannon, J; Portus, M R; Marino, F E

2014-08-01

This study examined the effects of post-exercise cooling on recovery of neuromuscular, physiological, and cerebral hemodynamic responses after intermittent-sprint exercise in the heat. Nine participants underwent three post-exercise recovery trials, including a control (CONT), mixed-method cooling (MIX), and cold-water immersion (10 °C; CWI). Voluntary force and activation were assessed simultaneously with cerebral oxygenation (near-infrared spectroscopy) pre- and post-exercise, post-intervention, and 1-h and 24-h post-exercise. Measures of heart rate, core temperature, skin temperature, muscle damage, and inflammation were also collected. Both cooling interventions reduced heart rate, core, and skin temperature post-intervention (P recovery of voluntary force by 12.7 ± 11.7% (mean ± SD) and 16.3 ± 10.5% 1-h post-exercise compared to MIX and CONT, respectively (P  0.05). CWI reduced cerebral oxygenation compared to MIX and CONT post-intervention (P recovery after post-exercise cooling appear to be disassociated with cerebral oxygenation, rather reflecting reductions in thermoregulatory demands to sustain force production. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Anticorrosive performance of waterborne epoxy coatings containing water-dispersible hexagonal boron nitride (h-BN) nanosheets

Science.gov (United States)

Cui, Mingjun; Ren, Siming; Chen, Jia; Liu, Shuan; Zhang, Guangan; Zhao, Haichao; Wang, Liping; Xue, Qunji

2017-03-01

Homogenous dispersion of hexagonal boron nitride (h-BN) nanosheets in solvents or in the polymer matrix is crucial to initiate their many applications. Here, homogeneous dispersion of hexagonal boron nitride (h-BN) in epoxy matrix was achieved with a water-soluble carboxylated aniline trimer derivative (CAT-) as a dispersant, which was attributed to the strong π-π interaction between h-BN and CAT-, as proved by Raman and UV-vis spectra. Transmission electron microscopy (TEM) analysis confirmed a random dispersion of h-BN nanosheets in the waterborne epoxy coatings. The deterioration process of water-borne epoxy coating with and without h-BN nanosheets during the long-term immersion in 3.5 wt% NaCl solution was investigated by electrochemical measurements and water absorption test. Results implied that the introduction of well dispersed h-BN nanosheets into waterborne epoxy system remarkably improved the corrosion protection performance to substrate. Moreover, 1 wt% BN/EP composite coated substrate exhibited higher impedance modulus (1.3 × 106 Ω cm2) and lower water absorption (4%) than those of pure waterborne epoxy coating coated electrode after long-term immersion in 3.5 wt% NaCl solution, demonstrating its superior anticorrosive performance. This enhanced anticorrosive performance was mainly ascribed to the improved water barrier property of epoxy coating via incorporating homogeneously dispersed h-BN nanosheets.

The emotional and cognitive effect of immersion in film viewing

NARCIS (Netherlands)

Visch, V.T.; Tan, E.S.; Molenaar, D.

2010-01-01

This brief report presents an experiment testing the effect of immersion on emotional responses and cognitive genre categorisation of film viewers. Immersion of a film presentation was varied by presenting an animated movie either in a 3D-viewing condition (low immersive condition) or in a CAVE

Comparison of hemodynamics during hyperthermal immersion and exercise testing in apparently healthy females aged 50-60 years.

Science.gov (United States)

Lietava, Jan; Vohnout, Branislav; Valent, Denis; Celko, Juraj

2004-07-01

Owing to excessive worries regarding adverse cardiac events, hyperthermal balneotherapy for patients with coronary artery disease is underprescribed. However, very few cardiac events occur in similar heat stress during Finnish sauna bathing. Exercise testing has proven to be a safe diagnostic procedure even in survivors of myocardial infarction. We compared the effects of hyperthermal immersion and exercise testing on cardiac hemodynamics in 21 apparently healthy women aged 50-60 years. The maximal symptom-limited bicycle exercise test was performed according to the modified protocol of Wasserman. Hyperthermal immersion was carried out in 40 degrees C water and was completed by increasing the core temperature by about 2 degrees C. The left ventricular function was evaluated using continuous measurement of thoracic electric bioimpedance during both tests. The blood pressure, index of contractility and heart rate were measured directly, whereas the cardiac index, left cardiac work index and systemic vascular resistance index were calculated. The hemodynamic response, as assessed at continuous non-invasive monitoring, showed substantial differences between hyperthermal immersion and exercise testing. Overall, we found a significantly lower hemodynamic load during hyperthermal immersion in comparison with exercise testing. Entering the bath, there was a significant decrease in the left cardiac work, contractility and blood pressure. We recorded a slight increase in the heart rate towards peak hyperthermal immersion. However, other modulators such as the mean arterial pressure, index of contractility, cardiac index and left cardiac work index decreased even below resting values. Excessive hyperthermal immersion induced a lower hemodynamic load in apparently healthy women than standard maximal exercise testing.

Altered Perspectives: Immersive Environments

Science.gov (United States)

Shipman, J. S.; Webley, P. W.

2016-12-01

Immersive environments provide an exciting experiential technology to visualize the natural world. Given the increasing accessibility of 360o cameras and virtual reality headsets we are now able to visualize artistic principles and scientific concepts in a fully immersive environment. The technology has become popular for photographers as well as designers, industry, educational groups, and museums. Here we show a sci-art perspective on the use of optics and light in the capture and manipulation of 360o images and video of geologic phenomena and cultural heritage sites in Alaska, England, and France. Additionally, we will generate intentionally altered perspectives to lend a surrealistic quality to the landscapes. Locations include the Catacombs of Paris, the Palace of Versailles, and the Northern Lights over Fairbanks, Alaska. Some 360o view cameras now use small portable dual lens technology extending beyond the 180o fish eye lens previously used, providing better coverage and image quality. Virtual reality headsets range in level of sophistication and cost, with the most affordable versions using smart phones and Google Cardboard viewers. The equipment used in this presentation includes a Ricoh Theta S spherical imaging camera. Here we will demonstrate the use of 360o imaging with attendees being able to be part of the immersive environment and experience our locations as if they were visiting themselves.

Immersion and contact freezing experiments in the Mainz wind tunnel laboratory

Science.gov (United States)

Eppers, Oliver; Mayer, Amelie; Diehl, Karoline; Mitra, Subir; Borrmann, Stephan; Szakáll, Miklós

2016-04-01

Immersion and contact freezing are of outmost important ice nucleation processes in mixed phase clouds. Experimental studies are carried out in the Mainz vertical wind tunnel laboratory in order to characterize these nucleation processes for different ice nucleating particles (INP), such as for mineral dust or biological particles. Immersion freezing is investigated in our laboratory with two different experimental techniques, both attaining contact-free levitation of liquid droplets and cooling of the surrounding air down to about -25 °C. In an acoustic levitator placed in the cold room of our laboratory, drops with diameters of 2 mm are investigated. In the vertical air stream of the wind tunnel droplets with diameter of 700 micron are freely floated at their terminal velocities, simulating the flow conditions of the free atmosphere. Furthermore, the wind tunnel offers a unique platform for contact freezing experiments. Supercooled water droplets are floated in the vertical air stream at their terminal velocities and INP are injected into the tunnel air stream upstream of them. As soon as INP collides with the supercooled droplet the contact freezing is initiated. The first results of immersion and contact freezing experiments with cellulose particles both in the acoustic levitator and in the wind tunnel will be presented. Cellulose is considered as typical INP of biological origin and a macrotracer for plant debris. Nucleating properties of cellulose will be provided, mainly focusing on the temperature, INP concentration, and specific surface area dependences of the freezing processes. Direct comparison between the different experimental techniques (acoustic levitator and wind tunnel), as well as between nucleation modes (immersion and contact freezing) will be presented. The work is carried out within the framework of the German research unit INUIT.

Application of neutral electrolyzed water to disinfection of alginate impression.

