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Sample records for 133xe washout technique

  1. Penile xenon (/sup 133/Xe) washout: a rapid method of screening for vasculogenic impotence

    SciTech Connect

    Nseyo, U.O.; Wilbur, H.J.; Kang, S.A.; Flesh, L.; Bennett, A.H.

    1984-01-01

    The radioactive inert gas xenon (/sup 133/Xe) is a well-established isotopic indicator used to assess vascular status in many organ systems. Xenon-133 was used to evaluate male impotence. Xenon-133 was injected subcutaneously at the level of the coronal sulcus in the detumescent state. Using the gamma camera, sequential images were obtained and computer-generated curves calculated. The clearance time for 50 per cent washout of the injected /sup 133/Xe (T1/2) was then calculated for each patient, as well as a control group. Preliminary findings indicate a correlation with such established techniques of evaluating erectile impotence as history, physical examination, penile pulse Doppler tracings, and brachial-penile blood pressure index. The xenon-133 washout study was a rapid, minimally invasive, reproducible, and cost-effective method of screening those impotent patients for vasculogenic etiology of their erectile impotence. We recommend the addition of this method to the surgeon engaged in the care of impotent males.

  2. A semiconductor silicon PIN diode matrix detector for measurement of 133Xe washout in small regional skin areas.

    PubMed

    Jensen, J H; Sørensen, J L; Hauge, E N; Sejrsen, P; Bojsen, J

    1993-05-01

    Local variations in microvascularization are expected in lesions and lesion-free skin of patients with pressure sores. To investigate these variations, methods for studies of the regional blood flow rate within small skin areas are needed. Regional blood flow can be estimated by measuring the washout of 133Xe from the tissue. This study describes a 2 x 12 Si PIN diode matrix detector capable of 133Xe detection, and equipped with a collimator to improve the spatial resolution. Thus the regional blood flow in subcutaneous skin areas down to about 2 cm2 can be investigated when the atraumatic epicutaneous labelling technique is used. The capability of the matrix detector and its collimator is described by laboratory investigations. In pilot investigations three normal subjects and three paraplegics with pressure sores were studied. In each individual study the detector matrix was divided into six square areas containing four diode detectors each. Thus six 133Xe disappearance rate constants from adjacent subcutaneous tissue could be determined simultaneously. PMID:8334415

  3. Studies on 133Xe wash-out from human skin: quantitative measurements of blood flow in normal and corticosteroid-treated skin.

    PubMed

    Kristensen, J K; Wadskov, S

    1977-04-01

    Blood flow was measured by the 133Xe technique in normal and corticosteroid-treated skin. Epicutaneous and intracutaneous methods of tracer application were compared in normal skin. The two labeling methods were equally suitable for measuring cutaneous blood flow provided calculations in both cases were based on a biexponential resolution of the wash-out curve in its cutaneous and subcutaneous components and provided the traumatic hyperemia phase was considered, when intracutaneous application of the tracer was used. Results were invalidated if calculations were based on initial slope of the wash-out curves.Topical application of beta-methasone valerate in a reduction in cutaneous blood flow as measured by the intracutaneous technique with curve resolution, whereas no effect could be demonstrated when calculations were based on the initial slopes of the curves. The 133Xe technique is a simple and reliable method for measuring cutaneous blood flow, which might prove useful in estimations of penetration ability and potency of topical corticosteroids.

  4. Cerebral blood flow studied by /sup 133/Xe inhalation technique in parkinsonism: loss of hyperfrontal pattern

    SciTech Connect

    Bes, A.; Gueell, A.; Fabre, N.; Dupui, P.; Victor, G.; Geraud, G.

    1983-03-01

    Cerebral blood flow (grey matter flow) in parkinsonism requires further investigation. The noninvasive method of /sup 133/Xe inhalation permits study of larger numbers of subjects than previously used invasive techniques such as the intracarotid /sup 133/Xe injection method. Measurements were made in this laboratory in 30 subjects having Parkinson's disease. Mean hemispheric blood flow (F1) values were 70.4 +/- 9.3 ml/100 g/min, compared to 76.3 for a group of age-matched normal subjects, which is a decrease of -7.8%. The most striking difference was the loss of the hyperfrontal distribution in parkinsonism. The prefrontal F1 values were only 1.8% greater than the hemisphere grey matter flow, compared with 8.5% in controls of a similar age group.

  5. Intraoperative sup 133 Xe cerebral blood flow measurements by intravenous versus intracarotid methods

    SciTech Connect

    Young, W.L.; Prohovnik, I.; Schroeder, T.; Correll, J.W.; Ostapkovich, N. )

    1990-10-01

    To document the comparability of cerebral blood flow (CBF) values determined by quantification of 133Xe washout after either intravenous or intracarotid administration, 12 patients undergoing elective carotid endarterectomy anesthetized with N2O/O2 and either isoflurane or halothane were studied. Scintillation counters were placed over the middle cerebral artery territory ipsilateral to the operated carotid artery. CBF was measured by the intravenous method during dissection of the carotid sheath and was calculated as the initial slope index from head washout curves collected for 11 min after injection of 10-20 mCi 133Xe in saline into a large vein. Immediately prior to carotid occlusion, CBF was determined by direct injection of 1 mCi 133Xe in saline into either the internal carotid artery or the common carotid artery with the external carotid artery occluded. For the intracarotid injections, the initial slope was calculated from the 1st min of washout. Data were analyzed by linear regression and analysis of variance. Values are expressed as mean +/- SD. The mean CBF for intravenous and intracarotid methods were both 29 +/- 10 ml.100 g-1.min-1. The correlation between CBF measured by intravenous and intracarotid methods was excellent and was described by the line y = x + 0.6, r = 0.92. We conclude that in the flow range studied, the intravenous technique may be applied to measure CBF in physiologically stable situations in which direct intracarotid injection is not feasible.

  6. Reproducibility of the /sup 133/Xe inhalation technique in resting studies: task order and sex related effects in healthy young adults

    SciTech Connect

    Warach, S.; Gur, R.C.; Gur, R.E.; Skolnick, B.E.; Obrist, W.D.; Reivich, M.

    1987-12-01

    Repeated applications of the /sup 133/Xe inhalation technique for measuring regional CBF (rCBF) were made during consecutive resting conditions in a sample of young healthy subjects. Subjects were grouped by order and by sex (nine had resting studies as the initial two measurements in a series of four measurement (six men, three women) and six had these measurements later (two men, four women)). Three flow parameters were examined: f1 (fast flow) and IS (initial slope) for gray matter CBF, and CBF-15 for mean CBF (gray and white matter over 15-min integration), as well as w1, the percentage of tissue with fast clearing characteristics. With all groups combined, there were no significant differences between the two resting measurements, and high test-retest correlations were obtained for the flow parameters and w1. Analyses by order and sex grouping revealed, for the flow parameters, significant interactions of test-retest difference with order. Repeated initial studies showed reduced CBF from the first to second measurement, whereas resting studies performed later in the series showed no reduction. Interactions for test-retest difference with sex indicated that reduced CBF in serial measures was more pronounced for women. No hemispheric or regional specificity to account for these effects was found. Correction for PaCO/sub 2/ differences did not alter these results. The results resemble data regarding habituation effects measured for other psychophysiologic measures, and suggest that reduction in CBF for consecutive measurements made on the same day may reflect habituation. This underscores the importance of controlling for effects of habituation on serial measurements of CBF and metabolism.

  7. Evaluation of 133Xe and 133Xe(m) decay data.

    PubMed

    Galán, M

    2009-01-01

    This paper presents the decay data evaluation of (133)Xe and (133)Xe(m), which includes the most recent available data, such as half-life results and gamma-ray intensities that have not been considered in previous evaluations. The adopted internal conversion coefficients (ICC) have been calculated using the 'Frozen Orbital' approximation and are compared here to recent measured values. Recent Q-value tabulations, recommended gamma-ray energies for calibrations, as well as new evaluated gamma-ray intensities for the 81- and 233-keV lines (37.0 (3)% and 10.16 (13)%, respectively) are also presented in this evaluation. Atomic radiation emission probabilities (X-ray and Auger electron) associated with nuclear radiations have been deduced and also included in this work. PMID:18805017

  8. Detection of (133)Xe from the Fukushima nuclear power plant in the upper troposphere above Germany.

    PubMed

    Simgen, Hardy; Arnold, Frank; Aufmhoff, Heinfried; Baumann, Robert; Kaether, Florian; Lindemann, Sebastian; Rauch, Ludwig; Schlager, Hans; Schlosser, Clemens; Schumann, Ulrich

    2014-06-01

    After the accident in the Japanese Fukushima Dai-ichi nuclear power plant in March 2011 large amounts of radioactivity were released and distributed in the atmosphere. Among them were also radioactive noble gas isotopes which can be used as tracers to test global atmospheric circulation models. This work presents unique measurements of the radionuclide (133)Xe from Fukushima in the upper troposphere above Germany. The measurements involve air sampling in a research jet aircraft followed by chromatographic xenon extraction and ultra-low background gas counting with miniaturized proportional counters. With this technique a detection limit of the order of 100 (133)Xe atoms in liter-scale air samples (corresponding to about 100 mBq/m(3)) is achievable. Our results provide proof that the (133)Xe-rich ground level air layer from Fukushima was lifted up to the tropopause and distributed hemispherically. Moreover, comparisons with ground level air measurements indicate that the arrival of the radioactive plume at high altitude over Germany occurred several days before the ground level plume. PMID:24607612

  9. Detection of (133)Xe from the Fukushima nuclear power plant in the upper troposphere above Germany.

    PubMed

    Simgen, Hardy; Arnold, Frank; Aufmhoff, Heinfried; Baumann, Robert; Kaether, Florian; Lindemann, Sebastian; Rauch, Ludwig; Schlager, Hans; Schlosser, Clemens; Schumann, Ulrich

    2014-06-01

    After the accident in the Japanese Fukushima Dai-ichi nuclear power plant in March 2011 large amounts of radioactivity were released and distributed in the atmosphere. Among them were also radioactive noble gas isotopes which can be used as tracers to test global atmospheric circulation models. This work presents unique measurements of the radionuclide (133)Xe from Fukushima in the upper troposphere above Germany. The measurements involve air sampling in a research jet aircraft followed by chromatographic xenon extraction and ultra-low background gas counting with miniaturized proportional counters. With this technique a detection limit of the order of 100 (133)Xe atoms in liter-scale air samples (corresponding to about 100 mBq/m(3)) is achievable. Our results provide proof that the (133)Xe-rich ground level air layer from Fukushima was lifted up to the tropopause and distributed hemispherically. Moreover, comparisons with ground level air measurements indicate that the arrival of the radioactive plume at high altitude over Germany occurred several days before the ground level plume.

  10. Combined technetium radioisotope penile plethysmography and xenon washout: A technique for evaluating corpora cavernosal inflow and outflow during early tumescence

    SciTech Connect

    Schwartz, A.N.; Graham, M.M. )

    1991-03-01

    Combined technetium radioisotope penile plethysmography and xenon washout is a new technique that measures both corporal arterial inflow and venous sinusoidal outflow during early tumescence in patients with erectile dysfunction. Fourteen patients were studied using 99mTc-RBCs to measure inflow and 133Xe or 127Xe in saline to measure outflow. Tumescence was induced by injecting papaverine intracorporally. Peak corporal rates corrected for inflow (r = 0.88) and uncorrected for outflow (r = 0.91) and change in volume over 2 min centered around peak inflow (r = 0.96) all correlated with angiography. Outflow measurements did not correlate with intracorporal resistance. Thus, outflow rates alone could not be used to predict venous sinusoidal competence. Normal inflow rate is greater than 20 ml/min; probable normal 12-20; indeterminate inflow 7-12; and abnormal inflow less than 7 ml/min. Technetium-99m radioisotope penile plethysmography and xenon washout can be performed together and both provide a method for simultaneously evaluating the relationship between corporal inflow and outflow rates in patients with erectile dysfunction.

  11. Dose dependence of the production yield of endohedral 133Xe-fullerene by ion implantation

    NASA Astrophysics Data System (ADS)

    Watanabe, S.; Ishioka, N. S.; Shimomura, H.; Muramatsu, H.; Sekine, T.

    2003-05-01

    The production yield of endohedral 133Xe-fullerene by ion implantation has been studied by taking advantage of the radioactivity of 133Xe. Fullerene targets, which were produced by vacuum evaporation of C 60 or C 70 on a Ni backing, were bombarded with 30-38 keV 133Xe ions by using an isotope separator at doses ranging from 1 × 10 12 to 1 × 10 14 cm -2. The production yield of endohedral 133Xe-fullerene was determined by an high performance liquid chromatography analysis following the dissolution of the targets in o-dichlorobenzene. It was found that the production yield decreased with increasing dose and incident energy, and the production yield of 133Xe@C 70 was higher than that of 133Xe@C 60 for the same dose and incident energy. Those production yields are discussed in connection with amorphization of fullerene molecules in collisions with 133Xe ions.

  12. Response of Panasonic dosimeters to submersion exposure by 133Xe.

    PubMed

    Hoffman, J M; Catchen, G L

    1990-01-01

    The dose response to 133Xe radiation of several types of Panasonic 800 series thermoluminescent dosimeters (TLD) were evaluated. The dosimeters were exposed by submersion in 133Xe gas. The relative sensitivities of the lithium borate and the calcium sulfate phosphors were determined for several configurations. The TLDs were exposed in the holders (as the devices came from the vendor) with various shields covering the elements, and they were exposed with the TLDs removed from the holders. Some dosimeters were exposed, both in holders and out of holders (TL insert only configuration), both in plastic bags and free in air. For the in-holder configuration, the responses of the heavily shielded (greater than 170 mg cm-2) elements were used to obtain the photon dose-rate component, and the responses of the lightly shielded (less than 13 mg cm-2) element were used to obtain the beta component. Similarly, for the insert-only configurations, the observed over-response of the calcium sulfate phosphors to low-energy photons could be used to separate the beta dose rate component. By using the calculated beta doses, correction factors were determined for the apparent under-responses of the elements to beta radiation. The results of both methods are consistent. These results also suggest that the beta component could be used in environmental monitoring as a more sensitive means to determine 133Xe activities in clouds and to separate some of the effects of submersion exposure from those of distant exposure.

  13. Analytical evaluation of two motion washout techniques

    NASA Technical Reports Server (NTRS)

    Young, L. R.

    1977-01-01

    Practical tools were developed which extend the state of the art of moving base flight simulation for research and training purposes. The use of visual and vestibular cues to minimize the actual motion of the simulator itself was a primary consideration. The investigation consisted of optimum programming of motion cues based on a physiological model of the vestibular system to yield 'ideal washout logic' for any given simulator constraints.

  14. Evaluation of 133Xe radiation exposure dosimetry for workers in nuclear medicine laboratories.

    PubMed

    Piltingsrud, H V; Gels, G L

    1982-06-01

    Evaluation of past studies of 133Xe dosimetry and nuclear medicine laboratory air concentrations of 133Xe indicates that significant levels of 133Xe may exist in routine operational environments of a nuclear medicine laboratory. This leads to the question of whether present health physics radiation control methods are adequate to keep occupational personnel exposures within acceptable levels. It would appear that if personnel dosimeters (film and TLD badges) respond properly to the radiation of 133Xe, normal health physics control procedures are probably adequate. If they do not respond adequately, personnel exposures may exceed recommended levels and special instrumentation or administrative procedures are called for. Therefore, the first step in studying potential problems in the subject area is to evaluate the response of a variety of personnel radiation dosimeters to 133Xe. This paper describes the methods and materials used to expose personnel dosimeters to known amounts of 133Xe radiations in an exposure chamber constructed at the BRH Nuclear Medicine Laboratory. Also presented are calculated values for Dose Equivalents (D.E.) in a phantom from external radiation resulting from immersion in clouds having a constant concentration of 133Xe but varying cloud radii. This implies the relative importance of the beta and the X + gamma radiation responses of the personnel dosimeters under various exposure conditions. Results of this study indicate that none of the dosimeter systems evaluated provide adequate performance for use as a primary indicator of the D.E. resulting from 133Xe radiations for a worker in a nuclear medicine laboratory, and that personnel dosimetry considerations in 133Xe-containing atmospheres are very dependent on the radii of the 133Xe clouds.

  15. Prospective use of xenon /sup 133/Xe clearance for amputation level selection

    SciTech Connect

    Moore, W.S.; Henry, R.E.; Malone, J.M.; Daly, M.J.; Patton, D.; Childers, S.J.

    1981-01-01

    Xenon /sup 133/Xe clearance was used to select the most distal amputation level that would allow sufficient blood flow for healing. Capillary blood flow was first measured at the most distal potential amputation level, then at successive proximal levels until an amputation site was found that had a capillary skin blood flow rate greater than or equal to 2.6 mL/min/100 g of tissue. Xenon /sup 133/Xe in saline was injected intracutaneously at each level, and flow rates were determined using a gamma camera interfaced with a computer system programmed for the Ketty-Schmidt formula modified for capillary blood flow. There were 45 cases, including one toes, six transmetatarsal, five Syme's, 25 below-knee, four knee disarticulation, three above-knee, and one hip disarticulation amputation. All amputations in patients with flow rates exceeding 2.4 mL/min/100 g of tissue healed, with two exceptions.

  16. Response of Panasonic dosimeters to submersion exposure by sup 133 Xe

    SciTech Connect

    Hoffman, J.M.; Catchen, G.L. )

    1990-01-01

    The dose response to {sup 133}Xe radiation of several types of Panasonic 800 series thermoluminescent dosimeters (TLD) were evaluated. The dosimeters were exposed by submersion in {sup 133}Xe gas. The relative sensitivities of the lithium borate and the calcium sulfate phosphors were determined for several configurations. The TLDs were exposed in the holders (as the devices came from the vendor) with various shields covering the elements, and they were exposed with the TLDs removed from the holders. Some dosimeters were exposed, both in holders and out of holders (TL insert only configuration), both in plastic bags and free in air. For the in-holder configuration, the responses of the heavily shielded (greater than 170 mg cm-2) elements were used to obtain the photon dose-rate component, and the responses of the lightly shielded (less than 13 mg cm-2) element were used to obtain the beta component. Similarly, for the insert-only configurations, the observed over-response of the calcium sulfate phosphors to low-energy photons could be used to separate the beta dose rate component. By using the calculated beta doses, correction factors were determined for the apparent under-responses of the elements to beta radiation. The results of both methods are consistent. These results also suggest that the beta component could be used in environmental monitoring as a more sensitive means to determine {sup 133}Xe activities in clouds and to separate some of the effects of submersion exposure from those of distant exposure.

  17. Concentration Independent Calibration of β-γ Coincidence Detector Using 131mXe and 133Xe

    SciTech Connect

    McIntyre, Justin I.; Cooper, Matthew W.; Carman, April J.; Bowyer, Ted W.; Day, Anthony R.; Haas, Derek A.; Hayes, James C.; Heimbigner, Tom R.; Hubbard, Charles W.; Litke, Kevin E.; Ripplinger, Michael D.; Schrom, Brian T.; Suarez, Reynold

    2009-12-01

    Absolute efficiency calibration of radiometric detectors is frequently difficult and requires careful detector modeling and accurate knowledge of the radioactive source used. In the past we have calibrated the b-g coincidence detector of the Automated Radioxenon Sampler/Analyzer (ARSA) using a variety of sources and techniques which have proven to be less than desirable.[1] A superior technique has been developed that uses the conversion-electron (CE) and x-ray coincidence of 131mXe to provide a more accurate absolute gamma efficiency of the detector. The 131mXe is injected directly into the beta cell of the coincident counting system and no knowledge of absolute source strength is required. In addition, 133Xe is used to provide a second independent means to obtain the absolute efficiency calibration. These two data points provide the necessary information for calculating the detector efficiency and can be used in conjunction with other noble gas isotopes to completely characterize and calibrate the ARSA nuclear detector. In this paper we discuss the techniques and results that we have obtained.

  18. Measured absorbed dose rates from semi-infinite hemispherical volumes of 133Xe.

    PubMed

    Munyon, W J; Barber, D E; Howley, J R

    1986-07-01

    Surface absorbed dose rates from different hemispheric volumes of 133Xe have been measured directly with an extrapolation chamber. The results indicate that a linear relationship exists between the radius of the cloud volume and the surface absorbed dose rate for radii between 0 and 23 cm. If cloud volumes with radii larger than 23 cm are taken to be infinite with respect to the range of the charged particles emitted, the absorbed dose rate calculated based on that assumption will be within the uncertainty of any measurement of absorbed dose rate that might be made. For hemispheric volumes having radii less than or equal to 23 cm, the surface absorbed dose rate in tissue-equivalent material, in mGy h-1, is approximated (+/- 20%) by the product of [1.30 mGy h-1 cm-1 kBq-1 cm3] X [cloud radius, cm] X [cloud activity concentration, kBq cm-3].

  19. /sup 133/Xe blood flow monitoring during arteriovenous malformation resection: a case of intraoperative hyperperfusion with subsequent brain swelling

    SciTech Connect

    Young, W.L.; Solomon, R.A.; Prohovnik, I.; Ornstein, E.; Weinstein, J.; Stein, B.M.

    1988-04-01

    Measurement of regional cerebral blood flow (rCBF) using the i.v. 133Xe technique was carried out during resection of a right temporooccipital arteriovenous malformation (AVM) with ipsilateral middle and posterior cerebral arterial supply. Intraoperatively, a rCBF detector was in place over the right frontotemporal area, about 5 to 6 cm from the border of the AVM. Anesthesia was 0.75% isoflurane in oxygen and nitrous oxide. After dural exposure, the rCBF was 27 ml/100 g/min at a pCO2 of 29 mm Hg and a mean arterial pressure (MAP) of 90 mm Hg. The pCO2 was then elevated to 40 mm Hg, and the rCBF was increased to 55 ml/100 g/min at a MAP of 83 mm Hg. After AVM removal, the rCBF rose to 50 ml/100 g/min at a pCO2 of 27 mm Hg and a MAP of 75 mm Hg. The pCO2 was elevated to 33 mm Hg and the rCBF increased to 86 ml/100 g/min at a MAP of 97 mm Hg. During skin closure, the rCBF was 94 ml/100 g/min at a pCO2 of 26 mm Hg and a MAP of 97 mm Hg. The patient was neurologically normal postoperatively except for a mild, new visual field defect. After 2 to 3 days, the patient gradually developed lethargy, confusion, and nausea with relatively normal blood pressure. An angiogram revealed residual enlargement of the posterior cerebral artery feeding vessel. Computed tomography showed edema extending from the area of AVM resection as far as the frontal region, producing a significant midline shift anteriorly. Intraoperative rCBF monitoring revealed significant hyperperfusion after AVM resection, which was associated with signs and symptoms of the normal perfusion pressure breakthrough syndrome.

  20. Atmospheric transport modelling of time resolved 133Xe emissions from the isotope production facility ANSTO, Australia.

    PubMed

    Schöppner, M; Plastino, W; Hermanspahn, N; Hoffmann, E; Kalinowski, M; Orr, B; Tinker, R

    2013-12-01

    The verification of the Comprehensive Nuclear-Test Ban Treaty (CTBT) relies amongst other things on the continuous and worldwide monitoring of radioxenon. The characterization of the existing and legitimate background, which is produced mainly by nuclear power plants and isotope production facilities, is of high interest to improve the capabilities of the monitoring network. However, the emissions from legitimate sources can usually only be estimated. For this paper historic source terms of (133)Xe emissions from the isotope production facility at ANSTO, Sydney, Australia, have been made available in a daily resolution. Based on these high resolution data, different source term sets with weekly, monthly and yearly time resolution have been compiled. These different sets are then applied together with atmospheric transport modelling (ATM) to predict the concentration time series at two radioxenon monitoring stations. The results are compared with each other in order to examine the improvement of the prediction capability depending on the used time resolution of the most dominant source term in the region.

  1. Characterization of Carbon Dioxide Washout Measurement Techniques in the Mark-III Space Suit

    NASA Technical Reports Server (NTRS)

    Bekdash, O.; Norcross, J.; Meginnis, I.

    2016-01-01

    Providing adequate carbon dioxide (CO2) washout is essential to the reduction of risk in performing suited operations. Long term CO2 exposure can lead to symptoms such as headache, lethargy, and dizziness. Thus maintaining adequate CO2 washout in both ground testing and during in flight EVAs is a requirement of current and future suit designs. It is necessary to understand the inspired CO2 of suit wearers such that future requirements for space suits appropriately address the risk of inadequate washout. Testing conducted by the EVA Physiology Laboratory at the NASA Johnson Space Center aimed to characterize a method for noninvasively measuring inspired oronasal CO2 under pressurized suited conditions in order to better inform requirements definition and verification techniques for future CO2 washout limits in space suits. Based on a meta-analysis of those studies it was decided to test a nasal cannula as it is a commercially available device, would not impede suit ventilation delivery, and is placed directly in the breathing path of the user.

  2. Characterization of Carbon Dioxide Washout Measurement Techniques in the Mark-III Space Suit

    NASA Technical Reports Server (NTRS)

    Meginnis, I; Norcross, J.; Bekdash, O.

    2016-01-01

    techniques for future CO2 washout limits in space suits

  3. Cerebral hemodynamics in normal-pressure hydrocephalus. Evaluation by 133Xe inhalation method and dynamic CT study

    SciTech Connect

    Tamaki, N.; Kusunoki, T.; Wakabayashi, T.; Matsumoto, S.

    1984-09-01

    Cerebral hemodynamics in 31 patients with suspected normal-pressure hydrocephalus were studied by means of the xenon-133 (133Xe) inhalation method and on dynamic computerized tomography (CT) scanning. Cerebral blood flow (CBF) is reduced in all patients with dementia. Hypoperfusion was noted in a frontal distribution in these patients compared with normal individuals. There was no difference in CBF patterns between patients with good and those with poor outcome. The CBF was increased following cerebrospinal fluid (CSF) shunting in patients who responded to that procedure: increase in flow correlated with clinical improvement, frontal and temporal lobe CBF was most markedly increased, and the CBF pattern became normal. In contrast, CBF was decreased after shunt placement in patients who were considered to have suffered from degenerative dementia, as evidenced by non-response to shunting. Dynamic computerized tomography studies demonstrated that patients with a good outcome showed a postoperative reduction in mean transit time of contrast material, most prominent in the frontal and temporal gray matter, and slight in the deep frontal structures, but not in the major cerebral vessels. Patients with poor outcome after shunting, however, had an increase in transit time in all regions. This corresponded well with the results as determined by the 133Xe inhalation method.

  4. Characterization of Carbon Dioxide Washout Measurement Techniques in the Mark-III Space Suit

    NASA Technical Reports Server (NTRS)

    Norcross, J.; Bekdash, O.; Meginnis, I.

    2016-01-01

    Providing adequate carbon dioxide (CO2) washout is essential to the reduction of risk in performing suited operations. Long term CO2 exposure can lead to symptoms such as headache, lethargy, dizziness, and in severe cases can lead to unconsciousness and death. Thus maintaining adequate CO2 washout in both ground testing and during in flight EVAs is a requirement of current and future suit designs. It is necessary to understand the inspired CO2 of suit wearers such that future requirements for space suits appropriately address the risk of inadequate washout. Testing conducted by the EVA Physiology Laboratory at the NASA Johnson Space Center aimed to characterize a method for noninvasively measuring inspired oronasal CO2 under pressurized suited conditions in order to better inform requirements definition and verification techniques for future CO2 washout limits in space suits. Prior work conducted by the EPL examined several different wearable, respirator style, masks that could be used to sample air from the vicinity surround the nose and mouth of a suited test subject. Previously published studies utilized these masks, some being commercial products and some novel designs, to monitor CO2 under various exercise and flow conditions with mixed results for repeatability and/or consistency between subjects. Based on a meta-analysis of those studies it was decided to test a nasal cannula as it is a commercially available device that is placed directly in the flow path of the user as they breathe. A nasal cannula was used to sample air inhaled by the test subjects during both rest and exercise conditions. Eight subjects were tasked with walking on a treadmill or operating an arm ergometer to reach target metabolic rates of 1000, 2000, and 3000 BTU/hr. Suit pressure was maintained at 4.3 psid for all tests, with supply flow rates of 6, 4, and 2 actual cubic feet per minute depending on the test condition. Each test configuration was conducted twice with subjects breathing

  5. [Evaluation of gamma camera collimator for regional cerebral blood flow measurements using a 133Xe inhalation method].

    PubMed

    Saegusa, K; Arimizu, N; Uematsu, S

    1984-09-01

    In the measurements of regional cerebral blood flow (rCBF) using inhalation of 133Xe gas, the activity present is generally limited in lower levels than those of usual brain scintigraphy. Measurements with low count-rate are usually resulted in diminishing the accuracies of results obtained. Therefore, it is necessary to make measurements using a high sensitive collimator for getting as much count-rate as possible when a gamma camera is used. The relationships among sensitivity and structures of multi-parallel collimator were mathematically analyzed. The results of analysis suggested that sensitivity usually increased by using a collimator with holes of reduced height and diameter. A prototype multi-parallel collimator with holes of low height and small diameter was made in our laboratory for testing sensitivity and resolution. The collimator possessing 1141 holes of 6 mm phi in hole diameter, 1.5 cm is hole height and septal thickness of 1 mm lead showed 24 times more sensitive than those of a general all purpose collimator supplied by the manufacturer. However, resolution measured in FWHM was of 9 to 14 mm at the collimator face and of 29 to 38 mm at 5 cm from the face. The results indicated that this collimator was useful enough in rCBF measurements with 133Xe inhalation using a gamma camera. The mathematical analysis however, suggested that optimum collimator for rCBF measurements was approximate 4.5 mm phi in hole diameter and 1.0 cm in hole height. PMID:6515050

  6. Modification of the open circuit N2 washout technique for measurement of functional residual capacity in premature infants.

    PubMed

    Hentschel, R; Suska, A; Volbracht, A; Brune, T; Jorch, G

    1997-06-01

    We compared the standard nitrogen (N2) washout technique for measuring functional residual capacity (FRC) with a modified technique that uses a helium/oxygen mixture (heliox) at different ratio instead of pure oxygen. The tests were made with a standard lung function system equipped with an ultraviolet (UV) analyzer for measurement of N2 concentrations in the expired gas. We examined models of "spontaneous breathing" and "mechanical ventilation," each with volumes of FRC in the range of a premature and a newborn lung (20-80 ml), using both techniques at different baseline inspired oxygen concentrations (FIO2). Correlations between known and measured volumes were high and identical for the two techniques (r = 0.996), and the mean error was not significantly different from zero (P = 0.111). Measurements of FRC in 6 infants gave a correlation coefficient of r = 0.989 between the two techniques; reproducibility, as measured by the coefficient of variation, was high, showing no significant differences between both techniques (P = 0.792). However, values of individual infants were different (P = 0.011), and the slope of the regression line relating measurements by the 2 techniques was 1.04, with an intercept on the y-axis at 1.46. We conclude that FRC can be measured with the modified N2 washout technique, using heliox as a washout gas. Volumes can be measured with high precision and reproducibility, even in premature infants with low lung volumes and/or high baseline FIO2. A correction factor may be necessary to equate FRC measurements made by oxygen-N2 vs. heliox-N2 washouts. Hyperoxemia and hypoxemia can be avoided by admixing different flows of oxygen to a standard heliox mixture.

  7. Relationship of 133Xe cerebral blood flow to middle cerebral arterial flow velocity in men at rest

    NASA Technical Reports Server (NTRS)

    Clark, J. M.; Skolnick, B. E.; Gelfand, R.; Farber, R. E.; Stierheim, M.; Stevens, W. C.; Beck, G. Jr; Lambertsen, C. J.

    1996-01-01

    Cerebral blood flow (CBF) was measured by 133Xe clearance simultaneously with the velocity of blood flow through the left middle cerebral artery (MCA) over a wide range of arterial PCO2 in eight normal men. Average arterial PCO2, which was varied by giving 4% and 6% CO2 in O2 and by controlled hyperventilation on O2, ranged from 25.3 to 49.9 mm Hg. Corresponding average values of global CBF15 were 27.2 and 65.0 ml 100 g min-1, respectively, whereas MCA blood-flow velocity ranged from 42.8 to 94.2 cm/s. The relationship of CBF to MCA blood-flow velocity over the imposed range of arterial PCO2 was described analytically by a parabola with the equation: CBF = 22.8 - 0.17 x velocity + 0.006 x velocity2 The observed data indicate that MCA blood-flow velocity is a useful index of CBF response to change in arterial PCO2 during O2 breathing at rest. With respect to baseline values measured while breathing 100% O2 spontaneously, percent changes in velocity were significantly smaller than corresponding percent changes in CBF at increased levels of arterial PCO2 and larger than CBF changes at the lower arterial PCO2. These observed relative changes are consistent with MCA vasodilation at the site of measurement during exposure to progressive hypercapnia and also during extreme hyperventilation hypocapnia.

  8. Sources of variability of resting cerebral blood flow in healthy subjects: a study using 133Xe SPECT measurements

    PubMed Central

    Henriksen, Otto M; Kruuse, Christina; Olesen, Jes; Jensen, Lars T; Larsson, Henrik B W; Birk, Steffen; Hansen, Jakob M; Wienecke, Troels; Rostrup, Egill

    2013-01-01

    Measurements of cerebral blood flow (CBF) show large variability among healthy subjects. The aim of the present study was to investigate the relative effect of established factors influencing CBF on the variability of resting CBF. We retrospectively analyzed spontaneous variability in 430 CBF measurements acquired in 152 healthy, young subjects using 133Xe single-photon emission computed tomography. Cerebral blood flow was correlated positively with both end-tidal expiratory PCO2 (PETCO2) and female gender and inversely with hematocrit (Hct). Between- and within-subject CO2 reactivity was not significantly different. Including PETCO2, Hct and gender in the model reduced between-subject and within-subject variance by 14% and 13.5%, respectively. Within-subject variability was mainly influenced by PETCO2 and between-subject variability mostly by Hct, whereas gender appeared to be of little added value when Hct was also accounted for. The present study confirms large between-subject variability in CBF measurements and that gender, Hct, and PETCO2 explain only a small part of this variability. This implies that a large fraction of CBF variability may be due to unknown factors such as differences in neuron density or metabolism that could be subject for further studies. PMID:23403374

  9. Adsorption and desorption of noble gases on activated charcoal: I. 133Xe studies in a monolayer and packed bed.

    PubMed

    Scarpitta, S C; Harley, N H

    1990-10-01

    Detailed desorption studies using petroleum-based activated charcoals were conducted in monolayers and packed beds. Less extensive studies were conducted on several other types of charcoal. Kinetic studies, using 133Xe, demonstrated the existence of a micropore volume with entrance capillaries that together determined the response characteristics of charcoal to external concentration gradients of tracer gases. This new two-phase model, composed of micropores and entrance capillaries, describes the desorption dynamics of an adsorbed gas in the presence of water vapor. Condensed water vapor in the entrance capillaries of the charcoal reduced the effective pore radius and increased the diffusion half-time. Water could also adversely affect the integrating capability of the charcoal dramatically if the adsorbed water completely blocked the entrance capillaries. The amount of adsorbed water required to block the capillaries varied with the charcoal type and was termed here as the "break-point." The desorption parameters measured in this work can be used to design an improved passive Rn monitor to effectively integrate during a 3-7 d exposure period by eliminating the adverse effects of water vapor. The improved canister design would provide more accurate and reproducible measurements of indoor Rn concentrations than are currently available. PMID:2398007

  10. SDAT – Analysis of 131mXe with 133Xe Interference

    SciTech Connect

    Biegalski, Steven R.; Foltz Biegalski, Kendra M.; Haas, Derek A.

    2009-12-01

    The Spectral Deconvolution Analysis Tool (SDAT) software was developed at The University of Texas at Austin. SDAT utilizes a standard spectrum technique for the analysis of beta-gamma coincidence spectra. Testing was performed on the software to compare the standard spectrum analysis technique with a region of interest (ROI) analysis technique. Experimentally produced standard spectra and sample data were produced at the Nuclear Engineering Teaching Laboratory (NETL) TRIGA reactor. The results of the testing showed that the standard spectrum technique had lower errors than the ROI analysis technique for samples with low counting statistics. In contrast, the ROI analysis technique outperformed the standard spectrum technique in high counting statistics samples. It was also shown that the standard spectrum technique benefitted from a compression of the number of channels within the spectra.

  11. Characterization of Carbon Dioxide Washout Measurement Techniques in the Mark-III Space Suit

    NASA Technical Reports Server (NTRS)

    Meginnis, Ian M.; Norcross, Jason; Bekdash, Omar; Ploutz-Snyder, Robert

    2016-01-01

    A space suit must provide adequate carbon dioxide (CO2) washout inside the helmet to prevent symptoms of hypercapnia. In the past, an oronasal mask has been used to measure the inspired air of suited subjects to determine a space suit's CO2 washout capability. While sufficient for super-ambient pressure testing of space suits, the oronasal mask fails to meet several human factors and operational criterion needed for future sub-ambient pressure testing (e.g. compatibility with a Valsalva device). This paper describes the evaluation of a nasal cannula as a device for measuring inspired air within a space suit. Eight test subjects were tasked with walking on a treadmill or operating an arm ergometer to achieve target metabolic rates of 1000, 2000, and 3000 British thermal units per hour (BTU/hr), at flow rates of 2, 4, and 6 actual cubic feet per minute (ACFM). Each test configuration was conducted twice, with subjects instructed to breathe either through their nose only, or however they felt comfortable. Test data shows that the nasal cannula provides more statistically consistent data across test subjects than the oronasal mask used in previous tests. The data also shows that inhaling/exhaling through only the nose provides a lower sample variance than a normal breathing style. Nose-only breathing reports better CO2 washout due to several possible reasons, including a decreased respiratory rate, an increased tidal volume, and because nose-only breathing directs all of the exhaled CO2 down and away from the oronasal region. The test subjects in this study provided feedback that the nasal cannula is comfortable and can be used with the Valsalva device.

  12. Cerebral hemodynamics in patients with moyamoya disease. A study of regional cerebral blood flow by the /sup 133/Xe inhalation method

    SciTech Connect

    Takeuchi, S.; Tanaka, R.; Ishii, R.; Tsuchida, T.; Kobayashi, K.; Arai, H.

    1985-05-01

    Regional cerebral blood flow was measured by the /sup 133/Xe inhalation method in 20 young patients with moyamoya disease and five young healthy volunteers. Most patients showed low values of mean hemispheric blood flow in both hemispheres. Regional cerebral blood flow was at a low value in the upper frontal region and at an almost average value in the posterotemporal and occipital regions, which was different from the ''hyperfrontal'' pattern in healthy volunteers. Regional cerebral blood flow was reduced evenly by hyperventilation. By 5% CO/sub 2/ inhalation, regional cerebral blood flow was increased in the temporooccipital regions and was nearly unchanged or decreased in the frontal region.

  13. Effects of selected materials and geometries on the beta dose equivalent rate in a tissue equivalent phantom immersed in infinite clouds of 133Xe.

    PubMed

    Piltingsrud, H V; Gels, G L

    1986-06-01

    Most calculations of dose equivalent (D.E.) rates at 70-micron tissue depths in tissue equivalent (T.E.) phantoms from infinite clouds (radius exceeds maximum beta range in air) of 133Xe do not consider the possible effects of clothing overlays. Consequently, a series of measurements were made using a 1-mm-thick plastic scintillation detector assembly mounted in a tissue equivalent (T.E.) phantom with an overlay of 70 micron of T.E. material. This assembly was placed in an infinite cloud containing a known concentration of 133Xe. Material samples were placed at selected distances from the detector phantom, both individually and in various combinations. Pulse-height spectra resulting from beta radiations were converted to relative D.E. rates at a 70-micron tissue depth. The relative D.E. rates were reduced from values with no clothing cover by as little as 45% when placing a single thin nylon cloth 1 cm from the phantom, to 94% for a T-shirt material plus wool material plus denim placed 1/2, 1 and 3 cm, respectively, from the phantom. The results indicate that even loosely fitting clothing can have an important effect on reducing the D.E. rate. Close-fitting clothing appears to provide better protection.

  14. Effects of selected materials and geometries on the beta dose equivalent rate in a tissue equivalent phantom immersed in infinite clouds of 133Xe.

    PubMed

    Piltingsrud, H V; Gels, G L

    1986-06-01

    Most calculations of dose equivalent (D.E.) rates at 70-micron tissue depths in tissue equivalent (T.E.) phantoms from infinite clouds (radius exceeds maximum beta range in air) of 133Xe do not consider the possible effects of clothing overlays. Consequently, a series of measurements were made using a 1-mm-thick plastic scintillation detector assembly mounted in a tissue equivalent (T.E.) phantom with an overlay of 70 micron of T.E. material. This assembly was placed in an infinite cloud containing a known concentration of 133Xe. Material samples were placed at selected distances from the detector phantom, both individually and in various combinations. Pulse-height spectra resulting from beta radiations were converted to relative D.E. rates at a 70-micron tissue depth. The relative D.E. rates were reduced from values with no clothing cover by as little as 45% when placing a single thin nylon cloth 1 cm from the phantom, to 94% for a T-shirt material plus wool material plus denim placed 1/2, 1 and 3 cm, respectively, from the phantom. The results indicate that even loosely fitting clothing can have an important effect on reducing the D.E. rate. Close-fitting clothing appears to provide better protection. PMID:3710789

  15. Effects of selected materials and geometries on the beta dose equivalent rate in a tissue equivalent phantom immersed in infinite clouds of 133Xe

    SciTech Connect

    Piltingsrud, H.V.; Gels, G.L.

    1986-06-01

    Most calculations of dose equivalent (D.E.) rates at 70-micron tissue depths in tissue equivalent (T.E.) phantoms from infinite clouds (radius exceeds maximum beta range in air) of /sup 133/Xe do not consider the possible effects of clothing overlays. Consequently, a series of measurements were made using a 1-mm-thick plastic scintillation detector assembly mounted in a tissue equivalent (T.E.) phantom with an overlay of 70 micron of T.E. material. This assembly was placed in an infinite cloud containing a known concentration of /sup 133/Xe. Material samples were placed at selected distances from the detector phantom, both individually and in various combinations. Pulse-height spectra resulting from beta radiations were converted to relative D.E. rates at a 70-micron tissue depth. The relative D.E. rates were reduced from values with no clothing cover by as little as 45% when placing a single thin nylon cloth 1 cm from the phantom, to 94% for a T-shirt material plus wool material plus denim placed 1/2, 1 and 3 cm, respectively, from the phantom. The results indicate that even loosely fitting clothing can have an important effect on reducing the D.E. rate. Close-fitting clothing appears to provide better protection.

  16. A method for estimating (41)Ar, (85)(,88)Kr and (131m,133)Xe doses to non-human biota.

    PubMed

    Vives I Batlle, J; Jones, S R; Copplestone, D

    2015-06-01

    A method is presented for estimating (41)Ar, (85,88)Kr and (131m,133)Xe dose rates to terrestrial wildlife without having to resort to comparisons with analogue radionuclides. The approach can be used to calculate the dose rates arising from external exposures to given ambient air concentrations of these isotopes. Dose conversion coefficient (DCC) values for a range of representative organisms are calculated, using a Monte Carlo approach to generate absorbed fractions based on representing animals as reference ellipsoid geometries. Plume immersion is the main component of the total DCC. DCC values calculated for a human-sized organism are compared with human dose conversion factors from ICRP Publication 119, demonstrating the consistency of the biota approach with that for humans. An example of application is provided for hypothetical nuclear power plant atmospheric discharges with associated exposures to birds and insects. In this example, the dose rates appear to be dominated by (133)Xe and (88)Kr, respectively. The biota considered would be protected from the effects of noble gas radiation from a population protection perspective.

  17. A method for estimating (41)Ar, (85)(,88)Kr and (131m,133)Xe doses to non-human biota.

    PubMed

    Vives I Batlle, J; Jones, S R; Copplestone, D

    2015-06-01

    A method is presented for estimating (41)Ar, (85,88)Kr and (131m,133)Xe dose rates to terrestrial wildlife without having to resort to comparisons with analogue radionuclides. The approach can be used to calculate the dose rates arising from external exposures to given ambient air concentrations of these isotopes. Dose conversion coefficient (DCC) values for a range of representative organisms are calculated, using a Monte Carlo approach to generate absorbed fractions based on representing animals as reference ellipsoid geometries. Plume immersion is the main component of the total DCC. DCC values calculated for a human-sized organism are compared with human dose conversion factors from ICRP Publication 119, demonstrating the consistency of the biota approach with that for humans. An example of application is provided for hypothetical nuclear power plant atmospheric discharges with associated exposures to birds and insects. In this example, the dose rates appear to be dominated by (133)Xe and (88)Kr, respectively. The biota considered would be protected from the effects of noble gas radiation from a population protection perspective. PMID:25863225

  18. A Novel Physiological Investigation of the Functional Residual Capacity by the Bias Flow Nitrogen Washout Technique in Infants

    PubMed Central

    Morris, Mohy G.

    2011-01-01

    Summary The dynamic functional residual capacity (FRCdyn), the lung volume most routinely measured in infants, is an unreliable volume landmark. In addition to the FRCdyn, we measured the (passive) static FRC (FRCst) by inducing a brief post-hyperventilation apnea (PHA) in 33 healthy infants aged 7.4–127.2 weeks. A commercial system for nitrogen (N2) washout to measure FRC, and a custom made system to monitor and record flow and airwayopening pressure signals in real-time were used in unison. Infants were manually hyperventilated to induce a PHA. After the last passive expiration, FRCst was estimated by measuring the volume of N2 expired after end-passive expiratory switching of the inspired gas from room air to 100% oxygen during the post-expiratory apneic pause. Repeatable intrasubject FRCst and FRCdyn measurements overlapped in most infants including the younger ones (P = 0.2839). Mean (95% confidence interval [CI]) FRCst was 21.1 (20.0–22.3), and error-corrected FRCdyn was 21.4 (20.4–22.4) ml/kg. Mean (washout time [t]) tFRCst was longer than tFRCdyn 60 sec (95% CI 55–65) versus 47 sec (95% CI 43–51) (P<0.0001). The FRC and washout time were dependent on body length, weight and age. We conclude that the FRCst is not different from the FRCdyn in infants. The FRCst is a reliable volume landmark because the PHA stabilizes the end-expiratory level by potentially abolishing the sedated infant’s breathing strategies. The FRCst lacks potential sources of errors and disadvantages associated with measuring the FRCdyn. The findings cast significant doubt on the traditional physiology of air trapping in healthy infants’ lungs. PMID:19499588

  19. Computation and Analysis of the Global Distribution of the Radioxenon Isotope 133Xe based on Emissions from Nuclear Power Plants and Radioisotope Production Facilities and its Relevance for the Verification of the Nuclear-Test-Ban Treaty

    NASA Astrophysics Data System (ADS)

    Wotawa, Gerhard; Becker, Andreas; Kalinowski, Martin; Saey, Paul; Tuma, Matthias; Zähringer, Matthias

    2010-05-01

    Monitoring of radioactive noble gases, in particular xenon isotopes, is a crucial element of the verification of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). The capability of the noble gas network, which is currently under construction, to detect signals from a nuclear explosion critically depends on the background created by other sources. Therefore, the global distribution of these isotopes based on emissions and transport patterns needs to be understood. A significant xenon background exists in the reactor regions of North America, Europe and Asia. An emission inventory of the four relevant xenon isotopes has recently been created, which specifies source terms for each power plant. As the major emitters of xenon isotopes worldwide, a few medical radioisotope production facilities have been recently identified, in particular the facilities in Chalk River (Canada), Fleurus (Belgium), Pelindaba (South Africa) and Petten (Netherlands). Emissions from these sites are expected to exceed those of the other sources by orders of magnitude. In this study, emphasis is put on 133Xe, which is the most prevalent xenon isotope. First, based on the emissions known, the resulting 133Xe concentration levels at all noble gas stations of the final CTBT verification network were calculated and found to be consistent with observations. Second, it turned out that emissions from the radioisotope facilities can explain a number of observed peaks, meaning that atmospheric transport modelling is an important tool for the categorization of measurements. Third, it became evident that Nuclear Power Plant emissions are more difficult to treat in the models, since their temporal variation is high and not generally reported. Fourth, there are indications that the assumed annual emissions may be underestimated by factors of two to ten, while the general emission patterns seem to be well understood. Finally, it became evident that 133Xe sources mainly influence the sensitivity of the

  20. An evaluation of the external radiation exposure dosimetry and calculation of maximum permissible concentration values for airborne materials containing 18F, 15O, 13N, 11C and 133Xe.

    PubMed

    Piltingsrud, H V; Gels, G L

    1985-11-01

    To better understand the dose equivalent (D.E.) rates produced by airborne releases of gaseous positron-emitting radionuclides under various conditions of cloud size, a study of the external radiation exposure dosimetry of these radionuclides, as well as negatron, gamma and x-ray emitting 133Xe, was undertaken. This included a calculation of the contributions to D.E. as a function of cloud radii, at tissue depths of 0.07 mm (skin), 3 mm (lens of eye) and 10 mm (whole body) from both the particulate and photon radiations emitted by these radionuclides. Estimates of maximum permissible concentration (MPC) values were also calculated based on the calculated D.E. rates and current regulations for personnel radiation protection (CFR84). Three continuous air monitors, designed for use with 133Xe, were evaluated for applications in monitoring air concentrations of the selected positron emitters. The results indicate that for a given radionuclide and for a cloud greater than a certain radius, personnel radiation dosimeters must respond acceptably to only the photon radiations emitted by the radionuclide to provide acceptable personnel dosimetry. For clouds under that radius, personnel radiation dosimeters must also respond acceptably to the positron or negatron radiations to provide acceptable personnel dosimetry. It was found that two out of the three air concentration monitors may be useful for monitoring air concentrations of the selected positron emitters.

  1. Effect of hydration on nitrogen washout in human subjects

    NASA Technical Reports Server (NTRS)

    Waligora, J.; Horrigan, D. J., Jr.; Conkin, J.

    1983-01-01

    Five subjects were tested to assess the influence of drinking hypotonic water (distilled water) on whole body tissue nitrogen washout. During the test, the subjects breathed aviators' oxygen for three hours. Each subject performed two baseline nitrogen washouts in a two-week period. The third washout, in the third week, was done under a transient hydrated condition. This was accomplished by having the subjects drink 1.5 liters of hypotonic water 30 minutes before the washout. Five-minute plots of tissue nitrogen removal from the three separate washouts were analyzed to ascertain if the hydration technique had any effect. Our results clearly indicate that the hydration technique did not alter the tissue nitrogen washout characteristics to any degree over three hours. An increase in tissue nitrogen washout under a transient hydrated condition using hypotonic fluid was not demonstrated to be the mechanism responsible for the reported benefit of this technique in preventing Type I altitude decompression pain in man.

  2. Lung function measurement with multiple-breath-helium washout system.

    PubMed

    Wang, J-Y; Suddards, M E; Mellor, C J; Owers-Bradley, J R

    2013-04-01

    Multiple-breath-washout (MBW) measurements are regarded as a sensitive technique which can reflect the ventilation inhomogeneity of respiratory airways. Typically nitrogen is used as the tracer gas and is washed out by pure oxygen in multiple-breath-nitrogen washout (MBNW) tests. In this study, instead of using nitrogen, (4)He is used as the tracer gas with smaller gas density which may be able to reach deeper into our lungs in a given time and the helium washout results may be more sensitive to the ventilation inhomogeneity in small airways. A multiple-breath-helium-washout (MBHW) system developed for the lung function study is also presented. Quartz tuning forks with a resonance frequency of 32,768Hz have been used for detecting the change of the respiratory gas density. The resonance frequency of the quartz tuning fork decreases linearly with increasing density of the surrounding gas. Knowing the CO2 concentration from the infrared carbon dioxide detector, the helium concentration can be determined. Results from 14 volunteers (3 mild asthmatics, 4 tobacco smokers, 1 with asthma history, 1 with COPD history, 5 normal) have shown that mild asthmatics have higher ventilation inhomogeneity in either conducting or acinar airways (or both). A feature has been found in washout curve of single breaths from 4 tobacco smokers with different length of smoking history which may indicate the early stage of respiratory ventilation inhomogeneity in acinar airways.

  3. Cerebral blood flow studied by Xenon-133 inhalation technique in parkinsonism: loss of hyperfrontal pattern

    SciTech Connect

    Bes, A.; Gueell, A.; Fabre, N.; Dupui, P.; Victor, G.; Geraud, G.

    1983-03-01

    Cerebral blood flow (grey matter flow) in parkinsonism requires further investigation. The noninvasive method of /sup 133/Xe inhalation permits study of larger numbers of subjects than previously used invasive techniques such as the intracarotid /sup 133/Xe injection method. Measurements were made in this laboratory in 30 subjects having Parkinson's disease. Mean hemispheric blood flow (F1) values were 70.4 +/- 9.3 ml/100 g/min, compared to 76.3 for a group of age-matched normal subjects, which is a decrease of -7.8%. The most striking difference was the loss of the hyperfrontal distribution in parkinsonism. The prefrontal F1 values were only 1.8% greater than the hemisphere grey matter flow, compared with 8.5% in controls of a similar age group.

  4. Measurement of functional residual capacity by sulfur hexafluoride washout.

    PubMed

    Jonmarker, C; Jansson, L; Jonson, B; Larsson, A; Werner, O

    1985-07-01

    Measurement of functional residual capacity (FRC) by the open-circuit multiple breath tracer gas washout technique is an established method. A system based upon washout of sulfur hexafluoride (SF6) during mechanical ventilation is described. The central unit in the system is a sensitive and rapid-response infrared SF6 analyzer. SF6 is washed in until the alveolar concentration of SF6 is 0.5%, a concentration so low that the supply of other gases is hardly influenced. During washout, the flow of SF6 from the lungs is calculated by a computer every 10 ms from signals representing expiratory flow and SF6 concentration. The total volume of SF6, washed out, is calculated by integration of SF6 flow. Since the alveolar concentration at the end of washin is known, the lung volume may be obtained. The measurement procedure is highly automated and the result is presented by the computer immediately after washout. Accurate and reproducible results in model lung tests were obtained during air and N2O/O2 ventilation. Comparison with body plethysmography (FRCBOX) in eight sitting healthy subjects gave the following: FRCSF6 = 7 ml + 0.98 X FRCBOX, r = 0.99. Comparison with nitrogen washout (FRCN2) in five postoperative patients gave the following: FRCSF6 = 59 ml + 0.97 X FRCN2, r = 0.97. FRCSF6 during N2O/O2 ventilation was the same as during air/O2 ventilation in a group of paralyzed patients. The measurement system has not been tested in patients with obstructive lung disease.

  5. HTO washout model: on the relationship between exchange rate and washout coefficient

    SciTech Connect

    Golubev, A.; Balashov, Y.; Mavrin, S.; Golubeva, V.; Galeriu, D.

    2015-03-15

    Washout coefficient Λ is widely used as a parameter in washout models. These models describes overall HTO washout with rain by a first-order kinetic equation, while washout coefficient Λ depends on the type of rain event and rain intensity and empirical parameters a, b. The washout coefficient is a macroscopic parameter and we have considered in this paper its relationship with a microscopic rate K of HTO isotopic exchange in atmospheric humidity and drops of rainwater. We have shown that the empirical parameters a, b can be represented through the rain event characteristics using the relationships of molecular impact rate, rain intensity and specific rain water content while washout coefficient Λ can be represented through the exchange rate K, rain intensity, raindrop diameter and terminal raindrop velocity.

  6. Continuous distributions of specific ventilation recovered from inert gas washout

    NASA Technical Reports Server (NTRS)

    Lewis, S. M.; Evans, J. W.; Jalowayski, A. A.

    1978-01-01

    A new technique is described for recovering continuous distributions of ventilation as a function of tidal ventilation/volume ratio from the nitrogen washout. The analysis yields a continuous distribution of ventilation as a function of tidal ventilation/volume ratio represented as fractional ventilations of 50 compartments plus dead space. The procedure was verified by recovering known distributions from data to which noise had been added. Using an apparatus to control the subject's tidal volume and FRC, mixed expired N2 data gave the following results: (a) the distributions of young, normal subjects were narrow and unimodal; (b) those of subjects over age 40 were broader with more poorly ventilated units; (c) patients with pulmonary disease of all descriptions showed enlarged dead space; (d) patients with cystic fibrosis showed multimodal distributions with the bulk of the ventilation going to overventilated units; and (e) patients with obstructive lung disease fell into several classes, three of which are illustrated.

  7. Inert gas washout: theoretical background and clinical utility in respiratory disease.

    PubMed

    Robinson, Paul D; Goldman, Michael D; Gustafsson, Per M

    2009-01-01

    Inert gas washout was first described more than 60 years ago and 2 principal tests have been developed from it: the single breath and multiple breath washout (MBW) techniques. The invention of fast responding gas analysers almost 60 years ago and small computers 30 years later have facilitated breath-by-breath analysis and the development of sophisticated analysis techniques. It is now possible to detect not only the degree of pulmonary ventilation inhomogeneity, but also to gain important insight into the location of the underlying disease process. While single breath washout requires a full vital capacity effort, tidal breathing during the multiple breath test requires minimal co-operation and co-ordination, and is feasible in subjects of all ages. Available MBW normative data from parameters, such as the lung clearance index, appears to vary minimally with age, making MBW particularly useful to follow children longitudinally. Multiple breath inert gas washout has demonstrated improved sensitivity, in comparison to spirometry, in the early detection of a number of important disease processes, including cystic fibrosis. Despite this, these important techniques remain under-utilised in the clinical setting and there is a lack of commercially available devices currently available. The recent resurgence of research in this area has produced a large number of important studies and a pronounced international interest has developed in these techniques. This review article will provide an overview of the theoretical background of inert gas washout and analysis indices, review important physiological and clinical insights gained from research to date (as well as from our own experience) to illustrate its utility, and outline the challenges that lie ahead in incorporating these techniques into the mainstream clinical setting. PMID:19521061

  8. Washout after lobectomy: is water more effective than normal saline in preventing local recurrence?

    PubMed

    Tsakok, Teresa; Tsakok, Maria; Damji, Charlene; Watson, Robert

    2012-02-01

    A best evidence topic in thoracic surgery was written according to a structured protocol. The question addressed was: 'is water washout more effective than normal saline washout after lobectomy in preventing local recurrence?' Altogether more than 48 papers were found using the reported search, of which nine represented the best evidence to answer the clinical question. The authors, journal, date, country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Tumour cell 'spillage' after cancer resection is linked to a worse prognosis, so washout to minimize contamination is an established surgical technique. While the mechanical effects of lavage are well validated, the differential cytocidal effects of water versus saline as irrigation fluids are not. There are currently no studies addressing this issue in the thoracic surgery setting, after lung cancer lobectomy. However, the majority of relevant papers describe the use of basic in vitro methods and animal models to produce data that can conceivably be extrapolated to the clinical question in hand. The number of studies is small, and some have technical limitations. While two of the better-designed experiments suggest that water exerts a superior cytocidal effect on tumour cells, data from other studies are somewhat unimpressive, with two studies reporting that water washout controls tumour growth to a lesser extent than saline. This, together with the complete paucity of clinical trials on the subject, leads us to conclude that water is unlikely to represent a superior irrigation fluid in lung cancer patients after lobectomy. PMID:22159256

  9. Strong washout approximation to resonant leptogenesis

    SciTech Connect

    Garbrecht, Björn; Gautier, Florian; Klaric, Juraj E-mail: florian.gautier@tum.de

    2014-09-01

    We show that the effective decay asymmetry for resonant Leptogenesis in the strong washout regime with two sterile neutrinos and a single active flavour can in wide regions of parameter space be approximated by its late-time limit ε=Xsin(2φ)/(X{sup 2}+sin{sup 2}φ), where X=8πΔ/(|Y{sub 1}|{sup 2}+|Y{sub 2}|{sup 2}), Δ=4(M{sub 1}-M{sub 2})/(M{sub 1}+M{sub 2}), φ=arg(Y{sub 2}/Y{sub 1}), and M{sub 1,2}, Y{sub 1,2} are the masses and Yukawa couplings of the sterile neutrinos. This approximation in particular extends to parametric regions where |Y{sub 1,2}|{sup 2}>> Δ, i.e. where the width dominates the mass splitting. We generalise the formula for the effective decay asymmetry to the case of several flavours of active leptons and demonstrate how this quantity can be used to calculate the lepton asymmetry for phenomenological scenarios that are in agreement with the observed neutrino oscillations. We establish analytic criteria for the validity of the late-time approximation for the decay asymmetry and compare these with numerical results that are obtained by solving for the mixing and the oscillations of the sterile neutrinos. For phenomenologically viable models with two sterile neutrinos, we find that the flavoured effective late-time decay asymmetry can be applied throughout parameter space.

  10. The field experiments on the HTO washout from the atmosphere

    SciTech Connect

    Golubev, A.V.; Mavrin, S.V.; Golubeva, V.N.; Stengach, A.V.; Balashov, Y.S.; Kovalenko, V.P.; Solomatin, I.I.

    2015-03-15

    HTO (tritiated water) wash-out from the atmosphere is one of the key processes governing the HTO transport from the atmosphere into soil and plants. Experimental studies of the HTO interaction with water drops were carried out both in laboratories and in the field. In the course of experiments, the following rain characteristics were recorded: rain intensity, size distribution of drops, and falling velocities and their dependence on drop diameter. A laser optical device was designed and used to measure the distribution of the drop radius and velocities during the period of experiment. The tritium source was placed at a height of 30 m. Rainwater samples were collected in plastic bottles and their HTO activity was determined by liquid scintillation techniques. The data obtained for the experimental values of the scavenging rate are within the range from 4.12*10{sup -5} to 1.57*10{sup -4} s{sup -1} and correspond to the precipitation intensity from 0.3 to 1.26 mm/hour. These results are in sufficiently good agreement with the results of earlier papers.

  11. Wash-out in N2-dominated leptogenesis

    NASA Astrophysics Data System (ADS)

    Hahn-Woernle, F.

    2010-08-01

    We study the wash-out of a cosmological baryon asymmetry produced via leptogenesis by subsequent interactions. Therefore we focus on a scenario in which a lepton asymmetry is established in the out-of-equilibrium decays of the next-to-lightest right-handed neutrino. We apply the full classical Boltzmann equations without the assumption of kinetic equilibrium and including all quantum statistical factors to calculate the wash-out of the lepton asymmetry by interactions of the lightest right-handed state. We include scattering processes with top quarks in our analysis. This is of particular interest since the wash-out is enhanced by scatterings and the use of mode equations with quantum statistical distribution functions. In this way we provide a restriction on the parameter space for this scenario.

  12. Ventilatory inhomogeneity determined from multiple-breath washouts during sustained microgravity on Spacelab SLS-1

    NASA Technical Reports Server (NTRS)

    Prisk, G. Kim; Guy, Harold J. B.; Elliott, Ann R.; Paiva, Manuel; West, John B.

