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Sample records for antiorthostatic suspension stimulates

  1. Antiorthostatic suspension stimulates profiles of macrophage activation in mice

    NASA Technical Reports Server (NTRS)

    Miller, E. S.; Bates, R. A.; Koebel, D. A.; Sonnenfeld, G.

    1999-01-01

    The antiorthostatic suspension model simulates certain physiological effects of spaceflight. We have previously reported BDF1 mice suspended by the tail in the antiorthostatic orientation for 4 days express high levels of resistance to virulent Listeria monocytogenesinfection. In the present study, we examined whether the increased resistance to this organism correlates with profiles of macrophage activation, given the role of the macrophage in killing this pathogen in vivo. We infected BDF1 mice with a lethal dose of virulent L. monocytogenes on day 4 of antiorthostatic suspension and 24 h later constructed profiles of macrophage activation. Viable listeria could not be detected in mice suspended in the antiorthostatic orientation 24 h after infection. Flow cytometric analysis revealed the numbers of granulocytes and mononuclear phagocytes in the spleen of infected mice were not significantly altered as a result of antiorthostatic suspension. Splenocytes from antiorthostatically suspended infected mice produced increased titers of IL-1. Serum levels of neopterin, a nucleotide metabolite secreted by activated macrophages, were enhanced in mice infected during antiorthostatic suspension, but not in antiorthostatically suspended naive mice. Splenic macrophages from mice infected on day 4 of suspension produced enhanced levels of lysozyme. In contrast to the results from antiorthostatically suspended infected mice, macrophages from antiorthostatically suspended uninfected mice did not express enhanced bactericidal activities. The collective results indicate that antiorthostatic suspension can stimulate profiles of macrophage activation which correlate with increased resistance to infection by certain classes of pathogenic bacteria.

  2. Antiorthostatic suspension stimulates profiles of macrophage activation in mice

    NASA Technical Reports Server (NTRS)

    Miller, E. S.; Bates, R. A.; Koebel, D. A.; Sonnenfeld, G.

    1999-01-01

    The antiorthostatic suspension model simulates certain physiological effects of spaceflight. We have previously reported BDF1 mice suspended by the tail in the antiorthostatic orientation for 4 days express high levels of resistance to virulent Listeria monocytogenesinfection. In the present study, we examined whether the increased resistance to this organism correlates with profiles of macrophage activation, given the role of the macrophage in killing this pathogen in vivo. We infected BDF1 mice with a lethal dose of virulent L. monocytogenes on day 4 of antiorthostatic suspension and 24 h later constructed profiles of macrophage activation. Viable listeria could not be detected in mice suspended in the antiorthostatic orientation 24 h after infection. Flow cytometric analysis revealed the numbers of granulocytes and mononuclear phagocytes in the spleen of infected mice were not significantly altered as a result of antiorthostatic suspension. Splenocytes from antiorthostatically suspended infected mice produced increased titers of IL-1. Serum levels of neopterin, a nucleotide metabolite secreted by activated macrophages, were enhanced in mice infected during antiorthostatic suspension, but not in antiorthostatically suspended naive mice. Splenic macrophages from mice infected on day 4 of suspension produced enhanced levels of lysozyme. In contrast to the results from antiorthostatically suspended infected mice, macrophages from antiorthostatically suspended uninfected mice did not express enhanced bactericidal activities. The collective results indicate that antiorthostatic suspension can stimulate profiles of macrophage activation which correlate with increased resistance to infection by certain classes of pathogenic bacteria.

  3. Test of the antiorthostatic suspension model on mice - Effects on the inflammatory cell response

    NASA Technical Reports Server (NTRS)

    Rosenkrans, Charles F., Jr.; Chapes, Stephen K.; Fleming, Sherry D.

    1990-01-01

    The antiorthostatic suspension model was tested for use as a 1G model to study the effects of factors that will be encountered during space travel on inflammation. No differences were found in inflammatory cells induced in antiorthostatically suspended mice. However, the superoxide response (used for oxidative killing of bacteria such as S. aureus) was impaired in antiorthostatically oriented mice compared to control mice. Elevated corticosterone levels were found in antiorthostatically suspended mice, indicating that stress may be a factor in the model. If the stress factor of the model correlates with the physiological stress of space flight, antiorthostatic suspension may be an acceptable model for studying inflammatory responses in mice.

  4. Test of the antiorthostatic suspension model on mice - Effects on the inflammatory cell response

    NASA Technical Reports Server (NTRS)

    Rosenkrans, Charles F., Jr.; Chapes, Stephen K.; Fleming, Sherry D.

    1990-01-01

    The antiorthostatic suspension model was tested for use as a 1G model to study the effects of factors that will be encountered during space travel on inflammation. No differences were found in inflammatory cells induced in antiorthostatically suspended mice. However, the superoxide response (used for oxidative killing of bacteria such as S. aureus) was impaired in antiorthostatically oriented mice compared to control mice. Elevated corticosterone levels were found in antiorthostatically suspended mice, indicating that stress may be a factor in the model. If the stress factor of the model correlates with the physiological stress of space flight, antiorthostatic suspension may be an acceptable model for studying inflammatory responses in mice.

  5. Antiorthostatic suspension as a model for the effects of spaceflight on the immune system

    NASA Technical Reports Server (NTRS)

    Chapes, S. K.; Mastro, A. M.; Sonnenfeld, G.; Berry, W. D.

    1993-01-01

    We describe the use and appropriateness of antiorthostatic suspension in immunological investigations. This manuscript describes the model and discusses how well data obtained by using the model correlate with spaceflight data. This review concludes with some suggestions for future experiments using antiorthostatic suspension.

  6. Influence of antiorthostatic suspension on resistance to murine Listeria monocytogenes infection

    NASA Technical Reports Server (NTRS)

    Miller, E. S.; Sonnenfeld, G.

    1994-01-01

    The present study was designed to evaluate the influence of antiorthostatic suspension, a ground-based modeling system employed to simulate certain aspects of weightlessness that occur during space flight, on the capacity of mice to resist infection with the facultative intracellular bacterial pathogen Listeria monocytogenes. Female BDF1 mice were suspended by the tail in the orthostatic or antiorthostatic position and were infected with a sublethal dose of virulent L. monocytogenes at various times during the suspension. It was found that suspension did not influence the kinetics of bacterial growth in vivo if the infection was started concurrently with the suspension. However, mice that were antiorthostatically suspended 2, 4, or 7 days before the onset of infection exhibited an enhanced capacity to eliminate the challenge infection. Suspending mice on day 2 of the infection did not alter the kinetics of bacterial growth. Finally, the enhancement of resistance to the primary Listeria infection was accompanied by failure of the mice to generate long-term protective immunological memory to the challenge organism. Collectively, these results indicate that the stress of antiorthostatic suspension can influence the capacity of mice to resist bacterial infection.

  7. Influence of antiorthostatic suspension on resistance to murine Listeria monocytogenes infection

    NASA Technical Reports Server (NTRS)

    Miller, E. S.; Sonnenfeld, G.