Science.gov (United States)

Nagamatsu, Yuki; Chen, Ker-Kong; Nagamatsu, Hiroshi; Kozono, Yoshio; Shimizu, Hiroshi

2016-01-01

Neutral electrolyzed water was developed with new concepts of long-term good durability and minimum corrosiveness to metal in addition to its excellent bactericidal activities similar to acid type of electrolyzed waters. The present study examined the bactericidal effects of the neutral electrolyzed water on disinfection of the alginate impression of a dental arch model contaminated by bacteria. Only 1-min immersion in neutral electrolyzed water could sufficiently disinfect the alginate impression including the metallic tray under ultrasonic with no significant differences from acid electrolyzed waters. No bactericidal effects were found in any electrolyzed water when used as mixing water. Considering the advantages and disadvantages of each electrolyzed water in a comprehensive way, it was suggested that neutral electrolyzed water may be the most appropriate for the disinfection of alginate impression.

Photogrammetric Applications of Immersive Video Cameras

OpenAIRE

Kwiatek, K.; Tokarczyk, R.

2014-01-01

The paper investigates immersive videography and its application in close-range photogrammetry. Immersive video involves the capture of a live-action scene that presents a 360° field of view. It is recorded simultaneously by multiple cameras or microlenses, where the principal point of each camera is offset from the rotating axis of the device. This issue causes problems when stitching together individual frames of video separated from particular cameras, however there are ways to ov...

Sensibility, Narcissism and Affect: Using Immersive Practices in Design for Embodied Experience

Directory of Open Access Journals (Sweden)

Jocelyn Spence

2018-04-01

Full Text Available ‘Embodiment’ need not focus on isolated individuals or group interactions. This article articulates the potential for designs that prompt participants to bring relationships with other people to mind. These can be fleeting relationships between participants and unknown others, or remembered relationships with romantic partners, family members, or close friends who are not physically co-present or digitally represented. In either case, it is possible to generate affective responses that profoundly shape participants’ emotional and physical reactions to, and co-creation of, the designed interaction. This article presents existing practices of immersive theatre to frame our exploration of this phenomenon. It introduces three theories—mise-en-sensibilité, narcissistic spectatorship and affect—through which we illuminate both the internally felt and the externally designed experience, whether or not it is explicitly framed as theatrical performance. Through analysis of two immersive performances (one-on-one interactions that could easily be understood in terms of experience design and two designs of our own, we argue that the affect generated by personal relationships in immersive experiences can both shape and drive participation, and we offer a three-point guideline by which one can design for the affective consequences of bringing relationships to mind.

Progress in video immersion using Panospheric imaging

Science.gov (United States)

Bogner, Stephen L.; Southwell, David T.; Penzes, Steven G.; Brosinsky, Chris A.; Anderson, Ron; Hanna, Doug M.

1998-09-01

Having demonstrated significant technical and marketplace advantages over other modalities for video immersion, PanosphericTM Imaging (PI) continues to evolve rapidly. This paper reports on progress achieved since AeroSense 97. The first practical field deployment of the technology occurred in June-August 1997 during the NASA-CMU 'Atacama Desert Trek' activity, where the Nomad mobile robot was teleoperated via immersive PanosphericTM imagery from a distance of several thousand kilometers. Research using teleoperated vehicles at DRES has also verified the exceptional utility of the PI technology for achieving high levels of situational awareness, operator confidence, and mission effectiveness. Important performance enhancements have been achieved with the completion of the 4th Generation PI DSP-based array processor system. The system is now able to provide dynamic full video-rate generation of spatial and computational transformations, resulting in a programmable and fully interactive immersive video telepresence. A new multi- CCD camera architecture has been created to exploit the bandwidth of this processor, yielding a well-matched PI system with greatly improved resolution. While the initial commercial application for this technology is expected to be video tele- conferencing, it also appears to have excellent potential for application in the 'Immersive Cockpit' concept. Additional progress is reported in the areas of Long Wave Infrared PI Imaging, Stereo PI concepts, PI based Video-Servoing concepts, PI based Video Navigation concepts, and Foveation concepts (to merge localized high-resolution views with immersive views).

Immersive virtual reality simulations in nursing education.

Science.gov (United States)

Kilmon, Carol A; Brown, Leonard; Ghosh, Sumit; Mikitiuk, Artur

2010-01-01

This article explores immersive virtual reality as a potential educational strategy for nursing education and describes an immersive learning experience now being developed for nurses. This pioneering project is a virtual reality application targeting speed and accuracy of nurse response in emergency situations requiring cardiopulmonary resuscitation. Other potential uses and implications for the development of virtual reality learning programs are discussed.

Aberration characteristics of immersion lenses for LVSEM

International Nuclear Information System (INIS)

Khursheed, Anjam

2002-01-01

This paper investigates the on-axis aberration characteristics of various immersion objective lenses for low voltage scanning electron microscopy (LVSEM). A simple aperture lens model is used to generate smooth axial field distributions. The simulation results show that mixed field electric-magnetic immersion lenses are predicted to have between 1.5 and 2 times smaller aberration limited probe diameters than their pure-field counterparts. At a landing energy of 1 keV, mixed field immersion lenses operating at the vacuum electrical field breakdown limit are predicted to have on-axis aberration coefficients between 50 and 60 μm, yielding an ultimate image resolution of below 1 nm. These aberrations lie in the same range as those for LVSEM systems that employ aberration correctors

Hybrid finite difference/finite element immersed boundary method.

Science.gov (United States)

E Griffith, Boyce; Luo, Xiaoyu

2017-12-01

The immersed boundary method is an approach to fluid-structure interaction that uses a Lagrangian description of the structural deformations, stresses, and forces along with an Eulerian description of the momentum, viscosity, and incompressibility of the fluid-structure system. The original immersed boundary methods described immersed elastic structures using systems of flexible fibers, and even now, most immersed boundary methods still require Lagrangian meshes that are finer than the Eulerian grid. This work introduces a coupling scheme for the immersed boundary method to link the Lagrangian and Eulerian variables that facilitates independent spatial discretizations for the structure and background grid. This approach uses a finite element discretization of the structure while retaining a finite difference scheme for the Eulerian variables. We apply this method to benchmark problems involving elastic, rigid, and actively contracting structures, including an idealized model of the left ventricle of the heart. Our tests include cases in which, for a fixed Eulerian grid spacing, coarser Lagrangian structural meshes yield discretization errors that are as much as several orders of magnitude smaller than errors obtained using finer structural meshes. The Lagrangian-Eulerian coupling approach developed in this work enables the effective use of these coarse structural meshes with the immersed boundary method. This work also contrasts two different weak forms of the equations, one of which is demonstrated to be more effective for the coarse structural discretizations facilitated by our coupling approach. © 2017 The Authors International  Journal  for  Numerical  Methods  in  Biomedical  Engineering Published by John Wiley & Sons Ltd.

$f$-Biminimal immersions

OpenAIRE

GÜRLER, FATMA; ÖZGÜR, CİHAN

2017-01-01

In the present paper, we define $f$-biminimal immersions. We consider $f$-biminimal curves in a Riemannian manifold and $f$-biminimal submanifolds of codimension $1$ in a Riemannian manifold, and we give examples of $f$-biminimal surfaces. Finally, we consider $f$-biminimal Legendre curves in Sasakian space forms and give an example.

Immersible solar heater for fluids

Science.gov (United States)

Kronberg, James W.

1995-01-01

An immersible solar heater comprising a light-absorbing panel attached to a frame for absorbing heat energy from the light and transferring the absorbed heat energy directly to the fluid in which the heater is immersed. The heater can be used to heat a swimming pool, for example, and is held in position and at a preselected angle by a system of floats, weights and tethers so that the panel can operate efficiently. A skid can be used in one embodiment to prevent lateral movement of the heater along the bottom of the pool. Alternative embodiments include different arrangements of the weights, floats and tethers and methods for making the heater.