    1995-01-01

    We used multiple-breath N2 washouts (MBNW) to study the homogeneity of ventilation in four normal humans (mean age 42.5 yr) before, during, and after 9 days of exposure to microgravity on Spacelab Life Sciences-1. Subjects performed 20-breath MBNW at tidal volumes of approximately 700 ml and 12-breath MBNW at tidal volumes of approximately 1,250 ml. Six indexes of ventilatory inhomogeneity were derived from data from (1) distribution of specific ventilation (SV) from mixed-expired and (2) end-tidal N2, (3) change of slope of N2 washout (semilog plot) with time, (4) change of slope of normalized phase III of successive breaths, (5) anatomic lead dead space, and (6) Bohr dead space. Significant ventilatory inhomogeneity was seen in the standing position at normal gravity (1 G). When we compared standing 1 G with microgravity, the distributions of SV became slightly narrower, but the difference was not significant. Also, there were no significant changes in the change of slope of the N2 washout, change of normalized phase III slopes, or the anatomic and Bohr dead spaces. By contrast, transition from the standing to supine position in 1 G resulted in significantly broader distributions of SV and significantly greater changes in the changes in slope of the N2 washouts, indicating more ventilatory inhomogeneity in that posture. Thus these techniques can detect relatively small changes in ventilatory inhomogeneity. We conclude that the primary determinants of ventilatory inhomogeneity during tidal breathing in the upright posture are not gravitational in origin.

  13. Managing cytotoxic chemotherapy extravasation: use of saline washout.

    PubMed

    Harrold, Karen

    Florence Nightingale Foundation scholar Karen Harrold received funding to support her PhD exploring the patient experience of saline washout as a management strategy for chemotherapy extravasation. She discusses the focus of her thesis, the completion of phase one and looks ahead to phase two. PMID:25904536

  14. Space Suit CO2 Washout During Intravehicular Activity

    NASA Technical Reports Server (NTRS)

    Augustine, Phillip M.; Navarro, Moses; Conger, Bruce; Sargusingh, Miriam M.

    2010-01-01

    Space suit carbon dioxide (CO2) washout refers to the removal of CO2 gas from the oral-nasal area of a suited astronaut's (or crewmember's) helmet using the suit's ventilation system. Inadequate washout of gases can result in diminished mental/cognitive abilities as well as headaches and light headedness. In addition to general discomfort, these ailments can impair an astronaut s ability to perform mission-critical tasks ranging from flying the space vehicle to performing lunar extravehicular activities (EVAs). During design development for NASA s Constellation Program (CxP), conflicting requirements arose between the volume of air flow that the new Orion manned space vehicle is allocated to provide to the suited crewmember and the amount of air required to achieve CO2 washout in a space suit. Historically, space suits receive 6.0 actual cubic feet per minute (acfm) of air flow, which has adequately washed out CO2 for EVAs. For CxP, the Orion vehicle will provide 4.5 acfm of air flow to the suit. A group of subject matter experts (SM Es) among the EVA Systems community came to an early consensus that 4.5 acfm may be acceptable for low metabolic rate activities. However, this value appears very risky for high metabolic rates, hence the need for further analysis and testing. An analysis was performed to validate the 4.5 acfm value and to determine if adequate CO2 washout can be achieved with the new suit helmet design concepts. The analysis included computational fluid dynamic (CFD) modeling cases, which modeled the air flow and breathing characteristics of a human wearing suit helmets. Helmet testing was performed at the National Institute of Occupational Safety and Health (NIOSH) in Pittsburgh, Pennsylvania, to provide a gross-level validation of the CFD models. Although there was not a direct data correlation between the helmet testing and the CFD modeling, the testing data showed trends that are very similar to the CFD modeling. Overall, the analysis yielded

  15. Washout rate in rat brain irradiated by a 11C beam after acetazolamide loading using a small single-ring OpenPET prototype

    NASA Astrophysics Data System (ADS)

    Hirano, Yoshiyuki; Takuwa, Hiroyuki; Yoshida, Eiji; Nishikido, Fumihiko; Nakajima, Yasunori; Wakizaka, Hidekatsu; Yamaya, Taiga

    2016-03-01

    In dose verification techniques of particle therapies based on in-beam positron emission tomography (PET), the causes of washout of positron emitters by physiological effects should be clarified to correct washout for accurate verification. As well, the quantitative washout rate has a potential usefulness as a diagnostic index which should be explored. Therefore, we measured washout rates of rat brain after vasodilator acetazolamide loading to investigate the possible effects of blood flow on washout. Six rat brains were irradiated by a radioisotope 11C beam and time activity curves on the whole brains were obtained with a small single-ring OpenPET prototype. Then, washout rates were calculated with the Mizuno model, where two washout rates (k 2m and k 2s ) were assumed, and a two-compartment model including efflux from tissue to blood (k 2) and influx (k 3) and efflux (k 4) between the two tissue compartments. Before the irradiations, we used laser-Doppler flowmetry to confirm that acetazolamide increased cerebral blood flow (CBF) of a rat. We compared means of k 2m , k 2s and k 2, k 3 and k 4 without acetazolamide loading (Rest) and with acetazolamide loading (ACZ). For all k values, ACZ values were lower than Rest values. In other words, though CBF increased, washout rates were decreased. This may be attributed to the implanted 11C reacting to form 11CO2. Because acetazolamide increased the concentration of CO2 in brain, suppressed diffusion of 11CO2 and decomposition of 11CO2 into ions were prevented.

  16. Inclusion of a three-dimensional washout coefficient in ADPIC

    SciTech Connect

    Naeslund, E.; Holmstroem, H.

    1993-05-01

    In ADPIC, the deposition emerging from washout has thus far been modelled rather crudely, since the only option has been to turn the rain on and off at different times. This kind of modelling is particularly unsatisfactory when ADPIC is used to model continuous releases over long periods of time. The assumption of simultaneous rain throughout such a large plume is simply not true. In this report a modified version of ADPIC with a three-dimensional (3-D) washout coefficient is presented. The effect of space variable precipitation is examined via two separate releases that are simulated for a period of 48 hours: one continuous {open_quote}Chernobyl-like source{close_quote} release and one instantaneous {open_quote}nuclear explosion-like{close_quote}. Simulations with both the new and old formulation are made and the resulting deposition patterns are compared.

  17. Wash-out of ambient air contaminations for breath measurements.

    PubMed

    Maurer, F; Wolf, A; Fink, T; Rittershofer, B; Heim, N; Volk, T; Baumbach, J I; Kreuer, S

    2014-06-01

    In breath analysis, ambient air contaminations are ubiquitous and difficult to eliminate. This study was designed to investigate the reduction of ambient air background by a lung wash-out with synthetic air. The reduction of the initial ambient air volatile organic compound (VOC) intensity was investigated in the breath of 20 volunteers inhaling synthetic air via a sealed full face mask in comparison to inhaling ambient air. Over a period of 30 minutes, breath analysis was conducted using ion mobility spectrometry coupled to a multi-capillary column. A total of 68 VOCs were identified for inhaling ambient air or inhaling synthetic air. By treatment with synthetic air, 39 VOCs decreased in intensity, whereas 29 increased in comparison to inhaling ambient air. In total, seven VOCs were significantly reduced (P-value < 0.05). A complete wash-out of VOCs in this setting was not observed, whereby a statistically significant reduction up to 65% as for terpinolene was achieved. Our setting successfully demonstrated a reduction of ambient air contaminations from the airways by a lung wash-out with synthetic air.

  18. Kubo relations and radiative corrections for lepton number washout

    SciTech Connect

    Bödeker, Dietrich; Laine, M. E-mail: laine@itp.unibe.ch

    2014-05-01

    The rates for lepton number washout in extensions of the Standard Model containing right-handed neutrinos are key ingredients in scenarios for baryogenesis through leptogenesis. We relate these rates to real-time correlation functions at finite temperature, without making use of any particle approximations. The relations are valid to quadratic order in neutrino Yukawa couplings and to all orders in Standard Model couplings. They take into account all spectator processes, and apply both in the symmetric and in the Higgs phase of the electroweak theory. We use the relations to compute washout rates at next-to-leading order in g, where g denotes a Standard Model gauge or Yukawa coupling, both in the non-relativistic and in the relativistic regime. Even in the non-relativistic regime the parametrically dominant radiative corrections are only suppressed by a single power of g. In the non-relativistic regime radiative corrections increase the washout rate by a few percent at high temperatures, but they are of order unity around the weak scale and in the relativistic regime.

  19. A comparison of washout filters using a human dynamic orientation model. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Riedel, S. A.

    1977-01-01

    The Ormsby model of human dynamic orientation, a discrete time computer program, was used to provide a vestibular explanation for observed differences between two washout schemes. These washout schemes, a linear washout and a nonlinear washout, were subjectively evaluated. It was found that the linear washout presented false rate cues, causing pilots to rate the simulation fidelity of the linear scheme much lower than the nonlinear scheme. By inputting these motion histories into the Ormsby model, it was shown that the linear filter causes discontinuities in the pilot's perceived angular velocity, resulting in the sensation of an anomalous rate cue. This phenomenon does not occur with the use of the nonlinear filter.

  20. [The washout in emergency surgery of the colon. A technical note].

    PubMed

    Peppas, C; D'Ambrosio, R; Rapicano, G; De Rosa, G; Romagnuolo, G; Martino, R; Martino, A

    1996-12-01

    The authors report their experience in the treatment of 179 cases of colonic neoplasm between January 1985 and August 1992. Particularly, they emphasize the advantages of one-stage colectomy with anastomosis because of an obstructing carcinoma of the left colon, used on 41 cases. This treatment can be practicable by using the intraoperative "wash-out" technique. The one-stage colectomy with anastomosis can be advisable because the long survival can be compared to that deriving from the non obstructing carcinoma. Moreover this technique offers several advantages such as the one-stage treatment, the absence of colostomy, the improvement of the cost-benefit relationship, etc. On 41 cases treated by this technique, the authors lament only one decease caused by a total dehiscence of the anastomosis, notwithstanding reintervention. Moreover, 9 cases of partial dehiscence were treated by NPT (Total Parenteral Nutrition) except one which demanded a reintervention. PMID:9064569

  1. Multiple Breath Nitrogen Washout: A Feasible Alternative to Mass Spectrometry

    PubMed Central

    Jensen, Renee; Stanojevic, Sanja; Gibney, Karyn; Salazar, Juliana Giraldo; Gustafsson, Per; Subbarao, Padmaja; Ratjen, Felix

    2013-01-01

    Background The lung clearance index (LCI), measured by multiple breath washout (MBW), reflects global ventilation inhomogeneity and is a sensitive marker of early cystic fibrosis (CF) lung disease. Current evidence is based on a customized mass spectrometry system that uses sulfur hexafluoride (SF6) as a tracer gas, which is not widely available. Nitrogen (N2) washout may be better suited for clinical use and multi-center trials. Objective To compare the results obtained from a N2 washout system to those generated by the SF6 based system in healthy children and children with CF. Methods Children with CF were recruited from outpatient clinics; healthy children were recruited from the Research4Kids online portal. Participants performed MBWSF6 (Amis 2000, Innovision, Denmark) and MBWN2 (ExhalyzerD, EcoMedics, Switzerland) in triplicate, in random order on the same day. Agreement between systems was assessed by Bland-Altman plot. Results Sixty-two healthy and 61 children with CF completed measurements on both systems. In health there was good agreement between systems (limits of agreement −0.7 to 1.9); on average N2 produced higher values of LCI (mean difference 0.58 (95% CI 0.42 to 0.74)). In CF the difference between systems was double that in health with a clear bias towards disproportionately higher LCIN2 compared to LCISF6 at higher mean values of LCI. Conclusion LCIN2 and LCISF6 have similar discriminative power and intra-session repeatability but are not interchangeable. MBWN2 offers a valid new tool to investigate early obstructive lung disease in CF, but requires independent normative values. PMID:23457632

  2. Ventilation Inception and Washout, Scaling, and Effects on Hydrodynamic Performance of a Surface Piercing Strut

    NASA Astrophysics Data System (ADS)

    Harwood, Casey; Young, Yin Lu; Ceccio, Steven

    2014-11-01

    High-lift devices that operate at or near a fluid free surface (such as surface-piercing or shallowly-submerged propellers and hydrofoils) are prone to a multiphase flow phenomenon called ventilation, wherein non-condensable gas is entrained in the low-pressure flow, forming a cavity around the body and dramatically altering the global hydrodynamic forces. Experiments are being conducted at the University of Michigan's towing tank using a canonical surface-piercing strut to investigate atmospheric ventilation. The goals of the work are (i) to gain an understanding of the dominant physics in fully wetted, partially ventilated, and fully ventilated flow regimes, (ii) to quantify the effects of governing dimensionless parameters on the transition between flow regimes, and (iii) to develop scaling relations for the transition between flow regimes. Using theoretical arguments and flow visualization techniques, new criteria are developed for classifying flow regimes and transition mechanisms. Unsteady transition mechanisms are described and mapped as functions of the governing non-dimensional parameters. A theoretical scaling relationship is developed for ventilation washout, which is shown to adequately capture the experimentally-observed washout boundary. This material is based upon work supported by the National Science Foundation Graduate Student Research Fellowship under Grant No. DGE 1256260. Support also comes from the Naval Engineering Education Center (Award No. N65540-10-C-003).

  3. Determination of washout performance of various monochrome displays under simulated flight ambient and solar lighting conditions

    NASA Technical Reports Server (NTRS)

    Batson, Vernon M.; Robertson, James B.; Parrish, Russell V.

    1990-01-01

    The aircraft cockpit ambient lighting simulation system (ACALSS) has been developed to study display readability and associated pilot/vehicle performance effects in a part-task simulator cockpit. In the study reported here, the ACALSS was used to determine the illumination levels at which subjects lose the ability to maintain aircraft states when using three display technologies as display media for primary flight displays: a standard monochrome EL (electroluminescent) flat-panel, a laboratory-class monochrome CRT, and an enhanced-brightness EL flat-panel. The multivariate statistical technique of modified profile analysis was used to test for performance differences between display devices as functions of illumination levels. The standard monochrome EL flat-panel display began to washout after the 2500 foot-candle level of illumination. The monochrome CRT began to washout after the 5500 foot-candle level of illumination. No performance decrements by increased illumination up to the 12,000 foot-candle level were found for the enhanced-brightness EL flat-panel display. What was not anticipated was that half the subjects would subjectively prefer the CRT over the enhanced-brightness EL, even though their performance errors would have indicated the opposite.

  4. Fast washout of thallium-201 from area of myocardial infarction: possible artifact of background subtraction

    SciTech Connect

    Brown, K.A.; Benoit, L.; Clements, J.P.; Wackers, F.J.

    1987-06-01

    A recent report described a pattern of reverse redistribution on poststreptokinase /sup 201/Tl studies which was believed to be due to rapid washout of /sup 201/Tl from the infarct area related to reperfusion of the infarct vessel. We have also observed the phenomenon of rapid washout of /sup 201/Tl from the area of infarction in the absence of thrombolytic therapy. This study was undertaken to test the hypothesis that rapid washout of /sup 201/Tl from an area of infarction is an artifact of background subtraction usually employed in analysis of washout. A total of 61 patients with previous myocardial infarction who underwent cardiac catheterization and exercise /sup 201/Tl imaging were examined. Thallium-201 images were analyzed using a validated quantitative method employing interpolative background correction. Abnormally increased /sup 201/Tl washout was noted in 11 infarct segments in 10 (18%) patients. Infarct segments with rapid washout had significantly less initial uptake, and more severe associated wall motion abnormalities than infarct segments with normal washout. When quantitative analysis was repeated without background subtraction, no segments with rapid washout were observed. A phantom model was constructed to further test our hypothesis. The frequency of observed rapid washout was directly related to the severity of the initial defect and was entirely dependent upon utilizing background correction during the quantitative analysis. Our study suggests that rapid washout of /sup 201/Tl in an area of previous infarction reflects an artifact of background subtraction involved with standard quantitative analysis.

  5. Efficacy of contrast-enhanced ultrasound washout rate in predicting hepatocellular carcinoma differentiation.

    PubMed

    Feng, Yan; Qin, Xia-Chuan; Luo, Yan; Li, Yong-Zhong; Zhou, Xiang

    2015-06-01

    The aim of this retrospective study was to evaluate the efficacy of contrast-enhanced ultrasound (CEUS) washout rate in predicting hepatocellular carcinoma (HCC) differentiation. Two hundred seventy-one patients underwent liver resection for HCC between April 2008 and December 2012 after being examined by CEUS using the contrast agent SonoVue with a low mechanical index (<0.1) in a routine procedure. Contrast agent washout rates obtained from video images were divided into four categories from slow to fast: WR1 = no washout in all phases (slowest); WR2 = washout after 120 s from contrast injection (late-phase washout); WR3 = washout between 41 and 120 s from contrast injection (portal venous washout); WR4 = washout before 40 s from contrast injection (fastest washout rate). HCC nodules were graded as well, moderately and poorly differentiated. Spearman rank correlation and χ(2)-tests were used to assess group relationships and differences. Receiver operating characteristic curve analysis was used to determine the diagnostic predictive value of CEUS. Among the 271 patients, 18 (6.6%) had well differentiated, 150 (55.4%) had moderately differentiated and 103 (38.0%) had poorly differentiated HCC. Statistical tests indicated that washout rate was significantly correlated with tumor differentiation (p < 0.05), and the poorly differentiated HCCs had earlier washout. At the cutoff point of WR4, CEUS based on washout rate performed poorly in distinguishing poorly differentiated from moderately and well-differentiated HCCs, with a sensitivity, specificity and accuracy (area under the curve) of 24%, 97% and 0.68, respectively. However, at the cutoff point of WR2, the sensitivity, specificity and accuracy of CEUS in differentiating well-differentiated HCC from other HCCs were significantly better: 98%, 78% and 0.96, respectively. Thus, CEUS washout rate may have a role in identifying patients with well-differentiated HCC.

  6. Phase V of the single-breath washout test

    NASA Technical Reports Server (NTRS)

    Nichol, G. M.; Michels, D. B.; Guy, H. J. B.

    1982-01-01

    A downward-deflecting phase V is often seen following the terminal rise (phase IV) in single-breath washout tests. To investigate the nature of phase V, experiments using simultaneous washouts of N2 and tracer boluses of Ar were performed on eight normal nonsmoking subjects aged 27-41 who exhibited a phase V. Phase V is found to occur in all subjects at expiratory flow rates between 0.1 and 2.0 l/sec shortly after expiration became flow limited. Volumes of both phases IV and V increase with increasing flow rate. The difference between the exhaled volumes at which flow became limited and phase V appeared is shown to be approximately equal to the anatomic dead space. Results support a model of lung emptying in a gravitational field in which flow limitation occurs first in the lower lung regions and then progresses toward the upper regions, causing phase IV. A decrease in the amount of flow from the upper relative to the lower regions after all regions have become flow limited then causes phase V.

  7. Peptide washout and permeability from glyceryl monooleate buccal delivery systems.

    PubMed

    Lee, Jaehwi; Kellaway, Ian W

    2002-10-01

    Simultaneous evaluation of the permeation and washout of a peptide from the mucoadhesive liquid crystalline phases of glyceryl monooleate (GMO) has been investigated using a donor compartment flow-through diffusion cell. [D-Ala2, D-Leu5]enkephalin (DADLE) was incorporated into the cubic and lamellar liquid crystalline phases of GMO and applied to excised porcine buccal mucosa mounted in the donor compartment flow-through cell. Phosphate-buffered saline pH 7.4 (PBS) was pumped across the upper surface of the liquid crystalline phases to mimic salivary flow. The steady-state fluxes of DADLE and GMO from the cubic phase were significantly greater than that from the lamellar phase (P < 0.01). There was no statistical difference between the amounts of DADLE and GMO washed out from the lamellar and cubic phases (P > 0.05). The donor compartment flow-through diffusion cell was found to be a useful tool to evaluate the impact of salivary washout on mucoadhesive oral mucosal delivery systems.

  8. Early detection of drillstring washouts reduces fishing jobs

    SciTech Connect

    Dudleson, B. ); Arnold, M.; McCann, D. )

    1990-10-01

    Rapid detection of unexpected drilling events requires continuous monitoring of drilling parameters. A major R and D program by a drilling contractor has led to the introduction of a computerized monitoring system on its offshore rigs. System includes advanced color graphics displays and new smart alarms to help both contractor and operator personnel detect and observe drilling events before they would normally be apparent with conventional rig instrumentation. This article describes a module of this monitoring system, which uses expert system technology to detect the earliest stages of drillstring washouts. Field results demonstrate the effectiveness of the smart alarm incorporated in the system. Early detection allows the driller to react before a twist-off results in expensive fishing operations.

  9. An Examination of "Wash-Out" and Workplace Conditions of Beginning Physical Education Teachers

    ERIC Educational Resources Information Center

    Blankenship, Bonnie Tjeerdsma; Colem, Margaret M.

    2009-01-01

    The purposes of this study were to: (1) determine the extent of wash-out in two beginning physical education teachers; and (2) determine the workplace conditions these novice teachers experienced that may have influenced the extent of wash-out for them. The interactive factors influencing workplace conditions for physical education teachers…

  10. A Systematic Approach to Multiple Breath Nitrogen Washout Test Quality

    PubMed Central

    Klingel, Michelle; Pizarro, Maria Ester; Hall, Graham L.; Ramsey, Kathryn; Foong, Rachel; Saunders, Clare; Robinson, Paul D.; Webster, Hailey; Hardaker, Kate; Kane, Mica; Ratjen, Felix

    2016-01-01

    Background Accurate estimates of multiple breath washout (MBW) outcomes require correct operation of the device, appropriate distraction of the subject to ensure they breathe in a manner representative of their relaxed tidal breathing pattern, and appropriate interpretation of the acquired data. Based on available recommendations for an acceptable MBW test, we aimed to develop a protocol to systematically evaluate MBW measurements based on these criteria. Methods 50 MBW test occasions were systematically reviewed for technical elements and whether the breathing pattern was representative of relaxed tidal breathing by an experienced MBW operator. The impact of qualitative and quantitative criteria on inter-observer agreement was assessed across eight MBW operators (n = 20 test occasions, compared using a Kappa statistic). Results Using qualitative criteria, 46/168 trials were rejected: 16.6% were technically unacceptable and 10.7% were excluded due to inappropriate breathing pattern. Reviewer agreement was good using qualitative criteria and further improved with quantitative criteria from (κ = 0.53–0.83%) to (κ 0.73–0.97%), but at the cost of exclusion of further test occasions in this retrospective data analysis. Conclusions The application of the systematic review improved inter-observer agreement but did not affect reported MBW outcomes. PMID:27304432

  11. Impact of Software Settings on Multiple-Breath Washout Outcomes

    PubMed Central

    Summermatter, Selina; Singer, Florian; Latzin, Philipp; Yammine, Sophie

    2015-01-01

    Background and Objectives Multiple-breath washout (MBW) is an attractive test to assess ventilation inhomogeneity, a marker of peripheral lung disease. Standardization of MBW is hampered as little data exists on possible measurement bias. We aimed to identify potential sources of measurement bias based on MBW software settings. Methods We used unprocessed data from nitrogen (N2) MBW (Exhalyzer D, Eco Medics AG) applied in 30 children aged 5–18 years: 10 with CF, 10 formerly preterm, and 10 healthy controls. This setup calculates the tracer gas N2 mainly from measured O2 and CO2concentrations. The following software settings for MBW signal processing were changed by at least 5 units or >10% in both directions or completely switched off: (i) environmental conditions, (ii) apparatus dead space, (iii) O2 and CO2 signal correction, and (iv) signal alignment (delay time). Primary outcome was the change in lung clearance index (LCI) compared to LCI calculated with the settings as recommended. A change in LCI exceeding 10% was considered relevant. Results Changes in both environmental and dead space settings resulted in uniform but modest LCI changes and exceeded >10% in only two measurements. Changes in signal alignment and O2 signal correction had the most relevant impact on LCI. Decrease of O2 delay time by 40 ms (7%) lead to a mean LCI increase of 12%, with >10% LCI change in 60% of the children. Increase of O2 delay time by 40 ms resulted in mean LCI decrease of 9% with LCI changing >10% in 43% of the children. Conclusions Accurate LCI results depend crucially on signal processing settings in MBW software. Especially correct signal delay times are possible sources of incorrect LCI measurements. Algorithms of signal processing and signal alignment should thus be optimized to avoid susceptibility of MBW measurements to this significant measurement bias. PMID:26167682

  12. Expiratory washout versus optimization of mechanical ventilation during permissive hypercapnia in patients with severe acute respiratory distress syndrome.

    PubMed

    Richecoeur, J; Lu, Q; Vieira, S R; Puybasset, L; Kalfon, P; Coriat, P; Rouby, J J

    1999-07-01

    The aim of this study was to compare three ventilatory techniques for reducing PaCO2 in patients with severe acute respiratory distress syndrome treated with permissive hypercapnia: (1) expiratory washout alone at a flow of 15 L/min, (2) optimized mechanical ventilation defined as an increase in the respiratory frequency to the maximal rate possible without development of intrinsic positive end- expiratory pressure (PEEP) combined with a reduction of the instrumental dead space, and (3) the combination of both methods. Tidal volume was set according to the pressure-volume curve in order to obtain an inspiratory plateau airway pressure equal to the upper inflection point minus 2 cm H2O after setting the PEEP at 2 cm H2O above the lower inflection point and was kept constant throughout the study. The three modalities were compared at the same inspiratory plateau airway pressure through an adjustment of the extrinsic PEEP. During conventional mechanical ventilation using a respiratory frequency of 18 breaths/min, respiratory acidosis (PaCO2 = 84 +/- 24 mm Hg and pH = 7.21 +/- 0.12) was observed. Expiratory washout and optimized mechanical ventilation (respiratory frequency of 30 +/- 4 breaths/min) had similar effects on CO2 elimination (DeltaPaCO2 = -28 +/- 11% versus -27 +/- 12%). A further decrease in PaCO2 was observed when both methods were combined (DeltaPaCO2 = -46 +/- 7%). Extrinsic PEEP had to be reduced by 5.3 +/- 2.1 cm H2O during expiratory washout and by 7.3 +/- 1.3 cm H2O during the combination of the two modes, whereas it remained unchanged during optimized mechanical ventilation alone. In conclusion, increasing respiratory rate and reducing instrumental dead space during conventional mechanical ventilation is as efficient as expiratory washout to reduce PaCO2 in patients with severe ARDS and permissive hypercapnia. When used in combination, both techniques have additive effects and result in PaCO2 levels close to normal values. PMID:10390383

  13. Maintaining Adequate Carbon Dioxide Washout for an Advanced Extravehicular Mobility Unit

    NASA Technical Reports Server (NTRS)

    Chullen, Cinda; Navarro, Moses; Conger, Bruce; Korona, Adam; McMillin, Summer; Norcross, Jason; Swickrath, Mike

    2013-01-01

    Over the past several years, NASA has realized tremendous progress in technology development that is aimed at the production of an Advanced Extravehicular Mobility Unit (AEMU). Of the many functions provided by the spacesuit and portable life support subsystem within the AEMU, delivering breathing gas to the astronaut along with removing the carbon dioxide (CO2) remains one of the most important environmental functions that the AEMU can control. Carbon dioxide washout is the capability of the ventilation flow in the spacesuit helmet to provide low concentrations of CO2 to the crew member to meet breathing requirements. CO2 washout performance is a critical parameter needed to ensure proper and sufficient designs in a spacesuit and in vehicle applications such as sleep stations and hygiene compartments. Human testing to fully evaluate and validate CO2 washout performance is necessary but also expensive due to the levied safety requirements. Moreover, correlation of math models becomes challenging because of human variability and movement. To supplement human CO2 washout testing, a breathing capability will be integrated into a suited manikin test apparatus to provide a safe, lower cost, stable, easily modeled alternative to human testing. Additionally, this configuration provides NASA Johnson Space Center (JSC) the capability to evaluate CO2 washout under off-nominal conditions that would otherwise be unsafe for human testing or difficult due to fatigue of a test subject. Testing has been under way in-house at JSC and analysis has been initiated to evaluate whether the technology provides sufficient performance in ensuring that the CO2 is removed sufficiently and the ventilation flow is adequate for maintaining CO2 washout in the AEMU spacesuit helmet of the crew member during an extravehicular activity. This paper will review recent CO2 washout testing and analysis activities, testing planned in-house with a spacesuit simulator, and the associated analytical work

  14. Nitrogen washout during tidal breathing with superimposed high-frequency chest wall oscillation.

    PubMed

    Harf, A; Zidulka, A; Chang, H K

    1985-08-01

    In order to assess the efficacy of high-frequency chest wall oscillation (HFCWO) superimposed on tidal ventilation, multiple-breath nitrogen washout curves were obtained in 7 normal seated subjects. To maintain a regular breathing pattern throughout the study, the subjects breathed synchronously with a Harvard ventilator set at a constant tidal volume and frequency for each subject during a trial period. Washout curves were obtained during 3 different maneuvers performed in random order. Series A was the control condition with no superimposed HFCWO. In Series B and C, HFCWO at 5 Hz was superimposed on the regulated tidal breathing; the magnitude of the oscillatory tidal volume measured at the airway opening was 20 ml for Series B and 40 ml for Series C. The nitrogen washout was clearly faster in Series C than in Series A for each subject. In Series B, there was an interindividual variability, with a washout rate either equal to that in Maneuver A or in Maneuver C, or intermediate between the two. When these washout curves were analyzed in terms of a simple monocompartment model, the time constant of the washout was found to decrease by 16 +/- 11% in Series B, and 25 +/- 7% in Series C compared with that in Series A. In this group of normal subjects, the correction of any inhomogeneity in the distribution of the ventilation is unlikely to explain these results because of the close fit of all washout curves to a monoexponential model. It is postulated that during inspiration HFCWO enhances gas mixing in the lung periphery and that during expiration it improves gas mixing in the airways.(ABSTRACT TRUNCATED AT 250 WORDS)

  15. Plume washout around a major coal-fired power plant: results of a single storm event

    SciTech Connect

    Chen, N. C.J.; Lindberg, S. E.; Saylor, R. E.

    1980-01-01

    Statistical analysis of precipitation chemistry from a 0.67-cm rain event in areas upwind and downwind of a 3160 MW coal-fired power plant indicated significantly higher sulfate and nitrate deposition rates in the target area, but no significant differences in H/sup +/, NH/sub 4//sup +/, or trace metal deposition rates or in concentrations of any components between target and control areas. Plume washout of sulfate in the target area exhibited a maximum deposition rate approx. 45% above the mean deposition rate of the control area at a site 12 km from the stack and for a plume residence time of approx. 1 to 2 h. Aerosol washout calculations suggested that approx. 70% of the observed excess deposition rate of sulfate could be attributed to sulfate aerosol; however, the variability in rainfall intensity makes it impossible to ascribe all of the difference in sulfate deposition to plume washout alone.

  16. Washout resistance of fast-setting pozzolan cement under various root canal irrigants

    PubMed Central

    Jang, Ga-Yeon; Park, Su-Jung; Heo, Seok-Mo; Yu, Mi-Kyung; Lee, Kwang-Won

    2013-01-01

    Objectives Fast-setting pozzolan cement (Endocem, Maruchi) was recently developed. The aim of this study was to investigate the effects of various root canal irrigants on the washout of Endocem in comparison to the previously marketed mineral trioxide aggregate (ProRoot; Dentsply) in a furcal perforation model. Materials and Methods ProRoot and Endocem were placed into acrylic molds on moist Oasis. Each mold was then immediately exposed to either physiologic saline, 2.5% sodium hypochlorite (NaOCl), or 2% chlorhexidine (CHX) under gentle shaking for five minutes. Washout testing was performed by scoring scanning electron microscope (SEM) images. Results Endocem exhibited higher washout resistance compared to ProRoot, especially in the NaOCl group. Conclusions These results suggest that Endocem can be considered a useful repair material for furcal perforation, especially in a single-visit scenario. PMID:24303361

  17. Combustion Tests of Rocket Motor Washout Material: Focus on Air toxics Formation Potential and Asbestos Remediation

    SciTech Connect

    G. C. Sclippa; L. L. Baxter; S. G. Buckley

    1999-02-01

    The objective of this investigation is to determine the suitability of cofiring as a recycle / reuse option to landfill disposal for solid rocket motor washout residue. Solid rocket motor washout residue (roughly 55% aluminum powder, 40% polybutadiene rubber binder, 5% residual ammonium perchlorate, and 0.2-1% asbestos) has been fired in Sandia's MultiFuel Combustor (MFC). The MFC is a down-fired combustor with electrically heated walls, capable of simulating a wide range of fuel residence times and stoichiometries. This study reports on the fate of AP-based chlorine and asbestos from the residue following combustion.

  18. Evaluation of Heat Checking and Washout of Heat Resistant Superalloys and Coatings for Die inserts

    SciTech Connect

    David Schwam; John F. Wallace; Yulong Zhu; Edward Courtright; Harold Adkins

    2005-01-30

    This project had two main objectives: (1) To design, fabricate and run a full size test for evaluating soldering and washout in die insert materials. This test utilizes the unique capabilities of the 350 Ton Squeeze Casting machine available in the Case Meal Casting Laboratory. Apply the test to evaluate resistance of die materials and coating, including heat resistant alloys to soldering and washout damage. (2) To evaluate materials and coatings, including heat resistant superalloys, for use as inserts in die casting of aluminum alloys.

  19. Use of lung pressure-volume curves and helium-sulphur hexafluoride washout to detect emphysema in subjects with mild airflow obstruction

    PubMed Central

    Pereira, R Petrik; Hunter, D; Pride, N B

    1981-01-01

    Mild abnormalities of peripheral lung function can be detected by simple methods, but it remains difficult to determine when these changes are the result of emphysema rather than disease of the airways. We have compared the value of measurements of lung distensibility and a multibreath test of helium (He) and sulphur hexafluoride (SF6) washout in distinguishing between six men with mild impairment of airway function caused by asthma (group A) and six men with similar airway function but probable widespread emphysema (group E). In group E there were striking abnormalities in the static pressure-volume curve of the lungs (reduced lung recoil pressures, increased chord compliance, increased shape factor) and the relation between maximum expiratory flow and lung recoil pressure fell within the normal range. In group A there were only minor abnormalities in lung distensibility and maximum expiratory flow was reduced at a standard lung recoil pressure. In addition carbon monoxide transfer coefficient was reduced in group E but normal in group A. Normal values for He-SF6 washout were similar to those previously described. Differences in He-SF6 washout between group A and group E men were small and in part accounted for by differences in functional residual capacity. In subjects with lung disease, end-tidal He and SF6 concentrations during washout were erratic and it was sometimes impossible to define a crossover point. We conclude that in our hands this technique is less useful for detecting acinar disease than are measurements of lung distensibility or carbon monoxide transfer. Considerable changes in lung distensibility may occur at an early stage in the natural history of emphysema and are readily distinguishable from the small changes that occur in mild asthma. Images PMID:7292378

  20. The washout of combustion-generated hydrogen chloride. [rocket exhaust raindrop scavenging quantification

    NASA Technical Reports Server (NTRS)

    Fenton, D. L.; Purcell, R. Y.; Hrdina, D.; Knutson, E. O.

    1980-01-01

    The coefficient for the washout from a rocket exhaust cloud of HCl generated by the combustion of an ammonium perchlorate-based solid rocket propellant such as that to be used for the Space Shuttle Booster is determined. A mathematical model of HCl scavenging by rain is developed taking into account rain droplet size, fall velocity and concentration under various rain conditions, partitioning of exhaust HCl between liquid and gaseous phases, the tendency of HCl to promote water vapor condensation and the concentration and size of droplets within the exhaust cloud. The washout coefficient is calculated as a function of total cloud water content, total HCl content at 100% relative humidity, condensation nuclei concentration and rain intensity. The model predictions are compared with experimental results obtained in scavenging tests with solid rocket exhaust and raindrops of different sizes, and the large reduction in washout coefficient at high relative humidities predicted by the model is not observed. A washout coefficient equal to 0.0000512 times the -0.176 power of the mass concentration of HCl times the 0.773 power of the rainfall intensity is obtained from the experimental data.

  1. Effect of hematocrit and systolic blood pressure on cerebral blood flow in newborn infants

    SciTech Connect

    Younkin, D.P.; Reivich, M.; Jaggi, J.L.; Obrist, W.D.; Delivoria-Papadopoulos, M.

    1987-06-01

    The effects of hematocrit and systolic blood pressure on cerebral blood flow were measured in 15 stable, low birth weight babies. CBF was measured with a modification of the xenon-133 (/sup 133/Xe) clearance technique, which uses an intravenous bolus of /sup 133/Xe, an external chest detector to estimate arterial /sup 133/Xe concentration, eight external cranial detectors to measure cephalic /sup 133/Xe clearance curves, and a two-compartmental analysis of the cephalic /sup 133/Xe clearance curves to estimate CBF. There was a significant inverse correlation between hematocrit and CBF, presumably due to alterations in arterial oxygen content and blood viscosity. Newborn CBF varied independently of systolic blood pressure between 60 and 84 mm Hg, suggesting an intact cerebrovascular autoregulatory mechanism. These results indicate that at least two of the factors that affect newborn animal CBF are operational in human newborns and may have important clinical implications.

  2. Analysis of metabolic washout of positron emitters produced during carbon ion head and neck radiotherapy

    SciTech Connect

    Helmbrecht, Stephan; Enghardt, Wolfgang; Parodi, Katia; Didinger, Bernd; Debus, Jürgen; Kunath, Daniela; Priegnitz, Marlen; Fiedler, Fine

    2013-09-15

    Purpose: Particle Therapy Positron Emission Tomography (PT-PET) is a suitable method for verification of therapeutic dose delivery by measurements of irradiation-induced β{sup +}-activity. Due to metabolic processes in living tissue β{sup +}-emitters can be removed from the place of generation. This washout is a limiting factor for image quality. The purpose of this study is to investigate whether a washout model obtained by animal experiments is applicable to patient data.Methods: A model for the washout has been developed by Mizuno et al. [Phys. Med. Biol. 48(15), 2269–2281 (2003)] and Tomitani et al. [Phys. Med. Biol. 48(7), 875–889 (2003)]. It is based upon measurements in a rabbit in living and dead conditions. This model was modified and applied to PET data acquired during the experimental therapy project at GSI Helmholtzzentrum für Schwerionenforschung Darmstadt, Germany. Three components are expected: A fast one with a half life of 2 s, a medium one in the range of 2–3 min, and a slow component of the order of 2–3 h. Ten patients were selected randomly for investigation of the fast component. To analyze the other two components, 12 one-of-a-kind measurements from a single volunteer patient are available.Results: A fast washout on the time scale of a few seconds was not observed in the patient data. The medium processes showed a mean half life of 155.7 ± 4.6 s. This is in the expected range. Fractions of the activity not influenced by the washout were found.Conclusions: On the time scale of an in-beam or in-room measurement only the medium-time washout processes play a remarkable role. A slow component may be neglected if the measurements do not exceed 20 min after the end of the irradiation. The fast component is not observed due to the low relative blood filled volume in the brain.

  3. Free thyroxine in needle washout after fine needle aspiration biopsy of toxic thyroid nodules.

    PubMed

    Raikov, Nikolai; Nonchev, Boyan; Chaushev, Borislav; Vjagova, Diyana; Todorov, Svetoslav; Bocheva, Yana; Malceva, Daniela; Vicheva, Snejinka; Raikova, Asyia; Argatska, Antoaneta; Raikov, Miroslav

    2016-01-01

    The main diagnostic tool for toxic adenomas (TA) is radionuclide imaging indicated in patients with evidence of thyroid nodules in combination with thyrotoxic syndrome. Thyroid ultrasound and fine-needle aspiration biopsy (FNAB) are widely used for the valuation of thyroid masses. There is no literature data concerning the utility of FNAB and related tests for the diagnosis of hyperfunctioning thyroid nodules. The purpose of this study is to determine the levels of free thyroxine (FT4) in the needle washout after FNAB of hot thyroid nodules. The results of our study show that the FT4 levels in needle washout from TA were significantly higher than the surrounding parenchyma and correlated with the hormonal changes in patients with thyroid hyperfunctioning nodules. Further studies on a large number of patients are needed to refine the diagnostic value of this method and evaluate its importance in quantitative risk assessment of thyroid autonomy. PMID:26841375

  4. [Determination of ratios of acid pollutant washout in the center of Spain].

    PubMed

    Fernandez Patier, R; Esteban Lefler, M; De la Serna, J; Diez Hernandez, P

    1990-01-01

    Samples were simultaneously taken of precipitation and atmospheric aerosol in two (rural and urban) stations, during 1986 and 1987, in which sulphates, nitrates and chlorides were analyzed by ionic chromatography. The wet deposition of the S and N composites were greater in the urban than in the rural area, and opposite was true for the chlorides. Regarding the aerosols, the average biennial concentrations of the anions studied were greater urban than in the rural area. Based on the figures obtained for the precipitation and the atmospheric aerosols, the washout ratios of each anion and the non-marine sulphates were determined. Both stations that the sulphates as a whole and the non-marine sulphates had very similar washout ratios while those of nitrates were greater in the rural area. The potential regressions between the rates at which they were washed away and the volume of precipitations reveal excellent correlation coefficients.

  5. Free thyroxine in needle washout after fine needle aspiration biopsy of toxic thyroid nodules.

    PubMed

    Raikov, Nikolai; Nonchev, Boyan; Chaushev, Borislav; Vjagova, Diyana; Todorov, Svetoslav; Bocheva, Yana; Malceva, Daniela; Vicheva, Snejinka; Raikova, Asyia; Argatska, Antoaneta; Raikov, Miroslav

    2016-01-01

    The main diagnostic tool for toxic adenomas (TA) is radionuclide imaging indicated in patients with evidence of thyroid nodules in combination with thyrotoxic syndrome. Thyroid ultrasound and fine-needle aspiration biopsy (FNAB) are widely used for the valuation of thyroid masses. There is no literature data concerning the utility of FNAB and related tests for the diagnosis of hyperfunctioning thyroid nodules. The purpose of this study is to determine the levels of free thyroxine (FT4) in the needle washout after FNAB of hot thyroid nodules. The results of our study show that the FT4 levels in needle washout from TA were significantly higher than the surrounding parenchyma and correlated with the hormonal changes in patients with thyroid hyperfunctioning nodules. Further studies on a large number of patients are needed to refine the diagnostic value of this method and evaluate its importance in quantitative risk assessment of thyroid autonomy.

  6. Model simulations of rainout and washout from a warm stratiform cloud

    NASA Technical Reports Server (NTRS)

    Xing, Lin; Chameides, William L.

    1990-01-01

    A one-dimensional, time-dependent cloud model with parameterized microphysics is used to investigate the processes which control the rainout and washout of soluble gases from warm, precipitating stratiform clouds. Calculations are presented simulating the distributions of soluble species within and below the cloud layer and in the precipitating raindrops as a function of time and species' solubility. Calculations indicate that for species with low solubility, wet removal processes are relatively slow and thus do not significantly affect the species' gas-phase abundance. As a result, the removal of low-solubility species by rainout and washout is controlled by thermodynamic processes with the concentration of the species in cloud and rainwater largely determined by the species' solubility. For highly soluble species on the other hand, dissolution into cloud droplets and removal in rain is quite rapid and the abundance of highly soluble species within and below the cloud falls rapidly as soon as the precipitation begins.

  7. Rebound in ventilator-associated pneumonia rates during a prevention checklist washout period.

    PubMed

    Cheema, Ali A; Scott, Annette M; Shambaugh, Karen J; Shaffer-Hartman, Jacqueline N; Dechert, Ronald E; Hieber, Susan M; Gosbee, John W; Niedner, Matthew F

    2011-09-01

    OBJECTIVE To describe the washout effect after stopping a prevention checklist for ventilator-associated pneumonia (VAP). METHODS VAP rates were prospectively monitored for special cause variation over 42 months in a paediatric intensive care unit. A VAP prevention bundle was implemented, consisting of head of bed elevation, oral care, suctioning device management, ventilator tubing care, and standard infection control precautions. Key practices of the bundle were implemented with a checklist and subsequently incorporated into the nursing and respiratory care bedside flow sheets to achieve long-term sustainability. Compliance with the VAP bundle was monitored throughout. The timeline for the project was retrospectively categorised into the benchmark phase, the checklist phase (implementation), the checklist washout phase, and the flowsheet phase (cues in the flowsheet). RESULTS During the checklist phase (12 months), VAP bundle compliance rose from <50% to >75% and the VAP rate fell from 4.2 to 0.7 infections per 1000 ventilator days (p<0.059). Unsolicited qualitative feedback from frontline staff described overburdensome documentation requirements, form fatigue, and checklist burnout. During the checklist washout phase (4 months), VAP rates rose to 4.8 infections per 1000 ventilator days (p<0.042). In the flowsheet phase, the VAP rate dropped to 0.8 infections per 1000 ventilator days (p<0.047). CONCLUSIONS Salient cues to drive provider behaviour towards best practice are helpful to sustain process improvement, and cessation of such cues should be approached warily. Initial education, year-long habit formation, and effective early implementation demonstrated no appreciable effect on the VAP rate during the checklist washout period.

  8. Plume washout from a major coal-fired power plant: a case study

    SciTech Connect

    Chen, N.C.J.; Saylor, R.E.

    1980-11-01

    A precipitation chemistry network (approx. 300 km/sup 2/) consisting of 19 automatic collectors was installed around a 3200-MW coal-fired power plant located in northwest Georgia. The purpose of this study was to investigate the local plume washout from two 300-m smokestacks. Rain samples and plume directions for a single storm (December 13, 1979) were analyzed. The maximum target area deposition rates for sulfate and nitrate were found to be approx. 45% above the mean deposition rate of the control area (SO/sub 4//sup 2 -/, 1.23 +- 0.14; NO/sub 3//sup -/, 0.65 +- 0.09 nmol cm/sup -2/ h/sup -1/). The maximum deposition rates for sulfate and nitrate were reached for a plume residence time of approx. 1 h at a site approx. 12 km SE of the power plant. Aerosol washout modeling suggested that approx. 70% of the observed excess deposition rate could be attributed to sulfate aerosol derived from the plume. However, nitrate aerosol modeling could account for only 36% of the observed excess nitrate deposition rate. The variability in rainfall intensity makes it impossible to ascribe all of the differences in sulfate and nitrate deposition to plume washout alone.

  9. Analytic model for washout of HCl(g) from dispersing rocket exhaust clouds

    NASA Technical Reports Server (NTRS)

    Pellett, G. L.

    1981-01-01

    The potential is investigated that precipitation scavenging of HCl from large solid rocket exhaust clouds may result in unacceptably acidic rain in the Cape Canaveral, Florida, area before atmospheric dispersion reduces HCl concentrations to safe limits. Several analytic expressions for HCl(g) and HCl(g + aq) washout are derived; a geometric mean washout coefficient is recommended. A previous HCl washout model is refined and applied to a space shuttle case (70 t HCl exhausted up to 4 km) and eight Titan 3 (60 percent less exhaust) dispersion cases. The vertical column density (sigma) decays were deduced by application of a multilayer Gaussian diffusion model to seven standard meteorological regimes for overland advection. The Titan 3 decays of sigma and initial rain pH differed greatly among regimes; e.g., a range of 2 pH units was spanned at x 100 km downwind and t = 2 hr. Environmentally significant pH's .5 for infrequent exposures were shown possible at X = 50 km and t 5 hr for the two least dispersive Titan 3 cases. Representative examples of downwind rainwater pH and G(X) are analyzed. Factors affecting the validity of the results are discussed.

  10. Bayesian population analysis of a washin-washout physiologically based pharmacokinetic model for acetone

    SciTech Connect

    Moerk, Anna-Karin; Jonsson, Fredrik; Johanson, Gunnar

    2009-11-01

    The aim of this study was to derive improved estimates of population variability and uncertainty of physiologically based pharmacokinetic (PBPK) model parameters, especially of those related to the washin-washout behavior of polar volatile substances. This was done by optimizing a previously published washin-washout PBPK model for acetone in a Bayesian framework using Markov chain Monte Carlo simulation. The sensitivity of the model parameters was investigated by creating four different prior sets, where the uncertainty surrounding the population variability of the physiological model parameters was given values corresponding to coefficients of variation of 1%, 25%, 50%, and 100%, respectively. The PBPK model was calibrated to toxicokinetic data from 2 previous studies where 18 volunteers were exposed to 250-550 ppm of acetone at various levels of workload. The updated PBPK model provided a good description of the concentrations in arterial, venous, and exhaled air. The precision of most of the model parameter estimates was improved. New information was particularly gained on the population distribution of the parameters governing the washin-washout effect. The results presented herein provide a good starting point to estimate the target dose of acetone in the working and general populations for risk assessment purposes.

  11. The washout effects of rainfall on atmospheric particulate pollution in two Chinese cities.

    PubMed

    Guo, Ling-Chuan; Zhang, Yonghui; Lin, Hualiang; Zeng, Weilin; Liu, Tao; Xiao, Jianpeng; Rutherford, Shannon; You, Jing; Ma, Wenjun

    2016-08-01

    Though rainfall is recognized as one of the main mechanisms to reduce atmospheric particulate pollution, few studies have quantified this effect, particularly the corresponding lag effect and threshold. This study aimed to investigate the association between rainfall and air quality using a distributed lag non-linear model. Daily data on ambient PM2.5 and PM2.5-10 (particulate matter with an aerodynamic diameter less than 2.5 μm and from 2.5 to 10 μm) and meteorological factors were collected in Guangzhou and Xi'an from 2013 to 2014. A better washout effect was found for PM2.5-10 than for PM2.5, and the rainfall thresholds for both particle fractions were 7 mm in Guangzhou and 1 mm in Xi'an. The decrease in PM2.5 levels following rain lasted for 3 and 6 days in Guangzhou and Xi'an, respectively. Rainfall had a better washout effect in Xi'an compared with that in Guangzhou. Findings from this study contribute to a better understanding of the washout effects of rainfall on particulate pollution, which may help to understand the category and sustainability of dust-haze and enforce anthropogenic control measures in time. PMID:27203467

  12. Microcrustacea in flowing water - experimental-analysis of washout times and a field-test

    USGS Publications Warehouse

    Richardson, W.B.

    1992-01-01

    1. Flow-chamber experiments were conducted to evaluate the ability of microcrustacea to maintain position in moving water. These results were compared to distributions of zooplankton and water velocity in a stream pool to determine the relationship of animal density to water movement and swimming ability.^2. Cladocerans exhibited negative rheotaxis (directed behaviour against a current) but poor ability to maintain position at velocities >2.5 Cm s-1. Daphnia and scapholeberis were better at avoiding washout than moina and diaphanosoma. At velocities 2.5 Cm s-1, scapholeberis >3.2 Cm s-1 and eucyclops >7.75 Cm s-1. Washout time of daphnia and scapholeberis was positively related to body size and negatively to water velocity and possession of eggs. Washout was inversely related to water velocity for eucyclops.^4. Highest densities of microcrustacea in a stream pool were found in non-flowing or downstream zones of the pool. Benthic (hydracarina, harpacticoid copepods, ostracods) and fast-swimming (cyclopoids) forms were most common in flowing zones. Facultatively benthic cladocera were abundant in regions of no flow. Rotifers and immature copepods were most abundant at the downstream end of the pool.^5. Behavioural mechanisms for remaining in stream pools at times of high flow appear to include: (i) flow avoidance (simocephalus, chydorus, scapholeberis and cyclopoids), (ii) use of benthic habitat (ostracods, harpacticoids, hydracarina), (iii) strong swimming ability (cyclopoids).

  13. Evaluation of pulmonary perfusion in lung regions showing isolated xenon-133 ventilation washout defects

    SciTech Connect

    Bushnell, D.L.; Sood, K.B.; Shirazi, P.; Pal, I. )

    1990-08-01

    Xenon-133 washout phase imaging is often used to help determine whether the etiology of a perfusion defect is embolic or due to pulmonary parenchymal pathology, such as chronic obstructive pulmonary disease. This study was designed to evaluate the pulmonary blood flow patterns associated with isolated defects on xenon washout images. Scintigraphic lung studies were reviewed until 100 cases with abnormal ventilation results were obtained. Ventilation abnormalities were compared with the corresponding perfusion scan results at the same anatomic site. Of the 208 individual lung regions with xenon abnormalities, 111 showed isolated washout defects (that is, with normal washin). Ninety-four of these 111 sites showed either normal perfusion or a small, nonsegmental corresponding perfusion defect. Three segmental perfusion defects were noted in association with isolated xenon retention. In each of these cases, however, the patient was felt actually to have pulmonary embolism. Thus, it is recommended that, for interpretation of scintigraphic images in the assessment of pulmonary embolism, lung pathology associated with isolated xenon retention not be considered a potential cause for large or segmental perfusion defects.

  14. Multiple-Breath Washout as a Lung Function Test in Cystic Fibrosis. A Cystic Fibrosis Foundation Workshop Report.

    PubMed

    Subbarao, Padmaja; Milla, Carlos; Aurora, Paul; Davies, Jane C; Davis, Stephanie D; Hall, Graham L; Heltshe, Sonya; Latzin, Philipp; Lindblad, Anders; Pittman, Jessica E; Robinson, Paul D; Rosenfeld, Margaret; Singer, Florian; Starner, Tim D; Ratjen, Felix; Morgan, Wayne

    2015-06-01

    The lung clearance index (LCI) is a lung function parameter derived from the multiple-breath washout (MBW) test. Although first developed 60 years ago, the technique was not widely used for many years. Recent technological advances in equipment design have produced gains in popularity for this test among cystic fibrosis (CF) researchers and clinicians, particularly for testing preschool-aged children. LCI has been shown to be feasible and sensitive to early CF lung disease in patients of all ages from infancy to adulthood. A workshop was convened in January 2014 by the North American Cystic Fibrosis Foundation to determine the readiness of the LCI for use in multicenter clinical trials as well as clinical care. The workshop concluded that the MBW text is a valuable potential outcome measure for CF clinical trials in preschool-aged patients and in older patients with FEV1 in the normal range. However, gaps in knowledge about the choice of device, gas, and standardization across systems are key issues precluding its use as a clinical trial end point in infants. Based on the current evidence, there are insufficient data to support the use of LCI or MBW parameters in the routine clinical management of patients with CF. PMID:26075554

  15. Closed circuit rebreathing to achieve inert gas wash-in for multiple breath wash-out

    PubMed Central

    O'Neill, Katherine; Downey, Damian G.; Elborn, J. Stuart; Bell, Nicholas J.; Smith, Jaclyn; Owers-Bradley, John

    2016-01-01

    Multiple breath wash-out (MBW) testing requires prior wash-in of inert tracer gas. Wash-in efficiency can be enhanced by a rebreathing tracer in a closed circuit. Previous attempts to deploy this did not account for the impact of CO2 accumulation on patients and were unsuccessful. We hypothesised that an effective rebreathe wash-in could be delivered and it would not alter wash-out parameters. Computer modelling was used to assess the impact of the rebreathe method on wash-in efficiency. Clinical testing of open and closed circuit wash-in–wash-out was performed in healthy controls and adult patients with cystic fibrosis (CF) using a circuit with an effective CO2 scrubber and a refined wash-in protocol. Wash-in efficiency was enhanced by rebreathing. There was no difference in mean lung clearance index between the two wash-in methods for controls (6.5 versus 6.4; p=0.2, n=12) or patients with CF (10.9 versus 10.8; p=0.2, n=19). Test time was reduced by rebreathe wash-in (156 versus 230 s for CF patients, p<0.001) and both methods were well tolerated. End wash-in CO2 was maintained below 2% in most cases. Rebreathe–wash-in is a promising development that, when correctly deployed, reduces wash-in time and facilitates portable MBW testing. For mild CF, wash-out outcomes are equivalent to an open circuit. PMID:27730167

  16. Computerized Mathematical Models of Spray Washout of Airborne Contaminants (Radioactivity) in Containment Vessels.

    2003-05-23

    Version 01 Distribution is restricted to the United States Only. SPIRT predicts the washout of airborne contaminants in containment vessels under postulated loss-of-coolant accident (LOCA) conditions. SPIRT calculates iodine removal constants (lambdas) for post-LOCA containment spray systems. It evaluates the effect of the spectrum of drop sizes emitted by the spray nozzles, the effect of drop coalescence, and the precise solution of the time-dependent diffusion equation. STEAM-67 routines are included for calculating the properties ofmore » steam and water according to the 1967 ASME Steam Tables.« less

  17. Utilizing a Suited Manikin Test Apparatus and Space Suit Ventilation Loop to Evaluate Carbon Dioxide Washout

    NASA Technical Reports Server (NTRS)

    Chullen, Cinda; Conger, Bruce; Korona, Adam; Kanne, Bryan; McMillin, Summer; Paul, Thomas; Norcross, Jason; Alonso, Jesus Delgado; Swickrath, Mike

    2015-01-01

    NASA is pursuing technology development of an Advanced Extravehicular Mobility Unit (AEMU) which is an integrated assembly made up of primarily a pressure garment system and a portable life support subsystem (PLSS). The PLSS is further composed of an oxygen subsystem, a ventilation subsystem, and a thermal subsystem. One of the key functions of the ventilation system is to remove and control the carbon dioxide (CO2) delivered to the crewmember. Carbon dioxide washout is the mechanism by which CO2 levels are controlled within the space suit helmet to limit the concentration of CO2 inhaled by the crew member. CO2 washout performance is a critical parameter needed to ensure proper and robust designs that are insensitive to human variabilities in a space suit. A suited manikin test apparatus (SMTA) was developed to augment testing of the PLSS ventilation loop in order to provide a lower cost and more controlled alternative to human testing. The CO2 removal function is performed by the regenerative Rapid Cycle Amine (RCA) within the PLSS ventilation loop and its performance is evaluated within the integrated SMTA and Ventilation Loop test system. This paper will provide a detailed description of the schematics, test configurations, and hardware components of this integrated system. Results and analysis of testing performed with this integrated system will be presented within this paper.

  18. Maintaining Adequate CO2 Washout for an Advanced EMU via a New Rapid Cycle Amine Technology

    NASA Technical Reports Server (NTRS)

    Chullen, Cinda; Conger, Bruce

    2012-01-01

    Over the past several years, NASA has realized tremendous progress in Extravehicular Activity (EVA) technology development. This has been evidenced by the progressive development of a new Rapid Cycle Amine (RCA) system for the Advanced Extravehicular Mobility Unit (AEMU) Portable Life Support Subsystem (PLSS). The PLSS is responsible for the life support of the crew member in the spacesuit. The RCA technology is responsible for carbon dioxide (CO2) and humidity control. Another aspect of the RCA is that it is on-back vacuum-regenerable, efficient, and reliable. The RCA also simplifies the PLSS schematic by eliminating the need for a condensing heat exchanger for humidity control in the current EMU. As development progresses on the RCA, it is important that the sizing be optimized so that the demand on the PLSS battery is minimized. As well, maintaining the CO2 washout at adequate levels during an EVA is an absolute requirement of the RCA and associated ventilation system. Testing has been underway in-house at NASA Johnson Space Center and analysis has been initiated to evaluate whether the technology provides exemplary performance in ensuring that the CO2 is removed sufficiently and the ventilation flow is adequate for maintaining CO2 washout in the AEMU spacesuit helmet of the crew member during an EVA. This paper will review the recent developments of the RCA unit, testing planned in-house with a spacesuit simulator, and the associated analytical work along with insights from the medical aspect on the testing. 1

  19. Multiple breath washout analysis in infants: quality assessment and recommendations for improvement.

    PubMed

    Anagnostopoulou, Pinelopi; Egger, Barbara; Lurà, Marco; Usemann, Jakob; Schmidt, Anne; Gorlanova, Olga; Korten, Insa; Roos, Markus; Frey, Urs; Latzin, Philipp

    2016-03-01

    Infant multiple breath washout (MBW) testing serves as a primary outcome in clinical studies. However, it is still unknown whether current software algorithms allow between-centre comparisons. In this study of healthy infants, we quantified MBW measurement errors and tried to improve data quality by simply changing software settings. We analyzed best quality MBW measurements performed with an ultrasonic flowmeter in 24 infants from two centres in Switzerland with the current software settings. To challenge the robustness of these settings, we also used alternative analysis approaches. Using the current analysis software, the coefficient of variation (CV) for functional residual capacity (FRC) differed significantly between centres (mean  ±  SD (%): 9.8  ±  5.6 and 5.8  ±  2.9, respectively, p  =  0.039). In addition, FRC values calculated during the washout differed between  -25 and  +30% from those of the washin of the same tracing. Results were mainly influenced by analysis settings and temperature recordings. Changing few algorithms resulted in significantly more robust analysis. Non-systematic inter-centre differences can be reduced by using correctly recorded environmental data and simple changes in the software algorithms. We provide implications that greatly improve infant MBW outcomes' quality and can be applied when multicentre trials are conducted. PMID:26849570

  20. Emptying patterns of the lung studied by multiple-breath N2 washout

    NASA Technical Reports Server (NTRS)

    Lewis, S. M.

    1978-01-01

    Changes in the nitrogen concentration seen during the single-breath nitrogen washout reflect changes in relative flow (ventilation) from units with differing ventilation/volume ratios. The multiple-breath washout provides sufficient data on ventilation for units with varying ventilation/volume ratios to be plotted as a function of the volume expired. Flow from the dead space may also be determined. In young normals the emptying patterns are narrow and unimodal throughout the alveolar plateau with little or no flow from the dead space at the end of the breath. Older normals show more flow from the dead space, particularly toward the end of the breath, and some show a high ventilation/volume ratio mode early in the breath. Patients with obstructive lung disease have a high flow from the dead space which is present throughout the breath. A well ventilated mode at the end of the breath is seen in some obstructed subjects. Patients with cystic fibrosis showed a poorly ventilated mode appearing at the end of the breath as well as a very high dead space.