    1994-01-01

    The present study was designed to evaluate the influence of antiorthostatic suspension, a ground-based modeling system employed to simulate certain aspects of weightlessness that occur during space flight, on the capacity of mice to resist infection with the facultative intracellular bacterial pathogen Listeria monocytogenes. Female BDF1 mice were suspended by the tail in the orthostatic or antiorthostatic position and were infected with a sublethal dose of virulent L. monocytogenes at various times during the suspension. It was found that suspension did not influence the kinetics of bacterial growth in vivo if the infection was started concurrently with the suspension. However, mice that were antiorthostatically suspended 2, 4, or 7 days before the onset of infection exhibited an enhanced capacity to eliminate the challenge infection. Suspending mice on day 2 of the infection did not alter the kinetics of bacterial growth. Finally, the enhancement of resistance to the primary Listeria infection was accompanied by failure of the mice to generate long-term protective immunological memory to the challenge organism. Collectively, these results indicate that the stress of antiorthostatic suspension can influence the capacity of mice to resist bacterial infection.

  8. Effect of antiorthostatic suspension on interferon-alpha/beta production by the mouse (41939)

    NASA Technical Reports Server (NTRS)

    Rose, Andrea; Steffen, Joseph M.; Musacchia, X. J.; Sonnenfeld, Gerald; Mandel, Adrian D.

    1984-01-01

    Mice were suspended in a model that simulates the weightlessness that occurs during prolonged space flight. After one and two weeks of suspension in an antiorthostatic (head-down tilt) position, the mice were challenged with polyriboinosinic-polyribocytidylic acid to induce interferon-alpha/beta. Interferon production was severely reduced in mice that had been suspended. When mice were allowed to recover in cages for a week following removal from suspension, they recovered their full interferon-production capacity. Mice suspended in an orthostatic (horizontal) position did not have their interferon production capabilities affected, which indicates that stress per se was not a major component in the effects of antiorthostatic suspension on interferon induction.

  9. A suspension model for hypokinetic/hypodynamic and antiorthostatic responses in the mouse

    NASA Technical Reports Server (NTRS)

    Steffen, J. M.; Dombrowski, M. J.; Musacchia, X. J.; Sonnenfeld, G.; Mandel, A. D.; Robb, R.

    1984-01-01

    Hypokinetic/hypodynamic and antiorthostatic responses to weightlessness and bedrest were simulated in mice using a suspension technique. Animals were suspended for 1 or 2 weeks in an antiorthostatic posture and positioned to permit freedom of movement but eliminate load bearing by the hindlimbs. Suspended mice exhibited reduced food and water intakes and a rapid 10 percent decrease in body weight to a level which was maintained for the remainder of the suspension period. Diuresis was evident in suspended mice, but the natriuresis and kaliuresis previously observed in the suspended rat were not evident. Differential hindlimb muscle atrophy and increased excretion of urea and ammonia were also noted in suspended mice. Postsuspension recovery studies indicated that the recovery process was highly effective. These results document specific responses in the mouse and similarities in the responses of mice and rats to suspension. These studies expand the utility of the suspension model and suggest that the mouse may be useful in future studies simulating both weightlessness and bedrest.

  10. A suspension model for hypokinetic/hypodynamic and antiorthostatic responses in the mouse

    NASA Technical Reports Server (NTRS)

    Steffen, J. M.; Dombrowski, M. J.; Musacchia, X. J.; Sonnenfeld, G.; Mandel, A. D.; Robb, R.

    1984-01-01

    Hypokinetic/hypodynamic and antiorthostatic responses to weightlessness and bedrest were simulated in mice using a suspension technique. Animals were suspended for 1 or 2 weeks in an antiorthostatic posture and positioned to permit freedom of movement but eliminate load bearing by the hindlimbs. Suspended mice exhibited reduced food and water intakes and a rapid 10 percent decrease in body weight to a level which was maintained for the remainder of the suspension period. Diuresis was evident in suspended mice, but the natriuresis and kaliuresis previously observed in the suspended rat were not evident. Differential hindlimb muscle atrophy and increased excretion of urea and ammonia were also noted in suspended mice. Postsuspension recovery studies indicated that the recovery process was highly effective. These results document specific responses in the mouse and similarities in the responses of mice and rats to suspension. These studies expand the utility of the suspension model and suggest that the mouse may be useful in future studies simulating both weightlessness and bedrest.

  11. Antiorthostatic suspension for 14 days does not diminish the oxidative response of neutrophils in mice

    NASA Technical Reports Server (NTRS)

    Smolen, J. E.; Fossett, M. C.; Joe, Y.; Prince, J. E.; Priest, E.; Kanwar, S.; Smith, C. W.

    2000-01-01

    The effects of long-term spaceflight on inflammatory responses have not been well-studied in either humans or animals. It is thus important to determine if the functions of immune and inflammatory cells are altered in models of spaceflight. One such animal model is antiorthostatic suspension (AOS), in which the experimental animal is subjected to a head-down tilt that mimics both the stress and the cephalad fluid shift experienced in spaceflight. A previous study reported that the peritoneal neutrophils from mice experiencing AOS generated less superoxide than unsuspended controls. We expanded on this study using several different stimuli and measuring the oxidative response of murine neutrophils in a variety of ways. These responses included the rate, lag period, and dose/response characteristics for superoxide generation, FACS analysis with dihydrodichlorofluorescein as a substrate, and a chemiluminescence response with luminol as a substrate. We also examined phagocytosis of three different microorganisms. While some effects of orthostatic suspension (attributable to the stress of the apparatus) were observed, no clear effects of AOS on oxidative function of the peritoneal neutrophils were seen.

  12. Antiorthostatic suspension for 14 days does not diminish the oxidative response of neutrophils in mice

    NASA Technical Reports Server (NTRS)

    Smolen, J. E.; Fossett, M. C.; Joe, Y.; Prince, J. E.; Priest, E.; Kanwar, S.; Smith, C. W.

    2000-01-01

    The effects of long-term spaceflight on inflammatory responses have not been well-studied in either humans or animals. It is thus important to determine if the functions of immune and inflammatory cells are altered in models of spaceflight. One such animal model is antiorthostatic suspension (AOS), in which the experimental animal is subjected to a head-down tilt that mimics both the stress and the cephalad fluid shift experienced in spaceflight. A previous study reported that the peritoneal neutrophils from mice experiencing AOS generated less superoxide than unsuspended controls. We expanded on this study using several different stimuli and measuring the oxidative response of murine neutrophils in a variety of ways. These responses included the rate, lag period, and dose/response characteristics for superoxide generation, FACS analysis with dihydrodichlorofluorescein as a substrate, and a chemiluminescence response with luminol as a substrate. We also examined phagocytosis of three different microorganisms. While some effects of orthostatic suspension (attributable to the stress of the apparatus) were observed, no clear effects of AOS on oxidative function of the peritoneal neutrophils were seen.

  13. Enhancement of viral pathogenesis in mice maintained in an antiorthostatic suspension model - Coordination with effects on interferon production

    NASA Technical Reports Server (NTRS)

    Gould, C. L.; Sonnenfeld, G.