A common path forward for the immersive visualization community

Energy Technology Data Exchange (ETDEWEB)

Eric A. Wernert; William R. Sherman; Patrick O' Leary; Eric Whiting

2012-03-01

Immersive visualization makes use of the medium of virtual reality (VR) - it is a subset of virtual reality focused on the application of VR technologies to scientific and information visualization. As the name implies, there is a particular focus on the physically immersive aspect of VR that more fully engages the perceptual and kinesthetic capabilities of the scientist with the goal of producing greater insight. The immersive visualization community is uniquely positioned to address the analysis needs of the wide spectrum of domain scientists who are becoming increasingly overwhelmed by data. The outputs of computational science simulations and high-resolution sensors are creating a data deluge. Data is coming in faster than it can be analyzed, and there are countless opportunities for discovery that are missed as the data speeds by. By more fully utilizing the scientists visual and other sensory systems, and by offering a more natural user interface with which to interact with computer-generated representations, immersive visualization offers great promise in taming this data torrent. However, increasing the adoption of immersive visualization in scientific research communities can only happen by simultaneously lowering the engagement threshold while raising the measurable benefits of adoption. Scientists time spent immersed with their data will thus be rewarded with higher productivity, deeper insight, and improved creativity. Immersive visualization ties together technologies and methodologies from a variety of related but frequently disjoint areas, including hardware, software and human-computer interaction (HCI) disciplines. In many ways, hardware is a solved problem. There are well established technologies including large walk-in systems such as the CAVE{trademark} and head-based systems such as the Wide-5{trademark}. The advent of new consumer-level technologies now enable an entirely new generation of immersive displays, with smaller footprints and costs

Immersed boundary-simplified lattice Boltzmann method for incompressible viscous flows

Science.gov (United States)

Chen, Z.; Shu, C.; Tan, D.

2018-05-01

An immersed boundary-simplified lattice Boltzmann method is developed in this paper for simulations of two-dimensional incompressible viscous flows with immersed objects. Assisted by the fractional step technique, the problem is resolved in a predictor-corrector scheme. The predictor step solves the flow field without considering immersed objects, and the corrector step imposes the effect of immersed boundaries on the velocity field. Different from the previous immersed boundary-lattice Boltzmann method which adopts the standard lattice Boltzmann method (LBM) as the flow solver in the predictor step, a recently developed simplified lattice Boltzmann method (SLBM) is applied in the present method to evaluate intermediate flow variables. Compared to the standard LBM, SLBM requires lower virtual memories, facilitates the implementation of physical boundary conditions, and shows better numerical stability. The boundary condition-enforced immersed boundary method, which accurately ensures no-slip boundary conditions, is implemented as the boundary solver in the corrector step. Four typical numerical examples are presented to demonstrate the stability, the flexibility, and the accuracy of the present method.

Experience dans une classe d'immersion francaise aux Milles-Iles (An Experience in a French Immersion Class in Mille-Iles)

Science.gov (United States)

Pariseau, Cecile

1978-01-01

A description of an immersion program for 6-year-old anglophone children modeled on "les classes d'accueil" for immigrant children. The program of intensive instruction in oral and written French is outlined. This school district has found this type of immersion superior to the usual kind. (The text is in French.) (AMH)

Enabling immersive simulation.

Energy Technology Data Exchange (ETDEWEB)

McCoy, Josh (University of California Santa Cruz, Santa Cruz, CA); Mateas, Michael (University of California Santa Cruz, Santa Cruz, CA); Hart, Derek H.; Whetzel, Jonathan; Basilico, Justin Derrick; Glickman, Matthew R.; Abbott, Robert G.

2009-02-01

The object of the 'Enabling Immersive Simulation for Complex Systems Analysis and Training' LDRD has been to research, design, and engineer a capability to develop simulations which (1) provide a rich, immersive interface for participation by real humans (exploiting existing high-performance game-engine technology wherever possible), and (2) can leverage Sandia's substantial investment in high-fidelity physical and cognitive models implemented in the Umbra simulation framework. We report here on these efforts. First, we describe the integration of Sandia's Umbra modular simulation framework with the open-source Delta3D game engine. Next, we report on Umbra's integration with Sandia's Cognitive Foundry, specifically to provide for learning behaviors for 'virtual teammates' directly from observed human behavior. Finally, we describe the integration of Delta3D with the ABL behavior engine, and report on research into establishing the theoretical framework that will be required to make use of tools like ABL to scale up to increasingly rich and realistic virtual characters.

Animal imaging using immersion

Science.gov (United States)

Kalogerakis, Konstantinos S.; Kotz, Kenneth T.; Rand, Kendra; Faris, Gregory W.

2003-07-01

We are using rodent animal models to study and compare contrast mechanisms for detection of breast cancer. These measurements are performed with the animals immersed in a matching scattering medium. The matching scattering medium or liquid tissue phantom comprises a mixture of Ropaque (hollow acrylic/styrene microspheres) and ink. We have previously applied matched imaging to imaging in humans. Surrounding the imaged region with a matched tissue phantom compensates for variations in tissue thickness and geometry, provides more uniform illumination, and allows better use of the dynamic range of the imaging system. If the match is good, the boundaries of the imaged region should almost vanish, enhancing the contrast from internal structure as compared to contrast from the boundaries and surface topography. For our measurements in animals, the immersion plays two additional roles. First, we can readily study tumors through tissue thickness similar to that of a human breast. Although the heterogeneity of the breast is lost, this is a practical method to study the detection of small tumors and monitor changes as they grow. Second, the immersion enhances our ability to quantify the contrast mechanisms for peripheral tumors on the animal because the boundary effects on photon migration are eliminated. We are currently developing two systems for these measurements. One is a continuous-wave (CW) system based on near-infrared LED illumination and a CCD (charge-coupled device) camera. The second system, a frequency domain system, can help quantify the changes observed with the CW system.

Immersion Suit Usage Within the RAAF

Science.gov (United States)

1992-01-01

IMMERSION SUIT USED UVIC QDIS HOLDINGS 202. in 12 Sizes, held by ALSS 492SQN REQUIREMENTS No comment USAGE POLICY REFERENCE DIRAF) AAP 7215.004-1 (P3C...held by ALSS 492SQN. REQUIREMENTS No comment ISACE POLICY REFERENCE DIIAF) AAP 7215.004-1 (P3C Flight Manual) RAAF Supplement No 92 USAGE POUICY UVIC...TYPE P3C REFERENCE Telecon FLTLT Toft I I SQNfRESO AVMED Dated 22 Mar 91 IMMERSION SUIT USED UVIC QDIS HOLDINGS No comment REQUIREMENTS No comment USAGE

Ultrasonic and immersion cleaning: a comparison using aqueous and fluorocarbon solvents

International Nuclear Information System (INIS)

Bond, R.D.; Kearsey, A.

1984-11-01

Decontamination is a necessary process in reducing radiation levels in the working environment in the nuclear industry. Components from active areas which require decontamination for re-use or maintenance operations. In this report, a typical chemical cleaning process using liquid pumping, airagitation and physical movement for agitation is compared with ultrasonic cleaning, now an established cleaning process in many industries. The chosen traditional method is immersion in an agitated solution of warm SDG.3 solution; an established decontaminating reagent. The decontamination effect of this process is compared with the effect of cleaning in an ultrasonic bath containing the same reagent at the same concentration and temperature. Fluorocarbon reagents are of particular interest to the nuclear industry for they offer the ability to clean electrical components without damage, and can clean product contaminated material without the risk of criticality. Such reagents are based on 1,1,2-trichloro, 1,2,2-trifluoroethane and azeotropic mixtures. This reagent and one mixture with 6% methanol were tested under agitation and ultrasonic immersion at the same temperature. Parallel control experiments were conducted using demineralised water as the cleaning media in an agitated bath. SGG3 is a good reagent for general purpose cleaning (it can remove 99% of particulate contamination) using scrubbing, immersion or spraying techniques. There is little evidence to show that ultrasonic cleaning increases its effectiveness. For special purpose fluorocarbon solvents will give satisfactory results when used in an ultrasonic system. (author)

Long-Term Persistency of Abnormal Heart Rate Variability following Long NICU Stay and Surgery at Birth

Directory of Open Access Journals (Sweden)

Mélanie Morin

2014-01-01

Full Text Available Preterm birth is associated with painful procedures during the neonatal intensive care unit (NICU stay. Full-term newborns can also experience pain, following surgery. These procedures can have long-lasting consequences. It has been shown that children born preterm show pain responses and cardiac alterations. This study aimed to explore the heart rate reactivity to pain in 107 subjects born either preterm or full-term who were between 7 and 25 years old at testing. We also evaluated the effect of pain experienced at birth, as represented by a longer NICU stay, time under ventilation, and surgery at birth. Participants were asked to immerse their right forearm in 10°C water for 2 minutes. Electrocardiograms were recorded at baseline and during the immersion procedure. Full-term subjects showed a stable increase in heart rate throughout the procedure, whereas preterm ones showed a strong increase at the beginning, which decreased over time. Also, preterm and full-term subjects who experienced pain at birth showed higher resting heart rate, stronger sympathetic activity, and lower cardiac vagal activity. Our study demonstrated a long-term impact of a long NICU stay and surgery at birth on cardiac autonomic activity. This could lead to impaired reactions to pain or stress in later life.