  1. CO2 Washout Testing Using Various Inlet Vent Configurations in the Mark-III Space Suit

    NASA Technical Reports Server (NTRS)

    Korona, F. Adam; Norcross, Jason; Conger, Bruce; Navarro, Moses

    2014-01-01

    Requirements for using a space suit during ground testing include providing adequate carbon dioxide (CO2) washout for the suited subject. Acute CO2 exposure can lead to symptoms including headache, dyspnea, lethargy and eventually unconsciousness or even death. Symptoms depend on several factors including inspired partial pressure of CO2 (ppCO2), duration of exposure, metabolic rate of the subject and physiological differences between subjects. Computational Fluid Dynamic (CFD) analysis has predicted that the configuration of the suit inlet vent has a significant effect on oronasal CO2 concentrations. The main objective of this test is to characterize inspired oronasal ppCO2 for a variety of inlet vent configurations in the Mark-III space suit across a range of workload and flow rates. As a secondary objective, results will be compared to the predicted CO2 concentrations and used to refine existing CFD models. These CFD models will then be used to help design an inlet vent configuration for the Z-2 space suit, which maximizes oronasal CO2 washout. This test has not been completed, but is planned for January 2014. The results of this test will be incorporated into this paper. The testing methodology used in this test builds upon past CO2 washout testing performed on the Z-1 suit, Rear Entry I-Suit (REI) and the Enhanced Mobility Advanced Crew Escape Suit (EM-ACES). Three subjects will be tested in the Mark-III space suit with each subject performing two test sessions to allow for comparison between tests. Six different helmet inlet vent configurations will be evaluated during each test session. Suit pressure will be maintained at 4.3 psid. Subjects will wear the suit while walking on a treadmill to generate metabolic workloads of approximately 2000 and 3000 BTU/hr. Supply airflow rates of 6 and 4 actual cubic feet per minute (ACFM) will be tested at each workload. Subjects will wear an oronasal mask with an open port in front of the mouth and will be allowed to

  2. Longitudinal changes in central artery stiffness with lifestyle modification, washout, and drug treatment in individuals at risk for cardiovascular disease.

    PubMed

    Aizawa, Kunihiko; Shoemaker, J Kevin; Overend, Tom J; Petrella, Robert J

    2010-08-01

    We assessed 17 middle-aged and older individuals (58.0 +/- 7.9 years, 7 females) at risk for cardiovascular disease regarding: (1) Whether carotid artery stiffness (cAS) would be reduced with a 1-year lifestyle modification program, (2) to what degree cAS would return following washout (mean of 26.9 +/- 4.0 months) from the active intervention, and (3) whether a 24-week telmisartan treatment would reduce cAS more than our lifestyle modification program. cAS by Doppler ultrasound, cardiovascular disease risk factors, and exercise capacity were assessed at three points: Following the 1-year lifestyle modification, following the washout period, and following a 24-week telmisartan treatment. Following telmisartan, systolic blood pressure (SBP) was significantly decreased (114.8 +/- 12.3 mmHg) compared to baseline (127.9 +/- 12.7 mmHg) and following the washout period (126.1 +/- 14.9 mmHg). Similarly, diastolic blood pressure (DBP) was significantly lower following telmisaratn than following the washout period. Exercise capacity was increased following lifestyle modification but returned to the baseline level following the washout period. Following the lifestyle modification program, cAS was significantly reduced, and this reduction was maintained following the washout period. Conversely, the subsequent telmisartan treatment did not change cAS despite a significant blood pressure reduction. These results suggest that the reduced cAS achieved with lifestyle modification may not necessarily disappear following a cessation of the active program, indicating a possible role that family physicians can play in their clinical practice, and also providing a further rationale to promote lifestyle modification as an initial therapy for this population. In contrast, no additional benefit of telmisartan beyond our lifestyle intervention was observed in this study.

  3. Gravitational independence of single-breath washout tests in recumbent dogs

    NASA Technical Reports Server (NTRS)

    Tomioka, Shinichi; Kubo, Susumu; Guy, Harold J. B.; Prisk, G. K.

    1988-01-01

    The effect of gravitational orientation in the mechanism of lung filling and emptying in dogs was examined by conducting simultaneously Ar-bolus and N2 single-breath washout tests (SBWTs) in 10 anesthetized dogs (prone and supine), with three of the dogs subjected to body rotation. Transpulmonary pressure was measured simultaneously, allowing identification of the lung volume above residual volume at which there was an inflection point in the pressure-volume curve. Combined resident gas and bolus SBWTs in recumbent dogs were found to be different from such tests in humans; in dogs, the regional distribution of ventilation was not primarily determined by gravity. The measurements did not make it possible to discern exact mechanisms of filling and emptying, but both processes appear to be related to lung, thorax, and mediastinum interactions and/or differences in regional mechanical properties of the lungs.

  4. Fast real-time moment-ratio analysis of multibreath nitrogen washout in children.

    PubMed

    Kraemer, R; Meister, B

    1985-10-01

    To apply real-time moment-ratio analysis to multibreath N2-washout curves (MBNW) from children, a new processor-controlled device was constructed. Flow and fractional N2 concentration (FN2) were each sampled by 200 Hz. An electromagnetic triple-valve system, with an instrumental dead space of 36 ml and a valve resistance of 0.3 cmH2O . l-1 . s, was connected in series with a pneumotachograph and an N2 analyzer (Ohio 720) placed next to the mouthpiece. A FORTRAN/MACRO program on a PDP 11/23 computer enabled measurement of inspiratory and expiratory flow and FN2 sampling by a 12-bit analog-to-digital converter. The fast real-time digital processing of the N2 and flow signals incorporated filtering, delay compensation, and corrections for the effects of changes in gas composition and temperature. MBNW dynamics of the lungs were studied in 17 healthy and 28 asthmatic children and in 16 patients with cystic fibrosis, evaluating the moment ratios of the washout curves as indices of the ventilation characteristics. Intrasubject variability of the moment ratios (m1/m0, m2/m0) and determination of functional residual capacity (FRC) varied between 6.3 and 14.7% (depending on which parameter is considered) and was comparatively lower than other indices previously investigated in adults. In addition, the sensitivity of the moment ratios for discriminating different stages of ventilation inhomogeneity was superior to other indices. m2/m0 is closely related to the simultaneously measured airway resistance, and the ratio between cumulative expired volume and FRC is correlated with the ratio between residual volume and total lung capacity.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Maintaining Adequate CO2 Washout for an Advanced EMU via a New Rapid Cycle Amine Technology

    NASA Technical Reports Server (NTRS)

    Chullen, Cinda

    2011-01-01

    Over the past several years, NASA has realized tremendous progress in Extravehicular Activity (EVA) technology development. This has been evidenced by the progressive development of a new Rapic Cycle Amine (RCA) system for the Advanced Extravehicular Mobility Unit (AEMU) Portable Life Support Subsystem (PLSS). The PLSS is responsible for the life support of the crew member in the spacesuit. The RCA technology is responsible for carbon dioxide (CO2) and humidity control. Another aspect of the RCA is that it is on-back vacuum-regenerable, efficient, and reliable. The RCA also simplifies the PLSS schematic by eliminating the need for a condensing heat exchanger for humidity control in the current EMU. As development progresses on the RCA, it is important that the sizing be optimized so that the demand on the PLSS battery is minimized. As well, maintaining the CO2 washout at adequate levels during an EVA is an absolute requirement of the RCA and associated ventilation system. Testing has been underway in-house at NASA Johnson Space Center and analysis has been initiated to evaluate whether the technology provides exemplary performance in ensuring that the CO2 is removed sufficiently enough and the ventilation flow is adequate enough to maintain CO2 1 Project Engineer, Space Suit and Crew Survival Systems Branch, Crew and Thermal Systems Division, 2101 NASA Parkway, Houston, TX 77058/EC5. washout in the AEMU spacesuit helmet of the crew member during an EVA. This paper will review the recent developments of the RCA unit, the testing results performed in-house with a spacesuit simulator, and the associated analytical work along with insights from the medical aspect on the testing.

  6. Medullary thyroid carcinoma in a patient with Hashimoto's thyroiditis diagnosed by calcitonin washout from a thyroid nodule.

    PubMed

    Mousa, Umut; Gursoy, Alptekin; Ozdemir, Handan; Moray, Gokhan

    2013-07-01

    Serum calcitonin is a tumor marker used in the diagnosis and follow-up of medullary thyroid carcinoma. Calcitonin washout evaluation is a new method used for suspicious thyroid nodules and lymph nodes. Limited clinical data are present about the efficacy of this method. A 61-year-old female patient with known Hashimoto's thyroditis and an 8-mm hypoechoic nodule was presented with one previously benign fine-needle aspiration cytology (FNAC). On referral to our department, she had a moderately high-serum calcitonin level, and we repeated the FNAC that was reported as nondiagnostic. We performed FNAC for the third time together with calcitonin washout evaluation from the thyroid nodule. The FNAC was again nondiagnostic, but the calcitonin washout level from the thyroid nodule was 152.569 pg/mL. Total thyroidectomy was performed, and the diagnosis was confirmed as medullary thyroid carcinoma. Calcitonin washout evaluation may be a useful method in the differential diagnosis of patients with thyroid nodules having moderately high-serum calcitonin levels.

  7. Compartmental analysis of washout effect in rat brain: in-beam OpenPET measurement using a 11C beam

    NASA Astrophysics Data System (ADS)

    Hirano, Yoshiyuki; Kinouchi, Shoko; Ikoma, Yoko; Yoshida, Eiji; Wakizaka, Hidekazu; Ito, Hiroshi; Yamaya, Taiga

    2013-12-01

    In-beam positron emission tomography (PET) is expected to enable visualization of a dose verification using positron emitters (β+ decay). For accurate dose verification, correction of the washout of the positron emitters should be made. In addition, the quantitative washout rate has a potential usefulness as a diagnostic index, but modeling for this has not been studied yet. In this paper, therefore, we applied compartment analyses to in-beam PET data acquired by our small OpenPET prototype, which has a physically opened field-of-view (FOV) between two detector rings. A rat brain was located at the FOV and was irradiated by a 11C beam. Time activity curves of the irradiated field were measured immediately after the irradiations, and the washout rate was obtained based on two models: the two-washout model (medium decay, k2m; slow decay, k2s) developed in a study of rabbit irradiation; and the two-compartment model used in nuclear medicine, where efflux from tissue to blood (k2), influx (k3) and efflux (k4) from the first to second compartments in tissue were evaluated. The observed k2m and k2s were 0.34 and 0.005 min-1, respectively, which was consistent with the rabbit study. Also k2m was close to the washout rate in cerebral blood flow (CBF) measurements by dynamic PET with 15O-water, while, k2, k3, and k4 were 0.16, 0.15 and 0.007 min-1. Our present work suggested the dynamics of 11C might be relevant to CBF or permeability of a molecule containing 11C atoms might be regulated by a transporter because the k2 was relatively low compared with a simple diffusion tracer.

  8. The risk of river pollution due to washout from contaminated floodplain water bodies during high floods

    NASA Astrophysics Data System (ADS)

    Lyubimova, Tatyana; Lepikhin, Anatoly; Parshakova, Yanina; Tiunov, Alexey

    2016-04-01

    Today, the potential impact of extremely high floods, which in the last years have become a rather frequent weather-related disaster, is the problem of primary concern. In studies of the potential impact of floods the emphasis is placed first of all on the estimation of possible flood zones and the analysis of the flow regimes in these zones. However, in some cases the hydrochemical parameters related to changes in the chemical composition of water are more important than the hydraulic parameters. It is generally believed that the higher is the flow rate, the more intensive is the process of dissolution, i.e. the lower is the concentration of limiting contaminants in water. However, this statement is valid provided that flooding does not activate new sources of water pollution such as contaminated floodplain water bodies located in the vicinity of water supply systems. Being quite reliable and safe at small and moderate discharges, in the case of extremely high level of river waters they become intensive sources of water pollution, essentially limiting the water consumption schedule for downstream water consumers. It should be noted that compared to the well-studied mechanisms of waste discharge due to failure of hydraulic engineering structures by flood waves, the mechanisms of pollutant washout from the contaminated floodplain water bodies by the flood waves is still poorly understood. We analyze the impacts of such weather-related events on the quality of water in the water intake system, taking as an example, the section of the Vyatka River located in the Prikamskaya lowland of the Russian Federation. The risk of river pollution due to washout from the contaminated floodplain water bodies during high floods is studied by hydrodynamical modeling in the framework of combined approach using one-, two- and three-dimensional hydrodynamic models are implemented and by in situ measurements. It is shown that during high floods the removal of pollutants from the

  9. CO2 Washout Testing of the REI and EM-ACES Space Suits

    NASA Technical Reports Server (NTRS)

    Mitchell, Kate; Norcross, Jason

    2011-01-01

    Requirements for using a space suit during ground testing include providing adequate carbon dioxide (CO2) washout for the suited subject. Acute CO2 exposure can lead to symptoms including headache, dyspnea, lethargy and eventually unconsciousness or even death. Symptoms depend on several factors including partial pressure of CO2 (ppCO2), duration of exposure, metabolic rate of the subject and physiological differences between subjects. The objective of this test was to characterize inspired oronasal ppCO2 in the Rear Entry I-Suit (REI) and the Enhanced Mobility Advanced Crew Escape Suit (EM-ACES) across a range of workloads and flow rates for which ground testing is nominally performed. Three subjects were tested in each suit. In all but one case, each subject performed the test twice to allow for comparison between tests. Suit pressure was maintained at 4.3 psid. Subjects wore the suit while resting, performing arm ergometry, and walking on a treadmill to generate metabolic workloads of approximately 500 to 3000 BTU/hr. Supply airflow was varied at 6, 5 and 4 actual cubic feet per minute (ACFM) at each workload. Subjects wore an oronasal mask with an open port in front of the mouth and were allowed to breathe freely. Oronasal ppCO2 was monitored real-time via gas analyzers with sampling tubes connected to the oronasal mask. Metabolic rate was calculated from the total CO2 production measured by an additional gas analyzer at the air outlet from the suit. Real-time metabolic rate was used to adjust the arm ergometer or treadmill workload to meet target metabolic rates. In both suits, inspired CO2 was primarily affected by the metabolic rate of the subject, with increased metabolic rate resulting in increased inspired ppCO2. Suit flow rate also affected inspired ppCO2, with decreased flow causing small increases in inspired ppCO2. The effect of flow was more evident at metabolic rates greater than or equal to 2000 BTU/hr. Results were consistent between suits, with

  10. Carbon Dioxide Washout Testing Using Various Inlet Vent Configurations in the Mark-III Space Suit

    NASA Technical Reports Server (NTRS)

    Korona, F. Adam; Norcross, Jason; Conger, Bruce; Navarro, Moses

    2014-01-01

    Requirements for using a space suit during ground testing include providing adequate carbon dioxide (CO2) washout for the suited subject. Acute CO2 exposure can lead to symptoms including headache, dyspnea, lethargy, and eventually unconsciousness or even death. Symptoms depend on several factors including inspired partial pressure of CO2 (ppCO2), duration of exposure, metabolic rate of the subject, and physiological differences between subjects. Computational Fluid Dynamics (CFD) analysis has predicted that the configuration of the suit inlet vent has a significant effect on oronasal CO2 concentrations. The main objective of this test was to characterize inspired oronasal ppCO2 for a variety of inlet vent configurations in the Mark-III suit across a range of workload and flow rates. Data and trends observed during testing along with refined CFD models will be used to help design an inlet vent configuration for the Z-2 space suit. The testing methodology used in this test builds upon past CO2 washout testing performed on the Z-1 suit, Rear Entry I-Suit, and the Enhanced Mobility Advanced Crew Escape Suit. Three subjects performed two test sessions each in the Mark-III suit to allow for comparison between tests. Six different helmet inlet vent configurations were evaluated during each test session. Suit pressure was maintained at 4.3 psid. Suited test subjects walked on a treadmill to generate metabolic workloads of approximately 2000 and 3000 BTU/hr. Supply airflow rates of 6 and 4 actual cubic feet per minute were tested at each workload. Subjects wore an oronasal mask with an open port in front of the mouth and were allowed to breathe freely. Oronasal ppCO2 was monitored real-time via gas analyzers with sampling tubes connected to the oronasal mask. Metabolic rate was calculated from the CO2 production measured by an additional gas analyzer at the air outlet from the suit. Real-time metabolic rate measurements were used to adjust the treadmill workload to meet

  11. CO2 Washout Testing Using Various Inlet Vent Configurations in the Mark-III Space Suit

    NASA Technical Reports Server (NTRS)

    Korona, F. Adam; Norcross, Jason; Conger, Bruce; Navarro, Moses

    2014-01-01

    Requirements for using a space suit during ground testing include providing adequate carbon dioxide (CO2) washout for the suited subject. Acute CO2 exposure can lead to symptoms including headache, dyspnea, lethargy and eventually unconsciousness or even death. Symptoms depend on several factors including inspired partial pressure of CO2 (ppCO2), duration of exposure, metabolic rate of the subject and physiological differences between subjects. Computational Fluid Dynamic (CFD) analysis has predicted that the configuration of the suit inlet vent has a significant effect on oronasal CO2 concentrations. The main objective of this test was to characterize inspired oronasal ppCO2 for a variety of inlet vent configurations in the Mark-III suit across a range of workload and flow rates. Data and trends observed during testing along with refined CFD models will be used to help design an inlet vent configuration for the Z-2 space suit. The testing methodology used in this test builds upon past CO2 washout testing performed on the Z-1 suit, Rear Entry I-Suit (REI) and the Enhanced Mobility Advanced Crew Escape Suit (EM-ACES). Three subjects performed two test sessions each in the Mark-III suit to allow for comparison between tests. Six different helmet inlet vent configurations were evaluated during each test session. Suit pressure was maintained at 4.3 psid. Suited test subjects walked on a treadmill to generate metabolic workloads of approximately 2000 and 3000 BTU/hr. Supply airflow rates of 6 and 4 actual cubic feet per minute (ACFM) were tested at each workload. Subjects wore an oronasal mask with an open port in front of the mouth and were allowed to breathe freely. Oronasal ppCO2 was monitored real-time via gas analyzers with sampling tubes connected to the oronasal mask. Metabolic rate was calculated from the total oxygen consumption and CO2 production measured by additional gas analyzers at the air outlet from the suit. Realtime metabolic rate measurements were

  12. CO2 Washout Testing Using Various Inlet Vent Configurations in the Mark-III Space Suit

    NASA Technical Reports Server (NTRS)

    Korona, F. Adam; Norcross, Jason; Conger, Bruce; Navarro, Moses

    2014-01-01

    Requirements for using a space suit during ground testing include providing adequate carbon dioxide (CO2) washout for the suited subject. Acute CO2 exposure can lead to symptoms including headache, dyspnea, lethargy and eventually unconsciousness or even death. Symptoms depend on several factors including inspired partial pressure of CO2 (ppCO2), duration of exposure, metabolic rate of the subject and physiological differences between subjects. Computational Fluid Dynamic (CFD) analysis has predicted that the configuration of the suit inlet vent has a significant effect on oronasal CO2 concentrations. The main objective of this test was to characterize inspired oronasal ppCO2 for a variety of inlet vent configurations in the Mark-III suit across a range of workload and flow rates. Data and trends observed during testing along with refined CFD models will be used to help design an inlet vent configuration for the Z-2 space suit. The testing methodology used in this test builds upon past CO2 washout testing performed on the Z-1 suit, Rear Entry I-Suit (REI) and the Enhanced Mobility Advanced Crew Escape Suit (EM-ACES). Three subjects performed two test sessions each in the Mark-III suit to allow for comparison between tests. Six different helmet inlet vent configurations were evaluated during each test session. Suit pressure was maintained at 4.3 psid. Suited test subjects walked on a treadmill to generate metabolic workloads of approximately 2000 and 3000 BTU/hr. Supply airflow rates of 6 and 4 actual cubic feet per minute (ACFM) were tested at each workload. Subjects wore an oronasal mask with an open port in front of the mouth and were allowed to breathe freely. Oronasal ppCO2 was monitored real-time via gas analyzers with sampling tubes connected to the oronasal mask. Metabolic rate was calculated from the total oxygen consumption and CO2 production measured by additional gas analyzers at the air outlet from the suit. Real-time metabolic rate measurements were

  13. Effect of two β-alanine dosing protocols on muscle carnosine synthesis and washout.

    PubMed

    Stellingwerff, Trent; Anwander, Helen; Egger, Andrea; Buehler, Tania; Kreis, Roland; Decombaz, Jacques; Boesch, Chris

    2012-06-01

    Carnosine (β-alanyl-L-histidine) is found in high concentrations in skeletal muscle and chronic β-alanine (BA) supplementation can increase carnosine content. This placebo-controlled, double-blind study compared two different 8-week BA dosing regimens on the time course of muscle carnosine loading and 8-week washout, leading to a BA dose-response study with serial muscle carnosine assessments throughout. Thirty-one young males were randomized into three BA dosing groups: (1) high-low: 3.2 g BA/day for 4 weeks, followed by 1.6 g BA/day for 4 weeks; (2) low-low: 1.6 g BA/day for 8 weeks; and (3) placebo. Muscle carnosine in tibialis-anterior (TA) and gastrocnemius (GA) muscles was measured by 1H-MRS at weeks 0, 2, 4, 8, 12 and 16. Flushing symptoms and blood clinical chemistry were trivial in all three groups and there were no muscle carnosine changes in the placebo group. During the first 4 weeks, the increase for high-low (TA 2.04 mmol/kgww, GA 1.75 mmol/kgww) was ~twofold greater than low-low (TA 1.12 mmol/kgww, GA 0.80 mmol/kgww). 1.6 g BA/day significantly increased muscle carnosine within 2 weeks and induced continual rises in already augmented muscle carnosine stores (week 4-8, high-low regime). The dose-response showed a carnosine increase of 2.01 mmol/kgww per 100 g of consumed BA, which was only dependent upon the total accumulated BA consumed (within a daily intake range of 1.6-3.2 g BA/day). Washout rates were gradual (0.18 mmol/kgww and 0.43 mmol/kgww/week; ~2%/week). In summary, the absolute increase in muscle carnosine is only dependent upon the total BA consumed and is not dependent upon baseline muscle carnosine, the muscle type, or the daily amount of supplemented BA.

  14. CO2 Washout Testing of the REI and EM-ACES Space Suits

    NASA Technical Reports Server (NTRS)

    Mitchell, Kathryn C.; Norcross, Jason

    2012-01-01

    When a space suit is used during ground testing, adequate carbon dioxide (CO2) washout must be provided for the suited subject. Symptoms of acute CO2 exposure depend on partial pressure of CO2 (ppCO2), metabolic rate of the subject, and other factors. This test was done to characterize inspired oronasal ppCO2 in the Rear Entry I-Suit (REI) and the Enhanced Mobility Advanced Crew Escape Suit (EM-ACES) for a range of workloads and flow rates for which ground testing is nominally performed. Three subjects were tested in each suit. In all but one case, each subject performed the test twice. Suit pressure was maintained at 4.3 psid. Subjects wore the suit while resting, performing arm ergometry, and walking on a treadmill to generate metabolic workloads of about 500 to 3000 BTU/hr. Supply airflow was varied between 6, 5, and 4 actual cubic feet per minute (ACFM) at each workload. Subjects wore an oronasal mask with an open port in front of the mouth and were allowed to breathe freely. Oronasal ppCO2 was monitored in real time by gas analyzers with sampling tubes connected to the mask. Metabolic rate was calculated from the total CO2 production measured by an additional gas analyzer at the suit air outlet. Real-time metabolic rate was used to adjust the arm ergometer or treadmill workload to meet target metabolic rates. In both suits, inspired CO2 was affected mainly by the metabolic rate of the subject: increased metabolic rate significantly (P < 0.05) increased inspired ppCO2. Decreased air flow caused small increases in inspired ppCO2. The effect of flow was more evident at metabolic rates . 2000 BTU/hr. CO2 washout values of the EM-ACES were slightly but not significantly better than those of the REI suit. Regression equations were developed for each suit to predict the mean inspired ppCO2 as a function of metabolic rate and suit flow rate. This paper provides detailed descriptions of the test hardware, methodology, and results as well as implications for future

  15. Inhomogeneity of pulmonary ventilation during sustained microgravity as determined by single-breath washouts

    NASA Technical Reports Server (NTRS)

    Guy, Harold J. B.; Prisk, G. Kim; Elliott, Ann R.; Deutschman, Robert A., III; West, John B.

    1994-01-01

    Gravity is known to cause inhomogeneity of ventilation. Nongravitational factors are also recognized, but their relative contribution is not understood. We therefore studied ventilatory inhomogeneity during sustained microgravity during the 9-day flight of Spacelab SLS-1. All seven crew members performed single-breath nitrogen washouts. They inspired a vital capacity breath of 100% oxygen with a bolus of argon at the start of inspiration, and the inspiratory and expiratory flow rates were controlled at 0.5 l/s. Control measurements in normal gravity (1 G) were made pre- and postflight in the standing and supine position. Compared with the standing 1-G measurements, there was a marked decrease in ventilatory inhomogeneity during microgravity, as evidenced by the significant reductions in cardiogenic oscillations, slope of phase III, and height of phase IV for nitrogen and argon. However, argon phase IV volume was not reduced, and considerable ventilatory inhomogeneity remained. For example, the heights of the cardiogenic oscillations during microgravity for nitrogen and argon were 44 and 24%, respectively, of their values at 1 G, whereas the slopes of phase III for nitrogen and argon were 78 and 29%, respectively, of those at 1 G. The presence of a phase IV in microgravity is strong evidence that airway closure still occurs in the absence of gravity. The results were qualitatively similar to those found previously during short periods of 0 G in parabolic flight.

  16. Optical spectroscopy of the bladder washout fluid to optimize fluorescence cystoscopy with Hexvix®

    NASA Astrophysics Data System (ADS)

    Martoccia, Carla; Zellweger, Matthieu; Lovisa, Blaise; Jichlinski, Patrice; van den Bergh, Hubert; Wagnières, Georges

    2014-09-01

    Fluorescence cystoscopy enhances detection of early bladder cancer. Water used to inflate the bladder during the procedure rapidly contains urine, which may contain fluorochromes. This frequently degrades fluorescence images. Samples of bladder washout fluid (BWF) or urine were collected (15 subjects). We studied their fluorescence properties and assessed changes induced by pH (4 to 9) and temperature (15°C to 41°C). A typical fluorescence spectrum of BWF features a main peak (excitation/emission: 320/420 nm, FWHM=50/100 nm) and a weaker (5% to 20% of main peak intensity), secondary peak (excitation/emission: 455/525 nm, FWHM=80/50 nm). Interpatient fluctuations of fluorescence intensity are observed. Fluorescence intensity decreases when temperature increases (max 30%) or pH values vary (max 25%). Neither approach is compatible with clinical settings. Fluorescence lifetime measurements suggest that 4-pyridoxic acid/riboflavin is the most likely molecule responsible for urine's main/secondary fluorescence peak. Our measurements give an insight into the spectroscopy of the detrimental background fluorescence. This should be included in the optical design of fluorescence cystoscopes. We estimate that restricting the excitation range from 370-430 nm to 395-415 nm would reduce the BWF background by a factor 2.

  17. Rapid radiotracer washout from the heart: effect on image quality in SPECT performed with a single-headed gamma camera system.

    PubMed

    O'Connor, M K; Cho, D S

    1992-06-01

    Technetium-99m-teboroxime demonstrates high extraction and rapid washout from the myocardium. To evaluate the feasibility of performing SPECT with this agent using a single-headed gamma camera system, a series of phantom studies were performed that simulated varying degrees of washout from normal and "ischemic" regions of the myocardium. In the absence of ischemic regions, short axis profiles were relatively unaffected by washout of less than 50% of activity over the duration of a SPECT acquisition. However, significant corruption of the SPECT data was observed when large (greater than a factor of 2) differences existed in the washout of activity from normal and "ischemic" myocardium. This corruption was observed with 30%-40% washout of activity from normal regions of the heart. Based on published washout rates, these results indicate that clinical studies with 99mTc-teboroxime may need to be completed within 2-4 min to order to prevent degradation of image quality due to differential washout effects.

  18. Special report on the data collection programs for the ground based nitrogen washout experiment. Volume 1: User's guide

    NASA Technical Reports Server (NTRS)

    Bueker, P. A.

    1982-01-01

    The Nitrogen Washout System measures nitrogen elimination on a breath basis from the body tissues of a subject breathing pure oxygen. The system serves as a prototype for a Space Shuttle Life Sciences experiment and in the Environmental Physiology Laboratory. Typically, a subject washes out body nitrogen for three hours while breathing oxygen from a mask enclosed in a positive-pressure oxygen tent. A nitrogen washout requires one test operator and the test subject. A DEC LSI-11/02 computer is used to (1) control and calibrate the mass spectrometer and Skylab spirometer, (2) gather and store experimental data and (3) provide limited real time analysis and more extensive post-experiment analysis. Five programs are used to gather and store the experimental data and perform all the real time control and analysis.

  19. Technical Note: Implementation of biological washout processes within GATE/GEANT4—A Monte Carlo study in the case of carbon therapy treatments

    SciTech Connect

    Martínez-Rovira, I. Jouvie, C.; Jan, S.

    2015-04-15

    Purpose: The imaging of positron emitting isotopes produced during patient irradiation is the only in vivo method used for hadrontherapy dose monitoring in clinics nowadays. However, the accuracy of this method is limited by the loss of signal due to the metabolic decay processes (biological washout). In this work, a generic modeling of washout was incorporated into the GATE simulation platform. Additionally, the influence of the washout on the β{sup +} activity distributions in terms of absolute quantification and spatial distribution was studied. Methods: First, the irradiation of a human head phantom with a {sup 12}C beam, so that a homogeneous dose distribution was achieved in the tumor, was simulated. The generated {sup 11}C and {sup 15}O distribution maps were used as β{sup +} sources in a second simulation, where the PET scanner was modeled following a detailed Monte Carlo approach. The activity distributions obtained in the presence and absence of washout processes for several clinical situations were compared. Results: Results show that activity values are highly reduced (by a factor of 2) in the presence of washout. These processes have a significant influence on the shape of the PET distributions. Differences in the distal activity falloff position of 4 mm are observed for a tumor dose deposition of 1 Gy (T{sub ini} = 0 min). However, in the case of high doses (3 Gy), the washout processes do not have a large effect on the position of the distal activity falloff (differences lower than 1 mm). The important role of the tumor washout parameters on the activity quantification was also evaluated. Conclusions: With this implementation, GATE/GEANT 4 is the only open-source code able to simulate the full chain from the hadrontherapy irradiation to the PET dose monitoring including biological effects. Results show the strong impact of the washout processes, indicating that the development of better models and measurement of biological washout data are

  20. Anticontrol of Hopf Bifurcation and Control of Chaos for a Finance System through Washout Filters with Time Delay

    PubMed Central

    Lu, Mengxia; Zuo, Junmei

    2014-01-01

    A controlled model for a financial system through washout-filter-aided dynamical feedback control laws is developed, the problem of anticontrol of Hopf bifurcation from the steady state is studied, and the existence, stability, and direction of bifurcated periodic solutions are discussed in detail. The obtained results show that the delay on price index has great influences on the financial system, which can be applied to suppress or avoid the chaos phenomenon appearing in the financial system. PMID:24977239

  1. Anticontrol of Hopf bifurcation and control of chaos for a finance system through washout filters with time delay.

    PubMed

    Zhao, Huitao; Lu, Mengxia; Zuo, Junmei

    2014-01-01

    A controlled model for a financial system through washout-filter-aided dynamical feedback control laws is developed, the problem of anticontrol of Hopf bifurcation from the steady state is studied, and the existence, stability, and direction of bifurcated periodic solutions are discussed in detail. The obtained results show that the delay on price index has great influences on the financial system, which can be applied to suppress or avoid the chaos phenomenon appearing in the financial system.

  2. Development and Validation of a Space Suit Helmet Carbon Dioxide Washout Measurement System

    NASA Technical Reports Server (NTRS)

    Bekdash, O.; Norcross, J.; Meginnis, I.; Ploutz-Snyder, R.; Korona, F. A.; Abercromby, A. F. J.

    2017-01-01

    Providing adequate washout of carbon dioxide (CO2) from within a space suit helmet is essential to maintaining a safe operating environment for astronauts using space suits. A valid and reliable method for quantification of inspired CO2 inside space suits is required to ensure the health and performance of suited crewmembers. With this objective, several different methods for measuring the concentration of CO2 in a space suit helmet were evaluated. A nasal cannula was compared with respirator style masks worn by suited test subjects, with air drawn into gas analyzers to measure the concentration of CO2 in the immediate vicinity of the mouth and nose. The respirator style masks, some being commercially available products and some novel designs, did not provide repeatable results based on initial pilot testing in three subjects. Based on the analysis of those studies, the decision was made to down-select to a commercially available nasal cannula as the primary sampling device to be used in follow-on testing in the MKIII (n = 8) and Z2 (n = 6) prototype space suits, with five subjects performing tests in both suits allowing for repeated measures comparisons. Subjects were tasked with achieving target metabolic rates of 293, 586, and 879 Watts (1000, 2000, and 3000 BTU/h) and at air supply flow rates of 3.4, 6.8, and 10.2 Am(sup 3)/hr. (2, 4, and 6 ACFM). Each test condition was performed twice; once with subjects instructed to breathe however they felt comfortable, and once with subjects instructed to breathe only through their nose. Inspired CO2 values were determined by the lowest points, or troughs, within each breath of the respiratory trace. This method provides multiple inspired CO2 samples at known metabolic rates for each test condition and provides a larger data set for analysis than possible through gross averaging of the minimum inspired CO2. Results indicate that reliable measures are achievable under both breathing conditions but that restricting subjects

  3. [Measurement of functional residual capacity by nitrogen washout during mechanical ventilation].

    PubMed

    Nomura, T; Saito, Y; Ogawa, H; Akata, N; Nishino, Y; Kosaka, Y

    1998-02-01

    A medical gas analyzer AMIS 2000 SP, which is a mass spectrometer, incorporating a fractional residual capacity (FRC) measuring program based on a nitrogen washout method, has been introduced recently. The purpose of this study was to assess the reliability and the reproductivity of the FRC measuring system in a clinical situation. FRC was measured by this system connected to a ventilator (Bennet 7200ae). Our study examined; 1) the accuracy of the measurement using a syringe. 2) the difference in two consecutive measurements in the same subject during mechanical ventilation, and 3) the correlation between the measured and the predicted value calculated with Gorldman's formula in 18 subjects during ventilation. The first study has showed an excellent correlation (y = 0.953x + 0.092, r = 0.996, P < 0.001) or y = 0.909x + 0.132 (r = 0.999, P < 0.001) with a tidal volume of 400 ml or 500 ml, respectively) between the measured value and the syringe capacity. Reproductivity was proved by the linear regression (y = 0.977x + 0.024, r = 0.998, P < 0.001) between the two consecutive measurements. A good correlation was shown between the measured values and the predicted values (y = 0.656x - 0.415, r = 0.849, P < 0.0001). These results showed good reliability and reproductivity of our FRC measuring system. It is concluded that the FRC measurements using AMIS2000SP system can be used in clinical respiratory managements in ICU.

  4. A Functional Mathematical Model to Simulate the Single-Breath Nitrogen Washout

    PubMed Central

    Barbini, Paolo; Brighenti, Chiara; Gnudi, Gianni

    2013-01-01

    A nonlinear dynamic model is proposed to reproduce and interpret the influence of pulmonary inhomogeneities on the single-breath nitrogen washout (SBNW) curve. The model is characterized by two parallel zones. In each zone, the upper airways are described by a Rohrer resistor. Intermediate airways are represented as a collapsible segment, the volume of which depends on transmural pressure. Smaller airways are described by a resistance which increases when transpulmonary pressure decreases. The respiratory region is modeled as a Voigt element. Three different conditions were simulated: a reference case, characterized by airway-parameter values for normal conditions, and two pathological states corresponding to different levels of disease. In the reference case, a straight line was a good approximation of SBNW phase III and the last point of departure of the nitrogen trace from this line unambiguously identified the onset of phase IV. The slope of phase III rose with disease severity (from a 1.1% increase in nitrogen concentration per 1000 ml of expired volume in the reference case to 3.6% and 7.7% in the pathological cases) and the distinction between phases III and IV became less evident. The results obtained indicate that the slope of phase III depends primarily on nitrogen-concentration differences between lung zones, as determined by different mechanical properties of the respiratory airways. In spite of the simplified representation of the lungs, the similarity of the simulation results to actual data suggests that the proposed model describes important physiological mechanisms underlying changes observed during SBNW in normal and pathological patients. PMID:24044025

  5. Diagnosis of vasculogenic impotence: Combination of penile xenon-133 washout and papaverine tests

    SciTech Connect

    Lin, S.N.; Liu, R.S.; Yu, P.C.; Chang, L.S.; Yeh, S.H.; Kuo, J.S.

    1989-07-01

    The present study evaluates both penile xenon-133 washout (XWT) and papaverine tests (PT) in the diagnosis of vasculogenic impotence. XWT was accomplished by subcutaneous injection of xenon-133 (1-2 mCi in 0.1 mL saline solution) into the dorsal coronal prepuce. Abnormal XWT was suggested in patients whose clearance time (T1/2) was longer than 7.5 minutes and whose penile blood flow rate (Q) was less than 6 mL/100 g tissue/min. PT was done by intracavernous injection of papaverine (60 mg in 20 mL normal saline). Abnormal PT was indicated in patients whose onset of full erection was more than ten minutes after papaverine injection and whose duration of erection was less than one hour. Ten young and 11 older normal volunteers were examined with XWT only; all showed normal results. A total of 60 impotent patients were examined with both XWT and PT and were classified into four groups: in 2 patients (3.3%) both XWT and PT were normal (group I); in 8 (13.3%) XWT was abnormal and PT normal (group II); in 14 (23.3%) XWT was normal and PT abnormal (group III); and in 36 (60%) both XWT and PT were abnormal (group IV). On further examination with bilateral hypogastric arteriography in 10 XWT-abnormal patients and on surgical correction of abnormal curvature in 5 XWT-abnormal patients, all (100%) were proved to have penile arterial insufficiency. Erection cavernosography performed in 15 PT-abnormal patients confirmed penile venous insufficiency in 80 percent. We conclude both XWT and PT are simple and effective for evaluation of the penile arterial blood flow and venous competence, respectively.

  6. A Realistic Validation Study of a New Nitrogen Multiple-Breath Washout System

    PubMed Central

    Singer, Florian; Houltz, Birgitta; Latzin, Philipp; Robinson, Paul; Gustafsson, Per

    2012-01-01

    Background For reliable assessment of ventilation inhomogeneity, multiple-breath washout (MBW) systems should be realistically validated. We describe a new lung model for in vitro validation under physiological conditions and the assessment of a new nitrogen (N2)MBW system. Methods The N2MBW setup indirectly measures the N2 fraction (FN2) from main-stream carbon dioxide (CO2) and side-stream oxygen (O2) signals: FN2 = 1−FO2−FCO2−FArgon. For in vitro N2MBW, a double chamber plastic lung model was filled with water, heated to 37°C, and ventilated at various lung volumes, respiratory rates, and FCO2. In vivo N2MBW was undertaken in triplets on two occasions in 30 healthy adults. Primary N2MBW outcome was functional residual capacity (FRC). We assessed in vitro error (√[difference]2) between measured and model FRC (100–4174 mL), and error between tests of in vivo FRC, lung clearance index (LCI), and normalized phase III slope indices (Sacin and Scond). Results The model generated 145 FRCs under BTPS conditions and various breathing patterns. Mean (SD) error was 2.3 (1.7)%. In 500 to 4174 mL FRCs, 121 (98%) of FRCs were within 5%. In 100 to 400 mL FRCs, the error was better than 7%. In vivo FRC error between tests was 10.1 (8.2)%. LCI was the most reproducible ventilation inhomogeneity index. Conclusion The lung model generates lung volumes under the conditions encountered during clinical MBW testing and enables realistic validation of MBW systems. The new N2MBW system reliably measures lung volumes and delivers reproducible LCI values. PMID:22558338

  7. The washout effect during laundry on benzothiazole, benzotriazole, quinoline, and their derivatives in clothing textiles.

    PubMed

    Luongo, Giovanna; Avagyan, Rozanna; Hongyu, Ren; Östman, Conny

    2016-02-01

    In two previous papers, the authors have shown that benzothiazole, benzotriazole, quinoline, and several of their derivatives are widespread in clothing textile articles. A number of these compounds exhibit allergenic and irritating properties and, due to their octanol-water partition coefficient, are prone to be absorbed by the skin. Moreover, they are slightly soluble in water, which could make washing of clothes a route of emission into the environment. In the present study, the washout effect of benzothiazole, benzotriazole, quinoline, and some of their derivatives has been investigated. Twenty-seven textile samples were analyzed before, as well as after five and ten times of washing. The most abundant analyte was found to be benzothiazole, which was detected in 85 % of the samples with an average concentration of 0.53 μg/g (median 0.44 μg/g), followed by quinoline, detected in 81 % of the samples with an average concentration of 2.42 μg/g (median 0.21 μg/g). The average decrease in concentration for benzothiazoles was 50 % after ten times washing, while it was around 20 % for quinolines. The average emission to household wastewater of benzothiazoles and quinolines during one washing (5 kg of clothes made from polyester materials) was calculated to 0.5 and 0.24 g, respectively. These results strongly indicate that laundering of clothing textiles can be an important source of release of these compounds to household wastewater and in the end to aquatic environments. It also demonstrates a potential source of human exposure to these chemicals since considerable amounts of the compounds remain in the clothes even after ten times of washing.

  8. The washout effect during laundry on benzothiazole, benzotriazole, quinoline, and their derivatives in clothing textiles.

    PubMed

    Luongo, Giovanna; Avagyan, Rozanna; Hongyu, Ren; Östman, Conny

    2016-02-01

    In two previous papers, the authors have shown that benzothiazole, benzotriazole, quinoline, and several of their derivatives are widespread in clothing textile articles. A number of these compounds exhibit allergenic and irritating properties and, due to their octanol-water partition coefficient, are prone to be absorbed by the skin. Moreover, they are slightly soluble in water, which could make washing of clothes a route of emission into the environment. In the present study, the washout effect of benzothiazole, benzotriazole, quinoline, and some of their derivatives has been investigated. Twenty-seven textile samples were analyzed before, as well as after five and ten times of washing. The most abundant analyte was found to be benzothiazole, which was detected in 85 % of the samples with an average concentration of 0.53 μg/g (median 0.44 μg/g), followed by quinoline, detected in 81 % of the samples with an average concentration of 2.42 μg/g (median 0.21 μg/g). The average decrease in concentration for benzothiazoles was 50 % after ten times washing, while it was around 20 % for quinolines. The average emission to household wastewater of benzothiazoles and quinolines during one washing (5 kg of clothes made from polyester materials) was calculated to 0.5 and 0.24 g, respectively. These results strongly indicate that laundering of clothing textiles can be an important source of release of these compounds to household wastewater and in the end to aquatic environments. It also demonstrates a potential source of human exposure to these chemicals since considerable amounts of the compounds remain in the clothes even after ten times of washing. PMID:26429136

  9. Reproducibility of multiple breath washout indices in the unsedated preterm neonate.

    PubMed

    Sinhal, Sanjay; Galati, John; Baldwin, David N; Stocks, Janet; Pillow, J Jane

    2010-01-01

    Multiple breath inert gas washout (MBW) is gaining popularity for measurements of resting lung volume and ventilation inhomogeneity. Test reproducibility is an important determinant of the clinical applicability of diagnostic tests. The between-test reproducibility of variables derived from MBW tests in newborn infants is unknown. We aimed to determine the within-test repeatability and short-term between-test reproducibility of MBW variables in unsedated preterm infants. We hypothesized that measurements obtained within a 3-day interval in clinically stable preterm infants would be reproducible and suitable for use as an objective clinical outcome measurement. In this cross-sectional observational study, clinically stable hospitalized preterm infants whose parents had given informed consent for MBW studies were tested twice within 72 hr during quiet, unsedated sleep. Functional residual capacity (FRC), lung clearance index (LCI), and the first and second to zeroeth moment ratios (M(1):M(0); M(2):M(0)) were computed from MBW traces obtained using a mainstream ultrasonic flowmeter and 4% sulphur hexafluoride (MBW(SF6)). Within-test repeatability and between-test reproducibility were determined. Within-test repeatability (expressed as a coefficient of variability (C(v))) for differences between two and four replicate measurements on the same test occasion, were 9.3% (FRC), 9.0% (LCI), 7.6% (M(1):M(0)), and 15.6% (M(2):M(0)), respectively. The within-test C(v)'s were not statistically different to the between-tests C(v)'s, which were 7.7% (FRC), 10.3% (LCI), 6.1% (M(1):M(0)), and 13.0% (M(2):M(0)), respectively. Among unsedated preterm infants, between-test reproducibility over a 3-day interval was similar to within-test repeatability. The wide limits of agreement may limit the application of these measures to detect a clinically significant change in condition in small preterm infants. PMID:20025050

  10. Fast washout of TL-201 from infarct area: Sign of reestablished coronary blood flow

    SciTech Connect

    Wackers, F.J.; Brown, K.A.; Clements, J.P.

    1985-05-01

    Relative fast (F) washout (WO) of Tl-201 from an area of myocardial infarction (MI) occasionally can be demonstrated by quantitative analysis of exercise (EX) scans. Recently FWO was reported in predischarge EX-Tl-201 scans in patients (PTS) who had thrombolysis in evolving acute MI. It was suggested that FWO indicated reestablished blood flow to the MI region. Since thrombolysis may also occur spontaneously, we tested the hypothesis that when FWO occurs in PTS with natural course of prior MI, the infarct coronary artery is patent. Of 150 consecutive PTS who had quantitative EX-Tl-201 scans and coronary angiography (CA), 71 PTS had prior Q-wave MI on ECG. In normal subjects, Tl-201 WO is almost uniform throughout the heart and mean (+- SD) variability is 17 +- 7%. FWO is defined as WO in MI area exceeding mean variability + SD (=32%) compared to WO in adjacent normal myocardium. Of 71 PTS with MI, FWO occurred in 9 (12%) PTS. Mean WO in MI areas was 64 +- 15% vs 36 +- 9% (p<0.01) in normal myocardium. Of the remaining 62 PTS, 37 had normal WO (fixed defect), 25 had low WO (partial filling-in). Of 9 PTS with FWO, 8 had 100% stenosis of infarct vessel on CA; one PT had 90% stenosis. All 9 PTS had moderate to severe left ventricular regional wall motion abnormality. Thus, 1) FWO appears not to be related to reestablish flow, as evidenced by persistent coronary artery occlusion and regional dysfunction, 2) Alternative pathophysiologic explanation for FWO should be considered. However, artefactual increase of calculated WO on the basis of interpolative background correction may provide a potential simple explanation.

  11. In vitro and in vivo studies of boron neutron capture therapy: boron uptake/washout and cell death.

    PubMed

    Ferrari, C; Bakeine, J; Ballarini, F; Boninella, A; Bortolussi, S; Bruschi, P; Cansolino, L; Clerici, A M; Coppola, A; Di Liberto, R; Dionigi, P; Protti, N; Stella, S; Zonta, A; Zonta, C; Altieri, S

    2011-04-01

    Boron neutron capture therapy (BNCT) is a binary radiotherapy based on thermal-neutron irradiation of cells enriched with (10)B, which produces α particles and (7)Li ions of short range and high biological effectiveness. The selective uptake of boron by tumor cells is a crucial issue for BNCT, and studies of boron uptake and washout associated with cell survival studies can be of great help in developing clinical applications. In this work, boron uptake and washout were characterized both in vitro for the DHDK12TRb (DHD) rat colon carcinoma cell line and in vivo using rats bearing liver metastases from DHD cells. Despite a remarkable uptake, a large boron release was observed after removal of the boron-enriched medium from in vitro cell cultures. However, analysis of boron washout after rat liver perfusion in vivo did not show a significant boron release, suggesting that organ perfusion does not limit the therapeutic effectiveness of the treatment. The survival of boron-loaded cells exposed to thermal neutrons was also assessed; the results indicated that the removal of extracellular boron does not limit treatment effectiveness if adequate amounts of boron are delivered and if the cells are kept at low temperature. Cell survival was also investigated theoretically using a mechanistic model/Monte Carlo code originally developed for radiation-induced chromosome aberrations and extended here to cell death; good agreement between simulation outcomes and experimental data was obtained.

  12. In vitro and in vivo studies of boron neutron capture therapy: boron uptake/washout and cell death.

    PubMed

    Ferrari, C; Bakeine, J; Ballarini, F; Boninella, A; Bortolussi, S; Bruschi, P; Cansolino, L; Clerici, A M; Coppola, A; Di Liberto, R; Dionigi, P; Protti, N; Stella, S; Zonta, A; Zonta, C; Altieri, S

    2011-04-01

    Boron neutron capture therapy (BNCT) is a binary radiotherapy based on thermal-neutron irradiation of cells enriched with (10)B, which produces α particles and (7)Li ions of short range and high biological effectiveness. The selective uptake of boron by tumor cells is a crucial issue for BNCT, and studies of boron uptake and washout associated with cell survival studies can be of great help in developing clinical applications. In this work, boron uptake and washout were characterized both in vitro for the DHDK12TRb (DHD) rat colon carcinoma cell line and in vivo using rats bearing liver metastases from DHD cells. Despite a remarkable uptake, a large boron release was observed after removal of the boron-enriched medium from in vitro cell cultures. However, analysis of boron washout after rat liver perfusion in vivo did not show a significant boron release, suggesting that organ perfusion does not limit the therapeutic effectiveness of the treatment. The survival of boron-loaded cells exposed to thermal neutrons was also assessed; the results indicated that the removal of extracellular boron does not limit treatment effectiveness if adequate amounts of boron are delivered and if the cells are kept at low temperature. Cell survival was also investigated theoretically using a mechanistic model/Monte Carlo code originally developed for radiation-induced chromosome aberrations and extended here to cell death; good agreement between simulation outcomes and experimental data was obtained. PMID:21133762

  13. Reverse and pseudo redistribution of thallium-201 in healed myocardial infarction and normal and negative thallium-201 washout in ischemia due to background oversubtraction

    SciTech Connect

    Lear, J.L.; Raff, U.; Jain, R.

    1988-09-15

    While the interpolative background subtraction used in quantitative planar thallium scanning can significantly overestimate the background overlying the heart, the effects of background oversubtraction on quantitative analysis have not been well defined. A mathematical model that relates myocardial washout determined using interpolative background subtraction to true myocardial washout is presented. The model was validated using phantoms and applied to myocardial and pulmonary thallium kinetic data in 100 patients, 85 with and 15 without coronary artery disease. The model showed that when using interpolative background subtraction, measured washout equals true washout in normally perfused myocardium; however, depending on the relation between myocardial and pulmonary thallium clearance, myocardial washout in ischemic regions and areas of infarction can be substantially over- or underestimated. Based on generally accepted quantitative criteria, this incorrect washout determination can at times lead to misdiagnosis of infarction as ischemia and ischemia as normally perfused tissue. It can also cause both ''reverse redistribution'' and ''pseudo redistribution'' of thallium in myocardial infarction in the absence of a physiologic basis.

  14. The risk of river pollution due to washout from contaminated floodplain water bodies during periods of high magnitude floods

    NASA Astrophysics Data System (ADS)

    Lyubimova, T.; Lepikhin, A.; Parshakova, Ya.; Tiunov, A.

    2016-03-01

    The risk of river pollution due to washout (removal of pollutants) from contaminated floodplain water bodies (floodplain lakes and quarries whose origin is related to the large-scale mining of nonmetallic building materials in the floodplain zone) during high magnitude flood periods is analyzed using a combination of one-, two- and three-dimensional hydrodynamic modeling and in situ measurements. The modeling performed for the floodplain water bodies contaminated by N compounds shows that during large magnitude floods washout occurs. The washout process consists of two stages: an initial rapid stage lasting about two hours during which the upper (3-4 m thick) layer is washed out, followed by a second stage when the concentration of NH4-N in the floodplain water body remains nearly constant. The maximum contaminant concentration in the river in the vicinity of a water intake for drinking water located 21 km downstream is attained about 9 h from the beginning of the flood; concentration of NH4-N can reach values several times larger than acceptable concentration guidelines. The initial primary peak in contaminant concentration at the water intake is followed by a slight decrease in contaminant concentration; a second peak related to the contaminant transport through the inundated floodplain subsequently occurs, after which the concentration slowly decreases, reaching acceptable values after 30-40 h. Contaminated floodplain water bodies located near drinking water supply systems are not significant sources of contamination during small and moderate floods, but during high magnitude floods, they can become sources of water pollution. Operational measures that can decrease potential health risks are discussed.

  15. Uptake and washout of borocaptate sodium and borono-phenylalanine in cultured melanoma cells: a multi-nuclear NMR study.

    PubMed

    Panov, V; Salomon, Y; Kabalka, G W; Bendel, P

    2000-07-01

    The cellular uptake and washout of the two principal boron neutron capture therapy (BNCT) agents, borocaptate sodium (BSH) and borono-phenylalanine (BPA), were monitored on-line, noninvasively, using nuclear magnetic resonance (NMR) spectroscopy. The uptake and washout of inorganic borate (B(i)) was also followed for comparison. M2R mouse melanoma cells grown on polystyrene microspheres were perfused inside the NMR sample tube. (11)B NMR was used to detect the presence of B(i), BSH and BPA, and (19)F NMR was applied to detect fluorinated BPA ((19)F-BPA). The results revealed chemical modifications of BSH due to spontaneous formation of the borocaptate dimer, BSSB, in the culture medium. BPA readily formed a complex with glucose contained in the culture medium but was also converted in the cells to a yet unidentified compound in a reaction that probably involves the hydrolysis of BPA and the release of B(i). The cellular accumulation ratio for BPA was significantly higher than 1 and was also significantly higher than that for BSH. On the other hand, the cellular retention time observed for BSH was much longer than for BPA, indicating a strong trapping of BSH in cells.

  16. Results from Carbon Dioxide Washout Testing Using a Suited Manikin Test Apparatus with a Space Suit Ventilation Test Loop

    NASA Technical Reports Server (NTRS)

    Chullen, Cinda; Conger, Bruce; McMillin, Summer; Vonau, Walt; Kanne, Bryan; Korona, Adam; Swickrath, Mike

    2016-01-01

    NASA is developing an advanced portable life support system (PLSS) to meet the needs of a new NASA advanced space suit. The PLSS is one of the most critical aspects of the space suit providing the necessary oxygen, ventilation, and thermal protection for an astronaut performing a spacewalk. The ventilation subsystem in the PLSS must provide sufficient carbon dioxide (CO2) removal and ensure that the CO2 is washed away from the oronasal region of the astronaut. CO2 washout is a term used to describe the mechanism by which CO2 levels are controlled within the helmet to limit the concentration of CO2 inhaled by the astronaut. Accumulation of CO2 in the helmet or throughout the ventilation loop could cause the suited astronaut to experience hypercapnia (excessive carbon dioxide in the blood). A suited manikin test apparatus (SMTA) integrated with a space suit ventilation test loop was designed, developed, and assembled at NASA in order to experimentally validate adequate CO2 removal throughout the PLSS ventilation subsystem and to quantify CO2 washout performance under various conditions. The test results from this integrated system will be used to validate analytical models and augment human testing. This paper presents the system integration of the PLSS ventilation test loop with the SMTA including the newly developed regenerative Rapid Cycle Amine component used for CO2 removal and tidal breathing capability to emulate the human. The testing and analytical results of the integrated system are presented along with future work.

  17. Preliminary application of dynamic pulmonary xenon-133 single-photon emission tomography in the evaluation of patients with pulmonary emphysema for thoracoscopic lung volume reduction surgery.

    PubMed

    Suga, K; Nishigauchi, K; Matsunaga, N; Matsumoto, T; Kume, N; Sugi, K; Esato, K

    1998-04-01

    Dynamic pulmonary xenon-133 single-photon emission tomography (SPET) with three-dimensional (3D) displays was preliminarily applied to select resection targets for thoracoscopic lung volume reduction surgery (LVRS) and to assess regional ventilatory changes following surgery. Dynamic SPET was performed using a triple-detector SPET system in 14 patients with pulmonary emphysema before and after LVRS. After reconstructing colour-illuminated, surface-rendered 3D images of equilibrium (EQ) and 3-min washout (WO3), a single 3D fusion display was created from these two different time-course image sets, in which the 3D WO3 image indicating 133Xe retention was visible through the overlying 3D EQ image delineating lung contours. Volumetric extent of retention on this display was quantified by a 133Xe retention index, defined as the ratio (%) of total pixel numbers of segmented 3-min WO data to those of EQ data. 133Xe SPET and appropriately thresholded 3D displays efficiently localized a total of 36 retention sites; 19 (52.7%) of these sites were not localized by CT because they were within the widely or homogeneously spreading non-bullous emphysematous lung tissues. The 3D displays enhanced the perception of anatomical configurations and the extent of 133Xe retention compared with multislice tomograms. Postoperatively, 3D fusion display visualized the details of regional changes in retention, and changes in the retention index on the 3D display with a standardized threshold correlated well with changes in 133Xe clearance time (T1/2) and %FEV1 (r = 0.881 and 0. 856, respectively; P<0.0001). This preliminary study indicates that 133Xe SPET and appropriately thresholded, topographic 3D displays are of potential use in selecting resection targets for LVRS, and in evaluating the treatment effects on regional ventilation.

  18. Association between Irrigation Fluids, Washout Volumes and Risk of Local Recurrence of Anterior Resection for Rectal Cancer: A Meta-Analysis of 427 Cases and 492 Controls

    PubMed Central

    Li, Juan; Wang, Ke; He, Jianjun; Chen, Wuke; Liu, Peijun

    2014-01-01

    Background Rectal washout can prevent local recurrence after anterior resection of rectal cancer. Few studies have focused particularly on the association between irrigation fluids volume or agents and the risk of local recurrence after anterior resection of rectal cancer. Objective To estimate the association between irrigation fluids types, volumes of rectal washout and risk of local recurrence after anterior resection for cancer. Data Sources Relevant studies were identified by a search of Medline, Embase, Wiley Online Library, China National Knowledge Infrastructure, Cochrane Oral Health Group Specialized Register, Wanfang databases and Google Website from their inception until October 18,2013. Study Selection Studies reporting the association between rectal washout types and volumes and risk of local recurrence after anterior resection for cancer were included. Interventions Eligible studies used rectal washout. Control groups were defined as no washout. Study Appraisal and Synthesis Methods Random-effects model were used to obtain summary estimates of RR and 95% CI, with Stata version 11 and RevMan 5.2.5 softwares used. The quality of report was appraised in reference to the MINORS item. Results Of the 919 rectal cancer patients in 8 included studies, a total of 61(6.64%) cases of local recurrence were reported, with a pooled RR 0.51 (95%CI = 0.28–0.92, P = 0.03). The RRs 0.37 and 0.39 in normal saline and washout volume (≥1500 ml normal saline) subgroup, respectively, indicated that rectal washout with normal saline, or ≥1500 ml in volume could significantly reduce local recurrence (LR) rate (95% CI = 0.17–0.79, P = 0.01; 95% CI = 0.18–0.87, P = 0.02) after anterior resection for cancer. Limitation The included studies were non-randomized observational studies, with diversity of study designs. Conclusion Rectal washout with normal saline alone can reduce the risk of local recurrence in patients with resectable rectal cancer

  19. Estimation of the in situ degradation of the washout fraction of starch by using a modified in situ protocol and in vitro measurements.

    PubMed

    de Jonge, L H; van Laar, H; Dijkstra, J

    2015-09-01

    The in situ degradation of the washout fraction of starch in six feed ingredients (i.e. barley, faba beans, maize, oats, peas and wheat) was studied by using a modified in situ protocol and in vitro measurements. In comparison with the washing machine method, the modified protocol comprises a milder rinsing method to reduce particulate loss during rinsing. The modified method markedly reduced the average washout fraction of starch in these products from 0.333 to 0.042 g/g. Applying the modified rinsing method, the fractional degradation rate (k d ) of starch in barley, oats and wheat decreased from on average 0.327 to 0.144 h-1 whereas for faba beans, peas and maize no differences in k d were observed compared with the traditional washing machine rinsing. For barley, maize and wheat, the difference in non-fermented starch in the residue between both rinsing methods during the first 4 h of incubation increased, which indicates secondary particle loss. The average effective degradation of starch decreased from 0.761 to 0.572 g/g when using the new rinsing method and to 0.494 g/g when applying a correction for particulate matter loss during incubation. The in vitro k d of starch in the non-washout fraction did not differ from that in the total product. The calculated ratio between the k d of starch in the washout and non-washout fraction was on average 1.59 and varied between 0.96 for oats and 2.39 for maize. The fractional rate of gas production was significantly different between the total product and the non-washout fraction. For all products, except oats, this rate of gas production was larger for the total product compared with the non-washout fraction whereas for oats the opposite was observed. The rate of increase in gas production was, especially for grains, strongly correlated with the in vitro k d of starch. The results of the present study do not support the assumption used in several feed evaluation systems that the degradation of the washout fraction of

  20. A model validation study of the washout/rainout contribution of sulfate and nitrate in wet deposition compared with precipitation chemistry data in Japan

    NASA Astrophysics Data System (ADS)

    Kajino, Mizuo; Aikawa, Masahide

    2015-09-01

    We simulated washout/rainout ratios of non-sea-salt (nss)-SO42- and NO3- using a chemical transport model and compared the estimates with precipitation measurements sampled at 0.5/1 mm intervals at sites located in Kobe (urban), Toyo-oka (suburban), and Tamba (rural) cities, Japan. The 25th and 75th percentile range of the simulated washout contributions was 30-70%. The simulated washout contribution range of NO3- (40-70%) was greater than that of nss-SO42 - (30-60%). There was good agreement between the simulated and observed values, and the observed washout contribution of NO3- was also greater than that of SO42-. The simulated washout contribution range was higher (60-75%) in emission source regions and lower (40-55%) in downwind areas. The wet deposition process is one of the key causes of uncertainty in chemical transport modeling. Comparing model results with such high-frequency precipitation chemistry data has been extremely rare. Thus the current study is providing useful information for evaluating and improving wet deposition modeling and for the better understanding of the wet deposition mechanism.

  1. Calcitonin measurement in fine-needle aspirate washouts vs. cytologic examination for diagnosis of primary or metastatic medullary thyroid carcinoma.

    PubMed

    de Crea, C; Raffaelli, M; Maccora, D; Carrozza, C; Canu, G; Fadda, G; Bellantone, R; Lombardi, C P

    2014-12-01

    Ultrasound-guided fine-needle aspiration biopsy cytology (FNAB-C) is able to detect approximately 63% of medullary thyroid carcinoma (MTC). The measurement of calcitonin in the needle washout (FNAB-CT) could improve its accuracy. Sixty-two FNAB-C were performed in 38 patients. Serum calcitonin (sCT) was measured before performing FNAB-C. After obtaining a FNAB-C specimen, the needle was washed with 0.5 ml of saline solution to obtain the CT washouts. Receiver operating characteristic (RO C) analysis identified the cut-offs of FNAB-CT and FNAB-CT/sCT. Eighteen MTC were found at final histology. RO C analysis indicated FNAB-CT > 10.4 pg/ml and FNABCT/ sCT > 1.39 as more accurate cut-off values. Overall accuracy, positive (PPV) and negative predictive values (NPV) were 85%, 100 and 83%, respectively, for FNAB-C, 97%, 100%, 96% for FNAB-CT and 90%, 83% and 93% for FNAB-CT/sCT. The integration of FNAB-C and FNAB-CT resulted in 98% overall accuracy, 100% PPV and 98% NPV; the integration of FNAB-C and FNAB-CT/sCT in 90% overall accuracy, 80% PPV and 95% NPV. One of 2 false negative FNAB-CT and one of 3 false negative FNAB CT/sCT were correctly diagnosed by FNAB-C. Eight of 9 non-diagnostic FNAB-C were correctly classified by FNAB-CT and 7 by FNAB CT/sCT. FNAB-CT should integrate but not replace FNAB-C. FNAB-CT is particularly useful in the presence of non-diagnostic FNAB-C.