    1987-01-01

    Both rodents and men returning from spaceflight have exhibited alterations in immune responses and, in particular, interferon production. This work utilizes a model for antiorthostatic (20-deg head-down tilt), hypokinetic, hypodynamic suspension of mice that simulates some aspects of weightlessness. Female Swiss/Webster mice that are normally resistant to infection with the D variant of encephalomyocarditis virus showed a marked increase in susceptibility to infection when suspended. This correlated with a drop in interferom production. Control, orthostatically suspended mice (no tilt) showed no increase in susceptibility to the virus.

  14. Effect of Long-Term Antiorthostatic Suspension in a Murine Model of Acute Lung Injury

    PubMed Central

    Jang, Tae Young; Jung, Ah-Yeoun; Kim, Young Hyo

    2016-01-01

    Objectives Antiorthostatic suspension (AOS) is ground-based model of simulated microgravity. There is still no study about the effect of long-term microgravity on the clinical course of acute lung injury. We evaluated the effect of simulated microgravity using AOS in a murine model of acute lung injury by lipopolysaccharide (LPS). Methods Thirty BALB/c mice were used. During 4 weeks, mice were equally allocated to control (free movement), restraint (tail suspended, but hindlimbs not unloaded), and AOS group (hindlimb unloaded). After then, mice got intranasal challenge with LPS (20 mg/kg, 50 μL). We measured: weight gain before and after AOS, the number of inflammatory cells and titers of cytokines (interleukin [IL]-1β, IL-6, IL-10, tumor necrosis factor-α, and interferon-γ) in bronchoalveolar lavage (BAL) fluid, titer of myeloperoxidase (MPO) in serum and lung homogenate, and histopathologic examination of lung tissue. Results AOS group had significant weight loss compared to control and restraint group (P<0.001). AOS group also showed significantly decreased lymphocytes (P=0.023) compared to control group. In AOS group, titer for IL-1β in BAL fluid was significantly lower than restraint group (P=0.049). Titer for serum MPO was significantly decreased in AOS group compared to restraint group (P=0.004). However, there was no significant difference of MPO titers in lung tissue between groups. Histopathologic examination of lung tissue revealed no significant difference in the degree of pulmonary infiltration between restraint and AOS group. Conclusion In spite of modest anti-inflammatory effect, prolonged AOS caused no significant change in LPS-induced pulmonary inflammation. PMID:27334509

  15. Structure and Functional Characteristics of Rat's Left Ventricle Cardiomyocytes under Antiorthostatic Suspension of Various Duration and Subsequent Reloading

    PubMed Central

    Ogneva, I. V.; Mirzoev, T. M.; Biryukov, N. S.; Veselova, O. M.; Larina, I. M.

    2012-01-01

    The goal of the research was to identify the structural and functional characteristics of the rat's left ventricle under antiorthostatic suspension within 1, 3, 7 and 14 days, and subsequent 3 and 7-day reloading after a 14-day suspension. The transversal stiffness of the cardiomyocyte has been determined by the atomic force microscopy, cell respiration—by polarography and proteins content—by Western blotting. Stiffness of the cortical cytoskeleton increases as soon as one day after the suspension and increases up to the 14th day, and starts decreasing during reloading, reaching the control level after 7 days. The stiffness of the contractile apparatus and the intensity of cell respiration also increases. The content of non-muscle isoforms of actin in the cytoplasmic fraction of proteins does not change during the whole experiment, as does not the beta-actin content in the membrane fraction. The content of gamma-actin in the membrane fraction correlates with the change in the transversal stiffness of the cortical cytoskeleton. Increased content of alpha-actinin-1 and alpha-actinin-4 in the membrane fraction of proteins during the suspension is consistent with increased gamma-actin content there. The opposite direction of change of alpha-actinin-1 and alpha-actinin-4 content suggests their involvement into the signal pathways. PMID:23093854

  16. Combined effects of antiorthostatic suspension and ionizing radiation on the behaviour and neurotransmitters changes in different brain structures of rats.

    PubMed

    Kokhan, V S; Matveeva, M I; Bazyan, A S; Kudrin, V S; Mukhametov, A; Shtemberg, A S

    2017-03-01

    Space flight factors (SFF) significantly affect the operating activity of astronauts during deep space missions. In contrast to an orbital flight, leaving the Earth's magnetic field is fraught with the dangers of exposure to ionizing radiation and more specifically, the high-energy nuclei component of galactic cosmic rays. Microgravity, just another critical non-radiation factor, significantly affects the normal functioning of the CNS. Some morphological structures of the brain, such as the prefrontal cortex and the hippocampus, that are rich in monoaminergic and acetylcholinergic neurones, are the most sensitive to the effects of ionizing radiation and non-radiation spaceflight factors (SFF). In this work we have studied the combined effects of microgravity (in antiorthostatic suspension model, AS) and irradiation (γ-ray and protons in spread-out Bragg peak) on the behaviour, cognitive abilities, and metabolism of monoamines and acetylcholine in the key structures of the rat's brain. Irradiation (as independently as combined with AS) resulted in the decrease of thigmotaxis in rats. Learning problems, caused by the malfunctioning of the working memory but not the spatial memory, were observed in response to AS as well as to the SFF in combination. Analysis of monoamines metabolism showed that the serotoninergic system was the most affected by the SFF. Concentration of acetylcholine in the hippocampus significantly increased in the groups of irradiated rats, and in the groups which were exposed to the SFF in combination, compared to the rats exposed only to AS. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Three Weeks of Anti-orthostatic Suspension had no Effect on Immune Status in a Specific-Pathogen-Free Enfvironment

    NASA Astrophysics Data System (ADS)

    Jang, Tae Young; Chang, Geun Uck; Kim, Kyu-Sung; Heo, Min-Jeong; Jung, Ah-Yeoun; Kim, Young Hyo

    2015-09-01

    Anti-Orthostatic Suspension (AOS) is a well-known murine ground-based model of simulated microgravity. However, because no commercial equipment is available for AOS in Specific-Pathogen-Free (SPF) laboratories no previous study has been conducted to examine the effect of AOS on allergic immunity. Accordingly, we developed an AOS cage suitable for SPF conditions, and evaluate its reliability and the effect of 3 weeks of AOS on immunity in a mouse model. An AOS cage were developed using stainless steel components. Fourteen female BALB/c mice were allocated to Group A (control group, n=7) or Group B (AOS, n=7). Body weights and thickness of posterior thigh muscles were measured before and after 3 weeks of AOS, and serum IgE and the titers of cytokines (IL-4, IL-5, IL-10, IL-13, and IFN- γ) in bronchoalveolar lavage (BAL) fluid were compared, as were lung histologic findings. The SPF condition was successfully maintained. No significant difference in weight gain was observed between groups A (0.9 ±1.0 g) and B (0.8 ±1.1 g, P>0.05) after the 3-week experimental period. The mean thickness of posterior thigh muscles in Group B was significantly lower than in Group A (0.7 ±0.2 versus -0.4 ±0.3 mm, P =0.001). However, group serum IgE titers, and IL-4, IL-5, IL-10, IL-13, and IFN- γ titers in BAL fluid were non-significantly different. No intergroup difference was found by histopathologic examinations of lungs. In conclusion, using AOS equipment in a SPF laboratory, immune status was not found to be significantly affected by 3 weeks AOS in healthy mice.