Construction of codimension 1 immersions of spacetime: the exceptional case

International Nuclear Information System (INIS)

Edelen, Dominic G B

2005-01-01

The Frobenius theorem was used in Edelen (2003 Class. Quantum Grav. 20 3661) to obtain a general body of results for the immersion of spacetime in flat spaces of higher dimension. This addendum completes those results for the exceptional case of immersions of codimension 1 where the Frobenius theorem need not be applied. Local actions of the Poincare groups SO(2, 3)--T(5) or SO(1, 4) -- T(5) are used to obtain immersions of spacetime of codimension 1 that involve six arbitrary functions of the four immersion parameters and an arbitrary constant. Explicit calculations are given for several cases. (addendum)

Prospective multicenter randomized controlled trial comparing adenoma detection rate in colonoscopy using water exchange, water immersion, and air insufflation.

Science.gov (United States)

Hsieh, Yu-Hsi; Tseng, Chih-Wei; Hu, Chi-Tan; Koo, Malcolm; Leung, Felix W

2017-07-01

Adenoma detection rate (ADR), defined as the proportion of patients with at least one adenoma of any size, is a quality indicator. We tested the hypothesis that water exchange (WE) improves ADR but water immersion (WI) has no adverse effect on ADR compared with air insufflation (AI). A prospective study was conducted at the Dalin Tzu Chi Hospital in southern Taiwan and the Hualien Tzu Chi Hospital in eastern Taiwan on patients randomly assigned to WE, WI, or AI with stratification by the 3 study colonoscopists. The primary outcome was ADR. From July 2013 to December 2015, 651 patients were recruited and randomized into 3 groups with a 1:1:1 ratio (217 patients per group). Overall, ADR met quality standards: WE 49.8% (95% CI, 43.2%-56.4%), AI 37.8% (95% CI, 31.6%-44.4%), and WI 40.6% (95% CI, 34.2%-47.2%). Compared with AI, WE significantly increased ADR (P = .016). There was no difference between WI and WE. ADRs of WI and AI were comparable. Compared with AI, WE confirmed a longer insertion time, higher cleanliness score, but similar adenoma per positive colonoscopy (APPC) and withdrawal time with polypectomy. Subgroup analysis found WE significantly increased ADR in propofol-sedated patients. Multivariate generalized linear mixed model analysis revealed that age ≥50 years, WE (vs AI), colonoscopy indication, no previous history of colonoscopy, and withdrawal time >8 minutes were significant predictors of increased ADR. Confirmation of prior reports showing WE, but not WI, increased ADR further strengthened the validity of our observations. WE significantly increased ADR in propofol-sedated patients. The outcome differences justify assessment of the role of WE in colorectal cancer prevention. Similar APPC and withdrawal times suggest that adequate inspection was performed on colonoscope withdrawal in each of the study arms. (Clinical trial registration number: NCT01894191.). Copyright © 2017 American Society for Gastrointestinal Endoscopy. All rights reserved.

Color stability of ceramic brackets immersed in potentially staining solutions.

Science.gov (United States)

Guignone, Bruna Coser; Silva, Ludimila Karsbergen; Soares, Rodrigo Villamarim; Akaki, Emilio; Goiato, Marcelo Coelho; Pithon, Matheus Melo; Oliveira, Dauro Douglas

2015-01-01

To assess the color stability of five types of ceramic brackets after immersion in potentially staining solutions. Ninety brackets were divided into 5 groups (n = 18) according to brackets commercial brands and the solutions in which they were immersed (coffee, red wine, coke and artificial saliva). The brackets assessed were Transcend (3M/Unitek, Monrovia, CA, USA), Radiance (American Orthodontics, Sheboygan, WI, USA), Mystique (GAC International Inc., Bohemia, NY, USA) and Luxi II (Rocky Mountain Orthodontics, Denver, CO, USA). Chromatic changes were analyzed with the aid of a reflectance spectrophotometer and by visual inspection at five specific time intervals. Assessment periods were as received from the manufacturer (T0), 24 hours (T1), 72 hours (T2), as well as 7 days (T3) and 14 days (T4) of immersion in the aforementioned solutions. Results were submitted to statistical analysis with ANOVA and Bonferroni correction, as well as to a multivariate profile analysis for independent and paired samples with significance level set at 5%. The duration of the immersion period influenced color alteration of all tested brackets, even though these changes could not always be visually observed. Different behaviors were observed for each immersion solution; however, brackets immersed in one solution progressed similarly despite minor variations. Staining became more intense over time and all brackets underwent color alterations when immersed in the aforementioned solutions.

In-situ Non-Invasive Imaging of Liquid-Immersed Thin Film Composite Membranes

KAUST Repository

Ogieglo, Wojciech

2017-10-14

We present a non-invasive method to directly image liquid-immersed thin film composite membranes. The approach allows accessing information not only on the lateral distribution of the coating thickness, including variations in its swelling and density, but also on the distribution of substrate porosity, roughness, accessibility of pores to liquid, and even the degree of pore intrusion related to the thin layer deposition process. The method can be particularly helpful in the fields of functional coatings or membranes to allow laterally-resolved studies under realistic application conditions thereby opening completely new research avenues. The approach is demonstrated in a study of two polymers of intrinsic microporosity, PIM-1 and PIM-6FDA-OH, coated on polyacrylonitrile support and immersed in water. Variations of the skin morphology using different coating methods (floating, spin-coating and dip-coating) are evaluated with the help of the presented method. Surfaces of at least tens of cm2 can be potentially analyzed.

Immersive Virtual Reality with Applications to Tele-Operation and Training

Science.gov (United States)

2016-03-07

reviewed journals : Number of Papers published in non peer-reviewed journals : Final Report: Immersive Virtual Reality with Applications to Tele-Operation... Immersive Virtual Reality with Applications to Tele-Operation and Training The proposed project aims to develop a fundamental framework for...establishing an immersive virtual reality environment for robust and scalable human robotics interaction in a cooperative intelligent architecture at the

Comparative study on collaborative interaction in non-immersive and immersive systems

Science.gov (United States)

Shahab, Qonita M.; Kwon, Yong-Moo; Ko, Heedong; Mayangsari, Maria N.; Yamasaki, Shoko; Nishino, Hiroaki

2007-09-01

This research studies the Virtual Reality simulation for collaborative interaction so that different people from different places can interact with one object concurrently. Our focus is the real-time handling of inputs from multiple users, where object's behavior is determined by the combination of the multiple inputs. Issues addressed in this research are: 1) The effects of using haptics on a collaborative interaction, 2) The possibilities of collaboration between users from different environments. We conducted user tests on our system in several cases: 1) Comparison between non-haptics and haptics collaborative interaction over LAN, 2) Comparison between non-haptics and haptics collaborative interaction over Internet, and 3) Analysis of collaborative interaction between non-immersive and immersive display environments. The case studies are the interaction of users in two cases: collaborative authoring of a 3D model by two users, and collaborative haptic interaction by multiple users. In Virtual Dollhouse, users can observe physics law while constructing a dollhouse using existing building blocks, under gravity effects. In Virtual Stretcher, multiple users can collaborate on moving a stretcher together while feeling each other's haptic motions.

Through-flow cell of immersion sensor

International Nuclear Information System (INIS)

Svandelik, J.

1986-01-01

The cell consists of a jacket in shape of a triangular pyramid whose two opposite and skew edges are truncated. It is provided with inlet and outlet openings. The measuring immersion sensor is inserted through the outlet opening or through an opening provided in one of the jacket side walls. The immersion sensor cell is mainly used for in-service inspection of radioactivity of the ion exchanger at the output of the elution column in the manufacture of chemical concentrates of uranium from ores. (J.B.). 4 figs

3D immersive patient simulators and their impact on learning success: a thematic review.