  2. A new double-tracer gas single-breath washout to assess early cystic fibrosis lung disease.

    PubMed

    Singer, Florian; Stern, Georgette; Thamrin, Cindy; Abbas, Chiara; Casaulta, Carmen; Frey, Urs; Latzin, Philipp

    2013-02-01

    In cystic fibrosis (CF), tests for ventilation inhomogeneity are sensitive but not established for clinical routine. We assessed feasibility of a new double-tracer gas single-breath washout (SBW) in school-aged children with CF and control subjects, and compared SBW between groups and with multiple-breath nitrogen washout (MBNW). Three SBW and MBNW were performed in 118 children (66 with CF) using a side-stream ultrasonic flowmeter setup. The double-tracer gas containing 5% sulfur hexafluoride and 26.3% helium was applied during one tidal breath. Outcomes were SBW phase III slope (SIII(DTG)), MBNW-derived lung clearance index (LCI), and indices of acinar (S(acin)) and conductive (S(cond)) ventilation inhomogeneity. SBW took significantly less time to perform than MBNW. SBW and MBNW were feasible in 109 (92.4%) and 98 (83.0%) children, respectively. SIII(DTG) differed between children with CF and controls, mean±sd was -456.7±492.8 and -88.4±129.1 mg·mol·L(-1), respectively. Abnormal SIII(DTG) was present in 36 (59%) children with CF. SIII(DTG) was associated with LCI (r= -0.58) and S(acin) (r= -0.58), but not with S(cond). In CF, steeply sloping SIII(DTG) potentially reflects ventilation inhomogeneity near the acinus entrance. This tidal SBW is a promising test to assess ventilation inhomogeneity in an easy and fast way. PMID:22599360

  3. High frequency jet ventilation and intermittent positive pressure ventilation. Effect of cerebral blood flow in patients after open heart surgery

    SciTech Connect

    Pittet, J.F.; Forster, A.; Suter, P.M. )

    1990-02-01

    Attenuation of ventilator-synchronous pressure fluctuations of intracranial pressure has been demonstrated during high frequency ventilation in animal and human studies, but the consequences of this effect on cerebral blood flow have not been investigated in man. We compared the effects of high frequency jet ventilation and intermittent positive pressure ventilation on CBF in 24 patients investigated three hours after completion of open-heart surgery. The patients were investigated during three consecutive periods with standard sedation (morphine, pancuronium): a. IPPV; b. HFJV; c. IPPV. Partial pressure of arterial CO{sub 2} (PaCO{sub 2}: 4.5-5.5 kPa) and rectal temperature (35.5 to 37.5{degree}C) were maintained constant during the study. The CBF was measured by intravenous {sup 133}Xe washout technique. The following variables were derived from the cerebral clearance of {sup 133}Xe: the rapid compartment flow, the initial slope index, ie, a combination of the rapid and the slow compartment flows, and the ratio of fast compartment flow over total CBF (FF). Compared to IPPV, HFJV applied to result in the same mean airway pressure did not produce any change in pulmonary gas exchange, mean systemic arterial pressure, and cardiac index. Similarly, CBF was not significantly altered by HFJV. However, important variations of CBF values were observed in three patients, although the classic main determinants of CBF (PaCO{sub 2}, cerebral perfusion pressure, Paw, temperature) remained unchanged. Our results suggest that in patients with normal systemic hemodynamics, the effects of HFJV and IPPV on CBF are comparable at identical levels of mean airway pressure.

  4. Special Report on the Data Collection Programs for the Ground Based Nitrogen Washout Experiment. Volume 2 - Detailed Program Descriptions, Listings, Examples and Hardware Specifications

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Personal data input, decompression data, nitrogen washout, nitrogen data, and update computer programs are described. Input data and formats; program output, reports, and data; program flowcharts; program listings; sample runs with input and output pages; hardware operation; and engineering data are provided.

  5. Regional comparison of technetium-99m DTPA aerosol and radioactive gas ventilation (xenon and krypton) studies in patients with suspected pulmonary embolism

    SciTech Connect

    Ramanna, L.; Alderson, P.O.; Waxman, A.D.; Berman, D.S.; Brachman, M.B.; Kroop, S.A.; Goldsmith, M.; Tanasescu, D.E.

    1986-09-01

    The regional distribution of (99mTc)DTPA aerosol was compared with that of /sup 133/Xe (n = 30) and krypton (n = 24) in a group of patients with suspected pulmonary embolism. All patients had an aerosol study using a recently available commercial generator system, a ventilation study with one of the gases, and perfusion imaging. Regional information was assessed visually on xenon, krypton, and aerosol studies independently by considering each lung as three equal-sized zones. In addition, gas ventilation findings peripheral to regions of aerosol turbulence (hot spots) were evaluated. Only 64% of the zones were in complete agreement on xenon and aerosol. Most of the discordance between xenon and aerosol was accounted for by minor degrees of /sup 133/Xe washout retention in zones that appeared normal in the aerosol study. An agreement rate of 85% was noted between 81mKr and aerosol regionally. The regions of discordance between aerosol and gas studies, however, usually were associated with unimpressive perfusion defects that did not change the scintigraphic probability for pulmonary embolism in any patient. Regarding zones of aerosol hyperdeposition, 76% had associated washout abnormalities on xenon; however, there was no correlation between the presence of these abnormalities or perfusion abnormalities. The results confirm the high sensitivity of /sup 133/Xe washout imaging, but suggest that radioaerosol imaging will detect most parenchymal abnormalities associated with perfusion defects of significance.

  6. Risk assessment for the Explosive Washout Lagoons (Site 4), Umatilla Depot Activity Hermiston, Oregon. Final report, Mar 91-Mar 92

    SciTech Connect

    Leinbach, A.; Enright, A.M.; Eaton, W.; Lemont, S.

    1992-03-01

    This document is the Risk Assessment (RA) for the Explosive Washout Lagoons (Site 4) at Umatilla Army Depot Activity (UMDA). The purpose of this RA is to address the potential future health risks posed by explosives-contaminated soil and groundwater associated with Site 4 in the absence of remediation, and to identify safe residual explosives concentrations (remedial action criteria) in soil if remediation is determined to be a requirement. This RA is not intended to address the remediation of contaminated groundwater; contaminated groundwater is addressed only to the extent that contaminants in Site 4 soil are affecting groundwater quality. The potential remediation of contaminated groundwater will be addressed in the installation-wide Baseline RA for UMDA. Based on the available data, explosives contamination appears to be widespread in soil near the lagoons and in groundwater at distances of over 650 yards from the lagoons. Three future land use scenarios-residential, light industrial, and military-and four potential future exposure pathways-soil ingestion, dust inhalation, dermal contact with soil, and groundwater ingestion-were evaluated in the RA to estimate potential future carcinogenic hazards. The results of RA indicate that remediation may be a requirement for soil at Site 4; therefore, remedial action criteria for soil were developed.

  7. Use of arterial to equilibrium enhancement washout to predict viability in liver cancers treated with transcatheter arterial chemoembolization

    NASA Astrophysics Data System (ADS)

    Choi, Seung Joon; Kim, Hyung Sik; Kim, Jeong Ho; Choi, Hye Young; Park, Hyunjin

    2013-04-01

    Liver cancers are very common in Korea and Computed Tomography (CT) imaging is commonly used to diagnose them. This study improves the diagnosis of liver cancer by using a novel parametric image combining various phases of dynamic CT imaging. The objective of this study is to investigate the diagnostic value of arterial to equilibrium enhancement washout (AEEW) obtained by image registration and dynamic subtraction in predicting tumor viability in a hepatocellular carcinoma (HCC) treated with transcatheter arterial chemoembolization (TACE). Forty patients who had forty-seven iodized-oil defect areas (IODAs) in HCCs treated with TACE were included. These patients were divided into two groups, one group with viable tumors (n = 27) and the other group with non-viable tumors (n = 20) in the IODAs. All the patients underwent triple-phase CT before and after TACE. The attenuation differences of the IODAs between the arterial and the equilibrium phases were measured and compared between two groups. Quantitative AEEW color maps of the whole liver were created from the triple-phase CT image by using prototype research software. Two radiologists independently analyzed following two sets of image: one with standard tri-phase CT images and the other with tri-phase CT images and quantitative AEEW color map images. The diagnostic performances in terms of mean sensitivity, specificity, and accuracy for identifying viable or non-viable tumors by using quantitative AEEW color map images in addition to tri-phase CT was larger than the performance obtained using tri-phase CT only. In conclusion, quantitative AEEW color map images improve the diagnostic performances of multiphasic CT for determining the viability of the IODA in a HCC treated with TACE.

  8. Optimization of the accuracy of retention and washout measurements of 99mTc-Sestamibi from breast tumours using an anthropomorphic phantom

    NASA Astrophysics Data System (ADS)

    Marshall, Christopher; Griffiths, Peter A.

    2005-05-01

    Quantifying the retention or washout of 99mTc-Sestamibi (MIBI) in breast tumours in vivo may provide a basis for predicting the chemotherapy response. The aim of this study is to investigate the variations and limitations of the different methods used to quantify these parameters. A phantom was developed that allowed the modelling of MIBI pharmacokinetics in both the breast tumour and normal breast tissue. Washout and retention were calculated from tumour uptake values based on (1) background corrected counts or (2) total counts in the tumour region of interest (ROI), or (3) tumour to background ratios (TBR), or (4) normalized TBR (nTBR). Method 1 was the most accurate method of quantification whilst method 3 was the most inaccurate. The accuracy of method 1 was independent of the times at which images were acquired, but three sources of error are identified involving incorrect background selection, ROI reproducibility and inconsistent temporal separation of images. In conclusion, background subtracted tumour counts should be used in the calculation of MIBI retention or washout. Accurate results are dependent on selecting the appropriate background, drawing consistent ROIs and using reproducible time intervals between images.

  9. Abilities of candesartan and other AT(1) receptor blockers to impair angiotensin II-induced AT(1) receptor activation after wash-out.

    PubMed

    Kiya, Yoshihiro; Miura, Shin-ichiro; Matsuo, Yoshino; Karnik, Sadashiva S; Saku, Keijiro

    2012-03-01

    Angiotensin II (Ang II) binds to Ang II type 1 (AT(1)) receptor and evokes cell signaling, and subsequently stimulates vasoconstriction and cell proliferation, which eventually lead to cardiovascular disease. Since most AT(1) receptor blockers (ARBs) have molecular (differential) effects, we evaluated the specific features of candesartan and compared the abilities of candesartan and other ARBs (olmesartan, telmisartan, valsartan, irbesartan and losartan) to bind to and activate AT(1) receptors using a cell-based wash-out assay. Each ARB blocked Ang II-induced extracellular signal-regulated kinase (ERK) activation and inositol phosphate production to different degrees after wash-out. In addition, a small difference in the molecular structure, i.e. a carboxyl group, between candesartan and candesartan-7H was associated with a difference in the degree of this blocking effect. In addition, interaction between Gln(257) in the AT(1) receptor and the carboxyl group of candesartan may be partially associated with the effect of candesartan after wash-out. Although our findings regarding the molecular effects of ARB are based on basic research, these findings may lead to an exciting new area in the clinical application of ARBs. PMID:21824992

  10. Effect of epidural saline washout on regression of sensory and motor block after epidural anaesthesia with 2% lidocaine and fentanyl in elderly patients.

    PubMed

    Park, E Y; Kil, H K; Park, W S; Lee, N-H; Hong, J-Y

    2009-03-01

    Seventy elderly males received lumbar epidural anaesthesia with 12 ml of 2% lidocaine containing fentanyl 50 mug. At the end of transurethral surgery, the washout group (n = 33) received an epidural bolus of 30 ml saline while the control group (n = 34) did not. Mean (SD) times to 1-grade (17.2 (11.9) vs 32.7 (11.3) min) and 2-grade regression (23.8 (12.2) vs 56.0 (23.9) min) of motor block, 3-dermatomal sensory regression (31.4 (11.6) vs 42.2 (14.4) min for cold and 30.8 (15.6) vs 40.6 (14.2) min for pinprick), and regression to S1 (57.7 (16.1) vs 76.2 (20.2) min for cold and 56.8 (17.3) vs 69.2 (16.2) min for pinprick) were significantly shorter in the washout group than the control group. There were no differences in postoperative pain scores and side effects between the two groups. We concluded that epidural washout facilitates regression of both motor and sensory block following epidural anaesthesia without reducing the postoperative analgesic benefit.

  11. Preventing a Washout.

    ERIC Educational Resources Information Center

    Poindexter, Dave

    1996-01-01

    Offers ideas for locating a roof leak. Discusses why many leaks originate in the roof's base flashings and the importance of knowing the roof's material makeup. Advocates keeping a roof-leak history and gives advice on performing inspections to check for leaks. Discusses how to find small holes in roofs. (RJM)

  12. Effects of dipyridamole and aminophylline on hemodynamics, regional myocardial blood flow and thallium-201 washout in the setting of a critical coronary stenosis

    SciTech Connect

    Granato, J.E.; Watson, D.D.; Belardinelli, L.; Cannon, J.M.; Beller, G.A. )

    1990-12-01

    Experiments were performed to characterize the interaction of intravenous dipyridamole and aminophylline on thallium-201 transport kinetics, regional myocardial blood flow and systemic hemodynamics in the presence of a critical coronary artery stenosis. In 12 dogs with a critical left anterior descending coronary artery stenosis, arterial pressure decreased from a mean value (+/- SEM) of 107 +/- 6 to 94 +/- 3 mm Hg and distal left anterior descending artery pressure decreased from 70 +/- 7 to 55 +/- 4 mm Hg after intravenous administration of dipyridamole. In the left anterior descending perfusion zone, the endocardial/epicardial flow ratio decreased from 0.70 to 0.36 and the intrinsic thallium washout rate was significantly prolonged. Intravenous aminophylline reversed the dipyridamole-induced systemic hypotension and transmural coronary steal and restored the thallium washout rate to baseline values. In six other dogs, aminophylline alone resulted in no alterations in systemic and coronary hemodynamics or regional myocardial blood flow. As expected, dipyridamole-induced vasodilation and coronary steal were prevented by aminophylline pretreatment. These data show that in a canine model of partial coronary stenosis, systemic hypotension, adverse regional flow effects and prolonged thallium-201 washout consequent to intravenously administered dipyridamole are promptly reversed by intravenous aminophylline administration. Aminophylline alone had no significant hemodynamic and coronary flow effects. This study provides further insight into the altered thallium kinetics occurring as a consequence of dipyridamole-induced vasodilation and suggests that the prompt reversal of symptoms and signs of ischemia with aminophylline in patients receiving intravenous dipyridamole for clinical imaging studies probably reflects the reversal of transmural coronary steal.

  13. Isotropic, anisotropic, and borehole washout analyses in Gulf of Mexico Gas Hydrate Joint Industry Project Leg II, Alaminos Canyon well 21-A

    USGS Publications Warehouse

    Lee, Myung W.

    2012-01-01

    Through the use of three-dimensional seismic amplitude mapping, several gas hydrate prospects were identified in the Alaminos Canyon area of the Gulf of Mexico. Two of the prospects were drilled as part of the Gulf of Mexico Gas Hydrate Joint Industry Program Leg II in May 2009, and a suite of logging-while-drilling logs was acquired at each well site. Logging-while-drilling logs at the Alaminos Canyon 21–A site indicate that resistivities of approximately 2 ohm-meter and P-wave velocities of approximately 1.9 kilometers per second were measured in a possible gas-hydrate-bearing target sand interval between 540 and 632 feet below the sea floor. These values are slightly elevated relative to those measured in the hydrate-free sediment surrounding the sands. The initial well log analysis is inconclusive in determining the presence of gas hydrate in the logged sand interval, mainly because large washouts in the target interval degraded well log measurements. To assess gas-hydrate saturations, a method of compensating for the effect of washouts on the resistivity and acoustic velocities is required. To meet this need, a method is presented that models the washed-out portion of the borehole as a vertical layer filled with seawater (drilling fluid). Owing to the anisotropic nature of this geometry, the apparent anisotropic resistivities and velocities caused by the vertical layer are used to correct measured log values. By incorporating the conventional marine seismic data into the well log analysis of the washout-corrected well logs, the gas-hydrate saturation at well site AC21–A was estimated to be in the range of 13 percent. Because gas hydrates in the vertical fractures were observed, anisotropic rock physics models were also applied to estimate gas-hydrate saturations.

  14. Bacterial Selection during the Formation of Early-Stage Aerobic Granules in Wastewater Treatment Systems Operated Under Wash-Out Dynamics

    PubMed Central

    Weissbrodt, David G.; Lochmatter, Samuel; Ebrahimi, Sirous; Rossi, Pierre; Maillard, Julien; Holliger, Christof

    2012-01-01

    Aerobic granular sludge is attractive for high-rate biological wastewater treatment. Biomass wash-out conditions stimulate the formation of aerobic granules. Deteriorated performances in biomass settling and nutrient removal during start-up have however often been reported. The effect of wash-out dynamics was investigated on bacterial selection, biomass settling behavior, and metabolic activities during the formation of early-stage granules from activated sludge of two wastewater treatment plants (WWTP) over start-up periods of maximum 60 days. Five bubble-column sequencing batch reactors were operated with feast-famine regimes consisting of rapid pulse or slow anaerobic feeding followed by aerobic starvation. Slow-settling fluffy granules were formed when an insufficient superficial air velocity (SAV; 1.8 cm s−1) was applied, when the inoculation sludge was taken from a WWTP removing organic matter only, or when reactors were operated at 30°C. Fast-settling dense granules were obtained with 4.0 cm s−1 SAV, or when the inoculation sludge was taken from a WWTP removing all nutrients biologically. However, only carbon was aerobically removed during start-up. Fluffy granules and dense granules were displaying distinct predominant phylotypes, namely filamentous Burkholderiales affiliates and Zoogloea relatives, respectively. The latter were predominant in dense granules independently from the feeding regime. A combination of insufficient solid retention time and of leakage of acetate into the aeration phase during intensive biomass wash-out was the cause for the proliferation of Zoogloea spp. in dense granules, and for the deterioration of BNR performances. It is however not certain that Zoogloea-like organisms are essential in granule formation. Optimal operation conditions should be elucidated for maintaining a balance between organisms with granulation propensity and nutrient removing organisms in order to form granules with BNR activities in short

  15. Quantification of regional fractional ventilation in human subjects by measurement of hyperpolarized 3He washout with 2D and 3D MRI.

    PubMed

    Horn, Felix C; Deppe, Martin H; Marshall, Helen; Parra-Robles, Juan; Wild, Jim M

    2014-01-15

    Multiple-breath washout hyperpolarized (3)He MRI was used to calculate regional parametric images of fractional ventilation (r) as the ratio of fresh gas entering a volume unit to the total end inspiratory volume of the unit. Using a single dose of inhaled hyperpolarized gas and a total acquisition time of under 1 min, gas washout was measured by dynamic acquisitions during successive breaths with a fixed delay. A two-dimensional (2D) imaging protocol was investigated in four healthy subjects in the supine position, and in a second protocol the capability of extending the washout imaging to a three-dimensional (3D) acquisition covering the whole lungs was tested. During both protocols, subjects were breathing comfortably, only restricted by synchronization of breathing to the sequence timings. The 3D protocol was also successfully tested on one patient with cystic fibrosis. Mean r values from each volunteer were compared with global gas volume turnover, as calculated from flow measurement at the mouth divided by total lung volume (from MRI images), and a significant correlation (r = 0.74, P < 0.05) was found. The effects of gravity on R were investigated, and an average decrease in r of 5.5%/cm (Δr = 0.016 ± 0.006 cm(-1)) from posterior to anterior was found in the right lung. Intersubject reproducibility of r imaging with the 2D and 3D protocol was tested, and a significant correlation between repeated experiments was found in a pixel-by-pixel comparison. The proposed methods can be used to measure r on a regional basis. PMID:24311749

  16. Bacterial Selection during the Formation of Early-Stage Aerobic Granules in Wastewater Treatment Systems Operated Under Wash-Out Dynamics.

    PubMed

    Weissbrodt, David G; Lochmatter, Samuel; Ebrahimi, Sirous; Rossi, Pierre; Maillard, Julien; Holliger, Christof

    2012-01-01

    Aerobic granular sludge is attractive for high-rate biological wastewater treatment. Biomass wash-out conditions stimulate the formation of aerobic granules. Deteriorated performances in biomass settling and nutrient removal during start-up have however often been reported. The effect of wash-out dynamics was investigated on bacterial selection, biomass settling behavior, and metabolic activities during the formation of early-stage granules from activated sludge of two wastewater treatment plants (WWTP) over start-up periods of maximum 60 days. Five bubble-column sequencing batch reactors were operated with feast-famine regimes consisting of rapid pulse or slow anaerobic feeding followed by aerobic starvation. Slow-settling fluffy granules were formed when an insufficient superficial air velocity (SAV; 1.8 cm s(-1)) was applied, when the inoculation sludge was taken from a WWTP removing organic matter only, or when reactors were operated at 30°C. Fast-settling dense granules were obtained with 4.0 cm s(-1) SAV, or when the inoculation sludge was taken from a WWTP removing all nutrients biologically. However, only carbon was aerobically removed during start-up. Fluffy granules and dense granules were displaying distinct predominant phylotypes, namely filamentous Burkholderiales affiliates and Zoogloea relatives, respectively. The latter were predominant in dense granules independently from the feeding regime. A combination of insufficient solid retention time and of leakage of acetate into the aeration phase during intensive biomass wash-out was the cause for the proliferation of Zoogloea spp. in dense granules, and for the deterioration of BNR performances. It is however not certain that Zoogloea-like organisms are essential in granule formation. Optimal operation conditions should be elucidated for maintaining a balance between organisms with granulation propensity and nutrient removing organisms in order to form granules with BNR activities in short

  17. Effect of cement washout on loosening of abutment screws and vice versa in screw- and cement- retained implant-supported dental prosthesis

    PubMed Central

    Kim, Seok-Gyu; Son, Mee-Kyoung

    2015-01-01

    PURPOSE The purpose of this study was to examine the abutment screw stability of screw- and cement-retained implant-supported dental prosthesis (SCP) after simulated cement washout as well as the stability of SCP cements after complete loosening of abutment screws. MATERIALS AND METHODS Thirty-six titanium CAD/CAM-made implant prostheses were fabricated on two implants placed in the resin models. Each prosthesis is a two-unit SCP: one screw-retained and the other cemented. After evaluating the passive fit of each prosthesis, all implant prostheses were randomly divided into 3 groups: screwed and cemented SCP (Control), screwed and noncemented SCP (Group 1), unscrewed and cemented SCP (Group 2). Each prosthesis in Control and Group 1 was screwed and/or cemented, and the preloading reverse torque value (RTV) was evaluated. SCP in Group 2 was screwed and cemented, and then unscrewed (RTV=0) after the cement was set. After cyclic loading was applied, the postloading RTV was measured. RTV loss and decementation ratios were calculated for statistical analysis. RESULTS There was no significant difference in RTV loss ratio between Control and Group 1 (P=.16). No decemented prosthesis was found among Control and Group 2. CONCLUSION Within the limits of this in vitro study, the stabilities of SCP abutment screws and cement were not significantly changed after simulated cement washout or screw loosening. PMID:26140172

  18. Accumulation and washout of 99mTc-sestamibi in osteoarthritic subchondral bone may indicate increased osteoclastic activity accompanying microfractures: a case study.

    PubMed

    Tanaka, Ryo; Ebine, Masato

    2016-01-01

    We show for the first time that imaging of osteoarthritic subchondral bone with 99mTc-sestamibi (MIBI) may be a valuable diagnostic tool to assess the severity of subchondral sclerosis. This is a report on a patient who had osteoarthritis of both knees and where MIBI was accumulated in the lesion sites. Due to the accumulation of MIBI in the bone, we believe that excessive stress had been applied to the bone and microfractures had activated bone remodeling. Typically, MIBI accumulation is not observed in the bone, but MIBI is believed to exhibit high accumulation where there is an increased presence of osteoblasts and osteoclasts. Osteoclasts absorb calcium, consequently causing a depolarization of the mitochondrial membrane potential, which may decrease the ability to retain MIBI and enhance washout. Pathological examination of the tissues of this case confirmed an abundance of osteoclasts. This suggests that using MIBI may be useful for determining the increased presence of osteoblasts and osteoclasts.

  19. The Kety-Schmidt Technique for Quantitative Perfusion and Oxygen Metabolism Measurements in the MR Environment

    PubMed Central

    Lee, John J.; Powers, William J.; Faulkner, Chad B.; Boyle, Patrick J.; Derdeyn, Colin P.

    2013-01-01

    The Kety-Schmidt technique provides quantitative measurement of whole brain cerebral blood flow (CBF). CBF is measured as the area between the arterial and venous washout curves of a diffusible tracer. Oxygen extraction and metabolism may be calculated from arterial and venous samples. In this report we present a method for performing these measurements in an MR environment. This technique could be useful for validation of MR methods of hemodynamic and metabolic measurements in humans. PMID:22997166

  20. Noninvasive identification of left main and triple vessel coronary artery disease: improved accuracy using quantitative analysis of regional myocardial stress distribution and washout of thallium-201

    SciTech Connect

    Maddahi, J.; Abdulla, A.; Garcia, E.V.; Swan, H.J.; Berman, D.S.

    1986-01-01

    The capabilities of visual and quantitative analysis of stress redistribution thallium-201 scintigrams, exercise electrocardiography and exercise blood pressure response were compared for correct identification of extensive coronary disease, defined as left main or triple vessel coronary artery disease, or both (50% or more luminal diameter coronary narrowing), in 105 consecutive patients with suspected coronary artery disease. Extensive disease was present in 56 patients and the remaining 49 had either less extensive coronary artery disease (n = 34) or normal coronary arteriograms (n = 15). Although exercise blood pressure response, exercise electrocardiography and visual thallium-201 analysis were highly specific (98, 88 and 96%, respectively), they were insensitive for identification of patients with extensive disease (14, 45 and 16%, respectively). Quantitative thallium-201 analysis significantly improved the sensitivity of visual thallium-201 analysis for identification of patients with extensive disease (from 16 to 63%, p less than 0.001) without a significant loss of specificity (96 versus 86%, p = NS). Eighteen (64%) of the 28 patients who were misclassified by visual analysis as having less extensive disease were correctly classified as having extensive disease by virtue of quantitative analysis of regional myocardial thallium-201 washout. When the results of quantitative thallium-201 analysis were combined with those of blood pressure and electrocardiographic response to exercise, the sensitivity and specificity for identification of patients with extensive disease was 86 and 76%, respectively, and the highest overall accuracy (0.82) was obtained.

  1. Occurrence of polybrominated diphenyl ethers in air and precipitation of the Pearl River Delta, South China: annual washout ratios and depositional rates.

    PubMed

    Zhang, Bao-Zhong; Guan, Yu-Feng; Li, Shao-Meng; Zeng, Eddy Y

    2009-12-15

    On the basis of a one-year (from October 2006 to September 2007) sampling campaign, 34 air samples and 23 bulk precipitation samples were collected in the Pearl River Delta (PRD) in southern China and analyzed for polybrominated diphenyl ethers (PBDEs). Fifteen tri- to deca-BDE congeners (sum of which is defined as Sigma15PBDE) were detected in more than 70% of the samples. In three urban-rural regions, Sigma15PBDE concentrations ranged from 77 to 372 pg/m3 in air (particulate + vapor) and 1.98 to 15.5 ng/L in rain (particle+dissolved) from Dongguan, from 195 to 1450 pg/m3 in air and 4.71 to 17.2 ng/L in rain from Shunde, and from 23.7 to 148 ng/L in rain from Guangzhou. Among the BDE congeners, BDE-209 was the predominant component. Linear correlations between the gas-particle partition coefficients (Kp) and the subcooled vapor pressures (P(O/L)) of individual BDE congeners were observed for both the wet and dry seasons, but the slopes (-0.572 to -0.525) of the fitted equations all substantially deviated from equilibrium condition (slope = -1). The total washout ratio by bulk rainfalls was determined to be 2 x 103 for tri-BDEs and 6 x 104 for BDE-209. The estimated annual dry and wet depositional rates were 6720 and 2460 kg/yr, respectively, for BDE-209, and 7270 and 2940 kg/yr for Sigma15PBDE in the PRD, indicating a dominant pathway for PBDEs input into the PRD soil and aquatic environments.

  2. Subcutaneous blood flow in psoriasis

    SciTech Connect

    Klemp, P.

    1985-03-01

    The simultaneously recorded disappearance rates of /sup 133/xe from subcutaneous adipose tissue in the crus were studied in 10 patients with psoriasis vulgaris using atraumatic labeling of the tissue in lesional skin (LS) areas and symmetrical, nonlesional skin (NLS) areas. Control experiments were performed bilaterally in 10 younger, healthy subjects. The subcutaneous washout rate constant was significantly higher in LS, 0.79 +/- 0.05 min-1 x 10(2) compared to the washout rate constant of NLS, 0.56 +/- 0.07 min-1. 10(2), or the washout rate constant in the normal subjects, 0.46 +/- 0.17 min-1 x 10(2). The mean washout rate constant in NLS was 25% higher than the mean washout rate constant in the normal subjects. The difference was, however, not statistically significant. Differences in the washout rate constants might be due to abnormal subcutaneous tissue-to-blood partition (lambda) in the LS--and therefore not reflecting the real differences in the subcutaneous blood flow (SBF). The lambda for /sup 133/Xe was therefore measured--using a double isotope washout method (/sup 133/Xe and (/sup 131/I)antipyrine)--in symmetrical sites of the lateral crus in LS and NLS of 10 patients with psoriasis vulgaris and in 10 legs of normal subjects. In LS the lambda was 4.52 +/- 1.67 ml/g, which was not statistically different from that of NLS, 5.25 +/- 2.19 ml/g, nor from that of normal subcutaneous tissue, 4.98 +/- 1.04 ml/g. Calculations of the SBF using the obtained lambda values gave a significantly higher SBF in LS, 3.57 +/- 0.23 ml/100 g/min, compared to SBF in the NLS, 2.94 +/- 0.37 ml/100 g/min. There was no statistically significant difference between SBF in NLS and SBF in the normal subjects. The increased SBF in LS of psoriatics might be a secondary phenomenon to an increased heat loss in the lesional skin.

  3. Cerebral Blood Flow Estimation Using Classification Techniques On A Sequence Of Low Resolution Tomographic Evolutive Images

    NASA Astrophysics Data System (ADS)

    Chan, Marie; Aguilar-Martin, Joseph; Boulanouar, Kader; Celsis, Pierre; Marc-Vergnes, Jean P.

    1989-05-01

    In order to improve the performance of the instrumental variable method (IVM) in calculating regional cerebral blood flow (rCBF) using Single Photon Emission Computed Tomography (SPELT), and inert diffusible tracer such as 133Xe, we use Learning Algorithms for Multivariate Data Analysis (LAMDA) to classify the voxels of the images of local concentrations in the brain. The LAMDA method correctly distinguished between extra and intra-cerebral voxels. However the topography of the intra-cerebral classes did not match the Regions Of Interest (ROI) defined on an anatomical basis. Provided that all the intra-cerebral classes contaminated by bone and air passage artefact were rejected, the results given by the NM are in good agreement with those derived by the bolus distribution principle. We thus conclude that LAMDA methods can improve the reliability of images of CBF estimates.

  4. Noninvasive method of estimating human newborn regional cerebral blood flow

    SciTech Connect

    Younkin, D.P.; Reivich, M.; Jaggi, J.; Obrist, W.; Delivoria-Papadopoulos, M.

    1982-12-01

    A noninvasive method of estimating regional cerebral blood flow (rCBF) in premature and full-term babies has been developed. Based on a modification of the /sup 133/Xe inhalation rCBF technique, this method uses eight extracranial NaI scintillation detectors and an i.v. bolus injection of /sup 133/Xe (approximately 0.5 mCi/kg). Arterial xenon concentration was estimated with an external chest detector. Cerebral blood flow was measured in 15 healthy, neurologically normal premature infants. Using Obrist's method of two-compartment analysis, normal values were calculated for flow in both compartments, relative weight and fractional flow in the first compartment (gray matter), initial slope of gray matter blood flow, mean cerebral blood flow, and initial slope index of mean cerebral blood flow. The application of this technique to newborns, its relative advantages, and its potential uses are discussed.

  5. Spatial anisotropy of xenon-defect configurations in cubic single crytals

    NASA Astrophysics Data System (ADS)

    Claes, J.; Namavar, F.; Rots, M.

    1982-03-01

    Ion-implanted tungsten and copper single crystals are investigated by the perturbed angular correlation technique, using an allowed β- γ cascade in 133Xe decay. The spatial distribution function describing the orientation of the quadrupole hyperfine interaction does not show up the cubic symmetry of the lattice in the case of xenon-induced radiation damage. This conclusion is interpreted in terms of xenon-vacancy loop interaction.

  6. Adrenergic vasoconstriction in peripheral nerves of the rabbit

    SciTech Connect

    Selander, D.; Mansson, L.G.; Karlsson, L.; Svanvik, J.

    1985-01-01

    The blood flow in the sciatic nerve of the rabbit was estimated from the wash out of intraneurally injected /sup 133/Xe. To avoid diffusion of the tracer into the surrounding muscular tissue, the nerve was covered by a gas-tight plastic film. Using this technique, the basal blood flow in the sciatic nerve was estimated to 35 ml X min-1 X 100 g-1. It was found that intraarterial norepinephrine and electrical stimulation of the lumbar sympathetic chain strongly reduced the wash out of /sup 133/Xe, which only can be explained by a pronounced reduction of the blood flow in the nerve itself. The blood flow again increased within 4 min of stopping the infusion of norepinephrine or the sympathetic stimulation. The prolonged effect and higher neurotoxicity of local anesthetics containing adrenaline may be explained by an alpha receptor-mediated vasoconstriction of the microvessels of peripheral nerves.

  7. Evidence for a local sympathetic venoarteriolar ''reflex'' in the dog hindleg

    SciTech Connect

    Henriksen, O.; Amtorp, O.; Faris, I.; Agerskov, K.

    1983-05-01

    The study was performed in order to determine whether a local sympathetic venoarteriolar ''reflex'' is present in the dog hindleg. Femoral artery blood flow was measured by an electromagnetic flowmeter probe, and blood flow in the thigh muscle and subcutaneous tissue distally in the paw was measured by the local 133Xe washout technique. Twenty experiments were carried out in seven dogs unilaterally sympathectomized 2-4 weeks previously. Resting vascular tone did not differ in the sympathectomized and nonsympathectomized legs. In the control leg, venous pressure elevation caused a decrease in femoral blood flow of 49% corresponding to an increase in vascular resistance of 58%. In muscle and subcutaneous tissue vascular resistance increased by 81% and 35%, respectively. In the denervated leg, venous stasis caused no change in total vascular resistance. In muscle the vascular resistance increased by only 24%. In subcutaneous tissue, vascular resistance decreased by 12%. The effect of acute lumbar sympathectomy was studied in another group of seven dogs. Operation caused an immediate decrease in vascular resistance of 40%. The increase in vascular resistance during venous stasis in the total leg, as well as in muscle and subcutaneous tissue, was not affected. However, acute lumbar sympathectomy combined with injection of phenoxybenzamine into the femoral artery almost abolished the vasoconstriction induced by venous stasis. In muscle, the increase in vascular resistance was still present, but considerably attenuated. In subcutaneous tissue, the normal response was completely blocked. Finally, local suction induced vasoconstriction in an adjoining area not subjected to changes in vascular transmural pressure, an effect that could be blocked by local neural blockade at the site of suction. The results strongly suggest that a local sympathetic veno-arteriolar (axon) ''reflex'' is present in muscle and subcutaneous tissue in the dog hindleg.

  8. Sympathetic reflex control of skeletal muscle blood flow in patients with congestive heart failure: evidence for beta-adrenergic circulatory control

    SciTech Connect

    Kassis, E.; Jacobsen, T.N.; Mogensen, F.; Amtorp, O.

    1986-11-01

    Mechanisms controlling forearm muscle vascular resistance (FMVR) during postural changes were investigated in seven patients with severe congestive heart failure (CHF) and in seven control subjects with unimpaired left ventricular function. Relative brachioradial muscle blood flow was determined by the local /sup 133/Xe-washout technique. Unloading of baroreceptors with use of 45 degree upright tilt was comparably obtained in the patients with CHF and control subjects. Control subjects had substantially increased FMVR and heart rate to maintain arterial pressure whereas patients with CHF had decreased FMVR by 51 +/- 11% and had no increase in heart rate despite a fall in arterial pressure during upright tilt. The autoregulatory and local vasoconstrictor reflex responsiveness during postural changes in forearm vascular pressures were intact in both groups. In the patients with CHF, the left axillary nerve plexus was blocked by local anesthesia. No alterations in forearm vascular pressures were observed. This blockade preserved the local regulation of FMVR but reversed the vasodilator response to upright tilt as FMVR increased by 30 +/- 7% (p less than .02). Blockade of central neural impulses to this limb combined with brachial arterial infusions of phentolamine completely abolished the humoral vasoconstriction in the tilted position. Infusions of propranolol to the contralateral brachial artery that did not affect baseline values of heart rate, arterial pressure, or the local reflex regulation of FMVR reversed the abnormal vasodilator response to upright tilt as FMVR increased by 42 +/- 12% (p less than .02). Despite augmented baseline values, forearm venous but not arterial plasma levels of epinephrine increased in the tilted position, as did arteri rather than venous plasma concentrations of norepinephrine in these patients.

  9. Regulation of local subcutaneous blood flow in patients with psoriasis and effects of antipsoriatic treatment on subcutaneous blood flow

    SciTech Connect

    Klemp, P.

    1985-08-01

    Local regulation of the doubled subcutaneous blood flow (SBF) rates in psoriatic lesional skin was studied in 8 patients using a traumatic epicutaneous /sup 133/Xe labeling washout technique. Venous stasis of 40 mm Hg induced a significant reduction in the SBF (-34%, p less than 0.01), i.e., a normal vasoconstrictor response. Limb elevation of 40 cm above heart level induced no statistical changes in the SBF (p = 0.50), i.e., a normal local autoregulation response. This indicates normal, local regulation mechanisms of SBF in psoriasis. In another 8 patients, the effect on SBF of a 4-week antipsoriatic treatment with tar was studied in lesional and symmetrically nonlesional skin areas. One patient was clear of psoriasis on day 22, and was followed only to that time. The mean pretreatment SBF in lesional skin areas was 3.87 +/- SD 0.78 ml X (100 g X min)-1, which was not statistically different from measurements on days 3, 7, 14, and 21 after treatment had started. Between day 21 and day 28, the SBF decreased significantly to 3.38 +/- SD 0.78 ml X (100 g X min)-1, p less than 0.05. The difference between the pretreatment SBF and SBF at the end of treatment was statistically significant, p less than 0.05. The changes in SBF in symmetrically nonlesional skin areas were statistically nonsignificant during the period of treatment. Pretreatment SBF was 2.60 +/- SD 1.08 (N = 8), and on day 28 was 1.91 +/- SD 0.74 ml X (100 g X min)-1 (N = 7). However, the tendency of a decreasing SBF at the end of treatment was a clear trend, since SBF in 6 of 7 patients decreased during the third week and in the patient who was discharged on day 22, a decrease in the SBF was observed on days 14 and 21.

  10. Silicones used in permanent and semi-permanent hair dyes to reduce the fading and color change process of dyed hair occurred by wash-out or UV radiation.

    PubMed

    Schlosser, Arndt

    2004-01-01

    Different kinds of silicones were incorporated directly into permanent and semi-permanent hair dyes. To ensure that the silicone was deposited to the hair fibers Si deposition was measured. Hair treated with a silicone free control or the silicone modified hair dyes was tested for color and lightness change (fading) by washing the treated tresses several times and measuring the color change. In a second experiment, hair treated with permanent hair dye was treated with UV radiation to show if silicones can reduce the color change initiated by UV light. The influence of the silicones to dry combing forces of permanent dyed hair untreated and treated with UV was also investigated. The tests showed that dimethiconol/dimethicone mixtures can reduce the washout of hair colorant clearly and silicone resins like trimethylsiloxysilcate or propylphenylsilsesquioxane are able to decrease the color change occurred by UV radiation in dyed hair.

  11. Explosive washout lagoons soils operable unit supplemental investigation technical and environmental management support of installation restoration technology development program, Umatilla Depot Activity, Hermiston. Oregon. Phase 2. Final Draft report, May 1991-May 1992

    SciTech Connect

    Raymondi, R.

    1992-04-15

    As part of an ongoing Remedial Investigation/Feasibility Study at the Umatilla Army Depot, the soils of the Explosives Washout Lagoons at that installation were assigned as an operable unit for a possible expedited remedial action. Additional sampling was conducted to determine the explosives concentrations at depth beneath the lagoons, and to verify the absence of other contaminants. Explosives contamination was found from the ground surface to the groundwater at 47 feet. Concentrations were much higher in the top 3 feet than in the soil beneath that. Other organic contamination was not present; some metals were elevated slightly above background. The results of the study are being used in a feasibility study of remedial action alternatives.

  12. Explosives Washout Lagoons Soils Operable Unit supplemental investigation technical and environmental management support of installation-restoration technology development program, Umatilla Depot Activity, Hermiston, Oregon. Final report, May 91-May 92

    SciTech Connect

    Raymondi, R.

    1992-04-15

    As part of an ongoing Remedial Investigation/Feasibility Study at the Umatilla Army Depot, the soils of the Explosives Washout Lagoons at that installation were assigned as an operable unit for a possible expedited remedial action. Additional sampling was conducted to determine the explosives concentrations at depth beneath the lagoons, and to verify the absence of other contaminants. Explosives contamination was found from the ground surface to the groundwater at 47 feet. Concentrations were much higher in the top 3 feet than in the soil beneath that. Other organic contamination was not present; some metals were elevated slightly above background. The results of the study are being used in a feasibility study of remedial action alternatives.

  13. Correlation of clinical and angiographic findings in brain ischemia with regional cerebral blood flow measured by the xenon inhalation technique

    SciTech Connect

    Awad, I.; Little, J.R.; Furlan, A.J.; Weinstein, M.

    1982-07-01

    Eighty-eight patients with brain ischemia underwent cerebral angiography and measurement of regional cerebral blood flow (rCBF) after /sup 133/Xe inhalation. A fast compartment flow rate and an initial slope index were computed for each detector and for each hemisphere. The clinical presentation, angiographic findings, and rCBF results were then examined for significant correlations. Patients with hemispheric infarction most frequently showed bilateral diffusely decreased rCBF. In patients with transient ischemic attacks, no specific pattern emerged. Patients with unilateral internal carotid artery occlusion frequently hd bilateral diffusely decreased rCBF. Patients with severe internal carotid artery stenosis were more likely to show decreased rCBF than were patients with mild or moderate stenosis. The initial slope index seemed to be a more sensitive indicator of brain ischemia than the fast compartment flow rate. The possible pathophysiological significance and relationship to patient management of the various rCBF patterns are discussed.

  14. Dismantling techniques

    SciTech Connect

    Wiese, E.

    1998-03-13

    Most of the dismantling techniques used in a Decontamination and Dismantlement (D and D) project are taken from conventional demolition practices. Some modifications to the techniques are made to limit exposure to the workers or to lessen the spread of contamination to the work area. When working on a D and D project, it is best to keep the dismantling techniques and tools as simple as possible. The workers will be more efficient and safer using techniques that are familiar to them. Prior experience with the technique or use of mock-ups is the best way to keep workers safe and to keep the project on schedule.

  15. Xenon-133 determination of muscle blood flow: Use in evaluating cardioactive drugs

    SciTech Connect

    Wexler, J.P.; Davis, L.; Mancini, D.; Chadwick, B.; Le Jemtel, T.

    1985-05-01

    Cardioactive drugs may effect both the central and peripheral circulatory systems. The effects on the central and peripheral circulatory systems of chronic Captorpril therapy in 7 pts with severe congestive heart failure (CHF) were evaluated simultaneously. Skeletal muscle blood flow (SMBF) determined using 133-Xe washout and a Cd/Te detector, oxygen consumption (VO/sub 2/), and radial artery and femoral vein O/sub 2/ concentration difference (A-V) were determined at rest and peak upright bicycle exercise before (BT) and after (AT) 6-12 weeks of Captopril therapy. In CI pts there was a significant increase in VO/sub 2/ and SMBF AT vs BT. In contrast, in CNC pts there was no change in VO/sub 2/ and a significant decrease in SMBF AT vs BT. In pts with severe CHF who are CI, there is an apparent fall in peripheral vascular resistance (PVR). In contrast, in CNC pts there is an increase in PVR. This study demonstrates that SMBF determines using 133-Xe is an important method for determining the effects of cardioactive drugs.

  16. Decomposition techniques

    USGS Publications Warehouse

    Chao, T.T.; Sanzolone, R.F.

    1992-01-01

    Sample decomposition is a fundamental and integral step in the procedure of geochemical analysis. It is often the limiting factor to sample throughput, especially with the recent application of the fast and modern multi-element measurement instrumentation. The complexity of geological materials makes it necessary to choose the sample decomposition technique that is compatible with the specific objective of the analysis. When selecting a decomposition technique, consideration should be given to the chemical and mineralogical characteristics of the sample, elements to be determined, precision and accuracy requirements, sample throughput, technical capability of personnel, and time constraints. This paper addresses these concerns and discusses the attributes and limitations of many techniques of sample decomposition along with examples of their application to geochemical analysis. The chemical properties of reagents as to their function as decomposition agents are also reviewed. The section on acid dissolution techniques addresses the various inorganic acids that are used individually or in combination in both open and closed systems. Fluxes used in sample fusion are discussed. The promising microwave-oven technology and the emerging field of automation are also examined. A section on applications highlights the use of decomposition techniques for the determination of Au, platinum group elements (PGEs), Hg, U, hydride-forming elements, rare earth elements (REEs), and multi-elements in geological materials. Partial dissolution techniques used for geochemical exploration which have been treated in detail elsewhere are not discussed here; nor are fire-assaying for noble metals and decomposition techniques for X-ray fluorescence or nuclear methods be discussed. ?? 1992.

  17. Miscellaneous Techniques

    NASA Astrophysics Data System (ADS)

    Jha, Shyam N.

    Nondestructive way of determining the food quality is the need of the hour. Till now major methods such as colour measurements and their modeling; machine vision systems; X-ray, CT and MRI; NIR spectroscopy; electronic nose and tongue; and ultrasonic technology have been discussed in detail. These techniques, in general, are considered to be sophisticated and costly, and therefore probably are not being adopted as fast as it should be. I am however of the reverse opinion. While going through these techniques, it has been seen that majority of quality parameters have been measured and correlated with the signals obtained using different equipment.

  18. Anisotropic models to account for large borehole washouts to estimate gas hydrate saturations in the Gulf of Mexico Gas Hydrate Joint Industry Project Leg II Alaminos 21 B well

    USGS Publications Warehouse

    Lee, M.W.; Collett, T.S.; Lewis, K.A.

    2012-01-01

    Through the use of 3-D seismic amplitude mapping, several gashydrate prospects were identified in the Alaminos Canyon (AC) area of the Gulf of Mexico. Two locations were drilled as part of the Gulf of MexicoGasHydrate Joint Industry Project Leg II (JIP Leg II) in May of 2009 and a comprehensive set of logging-while-drilling (LWD) logs were acquired at each well site. LWD logs indicated that resistivity in the range of ~2 ohm-m and P-wave velocity in the range of ~1.9 km/s were measured in the target sand interval between 515 and 645 feet below sea floor. These values were slightly elevated relative to those measured in the sediment above and below the target sand. However, the initial well log analysis was inconclusive regarding the presence of gashydrate in the logged sand interval, mainly because largewashouts caused by drilling in the target interval degraded confidence in the well log measurements. To assess gashydratesaturations in the sedimentary section drilled in the Alaminos Canyon 21B (AC21-B) well, a method of compensating for the effect of washouts on the resistivity and acoustic velocities was developed. The proposed method models the washed-out portion of the borehole as a vertical layer filled with sea water (drilling fluid) and the apparent anisotropic resistivity and velocities caused by a vertical layer are used to correct the measured log values. By incorporating the conventional marine seismic data into the well log analysis, the average gashydratesaturation in the target sand section in the AC21-Bwell can be constrained to the range of 8–28%, with 20% being our best estimate.

  19. Electrochemical Techniques

    SciTech Connect

    Chen, Gang; Lin, Yuehe

    2008-07-20

    Sensitive and selective detection techniques are of crucial importance for capillary electrophoresis (CE), microfluidic chips, and other microfluidic systems. Electrochemical detectors have attracted considerable interest for microfluidic systems with features that include high sensitivity, inherent miniaturization of both the detection and control instrumentation, low cost and power demands, and high compatibility with microfabrication technology. The commonly used electrochemical detectors can be classified into three general modes: conductimetry, potentiometry, and amperometry.

  20. Diet-induced changes in subcutaneous adipose tissue blood flow in man: effect of beta-adrenoceptor inhibition.

    PubMed

    Simonsen, L; Bülow, J; Astrup, A; Madsen, J; Christensen, N J

    1990-06-01

    The effect of a carbohydrate-rich meal on subcutaneous adipose tissue blood flow was studied with and without continuous i.v. infusion of propranolol in healthy volunteers. The subcutaneous adipose tissue blood flow was measured with the 133Xe washout method in three different locations: the forearm, the thigh and the abdomen. The subjects were given a meal consisting of white bread, jam, honey and apple juice (about 2300 kJ). The meal induced a twofold increase in blood flow in the examined tissues. Propranolol abolished the flow increase in the thigh and the abdomen and reduced it in the forearm. This indicates that the mechanism for the flow increase is elicited by a stimulation of vascular beta-adrenoceptors in the subcutaneous adipose tissue, since the beta-adrenoceptor inhibition did not affect the overall metabolic and hormonal responses to the meal.

  1. Subcutaneous blood flow in early male pattern baldness

    SciTech Connect

    Klemp, P.; Peters, K.; Hansted, B.

    1989-05-01

    The subcutaneous blood flow (SBF) was measured by the /sup 133/Xe washout method in the scalp of 14 patients with early male pattern baldness. Control experiments were performed in 14 normal haired men matched for age. The SBF in the scalp of the normal individuals was about 10 times higher than previously reported SBF values in other anatomical regions. In patients with early male pattern baldness, SBF was 2.6 times lower than the values found in the normal individuals (13.7 +/- 9.6 vs 35.7 +/- 10.5 ml/100 g/min-1). This difference was statistically significant (p much less than 0.001). A reduced nutritive blood flow to the hair follicles might be a significant event in the pathogenesis of early male pattern baldness.

  2. SPECT study of regional cerebral blood flow in Alzheimer disease

    SciTech Connect

    Bonte, F.J.; Ross, E.D.; Chehabi, H.H.; Devous, M.D. Sr.

    1986-07-01

    A common cause of dementia in late midlife and old age is Alzheimer disease (AD), which affects more than one in 20 individuals over the age of 65. Past studies of regional cerebral blood flow (rCBF) in patients with AD here suggested blood flow abnormalities, but findings have differed. We have studied 37 patients diagnosed as having AD with inhalation and washout of /sup 133/Xe and single-photon emission computed tomography (SPECT), obtaining evidence of abnormal rCBF patterns in 19. Flow reductions were most common in the temporoparietal regions and were occasionally found in the frontal areas. Investigators using positron-emission tomography (PET) have identified similar findings with respect to rCBF and regional oxygen, glucose, and protein metabolism. The SPECT determination of rCBF, which gives information similar to that provided by PET, may assume importance in the diagnosis of AD and in the differential diagnosis of the dementias.

  3. Local variation in cutaneous and subcutaneous blood flow measured by CdTe(C1) minidetectors in normal and psoriatic skin

    SciTech Connect

    Klemp, P.; Bojsen, J.

    1986-02-01

    The accuracy of the /sup 133/Xe washout method and the validity of newly developed cadmium telluride CdTe(Cl) minisemiconductor detectors were estimated by performing comparative, simultaneous measurements of both cutaneous (CBF) and subcutaneous (SBF) blood flow using 2 conventional scintillation sodium iodide NaI(Tl) and CdTe(Cl) detectors over the same radioactive depot in each of 10 individuals. The accuracy of the /sup 133/Xe washout method was found to be 13-15% (C.V.) for the CBF measurements and 9-12% (C.V.) for the SBF measurements. The CdTe(Cl) detectors, which have a weight of 20 g and were attached directly over the radioactive depot, may replace stationary NaI(Tl) detectors placed 20 cm from the depot for measurements of both CBF and SBF. Two CdTe(Cl) detectors were used for estimations of the local variation in CBF and SBF within a distance of 5 cm in normal skin of 10 individuals. The C.V. was 7% for the CBF measurements and 18% for the SBF measurements. Measurements of CBF and SBF were performed in 6 psoriatic patients who developed typical Woronoff rings. The local CBF differed significantly from the center of psoriatic plaques to the margin, in the Woronoff ring, and in nonlesional skin. In contrast, SBF was remarkably equal within the plaque and in the Woronoff ring. Cutaneous blood flow in chronic stable, lesional psoriatic skin was significantly lower than previously published values for active lesional psoriatic skin, but significantly higher than CBF in normal individuals. Measurements of CBF in tetrahydrofurfuryl nicotinic acid (Trafuril)-treated skin showed higher values than measurements of CBF in the postischemic hyperemia period both in normal and in lesional psoriatic skin. Trafuril induced a significant increase of CBF in both lesional and nonlesional skin.

  4. Suppression of VEGF-induced angiogenesis by the protein tyrosine kinase inhibitor, lavendustin A.

    PubMed Central

    Hu, D E; Fan, T P

    1995-01-01

    1. Vascular endothelial growth factor (VEGF) is a heparin-binding angiogenic factor which specifically acts on endothelial cells via distinct membrane-spanning tyrosine kinase receptors. Here we used the rat sponge implant model to test the hypothesis that the angiogenic activity of VEGF can be suppressed by protein tyrosine kinase (PTK) inhibitors. 2. Neovascular responses in subcutaneous sponge implants were determined by measurements of relative sponge blood flow by use of a 133Xe clearance technique, and confirmed by histological studies and morphometric analysis. 3. Daily local administration of 250 ng VEGF165 accelerated the rate of 133Xe clearance from the sponges and induced an intense neovascularisation. This VEGF165-induced angiogenesis was inhibited by daily co-administration of the selective PTK inhibitor, lavendustin A (10 micrograms), but not its negative control, lavendustin B (10 micrograms). Blood flow measurements and morphometric analysis of 8-day-old sponges showed that lavendustin A reduced the 133Xe clearance of VEGF165-treated sponges from 32.9 +/- 1.5% to 20.9 +/- 1.6% and the total fibrovascular growth area from 62.4 +/- 6.1% to 21.6 +/- 6.8% (n = 12, P < 0.05). 4. Co-injection of suramin (3 mg), an inhibitor of heparin-binding growth factors, also suppressed the VEGF165-elicited neovascular response. In contrast, neither lavendustin A nor suramin produced any effect on the basal sponge-induced angiogenesis. 5. When given alone, low doses of VEGF165 (25 ng) or basic fibroblast growth factor (bFGF; 10 ng) did not modify the basal sponge-induced neovascularisation.(ABSTRACT TRUNCATED AT 250 WORDS) Images Figure 2 Figure 2 PMID:7533611

  5. Cerebral blood flow in the newborn infant: comparison of Doppler ultrasound and /sup 133/xenon clearance

    SciTech Connect

    Greisen, G.; Johansen, K.; Ellison, P.H.; Fredriksen, P.S.; Mali, J.; Friis-Hansen, B.

    1984-03-01

    Two techniques of Doppler ultrasound examination, continuous-wave and range-gated, applied to the anterior cerebral artery and to the internal carotid artery, were compared with /sup 133/xenon clearance after intravenous injection. Thirty-two sets of measurements were obtained in 16 newborn infants. The pulsatility index, the mean flow velocity, and the end-diastolic flow velocity were read from the Doppler recordings. Mean cerebral blood flow was estimated from the /sup 133/Xe clearance curves. The correlation coefficients between the Doppler and the /sup 133/Xe measurements ranged from 0.41 to 0.82. In the subset of 16 first measurements in each infant, there were no statistically significant differences between the correlation coefficients of the various Doppler ultrasound variables, but the correlation coefficients were consistently lower for the pulsatility index than for mean flow velocity or end-diastolic flow velocity, and they were consistently higher for the range-gated than for the continuous-wave Doppler technique.

  6. The radiocarbon hydroxyl technique

    NASA Technical Reports Server (NTRS)

    Campbell, Malcolm J.; Sheppard, John C.

    1994-01-01

    The Radiocarbon Technique depends upon measuring the rate of oxidation of CO in an essentially unperturbed sample of air. The airborne technique is slightly different. Hydroxyl concentrations can be calculated directly; peroxyl concentrations can be obtained by NO doping.

  7. Nondestructive evaluation technique guide

    NASA Technical Reports Server (NTRS)

    Vary, A.

    1973-01-01

    A total of 70 individual nondestructive evaluation (NDE) techniques are described. Information is presented that permits ease of comparison of the merits and limitations of each technique with respect to various NDE problems. An NDE technique classification system is presented. It is based on the system that was adopted by the National Materials Advisory Board (NMAB). The classification system presented follows the NMAB system closely with the exception of additional categories that have been added to cover more advanced techniques presently in use. The rationale of the technique is explained. The format provides for a concise description of each technique, the physical principles involved, objectives of interrogation, example applications, limitations of each technique, a schematic illustration, and key reference material. Cross-index tabulations are also provided so that particular NDE problems can be referred to appropriate techniques.

  8. Seals and Sealing Techniques

    NASA Technical Reports Server (NTRS)

    1972-01-01

    Developments by the aerospace industry in seals and sealing techniques are announced for possible use in other areas. The announcements presented are grouped as: sealing techniques for cryogenic fluids, high pressure applications, and modification for improved performance.

  9. Cutaneous blood flow in psoriasis

    SciTech Connect

    Klemp, P.; Staberg, B.

    1983-12-01

    The disappearance rate of /sup 133/Xe was studied in 20 patients with psoriasis vulgaris, using an epicutaneous labeling technique in involved skin lesions or normal-appearing skin of the proximal extensor site of the forearm. Control experiments were performed in 10 normal subjects. Calculations of the cutaneous blood flow (CBF) in psoriatic skin lesions were performed using a tissue-to-blood partition coefficient for /sup 133/Xe, lambda c,pso, of 1.2 ml/100 g/min. lambda c,pso was estimated after the relative content of water, lipids, and proteins had been analyzed in psoriatic skin biopsies of 6 patients with untreated psoriasis. The mean relative content of water was markedly reduced to 23.5 +/- 1.5% (SEM), and lipids and proteins were markedly increased to 2.5 +/- 0.7% and 74.0 +/- 2.2, respectively, compared to previously published data for normal skin (water 72.5%, lipids 1%, proteins 26.5%). Mean CBF in untreated psoriatic skin was 63.5 +/- 9.0 ml/100 g/min. This was significantly higher than the mean CBF in 10 normal subjects, 6.3 +/- 0.5 ml/100 g/min (p much less than 0.0001). Mean CBF in normal-appearing skin in patients with psoriasis was 11.0 +/- 1.3 ml/100 g/min. This was significantly higher than CBF in normal subjects (p less than 0.0002).

  10. [Main relaxation techniques].

    PubMed

    Mateos Rodilla, Juana

    2002-11-01

    After having provided a detailed explanation on what relaxation consists of (see Rev. Rol Enf 2002; 25(9):582-586), the author presents a recap of the major known relaxation techniques including progressive muscular therapy, yoga stretching exercises, breathing techniques, therapeutic massages, meditation,... emphasizing the theoretical basis and practical experience as a function of each technique; each person ought to adopt those techniques which are most appropriate.

  11. Drilling technique for crystals

    NASA Technical Reports Server (NTRS)

    Hunter, T.; Miyagawa, I.

    1977-01-01

    Hole-drilling technique uses special crystal driller in which drill bit rotates at fixed position at speed of 30 rpm while crystal slowly advances toward drill. Technique has been successfully applied to crystal of Rochell salt, Triglycine sulfate, and N-acetyglycine. Technique limits heat buildup and reduces strain on crystal.

  12. Quality Attribute Techniques Framework

    NASA Astrophysics Data System (ADS)

    Chiam, Yin Kia; Zhu, Liming; Staples, Mark

    The quality of software is achieved during its development. Development teams use various techniques to investigate, evaluate and control potential quality problems in their systems. These “Quality Attribute Techniques” target specific product qualities such as safety or security. This paper proposes a framework to capture important characteristics of these techniques. The framework is intended to support process tailoring, by facilitating the selection of techniques for inclusion into process models that target specific product qualities. We use risk management as a theory to accommodate techniques for many product qualities and lifecycle phases. Safety techniques have motivated the framework, and safety and performance techniques have been used to evaluate the framework. The evaluation demonstrates the ability of quality risk management to cover the development lifecycle and to accommodate two different product qualities. We identify advantages and limitations of the framework, and discuss future research on the framework.

  13. The immediate effect of individual manipulation techniques on pulmonary function measures in persons with chronic obstructive pulmonary disease

    PubMed Central

    Noll, Donald R; Johnson, Jane C; Baer, Robert W; Snider, Eric J

    2009-01-01

    Background The use of manipulation has long been advocated in the treatment of chronic obstructive pulmonary disease (COPD), but few randomized controlled clinical trials have measured the effect of manipulation on pulmonary function. In addition, the effects of individual manipulative techniques on the pulmonary system are poorly understood. Therefore, the purpose of this study was to determine the immediate effects of four osteopathic techniques on pulmonary function measures in persons with COPD relative to a minimal-touch control protocol. Methods Persons with COPD aged 50 and over were recruited for the study. Subjects received five, single-technique treatment sessions: minimal-touch control, thoracic lymphatic pump (TLP) with activation, TLP without activation, rib raising, and myofascial release. There was a 4-week washout period between sessions. Protocols were given in random order until all five techniques had been administered. Pulmonary function measures were obtained at baseline and 30-minutes posttreatment. For the actual pulmonary function measures and percent predicted values, Wilcoxon signed rank tests were used to test within-technique changes from baseline. For the percent change from baseline, Friedman tests were used to test for between-technique differences. Results Twenty-five subjects were enrolled in the study. All four tested osteopathic techniques were associated with adverse posttreatment changes in pulmonary function measures; however, different techniques changed different measures. TLP with activation increased posttreatment residual volume compared to baseline, while TLP without activation did not. Side effects were mild, mostly posttreatment chest wall soreness. Surprisingly, the majority of subjects believed they could breathe better after receiving osteopathic manipulation. Conclusion In persons with COPD, TLP with activation, TLP without activation, rib raising, and myofascial release mildly worsened pulmonary function measures

  14. [Research Progress of Application of Microfluidics Techniques in Cryopreservation].