  18. The Effects of Rm-CSF and Ril-6 Therapy on Immunosuppressed Antiorthostatically Suspended Mice

    NASA Technical Reports Server (NTRS)

    Armstong, Jason W.; Kirby-Dobbels, Kathy; Chapes, Steven K.

    1995-01-01

    Antiorthostatically suspended mice had suppressed macrophage development in both unloaded and loaded bones, indicating a systemic effect. Bone marrow cells from those mice secreted less macrophage colony-stimulating factor (M-CSF) and interleukin-6 (IL-6) than did control mice. Because M-CSF and IL-6 are important to bone marrow macrophage maturation, we formulated the hypothesis that suppressed macrophage development occurred as a result of the depressed levels of either M-CSF or IL-6. To test the hypothesis, mice were administered recombinant M-CSF or IL-6 intraperitoneally. We showed that recombinant M-CSF therapy, but not recombinant IL-6 therapy, reversed the suppressive effects of orthostatic suspension on macrophage development. These data suggest that bone marrow cells that produce M-CSF are affected by antiorthostatic suspension and may contribute to the inhibited maturation of bone marrow macrophage progenitors.

  19. The Effects of Rm-CSF and Ril-6 Therapy on Immunosuppressed Antiorthostatically Suspended Mice

    NASA Technical Reports Server (NTRS)

    Armstong, Jason W.; Kirby-Dobbels, Kathy; Chapes, Steven K.

    1995-01-01

    Antiorthostatically suspended mice had suppressed macrophage development in both unloaded and loaded bones, indicating a systemic effect. Bone marrow cells from those mice secreted less macrophage colony-stimulating factor (M-CSF) and interleukin-6 (IL-6) than did control mice. Because M-CSF and IL-6 are important to bone marrow macrophage maturation, we formulated the hypothesis that suppressed macrophage development occurred as a result of the depressed levels of either M-CSF or IL-6. To test the hypothesis, mice were administered recombinant M-CSF or IL-6 intraperitoneally. We showed that recombinant M-CSF therapy, but not recombinant IL-6 therapy, reversed the suppressive effects of orthostatic suspension on macrophage development. These data suggest that bone marrow cells that produce M-CSF are affected by antiorthostatic suspension and may contribute to the inhibited maturation of bone marrow macrophage progenitors.

  20. [State of skeletal muscle fibers in rats during physical exercise after anti-orthostatic tail suspension in modeling the weightlessness].

    PubMed

    Kuznetsov, S L; Talis, V L

    1990-01-01

    The state of myofibers of types I, IIA and IIB of biceps femoris m. of Wistar rats exposed to tail suspension for 14 or 21 days was investigated after they experienced a 15-minute locomotor load: running on a treadmill or hindlimb stretching. In all types of myofibers both exposures prevented the development of most structural and metabolic changes that occurred in response to suspension simulating the physiological effects of weightlessness. The distribution and level of variations of muscle parameters depended on the kind of exposure and type of myofibers.

  1. Hematopoiesis in antiorthostatic, hypokinesic rats

    NASA Technical Reports Server (NTRS)

    Dunn, C. D. R.; Johnson, P. C.; Lange, R. D.

    1983-01-01

    Rats exposed to antiorthostatic, hypokinesia showed the following effects which are comparable to those seen in man during or after space flight: weight loss, reduced food and water consumption, transient increases in peripheral hematocrit and RBC count, decreasing MCV and reduced reticulocyte count. In addition, the hemoglobin P50 was shifted to the right. A significant shortening of RBC t1/2 was only seen after suspension. Changes in leukocyte and platelet numbers in suspended rats were also comparable to those in man during space flight, but leukocyte PHA sensitivity in rats showed no consistent alteration. The results demonstrate that this model reproduces many of the hematological effects of space flight and has potential as a tool in understanding the hematopoietic response to zero gravity.

  2. Hematopoiesis in antiorthostatic, hypokinesic rats

    NASA Technical Reports Server (NTRS)

    Dunn, C. D. R.; Johnson, P. C.; Lange, R. D.

    1983-01-01

    Rats exposed to antiorthostatic, hypokinesia showed the following effects which are comparable to those seen in man during or after space flight: weight loss, reduced food and water consumption, transient increases in peripheral hematocrit and RBC count, decreasing MCV and reduced reticulocyte count. In addition, the hemoglobin P50 was shifted to the right. A significant shortening of RBC t1/2 was only seen after suspension. Changes in leukocyte and platelet numbers in suspended rats were also comparable to those in man during space flight, but leukocyte PHA sensitivity in rats showed no consistent alteration. The results demonstrate that this model reproduces many of the hematological effects of space flight and has potential as a tool in understanding the hematopoietic response to zero gravity.

  3. Antiorthostatic posture as an earth model of the effect of microgravity on the human body.

    PubMed

    Nagy, E; Bencze, G; Csengery, A; Bognár, L; Almási, A

    1999-01-01

    We examined the horizontal and vertical component of diagonal optokinetic nystagmus (DOKN) in sitting posture and in the last 15 minutes of antiorthostatic posture at -30 degrees lasting 3 hours. The antiorthostatic posture is suited to the earthy model of the fluid shifting observed in microgravity. We found that the frequency of the vertical component of DOKN is rarer in antiorthostatic posture than in sitting posture. Moreover, the amplitude of the vertical component of DOKN is lower in antiorthostatic posture than is the amplitude of the horizontal component. According to our examinations, we suppose that the frequency and amplitude of vertical OKN are directed by different cerebral structures. Furthermore, we found that the heart rate becomes slower and the diastolic pressure is augmented after antiorthostatic posture and visual stimulation.

  4. Hormonal changes in antiorthostatic rats

    NASA Technical Reports Server (NTRS)

    Popovic, V.; Popovic, P.; Honeycutt, C.

    1982-01-01

    Hypokinesia, especially hypokinesia with negative tilt ('antiorthostatic hypokinesia'), mimics some of the effects of weightlessness. It is shown that cardiac output is increased during early exposure of rats to antiorthostatic hypokinesia. The increase of the stroke volume and of the cardiac output observed in the antiorthostatic hypokinetic rats is probably the consequence of a blood volume shift toward the chest brought forth by head-down positioning of the animals. It is also possible that struggling of the animals to escape from the harness and an increased metabolism contribute to the elevation of cardiac output. In order to study this hypothesis 'stress hormones' were measured in the antiorthostatic rats. Plasma levels of ACTH, corticosterone and prolactin were measured in the arterial blood (0.3 ml) sampled before, during and after hypokinesia from chronic aortic cannulas of the rats.

  5. Audiological findings in antiorthostatic position modelling microgravitation

    NASA Astrophysics Data System (ADS)

    Nagy, E.; Bencze, G.; Csengery, A.; Almasi, A.; Grosz, A.