Science.gov (United States)

Kleinert, Robert; Wahba, Roger; Chang, De-Hua; Plum, Patrick; Hölscher, Arnulf H; Stippel, Dirk L

2015-04-08

Immersive patient simulators (IPSs) combine the simulation of virtual patients with a three-dimensional (3D) environment and, thus, allow an illusionary immersion into a synthetic world, similar to computer games. Playful learning in a 3D environment is motivating and allows repetitive training and internalization of medical workflows (ie, procedural knowledge) without compromising real patients. The impact of this innovative educational concept on learning success requires review of feasibility and validity. It was the aim of this paper to conduct a survey of all immersive patient simulators currently available. In addition, we address the question of whether the use of these simulators has an impact on knowledge gain by summarizing the existing validation studies. A systematic literature search via PubMed was performed using predefined inclusion criteria (ie, virtual worlds, focus on education of medical students, validation testing) to identify all available simulators. Validation testing was defined as the primary end point. There are currently 13 immersive patient simulators available. Of these, 9 are Web-based simulators and represent feasibility studies. None of these simulators are used routinely for student education. The workstation-based simulators are commercially driven and show a higher quality in terms of graphical quality and/or data content. Out of the studies, 1 showed a positive correlation between simulated content and real content (ie, content validity). There was a positive correlation between the outcome of simulator training and alternative training methods (ie, concordance validity), and a positive coherence between measured outcome and future professional attitude and performance (ie, predictive validity). IPSs can promote learning and consolidation of procedural knowledge. The use of immersive patient simulators is still marginal, and technical and educational approaches are heterogeneous. Academic-driven IPSs could possibly enhance the

A Cultural Immersion Field Experience: Examining Pre-Service Music Teachers' Beliefs about Cultural Differences

Science.gov (United States)

VanDeusen, Andrea J.

2017-01-01

With the intent of informing music teacher education practices and developing more culturally responsive and relevant teachers, the purpose of this research was to explore pre-service music teachers' understandings of culture and diversity, and to examine the impact of a short-term cultural immersion field experience on pre-service music teachers'…

Isometric immersions and embeddings of locally Euclidean metrics in R2

International Nuclear Information System (INIS)

Sabitov, I Kh

1999-01-01

This paper deals with the problem of isometric immersions and embeddings of two-dimensional locally Euclidean metrics in the Euclidean plane. We find explicit formulae for the immersions of metrics defined on a simply connected domain and a number of sufficient conditions for the existence of isometric embeddings. In the case when the domain is multiply connected we find necessary conditions for the existence of isometric immersions and classify the cases when the metric admits no isometric immersion in the Euclidean plane

Assessment of Ions released from Three Types of Orthodontic Brackets immersed in Different Mouthwashes: An in vitro Study.

Science.gov (United States)

Nahidh, Mohammed; Garma, Noor Mh; Jasim, Esraa S

2018-01-01

Herbs are used widely in medicine. The purpose of the present study was to assess the ion release from gold-plated orthodontic bracket compared with other stainless steel brackets, and based on the findings of the study, the orthodontists can choose the most biocompatible brackets and mouthwashes useful in the clinical practice. A total of 150 orthodontic brackets from Orthotechnology™ Company, USA (50 stainless steel one-piece brackets, 50 stainless steel two-piece brackets, and 50 gold brackets) were immersed in four mouthwashes in addition to distilled water. Ten of each type of brackets in every media were immersed under 37°C for 45 days. Ions released in these mouthwashes were measured, and comparisons among different bracket types and among various mouthwashes were done by one-way analysis of variance (ANOVA) and then with Games-Howell tests. Increased amounts of ions released in herbal mouth-washes were recorded in gold and two-piece brackets in comparison with one-piece stainless steel brackets. Herbal mouthwashes must be used with caution as they showed an increased amount of ions released in comparison with chlorhexidine. One-piece stainless steel bracket system is the most compatible bracket type, as they released the least amount of ions. One-piece stainless steel brackets are better than two-piece brackets in terms of ions released.

Declarative Knowledge Acquisition in Immersive Virtual Learning Environments

Science.gov (United States)

Webster, Rustin

2016-01-01

The author investigated the interaction effect of immersive virtual reality (VR) in the classroom. The objective of the project was to develop and provide a low-cost, scalable, and portable VR system containing purposely designed and developed immersive virtual learning environments for the US Army. The purpose of the mixed design experiment was…

Immersion enthalpies of activated carbon cloths as physical chemistry characterization parameter

International Nuclear Information System (INIS)

Rodriguez, Giovanny; Giraldo, Liliana; Moreno Juan Carlos

2009-01-01

The immersion enthalpies of five activated carbon cloths in carbon, CCl 4 , H 2 O and NaOH and HCl 0.1 M solutions are determined. The surface area values of the cloths are between 243 and 848 m 2 g-1 and exhibit a linear relationship with the immersion enthalpies in CCl 4 . The immersion enthalpies of carbon cloths are between 5.49 and 42.3 Jg-1 for CCl 4 and 3.83 and 7.54 Jg-1 for H 2 O. The immersion enthalpies in the solutions are related to the contents of acidic and basic groups and find that in the first case to increase the immersion enthalpy in NaOH increases the total acidity. Hydrophobic factor is calculated from the immersion enthalpies in CCl 4 and H 2 O, that indicate the interaction with polar and a polar compounds, and also relates to pHPZC each sample.

Color stability of ceramic brackets immersed in potentially staining solutions

Directory of Open Access Journals (Sweden)

Bruna Coser Guignone

2015-08-01

Full Text Available OBJECTIVE: To assess the color stability of five types of ceramic brackets after immersion in potentially staining solutions.METHODS: Ninety brackets were divided into 5 groups (n = 18 according to brackets commercial brands and the solutions in which they were immersed (coffee, red wine, coke and artificial saliva. The brackets assessed were Transcend (3M/Unitek, Monrovia, CA, USA, Radiance (American Orthodontics, Sheboygan, WI, USA, Mystique (GAC International Inc., Bohemia, NY, USA and Luxi II (Rocky Mountain Orthodontics, Denver, CO, USA. Chromatic changes were analyzed with the aid of a reflectance spectrophotometer and by visual inspection at five specific time intervals. Assessment periods were as received from the manufacturer (T0, 24 hours (T1, 72 hours (T2, as well as 7 days (T3 and 14 days (T4 of immersion in the aforementioned solutions. Results were submitted to statistical analysis with ANOVA and Bonferroni correction, as well as to a multivariate profile analysis for independent and paired samples with significance level set at 5%.RESULTS: The duration of the immersion period influenced color alteration of all tested brackets, even though these changes could not always be visually observed. Different behaviors were observed for each immersion solution; however, brackets immersed in one solution progressed similarly despite minor variations.CONCLUSIONS: Staining became more intense over time and all brackets underwent color alterations when immersed in the aforementioned solutions.

A Conceptual Framework of Immersive Shared Environments Emphasizing Social Interaction

Directory of Open Access Journals (Sweden)

Mi Jeong Kim

2015-11-01

Full Text Available The effectiveness of visual displays has often been linked to the sense of presence embodied by immersive visualization. However, efforts analyzing how presence is associated with multi-users’ quality of communication, including visualization capabilities to assist in architecture, engineering and construction (AEC, are still unfolding. This research is an exploratory study on social interaction, which aims to improve the presentation and communication of complex data through immersive simulation techniques. This paper reviews key concepts such as presence and immersion to identify factors that influence communication in the representative literature. It then introduces the Hub for Immersive Visualization and eResearch (HIVE with a focus on the technological components. Finally it presents a conceptual framework of immersive shared environment, which enables multi-users to understand how to implement social interaction in a system efficiently or to determine whether a visualization system could support communication effectively. Future studies to validate the proposed framework are discussed, particularly in the context of cognitive factors in a shared environment.