    PubMed

    Zhou, Nanfeng; Yang, Yun; Zhou, Xinli

    2015-06-01

    Microfluidics technology may be an effective method to solve some problems in cryopreservation. This review presents the research progress of microfluidics technology in the field of cell membrane transport properties, cryoprotectant addition and washout and the vitrification for cryopreservation of biological materials. Existing problems of microfluidics technology in the application of cryopreservation are summarized and future research directions are indicated as well.

  15. Emerging optical nanoscopy techniques

    PubMed Central

    Montgomery, Paul C; Leong-Hoi, Audrey

    2015-01-01

    To face the challenges of modern health care, new imaging techniques with subcellular resolution or detection over wide fields are required. Far field optical nanoscopy presents many new solutions, providing high resolution or detection at high speed. We present a new classification scheme to help appreciate the growing number of optical nanoscopy techniques. We underline an important distinction between superresolution techniques that provide improved resolving power and nanodetection techniques for characterizing unresolved nanostructures. Some of the emerging techniques within these two categories are highlighted with applications in biophysics and medicine. Recent techniques employing wider angle imaging by digital holography and scattering lens microscopy allow superresolution to be achieved for subcellular and even in vivo, imaging without labeling. Nanodetection techniques are divided into four subcategories using contrast, phase, deconvolution, and nanomarkers. Contrast enhancement is illustrated by means of a polarized light-based technique and with strobed phase-contrast microscopy to reveal nanostructures. Very high sensitivity phase measurement using interference microscopy is shown to provide nanometric surface roughness measurement or to reveal internal nanometric structures. Finally, the use of nanomarkers is illustrated with stochastic fluorescence microscopy for mapping intracellular structures. We also present some of the future perspectives of optical nanoscopy. PMID:26491270

  16. Techniques for Teachers Section

    ERIC Educational Resources Information Center

    Tait, A., Ed.

    1973-01-01

    Includes a simple technique to demonstrate Millikan's oil drop experiment, an environmental studies experiment to measure dissolved oxygen in water samples, and a technique to demonstrate action-reaction. Science materials described are the Pol-A-Star Tomiscope, Nuffield chemistry film loops, air pucks and pH meters. (JR)

  17. Contamination Control Techniques

    SciTech Connect

    EBY, J.L.

    2000-05-16

    Welcome to a workshop on contamination Control techniques. This work shop is designed for about two hours. Attendee participation is encouraged during the workshop. We will address different topics within contamination control techniques; present processes, products and equipment used here at Hanford and then open the floor to you, the attendees for your input on the topics.

  18. Techniques for Learning Vocabulary.

    ERIC Educational Resources Information Center

    Weatherford, H. Jarold

    A variety of classroom techniques for second language vocabulary learning are described, based on the principle that different approaches work with different students under varying conditions. The techniques include: rote rehearsal; the use of visual aids, including items that are acted out by students for the benefit of the class; role-playing;…

  19. Nonchemical decontamination techniques

    SciTech Connect

    Allen, R.P.

    1985-06-01

    The decontamination techniques summarized in this article represent a variety of surface cleaning methods developed or adapted for component and facility-type decontamination applications ranging from small hand tools to reactor cavities and other large surface areas. Representative nonchemical decontamination techniques include: ultrasonics, abrasive cleaning, high-pressure Freon cleaning, and vibratory finishing.

  20. Political Campaign Techniques.

    ERIC Educational Resources Information Center

    Institute for Political/Legal Education, Sewell, NJ.

    Techniques, materials, and coordinating efforts used in a political campaign are outlined for high school students. The objective is to familiarize students with these techniques so that they can become effective campaign volunteers. Topics include the candidate and the press, campaign publicity materials, organization of headquarters, receptions,…

  1. Emerging Imaging Techniques

    PubMed Central

    McVeigh, Elliot R.

    2007-01-01

    This article reviews recent developments in selected imaging technologies focused on the cardiovascular system. The techniques covered are: ultrasound biomicroscopy (UBM), microSPECT, microPET, near infrared imaging, and quantum dots. For each technique, the basic physical principles are explained and recent example applications demonstrated. PMID:16614313

  2. Analog signal isolation techniques

    SciTech Connect

    Beadle, E.R.

    1992-12-31

    This paper discusses several techniques for isolating analog signals in an accelerator environment. The techniques presented here encompass isolation amplifiers, voltage-to-frequency converters (VIFCs), transformers, optocouplers, discrete fiber optics, and commercial fiber optic links. Included within the presentation of each method are the design issues that must be considered when selecting the isolation method for a specific application.

  3. Analog signal isolation techniques

    SciTech Connect

    Beadle, E.R.

    1992-01-01

    This paper discusses several techniques for isolating analog signals in an accelerator environment. The techniques presented here encompass isolation amplifiers, voltage-to-frequency converters (VIFCs), transformers, optocouplers, discrete fiber optics, and commercial fiber optic links. Included within the presentation of each method are the design issues that must be considered when selecting the isolation method for a specific application.

  4. Simulation verification techniques study

    NASA Technical Reports Server (NTRS)

    Schoonmaker, P. B.; Wenglinski, T. H.

    1975-01-01

    Results are summarized of the simulation verification techniques study which consisted of two tasks: to develop techniques for simulator hardware checkout and to develop techniques for simulation performance verification (validation). The hardware verification task involved definition of simulation hardware (hardware units and integrated simulator configurations), survey of current hardware self-test techniques, and definition of hardware and software techniques for checkout of simulator subsystems. The performance verification task included definition of simulation performance parameters (and critical performance parameters), definition of methods for establishing standards of performance (sources of reference data or validation), and definition of methods for validating performance. Both major tasks included definition of verification software and assessment of verification data base impact. An annotated bibliography of all documents generated during this study is provided.

  5. Laser remote sensing techniques

    NASA Technical Reports Server (NTRS)

    Grant, William B.

    1987-01-01

    The properties and advantages of remote sensing lasers are discussed. The theory of nonresonant techniques, which is based on the lidar equation and elastic backscatter, and their applications to aerosol and meteorological parameters are examined. The characteristics and applications of the differential absorption lidar technique, the fluorescence technique, and Raman scattering are described. The use of a laser heterodyne radiometer and fiber optics for remote sensing is studied. Future developments in the field of remote sensing, in particular the improvement of laser sources, the fabrication of compact remote sensing instruments, and space-borne applications for lidar, are considered.

  6. Island custom blocking technique

    SciTech Connect

    Carabetta, R.J. )

    1988-03-01

    The technique of Island blocking is being used more frequently since the advent of our new head and neck blocking techniques and the implementation of a newly devised lung protocol. The system presented affords the mould room personnel a quick and accurate means of island block fabrication without the constant remeasuring or subtle shifting to approximate correct placement. The cookie cutter is easily implemented into any department's existing block cutting techniques. The device is easily and inexpensively made either in a machine shop or acquired by contacting the author.

  7. Active cleaning technique device

    NASA Technical Reports Server (NTRS)

    Shannon, R. L.; Gillette, R. B.

    1973-01-01

    The objective of this program was to develop a laboratory demonstration model of an active cleaning technique (ACT) device. The principle of this device is based primarily on the technique for removing contaminants from optical surfaces. This active cleaning technique involves exposing contaminated surfaces to a plasma containing atomic oxygen or combinations of other reactive gases. The ACT device laboratory demonstration model incorporates, in addition to plasma cleaning, the means to operate the device as an ion source for sputtering experiments. The overall ACT device includes a plasma generation tube, an ion accelerator, a gas supply system, a RF power supply and a high voltage dc power supply.

  8. Electrical termination techniques

    NASA Technical Reports Server (NTRS)

    Oakey, W. E.; Schleicher, R. R.

    1976-01-01

    A technical review of high reliability electrical terminations for electronic equipment was made. Seven techniques were selected from this review for further investigation, experimental work, and preliminary testing. From the preliminary test results, four techniques were selected for final testing and evaluation. These four were: (1) induction soldering, (2) wire wrap, (3) percussive arc welding, and (4) resistance welding. Of these four, induction soldering was selected as the best technique in terms of minimizing operator errors, controlling temperature and time, minimizing joint contamination, and ultimately producing a reliable, uniform, and reusable electrical termination.

  9. Pattern recognition technique

    NASA Technical Reports Server (NTRS)

    Hong, J. P.

    1971-01-01

    Technique operates regardless of pattern rotation, translation or magnification and successfully detects out-of-register patterns. It improves accuracy and reduces cost of various optical character recognition devices and page readers and provides data input to computer.

  10. Small Scale Organic Techniques

    ERIC Educational Resources Information Center

    Horak, V.; Crist, DeLanson R.

    1975-01-01

    Discusses the advantages of using small scale experimentation in the undergraduate organic chemistry laboratory. Describes small scale filtration techniques as an example of a semi-micro method applied to small quantities of material. (MLH)

  11. The MST Radar Technique

    NASA Technical Reports Server (NTRS)

    Balsley, B. B.

    1985-01-01

    The past ten year have witnessed the development of a new radar technique to examine the structure and dynamics of the atmosphere between roughly 1 to 100 km on a continuous basis. The technique is known as the MST (for Mesosphere-Stratosphere-Troposphere) technique and is usable in all weather conditions, being unaffected by precipitation or cloud cover. MST radars make use of scattering from small scale structure in the atmospheric refractive index, with scales of the order of one-half the radar wavelength. Pertinent scale sizes for middle atmospheric studies typically range between a fraction of a meter and a few meters. The structure itself arises primarily from atmospheric turbulence. The technique is briefly described along with the meteorological parameters it measures.

  12. Apollo Onboard Navigation Techniques

    NASA Technical Reports Server (NTRS)

    Interbartolo, Michael

    2009-01-01

    This viewgraph presentation reviews basic navigation concepts, describes coordinate systems and identifies attitude determination techniques including Primary Guidance, Navigation and Control System (PGNCS) IMU management and Command and Service Module Stabilization and Control System/Lunar Module (LM) Abort Guidance System (AGS) attitude management. The presentation also identifies state vector determination techniques, including PGNCS coasting flight navigation, PGNCS powered flight navigation and LM AGS navigation.

  13. Next generation initiation techniques

    NASA Technical Reports Server (NTRS)

    Warner, Tom; Derber, John; Zupanski, Milija; Cohn, Steve; Verlinde, Hans

    1993-01-01

    Four-dimensional data assimilation strategies can generally be classified as either current or next generation, depending upon whether they are used operationally or not. Current-generation data-assimilation techniques are those that are presently used routinely in operational-forecasting or research applications. They can be classified into the following categories: intermittent assimilation, Newtonian relaxation, and physical initialization. It should be noted that these techniques are the subject of continued research, and their improvement will parallel the development of next generation techniques described by the other speakers. Next generation assimilation techniques are those that are under development but are not yet used operationally. Most of these procedures are derived from control theory or variational methods and primarily represent continuous assimilation approaches, in which the data and model dynamics are 'fitted' to each other in an optimal way. Another 'next generation' category is the initialization of convective-scale models. Intermittent assimilation systems use an objective analysis to combine all observations within a time window that is centered on the analysis time. Continuous first-generation assimilation systems are usually based on the Newtonian-relaxation or 'nudging' techniques. Physical initialization procedures generally involve the use of standard or nonstandard data to force some physical process in the model during an assimilation period. Under the topic of next-generation assimilation techniques, variational approaches are currently being actively developed. Variational approaches seek to minimize a cost or penalty function which measures a model's fit to observations, background fields and other imposed constraints. Alternatively, the Kalman filter technique, which is also under investigation as a data assimilation procedure for numerical weather prediction, can yield acceptable initial conditions for mesoscale models. The

  14. Sensorimotor System Measurement Techniques

    PubMed Central

    Riemann, Bryan L.; Myers, Joseph B.; Lephart, Scott M.

    2002-01-01

    Objective: To provide an overview of currently available sensorimotor assessment techniques. Data Sources: We drew information from an extensive review of the scientific literature conducted in the areas of proprioception, neuromuscular control, and motor control measurement. Literature searches were conducted using MEDLINE for the years 1965 to 1999 with the key words proprioception, somatosensory evoked potentials, nerve conduction testing, electromyography, muscle dynamometry, isometric, isokinetic, kinetic, kinematic, posture, equilibrium, balance, stiffness, neuromuscular, sensorimotor, and measurement. Additional sources were collected using the reference lists of identified articles. Data Synthesis: Sensorimotor measurement techniques are discussed with reference to the underlying physiologic mechanisms, influential factors and locations of the variable within the system, clinical research questions, limitations of the measurement technique, and directions for future research. Conclusions/Recommendations: The complex interactions and relationships among the individual components of the sensorimotor system make measuring and analyzing specific characteristics and functions difficult. Additionally, the specific assessment techniques used to measure a variable can influence attained results. Optimizing the application of sensorimotor research to clinical settings can, therefore, be best accomplished through the use of common nomenclature to describe underlying physiologic mechanisms and specific measurement techniques. PMID:16558672

  15. Neuronavigation. Principles. Surgical technique.

    PubMed

    Ivanov, Marcel; Ciurea, Alexandru Vlad

    2009-01-01

    Neuronavigation and stereotaxy are techniques designed to help neurosurgeons precisely localize different intracerebral pathological processes by using a set of preoperative images (CT, MRI, fMRI, PET, SPECT etc.). The development of computer assisted surgery was possible only after a significant technological progress, especially in the area of informatics and imagistics. The main indications of neuronavigation are represented by the targeting of small and deep intracerebral lesions and choosing the best way to treat them, in order to preserve the neurological function. Stereotaxis also allows lesioning or stimulation of basal ganglia for the treatment of movement disorders. These techniques can bring an important amount of confort both to the patient and to the neurosurgeon. Neuronavigation was introduced in Romania around 2003, in four neurosurgical centers. We present our five-years experience in neuronavigation and describe the main principles and surgical techniques.

  16. The MST Radar Technique

    NASA Technical Reports Server (NTRS)

    Roettger, J.

    1984-01-01

    The coherent radar technique is reviewed with special emphasis to mesosphere-stratosphere-troposphere (MST) radars operating in the VHF band. Some basic introduction to Doppler radar measurements and the radar equation is followed by an outline of the characteristics of atmospheric turbulence, viewed from the scattering and reflection processes of radar signals. Radar signal acquisition and preprocessing, namely coherent detection, digital sampling, pre-integration and coding, is briefly discussed. The data analysis is represented in terms of the correlation and spectrum analysis, yielding the essential parameters: power, signal-to-noise ratio, average and fluctuating velocity and persistency. The techniques to measure wind velocities, viz. the different modes of the Doppler method as well as the space antenna method are surveyed and the feasibilities of the MST radar interferometer technique are elucidated. A general view on the criteria to design phased array antennas is given. An outline of the hardware of a typical MST radar system is presented.

  17. [Foetal sampling techniques].

    PubMed

    Levy, R; Arfi, J-S; Daffos, F

    2003-06-01

    This article describes the current techniques of foetal sampling. All of them are actually ultrasound guided, and therefore generally very safe. Nevertheless, an elaborate learning process remains indispensable, in addition to a particular attention to the quality of the physician-patient dialogue. The choice of a technique depends on the indication and on the term of the pregnancy. The most frequently used technique is amniocentesis which presents a low risk of foetal loss, estimated between 0.2 and 0.5 percent. The interest of chorionic villus sampling is the possibility to obtain results at an earlier stage of pregnancy, with a lower risk taking when compared to early amniocentesis. We prefer the transabdominal chorionic villus sampling to the transvaginal. Foetal blood sampling is still required in some cases, but the risk of complications is higher--around 1 percent. PMID:12865196

  18. Novel Foraminal Expansion Technique

    PubMed Central

    Senturk, Salim; Ciplak, Mert; Oktenoglu, Tunc; Sasani, Mehdi; Egemen, Emrah; Yaman, Onur; Suzer, Tuncer

    2016-01-01

    The technique we describe was developed for cervical foraminal stenosis for cases in which a keyhole foraminotomy would not be effective. Many cervical stenosis cases are so severe that keyhole foraminotomy is not successful. However, the technique outlined in this study provides adequate enlargement of an entire cervical foraminal diameter. This study reports on a novel foraminal expansion technique. Linear drilling was performed in the middle of the facet joint. A small bone graft was placed between the divided lateral masses after distraction. A lateral mass stabilization was performed with screws and rods following the expansion procedure. A cervical foramen was linearly drilled medially to laterally, then expanded with small bone grafts, and a lateral mass instrumentation was added with surgery. The patient was well after the surgery. The novel foraminal expansion is an effective surgical method for severe foraminal stenosis. PMID:27559460

  19. Novel Foraminal Expansion Technique.

    PubMed

    Ozer, Ali Fahir; Senturk, Salim; Ciplak, Mert; Oktenoglu, Tunc; Sasani, Mehdi; Egemen, Emrah; Yaman, Onur; Suzer, Tuncer

    2016-08-01

    The technique we describe was developed for cervical foraminal stenosis for cases in which a keyhole foraminotomy would not be effective. Many cervical stenosis cases are so severe that keyhole foraminotomy is not successful. However, the technique outlined in this study provides adequate enlargement of an entire cervical foraminal diameter. This study reports on a novel foraminal expansion technique. Linear drilling was performed in the middle of the facet joint. A small bone graft was placed between the divided lateral masses after distraction. A lateral mass stabilization was performed with screws and rods following the expansion procedure. A cervical foramen was linearly drilled medially to laterally, then expanded with small bone grafts, and a lateral mass instrumentation was added with surgery. The patient was well after the surgery. The novel foraminal expansion is an effective surgical method for severe foraminal stenosis. PMID:27559460

  20. Neuronavigation. Principles. Surgical technique.

    PubMed

    Ivanov, Marcel; Ciurea, Alexandru Vlad

    2009-01-01

    Neuronavigation and stereotaxy are techniques designed to help neurosurgeons precisely localize different intracerebral pathological processes by using a set of preoperative images (CT, MRI, fMRI, PET, SPECT etc.). The development of computer assisted surgery was possible only after a significant technological progress, especially in the area of informatics and imagistics. The main indications of neuronavigation are represented by the targeting of small and deep intracerebral lesions and choosing the best way to treat them, in order to preserve the neurological function. Stereotaxis also allows lesioning or stimulation of basal ganglia for the treatment of movement disorders. These techniques can bring an important amount of confort both to the patient and to the neurosurgeon. Neuronavigation was introduced in Romania around 2003, in four neurosurgical centers. We present our five-years experience in neuronavigation and describe the main principles and surgical techniques. PMID:20108488

  1. Understanding PSK demodulation techniques

    NASA Astrophysics Data System (ADS)

    Steber, J. M.

    1984-03-01

    Various problems encountered in phase-shift keying (PSK) demodulation are discussed, and techniques are outlined for recovering suppressed carriers. In discussing demodulation techniques, it is pointed out that a PSK demodulation procedure can be divided into three major subsections, namely carrier recovery, timing recovery, and channel filtering. Descriptions are then given of the polarity loop and the remodulator. The remodulator generates a loop error signal that is proportional to the doubled phase error between the incoming phase and its estimate. Stochastically, the remodulator is equivalent to the polarity loop, or hard-limited Costas loop. A figure is included outlining a remodulation technique for QPSK carrier recovery and data extraction. Also discussed is the multiplier-filter-divide circuit, which is another method of QPSK carrier recovery used in high-rate burst-mode systems.

  2. Techniques for video indexing

    NASA Astrophysics Data System (ADS)

    Chen, C. Y. Roger; Meliksetian, Dikran S.; Liu, Larry J.; Chang, Martin C.

    1996-01-01

    A data model for long objects (such as video files) is introduced, to support general referencing structures, along with various system implementation strategies. Based on the data model, various indexing techniques for video are then introduced. A set of basic functionalities is described, including all the frame level control, indexing, and video clip editing. We show how the techniques can be used to automatically index video files based on closed captions with a typical video capture card, for both compressed and uncompressed video files. Applications are presented using those indexing techniques in security control and viewers' rating choice, general video search (from laser discs, CD ROMs, and regular disks), training videos, and video based user or system manuals.

  3. Novel Foraminal Expansion Technique.

    PubMed

    Ozer, Ali Fahir; Senturk, Salim; Ciplak, Mert; Oktenoglu, Tunc; Sasani, Mehdi; Egemen, Emrah; Yaman, Onur; Suzer, Tuncer

    2016-08-01

    The technique we describe was developed for cervical foraminal stenosis for cases in which a keyhole foraminotomy would not be effective. Many cervical stenosis cases are so severe that keyhole foraminotomy is not successful. However, the technique outlined in this study provides adequate enlargement of an entire cervical foraminal diameter. This study reports on a novel foraminal expansion technique. Linear drilling was performed in the middle of the facet joint. A small bone graft was placed between the divided lateral masses after distraction. A lateral mass stabilization was performed with screws and rods following the expansion procedure. A cervical foramen was linearly drilled medially to laterally, then expanded with small bone grafts, and a lateral mass instrumentation was added with surgery. The patient was well after the surgery. The novel foraminal expansion is an effective surgical method for severe foraminal stenosis.

  4. Relaxation Techniques for Trauma.

    PubMed

    Scotland-Coogan, Diane; Davis, Erin

    2016-01-01

    Physiological symptoms of posttraumatic stress disorder (PTSD) manifest as increased arousal and reactivity seen as anger outburst, irritability, reckless behavior with no concern for consequences, hypervigilance, sleep disturbance, and problems with focus (American Psychiatric Association, 2013 ). In seeking the most beneficial treatment for PTSD, consideration must be given to the anxiety response. Relaxation techniques are shown to help address the physiological manifestations of prolonged stress. The techniques addressed by the authors in this article include mindfulness, deep breathing, yoga, and meditation. By utilizing these techniques traditional therapies can be complemented. In addition, those who are averse to the traditional evidence-based practices or for those who have tried traditional therapies without success; these alternative interventions may assist in lessening physiological manifestations of PTSD. Future research studies assessing the benefits of these treatment modalities are warranted to provide empirical evidence to support the efficacy of these treatments. PMID:27119722

  5. Craniospinal irradiation techniques

    SciTech Connect

    Scarlatescu, Ioana Avram, Calin N.; Virag, Vasile

    2015-12-07

    In this paper we present one treatment plan for irradiation cases which involve a complex technique with multiple beams, using the 3D conformational technique. As the main purpose of radiotherapy is to administrate a precise dose into the tumor volume and protect as much as possible all the healthy tissues around it, for a case diagnosed with a primitive neuro ectoderm tumor, we have developed a new treatment plan, by controlling one of the two adjacent fields used at spinal field, in a way that avoids the fields superposition. Therefore, the risk of overdose is reduced by eliminating the field divergence.

  6. Stochastic Feedforward Control Technique

    NASA Technical Reports Server (NTRS)

    Halyo, Nesim

    1990-01-01

    Class of commanded trajectories modeled as stochastic process. Advanced Transport Operating Systems (ATOPS) research and development program conducted by NASA Langley Research Center aimed at developing capabilities for increases in capacities of airports, safe and accurate flight in adverse weather conditions including shear, winds, avoidance of wake vortexes, and reduced consumption of fuel. Advances in techniques for design of modern controls and increased capabilities of digital flight computers coupled with accurate guidance information from Microwave Landing System (MLS). Stochastic feedforward control technique developed within context of ATOPS program.

  7. Remote Raman measurement techniques

    NASA Technical Reports Server (NTRS)

    Leonard, D. A.

    1981-01-01

    The use of laser Raman measurement techniques in remote sensing applications is surveyed. A feasibility index is defined as a means to characterize the practicality of a given remote Raman measurement application. Specific applications of Raman scattering to the measurement of atmospheric water vapor profiles, methane plumes from liquid natural gas spills, and subsurface ocean temperature profiles are described. This paper will survey the use of laser Raman measurement techniques in remote sensing applications using as examples specific systems that the Computer Genetics Corporation (CGC) group has developed and engineered.

  8. Craniospinal irradiation techniques

    NASA Astrophysics Data System (ADS)

    Scarlatescu, Ioana; Virag, Vasile; Avram, Calin N.

    2015-12-01

    In this paper we present one treatment plan for irradiation cases which involve a complex technique with multiple beams, using the 3D conformational technique. As the main purpose of radiotherapy is to administrate a precise dose into the tumor volume and protect as much as possible all the healthy tissues around it, for a case diagnosed with a primitive neuro ectoderm tumor, we have developed a new treatment plan, by controlling one of the two adjacent fields used at spinal field, in a way that avoids the fields superposition. Therefore, the risk of overdose is reduced by eliminating the field divergence.

  9. Carbon isotope techniques

    SciTech Connect

    Coleman, D.C. ); Fry, B. )

    1991-01-01

    This book is a hands-on introduction to using carbon isotope tracers in experimental biology and ecology. It is a bench-top reference with protocols for the study of plants, animals, and soils. The {sup 11}C, {sup 12}C, {sup 13}C, and {sup 14}C carbon isotopes are considered and standard techniques are described by established authors. The compilation includes the following features: specific, well-established, user-oriented techniques; carbon cycles in plants, animals, soils, air, and water; isotopes in ecological research; examples and sample calculations.

  10. Effective Frequency Technique

    NASA Technical Reports Server (NTRS)

    Kirk, C. Laurence; Weng, Chi Y.

    2002-01-01

    An effective monochromatic frequency technique is described to represent the effects of finite spectral bandwidth for active and passive measurements centered on an absorption line, a trough region, or a slowly varying spectral feature. For Gaussian and rectangular laser line shapes, the effective frequency is shown to have a simple form which depends only on the instrumental line shape and bandwidth and not on the absorption line profile. The technique yields accuracies better than 0.1% for bandwidths less than 0.2 times the atmospheric line width.

  11. Gisting technique development

    NASA Astrophysics Data System (ADS)

    Bamberg, P. G.; Bahler, L. G.; Baker, J. M.; Kellett, H. G.

    1981-12-01

    This report documents the methods utilized to improve and simplify the procedure for operating reference templates and word models used in the key word recognition process. Commands necessary for the automatic generation of reference templates have been added and the procedure for word model generation has been automated. Test results show a modest performance improvement over previous methods. Recognition was improved with a 20-word English set from 33.5% to 41% operating at a threshold of 2.52 false alarms/hr/word. Techniques have also been developed for on-line reference generation that requires no auxiliary mass storage devices. These techniques are also described.

  12. Alexander Technique and Dance Technique: Applications in the Studio

    ERIC Educational Resources Information Center

    Nettl-Fiol, Rebecca

    2006-01-01

    Integrating principles from the Alexander Technique into a dance technique class can provide tools for facilitating a more coordinated use of the self. While the methodologies of Alexander Technique and dance technique may present differences, there are ways of applying the principles of Alexander within the context of a dance technique class that…

  13. Blood Typing--Technique.

    ERIC Educational Resources Information Center

    Johnstone, W. T., Jr.

    This instructional packet deals with the study of hematology. It is recommended for all high school students of biology. A general understanding of antigen-antibody reactions is necessary before attempting this learning activity. Behavioral objectives place emphasis on the techniques of and understanding of blood typing. The equipment and…

  14. Techniques in Adlerian Psychology.

    ERIC Educational Resources Information Center

    Carlson, Jon, Ed.; Slavik, Steven, Ed.

    This book is a collection of classic and recent papers (published between 1964 and 1994) reprinted from the "Journal of Juvenile Psychology""Individual Psychologist," and "Individual Psychology." Each of the five sections is introduced by the editor's comments. "General Techniques" contains the following articles: (1) "I-Thou Relationship Versus…

  15. Mathematical techniques: A compilation

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Articles on theoretical and applied mathematics are introduced. The articles cover information that might be of interest to workers in statistics and information theory, computational aids that could be used by scientists and engineers, and mathematical techniques for design and control.

  16. Creative Job Search Technique

    ERIC Educational Resources Information Center

    Canadian Vocational Journal, 1974

    1974-01-01

    Creative Job Search Technique is based on the premise that most people have never learned how to systematically look for a job. A person who is unemployed can be helped to take a hard look at his acquired skills and relate those skills to an employer's needs. (Author)

  17. The attribute measurement technique

    SciTech Connect

    Macarthur, Duncan W; Langner, Diana; Smith, Morag; Thron, Jonathan; Razinkov, Sergey; Livke, Alexander

    2010-01-01

    Any verification measurement performed on potentially classified nuclear material must satisfy two seemingly contradictory constraints. First and foremost, no classified information can be released. At the same time, the monitoring party must have confidence in the veracity of the measurement. An information barrier (IB) is included in the measurement system to protect the potentially classified information while allowing sufficient information transfer to occur for the monitoring party to gain confidence that the material being measured is consistent with the host's declarations, concerning that material. The attribute measurement technique incorporates an IB and addresses both concerns by measuring several attributes of the nuclear material and displaying unclassified results through green (indicating that the material does possess the specified attribute) and red (indicating that the material does not possess the specified attribute) lights. The attribute measurement technique has been implemented in the AVNG, an attribute measuring system described in other presentations at this conference. In this presentation, we will discuss four techniques used in the AVNG: (1) the 1B, (2) the attribute measurement technique, (3) the use of open and secure modes to increase confidence in the displayed results, and (4) the joint design as a method for addressing both host and monitor needs.

  18. Assessing Classroom Assessment Techniques

    ERIC Educational Resources Information Center

    Simpson-Beck, Victoria

    2011-01-01

    Classroom assessment techniques (CATs) are teaching strategies that provide formative assessments of student learning. It has been argued that the use of CATs enhances and improves student learning. Although the various types of CATs have been extensively documented and qualitatively studied, there appears to be little quantitative research…

  19. Art Appreciation and Technique.

    ERIC Educational Resources Information Center

    Dean, Diane R.; Milam, Debora

    1985-01-01

    Presents examples of independent study units for gifted high school students in a resource room setting. Both art appreciation and technique are covered in activities concerned with media (basics of pencil, India ink, pastels, crayons, oil, acrylics, and watercolors), subject matter (landscapes, animals, the human figure), design and illustration…

  20. Trick or Technique?

    ERIC Educational Resources Information Center

    Sheard, Michael

    2009-01-01

    More often than one might at first imagine, a simple trick involving integration by parts can be used to compute indefinite integrals in unexpected and amusing ways. A systematic look at the trick illuminates the question of whether the trick is useful enough to be called an actual technique of integration.

  1. Techniques for Vocal Health.

    ERIC Educational Resources Information Center

    Wiest, Lori

    1997-01-01

    Outlines a series of simple yet effective practices, techniques, and tips for improving the singing voice and minimizing stress on the vocal chords. Describes the four components for producing vocal sound: respiration, phonation, resonation, and articulation. Provides exercises for each and lists symptoms of sickness and vocal strain. (MJP)

  2. Murine Kidney Transplant Technique.

    PubMed

    Plenter, Robert; Jain, Swati; Ruller, Chelsea M; Nydam, Trevor L; Jani, Alkesh H

    2015-10-20

    The first mouse kidney transplant technique was published in 1973(1) by the Russell laboratory. Although it took some years for other labs to become proficient in and utilize this technique, it is now widely used by many laboratories around the world. A significant refinement to the original technique using the donor aorta to form the arterial anastomosis instead of the renal artery was developed and reported in 1993 by Kalina and Mottram (2) with a further advancement coming from the same laboratory in 1999 (3). While one can become proficient in this model, a search of the literature reveals that many labs still experience a high proportion of graft loss due to arterial thrombosis. We describe here a technique that was devised in our laboratory that vastly reduces the arterial thrombus reported by others (4,5). This is achieved by forming a heel-and-toe cuff of the donor infra-renal aorta that facilitates a larger anastomosis and straighter blood flow into the kidney.

  3. The Symbolic Identity Technique.

    ERIC Educational Resources Information Center

    Goud, Nelson H.

    2001-01-01

    Explains the role of symbols in attaining total psychic growth by applying concepts of C. Jung, R. Assagiolo, and L. Kubie. Describes a new strategy, the symbolic identity technique, which involves environmental exploration in a relaxed, receptive manner in order to discover something in the outer environment that reflects one's inner nature.…

  4. Values Concepts and Techniques.

    ERIC Educational Resources Information Center

    National Education Association, Washington, DC.

    This book contains 29 articles for elementary and secondary teachers dealing with fundamental concepts and teaching techniques in values education. Part one of the book deals with concepts. Louis E. Raths examines valuing and its relationship to freedom and intelligence. The cognitive developmental approach to moral education is discussed by…

  5. Correlative Techniques in Microscopy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Imaging is an important component in basic research, product development and understanding structure/function relationships in agricultural commodities and products. An array of microscopes and techniques can be used illustrate the structure and microchemistry of diverse samples. Examples of the var...

  6. Retroperitoneoscopy: the balloon technique.

    PubMed

    Gaur, D D

    1994-07-01

    Retroperitoneoscopy was performed in 101 patients using the author's recently described balloon technique. Various urological procedures, were undertaken including renoscopy and renal biopsy, para-aortic lymph node biopsy, varicocelectomy, ureterolithotomy, pyelolithotomy, pyeloplasty, nephrolithotomy, nephrectomy, decortication of renal cyst, adrenalectomy, pelvic lymphadenectomy and ligation of deep penile veins.

  7. Super Techniques for Teachers.

    ERIC Educational Resources Information Center

    Foley, Michael K.

    A variety of techniques can help a teacher create the atmosphere of a "quality circle," a Japanese management method in which each member of a group shares and contributes to the learning experience. "Creating a Commercial" allows students to create original oratory for presentation to the class. In "The Good News First," students improve their…

  8. Techniques of Efficient Reading.

    ERIC Educational Resources Information Center

    Brown, James I.

    To help students develop techniques which lead to maximum reading efficiency, it is first necessary to help them develop a positive self-image. Growing evidence is focusing attention on self-image as the crucial determiner of progress. Poor progess in reading at the elementary level leads to poor self-image, which in turn hinders the student in…

  9. Managerial Techniques in Educational Administration.

    ERIC Educational Resources Information Center

    Lane, John J.

    1983-01-01

    Management techniques developed during the past 20 years assume the rational bureaucratic model. School administration requires contingent techniques. Quality Circle, Theory Z, and the McKenzie 7-Framework are discussed as techniques to increase school productivity. (MD)

  10. Network acceleration techniques

    NASA Technical Reports Server (NTRS)

    Crowley, Patricia (Inventor); Awrach, James Michael (Inventor); Maccabe, Arthur Barney (Inventor)

    2012-01-01

    Splintered offloading techniques with receive batch processing are described for network acceleration. Such techniques offload specific functionality to a NIC while maintaining the bulk of the protocol processing in the host operating system ("OS"). The resulting protocol implementation allows the application to bypass the protocol processing of the received data. Such can be accomplished this by moving data from the NIC directly to the application through direct memory access ("DMA") and batch processing the receive headers in the host OS when the host OS is interrupted to perform other work. Batch processing receive headers allows the data path to be separated from the control path. Unlike operating system bypass, however, the operating system still fully manages the network resource and has relevant feedback about traffic and flows. Embodiments of the present disclosure can therefore address the challenges of networks with extreme bandwidth delay products (BWDP).

  11. Whole cell entrapment techniques.

    PubMed

    Trelles, Jorge A; Rivero, Cintia W

    2013-01-01

    Microbial whole cells are efficient, ecological, and low-cost catalysts that have been successfully applied in the pharmaceutical, environmental, and alimentary industries, among others. Microorganism immobilization is a good way to carry out the bioprocess under preparative conditions. The main advantages of this methodology lie in their high operational stability, easy upstream separation and bioprocess scale-up feasibility. Cell entrapment is the most widely used technique for whole cell immobilization. This technique-in which the cells are included within a rigid network-is porous enough to allow the diffusion of substrates and products, protects the selected microorganism from the reaction medium, and has high immobilization efficiency (100 % in most cases). PMID:23934817

  12. CTV rendezvous techniques

    NASA Astrophysics Data System (ADS)

    Jennings, Jerry L.; Anderson, Robert L.

    The cargo transfer vehicle (CTV) requires the capability to perform automated rendezvous with Space Station Freedom (SSF) using onboard sensors and algorithms. The current approach to CTV rendezvous applies techniques developed during the orbital maneuvering vehicle (OMV) program which have been mechanized for automatic, onboard execution. The initial catch up sequence can be described as a passive rendezvous without explicit time of arrival control. The ultimate requirement for this rendezvous technique is to place the CTV on the SSF V-bar axis at some specified downrange distance. The launch vehicle will use yaw steering during orbit injection to achieve the proper phantom plane for nodal biasing. This presentation describes the primary components of the CTV rendezvous scheme.

  13. CTV rendezvous techniques

    NASA Technical Reports Server (NTRS)

    Jennings, Jerry L.; Anderson, Robert L.

    1991-01-01

    The cargo transfer vehicle (CTV) requires the capability to perform automated rendezvous with Space Station Freedom (SSF) using onboard sensors and algorithms. The current approach to CTV rendezvous applies techniques developed during the orbital maneuvering vehicle (OMV) program which have been mechanized for automatic, onboard execution. The initial catch up sequence can be described as a passive rendezvous without explicit time of arrival control. The ultimate requirement for this rendezvous technique is to place the CTV on the SSF V-bar axis at some specified downrange distance. The launch vehicle will use yaw steering during orbit injection to achieve the proper phantom plane for nodal biasing. This presentation describes the primary components of the CTV rendezvous scheme.

  14. Airborne data acquisition techniques

    SciTech Connect

    Arro, A.A.

    1980-01-01

    The introduction of standards on acceptable procedures for assessing building heat loss has created a dilemma for the contractor performing airborne thermographic surveys. These standards impose specifications on instrumentation, data acquisition, recording, interpretation, and presentation. Under the standard, the contractor has both the obligation of compliance and the requirement of offering his services at a reasonable price. This paper discusses the various aspects of data acquisition for airborne thermographic surveys and various techniques to reduce the costs of this operation. These techniques include the calculation of flight parameters for economical data acquisition, the selection and use of maps for mission planning, and the use of meteorological forecasts for flight scheduling and the actual execution of the mission. The proper consideration of these factors will result in a cost effective data acquisition and will place the contractor in a very competitive position in offering airborne thermographic survey services.

  15. Electronic Packaging Techniques

    NASA Technical Reports Server (NTRS)

    1979-01-01

    A characteristic of aerospace system design is that equipment size and weight must always be kept to a minimum, even in small components such as electronic packages. The dictates of spacecraft design have spawned a number of high-density packaging techniques, among them methods of connecting circuits in printed wiring boards by processes called stitchbond welding and parallel gap welding. These processes help designers compress more components into less space; they also afford weight savings and lower production costs.

  16. Endoscopic Techniques in Tympanoplasty.

    PubMed

    Anzola, Jesus Franco; Nogueira, João Flávio

    2016-10-01

    The endoscope has transformed the way we observe, understand, and treat chronic ear disease. Improved view, exclusive transcanal techniques, assessment of ventilation routes and mastoid tissue preservation have led to decreased morbidity and functional enhancement of minimally invasive reconstruction of the middle ear. The philosophical identity of endoscopic ear surgery is evolving; new research, long-term results, and widespread acknowledgement of its postulates will undoubtedly define its role in otology. PMID:27565390

  17. Resin infiltration transfer technique

    DOEpatents

    Miller, David V.; Baranwal, Rita

    2009-12-08

    A process has been developed for fabricating composite structures using either reaction forming or polymer infiltration and pyrolysis techniques to densify the composite matrix. The matrix and reinforcement materials of choice can include, but are not limited to, silicon carbide (SiC) and zirconium carbide (ZrC). The novel process can be used to fabricate complex, net-shape or near-net shape, high-quality ceramic composites with a crack-free matrix.

  18. Synthetic battery cycling techniques

    NASA Technical Reports Server (NTRS)

    Leibecki, H.; Thaller, L. H.

    1982-01-01

    The group of techniques that as a class are referred to as synthetic battery cycling are described with reference to spacecraft battery systems. Synthetic battery cycling makes use of the capability of computer graphics to illustrate some of the basic characteristics of operation of individual electrodes within an operating electrochemical cell. It can also simulate the operation of an entire string of cells that are used as the energy storage subsystem of a power system.

  19. Numerical Techniques in Acoustics

    NASA Technical Reports Server (NTRS)

    Baumeister, K. J. (Compiler)

    1985-01-01

    This is the compilation of abstracts of the Numerical Techniques in Acoustics Forum held at the ASME's Winter Annual Meeting. This forum was for informal presentation and information exchange of ongoing acoustic work in finite elements, finite difference, boundary elements and other numerical approaches. As part of this forum, it was intended to allow the participants time to raise questions on unresolved problems and to generate discussions on possible approaches and methods of solution.

  20. Particle-mesh techniques

    NASA Technical Reports Server (NTRS)

    Macneice, Peter

    1995-01-01

    This is an introduction to numerical Particle-Mesh techniques, which are commonly used to model plasmas, gravitational N-body systems, and both compressible and incompressible fluids. The theory behind this approach is presented, and its practical implementation, both for serial and parallel machines, is discussed. This document is based on a four-hour lecture course presented by the author at the NASA Summer School for High Performance Computational Physics, held at Goddard Space Flight Center.

  1. Amoco technique gains support

    SciTech Connect

    1995-10-01

    Amoco Corp.`s low-cost horizontal drilling technique and equipment are gaining acceptance in the oilpatch after five years of design and fine-tuning work. The system is purely mechanical, and it`s designed to operate with a workover rig instead of a drilling rig. It`s engineered to drill short-radius horizontal wells with lateral sup to 1,000 feet, so far.

  2. Laparoscopic adrenalectomy: Surgical techniques

    PubMed Central

    Mellon, Matthew J.; Sethi, Amanjot; Sundaram, Chandru P.

    2008-01-01

    Since its first description in 1992, laparoscopic adrenalectomy has become the gold standard for the surgical treatment of most adrenal conditions. The benefits of a minimally invasive approach to adrenal resection such as decreased hospital stay, shorter recovery time and improved patient satisfaction are widely accepted. However, as this procedure becomes more widespread, critical steps of the operation must be maintained to ensure expected outcomes and success. This article reviews the surgical techniques for the laparoscopic adrenalectomy. PMID:19468527

  3. [Progress in imaging techniques].

    PubMed

    Mishima, Kazuaki; Otsuka, Tsukasa

    2013-05-01

    Today it is common to perform real-time diagnosis and treatment via live broadcast as a method of education and to spread new technology for diagnosis and therapy in medical fields. Live medical broadcasts have developed along with broadcast technology. In the early days, live video feeds were sent from operating rooms to classrooms and lecture halls in universities and hospitals. However, the development of imaging techniques and communication networks enabled live broadcasts that bi-directionally link operating rooms and meeting halls during scientific meetings and live demonstration courses. Live broadcasts therefore became an important method for education and the dissemination of new medical technologies. The development of imaging techniques has contributed to more realistic live broadcasts through such innovative techniques as three-dimensional viewing and higher-definition 4K technology. In the future, live broadcasts will be transmitted on personal computers using regular Internet connections. In addition to the enhancement of image delivery technology, it will also be necessary to examine the entire image delivery environment carefully, including issues of security and privacy of personal information.

  4. Foraminal height measurement techniques

    PubMed Central

    Phan, Kevin; Rao, Prashanth J.

    2015-01-01

    Background One of the proposed advantages of anterior lumbar interbody fusion (ALIF) is restoration of disc height and hence an indirect foraminal height restoration. While this proposed advantage is often quoted in the literature, there are few robust studies demonstrating restoration of foraminal volume. Thus, this study aimed to review the literature and discuss the progression and development of foramen measurement techniques. Methods A review of the literature was performed to identify studies which reported foraminal height and dimensions following fusion surgery in cadaveric models or patients. Results Techniques in prior studies used to quantify foraminal dimensions before and after fusion operations include analysis from plain radiographs, computed tomography (CT) scans and magnetic resonance imaging (MRI) scans. Recent studies have attempted to standardize foraminal dimension measurements with the use of orthogonal software, accelerator-based measurements and the use of multiple images for three-dimensional reconstruction of the foramen volume. Conclusions Consistent results have demonstrated significant increases in foraminal area and height following anterior lumbar interbody distraction, providing evidence that ALIF can indirectly increase foraminal height. Future studies should use standardized measurement approaches such as the Pedicle-to-Pedicle technique with CT or MRI images to determine changes in foraminal dimensions.

  5. Several new electrofocusing techniques.

    PubMed

    Ivory, Cornelius F

    2007-01-01

    The segregation and analysis of low-abundance proteins from complex biological fluids requires serial application of separation techniques that can simultaneously fractionate and concentrate solutes. In general, these techniques belong either to the family of displacement methods, e.g., ITP, or to the gradient methods, e.g., gradient-elution HPLC. IEF is a member of the subset of the gradient methods referred to as equilibrium gradient methods (EGM) and has the important property that, starting from an arbitrarily distributed initial state, evolves over time to a self-sharpening, stationary steady state. Until the introduction of counteracting chromatographic electrophoresis by O'Farrell in 1985, IEF was the only known electrokinetic technique with this property. Today, the sub-family of electrokinetic EGMs has at least half a dozen members and is slowly growing. This review describes some of the essential properties of the displacement methods, the EGMs and the non-EGMs, showing how they can be applied in microelectromechanical systems platforms, how their performance can be predicted and how new members with orthogonal properties may be added to the EGM family.

  6. Image compression technique

    DOEpatents

    Fu, C.Y.; Petrich, L.I.

    1997-03-25

    An image is compressed by identifying edge pixels of the image; creating a filled edge array of pixels each of the pixels in the filled edge array which corresponds to an edge pixel having a value equal to the value of a pixel of the image array selected in response to the edge pixel, and each of the pixels in the filled edge array which does not correspond to an edge pixel having a value which is a weighted average of the values of surrounding pixels in the filled edge array which do correspond to edge pixels; and subtracting the filled edge array from the image array to create a difference array. The edge file and the difference array are then separately compressed and transmitted or stored. The original image is later reconstructed by creating a preliminary array in response to the received edge file, and adding the preliminary array to the received difference array. Filling is accomplished by solving Laplace`s equation using a multi-grid technique. Contour and difference file coding techniques also are described. The techniques can be used in a method for processing a plurality of images by selecting a respective compression approach for each image, compressing each of the images according to the compression approach selected, and transmitting each of the images as compressed, in correspondence with an indication of the approach selected for the image. 16 figs.

  7. Image compression technique

    DOEpatents

    Fu, Chi-Yung; Petrich, Loren I.

    1997-01-01

    An image is compressed by identifying edge pixels of the image; creating a filled edge array of pixels each of the pixels in the filled edge array which corresponds to an edge pixel having a value equal to the value of a pixel of the image array selected in response to the edge pixel, and each of the pixels in the filled edge array which does not correspond to an edge pixel having a value which is a weighted average of the values of surrounding pixels in the filled edge array which do correspond to edge pixels; and subtracting the filled edge array from the image array to create a difference array. The edge file and the difference array are then separately compressed and transmitted or stored. The original image is later reconstructed by creating a preliminary array in response to the received edge file, and adding the preliminary array to the received difference array. Filling is accomplished by solving Laplace's equation using a multi-grid technique. Contour and difference file coding techniques also are described. The techniques can be used in a method for processing a plurality of images by selecting a respective compression approach for each image, compressing each of the images according to the compression approach selected, and transmitting each of the images as compressed, in correspondence with an indication of the approach selected for the image.

  8. Satellite altimeter calibration techniques

    NASA Technical Reports Server (NTRS)

    Kolenkiewicz, R.; Martin, C. F.

    1990-01-01

    This paper examines calibration techniques which can most effectively satisfy the requirements of future satellites carrying high-accuracy radar altimeters, such as the ESA ERS-1 and the NASA/CNES Topex/Poseidon satellites scheduled for launch during the next five years. The calibration accuracies and the advantages and disadvantages of the four currently proposed calibration techniques for over-water calibration are discussed: (1) a tide gauge on a tower at-sea and a nearby laser, (2) a laser and a tide gauge on an island with an offshore satellite pass and a geoid tie between the satellite ground track and the laser, (3) a tide gauge on a tower at-sea with satellite positioning from multiple lasers and a GPS, and (4) a laser and a tide gauge on a tower at-sea. Error budgets for these techniques, developed on the basis of state-of-the-art tracking systems, were found to have one sigma height uncertainties in the 2.8 to 4.9 cm range.

  9. Satellite altimeter calibration techniques

    NASA Astrophysics Data System (ADS)

    Kolenkiewicz, R.; Martin, C. F.

    This paper examines calibration techniques which can most effectively satisfy the requirements of future satellites carrying high-accuracy radar altimeters, such as the ESA ERS-1 and the NASA/CNES Topex/Poseidon satellites scheduled for launch during the next five years. The calibration accuracies and the advantages and disadvantages of the four currently proposed calibration techniques for over-water calibration are discussed: (1) a tide gauge on a tower at-sea and a nearby laser, (2) a laser and a tide gauge on an island with an offshore satellite pass and a geoid tie between the satellite ground track and the laser, (3) a tide gauge on a tower at-sea with satellite positioning from multiple lasers and a GPS, and (4) a laser and a tide gauge on a tower at-sea. Error budgets for these techniques, developed on the basis of state-of-the-art tracking systems, were found to have one sigma height uncertainties in the 2.8 to 4.9 cm range.

  10. Covariance mapping techniques

    NASA Astrophysics Data System (ADS)

    Frasinski, Leszek J.

    2016-08-01

    Recent technological advances in the generation of intense femtosecond pulses have made covariance mapping an attractive analytical technique. The laser pulses available are so intense that often thousands of ionisation and Coulomb explosion events will occur within each pulse. To understand the physics of these processes the photoelectrons and photoions need to be correlated, and covariance mapping is well suited for operating at the high counting rates of these laser sources. Partial covariance is particularly useful in experiments with x-ray free electron lasers, because it is capable of suppressing pulse fluctuation effects. A variety of covariance mapping methods is described: simple, partial (single- and multi-parameter), sliced, contingent and multi-dimensional. The relationship to coincidence techniques is discussed. Covariance mapping has been used in many areas of science and technology: inner-shell excitation and Auger decay, multiphoton and multielectron ionisation, time-of-flight and angle-resolved spectrometry, infrared spectroscopy, nuclear magnetic resonance imaging, stimulated Raman scattering, directional gamma ray sensing, welding diagnostics and brain connectivity studies (connectomics). This review gives practical advice for implementing the technique and interpreting the results, including its limitations and instrumental constraints. It also summarises recent theoretical studies, highlights unsolved problems and outlines a personal view on the most promising research directions.

  11. Foraminal height measurement techniques

    PubMed Central

    Phan, Kevin; Rao, Prashanth J.

    2015-01-01

    Background One of the proposed advantages of anterior lumbar interbody fusion (ALIF) is restoration of disc height and hence an indirect foraminal height restoration. While this proposed advantage is often quoted in the literature, there are few robust studies demonstrating restoration of foraminal volume. Thus, this study aimed to review the literature and discuss the progression and development of foramen measurement techniques. Methods A review of the literature was performed to identify studies which reported foraminal height and dimensions following fusion surgery in cadaveric models or patients. Results Techniques in prior studies used to quantify foraminal dimensions before and after fusion operations include analysis from plain radiographs, computed tomography (CT) scans and magnetic resonance imaging (MRI) scans. Recent studies have attempted to standardize foraminal dimension measurements with the use of orthogonal software, accelerator-based measurements and the use of multiple images for three-dimensional reconstruction of the foramen volume. Conclusions Consistent results have demonstrated significant increases in foraminal area and height following anterior lumbar interbody distraction, providing evidence that ALIF can indirectly increase foraminal height. Future studies should use standardized measurement approaches such as the Pedicle-to-Pedicle technique with CT or MRI images to determine changes in foraminal dimensions. PMID:27683677

  12. [Progress in imaging techniques].

    PubMed

    Mishima, Kazuaki; Otsuka, Tsukasa

    2013-05-01

    Today it is common to perform real-time diagnosis and treatment via live broadcast as a method of education and to spread new technology for diagnosis and therapy in medical fields. Live medical broadcasts have developed along with broadcast technology. In the early days, live video feeds were sent from operating rooms to classrooms and lecture halls in universities and hospitals. However, the development of imaging techniques and communication networks enabled live broadcasts that bi-directionally link operating rooms and meeting halls during scientific meetings and live demonstration courses. Live broadcasts therefore became an important method for education and the dissemination of new medical technologies. The development of imaging techniques has contributed to more realistic live broadcasts through such innovative techniques as three-dimensional viewing and higher-definition 4K technology. In the future, live broadcasts will be transmitted on personal computers using regular Internet connections. In addition to the enhancement of image delivery technology, it will also be necessary to examine the entire image delivery environment carefully, including issues of security and privacy of personal information. PMID:23789334

  13. Optical transmission techniques

    NASA Astrophysics Data System (ADS)

    Vasile, Irina B.; Filip, Luminita E.; Vasile, Alexandru

    2005-08-01

    An optical transmission system is a method of transferring information in the shape of bits or symbols for the case of digital systems, and of analogue waves for the case of analogue systems, between fixed points located on a fiber optics cable. Today and in the near future there are numerous such transmission techniques available. The increase of demands for data transfer from phone subscribers can be met only by means of digital techniques applied in the local network, in addition to the use of digital telephone exchange and of the digital transmission systems in the trees network. In order to increase the quantity of information transferred through one fiber, optical multiplexing techniques have been conceived and tested. The optical multiplexing is additional to the electrical signal multiplexing. The requests for the access network will become more and more complex, a larger flexibility and a wider band being needed. For the purpose of complying with these requests, the coherent simultaneous or alternative transmission towards the optical amplifiers represents a factor of technical progress. The multiplexing with wave length division allows for more channels to be transported through the same fiber with different wave lengths, in one or both directions.

  14. Applied ALARA techniques

    SciTech Connect

    Waggoner, L.O.

    1998-02-05

    The presentation focuses on some of the time-proven and new technologies being used to accomplish radiological work. These techniques can be applied at nuclear facilities to reduce radiation doses and protect the environment. The last reactor plants and processing facilities were shutdown and Hanford was given a new mission to put the facilities in a safe condition, decontaminate, and prepare them for decommissioning. The skills that were necessary to operate these facilities were different than the skills needed today to clean up Hanford. Workers were not familiar with many of the tools, equipment, and materials needed to accomplish:the new mission, which includes clean up of contaminated areas in and around all the facilities, recovery of reactor fuel from spent fuel pools, and the removal of millions of gallons of highly radioactive waste from 177 underground tanks. In addition, this work has to be done with a reduced number of workers and a smaller budget. At Hanford, facilities contain a myriad of radioactive isotopes that are 2048 located inside plant systems, underground tanks, and the soil. As cleanup work at Hanford began, it became obvious early that in order to get workers to apply ALARA and use hew tools and equipment to accomplish the radiological work it was necessary to plan the work in advance and get radiological control and/or ALARA committee personnel involved early in the planning process. Emphasis was placed on applying,ALARA techniques to reduce dose, limit contamination spread and minimize the amount of radioactive waste generated. Progress on the cleanup has,b6en steady and Hanford workers have learned to use different types of engineered controls and ALARA techniques to perform radiological work. The purpose of this presentation is to share the lessons learned on how Hanford is accomplishing radiological work.

  15. Optical Techniques in Optogenetics

    PubMed Central

    Mohanty, Samarendra K.; Lakshminarayananan, Vasudevan

    2015-01-01

    Optogenetics is an innovative technique for optical control of cells. This field has exploded over the past decade or so and has given rise to great advances in neuroscience. A variety of applications both from the basic and applied research have emerged, turning the early ideas into a powerful paradigm for cell biology, neuroscience and medical research. This review aims at highlighting the basic concepts that are essential for a comprehensive understanding of optogenetics and some important biological/biomedical applications. Further, emphasis is placed on advancement in optogenetics-associated light-based methods for controlling gene expression, spatially-controlled optogenetic stimulation and detection of cellular activities. PMID:26412943

  16. Monovision techniques for telerobots

    NASA Technical Reports Server (NTRS)

    Goode, P. W.; Carnils, K.

    1987-01-01

    The primary task of the vision sensor in a telerobotic system is to provide information about the position of the system's effector relative to objects of interest in its environment. The subtasks required to perform the primary task include image segmentation, object recognition, and object location and orientation in some coordinate system. The accomplishment of the vision task requires the appropriate processing tools and the system methodology to effectively apply the tools to the subtasks. The functional structure of the telerobotic vision system used in the Langley Research Center's Intelligent Systems Research Laboratory is discussed as well as two monovision techniques for accomplishing the vision subtasks.

  17. Synthetic battery cycling techniques

    NASA Technical Reports Server (NTRS)

    Leibecki, H. F.; Thaller, L. H.

    1982-01-01

    Synthetic battery cycling makes use of the fast growing capability of computer graphics to illustrate some of the basic characteristics of operation of individual electrodes within an operating electrochemical cell. It can also simulate the operation of an entire string of cells that are used as the energy storage subsystem of a power system. The group of techniques that as a class have been referred to as Synthetic Battery Cycling is developed in part to try to bridge the gap of understanding that exists between single cell characteristics and battery system behavior.

  18. Optical techniques in optogenetics

    NASA Astrophysics Data System (ADS)

    Mohanty, Samarendra K.; Lakshminarayananan, Vasudevan

    2015-07-01

    Optogenetics is an innovative technique for optical control of cells. This field has exploded over the past decade or so and has given rise to great advances in neuroscience. A variety of applications both from the basic and applied research have emerged, turning the early ideas into a powerful paradigm for cell biology, neuroscience, and medical research. This review aims at highlighting the basic concepts that are essential for a comprehensive understanding of optogenetics and some important biological/biomedical applications. Further, emphasis is placed on advancement in optogenetics-associated light-based methods for controlling gene expression, spatially controlled optogenetic stimulation and detection of cellular activities.

  19. Velocimetry Using Heterodyne Techniques

    SciTech Connect

    Strand, O T; Berzins, L V; Goosman, D R; Kuhlow, W W; Sargis, P D; Whitworth, T L

    2004-08-10

    At LLNL, we have been using heterodyne techniques for the past year and a half to measure velocities up to several kilometers-per-second on different types of experiments. We assembled this diagnostic, which we call the Heterodyne Velocimeter (HetV), using commercially available products developed for the communications industry. We use a 1550 nm fiber laser and single mode fibers to deliver light to and from the target. The return Doppler-shifted light is mixed with the original laser light to generate a beat frequency proportional to the velocity. At a velocity of 1000 m/s, the beat signal has a frequency of 1.29 GHz. We record the beat signals directly onto fast digitizers. The maximum velocity is limited by the bandwidth of the electronics and the sampling rate of the digitizers. The record length is limited by the amount of memory contained in the digitizers. This paper describes our approach to measuring velocities with this technique and presents recent data obtained with the HetV.

  20. Advanced Communication Processing Techniques

    NASA Astrophysics Data System (ADS)

    Scholtz, Robert A.

    This document contains the proceedings of the workshop Advanced Communication Processing Techniques, held May 14 to 17, 1989, near Ruidoso, New Mexico. Sponsored by the Army Research Office (under Contract DAAL03-89-G-0016) and organized by the Communication Sciences Institute of the University of Southern California, the workshop had as its objective to determine those applications of intelligent/adaptive communication signal processing that have been realized and to define areas of future research. We at the Communication Sciences Institute believe that there are two emerging areas which deserve considerably more study in the near future: (1) Modulation characterization, i.e., the automation of modulation format recognition so that a receiver can reliably demodulate a signal without using a priori information concerning the signal's structure, and (2) the incorporation of adaptive coding into communication links and networks. (Encoders and decoders which can operate with a wide variety of codes exist, but the way to utilize and control them in links and networks is an issue). To support these two new interest areas, one must have both a knowledge of (3) the kinds of channels and environments in which the systems must operate, and of (4) the latest adaptive equalization techniques which might be employed in these efforts.

  1. Modern quantitative schlieren techniques

    NASA Astrophysics Data System (ADS)

    Hargather, Michael; Settles, Gary

    2010-11-01

    Schlieren optical techniques have traditionally been used to qualitatively visualize refractive flowfields in transparent media. Modern schlieren optics, however, are increasingly focused on obtaining quantitative information such as temperature and density fields in a flow -- once the sole purview of interferometry -- without the need for coherent illumination. Quantitative data are obtained from schlieren images by integrating the measured refractive index gradient to obtain the refractive index field in an image. Ultimately this is converted to a density or temperature field using the Gladstone-Dale relationship, an equation of state, and geometry assumptions for the flowfield of interest. Several quantitative schlieren methods are reviewed here, including background-oriented schlieren (BOS), schlieren using a weak lens as a "standard," and "rainbow schlieren." Results are presented for the application of these techniques to measure density and temperature fields across a supersonic turbulent boundary layer and a low-speed free-convection boundary layer in air. Modern equipment, including digital cameras, LED light sources, and computer software that make this possible are also discussed.

  2. Code Optimization Techniques

    SciTech Connect

    MAGEE,GLEN I.

    2000-08-03

    Computers transfer data in a number of different ways. Whether through a serial port, a parallel port, over a modem, over an ethernet cable, or internally from a hard disk to memory, some data will be lost. To compensate for that loss, numerous error detection and correction algorithms have been developed. One of the most common error correction codes is the Reed-Solomon code, which is a special subset of BCH (Bose-Chaudhuri-Hocquenghem) linear cyclic block codes. In the AURA project, an unmanned aircraft sends the data it collects back to earth so it can be analyzed during flight and possible flight modifications made. To counter possible data corruption during transmission, the data is encoded using a multi-block Reed-Solomon implementation with a possibly shortened final block. In order to maximize the amount of data transmitted, it was necessary to reduce the computation time of a Reed-Solomon encoding to three percent of the processor's time. To achieve such a reduction, many code optimization techniques were employed. This paper outlines the steps taken to reduce the processing time of a Reed-Solomon encoding and the insight into modern optimization techniques gained from the experience.

  3. Landing techniques in volleyball.

    PubMed

    Lobietti, Roberto; Coleman, Simon; Pizzichillo, Eduardo; Merni, Franco

    2010-11-01

    Knee injuries such as anterior cruciate ligament lesions and patellar tendonitis are very frequent in volleyball, and are often attributed to micro traumas that occur during the landing phase of airborne actions. The aim of the present study was to compare different jumping activities during official men's and women's volleyball games. Twelve top-level matches from the Italian men's and women's professional leagues were analysed. The jumps performed during the games were classified according to the landing technique used by the player (left or right foot or both feet together), court position, and ball trajectory. Chi-square analyses were performed to detect differences in landing techniques between the sexes, court positions, and trajectories when serving, attacking, blocking, and setting. Significant differences (P < 0.05) were found between the sexes for block, set, and spike but not for the jump serve. The frequency of landings on one foot was related to court position and the trajectory of the sets: when spiking faster sets, the players were more likely to use a one-footed landing. The present results should help coaches and physiotherapists to devise appropriate training and prevention programmes, and reveal the need for further detailed biomechanical investigations of the relationships between landings and knee injuries. PMID:20967671

  4. Image Improvement Techniques

    NASA Astrophysics Data System (ADS)

    Shine, R. A.