    2005-08-01

    In our previous examinations we examined the behaviour of diagonal optokinetic nystagmus (DOKN), as well as the cardio-pulmonary changes in antiorthostatic posture (AP).The aim of our present study is the following: how modelled microgravitation influences the pure tone threshold and the speech threshold.The body fluids (blood, liquor, lymph) shift to the cranial direction because of the effect of microgravitation. Both the antigravitational muscular activity and the blood-vessel reflexes, which are habituated to the earthy relations, have got part in this. We examined the effect of cranial shifting of fluids in simulated microgravitational position caused by -300 antiorthostatic position lasting for 3 hours.

  6. Regulation of hematopoiesis in rats exposed to antiorthostatic hypokinetic/hypodynamia. II - Mechanisms of the 'anemia'

    NASA Technical Reports Server (NTRS)

    Dunn, C. D. R.; Johnson, P. C.; Lange, R. D.

    1986-01-01

    The cause of the red cell mass (RCM) deficit, which occurs in rats during suspenion, is investigated. The experimental conditions and procedures, in which male Sprague-Dawley rats are subjected to antiorthostatic hyypokinetic/hypodynamia and changes in RCM are monitored, are described. The influences of stress, reduced food and water consumption, and antiorhostatic posture on RCM are analyzed. Changes in body weight, RCM, radioiron incorporation, red blood cells (RBC), and reticulocytes, for the rats after head-down suspension are graphically presented; only the changes in RBC are related to the antiorthostatic posture. The data reveal that anemia is primarily caused by reduced food and water consumption and secondly by restricted movements.

  7. Regulation of hematopoiesis in rats exposed to antiorthostatic hypokinetic/hypodynamia. II - Mechanisms of the 'anemia'

    NASA Technical Reports Server (NTRS)

    Dunn, C. D. R.; Johnson, P. C.; Lange, R. D.

    1986-01-01

    The cause of the red cell mass (RCM) deficit, which occurs in rats during suspenion, is investigated. The experimental conditions and procedures, in which male Sprague-Dawley rats are subjected to antiorthostatic hyypokinetic/hypodynamia and changes in RCM are monitored, are described. The influences of stress, reduced food and water consumption, and antiorhostatic posture on RCM are analyzed. Changes in body weight, RCM, radioiron incorporation, red blood cells (RBC), and reticulocytes, for the rats after head-down suspension are graphically presented; only the changes in RBC are related to the antiorthostatic posture. The data reveal that anemia is primarily caused by reduced food and water consumption and secondly by restricted movements.

  8. Influence of suspension on the oxidative burst by rat neutrophils

    NASA Technical Reports Server (NTRS)

    Miller, E. S.; Koebel, D. A.; Davis, S. A.; Klein, J. B.; McLeish, K. R.; Goldwater, D.; Sonnenfeld, G.

    1994-01-01

    The influence of spaceflight on the oxidative burst of neutrophils is not known. The present study was designed to evaluate the influence of antiorthostatic suspension, a ground-based modeling system designed to simulate certain aspects of weightlessness that occur after spaceflight, on the capacity of rat neutrophils to express the oxidative burst, an important host defense mechanism against microbial pathogens. Rats were suspended in whole body harnesses in the antiorthostatic orientation for a 3- or 7-day period. Control rats were suspended orthostatically or allowed to remain in vivarium cages without the attachment of any suspension materials. After suspension, peripheral blood was harvested and neutrophils were isolated by density gradient centrifugation. The enriched neutrophil preparations were stimulated with N-formyl-methionyl-leucine-phenylalanine and phorbol myristic acid to induce the oxidative burst. It was found that neutrophils isolated from suspended animals released the same levels of superoxide anion as did vivarium control animals that were not suspended, indicating that whole body suspension did not alter this aspect of rat neutrophil function.

  9. Influence of suspension on the oxidative burst by rat neutrophils

    NASA Technical Reports Server (NTRS)

    Miller, E. S.; Koebel, D. A.; Davis, S. A.; Klein, J. B.; McLeish, K. R.; Goldwater, D.; Sonnenfeld, G.

    1994-01-01

    The influence of spaceflight on the oxidative burst of neutrophils is not known. The present study was designed to evaluate the influence of antiorthostatic suspension, a ground-based modeling system designed to simulate certain aspects of weightlessness that occur after spaceflight, on the capacity of rat neutrophils to express the oxidative burst, an important host defense mechanism against microbial pathogens. Rats were suspended in whole body harnesses in the antiorthostatic orientation for a 3- or 7-day period. Control rats were suspended orthostatically or allowed to remain in vivarium cages without the attachment of any suspension materials. After suspension, peripheral blood was harvested and neutrophils were isolated by density gradient centrifugation. The enriched neutrophil preparations were stimulated with N-formyl-methionyl-leucine-phenylalanine and phorbol myristic acid to induce the oxidative burst. It was found that neutrophils isolated from suspended animals released the same levels of superoxide anion as did vivarium control animals that were not suspended, indicating that whole body suspension did not alter this aspect of rat neutrophil function.

  10. Antiorthostatic hypokinesia and circulation in the rat

    NASA Technical Reports Server (NTRS)

    Popovic, V.

    1982-01-01

    Circulatory mechanisms that occur during exposure to head-down hypokinesia as well as during readaptation to control conditions were studied on unanesthetized unrestrained Sprague-Dawley rats exposed to hypokinesia for seven days. The heart rate was slightly elevated, and the right atrial pressure increased to 4 mm Hg, but returned to 0 mm Hg after three days of exposure. Mean arterial blood pressure decreased from 118 to 100 mm Hg during early exposure to antiorthostatic hypokinesia. Cardiac output and stroke volume of resting rats increased during early exposure to hypokinesia but decreased continuously during the next seven days. The results indicate that antiorthostatic hypokinesia induces circulatory changes similar to those seen in astronauts after several days of exposure to 0 g forces.

  11. [Heart functions in monkeys during a 2-week antiorthostatic hypokinesia

    NASA Technical Reports Server (NTRS)

    Krotov, V. P.; Convertino, V.; Korol'kov, V. I.; Latham, R.; Trambovetskii, E. V.; Fanton, J.; Crisman, R.; Truzhennikov, A. N.; Evert, D.; Nosovskii, A. M.; hide

    1996-01-01

    Dynamics of the left heart ventricular muscle contractility and compliance was studied in 4 monkeys in the head down position (antiorthostatic hypokinesia) with the body angle 10 during 2 weeks. Functional tests on a tilt table and under two conditions of centrifuge rotation were performed prior to and after the antiorthostatic hypokinesia. No changes in the left heart ventricular muscle contractility was found. However, the sensitivity level of the baroreflex control decreased. Compliance of the left heart myocardial fibre increased in the first hours and days of the antiorthostatic hypokinesia.

  12. Stokes and anti-stokes stimulated Mie scattering on nanoparticle suspensions of latex

    NASA Astrophysics Data System (ADS)

    Burkhanov, I. S.; Krivokhizha, S. V.; Chaikov, L. L.

    2016-12-01

    Stokes and anti-Stokes shifts of stimulated concentration light scattering (SCLS, stimulated Mie scattering) in suspensions of various-sized latex nanoparticles in water were measured by the light guide scheme, under conditions of backscattering in the presence of convection.

  13. Effects of antiorthostatic bedrest on the cardiorespiratory responses to exercise

    NASA Technical Reports Server (NTRS)

    Convertino, V. A.; Bisson, R.; Bates, R.; Goldwater, D.; Sandler, H.