Adoption of the Creative Process According to the Immersive Method

Directory of Open Access Journals (Sweden)

Sonja Vuk

2015-09-01

Full Text Available The immersive method is a new concept of visual education that is better suited to the needs of students in contemporary post-industrial society. The features of the immersive method are: 1 it emerges from interaction with visual culture; 2 it encourages understanding of contemporary art (as an integral part of visual culture; and 3 it implements the strategies and processes of the dominant tendencies in contemporary art (new media art and relational art with the goal of adopting the creative process, expressing one’s thoughts and emotions, and communicating with the environment. The immersive method transfers the creative process from art to the process of creation by the students themselves. This occurs with the mediation of an algorithmic scheme that enables students to adopt ways to solve problems, to express thoughts and emotions, to develop ideas and to transfer these ideas to form, medium and material. The immersive method uses transfer in classes, the therapeutic aspect of art and “flow state” (the optimal experience of being immersed in an activity/aesthetic experience (a total experience that has a beginning, a process and a conclusion/immersive experience (comprehensive immersion in the present moment. This is a state leading to the sublimative effect of creation (identification with what has been expressed, as well as to self-actualisation. The immersive method teaches one to connect the context, social relations and the artwork as a whole in which one lives as an individual. The adopted creative process is implemented in a critical manner on one’s surrounding through analysis, aesthetic interventions, and ecologically and socially aware inclusion in the life of a community. The students gain the crucial meta-competence of a creative thinking process.

Predição da força de reação do solo durante a corrida na água Prediction of ground reaction force during water immersion running

Directory of Open Access Journals (Sweden)

Alessandro Haupenthal

2010-09-01

Full Text Available Este estudo visou desenvolver um modelo para a predição da força de reação do solo na corrida subaquática. Participaram 20 sujeitos (9 homens e 11 mulheres, que realizaram corrida subaquática em dois níveis de imersão e três velocidades. Para cada sujeito foram coletadas seis passagens válidas em cada condição, com a utilização de uma plataforma subaquática de força. O modelo para predição da força foi construído por regressão linear múltipla. Foram consideradas variáveis dependentes a componente vertical e a componente ântero-posterior da força de reação do solo. As variáveis imersão, sexo, velocidade, massa corporal, densidade corporal e percentual de gordura foram consideradas independentes. Permaneceu no modelo final de regressão para a componente vertical a velocidade (pThis study aimed at developing a model to predict ground reaction force during deep-water running. A total of 20 subjects ((9 men, 11 women ran in water at two immersion levels and three different speeds. Each subject performed six valid trials in each condition, data being captured by an underwater force plate. The force prediction model was build by multiple linear regression. Dependent variables were the vertical and anteroposterior components of the ground reaction force; independent variables were runners' immersion, sex, speed, body mass, body density, and percentage of fat. At the final regression model for the vertical component, only speed remained (p<0.001, while for the anteroposterior component, speed, immersion, and body mass were maintained (all at p<0.001. The obtained model for the anteroposterior component of ground reaction force may be found satisfactory, as adjusted determination coefficient was 0.79. However, the prediction model for the vertical component cannot be recommended for prediction during deep-water running, since that coefficient was 0.18. It must be noted that the proposed prediction model applies to subjects

Population pharmacokinetics of enrofloxacin in purple sea stars (Pisaster ochraceus) following an intracoelomic injection or extended immersion.

Science.gov (United States)

Rosenberg, Justin F; Haulena, Martin; Phillips, Brianne E; Harms, Craig A; Lewbart, Gregory A; Lahner, Lesanna L; Papich, Mark G

2016-11-01

OBJECTIVE To determine population pharmacokinetics of enrofloxacin in purple sea stars (Pisaster ochraceus) administered an intracoelomic injection of enrofloxacin (5 mg/kg) or immersed in an enrofloxacin solution (5 mg/L) for 6 hours. ANIMALS 28 sea stars of undetermined age and sex. PROCEDURES The study had 2 phases. Twelve sea stars received an intracoelomic injection of enrofloxacin (5 mg/kg) or were immersed in an enrofloxacin solution (5 mg/L) for 6 hours during the injection and immersion phases, respectively. Two untreated sea stars were housed with the treated animals following enrofloxacin administration during both phases. Water vascular system fluid samples were collected from 4 sea stars and all controls at predetermined times during and after enrofloxacin administration. The enrofloxacin concentration in those samples was determined by high-performance liquid chromatography. For each phase, noncompartmental analysis of naïve averaged pooled samples was used to obtain initial parameter estimates; then, population pharmacokinetic analysis was performed that accounted for the sparse sampling technique used. RESULTS Injection phase data were best fit with a 2-compartment model; elimination half-life, peak concentration, area under the curve, and volume of distribution were 42.8 hours, 18.9 μg/mL, 353.8 μg•h/mL, and 0.25 L/kg, respectively. Immersion phase data were best fit with a 1-compartment model; elimination half-life, peak concentration, and area under the curve were 56 hours, 36.3 μg•h/mL, and 0.39 μg/mL, respectively. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that the described enrofloxacin administration resulted in water vascular system fluid drug concentrations expected to exceed the minimum inhibitory concentration for many bacterial pathogens.

Helicon plasma with additional immersed antenna

International Nuclear Information System (INIS)

Aanesland, A; Charles, C; Boswell, R W; Fredriksen, A

2004-01-01

A 'primary' RF power (H-power) at 13.56 MHz is coupled to a plasma source excited by an external double saddle field Helicon antenna. A 'secondary' RF power (S-power), also at 13.56 MHz but with variable phase, is additionally coupled by inserting a second antenna in contact with the plasma through one end of the source. The immersed antenna can be grounded or floating, allowing a self-bias to form in the latter case. Changes in the plasma density and electron temperature are measured in both cases with varying power on the immersed antenna. The plasma potential increases dramatically with S-power in the grounded case, and is found to be similar in size to the sum of the plasma potential and the self-bias formed in the floating case for all powers. Hence, the sheath between the immersed antenna and the plasma is shown to be equal in both the grounded and floating cases. Although the power efficiency does not vary significantly as a function of the S-power, it is consistently lower for the grounded case possibly as a result of a dc current to ground. The plasma parameters are drastically changed as the phase between the two antennae are varied (floating case), and a sinusoidal function was fitted to the plasma parameters as a function of the phase shift. The calculated power loss to the antenna indicates that the power efficiency of the immersed antenna, as the phase is changed, is altered from 80% to 10%

Simulation Exploration through Immersive Parallel Planes

Energy Technology Data Exchange (ETDEWEB)

Brunhart-Lupo, Nicholas J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Bush, Brian W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Gruchalla, Kenny M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Smith, Steve [Los Alamos Visualization Associates

2017-05-25

We present a visualization-driven simulation system that tightly couples systems dynamics simulations with an immersive virtual environment to allow analysts to rapidly develop and test hypotheses in a high-dimensional parameter space. To accomplish this, we generalize the two-dimensional parallel-coordinates statistical graphic as an immersive 'parallel-planes' visualization for multivariate time series emitted by simulations running in parallel with the visualization. In contrast to traditional parallel coordinate's mapping the multivariate dimensions onto coordinate axes represented by a series of parallel lines, we map pairs of the multivariate dimensions onto a series of parallel rectangles. As in the case of parallel coordinates, each individual observation in the dataset is mapped to a polyline whose vertices coincide with its coordinate values. Regions of the rectangles can be 'brushed' to highlight and select observations of interest: a 'slider' control allows the user to filter the observations by their time coordinate. In an immersive virtual environment, users interact with the parallel planes using a joystick that can select regions on the planes, manipulate selection, and filter time. The brushing and selection actions are used to both explore existing data as well as to launch additional simulations corresponding to the visually selected portions of the input parameter space. As soon as the new simulations complete, their resulting observations are displayed in the virtual environment. This tight feedback loop between simulation and immersive analytics accelerates users' realization of insights about the simulation and its output.

Beneficial effects of a novel shark-skin collagen dressing for the promotion of seawater immersion wound healing.