    1997-05-01

    Over the last decade, a repertoire of techniques have been developed and/or refined to improve the quality of high spatial resolution solar movies taken from ground based observatories. These include real time image motion corrections, frame selection, phase diversity measurements of the wavefront, and extensive post processing to partially remove atmospheric distortion. Their practical application has been made possible by the increasing availability and decreasing cost of large CCD's with fast digital readouts and high speed computer workstations with large memories. Most successful have been broad band (0.3 to 10 nm) filtergram movies which can use exposure times of 10 to 30 ms, short enough to ``freeze'' atmospheric motions. Even so, only a handful of movies with excellent image quality for more than a hour have been obtained to date. Narrowband filtergrams (about 0.01 nm), such as those required for constructing magnetograms and Dopplergrams, have been more challenging although some single images approach the quality of the best continuum images. Some promising new techniques and instruments, together with persistence and good luck, should continue the progress made in the last several years.

  5. Advanced Coating Removal Techniques

    NASA Technical Reports Server (NTRS)

    Seibert, Jon

    2006-01-01

    An important step in the repair and protection against corrosion damage is the safe removal of the oxidation and protective coatings without further damaging the integrity of the substrate. Two such methods that are proving to be safe and effective in this task are liquid nitrogen and laser removal operations. Laser technology used for the removal of protective coatings is currently being researched and implemented in various areas of the aerospace industry. Delivering thousands of focused energy pulses, the laser ablates the coating surface by heating and dissolving the material applied to the substrate. The metal substrate will reflect the laser and redirect the energy to any remaining protective coating, thus preventing any collateral damage the substrate may suffer throughout the process. Liquid nitrogen jets are comparable to blasting with an ultra high-pressure water jet but without the residual liquid that requires collection and removal .As the liquid nitrogen reaches the surface it is transformed into gaseous nitrogen and reenters the atmosphere without any contamination to surrounding hardware. These innovative technologies simplify corrosion repair by eliminating hazardous chemicals and repetitive manual labor from the coating removal process. One very significant advantage is the reduction of particulate contamination exposure to personnel. With the removal of coatings adjacent to sensitive flight hardware, a benefit of each technique for the space program is that no contamination such as beads, water, or sanding residue is left behind when the job is finished. One primary concern is the safe removal of coatings from thin aluminum honeycomb face sheet. NASA recently conducted thermal testing on liquid nitrogen systems and found that no damage occurred on 1/6", aluminum substrates. Wright Patterson Air Force Base in conjunction with Boeing and NASA is currently testing the laser remOval technique for process qualification. Other applications of liquid

  6. Micro- and Nanofabrication Techniques

    NASA Astrophysics Data System (ADS)

    Fermon, C.

    This chapter is intended to give readers a brief overview of the numerous techniques involved in the fabrication of small magnetic devices. Until recently there has been a wide distinction between semi-conductor engineering and metallic and magnetic devices fabrication, the main reason being due to the huge investments in terms of money and manpower devoted to semiconductors rather than real technical limitations. With the advent of spin electronics, the number of metal and magnetic devices are increasing and in some instances, semiconductor and magnetic device fabrication have started to merge and are currently the topic of intensive research in some areas (e.g. in MRAMs). In the future it is anticipated, that metal and magnetic devices will be further employed at an accelerated pace in the electronics and computing sectors due to their inherent advantages, e.g. smaller, faster, more powerful non-volatile memories.

  7. [Therapeutic education didactic techniques].

    PubMed

    Valverde, Maite; Vidal, Mercè; Jansa, Margarida

    2012-10-01

    This article includes an introduction to the role of Therapeutic Education for Diabetes treatment according to the recommendations of the American Diabetes Association (ADA), the Diabetes Education Study Group (DESG) of the "European Association for Study of Diabetes (EASD) and the clinical Practice Guidelines (CPG) of the Spanish Ministry of Health. We analyze theoretical models and the differences between teaching vs. learning as well as current trends (including Internet), that can facilitate meaningful learning of people with diabetes and their families and relatives. We analyze the differences, similarities, advantages and disadvantages of individual and group education. Finally, we describe different educational techniques (metaplan, case method, brainstorming, role playing, games, seminars, autobiography, forums, chats,..) applicable to individual, group or virtual education and its application depending on the learning objective.

  8. Introduction to Neutron Techniques

    NASA Astrophysics Data System (ADS)

    Eckold, Götz; Schober, Helmut

    Neutron scattering is one of the most powerful methods for the detailed investigation of condensed matter. Not only are structures from atomic to mesoscopic scales accessible, but also can dynamical properties of atoms, molecules, magnetic moments etc. be investigated. The prominent properties of neutrons with wavelengths of the order of atomic dimensions and, at the same time, frequencies of the order of characteristic vibrational frequencies allow us to investigate the space-time behavior of condensed matter on a microscopic scale over many decades. A good number of different and most efficient experimental techniques have been developed for different fields of application. Within this introductory chapter, we would like to provide the reader with a brief review about the main achievements in instrumentation without going into specific details, that may be found in the specialized literature.

  9. Technique for microswitch manufacture

    NASA Astrophysics Data System (ADS)

    Kitamura, T.; Kiyoyama, S.

    1983-05-01

    A five-step technique for microswitch manufacture is described: (1) A clad board is inlaid with a precious metal and the board is pressed. (2) One end of the fixed contact containing a precious metal inlay section is curved, and this edge of the precious metal inlay section becomes a fixed contact. (3) Inserts are formed in the unit body and terminal strips are placed through the top and bottom of the base and held. (4) The unit body is held by the base and the sequential contact strips are cut off. (5) Movable stripes are attached to the support of the terminal strips on the movable side and movable contacts are placed opposite the fixed contacts.

  10. Techniques for fire detection

    NASA Technical Reports Server (NTRS)

    Bukowski, Richard W.

    1987-01-01

    An overview is given of the basis for an analysis of combustable materials and potential ignition sources in a spacecraft. First, the burning process is discussed in terms of the production of the fire signatures normally associated with detection devices. These include convected and radiated thermal energy, particulates, and gases. Second, the transport processes associated with the movement of these from the fire to the detector, along with the important phenomena which cause the level of these signatures to be reduced, are described. Third, the operating characteristics of the individual types of detectors which influence their response to signals, are presented. Finally, vulnerability analysis using predictive fire modeling techniques is discussed as a means to establish the necessary response of the detection system to provide the level of protection required in the application.

  11. Technique for microswitch manufacture

    NASA Technical Reports Server (NTRS)

    Kitamura, T.; Kiyoyama, S.

    1983-01-01

    A five-step technique for microswitch manufacture is described: (1) A clad board is inlaid with a precious metal and the board is pressed. (2) One end of the fixed contact containing a precious metal inlay section is curved, and this edge of the precious metal inlay section becomes a fixed contact. (3) Inserts are formed in the unit body and terminal strips are placed through the top and bottom of the base and held. (4) The unit body is held by the base and the sequential contact strips are cut off. (5) Movable stripes are attached to the support of the terminal strips on the movable side and movable contacts are placed opposite the fixed contacts.

  12. Extended Ewald summation technique

    NASA Astrophysics Data System (ADS)

    Kylänpää, Ilkka; Räsänen, Esa

    2016-09-01

    We present a technique to improve the accuracy and to reduce the computational labor in the calculation of long-range interactions in systems with periodic boundary conditions. We extend the well-known Ewald method by using a linear combination of screening Gaussian charge distributions instead of only one. This enables us to find faster converging real-space and reciprocal space summations. The combined simplicity and efficiency of our method is demonstrated, and the scheme is readily applicable to large-scale periodic simulations, classical as well as quantum. Moreover, apart from the required a priori optimization the method is straightforward to include in most routines based on the Ewald method within, e.g., density-functional, molecular dynamics, and quantum Monte Carlo calculations.

  13. Thermoelastic vibration test techniques

    NASA Technical Reports Server (NTRS)

    Kehoe, Michael W.; Snyder, H. Todd

    1991-01-01

    The structural integrity of proposed high speed aircraft can be seriously affected by the extremely high surface temperatures and large temperature gradients throughout the vehicle's structure. Variations in the structure's elastic characteristics as a result of thermal effects can be observed by changes in vibration frequency, damping, and mode shape. Analysis codes that predict these changes must be correlated and verified with experimental data. The experimental modal test techniques and procedures used to conduct uniform, nonuniform, and transient thermoelastic vibration tests are presented. Experimental setup and elevated temperature instrumentation considerations are also discussed. Modal data for a 12 by 50 inch aluminum plate heated to a temperature of 475 F are presented. These data show the effect of heat on the plate's modal characteristics. The results indicated that frequency decreased, damping increased, and mode shape remained unchanged as the temperature of the plate was increased.

  14. Quantitative SPECT techniques.

    PubMed

    Watson, D D

    1999-07-01

    Quantitative imaging involves first, a set of measurements that characterize an image. There are several variations of technique, but the basic measurements that are used for single photon emission computed tomography (SPECT) perfusion images are reasonably standardized. Quantification currently provides only relative tracer activity within the myocardial regions defined by an individual SPECT acquisition. Absolute quantification is still a work in progress. Quantitative comparison of absolute changes in tracer uptake comparing a stress and rest study or preintervention and postintervention study would be useful and could be done, but most commercial systems do not maintain the data normalization that is necessary for this. Measurements of regional and global function are now possible with electrocardiography (ECG) gating, and this provides clinically useful adjunctive data. Techniques for measuring ventricular function are evolving and promise to provide clinically useful accuracy. The computer can classify images as normal or abnormal by comparison with a normal database. The criteria for this classification involve more than just checking the normal limits. The images should be analyzed to measure how far they deviate from normal, and this information can be used in conjunction with pretest likelihood to indicate the level of statistical certainty that an individual patient has a true positive or true negative test. The interface between the computer and the clinician interpreter is an important part of the process. Especially when both perfusion and function are being determined, the ability of the interpreter to correctly assimilate the data is essential to the use of the quantitative process. As we become more facile with performing and recording objective measurements, the significance of the measurements in terms of risk evaluation, viability assessment, and outcome should be continually enhanced. PMID:10433336

  15. SAUNA—a system for automatic sampling, processing, and analysis of radioactive xenon

    NASA Astrophysics Data System (ADS)

    Ringbom, A.; Larson, T.; Axelsson, A.; Elmgren, K.; Johansson, C.

    2003-08-01

    A system for automatic sampling, processing, and analysis of atmospheric radioxenon has been developed. From an air sample of about 7 m3 collected during 12 h, 0.5 cm3 of xenon is extracted, and the atmospheric activities from the four xenon isotopes 133Xe, 135Xe, 131mXe, and 133mXe are determined with a beta-gamma coincidence technique. The collection is performed using activated charcoal and molecular sieves at ambient temperature. The sample preparation and quantification are performed using preparative gas chromatography. The system was tested under routine conditions for a 5-month period, with average minimum detectable concentrations below 1 mBq/ m3 for all four isotopes.

  16. Local blood flow, cerebrovascular autoregulation and CO2 responsiveness in the rabbit hypothalamus

    PubMed Central

    Cranston, W. I.; Rosendorff, C.

    1971-01-01

    1. Local blood flow has been measured in the hypothalamus and other areas of the brain in the conscious rabbit, by measuring the rate of clearance of small volumes (2·5-10 μl.) of a saline solution of the inert tracer 133Xe injected locally. 2. Increasing the arterial PCO2 caused a mean rise in the hypothalamic blood flow of 34%. 3. The hypothalamic blood flow remained relatively constant over a mean arterial blood pressure range of 41-140 mm Hg. 4. Hypothalamic blood flow was relatively unaffected by anaesthesia with intravenous pentobarbitone; by contrast, blood flow in the cerebral cortex was greatly reduced. 5. It is concluded that the technique is a valid and useful one, since CO2 responsiveness and autoregulation is maintained. Different areas of grey matter have different flow rates, and vary in their responsiveness to barbiturate anaesthesia. PMID:5090987

  17. INGAS: Iranian Noble Gas Analyzing System for radioxenon measurement

    NASA Astrophysics Data System (ADS)

    Doost-Mohammadi, V.; Afarideh, H.; Etaati, G. R.; Safari, M. J.; Rouhi, H.

    2016-03-01

    In this article, Iranian Noble Gas Analyzing System (INGAS) will be introduced. This system is based on beta-gamma coincidence technique and consists of a well-type NaI(Tl) as gamma or X radiation detector and a cylindrical plastic scintillator to detect beta or conversion electron. Standard NIM modules were utilized to detect coincidence events of detectors. Both the beta and gamma detectors were appropriately calibrated. The efficiency curve of gamma detector for volume geometry was obtained by comparing the results of gamma point sources measurements and simulations of GATE V7.0 Monte Carlo code. The performance of detection system was checked by injection of 222Rn and 131mXe gaseous source in the detection cell. The minimum detectable activity of the system for 133Xe is 1.240±0.024 mBq for 24 h measurement time.

  18. Task-based strategy for optimized contrast enhanced breast imaging: analysis of six imaging techniques for mammography and tomosynthesis

    NASA Astrophysics Data System (ADS)

    Ikejimba, Lynda; Kiarashi, Nooshin; Lin, Yuan; Chen, Baiyu; Ghate, Sujata V.; Zerhouni, Moustafa; Samei, Ehsan; Lo, Joseph Y.

    2012-03-01

    Digital breast tomosynthesis (DBT) is a novel x-ray imaging technique that provides 3D structural information of the breast. In contrast to 2D mammography, DBT minimizes tissue overlap potentially improving cancer detection and reducing number of unnecessary recalls. The addition of a contrast agent to DBT and mammography for lesion enhancement has the benefit of providing functional information of a lesion, as lesion contrast uptake and washout patterns may help differentiate between benign and malignant tumors. This study used a task-based method to determine the optimal imaging approach by analyzing six imaging paradigms in terms of their ability to resolve iodine at a given dose: contrast enhanced mammography and tomosynthesis, temporal subtraction mammography and tomosynthesis, and dual energy subtraction mammography and tomosynthesis. Imaging performance was characterized using a detectability index d', derived from the system task transfer function (TTF), an imaging task, iodine contrast, and the noise power spectrum (NPS). The task modeled a 5 mm lesion containing iodine concentrations between 2.1 mg/cc and 8.6 mg/cc. TTF was obtained using an edge phantom, and the NPS was measured over several exposure levels, energies, and target-filter combinations. Using a structured CIRS phantom, d' was generated as a function of dose and iodine concentration. In general, higher dose gave higher d', but for the lowest iodine concentration and lowest dose, dual energy subtraction tomosynthesis and temporal subtraction tomosynthesis demonstrated the highest performance.

  19. Patterns of pulmonary perfusion scans in normal subjects. IV. The prevalence of abnormal scans in smokers 30 to 49 years of age

    SciTech Connect

    Fedullo, P.F.; Kapitan, K.S.; Brewer, N.S.; Ashburn, W.L.; Hartman, M.T.; Moser, K.M.

    1989-05-01

    The usefulness of ventilation-perfusion scans in the diagnosis of pulmonary embolism is limited by the wide range of pulmonary diseases that are associated with abnormal scans, and by the largely undetermined prevalence of abnormal scans in persons without cardiopulmonary disease. In prior studies, we found perfusion defects to be rarely present in young persons and in older nonsmokers. To determine if normal older smokers have a higher prevalence of abnormal ventilation and perfusion scans, we performed six-view /sup 99m/Tc perfusion (Q) scans and /sup 133/Xe ventilation (V) scans in 40 subjects 30 to 49 yr of age who had no known cardiopulmonary disease. Each subject had undergone a history, physical examination, electrocardiogram, spirometry, and posteroanterior chest roentgenogram prior to scanning. All V and Q scans were interpreted blindly and independently by two experienced readers. No subject demonstrated a lobar or segmental defect on two views. One subject had a matched subsegmental defect, and one subject had delayed washout from a subsegmental area of the right upper lobe during V scanning, with a normal Q scan. We conclude that abnormal V and Q scans are uncommon among normal smokers 30 to 49 yr of age.

  20. Patterns of pulmonary perfusion scans in normal subjects

    SciTech Connect

    Wallace, J.M.; Moser, K.M.; Hartman, M.T.; Ashburn, W.L.

    1981-01-01

    A vital factor conditioning the usage of the pulmonary perfusion (Q) scan in the evaluation of patients suspected of pulmonary embolism is the prevalence of abnormal Q scans in subjects free of cardiopulmonary disease. Because this prevalence has not been well defined, we performed Q scans in 80 nonsmoking subjects 18 to 29 yr of age having no known active cardiopulmonary disease. Each subject underwent a history, physical examination, electrocardiogram, spirometry, and PA chest roentgenogram, followed by a 6-view Q scan. Two subjects in whom a Q defect was suspected underwent a /sup 133/Xe equilibrium-washout ventilation (V) scan. All Q scans were interpreted blindly and independently by 2 experienced readers. Seventy-nine of the 80 Q scans were read as normal. No subject demonstrated a lobar or segmental defect. One of the 80 subjects, who had a mild pectus excavatum, had a left upper lobe subsegmental defect, which was not seen on the V scan. Based on the statistical analysis of these data, no more than 3.68% of normal nonsmoking persons in this age group may have a lobar or segmental Q scan defect and no more than 6.77% may have a subsegmental defect (with 95% confidence). Therefore, our study indicated that Q scan defects, particularly lobar or segmental, are rarely present among normal nonsmokers in this age group.

  1. Tissue/blood partition coefficients for xenon in various adipose tissue depots in man.

    PubMed

    Bülow, J; Jelnes, R; Astrup, A; Madsen, J; Vilmann, P

    1987-02-01

    Tissue/blood partition coefficients (lambda) for xenon were calculated for subcutaneous adipose tissue from the abdominal wall and the thigh, and for the perirenal adipose tissue after chemical analysis of the tissues for lipid, water and protein content. The lambda in the perirenal tissue was found to correlate linearly to the relative body weight (RBW) in per cent with the regression equation lambda = 0.045 . RBW + 0.99. The subcutaneous lambda on the abdomen correlated linearly to the local skinfold thickness (SFT) with the equation lambda = 0.22 SFT + 2.99. Similarly lambda on the thigh correlated to SFT with the equation lambda = 0.20 . SFT + 4.63. It is concluded that the previously accepted lambda value of 10 is generally too high in perirenal as well as in subcutaneous tissue. Thus, by application of the present regression equations, it is possible to obtain more exact estimates of the adipose tissue blood flow measured with the 133Xe wash-out method.

  2. Regulation of pulpal blood flow

    SciTech Connect

    Kim, S.

    1985-04-01

    The regulation of blood flow of the dental pulp was investigated in dogs and rats anesthetized with sodium pentobarbital. Pulpal blood flow was altered by variations of local and systemic hemodynamics. Macrocirculatory blood flow (ml/min/100 g) in the dental pulp was measured with both the /sup 133/Xe washout and the 15-microns radioisotope-labeled microsphere injection methods on the canine teeth of dogs, to provide a comparison of the two methods in the same tooth. Microcirculatory studies were conducted in the rat incisor tooth with microscopic determination of the vascular pattern, RBC velocity, and intravascular volumetric flow distribution. Pulpal resistance vessels have alpha- and beta-adrenergic receptors. Activation of alpha-receptors by intra-arterial injection of norepinephrine (NE) caused both a reduction in macrocirculatory Qp in dogs and decreases in arteriolar and venular diameters and intravascular volumetric flow (Qi) in rats. These responses were blocked by the alpha-antagonist PBZ. Activation of beta-receptors by intra-arterial injection of isoproterenal (ISO) caused a paradoxical reduction of Qp in dogs. In rats, ISO caused a transient increase in arteriolar Qi followed by a flow reduction; arteriolar dilation was accompanied by venular constriction. These macrocirculatory and microcirculatory responses to ISO were blocked by the alpha-antagonist propranolol.

  3. Single-photon tomographic determination of regional cerebral blood flow in psychiatric disorders

    SciTech Connect

    Devous, M.D. Sr.; Rush, A.J.; Schlesser, M.A.; Debus, J.; Raese, J.D.; Chehabi, H.H.; Bonte, F.J.

    1984-01-01

    Regional cerebral blood flow (rCBF) was measured by single-photon emission computed tomography (SPECT) of 133-Xe washout in 29 normal volunteers, 22 unipolar endogenous depressives (UPE), 9 unipolar nonendogenous depressives (UPNE), 13 bipolar depressed patients (BPD), and 14 schizophrenic patients (SCHZ). RCBF was measured 2 and 6 cm above and parallel to the cantho-meatal line and quantitated in 14 gray matter regions. Most subjects were drug-free for 4-14 days. Diagnoses were made by experienced clinicians employing the Research Diagnostic Criteria, the Hamilton Rating Scale, and the dexamethasone suppression test. SCHZ were rated with the Brief Psychiatric Rating Scale. UPE had reduced flow compared to normals in the right parietal and temporal lobes and a nonsignificant trend toward left temporal flow reductions. UPNE were not different from normal or other patient groups. BPD had significant flow elevations in the left hemisphere relative to normal, and in both hemispheres relative to UPE. SCHZ were not significantly different from normal or other patient groups. Anterior-posterior flow shifts were evaluated by subtracting parietal or temporal flows from frontal flows. SCHZ demonstrated a greater posterior shift (lower relative frontal lobe flow) in comparison to both UPE and UPNE. The most significant regional flow abnormalities were observed as frontal flow reductions in individual SCHZ, although these were not significant in the whole group in comparison to normal.

  4. Cerebral blood flow tomography with xenon-133

    SciTech Connect

    Lassen, N.A.

    1985-10-01

    Cerebral blood flow (CBF) can be measured tomographically by inhalation of Xenon-/sup 133/. The calculation is based on taking a sequence of tomograms during the wash-in and wash-out phase of the tracer. Due to the dynamic nature of the process, a highly sensitive and fast moving single photon emission computed tomograph (SPECT) is required. Two brain-dedicated SPECT systems designed for this purpose are mentioned, and the method is described with special reference to the limitations inherent in the soft energy of the 133Xe primary photons. CBF tomography can be used for a multitude of clinical and investigative purposes. This article discusses in particular its use for the selection of patients with carotid occlusion for extracranial/intracranial bypass surgery, for detection of severe arterial spasm after aneurysm bleeding, and for detection of low flow areas during severe migraine attacks. The use of other tracers for CBF tomography using SPECT is summarized with emphasis on the /sup 99m/Tc chelates that freely pass the intact blood-brain barrier. The highly sensitive brain-dedicated SPECT systems described are a prerequisite for achieving high resolution tomograms with such tracers.

  5. Laser Scar Management Technique

    PubMed Central

    Ohshiro, Toshio; Sasaki, Katsumi

    2013-01-01

    Background and Aims: Scars are common and cause functional problems and psychological morbidity. Recent advances in optical technologies have produced various laser systems capable of revising the appearance of scars from various etiologies to optimize their appearance. Methods: Laser treatment can commence as early as the time of the initial injury and as late as several years after the injury. Several optical technologies are currently available and combined laser/light treatments are required for treatment of scars. Since 2006, we have set up a scar management department in our clinic and more than 2000 patients have been treated by our combined laser irradiation techniques. Herein, we review several available light technologies for treatment of surgical, traumatic, and inflammatory scars, and discuss our combined laser treatment of scars, based upon our clinical experience. Results and Conclusions: Because scars have a variety of potential aetiologies and take a number of forms, no single approach can consistenty provide good scar treatment and management. The combination of laser and devices is essential, the choice of wavelength and approach being dictated by each patient as an individual. PMID:24511202

  6. Nozzle fabrication technique

    NASA Technical Reports Server (NTRS)

    Wells, Dennis L. (Inventor)

    1991-01-01

    A block of electrically conductive material which is to be formed into a body with internal and/or external surfaces that approximate hyperboloids of one sheet is placed so that its axis is set at a predetermined skew angle with relation to a traveling EDM electrode wire. The electrode wire is then moved into cutting proximity of the body wire. Thereafter, by revolving the body about its own axis, the external and/or internal surfaces of the body will be cut into an approximate hyperbolic surface of revolution depending upon whether the body is positioned with the cutting wire outside of the body or in a previously formed longitudinal passage in the body. As an alternative technique, elongated channels can also be cut into the wall of the body by successively orienting the body to a selected number of angular positions, with the electrode wire being either outside of the body or in a previously formed passage in the body. At each of these angular positions, the electrode wire is moved orthogonally with respect to the axis of the wire, while both the body axis skew angle and the rotational position about that axis is controlled by cutting a channel or groove in the body to relieve stresses in the body material or to convey a coolant fluid.

  7. Nozzle fabrication technique

    NASA Technical Reports Server (NTRS)

    Wells, Dennis L. (Inventor)

    1989-01-01

    A block of electrically-conductive material which is to be formed into a body with internal and/or external surfaces that approximate hyperboloids of one sheet is placed so that its axis is set at a predetermined skew angle with relation to a travelling EDM electrode wire and the electrode wire is then moved into cutting proximity of the body. Thereafter, by revolving the body about its own axis, the external and/or internal surfaces of the body will be cut into an approximate hyperbolic surface of revolution depending upon whether the body is positioned with the cutting wire outside of the body or in a previously-formed longitudinal passage in the body. As an alternative technique, elongated channels can also be cut into the walls of the body by successively orienting the body to a selected number of angular positions with the electrode wire being either outside of the body or in a previously-formed passage in the body. At each of these angular positions, the electrode wire is moved orthogonally with respect to the axis of the wire while both the body axis skew angle and the rotational position about that axis are controlled for cutting a channel or groove in the body as required to relieve stresses in the material of the body or to convey a coolant fluid.

  8. Improved Search Techniques

    NASA Technical Reports Server (NTRS)

    Albornoz, Caleb Ronald

    2012-01-01

    Thousands of millions of documents are stored and updated daily in the World Wide Web. Most of the information is not efficiently organized to build knowledge from the stored data. Nowadays, search engines are mainly used by users who rely on their skills to look for the information needed. This paper presents different techniques search engine users can apply in Google Search to improve the relevancy of search results. According to the Pew Research Center, the average person spends eight hours a month searching for the right information. For instance, a company that employs 1000 employees wastes $2.5 million dollars on looking for nonexistent and/or not found information. The cost is very high because decisions are made based on the information that is readily available to use. Whenever the information necessary to formulate an argument is not available or found, poor decisions may be made and mistakes will be more likely to occur. Also, the survey indicates that only 56% of Google users feel confident with their current search skills. Moreover, just 76% of the information that is available on the Internet is accurate.

  9. Programing techniques for CDC equipment

    NASA Technical Reports Server (NTRS)

    Newsom, J. R.; Tiffany, S. H.

    1979-01-01

    Five techniques reduce core requirements for fast batch turnaround time and interactive-terminal capability. Same techniques increase program versatility, decrease problem-configuration dependence, and facilitate interprogram communication.

  10. Technique Selectively Represses Immune System

    MedlinePlus

    ... Research Matters December 3, 2012 Technique Selectively Represses Immune System Myelin (green) encases and protects nerve fibers (brown). A new technique prevents the immune system from attacking myelin in a mouse model of ...

  11. Advanced techniques of laser telemetry

    NASA Astrophysics Data System (ADS)

    Donati, S.; Gilardini, A.

    The relationships which govern a laser telemeter; noise sources; and measurement accuracy with pulsed and sinusoidal intensity modulation techniques are discussed. Developments in telemetry instrumention and optical detection are considered. Meteorological interferometers, geodimeters, and military telemeters are described. Propagation attenuation and signal to noise ratios are treated. It is shown that accuracy depends on the product of measurement time and received power. The frequency scanning technique of CW and long pulse telemetry; multifrequency techniques; pulse compression; and vernier technique are outlined.

  12. Cobbler's Technique for Iridodialysis Repair.

    PubMed

    Pandav, Surinder Singh; Gupta, Parul Chawla; Singh, Rishi Raj; Das, Kalpita; Kaushik, Sushmita; Raj, Srishti; Ram, Jagat

    2016-01-01

    We describe a novel "Cobbler's technique" for iridodialysis repair in the right eye of a patient aged 18 years, with a traumatic iridodialysis secondary to open globe injury with an iron rod. Our technique is simple with easy surgical maneuvers, that is, effective for repairing iridodialysis. The "Cobbler's technique" allows a maximally functional and cosmetic result for iridodialysis. PMID:26957855

  13. Ethical Use of Gestalt Techniques.

    ERIC Educational Resources Information Center

    Given, Jane A.

    The purpose of this paper is to engender a healthy respect for Gestalt theory and techniques and the use of the techniques in the client's best interest and in the interest of positive professional and self-development in the practitioner. An overview of Gestalt techniques is provided, concentrating on the two category divisions of experiments and…

  14. Dramatic Techniques in ESL Instruction.

    ERIC Educational Resources Information Center

    Radin, Barbara

    Three techniques have been found to be helpful in using dramatic techniques to provide motivation, self-confidence, and self-esteem to students of English as a second language at Hostos Community College. Strategic interaction is a technique based on the open-ended scenario, in which students are free to respond to the problem presented in the…

  15. Dose Reduction Techniques

    SciTech Connect

    WAGGONER, L.O.

    2000-05-16

    As radiation safety specialists, one of the things we are required to do is evaluate tools, equipment, materials and work practices and decide whether the use of these products or work practices will reduce radiation dose or risk to the environment. There is a tendency for many workers that work with radioactive material to accomplish radiological work the same way they have always done it rather than look for new technology or change their work practices. New technology is being developed all the time that can make radiological work easier and result in less radiation dose to the worker or reduce the possibility that contamination will be spread to the environment. As we discuss the various tools and techniques that reduce radiation dose, keep in mind that the radiological controls should be reasonable. We can not always get the dose to zero, so we must try to accomplish the work efficiently and cost-effectively. There are times we may have to accept there is only so much you can do. The goal is to do the smart things that protect the worker but do not hinder him while the task is being accomplished. In addition, we should not demand that large amounts of money be spent for equipment that has marginal value in order to save a few millirem. We have broken the handout into sections that should simplify the presentation. Time, distance, shielding, and source reduction are methods used to reduce dose and are covered in Part I on work execution. We then look at operational considerations, radiological design parameters, and discuss the characteristics of personnel who deal with ALARA. This handout should give you an overview of what it takes to have an effective dose reduction program.

  16. Techniques in Broadband Interferometry

    SciTech Connect

    Erskine, D J

    2004-01-04

    This is a compilation of my patents issued from 1997 to 2002, generally describing interferometer techniques that modify the coherence properties of broad-bandwidth light and other waves, with applications to Doppler velocimetry, range finding, imaging and spectroscopy. Patents are tedious to read in their original form. In an effort to improve their readability I have embedded the Figures throughout the manuscript, put the Figure captions underneath the Figures, and added section headings. Otherwise I have resisted the temptation to modify the words, though I found many places which could use healthy editing. There may be minor differences with the official versions issued by the US Patent and Trademark Office, particularly in the claims sections. In my shock physics work I measured the velocities of targets impacted by flyer plates by illuminating them with laser light and analyzing the reflected light with an interferometer. Small wavelength changes caused by the target motion (Doppler effect) were converted into fringe shifts by the interferometer. Lasers having long coherence lengths were required for the illumination. While lasers are certainly bright sources, and their collimated beams are convenient to work with, they are expensive. Particularly if one needs to illuminate a wide surface area, then large amounts of power are needed. Orders of magnitude more power per dollar can be obtained from a simple flashlamp, or for that matter, a 50 cent light bulb. Yet these inexpensive sources cannot practically be used for Doppler velocimetry because their coherence length is extremely short, i.e. their bandwidth is much too wide. Hence the motivation for patents 1 & 2 is a method (White Light Velocimetry) for allowing use of these powerful but incoherent lamps for interferometry. The coherence of the illumination is modified by passing it through a preparatory interferometer.

  17. Advanced qualification techniques

    SciTech Connect

    Winokur, P.S; Shaneyfelt, M.R.; Meisenheimer, T.L.; Fleetwood, D.M.

    1993-12-01

    This paper demonstrates use of the Qualified Manufacturers List (QML) methodology to qualify commercial and military microelectronics for use in space applications. QML ``builds in`` the hardness of product through statistical process control (SPC) of technology parameters relevant to the radiation response, test structure to integrated circuit (IC) correlations, and techniques for extrapolating laboratory test results to low-dose-rate space scenarios. Each of these elements is demonstrated and shown to be a cost-effective alternative to expensive end-of-line IC testing. Several examples of test structured-IC correlations are provided and recent work on complications arising from transistor scaling and geometry is discussed. The use of a 10-keV x-ray wafer-level test system to support SPC and establish ``process capability`` is illustrated and a comparison of 10-keV x-ray and Co{sup 60} gamma irradiations is provided for a wide range of CMOS technologies. The x-ray tester is shown to be cost-effective and its use in lot acceptance/qualification is recommended. Finally, a comparison is provided between MIL-STD-883D, Test Method 1019.4, which governs the testing of packaged semiconductor microcircuits in the DoD, and ESA/SSC Basic Specification No. 22900, Europe`s Total Dose Steady-State Irradiation Test Method. Test Method 1019.4 focuses on conservative estimates of MOS hardness for space and tactical applications, while Basic Specification 22900 focuses on improved simulation of low-dose-rate space environments.

  18. [Laparoscopic rectal resection technique].

    PubMed

    Anthuber, M; Kriening, B; Schrempf, M; Geißler, B; Märkl, B; Rüth, S

    2016-07-01

    The quality of radical oncological operations for patients with rectal cancer determines the rate of local recurrence and long-term survival. Neoadjuvant chemoradiotherapy for locally advanced tumors, a standardized surgical procedure for rectal tumors less than 12 cm from the anus with total mesorectal excision (TME) and preservation of the autonomous nerve system for sexual and bladder function have significantly improved the oncological results and quality of life of patients. The TME procedure for rectal resection has been performed laparoscopically in Germany for almost 20 years; however, no reliable data are available on the frequency of laparoscopic procedures in rectal cancer patients in Germany. The rate of minimally invasive procedures is estimated to be less than 20 %. A prerequisite for using the laparoscopic approach is implicit adherence to the described standards of open surgery. Available data from prospective randomized trials, systematic reviews and meta-analyses indicate that in the early postoperative phase the generally well-known positive effects of the minimally invasive approach to the benefit of patients can be realized without any long-term negative impact on the oncological results; however, the results of many of these studies are difficult to interpret because it could not be confirmed whether the hospitals and surgeons involved had successfully completed the learning curve. In this article we would like to present our technique, which we have developed over the past 17 years in more than 1000 patients. Based on our experiences the laparoscopic approach can be highly recommended as a suitable alternative to the open procedure. PMID:27277556

  19. Advanced qualification techniques

    NASA Astrophysics Data System (ADS)

    Winokur, P. S.; Shaneyfelt, M. R.; Meisenheimer, T. L.; Fleetwood, D. M.

    This paper demonstrates use of the Qualified Manufacturers List (QML) methodology to qualify commercial and military microelectronics for use in space applications. QML 'builds in' the hardness of product through statistical process control (SPC) of technology parameters relevant to the radiation response, test structure to integrated circuit (IC) correlations, and techniques for extrapolating laboratory test results to low-dose-rate space scenarios. Each of these elements is demonstrated and shown to be a cost-effective alternative to expensive end-of-line IC testing. Several examples of test structured-IC correlations are provided and recent work on complications arising from transistor scaling and geometry is discussed. The use of a 10-keV x-ray wafer-level test system to support SPC and establish 'process capability' is illustrated and a comparison of 10-keV x-ray and Co-60 gamma irradiations is provided for a wide range of CMOS technologies. The x-ray tester is shown to be cost-effective and its use in lot acceptance/qualification is recommended. Finally, a comparison is provided between MIL-STD-883D, Test Method 1019.4, which governs the testing of packaged semiconductor microcircuits in the DoD, and ESA/SSC Basic Specification No. 22900, Europe's Total Dose Steady-State Irradiation Test Method. Test Method 1019.4 focuses on conservative estimates of MOS hardness for space and tactical applications, while Basic Specification 22900 focuses on improved simulation of low-dose-rate space environments.

  20. Advanced qualification techniques

    SciTech Connect

    Winokur, P.S.; Shaneyfelt, M.R.; Meisenheimer, T.L.; Fleetwood, D.M. )

    1994-06-01

    This paper demonstrates use of the Qualified Manufacturers List (QML) methodology to qualify commercial and military microelectronics for use in space applications. QML ''builds in'' the hardness of product through statistical process control (SPC) of technology parameters relevant to the radiation response, test structure to integrated circuit (IC) correlations, and techniques for extrapolating laboratory test results to low-dose-rate space scenarios. Each of these elements is demonstrated and shown to be a cost-effective alternative to expensive end-of-line IC testing. Several examples of test structure-to-IC correlations are provided and recent work on complications arising from transistor scaling and geometry is discussed. The use of a 10-keV x-ray wafer-level test system to support SPC and establish ''process capability'' is illustrated and a comparison of 10-kev x-ray wafer-level test system to support SPC and establish ''process capability'' is illustrated and a comparison of 10-keV x-ray and Co[sup 60] gamma irradiations is provided for a wide range of CMOS technologies. The x-ray tester is shown to be cost-effective and its use in lot acceptance/qualification is recommended. Finally, a comparison is provided between MIL-STD-883, Test Method 1019.4, which governs the testing of packaged semiconductor microcircuits in the DoD, and ESA/SCC Basic Specification No. 22900, Europe's Total Dose Steady-State Irradiation Test Method. Test Method 1019.4 focuses on conservative estimates of MOS hardness for space and tactical applications, while Basic Specification 22900 focuses on improved simulation of low-dose-rate space environments.

  1. Advanced qualification techniques

    NASA Astrophysics Data System (ADS)

    Winokur, P. S.; Shaneyfelt, M. R.; Meisenheimer, T. L.; Fleetwood, D. M.

    1994-06-01

    This paper demonstrates use of the Qualified Manufacturers List (QML) methodology to qualify commercial and military microelectronics for use in space applications. QML 'builds in' the hardness of product through statistical process control (SPC) of technology parameters relevant to the radiation response, test structure to integrated circuit (IC) correlations, and techniques for extrapolating laboratory test results to low-dose-rate space scenarios. Each of these elements is demonstrated and shown to be a cost-effective alternative to expensive end-of-line IC testing. Several examples of test structure-to-IC correlations are provided and recent work on complications arising from transistor scaling and geometry is discussed. The use of a 10-keV x-ray wafer-level test system to support SPC and establish 'process capability' is illustrated and a comparison of 10-keV x-ray and Co-60 gamma irradiations is provided for a wide range of CMOS technologies. The x-ray tester is shown to be cost-effective and its use in lot acceptance/qualification is recommended. Finally, a comparison is provided between MIL-STD-883, Test Method 1019.4, which governs the testing of packaged semiconductor microcircuits in the DoD, and ESA/SCC Basic Specification No. 22900, Europe's Total Dose Steady-State Irradiation Test Method. Test Method 1019.4 focuses on conservative estimates of MOS hardness for space and tactical applications, while Basic Specification 22900 focuses on improved simulation of low-dose-rate space environments.

  2. Fog dispersion. [charged particle technique

    NASA Technical Reports Server (NTRS)

    Christensen, L. S.; Frost, W.

    1980-01-01

    The concept of using the charged particle technique to disperse warm fog at airports is investigated and compared with other techniques. The charged particle technique shows potential for warm fog dispersal, but experimental verification of several significant parameters, such as particle mobility and charge density, is needed. Seeding and helicopter downwash techniques are also effective for warm fog disperals, but presently are not believed to be viable techniques for routine airport operations. Thermal systems are currently used at a few overseas airports; however, they are expensive and pose potential environmental problems.

  3. [Dissection techniques in liver surgery].

    PubMed

    Rau, H G; Schauer, R; Pickelmann, S; Beyer, B C; Angele, M K; Zimmermann, A; Meimarakis, G; Heizmann, O; Schildberg, F W

    2001-02-01

    The first liver resection was performed in 1888. Since then a wide variety of dissection techniques have been introduced. The blunt dissection was replaced by novel methods, i.e. the CUSA technique and the Jet Cutter for major liver resections. These methods represent selective dissection techniques; whereas non-selective methods include the scalpel, scissors, linear stapling cutter, high-frequency coagulation, and the laser technique. The aim of this review article is the comparison of the different resection techniques in liver surgery, focussing on blood loss and resection time. PMID:11253668

  4. An improved technique for studying pleural fluid pressure and composition in rabbits.

    PubMed

    Del Fabbro, M

    1998-07-01

    Knowledge of pleural liquid pressure (Pliq) and composition is crucial for studies concerning intrapleural fluid dynamics, and pleural fluid turnover. We measured Pliq at intercostal and costal levels in anaesthetized spontaneously breathing rabbits using a minimally invasive method that assures a long-lasting hydraulic continuity between the pleural liquid and the recording system. Polyethylene tubes were glued either to the exposed endothoracic fascia or inserted into a rib to provide a scaled connection to the recording system. After inducing a pneumothorax with nitrous oxide (N2O) via an intrapleural cannula, a hole (approximately 0.7 mm2) was pierced in the parietal pleura through the tube lumen. The tubes were then connected to pressure transducers and the whole system was filled with heparinized saline to the level of the parietal pleura; finally the pneumo-thorax was removed after N2O washout and Pliq recordings were performed. A different kind of tube was used to obtain microsamples of pleural fluid (2.5-3 microliters) during spontaneous breathing; colloid osmotic pressure of the microsamples (pi liq) was measured with an osmometer, and averaged 9.3 +/- 1.5 cm H2o (n = 70 samples). When pooled and plotted against lung height end-expiratory intercostal and costal Pliq data scattered along a single regression line with a slope of -0.83 and -0.90 cm H2O cm(-1) in supine and prone animals, respectively. End-inspiratory costal Pliq was significantly more subatmospheric than intercostal in the ventral region of the chest (P < 0.05), and less subatmospheric in the dorsal region, regardless of posture. The techniques presented here could be helpful in gaining a greater insight into the physiology and pathophysiology of the pleural space in terms of pleural fluid dynamics and turnover.

  5. PDV Probe Alignment Technique

    SciTech Connect

    Whitworth, T L; May, C M; Strand, O T

    2007-10-26

    This alignment technique was developed while performing heterodyne velocimetry measurements at LLNL. There are a few minor items needed, such as a white card with aperture in center, visible alignment laser, IR back reflection meter, and a microscope to view the bridge surface. The work was performed on KCP flyers that were 6 and 8 mils wide. The probes used were Oz Optics manufactured with focal distances of 42mm and 26mm. Both probes provide a spot size of approximately 80?m at 1550nm. The 42mm probes were specified to provide an internal back reflection of -35 to -40dB, and the probe back reflections were measured to be -37dB and -33dB. The 26mm probes were specified as -30dB and both measured -30.5dB. The probe is initially aligned normal to the flyer/bridge surface. This provides a very high return signal, up to -2dB, due to the bridge reflectivity. A white card with a hole in the center as an aperture can be used to check the reflected beam position relative to the probe and launch beam, and the alignment laser spot centered on the bridge, see Figure 1 and Figure 2. The IR back reflection meter is used to measure the dB return from the probe and surface, and a white card or similar object is inserted between the probe and surface to block surface reflection. It may take several iterations between the visible alignment laser and the IR back reflection meter to complete this alignment procedure. Once aligned normal to the surface, the probe should be tilted to position the visible alignment beam as shown in Figure 3, and the flyer should be translated in the X and Y axis to reposition the alignment beam onto the flyer as shown in Figure 4. This tilting of the probe minimizes the amount of light from the bridge reflection into the fiber within the probe while maintaining the alignment as near normal to the flyer surface as possible. When the back reflection is measured after the tilt adjustment, the level should be about -3dB to -6dB higher than the probes

  6. Aseptic technique in microgravity.

    PubMed

    McCuaig, K

    1992-11-01

    Within the next decade, the United States will launch a space station into low Earth orbit as a preliminary step toward a manned mission to Mars. Provision of asepsis in the unique microgravity environment, essential in operative and invasive procedures, is addressed. An assessment of conventional terrestrial aseptic methods and possible modifications for a microgravity environment was done during the microgravity portion of parabolic flight on NASA KC-135 aircraft. During 110 parabolas on three flight days, a "surgical team" (surgeon, scrub nurse and circulating nurse) using a life size mannequin fastened to a prototype surgical "work station" (operating table), evaluated open and closed gloving (ten parabolas), skin preparation (six parabolas), surgical scrub methods (24 parabolas), gowning (22 parabolas) and draping (48 parabolas). Evaluated were povidone iodine solution, 1 percent povidone iodine detergent, Chloroxylenol with detergent, wet prep soap sponge, a water insoluble iodophor polymer (DuraPrep, 3M), disposable towels, disposable and reusable gowns, large and small disposable drapes with and without adhesive edges, disposable latex surgeon's gloves with and without packaging modifications and restraint mechanisms (tether, swiss seat, waist and foot restraint devices, fairfield and wire clamps and clips). Ease of use, provision of restraint for supplies and personnel and waste disposal were assessed. The literature was reviewed and its relevance to the space environment discussed, including risk factors, environmental contamination, immune status and microbiology. The microgravity environment, limited water supply and restricted operating area mandated that modifications of fabrication and packaging of supplies and technique be made to create and preserve asepsis. Material must meet stringent flammability and off-gassing standards. Either a chlorhexidine or povidone iodine detergent prepackaged brush and sponge would provide an adequate scrub plus

  7. Ultra high speed image processing techniques. [electronic packaging techniques

    NASA Technical Reports Server (NTRS)

    Anthony, T.; Hoeschele, D. F.; Connery, R.; Ehland, J.; Billings, J.

    1981-01-01

    Packaging techniques for ultra high speed image processing were developed. These techniques involve the development of a signal feedthrough technique through LSI/VLSI sapphire substrates. This allows the stacking of LSI/VLSI circuit substrates in a 3 dimensional package with greatly reduced length of interconnecting lines between the LSI/VLSI circuits. The reduced parasitic capacitances results in higher LSI/VLSI computational speeds at significantly reduced power consumption levels.

  8. A simplified technique of performing splenorenal shunt (Omar's technique).

    PubMed

    Shah, Omar Javed; Robbani, Irfan

    2005-01-01

    The splenorenal shunt procedure introduced by Robert Linton in 1947 is still used today in those regions of the world where portal hypertension is a common problem. However, because most surgeons find Linton's shunt procedure technically difficult, we felt that a simpler technique was needed. We present the surgical details and results of 20 splenorenal anastomosis procedures performed within a period of 30 months. Half of the patients (Group I) underwent Linton's conventional technique of splenorenal shunt; the other half (Group II) underwent a newly devised, simplified shunt technique. This new technique involves dissection of the fusion fascia of Toldt. The outcome of the 2 techniques was identical with respect to the reduction of preshunt portal pressure. However, our simplified technique was advantageous in that it significantly reduced the duration of surgery (P <0.001) and the amount of intraoperative blood loss (P <0.003). No patient died after either operation. Although Linton's splenorenal shunt is difficult and technically demanding, it is still routinely performed. The new technique described here, in addition to being simpler, helps achieve good vascular control, permits easier dissection of the splenic vein, enables an ideal anastomosis, decreases intraoperative blood loss, and reduces the duration of surgery. Therefore, we recommend the routine use of this simplified technique (Omar's technique) for the surgical treatment of portal hypertension. PMID:16429901

  9. Classroom Assessment Techniques

    NASA Astrophysics Data System (ADS)

    Narayanan, M.

    2003-12-01

    and the learner should be carefully observed and monitored. Forrest says that Student Portfolios, which document learning in more detail, seldom reveal how teaching contributes to students' progress. Cerbin further indicates that a course portfolio is essentially, a like a manuscript of scholarly work in progress. In this example, it is a work that explains what, how, and why students learn or do not learn in a course. In this paper, the author reports on a dozen techniques that could perhaps be used to document assessment of student learning. References : Cerbin, W. (1993). Fostering a culture of teaching as scholarship. The Teaching Professor, 7(3), 1-2. Edgerton, R., Hutchings, P., & Quinlan, P. (1991). The teaching portfolio: Capturing the scholarship in teaching. Washington, DC: American Association for Higher Education. Forrest, A. (1990). Time will tell: Portfolio-assisted assessment of general education. Washington, DC: American Association for Higher Education. Linn, R., Baker, E., & Dunbar, S. (1991). Complex, Performance-based Assessment: Expectations and Validation Criteria. Educational Researcher, 20 (8), 15-21. Narayanan, M. (2003). Assessment in Higher Education: Partnerships in Learning. Paper presented at the 23rd Annual Lilly Conference on College Teaching, Miami University, Oxford, OH. Seldin, P. (1991). The teaching portfolio. Bolton, MA: Anker. Young, C. O., Sr., & Young, L. H. (1999). Assessing Learning in Interactive Courses. Journal on Excellence in College Teaching, 10 (1), 63-76.

  10. Effects of cardiac oscillations and lung volume on acinar gas mixing during apnea

    SciTech Connect

    Mackenzie, C.F.; Skacel, M.; Barnas, G.M.; Brampton, W.J.; Alana, C.A. )

    1990-05-01

    We evaluated the importance of cardiogenic gas mixing in the acini of 13 dogs during 2 min of apnea. 133Xe (1-2 mCi in 4 ml of saline) was injected into an alveolar region through an occluded pulmonary artery branch, and washout was measured by gamma scintillation scanning during continued occlusion or with blood flow reinstated. The monoexponential rate constant for Xe washout (XeW) was -0.4 +/- 0.08 (SE) min-1 at functional residual capacity (FRC) with no blood flow in the injected region. It decreased by more than half at lung volumes 500 ml above and 392 ml below FRC. With intact pulmonary blood flow, XeW was -1.0 +/- 0.08 (SE) min-1 at FRC, and it increased with decreasing lung volume. However, if calculated Xe uptake by the blood was subtracted from the XeW measured with blood flow intact, resulting values at FRC and at FRC + 500 ml were not different from XeW with no blood flow. Reasonable calculation of Xe blood uptake at 392 ml below FRC was not possible because airway closure, increased shunt, and other factors affect XeW. After death, no significant XeW could be measured, which suggests that XeW caused by molecular diffusion was small. We conclude that (1) the effect of heart motion on the lung parenchyma increases acinar gas mixing during apnea, (2) this effect diminishes above or below FRC, and (3) there is probably no direct effect of pulmonary vascular pulsatility on acinar gas mixing.

  11. Field techniques for sampling ants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ants occur in most environments and ecologists ask a diverse array of questions involving ants. Thus, a key consideration in ant studies is to match the environment and question (and associated environmental variables) to the ant sampling technique. Since each technique has distinct limitations, usi...

  12. Resiliency Techniques in School Practice

    ERIC Educational Resources Information Center

    Molony, Terry; Henwood, Maureen; Gilroy, Shawn

    2010-01-01

    School psychologists can help build resilience in youth in many ways. This article offers a list of some easy techniques to use when working with individuals or groups, most based on basic cognitive-behavior therapy (CBT) techniques. They include: (1) Emotional awareness; (2) Emotional Regulation; (3) Cognitive Flexibility; (4) Self-efficacy; and…

  13. Passage Retrieval: A Probabilistic Technique.

    ERIC Educational Resources Information Center

    Melucci, Massimo

    1998-01-01

    Presents a probabilistic technique to retrieve passages from texts having a large size or heterogeneous semantic content. Results of experiments comparing the probabilistic technique to one based on a text segmentation algorithm revealed that the passage size affects passage retrieval performance; text organization and query generality may have an…

  14. Numerical grid generation techniques. [conference

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The state of the art in topology and flow geometry is presented. Solution techniques for partial differential equations are reviewed and included developments in coordinate transformations, conformal mapping, and invariant imbeddings. Applications of these techniques in fluid mechanics, flow geometry, boundary value problems, and fluidics are presented.

  15. TECHNIQUES FOR TEACHING CONSERVATION EDUCATION.

    ERIC Educational Resources Information Center

    BROWN, ROBERT E.; MOUSER, G.W.

    CONSERVATION PRINCIPLES, FIELD METHODS AND TECHNIQUES, AND SPECIFIC FIELD LEARNING ACTIVITIES ARE INCLUDED IN THIS REFERENCE VOLUME FOR TEACHERS. CONSERVATION PRINCIPLES INCLUDE STATEMENTS PERTAINING TO (1) SOIL, (2) WATER, (3) FOREST, AND (4) WILDLIFE. FIELD METHODS AND TECHNIQUES INCLUDE (1) PREPARING FOR A FIELD TRIP, (2) GETTING STUDENT…

  16. Comparing the effects of two Swedish massage techniques on the vital signs and anxiety of healthy women

    PubMed Central

    Gholami-Motlagh, Farzaneh; Jouzi, Mina; Soleymani, Bahram

    2016-01-01

    Background: Anxiety is an inseparable part of our lives and a serious threat to health. Therefore, it is necessary to use certain strategies to prevent disorders caused by anxiety and adjust the vital signs of people. Swedish massage is one of the most recognized techniques for reducing anxiety. This study aims to compare the effects of two massage techniques on the vital signs and anxiety of healthy women. Materials and Methods: This quasi-experimental study with a two-group, crossover design was conducted on 20 healthy women who were selected by simple sampling method and were randomly assigned to BNC (Back, Neck, and Chest) or LAF (Leg, Arm, and Face) groups. Massage therapy was carried out for a 14-week period (two 4-week massage therapy sessions and 6 weeks washout stage). Gathered data were analyzed using paired t-test with a significance level of P < 0.05. Results: Both BNC and LAF methods caused a significant decrease in systolic BP in the first stage (P = 0.02, 0.00); however, diastolic BP showed significant decrease only in BNC group (P = 0.01). The mean average of body temperature of LAF group showed a significant decrease in the first stage (P = 0.0.3), and pulse and respiratory rate showed significant decrease in both groups during the second stage (P = 0.00). In addition, anxiety scores showed no significant difference before and after massage therapy (P < 0.05). Conclusions: Massage therapy caused a decrease in systolic BP, pulse, and respiratory rate. It can be concluded that massage therapy was useful for decreasing the vital signs associated with anxiety in healthy women. PMID:27563325

  17. Single Cell Electrical Characterization Techniques.

    PubMed

    Mansor, Muhammad Asraf; Ahmad, Mohd Ridzuan

    2015-01-01

    Electrical properties of living cells have been proven to play significant roles in understanding of various biological activities including disease progression both at the cellular and molecular levels. Since two decades ago, many researchers have developed tools to analyze the cell's electrical states especially in single cell analysis (SCA). In depth analysis and more fully described activities of cell differentiation and cancer can only be accomplished with single cell analysis. This growing interest was supported by the emergence of various microfluidic techniques to fulfill high precisions screening, reduced equipment cost and low analysis time for characterization of the single cell's electrical properties, as compared to classical bulky technique. This paper presents a historical review of single cell electrical properties analysis development from classical techniques to recent advances in microfluidic techniques. Technical details of the different microfluidic techniques are highlighted, and the advantages and limitations of various microfluidic devices are discussed. PMID:26053399

  18. Photogrammetric techniques for aerospace applications

    NASA Astrophysics Data System (ADS)

    Liu, Tianshu; Burner, Alpheus W.; Jones, Thomas W.; Barrows, Danny A.

    2012-10-01

    Photogrammetric techniques have been used for measuring the important physical quantities in both ground and flight testing including aeroelastic deformation, attitude, position, shape and dynamics of objects such as wind tunnel models, flight vehicles, rotating blades and large space structures. The distinct advantage of photogrammetric measurement is that it is a non-contact, global measurement technique. Although the general principles of photogrammetry are well known particularly in topographic and aerial survey, photogrammetric techniques require special adaptation for aerospace applications. This review provides a comprehensive and systematic summary of photogrammetric techniques for aerospace applications based on diverse sources. It is useful mainly for aerospace engineers who want to use photogrammetric techniques, but it also gives a general introduction for photogrammetrists and computer vision scientists to new applications.

  19. Single Cell Electrical Characterization Techniques

    PubMed Central

    Mansor, Muhammad Asraf; Ahmad, Mohd Ridzuan

    2015-01-01

    Electrical properties of living cells have been proven to play significant roles in understanding of various biological activities including disease progression both at the cellular and molecular levels. Since two decades ago, many researchers have developed tools to analyze the cell’s electrical states especially in single cell analysis (SCA). In depth analysis and more fully described activities of cell differentiation and cancer can only be accomplished with single cell analysis. This growing interest was supported by the emergence of various microfluidic techniques to fulfill high precisions screening, reduced equipment cost and low analysis time for characterization of the single cell’s electrical properties, as compared to classical bulky technique. This paper presents a historical review of single cell electrical properties analysis development from classical techniques to recent advances in microfluidic techniques. Technical details of the different microfluidic techniques are highlighted, and the advantages and limitations of various microfluidic devices are discussed. PMID:26053399

  20. Presentation-Oriented Visualization Techniques.

    PubMed

    Kosara, Robert

    2016-01-01

    Data visualization research focuses on data exploration and analysis, yet the vast majority of visualizations people see were created for a different purpose: presentation. Whether we are talking about charts showing data to help make a presenter's point, data visuals created to accompany a news story, or the ubiquitous infographics, many more people consume charts than make them. Traditional visualization techniques treat presentation as an afterthought, but are there techniques uniquely suited to data presentation but not necessarily ideal for exploration and analysis? This article focuses on presentation-oriented techniques, considering their usefulness for presentation first and any other purposes as secondary.

  1. Videogrammetric Model Deformation Measurement Technique

    NASA Technical Reports Server (NTRS)

    Burner, A. W.; Liu, Tian-Shu

    2001-01-01

    The theory, methods, and applications of the videogrammetric model deformation (VMD) measurement technique used at NASA for wind tunnel testing are presented. The VMD technique, based on non-topographic photogrammetry, can determine static and dynamic aeroelastic deformation and attitude of a wind-tunnel model. Hardware of the system includes a video-rate CCD camera, a computer with an image acquisition frame grabber board, illumination lights, and retroreflective or painted targets on a wind tunnel model. Custom software includes routines for image acquisition, target-tracking/identification, target centroid calculation, camera calibration, and deformation calculations. Applications of the VMD technique at five large NASA wind tunnels are discussed.

  2. PIGE technique implementation at ININ

    SciTech Connect

    Policroniades, R. Martínez-Quiroz, E.; Méndez-Garrido, B.; Murillo, G.; Moreno, E.; Villaseñor, P.

    2015-07-23

    In this work, we present a general overview about the implementation at ININ of a Particle Induced Gamma Emission (PIGE) analysis technique, based on the bombardment of samples by protons and deuterons at different energies within our tandem accelerator facility. As it is well known, this technique is based on the detection of γ-rays emitted by nuclei in a target following a charged particle irradiation. The main feature of this technique, apart from being non-destructive and low time consuming, is that it allows a multi-elemental analysis of a sample, permitting an isotopic identification of many nuclides. Advances and some preliminary results are presented.

  3. New techniques on embryo manipulation.

    PubMed

    Escribá, M J; Valbuena, D; Remohí, J; Pellicer, A; Simón, C

    2002-01-01

    For many years, experience has been accumulated on embryo and gamete manipulation in livestock animals. The present work is a review of these techniques and their possible application in human embryology in specific cases. It is possible to manipulate gametes at different levels, producing paternal or maternal haploid embryos (hemicloning), using different techniques including nuclear transfer. At the embryonic stage, considering practical, ethical and legal issues, techniques will be reviewed that include cloning and embryo splitting at the cleavage stage, morula, or blastocyst stage.

  4. Light absorption measurements: new techniques.

    PubMed

    Hänel, G; Busen, R; Hillenbrand, C; Schloss, R

    1982-02-01

    A new radiometer is described which simplifies measurement of the radiation supply of solar wavelengths. Two methods of measuring the radiant energy absorbed by aerosol particles are described: A photometric technique is used for particles collected on filters, and a calorimetric technique is used for in situ measurements. Data collected with the radiometer and the light absorption techniques yield the heating rate of the atmosphere due to light absorption by the particles. Sample measurements show substantial atmospheric temperature increases due to absorption, especially in industrial regions.

  5. Multigrid techniques for unstructured meshes

    NASA Technical Reports Server (NTRS)

    Mavriplis, D. J.

    1995-01-01

    An overview of current multigrid techniques for unstructured meshes is given. The basic principles of the multigrid approach are first outlined. Application of these principles to unstructured mesh problems is then described, illustrating various different approaches, and giving examples of practical applications. Advanced multigrid topics, such as the use of algebraic multigrid methods, and the combination of multigrid techniques with adaptive meshing strategies are dealt with in subsequent sections. These represent current areas of research, and the unresolved issues are discussed. The presentation is organized in an educational manner, for readers familiar with computational fluid dynamics, wishing to learn more about current unstructured mesh techniques.

  6. Submucosal tunneling techniques: current perspectives

    PubMed Central

    Kobara, Hideki; Mori, Hirohito; Rafiq, Kazi; Fujihara, Shintaro; Nishiyama, Noriko; Ayaki, Maki; Yachida, Tatsuo; Matsunaga, Tae; Tani, Johji; Miyoshi, Hisaaki; Yoneyama, Hirohito; Morishita, Asahiro; Oryu, Makoto; Iwama, Hisakazu; Masaki, Tsutomu

    2014-01-01

    Advances in endoscopic submucosal dissection include a submucosal tunneling technique, involving the introduction of tunnels into the submucosa. These tunnels permit safer offset entry into the peritoneal cavity for natural orifice transluminal endoscopic surgery. Technical advantages include the visual identification of the layers of the gut, blood vessels, and subepithelial tumors. The creation of a mucosal flap that minimizes air and fluid leakage into the extraluminal cavity can enhance the safety and efficacy of surgery. This submucosal tunneling technique was adapted for esophageal myotomy, culminating in its application to patients with achalasia. This method, known as per oral endoscopic myotomy, has opened up the new discipline of submucosal endoscopic surgery. Other clinical applications of the submucosal tunneling technique include its use in the removal of gastrointestinal subepithelial tumors and endomicroscopy for the diagnosis of functional and motility disorders. This review suggests that the submucosal tunneling technique, involving a mucosal safety flap, can have potential values for future endoscopic developments. PMID:24741323

  7. Gender, Persuasion Techniques, and Collaboration.

    ERIC Educational Resources Information Center

    Raign, Kathryn Rosser; Sims, Brenda R.