    1981-01-01

    The cardiorespiratory changes in exercise performance induced by horizontal and antiorthostatic bed rest are compared in order to determine the physiological changes occurring in the antiorthostatic position and their degree of similarity to those observed in weightlessness. Systolic and diastolic pressures, heart rates, maximum oxygen uptake, ventilation volume during and following 5 min of submaximal exercise in the supine position and body weight and composition were determined in subjects before and following 7 days of bed rest in the horizontal or 6-deg head-down positions. Bed rest is found to result in a general decrease in exercise tolerance as indicated by cardiorespiratory parameters in both groups, with the 6-deg head-down treatment causing greater cardiovascular deconditioning. When compared with space flight data, the antiorthostatic position is shown to simulate the effects of weightlessness more effectively than horizontal bed rest

  14. Antiorthostatic immobilization with varied sodium intake

    NASA Astrophysics Data System (ADS)

    Hinghofer-Szalkay, H.; Haditsch, B.; Pilz, K.; Rössler, A.; Laszlo, Z.

    The study investigated, in 10 normotensive male persons, heart rate responses to graded lower body suction (LBNP) with adaptation to various oral sodium clamping during both ambulatory (AMB) conditions for 4 days, and thereafter to additional antiorthostatic (6° head down) positioning. A ,low' (LS: 143+/-10 mM Na +/ d excreted) and a ,high' (HS: 434+/-17 mM Na +/d excreted) sodium treatment - in randomized order and separated =1 mo - followed a ,conditioning' run with moderate sodium (237+/-9 mM Na +/d excreted). Urinary volume and sodium output were monitored, hormone levels (PRA, aldosterone, AVP) determined, and extracellular volume (ECV) estimated by whole body electrical impedance spectroscopy. ECV was not differently reduced (p>0.1) in LS (-5.8+/-2.3%, p=0.018) and HS (-4.0+/-1.0%. p=0.002). Morning AVP was lower (5.5+/-0.1 pg/ml) in HS than in LS (7.2+/-0.3 pg/ml; N=7 days), as well as aldosterone (69+/-7 pg/ml in HS vs. 180+/-24 pg/ml in LS). LBNP dose responses of PRA and aldosterone were higher in LS than HS after 8 days AOB, whereas microvascular fluid filtration was unchanged by any experimental condition. Heart rate responses to LBNP were unchanged by sodium supply, whereas mean arterial and pulse pressure was lower in LS than HS during all LBNP intensities. Thus, HS was able to increase arterial blood and pulse pressure and reduced PRA and aldosterone levels during graded simulated orthostatic challenge, but did neither ameliorate AOB-induced ECV decrease nor alter LBNP-induced filtration and heart rate responses. These results are relevant for planning of future countermeasures in astronauts. Supported by the Austrian Research Fund (P13451-MED)

  15. Nonlinear optical absorption and stimulated Mie scattering in metallic nanoparticle suspensions

    NASA Astrophysics Data System (ADS)

    He, Guang S.; Law, Wing-Cheung; Baev, Alexander; Liu, Sha; Swihart, Mark T.; Prasad, Paras N.

    2013-01-01

    The nonlinear optical properties of four metallic (Au-, Au/Ag-, Ag-, and Pt-) nanoparticle suspensions in toluene have been studied in both femtosecond and nanosecond regimes. Nonlinear transmission measurements in the femtosecond laser regime revealed two-photon absorption (2PA) induced nonlinear attenuation, while in the nanosecond laser regime a stronger nonlinear attenuation is due to both 2PA and 2PA-induced excited-state absorption. In the nanosecond regime, at input pump laser intensities above a certain threshold value, a new type of stimulated (Mie) scattering has been observed. Being essentially different from all other well known molecular (Raman, Brillouin) stimulated scattering effects, the newly observed stimulated Mie scattering from the metallic nanoparticles exhibits the features of no frequency shift and low pump threshold requirement. A physical model of induced Bragg grating initiated by the backward Mie scattering from metallic nanoparticles is proposed to explain the gain mechanism of the observed stimulated scattering effect.

  16. Soft-coupling suspension system for an intradural spinal cord stimulator: Biophysical performance characteristics

    NASA Astrophysics Data System (ADS)

    Oya, H.; Safayi, S.; Jeffery, N. D.; Viljoen, S.; Reddy, C. G.; Dalm, B. D.; Kanwal, J. K.; Gillies, G. T.; Howard, M. A.

    2013-10-01

    We have characterized the mechanical compliance of an improved version of the suspension system used to position the electrode-bearing membrane of an intradural neuromodulator on the dorsal pial surface of the spinal cord. Over the compression span of 5 mm, it exhibited a restoring force of 2.4 μN μm-1 and a mean pressure of 0.5 mm Hg (=66 Pa) on the surface below it, well within the range of normal intrathecal pressures. We have implanted prototype devices employing this suspension and a novel device fixation technique in a chronic ovine model of spinal cord stimulation and found that it maintains stable contact at the electrode-pia interface without lead fracture, as determined by measurement of the inter-contact impedances.

  17. Microfluidics study of intracellular calcium response to mechanical stimulation on single suspension cells.

    PubMed

    Xu, Tao; Yue, Wanqing; Li, Cheuk-Wing; Yao, Xinsheng; Yang, Mengsu

    2013-03-21

    A microfluidic microdevice was developed to exert mechanical stimulation on an individual suspension cell for mechanosensation research. In this microfluidic chip, an individual cell was isolated from a population of cells, and trapped in a microchannel with a compressive component made of a deflectable membrane. The mechanosensation of HL60 cells (leukemic cells) was studied using this chip, and the results showed that mechanical stimulations could trigger extracellular calcium to flow into HL60 cells through ion channels on cell membranes. The tension on individual HL60 cells exerted by the microdevice was showed large variations in the threshold of mechanosensation activation. In contrast to previous reports using patch clamp technique, there was little influence of cytoskeleton interruption on HL60 cell mechanosensation triggered by whole-cell compression. Additionally, two functional units were integrated in one chip for carrying out mechanosensation study in parallel, where HL60 cells (leukemic cells) and Jurkat cells (lymphocytes) were shown to respond to mechanical stimulation with different kinetics. The results demonstrated that the microfluidic device provides a novel approach to investigating the mechanosensation of single suspension cells in high-throughput.

  18. The spectra of stimulated concentration scattering (Mie scattering) on nanoparticles latex suspension in the presence of convection

    NASA Astrophysics Data System (ADS)

    Burkhanov, I. S.; Krivokhizha, S. V.; Chaikov, L. L.

    2016-09-01

    Spectral shifts of the stimulated concentration light scattering (SCLS, stimulated Mie scattering) in suspensions of various sized latex nanoparticles in water were measured by the light guide scheme in conditions of the backscattering in the presence of convection. It is shown that the spectral shift can be either negative or positive depending on the particle size.

  19. Stimulated concentration (diffusion) light scattering on nanoparticles in a liquid suspension

    NASA Astrophysics Data System (ADS)

    Burkhanov, I. S.; Krivokhizha, S. V.; Chaikov, L. L.