Science.gov (United States)

Shen, Xian-Rong; Chen, Xiu-Li; Xie, Hai-Xia; He, Ying; Chen, Wei; Luo, Qun; Yuan, Wei-Hong; Tang, Xue; Hou, Deng-Yong; Jiang, Ding-Wen; Wang, Qing-Rong

2017-10-27

, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and amino acid composition analyses of SSC demonstrated that SSC is type I collagen. SSCS had a homogeneous porous structure of approximately 200 μm, porosity rate of 83.57% ± 2.64%, water vapor transmission ratio (WVTR) of 4500 g/m 2 , tensile strength of 1.79 ± 0.41 N/mm, and elongation at break of 4.52% ± 0.01%. SSCS had significant beneficial effects on seawater-immersed wound healing. On the 3rd day, the healing rates in the GZ negative control, CS positive control and SSCS rats were 13.94% ± 5.50%, 29.40% ± 1.10% and 47.24% ± 8.40%, respectively. SSCS also enhanced TGF-β and CD31 expression in the initial stage of the healing period. The SSCS + PU dressing effectively protected wounds from seawater immersion for at least 4 h, and accelerated re-epithelialization, vascularization and granulation formation of seawater-immersed wounds in the earlier stages of wound healing, and as well as significantly promoted wound healing. The SSCS + PU dressing also enhanced expression of TGF-β and CD31. The effects of SSCS and SSCS + PU were superior to those of both the chitosan and gauze dressings. SSCS has significant positive effects on the promotion of seawater-immersed wound healing, and a SSCS + PU dressing effectively prevents seawater immersion, and significantly promotes seawater-immersed wound healing.

Comparative study of ice nucleating efficiency of K-feldspar in immersion and deposition freezing modes

Science.gov (United States)

Hiron, T.; Hoffmann, N.; Peckhaus, A.; Kiselev, A. A.; Leisner, T.; Flossmann, A. I.

2016-12-01

One of the main challenges in understanding the evolution of Earth's climate resides in the understanding the role of ice nucleation on the development of tropospheric clouds as well as its initiation. K-feldspar is known to be a very active ice nucleating particle and this study focuses on the characterization of its activity in two heterogeneous nucleation modes, immersion and deposition freezing.We use a newly built humidity-controlled cold stage allowing the simultaneous observation of up to 2000 identical 0.6-nanoliter droplets containing suspension of mineral dust particles. The droplets are first cooled down to observe immersion freezing, the obtained ice crystals are then evaporated and finally, the residual particles are exposed to the water vapor supersaturated with respect to ice.The ice nucleation abilities for the individual residual particles are then compared for the different freezing modes and correlation between immersion ice nuclei and deposition ice nuclei is investigated.Based on the electron microscopy analysis of the residual particles, we discuss the possible relationship between the ice nucleation properties of feldspar and its microstructure. Finally, we discuss the atmospheric implications of our experimental results, using DESCAM, a 1.5D bin-resolved microphysics model.

77 FR 12227 - Long Term 2 Enhanced Surface Water Treatment Rule: Uncovered Finished Water Reservoirs; Public...

Science.gov (United States)

2012-02-29

... Water Treatment Rule: Uncovered Finished Water Reservoirs; Public Meeting AGENCY: Environmental... review of the uncovered finished water reservoir requirement in the Long Term 2 Enhanced Surface Water... uncovered finished water reservoir requirement and the agency's Six Year Review process. EPA also plans to...

Fire-tube immersion heater optimization program and field heater audit program

Energy Technology Data Exchange (ETDEWEB)

Croteau, P. [Petro-Canada, Calgary, AB (Canada)

2007-07-01

This presentation provided an overview of the top 5 priorities for emission reduction and eco-efficiency by the Petroleum Technology Alliance of Canada (PTAC). These included venting of methane emissions; fuel consumption in reciprocating engines; fuel consumption in fired heaters; flaring and incineration; and fugitive emissions. It described the common concern for many upstream operating companies as being energy consumption associated with immersion heaters. PTAC fire-tube heater and line heater studies were presented. Combustion efficiency was discussed in terms of excess air, fire-tube selection, heat flux rate, and reliability guidelines. Other topics included heat transfer and fire-tube design; burner selection; burner duty cycle; heater tune up inspection procedure; and insulation. Two other programs were also discussed, notably a Petro-Canada fire-tube immersion heater optimization program and the field audit program run by Natural Resources Canada. It was concluded that improved efficiency involves training; managing excess air in combustion; managing the burner duty cycle; striving for 82 per cent combustion efficiency; and providing adequate insulation to reduce energy demand. tabs., figs.

The comparison of cold-water immersion and cold air therapy on maximal cycling performance and recovery markers following strength exercises

Directory of Open Access Journals (Sweden)

Kane J. Hayter

2016-03-01

Full Text Available This study examined the effects of cold-water immersion (CWI and cold air therapy (CAT on maximal cycling performance (i.e. anaerobic power and markers of muscle damage following a strength training session. Twenty endurance-trained but strength-untrained male (n = 10 and female (n = 10 participants were randomised into either: CWI (15 min in 14 °C water to iliac crest or CAT (15 min in 14 °C air immediately following strength training (i.e. 3 sets of leg press, leg extensions and leg curls at 6 repetition maximum, respectively. Creatine kinase, muscle soreness and fatigue, isometric knee extensor and flexor torque and cycling anaerobic power were measured prior to, immediately after and at 24 (T24, 48 (T48 and 72 (T72 h post-strength exercises. No significant differences were found between treatments for any of the measured variables (p > 0.05. However, trends suggested recovery was greater in CWI than CAT for cycling anaerobic power at T24 (10% ± 2%, ES = 0.90, T48 (8% ± 2%, ES = 0.64 and T72 (8% ± 7%, ES = 0.76. The findings suggest the combination of hydrostatic pressure and cold temperature may be favourable for recovery from strength training rather than cold temperature alone.

[Blood plasma volume dynamics in monkeys during immersion].

Science.gov (United States)

Krotov, V P; Burkovskaia, T E; Dotsenko, M A; Gordeev, Iu V; Nosovskiĭ, A M; Chel'naia, N A

2004-01-01

Dynamics of blood plasma volume (PV) was studied with indirect methods (hematocrit count, hemoglobin, total protein and high-molecular protein) during 9-d immersion of monkeys Macaca mulatta. The animals were donned in waterproof suits, motor restrained in space seat liners and immersed down to the xiphisternum. Two monkeys were immersed in the bath at one time. The suits were changed every day under ketamine (10 mg/kg of body mass). There were two groups with 12 animals in each. The first group was kept in the bath 3 days and the second--9 days. Prior to the experiment, the animals had been trained to stay in the seat liner put down into the dry bath. It was shown that already two days of exposure to the hydrostatic forces (approximately 15 mm Hg) and absence of negative pressure breathing reduced PV by 18-20% on the average in all animals. Subsequent PV dynamics was individual by character; however, PV deficit persisted during 4 days of immersion in the whole group. In this period, albumin filtration was increased significantly, whereas high-molecular protein filtration was increased to a less degree. During the remaining days in immersion PV regained normal values. Ten days of readaptation (reclined positioning of monkeys brought back into cage) raised VP beyond baseline values. This phenomenon can be attributed to the necessity to provide appropriate venous return and sufficient blood supply of organs and tissues following extension of blood vessels capacity.

Immersive bilingualism reshapes the core of the brain.

Science.gov (United States)

Pliatsikas, Christos; DeLuca, Vincent; Moschopoulou, Elisavet; Saddy, James Douglas

2017-05-01

Bilingualism has been shown to affect the structure of the brain, including cortical regions related to language. Less is known about subcortical structures, such as the basal ganglia, which underlie speech monitoring and language selection, processes that are crucial for bilinguals, as well as other linguistic functions, such as grammatical and phonological acquisition and processing. Simultaneous bilinguals have demonstrated significant reshaping of the basal ganglia and the thalamus compared to monolinguals. However, it is not clear whether these effects are due to learning of the second language (L2) at a very young age or simply due to continuous usage of two languages. Here, we show that bilingualism-induced subcortical effects are directly related to the amount of continuous L2 usage, or L2 immersion. We found significant subcortical reshaping in non-simultaneous (or sequential) bilinguals with extensive immersion in a bilingual environment, closely mirroring the recent findings in simultaneous bilinguals. Importantly, some of these effects were positively correlated to the amount of L2 immersion. Conversely, sequential bilinguals with comparable proficiency and age of acquisition (AoA) but limited immersion did not show similar effects. Our results provide structural evidence to suggestions that L2 acquisition continuously occurs in an immersive environment, and is expressed as dynamic reshaping of the core of the brain. These findings propose that second language learning in the brain is a dynamic procedure which depends on active and continuous L2 usage.