    1993-01-01

    Examines preconceptions of four proposal developers about three factors: effective and ineffective collaboration; gender's effects on collaboration; and gender's effect on persuasion. Finds the discourse techniques used by men and women do not parallel a person's gender. (RS)

  8. Technique of transanal endoscopic microsurgery.

    PubMed

    Buess, G; Kipfmüller, K; Hack, D; Grüssner, R; Heintz, A; Junginger, T

    1988-01-01

    Sessile adenomas are predominantly localized in the rectum and lower sigma. Surgical removal is indicated but often implies an invasive surgical procedure. Using conventional transanal surgical techniques, only the lower rectum can be reached and there are high rates of recurrence. The new technique combines an endoscopic view of the rectum under gas insufflation via a stereoscopic telescope with conventional surgical preparation and suturing. Adenomas can be excised using the mucosectomy technique or full-thickness-excision, whereas carcinomas should be excised using full-thickness excision with a sufficient border of healthy mucosa. In carcinomas of the sacral cavity, we remove the retrorectal fat up to the fascia of Waldeyer, including the regional lymph nodes. Transanal endoscopic microsurgery is the most economical and tissue-saving surgical technique for the removal of rectal adenomas and early rectal carcinomas.

  9. Modern Observational Techniques for Comets

    NASA Technical Reports Server (NTRS)

    Brandt, J. C. (Editor); Greenberg, J. M. (Editor); Donn, B. (Editor); Rahe, J. (Editor)

    1981-01-01

    Techniques are discussed in the following areas: astrometry, photometry, infrared observations, radio observations, spectroscopy, imaging of coma and tail, image processing of observation. The determination of the chemical composition and physical structure of comets is highlighted.

  10. Supercooling Water: A Simple Technique.

    ERIC Educational Resources Information Center

    Geer, Ira W.

    1980-01-01

    Describes a technique for the supercooling of water, for use in the science classroom, involving adding common salt to a mixture of ice and water. Several investigations are included for use during (and after) the process of supercooling. (DS)

  11. Spectroscopic Techniques for Atmospheric Analysis

    SciTech Connect

    Bililign, Solomon

    2009-07-06

    Several analytical and optical techniques for atmospheric analysis are discussed. Environmental constraints for real world applications are mentioned. Special emphasis is given to the cavity ring Down Spectroscopy as a very sensitive method for atmospheric trace gas detection is described.

  12. Novel/experimental bariatric techniques.

    PubMed

    Thorell, Anders

    2014-01-01

    Due to the documented effects regarding durable and pronounced weight loss as well as improvement/resolution of obesity-associated morbidity, the number of bariatric surgical procedures performed has increased in an 'epidemiologic' fashion during the last decade. Most common/established procedures used today have well-documented effects but are all associated with technique-specific advantages as well as shortcomings. In particular, complications in the short as well as long term constitute a drive for continuous development of new techniques. A common feature of such new techniques is to reduce the degree of surgical trauma by being less invasive. Some of the new techniques used for bariatric treatment have been in clinical practice for a long time. However, due to the lack of controlled data with documentation of their efficacy and risk of complications, these are still to be considered as experimental. Other techniques are newly being introduced, and therefore data on their potential use for treatment of morbidly obese patients are limited. In this article, an overview of some of the most important of such new techniques is given. Some recently presented methodologies in which very sparse documentation is present, but which have been appreciated for being innovative and sometimes controversial, are also mentioned. PMID:24819498

  13. Genetic techniques for the archaea.

    PubMed

    Farkas, Joel A; Picking, Jonathan W; Santangelo, Thomas J

    2013-01-01

    Genetic techniques for the Archaea have undergone a rapid expansion in complexity, resulting in increased exploration of the role of Archaea in the environment and detailed analyses of the molecular physiology and information-processing systems in the third domain of life. Complementary gains in describing the ever-increasing diversity of archaeal organisms have allowed these techniques to be leveraged in new and imaginative ways to elucidate shared and unique aspects of archaeal diversity and metabolism. In this review, we introduce the four archaeal clades for which advanced genetic techniques are available--the methanogens, halophiles, Sulfolobales, and Thermococcales--with the aim of providing an overall profile of the advantages and disadvantages of working within each clade, as essentially all of the genetically accessible archaeal organisms require unique culturing techniques that present real challenges. We discuss the full repertoire of techniques possible within these clades while highlighting the recent advances that have been made by taking advantage of the most prominent techniques and approaches.

  14. Microscopy techniques in flavivirus research.

    PubMed

    Chong, Mun Keat; Chua, Anthony Jin Shun; Tan, Terence Tze Tong; Tan, Suat Hoon; Ng, Mah Lee

    2014-04-01

    The Flavivirus genus is composed of many medically important viruses that cause high morbidity and mortality, which include Dengue and West Nile viruses. Various molecular and biochemical techniques have been developed in the endeavour to study flaviviruses. However, microscopy techniques still have irreplaceable roles in the identification of novel virus pathogens and characterization of morphological changes in virus-infected cells. Fluorescence microscopy contributes greatly in understanding the fundamental viral protein localizations and virus-host protein interactions during infection. Electron microscopy remains the gold standard for visualizing ultra-structural features of virus particles and infected cells. New imaging techniques and combinatory applications are continuously being developed to push the limit of resolution and extract more quantitative data. Currently, correlative live cell imaging and high resolution three-dimensional imaging have already been achieved through the tandem use of optical and electron microscopy in analyzing biological specimens. Microscopy techniques are also used to measure protein binding affinities and determine the mobility pattern of proteins in cells. This chapter will consolidate on the applications of various well-established microscopy techniques in flavivirus research, and discuss how recently developed microscopy techniques can potentially help advance our understanding in these membrane viruses.

  15. Stapedotomy: the JB Causse technique.

    PubMed

    Causse, J B; Lopez, A; Juberthie, L; Olivier, J C

    1991-09-01

    The Jean-Bernard Causse technique of stapedotomy, derived from Jean René Causse "Teflon-interposition" technique, offers an optimum reconstitution of the function of the annular ligament of the stapes footplate. The quantity and quality of hearing depend significantly, among other things, on the function of the stapes footplate annular ligament. Its impedance keeps the perilymph motion within a physiological acoustic amplitude quantum level unless the movements are so excessive as in barotrauma and acoustic trauma which would have overworked even the annular ligament of a normal footplate. This surgical technique permits snorkling, scuba-diving, airplane landing, eustachian tube dysfunction after surgery as in a normal individual who did not undergo otosclerosis surgery. A comparative study on the postoperative hearing based on 3,000 out of 14,000 cases done by J C Bausse technique, 127 cases with small fenestra technique and 267 cases of complete platinectomy showed too large stapedotomy gives poor high tones and too small stapedotomy poor low tones. Five year follow-up on the hearing loss indicated that total platinoctomy has 1.7 times more alteration of 4 kHz frequency in comparison to the technique reconstituting the annular ligament. Yearly audiogram to check the evolution of cochlear otospongiosis may lead the surgeon to prescribe sodium fluoride if the mid-frequencies are deteriorating and vascular drugs if the high pitch frequencies are deteriorating.

  16. Source term estimation of radioxenon released from the Fukushima Dai-ichi nuclear reactors using measured air concentrations and atmospheric transport modeling.

    PubMed

    Eslinger, P W; Biegalski, S R; Bowyer, T W; Cooper, M W; Haas, D A; Hayes, J C; Hoffman, I; Korpach, E; Yi, J; Miley, H S; Rishel, J P; Ungar, K; White, B; Woods, V T

    2014-01-01

    Systems designed to monitor airborne radionuclides released from underground nuclear explosions detected radioactive fallout across the northern hemisphere resulting from the Fukushima Dai-ichi Nuclear Power Plant accident in March 2011. Sampling data from multiple International Modeling System locations are combined with atmospheric transport modeling to estimate the magnitude and time sequence of releases of (133)Xe. Modeled dilution factors at five different detection locations were combined with 57 atmospheric concentration measurements of (133)Xe taken from March 18 to March 23 to estimate the source term. This analysis suggests that 92% of the 1.24 × 10(19) Bq of (133)Xe present in the three operating reactors at the time of the earthquake was released to the atmosphere over a 3 d period. An uncertainty analysis bounds the release estimates to 54-129% of available (133)Xe inventory.

  17. Landing Techniques in Beach Volleyball

    PubMed Central

    Tilp, Markus; Rindler, Michael

    2013-01-01

    The aims of the present study were to establish a detailed and representative record of landing techniques (two-, left-, and right-footed landings) in professional beach volleyball and compare the data with those of indoor volleyball. Beach volleyball data was retrieved from videos taken at FIVB World Tour tournaments. Landing techniques were compared in the different beach and indoor volleyball skills serve, set, attack, and block with regard to sex, playing technique, and court position. Significant differences were observed between men and women in landings following block actions (χ2(2) = 18.19, p < 0.01) but not following serve, set, and attack actions. Following blocking, men landed more often on one foot than women. Further differences in landings following serve and attack with regard to playing technique and position were mainly observed in men. The comparison with landing techniques in indoor volleyball revealed overall differences both in men (χ2(2) = 161.4, p < 0.01) and women (χ2(2) = 84.91, p < 0.01). Beach volleyball players land more often on both feet than indoor volleyball players. Besides the softer surface in beach volleyball, and therefore resulting lower loads, these results might be another reason for fewer injuries and overuse conditions compared to indoor volleyball. Key Points About 1/3 of all jumping actions in beach volleyball result in a landing on one foot. Especially following block situations men land on one foot more often than women. Landing techniques are related to different techniques and positions. Landings on one foot are less common in beach volleyball than indoor volleyball. This could be a reason for fewer injuries and overuse conditions. PMID:24149150

  18. Landing techniques in beach volleyball.

    PubMed

    Tilp, Markus; Rindler, Michael

    2013-01-01

    The aims of the present study were to establish a detailed and representative record of landing techniques (two-, left-, and right-footed landings) in professional beach volleyball and compare the data with those of indoor volleyball. Beach volleyball data was retrieved from videos taken at FIVB World Tour tournaments. Landing techniques were compared in the different beach and indoor volleyball skills serve, set, attack, and block with regard to sex, playing technique, and court position. Significant differences were observed between men and women in landings following block actions (χ(2)(2) = 18.19, p < 0.01) but not following serve, set, and attack actions. Following blocking, men landed more often on one foot than women. Further differences in landings following serve and attack with regard to playing technique and position were mainly observed in men. The comparison with landing techniques in indoor volleyball revealed overall differences both in men (χ(2)(2) = 161.4, p < 0.01) and women (χ(2)(2) = 84.91, p < 0.01). Beach volleyball players land more often on both feet than indoor volleyball players. Besides the softer surface in beach volleyball, and therefore resulting lower loads, these results might be another reason for fewer injuries and overuse conditions compared to indoor volleyball. Key PointsAbout 1/3 of all jumping actions in beach volleyball result in a landing on one foot.Especially following block situations men land on one foot more often than women.Landing techniques are related to different techniques and positions.Landings on one foot are less common in beach volleyball than indoor volleyball. This could be a reason for fewer injuries and overuse conditions. PMID:24149150

  19. Applications of Electromigration Techniques: Electromigration Techniques in Detection of Microorganisms

    NASA Astrophysics Data System (ADS)

    Dziubakiewicz, Ewelina; Buszewski, Bogusław

    The detection and identification of microbes is a challenge and an important aspect in many fields of our lives from medicine to bioterrorism defense. However, the analysis of such complex molecules brings a lot of questions mainly about their behavior. Bacteria are biocolloid, whose surface charge originates from the ionization of carboxyl, phosphate, or amino groups and the adsorption of ions from solution. Consequently, the charged cell wall groups determine the spontaneous formation of the electrical double layer. In this chapter application of electromigration techniques for microorganism's identification and separation are described. This approach represents the possibility to apply electromigration techniques in medical diagnosis, detection of food contamination, and sterility testing.

  20. Review of uranium bioassay techniques

    SciTech Connect

    Bogard, J.S.

    1996-04-01

    A variety of analytical techniques is available for evaluating uranium in excreta and tissues at levels appropriate for occupational exposure control and evaluation. A few (fluorometry, kinetic phosphorescence analysis, {alpha}-particle spectrometry, neutron irradiation techniques, and inductively-coupled plasma mass spectrometry) have also been demonstrated as capable of determining uranium in these materials at levels comparable to those which occur naturally. Sample preparation requirements and isotopic sensitivities vary widely among these techniques and should be considered carefully when choosing a method. This report discusses analytical techniques used for evaluating uranium in biological matrices (primarily urine) and limits of detection reported in the literature. No cost comparison is attempted, although references are cited which address cost. Techniques discussed include: {alpha}-particle spectrometry; liquid scintillation spectrometry, fluorometry, phosphorometry, neutron activation analysis, fission-track counting, UV-visible absorption spectrophotometry, resonance ionization mass spectrometry, and inductively-coupled plasma mass spectrometry. A summary table of reported limits of detection and of the more important experimental conditions associated with these reported limits is also provided.

  1. Authentication techniques for smart cards

    SciTech Connect

    Nelson, R.A.

    1994-02-01

    Smart card systems are most cost efficient when implemented as a distributed system, which is a system without central host interaction or a local database of card numbers for verifying transaction approval. A distributed system, as such, presents special card and user authentication problems. Fortunately, smart cards offer processing capabilities that provide solutions to authentication problems, provided the system is designed with proper data integrity measures. Smart card systems maintain data integrity through a security design that controls data sources and limits data changes. A good security design is usually a result of a system analysis that provides a thorough understanding of the application needs. Once designers understand the application, they may specify authentication techniques that mitigate the risk of system compromise or failure. Current authentication techniques include cryptography, passwords, challenge/response protocols, and biometrics. The security design includes these techniques to help prevent counterfeit cards, unauthorized use, or information compromise. This paper discusses card authentication and user identity techniques that enhance security for microprocessor card systems. It also describes the analysis process used for determining proper authentication techniques for a system.

  2. Antigen retrieval techniques: current perspectives.

    PubMed

    Shi, S R; Cote, R J; Taylor, C R

    2001-08-01

    Development of the antigen retrieval (AR) technique, a simple method of boiling archival paraffin-embedded tissue sections in water to enhance the signal of immunohistochemistry (IHC), was the fruit of pioneering efforts guided by the philosophy of rendering IHC applicable to routine formalin-fixed, paraffin-embedded tissues for wide application of IHC in research and clinical pathology. On the basis of thousands of articles and many reviews, a book has recently been published that summarizes basic principles for practice and further development of the AR technique. Major topics with respect to several critical issues, such as the definition, application, technical principles, and further studies of the AR technique, are highlighted in this article. In particular, a further application of the heat-induced retrieval approach for sufficient extraction of nucleic acids in addition to proteins, and standardization of routine IHC based on the AR technique in terms of a test battery approach, are also addressed. Furthermore, understanding the mechanism of the AR technique may shed light on facilitating the development of molecular morphology.

  3. Single event upset hardening techniques

    SciTech Connect

    Weaver, H.T.; Corbett, W.T.

    1990-01-01

    Integrated circuit logic states are maintained by virtue of specific transistor combinations being either on'' (conducting) or off'' (nonconducting). High energy ion strikes on the microcircuit generate photocurrents whose primary detrimental effect is to make off'' transistors appear on,'' confusing the logic state and leading to single event upset (SEU). Protection against these soft errors is accomplished using either technology or circuit techniques, actions that generally impact yield and performance relative to unhardened circuits. We describe, and using circuit simulations analyze, a technique for hardening latches which requires combinations of technology and circuit modifications, but which provides SEU immunity without loss of speed. Specifically, a single logic state is hardened against SEU using technology methods and the information concerning valid states is then used to simplify hardened circuit design. The technique emphasizes some basic hardening concepts, ideas for which will be reviewed. 3 refs., 2 figs.

  4. Myelography: modern technique and indications.

    PubMed

    Pomerantz, Stuart R

    2016-01-01

    Myelography describes the instillation of intrathecal contrast media for the imaging evaluation of spinal canal pathology. The technique has evolved with the use of progressively less toxic contrast agents over its 90-year history and the inclusion of advanced image acquisition technology, including both computed tomography (CT) and magnetic resonance imaging (MRI), in addition to plain radiographic projections. The use of myelography for routine evaluation of spinal disease has diminished greatly due to the advent of MRI which has superior soft-tissue contrast and is relatively non-invasive. However, it is still a critical technique for conventional indications, such as spinal stenosis, when MRI is contraindicated or nondiagnostic. It is also recognized as the study of choice for brachial plexus injury, radiation therapy treatment planning, and cerebrospinal fluid (CSF) leak. Modern myelographic procedural technique and a discussion of how it contributes to these current indications will be reviewed in this chapter. PMID:27432666

  5. Evaluation of standard watermarking techniques

    NASA Astrophysics Data System (ADS)

    Marini, Enrico; Autrusseau, Florent; Le Callet, Patrick; Campisi, Patrizio

    2007-02-01

    In the last decade digital watermarking techniques have been devised to answer the ever-growing need to protect the intellectual property of digital still images, video sequences or audio from piracy attacks. Because of the proliferation of watermarking algorithms and their applications some benchmarks have been created in order to help watermarkers comparing their algorithms in terms of robustness against various attacks (i.e. Stirmark, Checkmark). However, no equal attention has been devoted to the proposition of benchmarks tailored to assess the watermark perceptual transparency. In this work, we study several watermarking techniques in terms of the mark invisibility through subjective experiments. Moreover, we test the ability of several objective metrics, used in the literature mainly to evaluate distortions due to the coding process, to be correlated with subjective scores. The conclusions drawn in the paper are supported by extensive experimentations using both several watermarking techniques and objective metrics.

  6. History of the Buttonhole Technique.

    PubMed

    Misra, Madhukar

    2015-01-01

    The constant side method of access cannulation in hemodialysis, popularly known as the 'buttonhole' method, has an interesting history. Dr. Zbylut J. Twardowski, a Polish nephrologist, discovered this technique by pure serendipity in 1972. A patient with a complicated vascular access history and limited options for cannulation was repeatedly 'stuck' at the same sites by a nurse. Soon it was noticed that the cannulation at the same spot became easier with time. Since the needles were being reused, the sharpness of the needles decreased with time and the bluntness of the needle seemed to minimize the damage to the cannulation tract (another serendipity!). This method soon became popular among patients, and many patients started using this technique. This chapter traces the invention of this technique and its subsequent development following Dr. Twardowski's emigration to the USA. PMID:26283554

  7. NASA standard: Trend analysis techniques

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Descriptive and analytical techniques for NASA trend analysis applications are presented in this standard. Trend analysis is applicable in all organizational elements of NASA connected with, or supporting, developmental/operational programs. This document should be consulted for any data analysis activity requiring the identification or interpretation of trends. Trend analysis is neither a precise term nor a circumscribed methodology: it generally connotes quantitative analysis of time-series data. For NASA activities, the appropriate and applicable techniques include descriptive and graphical statistics, and the fitting or modeling of data by linear, quadratic, and exponential models. Usually, but not always, the data is time-series in nature. Concepts such as autocorrelation and techniques such as Box-Jenkins time-series analysis would only rarely apply and are not included in this document. The basic ideas needed for qualitative and quantitative assessment of trends along with relevant examples are presented.

  8. Diversity imaging techniques in lidar

    NASA Technical Reports Server (NTRS)

    Schultz, K. I.

    1992-01-01

    Diversity imaging techniques have been successfully employed in conventional microwave range-Doppler imaging radars to obtain high resolution images of both natural and man-made targets. These techniques allow microwave radars to achieve image resolution which would otherwise require excessively large antennas. Recent advances in coherent laser radar techniques and signal processing have led to the development of range-Doppler imaging laser radars. While much of the theory and signal processing techniques used in microwave radars can be brought to bear on laser radars, the significant difference in wavelength results in issues peculiar to laser radar systems. Both the fundamental concepts and specific applications of diversity imaging techniques applied to laser radar imaging systems will be discussed. Angle, frequency, and bistatic angle degrees of freedom can be employed in a coherent laser radar imaging system to achieve image resolution which exceeds the traditional Rayleigh criterion associated with the receive aperture. In diversity imaging, angle and frequency degrees of freedom can be used to synthesize an effective aperture providing range and Doppler target information. The ability to vary the bistatic angle provides an additional means of synthesizing an effective aperture. Both simulated and experimentally obtained laser radar images of spinning and/or tumbling objects utilizing both angular and frequency diversity will be presented. In coherent laser radar systems, image quality can be dominated by laser speckle effects. In particular, the signal-to-noise ratio (SNR) of a coherent laser radar image is at most unity in the presence of fully developed speckle. Diversity techniques can be utilized to improve the image SNR; simple incoherent averaging of images utilizing temporal and polarization degrees of freedom can significantly improve image SNR. Both the SNR and image resolution (as defined by the synthetic aperture) contribute to image quality. The

  9. Lead extraction. Indications and techniques.

    PubMed

    Byrd, C L; Schwartz, S J; Hedin, N

    1992-11-01

    Each of the extraction techniques and their ancillary tools was reported as used successfully; however, until now, no technique has been successful when used in more than a few isolated instances. The technique for intravascular countertraction and the associated tools described in this paper were devised and selected in an attempt to develop one technique to be used on all patients, with all types of leads, and with a very low complication rate. Its versatility permitted single or multiple lead extractions combined with the precision of selecting and extracting a specific lead. In our experience, as well as the experience of others, the techniques described in this paper have proved to be superior by minimizing the inherent risk and morbidity, allowing us to expand the indications for lead removal beyond septicemia and free-floating leads, to include infection, abandonment of pockets, and replacement of malfunctioning or fractured leads. Intravascular countertraction was a consistently safe and efficacious method of removing transvenous pacemaker leads regardless of the duration of the implant, thus permitting extractions in patients not considered candidates for a more extensive surgical procedure. Intravascular countertraction encompasses surgical and fluoroscopic techniques possessed by most physicians experienced in pacemaker and automatic implantable cardioverter defibrillator implants. However, there is a learning curve, predicating caution for the inexperienced physician. In addition, advanced surgical skills may be needed in handling associated conditions such as debridement and primary closure of chronically inflamed tissues, especially in submuscular pockets and sinus tracts in the neck. Although the potential for a cardiovascular complication is small, it does exist, and cardiovascular surgical backup is a recommended precaution.

  10. Techniques in Endovascular Aneurysm Repair

    PubMed Central

    Phade, Sachin V.; Garcia-Toca, Manuel; Kibbe, Melina R.

    2011-01-01

    Endovascular repair of infrarenal abdominal aortic aneurysms (EVARs) has revolutionized the treatment of aortic aneurysms, with over half of elective abdominal aortic aneurysm repairs performed endoluminally each year. Since the first endografts were placed two decades ago, many changes have been made in graft design, operative technique, and management of complications. This paper summarizes modern endovascular grafts, considerations in preoperative planning, and EVAR techniques. Specific areas that are addressed include endograft selection, arterial access, sheath delivery, aortic branch management, graft deployment, intravascular ultrasonography, pressure sensors, management of endoleaks and compressed limbs, and exit strategies. PMID:22121487

  11. Drilling techniques for osteochondritis dissecans.

    PubMed

    Heyworth, Benton E; Edmonds, Eric W; Murnaghan, M Lucas; Kocher, Mininder S

    2014-04-01

    Although the advanced stages of osteochondritis dissecans remain challenging to treat, most early-stage lesions in skeletally immature patients, if managed appropriately, can be stimulated to heal. For stable lesions that do not demonstrate adequate healing with nonoperative measures, such as activity modification, weight-bearing protection, or bracing, drilling of the subchondral bone has emerged as the gold standard of management. Several techniques of drilling exist, including transarticular drilling, retroarticular drilling, and notch drilling. Although each technique has been shown to be effective in small retrospective studies, higher-powered prospective comparative studies are needed to better elucidate their relative advantages and disadvantages.

  12. Nonpharmacologic techniques for promoting sleep.

    PubMed

    Cole, Roger J

    2005-04-01

    Athletes could benefit from simple, self-administered, nonpharmacologic techniques for promoting sleep onset. A wealth of physiologic evidence and limited clinical data support several potential methods that might be conveniently applied at or near bedtime. These include inverted posture, skin warming/core cooling, motor relaxation, sensory withdrawal/masking, breathing techniques, and cognitive relaxation. Each holds promise as a possible element of a comprehensive sleep management program, but all need further investigation to confirm their efficacy or to determine optimal methods of application. PMID:15892928

  13. Selected photographic techniques, a compilation

    NASA Technical Reports Server (NTRS)

    1971-01-01

    A selection has been made of methods, devices, and techniques developed in the field of photography during implementation of space and nuclear research projects. These items include many adaptations, variations, and modifications to standard hardware and practice, and should prove interesting to both amateur and professional photographers and photographic technicians. This compilation is divided into two sections. The first section presents techniques and devices that have been found useful in making photolab work simpler, more productive, and higher in quality. Section two deals with modifications to and special applications for existing photographic equipment.

  14. Urologic imaging and interventional techniques

    SciTech Connect

    Bush, W.H.

    1989-01-01

    This book provides an overview of all imaging modalities and invasive techniques of the genitourinary system. Three general chapters discuss ionic and nonionic contrast media, the management of reactions to contrast media, and radiation doses from various uroradiologic procedures. Chapters are devoted to intravenous pyelography, computed tomography, magnetic resonance imaging, ultrasound, nuclear medicine, lymphography, arteriography, and venography. Two chapters discuss the pediatric applications of uroradiology and ultrasound. Two chapters integrate the various imaging techniques of the upper and lower genitourinary systems into an algorithmic approach for various pathologic entities.

  15. Multiple frequency atmospheric radar techniques

    NASA Astrophysics Data System (ADS)

    Stitt, Gary Richard

    The use of multiple frequency coding to improve the vertical resolution of pulsed-Doppler very high frequency atmospheric radars, especially with regards to the two-frequency techniques known as frequency domain interferometry (FDI), is presented. This technique consists of transmitting alternate pulses on two distinct carrier frequencies. The two resulting time series are used to evaluate the normalized cross-correlation function, whose magnitude and phase are related to the thickness and position of a scattering layer. These same time series are also used to evaluate cross-spectra, which yield magnitude and phase values for each Doppler frequency component of the return signal.

  16. Techniques and indications in radiology

    SciTech Connect

    Lange, S.

    1987-01-01

    The stated purpose of this book is to review modern radiologic diagnostic techniques as applied to the study of the kidney and urinary tract, and their pertinent indications. This goal is partially accomplished in the first two segments of the book, which consist of about 100 pages. These include a synoptic description of various techniques - including classic uroradiologic studies such as excretory urography and retrograde pyelography, plus sonography, computed tomography, angiography, and nuclear medicine. The diagnostic signs and the differential diagnoses are fairly well described, aided by a profusion of tables and diagrams. The overall quality of the reproduction of the illustrations is good.

  17. Molten salt techniques. Volume 3

    SciTech Connect

    Lovering, D.G.; Gale, R.J.

    1987-01-01

    This collection of five papers on molten salts deals with the following specific topics: the actinides and their salts, including their availability along with techniques and equipment for their handling, preparation, purification, and physical property measurement; cryolite systems and methods for their handling, preparation, and thermodynamic and physicochemical property assessment, as well as the use of electrodes in molten cryolite; the theory, construction, and application of reference electrodes for molten salt electrolytes; neutron diffraction in molten salt systems including isotope exchange methods for sample preparation; and dry boxes and inert atmosphere techniques for molten salt handling and analysis.

  18. Computerized proof techniques for undergraduates

    NASA Astrophysics Data System (ADS)

    Smith, Christopher J.; Tefera, Akalu; Zeleke, Aklilu

    2012-12-01

    The use of computer algebra systems such as Maple and Mathematica is becoming increasingly important and widespread in mathematics learning, teaching and research. In this article, we present computerized proof techniques of Gosper, Wilf-Zeilberger and Zeilberger that can be used for enhancing the teaching and learning of topics in discrete mathematics. We demonstrate by examples how one can use these computerized proof techniques to raise students' interests in the discovery and proof of mathematical identities and enhance their problem-solving skills.

  19. Pattern recognition techniques in Polarimetry

    NASA Astrophysics Data System (ADS)

    Ariste, Arturo López

    2015-10-01

    Sparsity is a property of data by which it can be represented using a small number of patterns. It is the key concept behind an evergrowing list of mathematical techniques for handling data and recover from it signals or information in conditions previously thought impossible. The application of those techniques to spectropolarimetric data is relatively straightforward. We present three examples of such application: the use of Principal Component Analysis to invert the magnetic field in solar prominences from spectropolarimetry of the He D3 line, the removal of fringes from spectropolarimetric data with Relevance Vector Machines, and the retrieval of high resolution spectra from low resolution data with Compressed Sensing.

  20. Selenium incorporation using recombinant techniques

    SciTech Connect

    Walden, Helen

    2010-04-01

    An overview of techniques for recombinant incorporation of selenium and subsequent purification and crystallization of the resulting labelled protein. Using selenomethionine to phase macromolecular structures is common practice in structure determination, along with the use of selenocysteine. Selenium is consequently the most commonly used heavy atom for MAD. In addition to the well established recombinant techniques for the incorporation of selenium in prokaryal expression systems, there have been recent advances in selenium labelling in eukaryal expression, which will be discussed. Tips and things to consider for the purification and crystallization of seleno-labelled proteins are also included.

  1. Thick film silicon growth techniques

    NASA Technical Reports Server (NTRS)

    Bates, H. E.; Jewett, D. N.; Mlavsky, A. I.; White, V. E.

    1974-01-01

    One inch wide silicon ribbons up to 14 inches long have been produced from graphite dies. Several different techniques have been employed to improve the semiconductor purity of silicon. This has resulted in a general increase in quality although the techniques involved have not been optimized. The power factor of uncoated ribbon solar cells produced for material evaluation has increased to approximately 75% of those evaluation cells made from commercial silicon. The present limitation is believed due to low lifetime. Additional work has continued with new die materials; however, only composite dies of SiO2 and C show significant potential at this time.

  2. Multi-scale Shock Technique

    2009-08-01

    The code to be released is a new addition to the LAMMPS molecular dynamics code. LAMMPS is developed and maintained by Sandia, is publicly available, and is used widely by both natioanl laboratories and academics. The new addition to be released enables LAMMPS to perform molecular dynamics simulations of shock waves using the Multi-scale Shock Simulation Technique (MSST) which we have developed and has been previously published. This technique enables molecular dynamics simulations of shockmore » waves in materials for orders of magnitude longer timescales than the direct, commonly employed approach.« less

  3. Mass spectrometry. [review of techniques

    NASA Technical Reports Server (NTRS)

    Burlingame, A. L.; Kimble, B. J.; Derrick, P. J.

    1976-01-01

    Advances in mass spectrometry (MS) and its applications over the past decade are reviewed in depth, with annotated literature references. New instrumentation and techniques surveyed include: modulated-beam MS, chromatographic MS on-line computer techniques, digital computer-compatible quadrupole MS, selected ion monitoring (mass fragmentography), and computer-aided management of MS data and interpretation. Areas of application surveyed include: organic MS and electron impact MS, field ionization kinetics, appearance potentials, translational energy release, studies of metastable species, photoionization, calculations of molecular orbitals, chemical kinetics, field desorption MS, high pressure MS, ion cyclotron resonance, biochemistry, medical/clinical chemistry, pharmacology, and environmental chemistry and pollution studies.

  4. Effect of the suture technique on postoperative pain, swelling and trismus after removal of lower third molars: A randomized clinical trial

    PubMed Central

    Gómez-Santos, Laila; Sánchez-Torres, Alba; Herráez-Vilas, José-María

    2015-01-01

    Background To evaluate the intensity of pain, swelling and trismus after the removal of impacted lower third molars comparing two different suture techniques of the triangular flap: the complete suture of the distal incision and relieving incision and the partial suture with only one suture knot for closure of the corner of the flap and the closure of the distal incision, without suturing the relieving incision. Material and Methods A prospective, randomized, crossover clinical trial was conducted in 40 patients aged from 18 to 45 years who underwent surgical extraction of impacted lower third molars at the Department of Oral Surgery in the Odontological Hospital of the University of Barcelona during the year 2011. Patients were randomly divided in 2 groups. Two different techniques (hermetical closure and partial closure of the wound) were performed separated by a one month washout period in each patient. Postoperative pain, swelling and trismus were evaluated prior to the surgical procedure and also at 2 and 7 days post operatively. Results No statistically significant differences were observed for pain (p<0.06), trismus (p<0.71) and swelling (p<0.05) between the test and the control group. However, the values of the three parameters related to the test group were lower than those for the control group. Conclusions Partial closure of the flap without suturing the relieving incision after surgical extraction of lower third molars reduces operating time and it does not produce any postoperative complications compared with complete closure of the wound. Key words: Third molar, surgical flaps, suture techniques, postoperative pain, swelling, trismus. PMID:25662551

  5. EDITORIAL: Imaging Systems and Techniques Imaging Systems and Techniques

    NASA Astrophysics Data System (ADS)

    Giakos, George; Yang, Wuqiang; Petrou, M.; Nikita, K. S.; Pastorino, M.; Amanatiadis, A.; Zentai, G.

    2011-10-01

    This special feature on Imaging Systems and Techniques comprises 27 technical papers, covering essential facets in imaging systems and techniques both in theory and applications, from research groups spanning three different continents. It mainly contains peer-reviewed articles from the IEEE International Conference on Imaging Systems and Techniques (IST 2011), held in Thessaloniki, Greece, as well a number of articles relevant to the scope of this issue. The multifaceted field of imaging requires drastic adaptation to the rapid changes in our society, economy, environment, and the technological revolution; there is an urgent need to address and propose dynamic and innovative solutions to problems that tend to be either complex and static or rapidly evolving with a lot of unknowns. For instance, exploration of the engineering and physical principles of new imaging systems and techniques for medical applications, remote sensing, monitoring of space resources and enhanced awareness, exploration and management of natural resources, and environmental monitoring, are some of the areas that need to be addressed with urgency. Similarly, the development of efficient medical imaging techniques capable of providing physiological information at the molecular level is another important area of research. Advanced metabolic and functional imaging techniques, operating on multiple physical principles, using high resolution and high selectivity nanoimaging techniques, can play an important role in the diagnosis and treatment of cancer, as well as provide efficient drug-delivery imaging solutions for disease treatment with increased sensitivity and specificity. On the other hand, technical advances in the development of efficient digital imaging systems and techniques and tomographic devices operating on electric impedance tomography, computed tomography, single-photon emission and positron emission tomography detection principles are anticipated to have a significant impact on a

  6. The Split-Stem Technique

    ERIC Educational Resources Information Center

    Carter, Roy A.

    1972-01-01

    Describes a procedure useful for investigating the effects of substances on plant growth and development. A bean seedling's stem is partially split, and each half is placed in a different nutrient solution. Suggestions for the instructional use of the technique are made. (AL)

  7. Single-Donor Leukophoretic Technique

    NASA Technical Reports Server (NTRS)

    Eberhardt, R. N.

    1977-01-01

    Leukocyte separation-and-retrieval device utilizes granulocyte and monocyte property of leukoadhesion to glass surfaces as basis of their separation from whole blood. Device is used with single donor technique and has application in biological and chemical processing, veterinary research and clinical care.

  8. Cobbler's Technique for Iridodialysis Repair

    PubMed Central

    Pandav, Surinder Singh; Gupta, Parul Chawla; Singh, Rishi Raj; Das, Kalpita; Kaushik, Sushmita; Raj, Srishti; Ram, Jagat

    2016-01-01

    We describe a novel “Cobbler's technique” for iridodialysis repair in the right eye of a patient aged 18 years, with a traumatic iridodialysis secondary to open globe injury with an iron rod. Our technique is simple with easy surgical maneuvers, that is, effective for repairing iridodialysis. The “Cobbler's technique” allows a maximally functional and cosmetic result for iridodialysis. PMID:26957855

  9. Selected microgravity combustion diagnostic techniques

    NASA Technical Reports Server (NTRS)

    Griffin, Devon W.; Greenberg, Paul S.

    1993-01-01

    During FY 1989-1992, several diagnostic techniques for studying microgravity combustion have moved from the laboratory to use in reduced-gravity facilities. This paper discusses current instrumentation for rainbow schlieren deflectometry and thermophoretic sampling of soot from gas jet diffusion flames.

  10. Techniques for hot structures testing

    NASA Technical Reports Server (NTRS)

    Deangelis, V. Michael; Fields, Roger A.

    1990-01-01

    Hot structures testing have been going on since the early 1960's beginning with the Mach 6, X-15 airplane. Early hot structures test programs at NASA-Ames-Dryden focused on operational testing required to support the X-15 flight test program, and early hot structures research projects focused on developing lab test techniques to simulate flight thermal profiles. More recent efforts involved numerous large and small hot structures test programs that served to develop test methods and measurement techniques to provide data that promoted the correlation of test data with results from analytical codes. In Nov. 1988 a workshop was sponsored that focused on the correlation of hot structures test data with analysis. Limited material is drawn from the workshop and a more formal documentation is provided of topics that focus on hot structures test techniques used at NASA-Ames-Dryden. Topics covered include the data acquisition and control of testing, the quartz lamp heater systems, current strain and temperature sensors, and hot structures test techniques used to simulate the flight thermal environment in the lab.

  11. Radioactive-gas separation technique

    NASA Technical Reports Server (NTRS)

    Haney, R.; King, K. J.; Nellis, D. O.; Nisson, R. S.; Robling, P.; Womack, W.

    1977-01-01

    Cryogenic technique recovers gases inexpensively. Method uses differences in vapor pressures, melting points, and boiling points of components in gaseous mixture. Series of temperature and pressure variations converts gases independently to solid and liquid states, thereby simplifying separation. Apparatus uses readily available cryogen and does not require expensive refrigeration equipment.

  12. Laparoscopic pyelolithotomy: optimizing surgical technique.

    PubMed

    Salvadó, José A; Guzmán, Sergio; Trucco, Cristian A; Parra, Claudio A

    2009-04-01

    The classic approach to renal stone disease includes shockwave lithotripsy, ureteroscopy or percutaneous nephrolithotripsy, and, in some cases, a combination of both. The usefulness of laparoscopy in this regard remains debated. In this report and video, we present our technique of laparoscopic pyelolithotomy assisted by flexible instrumentation to achieve maximal stone clearance in a selected group of patients.

  13. Diagnostic techniques for thermal plasmas

    SciTech Connect

    Fincke, J.R.; Snyder, S.C.; Swank, W.D.; Haggard, D.C.; Reynolds, L.D.

    1994-12-31

    The plasma diagnostic techniques discussed are Rayleigh and coherent Thomson scattering, Coherent-Anti-Stokes-Raman Spectroscopy (CARS) and enthalpy probes. The quantities measured are heavy species and electron temperature, ionized fraction, plasma composition, and velocity. Examples of results from both subsonic and supersonic jets are presented and limitations discussed.

  14. Brain Friendly Techniques: Mind Mapping

    ERIC Educational Resources Information Center

    Goldberg, Cristine

    2004-01-01

    Mind Mapping can be called the Swiss Army Knife for the brain, a total visual thinking tool or a multi-handed thought catcher. Invented by Tony Buzan in the early 1970s and used by millions around the world, it is a method that can be a part of a techniques repertoire when teaching information literacy, planning, presenting, thinking, and so…

  15. Survey of Biochemical Separation Techniques

    ERIC Educational Resources Information Center

    Nilsson, Melanie R.

    2007-01-01

    A simple laboratory exercise is illustrated that exposes students to wide range of separation techniques in one laboratory program and provides a nice complement to a project-oriented program. Students have learned the basic principles of syringe filtration, centricon, dialysis, gel filtration and solid-phase extraction methodologies and have got…

  16. Microprocessor Simulation: A Training Technique.

    ERIC Educational Resources Information Center

    Oscarson, David J.

    1982-01-01

    Describes the design and application of a microprocessor simulation using BASIC for formal training of technicians and managers and as a management tool. Illustrates the utility of the modular approach for the instruction and practice of decision-making techniques. (SK)

  17. Time domain period determination techniques

    NASA Technical Reports Server (NTRS)

    Stellingwerf, R. F.

    1980-01-01

    Two simple period determination schemes are discussed. They are well suited to problems involving non-sinusoidal periodic phenomena sampled at a few irregularly spaced points. Statistical properties are discussed. The techniques are applied to the double mode Cepheids BK Cen and TU Cas as test cases.

  18. Superresolution techniques and ISAR imaging

    NASA Astrophysics Data System (ADS)

    Gabriel, W. F.

    High-resolution optimal estimation techniques are applied to the problem of radar imaging of rotating objects, sometimes referred to as ISAR (inverse synthetic array radar) imaging. Typical digital range-Doppler processing operations are described, utilizing two spectral estimation techniques. Quality ISAR images have been obtained from such processing, and particular examples, which are based on simulated data generated from point-target models of rotating objects, are shown. The first example is a so-called merry-go-round of 24 point-targets, and the MLM (maximum-likelihood method) algorithm is utilized to process a three-dimensional range-Doppler image estimate. The second example is a rotating boom along which are located 15 point-targets including a doublet, a triplet, and a quadruplet cluster that require superresolution techniques to resolve in the Doppler domain. It is concluded that superresolution techniques offer a viable alternative to conventional DFT (discrete Fourier transform) ISAR image processing and should permit either higher resolution images from the same data samples or equal-quality images from significantly fewer data samples.

  19. Biopsy techniques for intraocular tumors

    PubMed Central

    Rishi, Pukhraj; Dhami, Abhinav; Biswas, Jyotirmay

    2016-01-01

    Biopsy involves the surgical removal of a tissue specimen for histopathologic evaluation. Most intraocular tumors are reliably diagnosed based on the clinical evaluation or with noninvasive diagnostic techniques. However, accurately diagnosing a small percentage of tumors can be challenging. A tissue biopsy is thus needed to establish a definitive diagnosis and plan the requisite treatment. From fine-needle aspiration biopsy (FNAB) to surgical excision, all tissue collection techniques have been studied in the literature. Each technique has its indications and limitations. FNAB has been reported to provide for 88–95% reliable and safe ophthalmic tumor diagnosis and has gained popularity for prognostic purposes and providing eye conserving treatment surgeries. The technique and instrumentation for biopsy vary depending upon the tissue involved (retina, choroid, subretinal space, vitreous, and aqueous), suspected diagnosis, size, location, associated retinal detachment, and clarity of the media. The cytopathologist confers a very important role in diagnosis and their assistance plays a key role in managing and planning the treatment for malignancies. PMID:27488148

  20. Low background techniques in CANDLES

    NASA Astrophysics Data System (ADS)

    Nakajima, K.; Iida, T.; Kishimoto, T.; Matsuoka, K.; Nomachi, M.; Umehara, S.; Chan, W. M.; Kakubata, H.; Li, X.; Maeda, T.; Ohata, T.; Temuge, B.; Tetsuno, K.; Trang, V. T. T.; Uehara, T.; Yoshida, S.; Morishita, K.; Ogawa, I.; Sakamoto, K.; Tamagawa, Y.; Yoshizawa, M.; Fushimi, K.; Hazama, R.; Naktani, N.; Suzuki, K.

    2015-08-01

    CANDLES is a double beta decay experiment using 48Ca in CaF2 crystals. The measurement is being performed with prototype detector (CANDLES III) for high sensitive measurement in the future. Recent status of detector improvements and background reduction techniques are described in this paper.

  1. Practical Techniques for Achieving Consensus.

    ERIC Educational Resources Information Center

    Kline, John A.

    Consensus is important in the making of a policy decision. If a decision is reached without consensus, morale and unit satisfaction may both suffer. With genuine consensus, a unit tends to willingly support and implement the new policy. After analyzing how observed small groups had actually reached consensus, the following ten techniques were…

  2. Techniques in Advanced Language Teaching.

    ERIC Educational Resources Information Center

    Ager, D. E.

    1967-01-01

    For ease of presentation, advanced grammar teaching techniques are briefly considered under the headings of structuralism (belief in the effectiveness of presenting grammar rules) and contextualism (belief in the maximum use by students of what they know in the target language). The structuralist's problem of establishing a syllabus is discussed…

  3. Identifying Major Techniques of Persuasion.

    ERIC Educational Resources Information Center

    Makosky, Vivian Parker

    1985-01-01

    The purpose of this class exercise is to increase undergraduate psychology students' awareness of common persuasion techniques used in advertising, including the appeal to or creation of needs, social and prestige suggestion, and the use of emotionally loaded words and images. Television commercials and magazine advertisements are used as…

  4. Low background techniques in CANDLES

    SciTech Connect

    Nakajima, K. E-mail: nkyohei@u-fukui.ac.jp; Iida, T.; Matsuoka, K.; Nomachi, M.; Umehara, S.; Kishimoto, T.; Chan, W. M.; Kakubata, H.; Li, X.; Maeda, T.; Ohata, T.; Temuge, B.; Tetsuno, K.; Trang, V. T. T.; Uehara, T.; Yoshida, S.; Morishita, K.; Ogawa, I.; Sakamoto, K.; Tamagawa, Y.; and others

    2015-08-17

    CANDLES is a double beta decay experiment using {sup 48}Ca in CaF{sub 2} crystals. The measurement is being performed with prototype detector (CANDLES III) for high sensitive measurement in the future. Recent status of detector improvements and background reduction techniques are described in this paper.

  5. Techniques Associated With Robotic Telescopes

    NASA Astrophysics Data System (ADS)

    Klotz, Alain

    2010-10-01

    Robotic observatories use modern techniques based on industrial automation. In this paper, we describe components to use and the importance of their reliability. The software is also the key of the scientific success. It must include management of external events such as VOEvents.

  6. Multimodal Revision Techniques in Webtexts

    ERIC Educational Resources Information Center

    Ball, Cheryl E.

    2014-01-01

    This article examines how an online scholarly journal, "Kairos: Rhetoric, Technology, Pedagogy," mentors authors to revise their webtexts (interactive, digital media scholarship) for publication. Using an editorial pedagogy in which multimodal and rhetorical genre theories are merged with revision techniques found in process-based…

  7. Objective techniques for psychological assessment

    NASA Technical Reports Server (NTRS)

    Wortz, E.; Hendrickson, W.; Ross, T.

    1973-01-01

    A literature review and a pilot study are used to develop psychological assessment techniques for determining objectively the major aspects of the psychological state of an astronaut. Relationships between various performance and psychophysiological variables and between those aspects of attention necessary to engage successfully in various functions are considered in developing a paradigm to be used for collecting data in manned isolation chamber experiments.

  8. New Techniques for Particle Acclerators

    SciTech Connect

    Sessler, Andrew M.

    1990-06-01

    A review is presented of the new techniques which have been proposed for use in particle accelerators. Attention is focused upon those areas where significant progress has been made in the last two years--in particular, upon two-beam accelerators, wakefield accelerators, and plasma focusers.

  9. Nephroureteral Stents: Principles and Techniques

    PubMed Central

    Makramalla, Abouelmagd; Zuckerman, Darryl A.

    2011-01-01

    Nephroureteral stents including antegrade, retrograde, or internal (double-J) stents are routinely placed by interventional radiologists. The purpose of this review is to provide a detailed and comprehensive description of indications, contraindications, technique, and various technical challenges of these procedures. Also pre- and postprocedure management of patients will be discussed including routine follow-up and dealing with potential complications. PMID:23204635

  10. Optical interconnection techniques for Hypercube

    NASA Technical Reports Server (NTRS)

    Johnston, A. R.; Bergman, L. A.; Wu, W. H.

    1988-01-01

    Direct free-space optical interconnection techniques are described for the Hypercube concurrent processor machine using a holographic optical element. Computational requirements and optical constraints on implementation are briefly summarized with regard to topology, power consumption, and available technologies. A hybrid lens/HOE approach is described that can support an eight-dimensional cube of 256 nodes.

  11. Rhinoplasty – indications and techniques

    PubMed Central

    Tasman, Abel-Jan

    2008-01-01

    Rhinoplasty is considered to be one of the most challenging procedures in otolaryngology head and neck surgery. Meticulous planning and excellent surgical skills are pre-requisites for reproducible good outcomes. More than 100 years after the first rhinoplasty, many controversies regarding indication and techniques remain unresolved. The aim of this article is to review current concepts and arguments. PMID:22073085

  12. Museum Techniques in Fundamental Education.

    ERIC Educational Resources Information Center

    United Nations Educational, Scientific, and Cultural Organization, Paris (France).

    Some museum techniques and methods can be used in fundamental educational programs without elaborate buildings or equipment; exhibitions should be based on valid presumptions and should take into account the "common sense" beliefs of people for whom the exhibit is designed. They can be used profitably in the economic development of local cultural…

  13. A measurement technique for hydroxyacetone

    SciTech Connect

    Klotz, P.J.

    1999-10-04

    Hydroxyacetone (HA) is mainly produced in the atmosphere from oxidation of hydrocarbons of the type, CH{sub 3}(R)C{double{underscore}bond}CH{sub 2}. Tuazon and Atkinson (1990) reported HA yield of 41% from the OH-initiated oxidation of methacrolein in the presence of NOx. Since methacrolein is a major product of isoprene oxidation (Carter and Atkinson, 1996), isoprene, a key biogenic hydrocarbon, is therefore expected to be an important source for HA. Consequently, knowledge of ambient concentration of HA would provide information needed to examine the applicability of isoprene reaction mechanisms developed in laboratory and to assess the contribution of isoprene to photooxidant production. The commonly used GC-FID technique involving cryo-focusing is unsuitable for HA owing to HA's thermal instability. When subjected to a temperature of 100 C for only a few seconds, HA was found to disappear completely. Since HA is highly soluble in water, the authors developed a wet chemical technique similar in principle to the one they reported earlier, namely, derivatization following liquid scrubbing. To increase the sensitivity, they adopted a fluorescence detection scheme based on o-phthaldialdehyde (OPA) chemistry. The technique was deployed in the field during two measurement periods at a NARSTO site located on Long Island, New York. The authors report the principle and the operation of this technique and the results obtained from these field studies.

  14. Teaching Techniques in Clinical Chemistry.

    ERIC Educational Resources Information Center

    Wilson, Diane

    This master's thesis presents several instructional methods and techniques developed for each of eleven topics or subject areas in clinical chemistry: carbohydrate metabolism, lipid metabolism, diagnostic enzymology, endocrinology, toxicology, quality control, electrolytes, acid base balance, hepatic function, nonprotein nitrogenous compounds, and…

  15. Developments in functional neuroimaging techniques

    SciTech Connect

    Aine, C.J.

    1995-03-01

    A recent review of neuroimaging techniques indicates that new developments have primarily occurred in the area of data acquisition hardware/software technology. For example, new pulse sequences on standard clinical imagers and high-powered, rapidly oscillating magnetic field gradients used in echo planar imaging (EPI) have advanced MRI into the functional imaging arena. Significant developments in tomograph design have also been achieved for monitoring the distribution of positron-emitting radioactive tracers in the body (PET). Detector sizes, which pose a limit on spatial resolution, have become smaller (e.g., 3--5 mm wide) and a new emphasis on volumetric imaging has emerged which affords greater sensitivity for determining locations of positron annihilations and permits smaller doses to be utilized. Electromagnetic techniques have also witnessed growth in the ability to acquire data from the whole head simultaneously. EEG techniques have increased their electrode coverage (e.g., 128 channels rather than 16 or 32) and new whole-head systems are now in use for MEG. But the real challenge now is in the design and implementation of more sophisticated analyses to effectively handle the tremendous amount of physiological/anatomical data that can be acquired. Furthermore, such analyses will be necessary for integrating data across techniques in order to provide a truly comprehensive understanding of the functional organization of the human brain.

  16. Thematic Repetition as Rhetorical Technique.

    ERIC Educational Resources Information Center

    Allen, Jo

    1991-01-01

    Explores William Harvey's work, "On the Motion of the Heart and Blood in Animals." Highlights Harvey's fear of publication and his strategies for reducing resistance to his ideas. Underscores his use of circular references, metaphors, and organizational techniques that enhance and demonstrate his underlying thesis. (SG)

  17. Optical multiple object tracking techniques

    NASA Technical Reports Server (NTRS)

    Liu, Hua-Kuang; Chao, Tien-Hsin

    1989-01-01

    Two multichannel multiple-object tracking techniques are reviewed. In the diffraction grating technique, the input scene is picked up by a TV camera and imaged onto a liquid-crystal light valve (LCLV), and the output side of the light valve is illuminated with a suitably polarized and collimated coherent laser beam to yield a reflected beam with polarization modulated according to the intensity of the incoherent input. This reflected beam passes through a beam splitter cube and an analyzer, resulting in an intensity modulated coherent image. An array of spectrum islands containing the information of the input appears after crossing a contact screen/lens combination. In the multiple-focus hololens technique, the scene of moving objects is sent into the LCTVSLM through a camera; a collimated laser beam is incident upon the LCTV screen; a low-pass filter is inserted between the LCTVSLM and the hololens for the removal of the high order diffractions due to the grid structure of the LCTV. The feasibility of the LCTVSLM and multiple-focus hololens technique is demonstrated.

  18. Laparoscopic pyelolithotomy: optimizing surgical technique.

    PubMed

    Salvadó, José A; Guzmán, Sergio; Trucco, Cristian A; Parra, Claudio A

    2009-04-01

    The classic approach to renal stone disease includes shockwave lithotripsy, ureteroscopy or percutaneous nephrolithotripsy, and, in some cases, a combination of both. The usefulness of laparoscopy in this regard remains debated. In this report and video, we present our technique of laparoscopic pyelolithotomy assisted by flexible instrumentation to achieve maximal stone clearance in a selected group of patients. PMID:19358685

  19. Computerized Proof Techniques for Undergraduates

    ERIC Educational Resources Information Center

    Smith, Christopher J.; Tefera, Akalu; Zeleke, Aklilu

    2012-01-01

    The use of computer algebra systems such as Maple and Mathematica is becoming increasingly important and widespread in mathematics learning, teaching and research. In this article, we present computerized proof techniques of Gosper, Wilf-Zeilberger and Zeilberger that can be used for enhancing the teaching and learning of topics in discrete…

  20. Digital synchronization and communication techniques

    NASA Technical Reports Server (NTRS)

    Lindsey, William C.

    1992-01-01

    Information on digital synchronization and communication techniques is given in viewgraph form. Topics covered include phase shift keying, modems, characteristics of open loop digital synchronizers, an open loop phase and frequency estimator, and a digital receiver structure using an open loop estimator in a decision directed architecture.

  1. Advanced Tools and Techniques for Formal Techniques in Aerospace Systems

    NASA Technical Reports Server (NTRS)

    Knight, John C.

    2005-01-01

    This is the final technical report for grant number NAG-1-02101. The title of this grant was "Advanced Tools and Techniques for Formal Techniques In Aerospace Systems". The principal investigator on this grant was Dr. John C. Knight of the Computer Science Department, University of Virginia, Charlottesville, Virginia 22904-4740. This report summarizes activities under the grant during the period 7/01/2002 to 9/30/2004. This report is organized as follows. In section 2, the technical background of the grant is summarized. Section 3 lists accomplishments and section 4 lists students funded under the grant. In section 5, we present a list of presentations given at various academic and research institutions about the research conducted. Finally, a list of publications generated under this grant is included in section 6.

  2. The Use of Expressive Techniques in Counseling

    ERIC Educational Resources Information Center

    Bradley, Loretta J.; Whiting, Peggy; Hendricks, Bret; Parr, Gerald; Jones, Eugene Gordon, Jr.

    2008-01-01

    This manuscript explores and identifies the use of expressive techniques in counseling. Although verbal techniques are important, sometimes the best of verbal techniques are not sufficient. Creative, expressive techniques can add a new, important dimension to counseling. Such expressive techniques as cinema, art, and music are described to help…

  3. School Business Management Techniques: A Compendium.

    ERIC Educational Resources Information Center

    Cresswell, Anthony; And Others

    The intent of this document is to describe approximately 30 management science and organizational behavioral techniques with practical applications in school business management. Each technique is described by the mechanics of using the technique, specific applications of the technique, and requirements and constraints in the use of the technique.…

  4. Historical Techniques of Lie Detection.

    PubMed

    Vicianova, Martina

    2015-08-01

    Since time immemorial, lying has been a part of everyday life. For this reason, it has become a subject of interest in several disciplines, including psychology. The purpose of this article is to provide a general overview of the literature and thinking to date about the evolution of lie detection techniques. The first part explores ancient methods recorded circa 1000 B.C. (e.g., God's judgment in Europe). The second part describes technical methods based on sciences such as phrenology, polygraph and graphology. This is followed by an outline of more modern-day approaches such as FACS (Facial Action Coding System), functional MRI, and Brain Fingerprinting. Finally, after the familiarization with the historical development of techniques for lie detection, we discuss the scope for new initiatives not only in the area of designing new methods, but also for the research into lie detection itself, such as its motives and regulatory issues related to deception.

  5. A tire contact solution technique

    NASA Technical Reports Server (NTRS)

    Tielking, J. T.

    1983-01-01

    An efficient method for calculating the contact boundary and interfacial pressure distribution was developed. This solution technique utilizes the discrete Fourier transform to establish an influence coefficient matrix for the portion of the pressurized tire surface that may be in the contact region. This matrix is used in a linear algebra algorithm to determine the contact boundary and the array of forces within the boundary that are necessary to hold the tire in equilibrium against a specified contact surface. The algorithm also determines the normal and tangential displacements of those points on the tire surface that are included in the influence coefficient matrix. Displacements within and outside the contact region are calculated. The solution technique is implemented with a finite-element tire model that is based on orthotropic, nonlinear shell of revolution elements which can respond to nonaxisymmetric loads. A sample contact solution is presented.

  6. Apoptosis Evaluation by Electrochemical Techniques.

    PubMed

    Yin, Jian; Miao, Peng

    2016-03-01

    Apoptosis has close relevance to pathology, pharmacology, and toxicology. Accurate and convenient detection of apoptosis would be beneficial for biological study, clinical diagnosis, and drug development. Based on distinct features of apoptotic cells, a diversity of analytical techniques have been exploited for sensitive analysis of apoptosis, such as surface plasmon resonance, electrochemical methods, flow cytometry, and some imaging assays. Among them, the features of simplicity, easy operation, low cost, and high sensitivity make electrochemical techniques powerful tools to investigate electron-transfer processes of in vitro biological systems. In this contribution, a general overview of current knowledge on various technical approaches for apoptosis evaluation is provided. Furthermore, recently developed electrochemical biosensors for detecting apoptotic cells and their advantages over traditional methods are summarized. One of the main considerations focuses on designing the recognition elements based on various biochemical events during apoptosis.

  7. Historical Techniques of Lie Detection

    PubMed Central

    Vicianova, Martina

    2015-01-01

    Since time immemorial, lying has been a part of everyday life. For this reason, it has become a subject of interest in several disciplines, including psychology. The purpose of this article is to provide a general overview of the literature and thinking to date about the evolution of lie detection techniques. The first part explores ancient methods recorded circa 1000 B.C. (e.g., God’s judgment in Europe). The second part describes technical methods based on sciences such as phrenology, polygraph and graphology. This is followed by an outline of more modern-day approaches such as FACS (Facial Action Coding System), functional MRI, and Brain Fingerprinting. Finally, after the familiarization with the historical development of techniques for lie detection, we discuss the scope for new initiatives not only in the area of designing new methods, but also for the research into lie detection itself, such as its motives and regulatory issues related to deception. PMID:27247675

  8. [Studies on male sterilization techniques].

    PubMed

    Lee, H Y

    1975-06-01

    After a review of the theory, incidence in Korea, indications, complications, and operative technique of vasectomy, clinical observations on 2 procedures are given. Vas reanastomosis was performed on 185 men, aged 19-58, using general anesthesia. Ejaculates of 178 of the men showed 81% contained viable sperm. more than 10 years, 58%). Later pregnancies were reported by 35% of the men. Reversible vas occlusion by insertion of intravasal thread (IVT) was performed on 544 men under local anesthesia. Sperm passage was occluded in 96% of the men. After 9 months, 42 men had the IVT removed; 83% had viable sperm 1 month later. Advantages of the IVT technique are 1) simplicity of reversibility, 2) low cost, 3) no postoperative pain or discomfort, and 4) outpatient/local anesthesia procedure. A disadvantage is the lower success rate of vas occlusion due to luminal dilation around the IVT.

  9. Historical Techniques of Lie Detection.

    PubMed

    Vicianova, Martina

    2015-08-01

    Since time immemorial, lying has been a part of everyday life. For this reason, it has become a subject of interest in several disciplines, including psychology. The purpose of this article is to provide a general overview of the literature and thinking to date about the evolution of lie detection techniques. The first part explores ancient methods recorded circa 1000 B.C. (e.g., God's judgment in Europe). The second part describes technical methods based on sciences such as phrenology, polygraph and graphology. This is followed by an outline of more modern-day approaches such as FACS (Facial Action Coding System), functional MRI, and Brain Fingerprinting. Finally, after the familiarization with the historical development of techniques for lie detection, we discuss the scope for new initiatives not only in the area of designing new methods, but also for the research into lie detection itself, such as its motives and regulatory issues related to deception. PMID:27247675

  10. A new atrial septostomy technique.

    PubMed

    Park, S C; Zuberbuhler, J R; Neches, W H; Lenox, C C; Zoltun, R A

    1975-01-01

    Balloon atrial septostomy is usually ineffective if the atrial septum is thickened. A technique for incising the atrial septum is described. A no. 6 French catheter was modified to enclose a tiny surgical blade. The distal end of the blade was pivoted to the catheter tip, and the proximal end was attached to a guide wire in the catheter lumen. Advancing the guide wire protruded the blade through a slit in the long axis of the tip of the catheter. Atrial septostomy was performed in five newborn lambs in vivo and in adult dog hearts and human hearts in vitro by advancing the catheter tip across the atrial septum with the blade retracted and withdrawing it to the right atrium with the blade extended. Eight to 12 mm lacerations of the atrial septum were produced and could be extended by subsequent balloon septostomy. The technique may be useful when balloon septostomy has been ineffective.

  11. Barley Transformation Using Biolistic Techniques

    NASA Astrophysics Data System (ADS)

    Harwood, Wendy A.; Smedley, Mark A.

    Microprojectile bombardment or biolistic techniques have been widely used for cereal transformation. These methods rely on the acceleration of gold particles, coated with plasmid DNA, into plant cells as a method of directly introducing the DNA. The first report of the generation of fertile, transgenic barley plants used biolistic techniques. However, more recently Agrobacterium-mediated transformation has been adopted as the method of choice for most cereals including barley. Biolistic procedures are still important for some barley transformation applications and also provide transient test systems for the rapid checking of constructs. This chapter describes methods for the transformation of barley using biolistic procedures and also highlights the use of the technology in transient assays.

  12. Techniques for Quantifying Phytoplankton Biodiversity

    NASA Astrophysics Data System (ADS)

    Johnson, Zackary I.; Martiny, Adam C.