    2016-06-01

    A nonlinear growth of the light scattering intensity has been observed and the frequency shift of the spectral line of scattered light has been measured in light backscattered in suspensions of diamond and latex nanoparticles in water. The shift corresponds to the HWHM of the line of spontaneous scattering on particles. We may conclude that there exists stimulated concentration (diffusion) light scattering on variations of the particle concentration, which is also called the stimulated Mie scattering. In a fibre probe scheme, the growth of the shift of the scattered spectral line is observed with an increase in the exciting beam power. The variation of the frequency shift with an increase in the exciting power is explained by convection in liquid.

  20. Model for antiorthostatic hypokinesia - Head-down tilt effects on water and salt excretion

    NASA Technical Reports Server (NTRS)

    Deavers, D. R.; Musacchia, X. J.; Meininger, G. A.

    1980-01-01

    Water and electrolyte excretion was investigated in antiorthostatic hypokinetic and orthostatic hypokinetic and control rats in metabolic cages. Significant (t test, P less than 0.05) diuresis, natriuresis, and kaliuresis occurred in the antiorthostatic hypokinetic subjects but did not occur in either the orthostatic hypokinetic or controls. Recovery from antiorthostatic hypokinesia was characterized by retention of water, sodium, and potassium. Patterns of changes in body weight and food and water consumption were virtually identical in antiorthostatic and orthostatic hypokinetic rats and thus could not account for the differences in renal handling of water and electrolytes. Also, differences in ingestion of food and water in controls could not account for differences in excretion of water and electrolytes between these and antiorthostatic hypokinetic rats. It was concluded that the antiorthostatic position was responsible for the diuresis and natriuresis and that the antiorthostatic hypokinetic rat appears to be a good model for the study of water and elecrolyte excretion during conditions such as bed rest, water immersion, and exposure to weightlessness.

  1. Model for antiorthostatic hypokinesia - Head-down tilt effects on water and salt excretion

    NASA Technical Reports Server (NTRS)

    Deavers, D. R.; Musacchia, X. J.; Meininger, G. A.

    1980-01-01

    Water and electrolyte excretion was investigated in antiorthostatic hypokinetic and orthostatic hypokinetic and control rats in metabolic cages. Significant (t test, P less than 0.05) diuresis, natriuresis, and kaliuresis occurred in the antiorthostatic hypokinetic subjects but did not occur in either the orthostatic hypokinetic or controls. Recovery from antiorthostatic hypokinesia was characterized by retention of water, sodium, and potassium. Patterns of changes in body weight and food and water consumption were virtually identical in antiorthostatic and orthostatic hypokinetic rats and thus could not account for the differences in renal handling of water and electrolytes. Also, differences in ingestion of food and water in controls could not account for differences in excretion of water and electrolytes between these and antiorthostatic hypokinetic rats. It was concluded that the antiorthostatic position was responsible for the diuresis and natriuresis and that the antiorthostatic hypokinetic rat appears to be a good model for the study of water and elecrolyte excretion during conditions such as bed rest, water immersion, and exposure to weightlessness.

  2. Changes in the status of the human tibia during antiorthostatic hypokinesia

    NASA Technical Reports Server (NTRS)

    Tatarinov, A. M.; Grigoryev, A. I.; Dzenis, V. V.; Yanson, Kh. A.; Oganov, V. S.; Rakhmanov, A. S.

    1988-01-01

    Changes were studied in biomechanical properties of the human tibia during prolonged antiorthostatic hypokinesia with different modes of motor activity and pharmacotherapy and comparison of results obtained with parallel examinations using ultrasonic diagnosis and photon absorptiometry.

  3. [Features of the pharmacokinetics of ceftriaxone during the antiorthostatic hypokinesia in rats].

    PubMed

    Baranov, M V; Arkhipova, E N; Lebedeva, M A; Khlebnikova, N N; Medvedeva, Yu S

    2014-01-01

    This study was designed to investigate the effects of simulated microgravity on the plasma kinetics of ceftriaxone in rats. Comparative analysis of pharmacokinetic parameters in control and experimental groups has revealed the influence of antiorthostatic hypokinesia (ANOH) on the pharmacokinetics of ceftriaxone. Decreased level of maximum plasma concentration (C(max)) and bioavailability of ceftriaxone after single intramuscular (IM) injection were revealed in rats with antiorthostatic hypokinesia. The rate of absorption of the drug was higher respectively.

  4. Regulation of calcium metabolism during prolonged antiorthostatic hypokinesia

    NASA Technical Reports Server (NTRS)

    Grigoryev, A. I.; Morukov, B. V.; Dorokhova, B. R.; Rustamyan, L. A.

    1988-01-01

    Characteristics of the regulation of calcium exchange in healthy persons exposed to 182 days of antiorthostatic hypokinesia are investigated. Total calcium concentrations, ionized calcium activities and parathyroid hormone concentrations in blood serum were determined, before, during, and up to 15 days after a 182-day period of strict bed rest at a head down tilt of 4 deg; and tests of blood urine responses to a calcium lactate stress were performed to study the role of the kidneys. An increase in calcium ion activity is observed during the period of hypokinesia, while total calcium concentrations changed to a lesser degree. Plasma parathyroid hormone levels are found to significantly exceed background levels during hypokinesia and in the recovery period immediately following. Finally, the increase in calcium excretion in the urine during prolonged limitations of muscular activity is found to be connected with both an enhancement of calcium filtration and a decrease in its reabsorption in the kidneys, possibly due to changes in hormonal regulation.

  5. Pulsed electric field stimulates plant secondary metabolism in suspension cultures of Taxus chinensis.

    PubMed

    Ye, Hong; Huang, Lin-Ling; Chen, Shu-De; Zhong, Jian-Jiang

    2004-12-20

    The effects of pulsed electric field (PEF) on growth and secondary metabolite production by plant cell culture were investigated by using suspension cultures of Taxus chinensis as a model system. Cultured cells in different growth phases were exposed to a PEF (50 Hz, 10 V/m) for various periods of time. A significant increase in intracellular accumulation of taxuyunnanine C (Tc), a bioactive secondary metabolite, was observed by exposing the cells in the early exponential growth phase to a 30-min PEF. The Tc content (i.e., the specific production based on dry cell weight) was increased by 30% after exposure to PEF, without loss of biomass, compared with the control. The combination of PEF treatment and sucrose feeding proved useful for improving secondary metabolite formation. Production levels of reactive oxygen species, extracellular Tc, and phenolics were all increased, whereas cell capacitance was decreased with PEF treatment. The results show that PEF induced a defense response of plant cells and may have altered the cell/membrane's dielectric properties. PEF, an external stimulus or stress, is proposed as a promising new abiotic elicitor for stimulating secondary metabolite biosynthesis in plant cell cultures.

  6. Production and secretion of biologically active human granulocyte-macrophage colony stimulating factor in transgenic tomato suspension cultures.