Rheology of granular flows immersed in a viscous fluid

International Nuclear Information System (INIS)

Amarsid, Lhassan

2015-01-01

We investigate the behavior of granular materials immersed in a viscous fluid by means of extensive simulations based on the Discrete Element Method for particle dynamics coupled with the Lattice Boltzmann method for the fluid. We show that, for a broad range of parameters such as shear rate, confining stress and viscosity, the internal friction coefficient and packing fraction are well described by a single 'visco-inertial' dimensionless parameter combining inertial and Stokes numbers. The frictional behavior under constant confining pressure is mapped into a viscous behavior under volume-controlled conditions, leading to the divergence of the effective normal and shear viscosities in inverse square of the distance to the critical packing fraction. The results are in excellent agreement with the experimental data of Boyer et al. (2011). The evolution of the force network in terms of connectivity and anisotropy as a function of the visco-inertial number, indicates that the increase of frictional strength is a direct consequence of structural anisotropy enhanced by both fluid viscosity and grain inertia. In view of application to a potential nuclear accident, we also study the fragmentation and flow of confined porous aggregates in a fluid under the action of local overpressures and pressure gradients as well as gravity-driven flow of immersed particles in an hourglass. (author)

The effect of soda immersion on nano hybrid composite resin discoloration

Directory of Open Access Journals (Sweden)

M. Chair Effendi

2014-03-01

Full Text Available Background: Composite resin is the tooth-colored restorative material which most of the people are fond of due to their aesthetic value. The composite resin discoloration may happen because of the intrinsic and extrinsic factors. Soda water is one of the beverages which can cause the composite resin discoloration. Purpose: The study was aimed to determine the effect of soda immersion on nano hybrid composite resin discoloration. Methods: The study was an experimental laboratory study using 100 shade A3 nano hybrid composite resin specimens with the diameter of 5 mm and density of 2mm. The samples were divided into 5 groups, each group was immersed in different beverages. The beverages were mineral water; lemon-flavored soda; strawberry-flavored soda; fruit punch-flavored soda; and orange-flavored soda for 3, 7, 14 and 21 days respectively, in the temperature of 37o C. The discoloration measurement utilizes Spectrophotometer, Vita Easy Shade, and uses CIEL*a*b* method. Results: The result showed that the duration of immersion in soda had an effect on the Nano hybrid composite resin discoloration. Strawberry and fruit punch- flavored soda were the most influential components toward the discoloration. Nevertheless, the generally-occurred discoloration was clinically acceptable (∆E ≤ 3,3. Conclusion: The study suggested that the soda immersion duration has effect on Nano hybrid composite resin discoloration.Latar belakang: Resin komposit adalah material sewarna gigi yang diminati masyarakat karena memiliki nilai estetik yang baik. Perubahan warna resin komposit dapat terjadi karena faktor intrinsik dan ekstrinsik. Minuman soda merupakan salah satu minuman yang dapat menyebabkan perubahan warna pada resin komposit. Tujuan: Tujuan dari penelitian ini untuk meneliti perubahan warna resin komposit nanohibrida akibat perendaman dalam minuman soda. Metode: Metode yang digunakan pada penelitian ini adalah eksperimental laboratorik dengan menggunakan

Immersive Learning Simulations in Aircraft Maintenance Training

Science.gov (United States)

2010-02-15

You might just get a “serious game,” or “as proposed by the eLearning Guild, you could get an Immersive Learning Simulation.”3 Quoting the... eLearning Guild, Caspian Learning, in a report for the United Kingdom Ministry of Defense, defined an Immersive Learning Simulation (ILS) as “an optimized...training is necessary, and will be for the foreseeable future , our current computer systems can provide realistic training that could save substantial time

Plasma immersion ion implantation into insulating materials

International Nuclear Information System (INIS)

Tian Xiubo; Yang Shiqin

2006-01-01

Plasma immersion ion implantation (PIII) is an effective surface modification tool. During PIII processes, the objects to be treated are immersed in plasmas and then biased to negative potential. Consequently the plasma sheath forms and ion implantation may be performed. The pre-requirement of plasma implantation is that the object is conductive. So it seems difficult to treat the insulating materials. The paper focuses on the possibilities of plasma implantation into insulting materials and presents some examples. (authors)

Effects of light emitting diode (LED) therapy and cold water immersion therapy on exercise-induced muscle damage in rats.

Science.gov (United States)

Camargo, Mariana Zingari; Siqueira, Cláudia Patrícia Cardoso Martins; Preti, Maria Carla Perozim; Nakamura, Fábio Yuzo; de Lima, Franciele Mendes; Dias, Ivan Frederico Lupiano; Toginho Filho, Dari de Oliveira; Ramos, Solange de Paula

2012-09-01

The aim of this work is to analyze the effects of LED therapy at 940 nm or cold water immersion therapy (CWI) after an acute bout of exercise on markers of muscle damage and inflammation. Thirty-two male Wistar rats were allocated into four groups: animals kept at rest (control), exercised animals (E), exercised + CWI (CWI), and exercised + LED therapy (LED). The animals swam for 100 min, after which blood samples were collected for lactate analysis. Animals in the E group were returned to their cages without treatment, the CWI group was placed in cold water (10°C) for 10 min and the LED group received LED irradiation on both gastrocnemius muscles (4 J/cm(2) each). After 24 h, the animals were killed and the soleus muscles were submitted to histological analysis. Blood samples were used for hematological and CK analyses. The results demonstrated that the LED group presented fewer areas of muscle damage and inflammatory cell infiltration and lower levels of CK activity than the E group. Fewer areas of damaged muscle fiber were observed in the LED group than in CWI. CWI and LED did not reduce edema areas. Hematological analysis showed no significant effect of either treatment on leukocyte counts. The results suggest that LED therapy is more efficient than CWI in preventing muscle damage and local inflammation after exercise.

The Feel Good Factor: Comparing Immersion by Design and Immersion by Default Models

Science.gov (United States)

Gallagher, Fiona; Leahy, Angela

2014-01-01

This article presents findings from an exploratory research project entitled "Gaelscoileanna and Multicultural classrooms: the potential for transfer to enhance L2 learning experiences". The project focussed on two language immersion contexts in Ireland which, despite obvious differences, share a range of significant commonalities. One…

Measuring participants' immersion in healthcare simulation: the development of an instrument.

Science.gov (United States)

Hagiwara, Magnus Andersson; Backlund, Per; Söderholm, Hanna Maurin; Lundberg, Lars; Lebram, Mikael; Engström, Henrik

2016-01-01

Immersion is important for simulation-based education; however, questionnaire-based instruments to measure immersion have some limitations. The aim of the present work is to develop a new instrument to measure immersion among participants in healthcare simulation scenarios. The instrument was developed in four phases: trigger identification, content validity scores, inter-rater reliability analysis and comparison with an existing immersion measure instrument. A modified Delphi process was used to develop the instrument and to establish validity and reliability. The expert panel consisted of 10 researchers. All the researchers in the team had previous experience of simulation in the health and/or fire and rescue services as researchers and/or educators and simulation designers. To identify triggers, the panel members independently screened video recordings from simulation scenarios. Here, a trigger is an event in a simulation that is considered a sign of reduced or enhanced immersion among simulation participants. The result consists of the Immersion Score Rating Instrument (ISRI). It contains 10 triggers, of which seven indicate reduced and three enhanced immersion. When using ISRI, a rater identifies trigger occurrences and assigns them strength between 1 and 3. The content validity analysis shows that all the 10 triggers meet an acceptable content validity index for items (I-CVI) standard. The inter-rater reliability (IRR) among raters was assessed using a two-way mixed, consistency, average-measures intra-class correlation (ICC). The ICC for the difference between weighted positive and negative triggers was 0.92, which indicates that the raters are in agreement. Comparison with results from an immersion questionnaire mirrors the ISRI results. In conclusion, we present a novel and non-intrusive instrument for identifying and rating the level of immersion among participants in healthcare simulation scenarios.