    2015-01-01

    The biodiversity of phytoplankton is a core measurement of the state and activity of marine ecosystems. In the context of historical approaches, we review recent major advances in the technologies that have enabled deeper characterization of the biodiversity of phytoplankton. In particular, high-throughput sequencing of single loci/genes, genomes, and communities (metagenomics) has revealed exceptional phylogenetic and genomic diversity whose breadth is not fully constrained. Other molecular tools—such as fingerprinting, quantitative polymerase chain reaction, and fluorescence in situ hybridization—have provided additional insight into the dynamics of this diversity in the context of environmental variability. Techniques for characterizing the functional diversity of community structure through targeted or untargeted approaches based on RNA or protein have also greatly advanced. A wide range of techniques is now available for characterizing phytoplankton communities, and these tools will continue to advance through ongoing improvements in both technology and data interpretation.

  13. Rapid response gas injection technique.

    PubMed

    Komar, J J

    1978-10-01

    A unique gas injection technique has been developed which has rapid response and is capable of supplying gas flowrates up to 5 kg/s at pressures of 3.45 x 10(6) N/m(2). Rise times to equilibrium pressure varied from 7 to 15 ms over the operating range. The reliability, excellent repeatibility, and uniform pressure have shown the system to be superior to previously utilized expansion tube gas injection techniques associated with very short duration impulse test facilities. The achievement of precise timing control of the valve opening permitted a complex electronic sequencing of facility events. An additional feature of automatic gas supply shut-off resulted in significant cost savings when rare gases were used as injectants. PMID:18698978

  14. Metabolomics techniques for nanotoxicity investigations.

    PubMed

    Lv, Mengying; Huang, Wanqiu; Chen, Zhipeng; Jiang, Hulin; Chen, Jiaqing; Tian, Yuan; Zhang, Zunjian; Xu, Fengguo

    2015-01-01

    Nanomaterials are commonly defined as engineered structures with at least one dimension of 100 nm or less. Investigations of their potential toxicological impact on biological systems and the environment have yet to catch up with the rapid development of nanotechnology and extensive production of nanoparticles. High-throughput methods are necessary to assess the potential toxicity of nanoparticles. The omics techniques are well suited to evaluate toxicity in both in vitro and in vivo systems. Besides genomic, transcriptomic and proteomic profiling, metabolomics holds great promises for globally evaluating and understanding the molecular mechanism of nanoparticle-organism interaction. This manuscript presents a general overview of metabolomics techniques, summarizes its early application in nanotoxicology and finally discusses opportunities and challenges faced in nanotoxicology. PMID:26168257

  15. Ultrasound techniques in space medicine.

    PubMed

    Atkov OYu; Bednenko, V S; Fomina, G A

    1987-09-01

    Ultrasound examinations have been performed on 15 cosmonauts who have remained in orbit for flights ranging from 2.5 to 8 months in duration. Soviet researchers have combined hemodynamic assessments with parallel attempts to develop improved ultrasound techniques and equipment for use onboard space stations. These techniques and equipment are reviewed, as are findings relative to exercise effects on hemodynamic changes. In general, longitudinal echocardiographic studies have suggested that 1) few differences exist between resting preflight and on-orbit cardiac contractility measures; 2) declines in orthostatic stability after long-term flights are not due to deterioration of the myocardial functional state; and 3) lower stroke volumes and heart rate increases occurring during exertion may be considered compensatory hemodynamic resettings rather than indications of disturbed left ventricular contractility.

  16. Surface Characterization Techniques: An Overview

    NASA Technical Reports Server (NTRS)

    Miyoshi, Kazuhisa

    2002-01-01

    To understand the benefits that surface modifications provide, and ultimately to devise better ones, it is necessary to study the physical, mechanical, and chemical changes they cause. This chapter surveys classical and leading-edge developments in surface structure and property characterization methodologies. The primary emphases are on the use of these techniques as they relate to surface modifications, thin films and coatings, and tribological engineering surfaces and on the implications rather than the instrumentation.

  17. Low background techniques in XMASS

    SciTech Connect

    Takeda, Atsushi

    2011-04-27

    The XMASS project aims to detect pp and {sup 7}Be solar neutrinos, neutrino-less double beta decay, and dark matter searches using ultra-pure liquid xenon. The first stage of XMASS project is concentrated on dark matter searches using 800 kg liquid xenon detector which requires low background and low threshold. Several techniques applied to XMASS detector for low background will be presented.

  18. Multilevel techniques for nonelliptic problems

    NASA Technical Reports Server (NTRS)

    Jespersen, D. C.

    1981-01-01

    Multigrid and multilevel methods are extended to the solution of nonelliptic problems. A framework for analyzing these methods is established. A simple nonelliptic problem is given, and it is shown how a multilevel technique can be used for its solution. Emphasis is on smoothness properties of eigenvectors and attention is drawn to the possibility of conditioning the eigensystem so that eigenvectors have the desired smoothness properties.

  19. Acoustic techniques in nuclear safeguards

    SciTech Connect

    Olinger, C.T.; Sinha, D.N.

    1995-07-01

    Acoustic techniques can be employed to address many questions relevant to current nuclear technology needs. These include establishing and monitoring intrinsic tags and seals, locating holdup in areas where conventional radiation-based measurements have limited capability, process monitoring, monitoring containers for corrosion or changes in pressure, and facility design verification. These acoustics applications are in their infancy with respect to safeguards and nuclear material management, but proof-of-principle has been demonstrated in many of the areas listed.

  20. Radon assay and purification techniques

    SciTech Connect

    Simgen, Hardy

    2013-08-08

    Radon is a source of background in many astroparticle physics experiments searching for rare low energy events. In this paper an overview about radon in the field is given including radon detection techniques, radon sources and material screening with respect to radon emanation. Finally, also the problem of long-lived radioactive {sup 222}Rn-daughters and the question of gas purification from radon is addressed.

  1. Video techniques applied to astrometry

    NASA Astrophysics Data System (ADS)

    Thuillot, W.; Arlot, J.-E.; Fettig, S.; Colas, F.

    1991-03-01

    This paper reports on the application of video techniques to the astrometry of fast-moving objects in the solar system. Various phenomena may be observed for astrometric purposes, and 2D photometry is well adapted for this. This paper describes the method used to acquire and analyze such observations and gives the first results obtained concerning two observations of mutual phenomena of the Galilean satellites of Jupiter which occurred during the last (1985) campaign of observations.

  2. Climbing techniques for bridge inspection

    NASA Astrophysics Data System (ADS)

    Kaslan, Erol C.

    1998-03-01

    California has about 24,000 publicly owned bridges that require routine structural evaluations to comply with National Bridge Inspection Standard (NBIS) mandates. Of these, about 800 are identified as possessing fatigue prone or fracture critical details requiring thorough tactile investigations. Gaining access to bridge elements to perform these investigations has become increasingly difficult and costly. The traditional uses of under bridge inspection trucks, lift equipment and rigging are economically and practically limited by bridge size, structure type, traffic demands and support costs. In some cases, bridges that have become damaged by earthquakes cannot safely support the loads of heavy personnel lift equipment. The California Department of Transportation (Caltrans)'s Office of Structural Materials and Office of Structure Maintenance and Investigations evaluated the use of rock climbing and mountaineering techniques as an alternative means of gaining access for bridge inspections. Under a small research grant, a bridge climbing training course was developed through a local University of California outdoor recreation group and 7 engineers and technicians were initially trained. A comprehensive Code of Safe Practices was created and standards of training, procedures and equipment required for bridge inspections were established. A successful climb investigation on a large, previously inaccessible arch bridge was completed at the end of the training that proved the techniques safe, economical and effective. Within one year, 20 bridge maintenance engineers were trained, and a formal program was established to organize, schedule, equip and certify engineers and technicians for bridge climbing. Several other offices within Caltrans as well as the California Department of Water Resources have since adopted these techniques for specialized structural inspection tasks. Climbing techniques are now used routinely in California as an alterative means of gaining access

  3. Data mining and visualization techniques

    DOEpatents

    Wong, Pak Chung; Whitney, Paul; Thomas, Jim

    2004-03-23

    Disclosed are association rule identification and visualization methods, systems, and apparatus. An association rule in data mining is an implication of the form X.fwdarw.Y where X is a set of antecedent items and Y is the consequent item. A unique visualization technique that provides multiple antecedent, consequent, confidence, and support information is disclosed to facilitate better presentation of large quantities of complex association rules.

  4. Survey of Header Compression Techniques

    NASA Technical Reports Server (NTRS)

    Ishac, Joseph

    2001-01-01

    This report provides a summary of several different header compression techniques. The different techniques included are: (1) Van Jacobson's header compression (RFC 1144); (2) SCPS (Space Communications Protocol Standards) header compression (SCPS-TP, SCPS-NP); (3) Robust header compression (ROHC); and (4) The header compression techniques in RFC2507 and RFC2508. The methodology for compression and error correction for these schemes are described in the remainder of this document. All of the header compression schemes support compression over simplex links, provided that the end receiver has some means of sending data back to the sender. However, if that return path does not exist, then neither Van Jacobson's nor SCPS can be used, since both rely on TCP (Transmission Control Protocol). In addition, under link conditions of low delay and low error, all of the schemes perform as expected. However, based on the methodology of the schemes, each scheme is likely to behave differently as conditions degrade. Van Jacobson's header compression relies heavily on the TCP retransmission timer and would suffer an increase in loss propagation should the link possess a high delay and/or bit error rate (BER). The SCPS header compression scheme protects against high delay environments by avoiding delta encoding between packets. Thus, loss propagation is avoided. However, SCPS is still affected by an increased BER (bit-error-rate) since the lack of delta encoding results in larger header sizes. Next, the schemes found in RFC2507 and RFC2508 perform well for non-TCP connections in poor conditions. RFC2507 performance with TCP connections is improved by various techniques over Van Jacobson's, but still suffers a performance hit with poor link properties. Also, RFC2507 offers the ability to send TCP data without delta encoding, similar to what SCPS offers. ROHC is similar to the previous two schemes, but adds additional CRCs (cyclic redundancy check) into headers and improves

  5. Monolithic microcircuit techniques and processes

    NASA Technical Reports Server (NTRS)

    Kennedy, B. W.

    1972-01-01

    Brief discussions of the techniques used to make dielectric and metal thin film depositions for monolithic circuits are presented. Silicon nitride deposition and the properties of silicon nitride films are discussed. Deposition of dichlorosilane and thermally grown silicon dioxide are reported. The deposition and thermal densification of borosilicate, aluminosilicate, and phosphosilicate glasses are discussed. Metallization for monolithic circuits and the characteristics of thin films are also included.

  6. A MEASUREMENT TECHNIQUE FOR HYDROXYACETONE.

    SciTech Connect

    KLOTZ,P.J.

    1999-10-04

    Hydroxyacetone (HA) is mainly produced in the atmosphere from oxidation of hydrocarbons of the type, CH{sub 3}(R)C=CH{sub 2}. Tuazon and Atkinson (1990) reported HA yield of 41% from the OH-initiated oxidation of methacrolein in the presence of NO{sub x}. Since methacrolein is a major product of isoprene oxidation (Carter and Atkinson, 1996), isoprene, a key biogenic hydrocarbon, is therefore expected to be an important source for HA. Consequently, knowledge of ambient concentration of HA would provide information needed to examine the applicability of isoprene reaction mechanisms developed in laboratory and to assess the contribution of isoprene to photooxidant production. The commonly used GC-FID technique involving cryo-focusing is unsuitable for HA owing to HA's thermal instability. When subjected to a temperature of 100 C for only a few seconds, HA was found to disappear completely. Since HA is highly soluble in water (it's Henry's law constant being {approx}2 x 10{sup 4} M atm{sup -1} at 20 C, Zhou and Lee, unpublished data), we developed a wet chemical technique similar in principle to the one we reported earlier (Lee and Zhou, 1993), namely, based on derivatization following liquid scrubbing. To increase the sensitivity, we adopted a fluorescence detection scheme based on o-phthaldialdehyde (OPA) chemistry. The technique was deployed in the field during two measurement periods at a NARSTO site located on Long Island (LI), New York. We report the principle and the operation of this technique and the results obtained from these field studies.

  7. Flip-chip and backside techniques.

    SciTech Connect

    Bernhard-Hofer, Karoline; Barton, Daniel Lee; Cole, Edward Isaac, Jr.

    2010-08-01

    State-of-the-art techniques for failure localization and design modification through bulk silicon are essential for multi-level metallization and new, flip chip packaging methods. The tutorial reviews the transmission of light through silicon, sample preparation, and backside defect localization techniques that are both currently available and under development. The techniques covered include emission microscopy, scanning laser microscope based techniques (electrooptic techniques, LIVA and its derivatives), and other non-IR based tools (FIB, e-beam techniques, etc.).

  8. Computational intelligence techniques in bioinformatics.

    PubMed

    Hassanien, Aboul Ella; Al-Shammari, Eiman Tamah; Ghali, Neveen I

    2013-12-01

    Computational intelligence (CI) is a well-established paradigm with current systems having many of the characteristics of biological computers and capable of performing a variety of tasks that are difficult to do using conventional techniques. It is a methodology involving adaptive mechanisms and/or an ability to learn that facilitate intelligent behavior in complex and changing environments, such that the system is perceived to possess one or more attributes of reason, such as generalization, discovery, association and abstraction. The objective of this article is to present to the CI and bioinformatics research communities some of the state-of-the-art in CI applications to bioinformatics and motivate research in new trend-setting directions. In this article, we present an overview of the CI techniques in bioinformatics. We will show how CI techniques including neural networks, restricted Boltzmann machine, deep belief network, fuzzy logic, rough sets, evolutionary algorithms (EA), genetic algorithms (GA), swarm intelligence, artificial immune systems and support vector machines, could be successfully employed to tackle various problems such as gene expression clustering and classification, protein sequence classification, gene selection, DNA fragment assembly, multiple sequence alignment, and protein function prediction and its structure. We discuss some representative methods to provide inspiring examples to illustrate how CI can be utilized to address these problems and how bioinformatics data can be characterized by CI. Challenges to be addressed and future directions of research are also presented and an extensive bibliography is included. PMID:23891719

  9. Airborne dust particle counting techniques.

    PubMed

    Sharma, S G; Prasad, B D

    2006-03-01

    The paper briefly describes an electro-optical system for counting of dust particles, which is based on the scattering phenomena. Utilizing the scattering of light by various size particles present in the environment, various particle counting techniques have been developed in order to measure the scattered intensity of light. Light scatters in all directions but much more in the so-called near forward direction 17( composite function) off axis, at 163( composite function) from the light source in the visible range. On the basis of two techniques, the right angle and forward angle scattering, opto-mechanical systems have been developed which measure scattered intensity and particulate matter. The forward scattering Nephelometer is more sensitive and therefore is more suitable for pollution monitoring than the right angle scattering Nephelometer. Whereas the right angle scattering Nephelometer has the utility in extremely low concentration in ppb level owing to the excellent light trap efficiency in comparison to forward scattering Nephelometer. In this paper measurement techniques and measurement results associated with design and development of a real time particle analyser are also discussed.

  10. Simultaneous multislice (SMS) imaging techniques

    PubMed Central

    Barth, Markus; Breuer, Felix; Koopmans, Peter J.; Poser, Benedikt A.

    2015-01-01

    Simultaneous multislice imaging (SMS) using parallel image reconstruction has rapidly advanced to become a major imaging technique. The primary benefit is an acceleration in data acquisition that is equal to the number of simultaneously excited slices. Unlike in‐plane parallel imaging this can have only a marginal intrinsic signal‐to‐noise ratio penalty, and the full acceleration is attainable at fixed echo time, as is required for many echo planar imaging applications. Furthermore, for some implementations SMS techniques can reduce radiofrequency (RF) power deposition. In this review the current state of the art of SMS imaging is presented. In the Introduction, a historical overview is given of the history of SMS excitation in MRI. The following section on RF pulses gives both the theoretical background and practical application. The section on encoding and reconstruction shows how the collapsed multislice images can be disentangled by means of the transmitter pulse phase, gradient pulses, and most importantly using multichannel receiver coils. The relationship between classic parallel imaging techniques and SMS reconstruction methods is explored. The subsequent section describes the practical implementation, including the acquisition of reference data, and slice cross‐talk. Published applications of SMS imaging are then reviewed, and the article concludes with an outlook and perspective of SMS imaging. Magn Reson Med 75:63–81, 2016. © 2015 The Authors. Magnetic Resonance in Medicine Published by Wiley Periodicals, Inc. on behalf of International Society of Medicine in Resonance. PMID:26308571

  11. Techniques for Specifying Bug Patterns

    SciTech Connect

    Quinlan, D J; Vuduc, R W; Misherghi, G

    2007-04-30

    We present our on-going work to develop techniques for specifying source code signatures of bug patterns. Specifically, we discuss two approaches. The first approach directly analyzes a program in the intermediate representation (IR) of the ROSE compiler infrastructure using ROSE's API. The second analyzes the program using the bddbddb system of Lam, Whaley, et al.. In this approach, we store the IR produced by ROSE as a relational database, express patterns as declarative inference rules on relations in the language Datalog, and bddbddb implements the Datalog programs using binary decision diagram (BDD) techniques. Both approaches readily apply to large-scale applications, since ROSE provides full type analysis, control flow, and other available analysis information. In this paper, we primarily consider bug patterns expressed with respect to the structure of the source code or the control flow, or both. More complex techniques to specify patterns that are functions of data flow properties may be addressed by either of the above approaches, but are not directly treated here. Our Datalog-based work includes explicit support for expressing patterns on the use of the Message Passing Interface (MPI) in parallel distributed memory programs. We show examples of this on-going work as well.

  12. Control technique for planetary rover

    NASA Technical Reports Server (NTRS)

    Nakatani, Ichiro; Kubota, Takashi; Adachi, Tadashi; Saitou, Hiroaki; Okamoto, Sinya

    1994-01-01

    Beginning next century, several schemes for sending a planetary rover to the moon or Mars are being planned. As part of the development program, autonomous navigation technology is being studied to allow the rover the ability to move autonomously over a long range of unknown planetary surface. In the previous study, we ran the autonomous navigation experiment on an outdoor test terrain by using a rover test-bed that was controlled by a conventional sense-plan-act method. In some cases during the experiment, a problem occurred with the rover moving into untraversable areas. To improve this situation, a new control technique has been developed that gives the rover the ability of reacting to the outputs of the proximity sensors, a reaction behavior if you will. We have developed a new rover test-bed system on which an autonomous navigation experiment was performed using the newly developed control technique. In this outdoor experiment, the new control technique effectively produced the control command for the rover to avoid obstacles and be guided to the goal point safely.

  13. Simultaneous multislice (SMS) imaging techniques.

    PubMed

    Barth, Markus; Breuer, Felix; Koopmans, Peter J; Norris, David G; Poser, Benedikt A

    2016-01-01

    Simultaneous multislice imaging (SMS) using parallel image reconstruction has rapidly advanced to become a major imaging technique. The primary benefit is an acceleration in data acquisition that is equal to the number of simultaneously excited slices. Unlike in-plane parallel imaging this can have only a marginal intrinsic signal-to-noise ratio penalty, and the full acceleration is attainable at fixed echo time, as is required for many echo planar imaging applications. Furthermore, for some implementations SMS techniques can reduce radiofrequency (RF) power deposition. In this review the current state of the art of SMS imaging is presented. In the Introduction, a historical overview is given of the history of SMS excitation in MRI. The following section on RF pulses gives both the theoretical background and practical application. The section on encoding and reconstruction shows how the collapsed multislice images can be disentangled by means of the transmitter pulse phase, gradient pulses, and most importantly using multichannel receiver coils. The relationship between classic parallel imaging techniques and SMS reconstruction methods is explored. The subsequent section describes the practical implementation, including the acquisition of reference data, and slice cross-talk. Published applications of SMS imaging are then reviewed, and the article concludes with an outlook and perspective of SMS imaging.

  14. Perioperative Acupuncture and Related Techniques

    PubMed Central

    Chernyak, Grigory V.; Sessler, Daniel I.

    2005-01-01

    Acupuncture and related techniques are increasingly practiced in conventional medical settings, and the number of patients willing to use these techniques is increasing. Despite more than 30 years of research, the exact mechanism of action and efficacy of acupuncture have not been established. Furthermore, most aspects of acupuncture have yet to be adequately tested. There thus remains considerable controversy about the role of acupuncture in clinical medicine. Acupuncture apparently does not reduce volatile anesthetic requirement by a clinically important amount. However, preoperative sedation seems to be a promising application of acupuncture in perioperative settings. Acupuncture may be effective for postoperative pain relief but requires a high level of expertise by the acupuncture practitioner. Acupuncture and related techniques can be used for treatment and prophylaxis of postoperative nausea and vomiting in routine clinical practice in combination with, or as an alternative to, conventional antiemetics when administered before induction of general anesthesia. Summary Statement: The use of acupuncture for perioperative analgesia, nausea and vomiting, sedation, anesthesia, and complications is reviewed. PMID:15851892

  15. NASA standard: Trend analysis techniques

    NASA Technical Reports Server (NTRS)

    1988-01-01

    This Standard presents descriptive and analytical techniques for NASA trend analysis applications. Trend analysis is applicable in all organizational elements of NASA connected with, or supporting, developmental/operational programs. Use of this Standard is not mandatory; however, it should be consulted for any data analysis activity requiring the identification or interpretation of trends. Trend Analysis is neither a precise term nor a circumscribed methodology, but rather connotes, generally, quantitative analysis of time-series data. For NASA activities, the appropriate and applicable techniques include descriptive and graphical statistics, and the fitting or modeling of data by linear, quadratic, and exponential models. Usually, but not always, the data is time-series in nature. Concepts such as autocorrelation and techniques such as Box-Jenkins time-series analysis would only rarely apply and are not included in this Standard. The document presents the basic ideas needed for qualitative and quantitative assessment of trends, together with relevant examples. A list of references provides additional sources of information.

  16. Techniques to accelerate dynamic psychotherapy.

    PubMed

    Fosha, D; Slowiaczek, M L

    1997-01-01

    The techniques described above outline specific ways to deepen the patient's affective experience within an emotionally close therapeutic relationship. When effective, they all enhance the patient/therapist bond, raise self-esteem, reduce defensiveness and anxiety, and facilitate emotional healing. Psychodynamic treatment, long or short, is a complex process uniquely constructed by each therapist/patient pair. AEDP strategies are not intended as recipes for treatment. Good dynamic work depends on the therapist's ability to grasp the patient's capacities and limitations, understand relational dynamics, and interact with the patient in an empathically attuned, emotionally receptive, and flexible way. In that context, these strategies can be helpful tools to facilitate and accelerate the process. The choices made by AEDP--privileging adaptive strivings over defensive reactions, the stance of emotional engagement rather than neutrality and abstinence, the focus on health and change over pathology and stasis--are informed by traditional STDP aims to maximize depth, effectiveness, and efficiency. AEDP's contribution is a set of techniques relying on a response repertoire that is available to a wide range of therapists. Therapists can use these techniques to be more effective while simultaneously retaining the experience of speaking with patients in an authentic voice.

  17. EDITORIAL: Imaging systems and techniques Imaging systems and techniques

    NASA Astrophysics Data System (ADS)

    Yang, Wuqiang; Giakos, George; Nikita, Konstantina; Pastorino, Matteo; Karras, Dimitrios

    2009-10-01

    The papers in this special issue focus on providing the state-of-the-art approaches and solutions to some of the most challenging imaging areas, such as the design, development, evaluation and applications of imaging systems, measuring techniques, image processing algorithms and instrumentation, with an ultimate aim of enhancing the measurement accuracy and image quality. This special issue explores the principles, engineering developments and applications of new imaging systems and techniques, and encourages broad discussion of imaging methodologies, shaping the future and identifying emerging trends. The multi-faceted field of imaging requires drastic adaptation to the rapid changes in our society, economy, environment and technological evolution. There is an urgent need to address new problems, which tend to be either static but complex, or dynamic, e.g. rapidly evolving with time, with many unknowns, and to propose innovative solutions. For instance, the battles against cancer and terror, monitoring of space resources and enhanced awareness, management of natural resources and environmental monitoring are some of the areas that need to be addressed. The complexity of the involved imaging scenarios and demanding design parameters, e.g. speed, signal-to-noise ratio (SNR), specificity, contrast, spatial resolution, scatter rejection, complex background and harsh environments, necessitate the development of a multi-functional, scalable and efficient imaging suite of sensors, solutions driven by innovation, and operation on diverse detection and imaging principles. Efficient medical imaging techniques capable of providing physiological information at the molecular level present another important research area. Advanced metabolic and functional imaging techniques, operating on multiple physical principles, and using high-resolution, high-selectivity nano-imaging methods, quantum dots, nanoparticles, biomarkers, nanostructures, nanosensors, micro-array imaging chips

  18. Simulation verification techniques study. Subsystem simulation validation techniques

    NASA Technical Reports Server (NTRS)

    Duncan, L. M.; Reddell, J. P.; Schoonmaker, P. B.

    1974-01-01

    Techniques for validation of software modules which simulate spacecraft onboard systems are discussed. An overview of the simulation software hierarchy for a shuttle mission simulator is provided. A set of guidelines for the identification of subsystem/module performance parameters and critical performance parameters are presented. Various sources of reference data to serve as standards of performance for simulation validation are identified. Environment, crew station, vehicle configuration, and vehicle dynamics simulation software are briefly discussed from the point of view of their interfaces with subsystem simulation modules. A detailed presentation of results in the area of vehicle subsystems simulation modules is included. A list of references, conclusions and recommendations are also given.

  19. Swept Impact Seismic Technique (SIST)

    USGS Publications Warehouse

    Park, C.B.; Miller, R.D.; Steeples, D.W.; Black, R.A.

    1996-01-01

    A coded seismic technique is developed that can result in a higher signal-to-noise ratio than a conventional single-pulse method does. The technique is cost-effective and time-efficient and therefore well suited for shallow-reflection surveys where high resolution and cost-effectiveness are critical. A low-power impact source transmits a few to several hundred high-frequency broad-band seismic pulses during several seconds of recording time according to a deterministic coding scheme. The coding scheme consists of a time-encoded impact sequence in which the rate of impact (cycles/s) changes linearly with time providing a broad range of impact rates. Impact times used during the decoding process are recorded on one channel of the seismograph. The coding concept combines the vibroseis swept-frequency and the Mini-Sosie random impact concepts. The swept-frequency concept greatly improves the suppression of correlation noise with much fewer impacts than normally used in the Mini-Sosie technique. The impact concept makes the technique simple and efficient in generating high-resolution seismic data especially in the presence of noise. The transfer function of the impact sequence simulates a low-cut filter with the cutoff frequency the same as the lowest impact rate. This property can be used to attenuate low-frequency ground-roll noise without using an analog low-cut filter or a spatial source (or receiver) array as is necessary with a conventional single-pulse method. Because of the discontinuous coding scheme, the decoding process is accomplished by a "shift-and-stacking" method that is much simpler and quicker than cross-correlation. The simplicity of the coding allows the mechanical design of the source to remain simple. Several different types of mechanical systems could be adapted to generate a linear impact sweep. In addition, the simplicity of the coding also allows the technique to be used with conventional acquisition systems, with only minor modifications.

  20. Research Techniques Made Simple: Skin Carcinogenesis Models: Xenotransplantation Techniques.

    PubMed

    Mollo, Maria Rosaria; Antonini, Dario; Cirillo, Luisa; Missero, Caterina

    2016-02-01

    Xenotransplantation is a widely used technique to test the tumorigenic potential of human cells in vivo using immunodeficient mice. Here we describe basic technologies and recent advances in xenotransplantation applied to study squamous cell carcinomas (SCCs) of the skin. SCC cells isolated from tumors can either be cultured to generate a cell line or injected directly into mice. Several immunodeficient mouse models are available for selection based on the experimental design and the type of tumorigenicity assay. Subcutaneous injection is the most widely used technique for xenotransplantation because it involves a simple procedure allowing the use of a large number of cells, although it may not mimic the original tumor environment. SCC cell injections at the epidermal-to-dermal junction or grafting of organotypic cultures containing human stroma have also been used to more closely resemble the tumor environment. Mixing of SCC cells with cancer-associated fibroblasts can allow the study of their interaction and reciprocal influence, which can be followed in real time by intradermal ear injection using conventional fluorescent microscopy. In this article, we will review recent advances in xenotransplantation technologies applied to study behavior of SCC cells and their interaction with the tumor environment in vivo.

  1. Flexible time domain averaging technique

    NASA Astrophysics Data System (ADS)

    Zhao, Ming; Lin, Jing; Lei, Yaguo; Wang, Xiufeng

    2013-09-01

    Time domain averaging(TDA) is essentially a comb filter, it cannot extract the specified harmonics which may be caused by some faults, such as gear eccentric. Meanwhile, TDA always suffers from period cutting error(PCE) to different extent. Several improved TDA methods have been proposed, however they cannot completely eliminate the waveform reconstruction error caused by PCE. In order to overcome the shortcomings of conventional methods, a flexible time domain averaging(FTDA) technique is established, which adapts to the analyzed signal through adjusting each harmonic of the comb filter. In this technique, the explicit form of FTDA is first constructed by frequency domain sampling. Subsequently, chirp Z-transform(CZT) is employed in the algorithm of FTDA, which can improve the calculating efficiency significantly. Since the signal is reconstructed in the continuous time domain, there is no PCE in the FTDA. To validate the effectiveness of FTDA in the signal de-noising, interpolation and harmonic reconstruction, a simulated multi-components periodic signal that corrupted by noise is processed by FTDA. The simulation results show that the FTDA is capable of recovering the periodic components from the background noise effectively. Moreover, it can improve the signal-to-noise ratio by 7.9 dB compared with conventional ones. Experiments are also carried out on gearbox test rigs with chipped tooth and eccentricity gear, respectively. It is shown that the FTDA can identify the direction and severity of the eccentricity gear, and further enhances the amplitudes of impulses by 35%. The proposed technique not only solves the problem of PCE, but also provides a useful tool for the fault symptom extraction of rotating machinery.

  2. Techniques for siding manual phalanges.

    PubMed

    Christensen, Angi M

    2009-12-15

    Identifying the anatomical origin of skeletal elements is a basic and important part of a forensic anthropological investigation, but techniques for determining the side and ray of the phalanges are conspicuously scarce in the physical anthropology literature. Features of particular phalanges are important to aspects of archaeological and paleoanthropological studies, as well as for identification and trauma analysis in forensic cases. Correct siding of phalanges may therefore be quite critical in certain contexts. This study evaluates several siding techniques previously developed and/or described in a recent study by Case and Heilman (2000). Unlike in their study where observers were provided all phalange positional information except for side, observations in this study were undertaken with no positional information provided thus making the examinations more similar to those performed in a forensic context. Tests of phalange siding techniques were carried out on two skeletal samples: the Terry Collection at the Smithsonian's National Museum of Natural History where the ray and side of phalanges are documented and phalange collections are often complete, and the Bass Collection at the University of Tennessee where phalange positional information is undocumented and where phalange collections are seldom complete. The features described by Case and Heilman were found to work quite well. In the documented (Terry) sample, there was a high rate of correct siding, up to 100% for several phalanges. In the undocumented (Bass) sample, the features could be used to side the phalanges to a reasonable degree of certainty, and certainty increased when both sides of a particular phalange were present. Finally, several other useful siding and ray identification features were identified. PMID:19853390

  3. Blob-enhanced reconstruction technique

    NASA Astrophysics Data System (ADS)

    Castrillo, Giusy; Cafiero, Gioacchino; Discetti, Stefano; Astarita, Tommaso

    2016-09-01

    A method to enhance the quality of the tomographic reconstruction and, consequently, the 3D velocity measurement accuracy, is presented. The technique is based on integrating information on the objects to be reconstructed within the algebraic reconstruction process. A first guess intensity distribution is produced with a standard algebraic method, then the distribution is rebuilt as a sum of Gaussian blobs, based on location, intensity and size of agglomerates of light intensity surrounding local maxima. The blobs substitution regularizes the particle shape allowing a reduction of the particles discretization errors and of their elongation in the depth direction. The performances of the blob-enhanced reconstruction technique (BERT) are assessed with a 3D synthetic experiment. The results have been compared with those obtained by applying the standard camera simultaneous multiplicative reconstruction technique (CSMART) to the same volume. Several blob-enhanced reconstruction processes, both substituting the blobs at the end of the CSMART algorithm and during the iterations (i.e. using the blob-enhanced reconstruction as predictor for the following iterations), have been tested. The results confirm the enhancement in the velocity measurements accuracy, demonstrating a reduction of the bias error due to the ghost particles. The improvement is more remarkable at the largest tested seeding densities. Additionally, using the blobs distributions as a predictor enables further improvement of the convergence of the reconstruction algorithm, with the improvement being more considerable when substituting the blobs more than once during the process. The BERT process is also applied to multi resolution (MR) CSMART reconstructions, permitting simultaneously to achieve remarkable improvements in the flow field measurements and to benefit from the reduction in computational time due to the MR approach. Finally, BERT is also tested on experimental data, obtaining an increase of the

  4. Interference techniques in fluorescence microscopy

    NASA Astrophysics Data System (ADS)

    Dogan, Mehmet

    We developed a set of interference-based optical microscopy techniques to study biological structures through nanometer-scale axial localization of fluorescent biomarkers. Spectral self-interference fluorescence microscopy (SSFM) utilizes interference of direct and reflected waves emitted from fluorescent molecules in the vicinity of planar reflectors to reveal the axial position of the molecules. A comprehensive calculation algorithm based on Green's function formalism is presented to verify the validity of approximations used in a far-field approach that describes the emission of fluorescent markers near interfaces. Using the validated model, theoretical limits of axial localization were determined with emphasis given to numerical aperture (NA) dependence of localization uncertainty. SSFM was experimentally demonstrated in conformational analysis of nucleoproteins. In particular, interaction between surface-tethered 75-mer double strand DNA and integration host factor (IHF) protein was probed on Si-SiO2 substrates by determining the axial position of fluorescent labels attached to the free ends of DNA molecules. Despite its sub-nanometer precision axial localization capability, SSFM lacks high lateral resolution due to the low-NA requirement for planar reflectors. We developed a second technique, 4Pi-SSFM, which improves the lateral resolution of a conventional SSFM system by an order of magnitude while achieving nanometer-scale axial localization precision. Using two opposing high-NA objectives, fluorescence signal is interferometrically collected and spectral interference pattern is recorded. Axial position of emitters is found from analysis of the spectra. The 4Pi-SSFM technique was experimentally demonstrated by determining the surface profiles of fabricated glass surfaces and outer membranes of Shigella, a type of Gram-negative bacteria. A further discussion is presented to localize surface O antigen, which is an important oligosaccharide structure in the

  5. Advances in wound debridement techniques.

    PubMed

    Nazarko, Linda

    2015-06-01

    Dead and devitalised tissue interferes with the process of wound healing. Debridement is a natural process that occurs in all wounds and is crucial to healing; it reduces the bacterial burden in a wound and promotes effective inflammatory responses that encourage the formation of healthy granulation tissue (Wolcott et al, 2009). Wound care should be part of holistic patient care. Recent advances in debridement techniques include: biosurgery, hydrosurgery, mechanical debridement, and ultrasound. Biosurgery and mechanical debridement can be practiced by nonspecialist nurses and can be provided in a patient's home, thus increasing the patient's access to debridement therapy and accelerating wound healing.

  6. EPR techniques for space biodosimetry

    SciTech Connect

    Haskell, E.; Hayes, R.; Kenner, G.; Sholom, S.; Chumak, V.

    1996-12-31

    Retrospective dosimetry of tooth enamel has become an increasingly complex and difficult discipline to undertake while still attaining accuracy. The paper provides a review of the major obstacles, advances and pertinent phenomenon associated with low level retrospective dosimetry of human tooth enamel. Also covered is the many sources of error in EPR dosimetry, their potential solutions, as well as the different analysis and scanning techniques in use with their prospective pros and cons. Prospective directions for new approaches, methods, and instruments are also reviewed.

  7. Techniques for Automated Performance Analysis

    SciTech Connect

    Marcus, Ryan C.

    2014-09-02

    The performance of a particular HPC code depends on a multitude of variables, including compiler selection, optimization flags, OpenMP pool size, file system load, memory usage, MPI configuration, etc. As a result of this complexity, current predictive models have limited applicability, especially at scale. We present a formulation of scientific codes, nodes, and clusters that reduces complex performance analysis to well-known mathematical techniques. Building accurate predictive models and enhancing our understanding of scientific codes at scale is an important step towards exascale computing.

  8. Measurement Techniques for Clock Jitter

    NASA Technical Reports Server (NTRS)

    Lansdowne, Chatwin; Schlesinger, Adam

    2012-01-01

    NASA is in the process of modernizing its communications infrastructure to accompany the development of a Crew Exploration Vehicle (CEV) to replace the shuttle. With this effort comes the opportunity to infuse more advanced coded modulation techniques, including low-density parity-check (LDPC) codes that offer greater coding gains than the current capability. However, in order to take full advantage of these codes, the ground segment receiver synchronization loops must be able to operate at a lower signal-to-noise ratio (SNR) than supported by equipment currently in use.

  9. Diffraction techniques in engineering applications

    SciTech Connect

    Kozarczek, K.J.; Hubbard, C.R.; Watkins, T.R.; Wang, X.L.; Spooner, S.

    1995-12-31

    Diffraction techniques applied to crystalline materials provide quantitative information about the crystallographic structure and mechanical condition of the material. Those two characteristics influence the chemical, physical, and mechanical properties of a Component. A concerted application of x-ray and neutron diffraction allows one to comprehensively study the bulk and subsurface variations of such material characteristics as crystallographic texture, residual stress, and cold work. The Residual Stress User Center at the Oak Ridge National Laboratory offers academic and industrial researchers both neutron and x-ray diffraction capabilities. Recent examples of the application of work related to thin film, metal, ceramic and composite material technologies are presented.

  10. Techniques for objective outcome assessment.

    PubMed

    Hesbach, Amie Lamoreaux

    2007-11-01

    Companion animal rehabilitation, a collaborative practice of physical therapy and veterinary medicine, can only demonstrate the effectiveness of its theories, techniques, interventions, and modalities through evidence-based practice, utilizing standardized, reliable, and valid outcome measures, correlated with objective diagnostic data. This essay examines existing and potential objective outcome measures utilized in companion animal rehabilitation and physical therapy regarding pain, vital signs, body condition and composition, range of motion, muscle strength, inflammation, functional mobility, and gait. Discussion is included of the traditional disablement model and the evolution of the physical therapy diagnosis, prognosis, and plan of care. PMID:18198782

  11. Research in millimeter wave techniques

    NASA Technical Reports Server (NTRS)

    Mcmillan, R. W.

    1987-01-01

    The areas of millimeter wave (MMW) research include atmospheric propagation and radiometry, advanced MMW component design with emphasis on quasi-optical techniques, and the development of MMW receivers, especially those using subharmonic mixers. Calculations of atmospheric attenuation and radiometric antenna temperature were made in the range 100 to 700 GHz, together with measurements of atmospheric antenna temperature near 95 and 183 GHz. Quasi-optical components designed include lenses, mirrors, and wire grid devices, as well as feedhorns for interference with waveguide components. Subharmonic mixers with state-of-the-art performance at 183 GHz were also developed. Each of these areas of research is summarized.

  12. 21 CFR 820.250 - Statistical techniques.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Statistical techniques. 820.250 Section 820.250...) MEDICAL DEVICES QUALITY SYSTEM REGULATION Statistical Techniques § 820.250 Statistical techniques. (a... statistical techniques required for establishing, controlling, and verifying the acceptability of...

  13. 21 CFR 820.250 - Statistical techniques.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Statistical techniques. 820.250 Section 820.250...) MEDICAL DEVICES QUALITY SYSTEM REGULATION Statistical Techniques § 820.250 Statistical techniques. (a... statistical techniques required for establishing, controlling, and verifying the acceptability of...

  14. 21 CFR 820.250 - Statistical techniques.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Statistical techniques. 820.250 Section 820.250...) MEDICAL DEVICES QUALITY SYSTEM REGULATION Statistical Techniques § 820.250 Statistical techniques. (a... statistical techniques required for establishing, controlling, and verifying the acceptability of...

  15. 21 CFR 820.250 - Statistical techniques.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Statistical techniques. 820.250 Section 820.250...) MEDICAL DEVICES QUALITY SYSTEM REGULATION Statistical Techniques § 820.250 Statistical techniques. (a... statistical techniques required for establishing, controlling, and verifying the acceptability of...

  16. 21 CFR 820.250 - Statistical techniques.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Statistical techniques. 820.250 Section 820.250...) MEDICAL DEVICES QUALITY SYSTEM REGULATION Statistical Techniques § 820.250 Statistical techniques. (a... statistical techniques required for establishing, controlling, and verifying the acceptability of...

  17. Minimally invasive technique for curettage of chondroblastoma using endoscopic technique.

    PubMed

    Errani, C; Traina, F; Chehrassan, M; Donati, D; Faldini, C

    2014-11-01

    Chondroblastoma is a rare benign bone tumor. The treatment for chondroblastoma usually consists of curettage of the lesion and packing the tumor cavity with bone grafts or bone cement. However, chondroblastomas are known to recur in 10% to 20% of cases after excision, possibly because the incomplete removal of pathological tissue at surgery. We present a case of chondroblastoma in the distal femur treated by endoscopic curettage, which allowed a complete resection of tumor tissue and a minimal damage of the bone. The patient had relief of symptoms, rapid function restoration and no local recurrence. Endoscopic curettage is a promising new treatment for chondroblastoma. In fact, the extra-articular technique enters the tumor cavity via a tunnel drilled through the medullary canal, allowing to visualize possible residual tumor tissue or defects of the articular surface, without violating the joint and without taking away a much bigger cortical window.

  18. Minimally invasive technique for curettage of chondroblastoma using endoscopic technique.

    PubMed

    Errani, C; Traina, F; Chehrassan, M; Donati, D; Faldini, C

    2014-11-01

    Chondroblastoma is a rare benign bone tumor. The treatment for chondroblastoma usually consists of curettage of the lesion and packing the tumor cavity with bone grafts or bone cement. However, chondroblastomas are known to recur in 10% to 20% of cases after excision, possibly because the incomplete removal of pathological tissue at surgery. We present a case of chondroblastoma in the distal femur treated by endoscopic curettage, which allowed a complete resection of tumor tissue and a minimal damage of the bone. The patient had relief of symptoms, rapid function restoration and no local recurrence. Endoscopic curettage is a promising new treatment for chondroblastoma. In fact, the extra-articular technique enters the tumor cavity via a tunnel drilled through the medullary canal, allowing to visualize possible residual tumor tissue or defects of the articular surface, without violating the joint and without taking away a much bigger cortical window. PMID:25491613

  19. A Comparative of business process modelling techniques

    NASA Astrophysics Data System (ADS)

    Tangkawarow, I. R. H. T.; Waworuntu, J.

    2016-04-01

    In this era, there is a lot of business process modeling techniques. This article is the research about differences of business process modeling techniques. For each technique will explain about the definition and the structure. This paper presents a comparative analysis of some popular business process modelling techniques. The comparative framework is based on 2 criteria: notation and how it works when implemented in Somerleyton Animal Park. Each technique will end with the advantages and disadvantages. The final conclusion will give recommend of business process modeling techniques that easy to use and serve the basis for evaluating further modelling techniques.

  20. SHADOW: a new welding technique

    NASA Astrophysics Data System (ADS)

    Kramer, Thorsten; Olowinsky, Alexander M.; Durand, Friedrich

    2002-06-01

    The new welding technique 'SHADOW ' is introduced. SHADOW means the use of a single pulse to generate a quasi continuous weld of several millimeters in length. HET processing time is defined by the pulse duration of the pulsed laser. At present, a state-of-the-art laser is capable of a maximum pulse duration of 20 ms. The variation of the laser power depend on time is a vital capability of the pulsed laser to adapt the energy deposition into the workpiece. Laser beam welds of several watch components were successfully performed. Similar metals like crowns and axes made out of stainless steel have been welded using pulsed laser radiation. Applying a series of about 130 single pulses for the crown-axis combination the total energy accumulates to 19.5 J. The use of the SHADOW welding technique reduces the energy to 2.5 J. While welding dissimilar metals like stainless steel and bras, the SHADOW welding reduces drastically the contamination as well as the distortion. Laser beam welding of copper has a low process reliability due to the high reflection and the high thermal conductivity. SHADOW welds of 3.6 mm length were performed on 250 micrometers thick copper plates with very high reproducibility. As a result, a pilot plant for laser beam welding of copper plates has been set up. The work to be presented has partly been funded by the European Commission in a project under the contract BRPR-CT-0634.

  1. A standardized block fabrication technique

    SciTech Connect

    Famiglietti, R.; Noriega, B.; Sanders, R. )

    1990-01-01

    The accuracy of delivered dose is a primary goal in every radiation therapy department. Improved imaging techniques now enable the radiation therapist to define more precisely the area of interest, which helps the sparing of normal surrounding tissue. Tray-mounted customized blocks are routinely used to define this treatment portal accurately and reproducibly. However, the level of accuracy is dependent on the block fabrication technique and the skill of the block cutter. We at Moffitt Cancer Center have standardized our system in a way that minimizes some of the human errors, while keeping the procedure fast and accurate. This system uses a tray template that simulates our blocking trays. The function of this tray is to position the styrofoam (and therefore the cerrobend block) on the tray in such a way as to insure proper alignment with the treatment machine. We also feel this improves upon some common designs using random holes or hole patterns, which may interfere with the treatment area. This system is not overly sophisticated and can be easily implemented in most radiation therapy departments.

  2. Advanced techniques in abdominal surgery.

    PubMed Central

    Monson, J R

    1993-01-01

    Almost every abdominal organ is now amenable to laparoscopic surgery. Laparoscopic appendicectomy is a routine procedure which also permits identification of other conditions initially confused with an inflamed appendix. However, assessment of appendiceal inflammation is more difficult. Almost all colonic procedures can be performed laparoscopically, at least partly, though resection for colonic cancer is still controversial. For simple patch repair of perforated duodenal ulcers laparoscopy is ideal, and inguinal groin hernia can be repaired satisfactorily with a patch of synthetic mesh. Many upper abdominal procedures, however, still take more time than the open operations. These techniques reduce postoperative pain and the incidence of wound infections and allow a much earlier return to normal activity compared with open surgery. They have also brought new disciplines: surgeons must learn different hand-eye coordination, meticulous haemostasis is needed to maintain picture quality, and delivery of specimens may be problematic. The widespread introduction of laparoscopic techniques has emphasised the need for adequate training (operations that were straight-forward open procedures may require considerable laparoscopic expertise) and has raised questions about trainee surgeons acquiring adequate experience of open procedures. Images FIG 9 p1347-a p1347-b p1349-a p1350-a p1350-b PMID:8257893

  3. Model building techniques for analysis.

    SciTech Connect

    Walther, Howard P.; McDaniel, Karen Lynn; Keener, Donald; Cordova, Theresa Elena; Henry, Ronald C.; Brooks, Sean; Martin, Wilbur D.

    2009-09-01

    The practice of mechanical engineering for product development has evolved into a complex activity that requires a team of specialists for success. Sandia National Laboratories (SNL) has product engineers, mechanical designers, design engineers, manufacturing engineers, mechanical analysts and experimentalists, qualification engineers, and others that contribute through product realization teams to develop new mechanical hardware. The goal of SNL's Design Group is to change product development by enabling design teams to collaborate within a virtual model-based environment whereby analysis is used to guide design decisions. Computer-aided design (CAD) models using PTC's Pro/ENGINEER software tools are heavily relied upon in the product definition stage of parts and assemblies at SNL. The three-dimensional CAD solid model acts as the design solid model that is filled with all of the detailed design definition needed to manufacture the parts. Analysis is an important part of the product development process. The CAD design solid model (DSM) is the foundation for the creation of the analysis solid model (ASM). Creating an ASM from the DSM currently is a time-consuming effort; the turnaround time for results of a design needs to be decreased to have an impact on the overall product development. This effort can be decreased immensely through simple Pro/ENGINEER modeling techniques that summarize to the method features are created in a part model. This document contains recommended modeling techniques that increase the efficiency of the creation of the ASM from the DSM.

  4. Compensation Techniques in Accelerator Physics

    SciTech Connect

    Sayed, Hisham Kamal

    2011-05-01

    Accelerator physics is one of the most diverse multidisciplinary fields of physics, wherein the dynamics of particle beams is studied. It takes more than the understanding of basic electromagnetic interactions to be able to predict the beam dynamics, and to be able to develop new techniques to produce, maintain, and deliver high quality beams for different applications. In this work, some basic theory regarding particle beam dynamics in accelerators will be presented. This basic theory, along with applying state of the art techniques in beam dynamics will be used in this dissertation to study and solve accelerator physics problems. Two problems involving compensation are studied in the context of the MEIC (Medium Energy Electron Ion Collider) project at Jefferson Laboratory. Several chromaticity (the energy dependence of the particle tune) compensation methods are evaluated numerically and deployed in a figure eight ring designed for the electrons in the collider. Furthermore, transverse coupling optics have been developed to compensate the coupling introduced by the spin rotators in the MEIC electron ring design.

  5. Repositioning of Covered Stents: The Grip Technique

    SciTech Connect

    Kirby, John Martin; Guo Xiaofeng; Midia, Mehran

    2011-06-15

    Introduction: Retrieval and repositioning of a stent deployed beyond its intended target region may be a difficult technical challenge. Materials and Methods: A balloon-mounted snare technique, a variant of the coaxial loop snare technique, is described. Results: The technique is described for the repositioning of a covered transjugular intrahepatic portosystemic shunt stent and a covered biliary stent. Conclusion: The balloon-mounted snare technique is a useful technique for retrieval of migrated stents.

  6. Balloon-based interferometric techniques

    NASA Technical Reports Server (NTRS)

    Rees, David

    1985-01-01

    A balloon-borne triple-etalon Fabry-Perot Interferometer, observing the Doppler shifts of absorption lines caused by molecular oxygen and water vapor in the far red/near infrared spectrum of backscattered sunlight, has been used to evaluate a passive spaceborne remote sensing technique for measuring winds in the troposphere and stratosphere. There have been two successful high altitude balloon flights of the prototype UCL instrument from the National Scientific Balloon Facility at Palestine, TE (May 80, Oct. 83). The results from these flights have demonstrated that an interferometer with adequate resolution, stability and sensitivity can be built. The wind data are of comparable quality to those obtained from operational techniques (balloon and rocket sonde, cloud-top drift analysis, and from the gradient wind analysis of satellite radiance measurements). However, the interferometric data can provide a regular global grid, over a height range from 5 to 50 km in regions of clear air. Between the middle troposphere (5 km) and the upper stratosphere (40 to 50 km), an optimized instrument can make wind measurements over the daylit hemisphere with an accuracy of about 3 to 5 m/sec (2 sigma). It is possible to obtain full height profiles between altitudes of 5 and 50 km, with 4 km height resolution, and a spatial resolution of about 200 km, along the orbit track. Below an altitude of about 10 km, Fraunhofer lines of solar origin are possible targets of the Doppler wind analysis. Above an altitude of 50 km, the weakness of the backscattered solar spectrum (decreasing air density) is coupled with the low absorption crosssection of all atmospheric species in the spectral region up to 800 nm (where imaging photon detectors can be used), causing the along-the-track resolution (or error) to increase beyond values useful for operational purposes. Within the region of optimum performance (5 to 50 km), however, the technique is a valuable potential complement to existing wind

  7. Brain Neuromodulation Techniques: A Review.

    PubMed

    Lewis, Philip M; Thomson, Richard H; Rosenfeld, Jeffrey V; Fitzgerald, Paul B

    2016-08-01

    The modulation of brain function via the application of weak direct current was first observed directly in the early 19th century. In the past 3 decades, transcranial magnetic stimulation and deep brain stimulation have undergone clinical translation, offering alternatives to pharmacological treatment of neurological and neuropsychiatric disorders. Further development of novel neuromodulation techniques employing ultrasound, micro-scale magnetic fields and optogenetics is being propelled by a rapidly improving understanding of the clinical and experimental applications of artificially stimulating or depressing brain activity in human health and disease. With the current rapid growth in neuromodulation technologies and applications, it is timely to review the genesis of the field and the current state of the art in this area. PMID:27130839

  8. Subranging technique using superconducting technology

    DOEpatents

    Gupta, Deepnarayan

    2003-01-01

    Subranging techniques using "digital SQUIDs" are used to design systems with large dynamic range, high resolution and large bandwidth. Analog-to-digital converters (ADCs) embodying the invention include a first SQUID based "coarse" resolution circuit and a second SQUID based "fine" resolution circuit to convert an analog input signal into "coarse" and "fine" digital signals for subsequent processing. In one embodiment, an ADC includes circuitry for supplying an analog input signal to an input coil having at least a first inductive section and a second inductive section. A first superconducting quantum interference device (SQUID) is coupled to the first inductive section and a second SQUID is coupled to the second inductive section. The first SQUID is designed to produce "coarse" (large amplitude, low resolution) output signals and the second SQUID is designed to produce "fine" (low amplitude, high resolution) output signals in response to the analog input signals.

  9. Ancient techniques for new materials

    NASA Technical Reports Server (NTRS)

    2000-01-01

    NASA is looking to biological techniques that are millions of years old to help it develop new materials and technologies for the 21st century. Sponsored by NASA, Jeffrey Brinker of the University of New Mexico is studying how multiple elements can assemble themselves into a composite material that is clear, tough, and impermeable. His research is based on the model of how an abalone builds the nacre, also called mother-of-pearl, inside its shell. The mollusk layers bricks of calcium carbonate (the main ingredient in classroom chalk) and mortar of biopolymer to form a new material (top and bottom left) that is twice as hard and 1,000 times as tough as either of the original building materials.

  10. Surgical skin-marking techniques.

    PubMed

    Granick, M S; Heckler, F R; Jones, E W

    1987-04-01

    Surgical skin-marking inks and dyes are in everyday use for designing and planning incisions in plastic and reconstructive surgery. We have traced the historical development of surgical skin-marking techniques from ancient times to the present. The biochemical characteristics of the commonly used marking agents are discussed. A three-part experiment utilizing a pig model was carried out to test the tissue inflammatory response to the various dyes and inks when used intradermally as tattoos, the persistence of such tattoos, and the ease of skin erasure for each of eight stains. Methylene blue and gentian violet are recommended as the best all-purpose marking agents. The use of proprietary inks is discouraged.

  11. Ancient techniques for new materials

    NASA Technical Reports Server (NTRS)

    2000-01-01

    NASA is looking to biological techniques that are millions of years old to help it develop new materials and nanotechnology for the 21st century. Sponsored by NASA, Jerzy Bernholc, a principal investigator in the microgravity materials science program and a physics professor at North Carolina State University, Bernholc works with very large-scale computations to model carbon molecules as they assemble themselves to form nanotubes. The strongest confirmed material known, nanotubes are much stronger than graphite, a more common material made of carbon, and weigh six times less than steel. Nanotubes have potential uses such as strain gauges, advanced electronic devices, amd batteries. The strength, light weight, and conductive qualities of nanotubes, shown in light blue in this computed electron distribution, make them excellent components of nanoscale devices. One way to conduct electricity to such devices is through contact with aluminum, shown in dark blue.

  12. Techniques De Visualisation En Aerodynamique

    NASA Astrophysics Data System (ADS)

    Veret, Claude M.

    1985-02-01

    During the tests in wind tunnel, flow visualization techniques offer to the aerodynamicists general views of the whole or part of flows they are studying. Even when the image observation only provides qualitative informations, the high density of these informations leads to a synthetic interpretation of the very complex physical phenomena which take place in the course of the interaction between a flow and a solid in relative motion. The variety of these techniques arises from the problem diversity according to the fluid relative velocity and to the solid wall proximity. On the wall, informations are obtained by examination of the flows of more or less viscous, colored or not, liquid spread on the surface, or still thin tufts motion. Out of the wall, the techniques to be used are different according that the external flow velocity is more or less fast as that of the sound in this medium. In subsonic flow, the air is seeded with tracers in the shape of small solid or liquid particles. Observed individualy or in groups, the particle motion informs on this of the surrounding air. Images are obtained thanks to the particle scattering properties regarding the illumination light. Changes in the illuminating conditions (total illumination or by a light sheet) allow to show particular features such as vortices, separation and recirculating zones, ..In the supersonic domain, new physical phenomena appear, providing rough or progressive changes of the gas density (particularly, shock wave apparition). These density variations involve propagation light perturbations (phase changes in a light wave or light ray de-viations in a beam). It is the domain where techniques such as interferometry, schlieren and shadowgraphy are developed. They provide not only qualitative visualizations, but, in certain cases, such as two-dimensional or axisymetrical flows, they allow density distribution determinations. Some phenomena are very brief (detonation wave propagation) or evolve fast

  13. Techniques for shuttle trajectory optimization

    NASA Technical Reports Server (NTRS)

    Edge, E. R.; Shieh, C. J.; Powers, W. F.

    1973-01-01

    The application of recently developed function-space Davidon-type techniques to the shuttle ascent trajectory optimization problem is discussed along with an investigation of the recently developed PRAXIS algorithm for parameter optimization. At the outset of this analysis, the major deficiency of the function-space algorithms was their potential storage problems. Since most previous analyses of the methods were with relatively low-dimension problems, no storage problems were encountered. However, in shuttle trajectory optimization, storage is a problem, and this problem was handled efficiently. Topics discussed include: the shuttle ascent model and the development of the particular optimization equations; the function-space algorithms; the operation of the algorithm and typical simulations; variable final-time problem considerations; and a modification of Powell's algorithm.

  14. [Surgical techniques of organ transplants].

    PubMed

    Froněk, Jiří

    2015-01-01

    The list of surgical procedures of solid organ transplantations appears very interesting and colorful, even with overlap among techniques. Liver transplantation is a life-saving procedure in a majority of cases, the liver can be transplanted as a full or partial graft. The liver graft can be split for two recipients; it can also be reduced for a small recipient if splitting is not indicated. Kidney transplantation is the most common solid organ transplant procedure, the majority of kidney grafts come from brain-dead donors whereas the number of live donor transplants is increasing, also thanks to paired donation and blood group incompatible transplantation methods. The small bowel and multivisceral transplantation are rare procedures; they serve selected patients with short bowel syndrome, some patients with retroperitoneal tumors or with extensive visceral thrombosis. Solid organ transplants are well established treatment methods with good and proven outcomes. A majority of patients can return to a normal life after their transplants.

  15. Kinetic activation-relaxation technique.

    PubMed

    Béland, Laurent Karim; Brommer, Peter; El-Mellouhi, Fedwa; Joly, Jean-François; Mousseau, Normand

    2011-10-01

    We present a detailed description of the kinetic activation-relaxation technique (k-ART), an off-lattice, self-learning kinetic Monte Carlo (KMC) algorithm with on-the-fly event search. Combining a topological classification for local environments and event generation with ART nouveau, an efficient unbiased sampling method for finding transition states, k-ART can be applied to complex materials with atoms in off-lattice positions or with elastic deformations that cannot be handled with standard KMC approaches. In addition to presenting the various elements of the algorithm, we demonstrate the general character of k-ART by applying the algorithm to three challenging systems: self-defect annihilation in c-Si (crystalline silicon), self-interstitial diffusion in Fe, and structural relaxation in a-Si (amorphous silicon).

  16. Techniques for multilayer channel routing

    NASA Astrophysics Data System (ADS)

    Braun, Douglas; Burns, Jeffrey L.; Romeo, Fabio; Sangiovanni-Vincentelli, Alberto; Mayaram, Kartikeya

    1988-06-01

    The techniques described have been implemented in a multilayer channel router called Chameleon. Chameleon consists of two stages: a partitioner and a detailed router. The partitioner divides the problem into two-layer and three-layer subproblems such that global channel area is minimized. The detailed router then implements the connections using generalizations of the algorithms used in YACR2. In particular, a three-dimensional maze router is used for the vertical connections; this methodology is effective even when cycle constraints are present. Chameleon has produced optimal results on a wide range of industrial and academic examples for a variety of layer and pitch combinations, and can handle a variety of technology constraints.

  17. [Surgical techniques of organ transplants].

    PubMed

    Froněk, Jiří

    2015-01-01

    The list of surgical procedures of solid organ transplantations appears very interesting and colorful, even with overlap among techniques. Liver transplantation is a life-saving procedure in a majority of cases, the liver can be transplanted as a full or partial graft. The liver graft can be split for two recipients; it can also be reduced for a small recipient if splitting is not indicated. Kidney transplantation is the most common solid organ transplant procedure, the majority of kidney grafts come from brain-dead donors whereas the number of live donor transplants is increasing, also thanks to paired donation and blood group incompatible transplantation methods. The small bowel and multivisceral transplantation are rare procedures; they serve selected patients with short bowel syndrome, some patients with retroperitoneal tumors or with extensive visceral thrombosis. Solid organ transplants are well established treatment methods with good and proven outcomes. A majority of patients can return to a normal life after their transplants. PMID:26585110

  18. Brain Neuromodulation Techniques: A Review.

    PubMed

    Lewis, Philip M; Thomson, Richard H; Rosenfeld, Jeffrey V; Fitzgerald, Paul B

    2016-08-01

    The modulation of brain function via the application of weak direct current was first observed directly in the early 19th century. In the past 3 decades, transcranial magnetic stimulation and deep brain stimulation have undergone clinical translation, offering alternatives to pharmacological treatment of neurological and neuropsychiatric disorders. Further development of novel neuromodulation techniques employing ultrasound, micro-scale magnetic fields and optogenetics is being propelled by a rapidly improving understanding of the clinical and experimental applications of artificially stimulating or depressing brain activity in human health and disease. With the current rapid growth in neuromodulation technologies and applications, it is timely to review the genesis of the field and the current state of the art in this area.

  19. Ancient techniques for new materials

    NASA Technical Reports Server (NTRS)

    2000-01-01

    NASA is looking to biological techniques that are millions of years old to help it develop new materials and technologies for the 21st century. Sponsored by NASA, Jeffrey Brinker of the University of New Mexico is studying how multiple elements can assemble themselves into a composite material that is clear, tough, and impermeable. His research is based on the model of how an abalone builds the nacre, also called mother-of-pearl, inside its shell. Strong thin coatings, or lamellae, in Brinker's research are formed when objects are dip-coated. Evaporation drives the self-assembly of molecular aggregates (micelles) of surfactant, soluble silica, and organic monomers and their further self-organization into layered organic and inorganic assemblies.

  20. Ancient techniques for new materials

    NASA Technical Reports Server (NTRS)

    2000-01-01

    NASA is looking to biological techniques that are millions of years old to help it develop new materials and technologies for the 21st century. Sponsored by NASA, Viola Vogel, director of Washington University's Center for Nanotechnology and a principal investigator for the microgravity biotechnology program, is researching a monorail on a nanoscale to learn how to control translational motion of motor proteins in nonbiological environments in order to transport cargo between user-specified locations. Shear-deposition of Teflon on glass (top) is used in Viola Vogel's lab to create a nanogrooved surface. The topography controls the path that microtubules take as they shuttle nano-sized cargo between user-defined destinations.