    PubMed

    Kwon, Tae-Ho; Kim, Young-Sook; Lee, Jae-Hwa; Yang, Moon-Sik

    2003-09-01

    A complementary DNA encoding human granulocyte-macrophage colony stimulating factor (hGM-CSF) was cloned and introduced into tomato (Lycopersicon esculentum cv. Seokwang) using Agrobacterium-mediated transformation. Genomic PCR and Northern blot analysis demonstrated the integration of the construction into the plant nuclear genome and expression of the hGM-CSF in transgenic tomato. The cell suspension culture was established from leaf-derived calli of the transgenic tomato plants transformed with the hGM-CSF gene. Recombinant hGM-CSF was synthesized by the transgenic cell culture and secreted into the growth medium at 45 microg l(-1) after 10 d' cultivation.

  7. Pharmacokinetics of Scopolamine Intranasal Gel Formulation (INSCOP) During Antiorthostatic Bedrest

    NASA Technical Reports Server (NTRS)

    Putcha, L.; Du, B.; Daniels, V.

    2010-01-01

    Space Motion Sickness (SMS) is experienced during early flight days of space missions and on reduced gravity simulation flights which require treatment with medications. Oral administration of scopolamine tablets is still a common practice to prevent SMS symptoms. Bioavailability of medications taken by mouth for SMS is often low and variable. Intranasal (IN) administration of medications has been reported to achieve higher and more reliable bioavailability than from an equivalent oral dose. In this FDA reviewed phase II clinical trial, we evaluated pharmacokinetics of an investigative new drug formulation, INSCOP during ambulatory (AMB) and antiorthostatic bedrest (HBR), a ground-based microgravity analog. Twelve subjects including 6 males and 6 females received 0.2 and 0.4 mg doses of INSCOP on separate days during AMB and ABR in a randomized, double blind cross over experimental design. Blood samples were collected at regular time intervals for 24 h post dose and analyzed for free scopolamine concentrations by an LC-MS-MS method. Pharmacokinetic parameters were calculated using concentration versus time data and compared between AMB and ABR conditions. Results indicated that maximum concentration and relative bioavailability increased marginally during ABR compared to AMB; differences in PK parameters between AMB and ABR were greater with 0.2 mg than with 0.4 mg dose. Gender specific differences in PK parameters was observed both during AMB and ABR with differences higher in females between the two conditions than in males. A significant observation is that while gender differences in PK appear to exist, the differences in primary PK parameters between AMB and ABR after IN administration, unlike oral administration, are minimal and may not be clinically significant for both genders.

  8. Alteration of the state of the human tibia during antiorthostatic hypokinesis

    NASA Astrophysics Data System (ADS)

    Tatarinov, A. M.; Grigor'ev, A. I.; Dzenis, V. V.; Yanson, Kh. A.; Oganov, V. S.; Rakhmanov, A. S.

    1986-01-01

    During the 120-day observations of the state of the tibia under conditions of antiorthostatic hypokinesis and various regimes of motor activity and pharmacotherapy we noted a considerable variability of the acoustic properties of the bone (ultrasonic diagnosis) and mineral component content (photon absorptiometry).

  9. Suspension restraint - Induced hypokinesia and antiorthostasis as a simulation of weightlessness

    NASA Technical Reports Server (NTRS)

    Musacchia, X. J.; Steffen, J. M.; Deavers, D. R.

    1982-01-01

    Muscle, renal, fluid and electrolyte responses were measured in suspended rats; the hind limbs are non-load bearing and the front limbs can be used for feeding and grooming. Hind limb hypokinesia reverses after removal from the suspension harness. This suspension system is adjustable for a head-down tilt to produce antiorthostatic responses which are also reversible. Responses to hypokinesia or antiorthostatic hypokinesia for up to 14 days were measured, e.g., muscle atrophy: soleus greater than gastrocnemius equals plantaris greater than extensor digitorum longus, kaliuresis, and increased excretion of urea, NH3, and 3 methylhistidine. Muscle protein loss, a response to a reduction in RNA, is also reversible. A head-down tilt for 7-14 days results in diuresis and natriuresis. These changes are reversed within 24 hours after removal from the restraint harness. Physiological effects of suspension restraint can be used to simulate and predict responses to microgravity exposure.

  10. Chronic orthostatic and antiorthostatic restraint induce neuroendocrine, immune and neurophysiological disorders in rats

    NASA Astrophysics Data System (ADS)

    Assenmacher, I.; Mekaouche, M.; Maurel, D.; Barbanel, G.; Givalois, L.; Boissin, J.; Malaval, F.; Ixart, G.

    The tail-cast suspension rat model has been developed in ground laboratories interested in space physiology for extensive study of mechanisms causing the pathophysiological syndrome associated with space flights. We used individually-caged male rats to explore the effects of acute and chronic (7d) orthostatic restraint (OR) and head-down anti-orthostatic restraint (AOR) on a series of physiological variables. The acute restraint study showed that (1) the installation of the OR device induced an acute reaction for 2 days, with a substantial rise in ACTH (x2) and CORT (x6), and that (2) the head-down tilt from OR to AOR induced (i) within 10 min and lasting 60 min a 2-fold rise in the intra-cerebro-ventricular pressure (Picv) monitored with an icv telemetric recording system, which receded to normal between 60 and 120 min; and (ii) within 30 min a short-lived 4-fold rise in plasma ACTH and CORT levels. Chronic OR induced (1) the suppression of the diurnal ACTH/CORT rhythm, with increased mean levels, especially for ACTH, (2) a degraded circadian locomotor activity rhythm manifested by a significant reduction in the spectral power of the 24h periodicity and a concomitant emergence of shorter (ultradian) periodicities, (3) an associated, but less pronounced alteration of the diurnal rhythm in body temperature; and (4) a marked increase in baseline plasma levels of IL-1β and an increased reactivity in cytokine release following an E. coli endotoxin (LPS) challenge. AOR induced (1) a similar obliteration of the circadian ACTH/CORT rhythm, (2) the loss of close correlation between ACTH and CORT, (3) a generalized increase in baseline plasma IL-1β levels and (4) more extensive degradation of the arcadian periodicity for both locomotor activity and, to a lesser extent, body temperature, replaced by dominant spectral powers for ultradian periodicities (3 to 10h). In conclusion, both experimental paradigms — but AOR more than OR — caused a blockade of the arcadian

  11. Enhanced diffusion self-stimulated by micro-algae in an active, aerotactic bacterial suspension

    NASA Astrophysics Data System (ADS)

    Peaudecerf, François; Goldstein, Raymond E.

    2014-11-01

    Suspensions of swimming bacteria form a new class of active fluids that generate complex phenomena. An ``active bath'' of bacteria for instance produces fluid flows which move passive colloids in a random-like walk, associated with an effective diffusion coefficient higher than for Brownian motion. The value of this enhanced diffusion coefficient depends on the local density of bacteria and their swimming behavior. However, with aerotactic, obligate aerobic bacteria such as B. subtilis, the local oxygen concentration impacts on the distribution of cells and their swimming behavior. We consider the specific case in which non-motile photosynthetic algal cells interacting with a B. subtilis suspension not only play the role of passive colloids, but also produce oxygen under light. We demonstrate that this new kind of active suspension, under heterogeneous illumination, can induce an effective negative phototaxis of the passive algal cells. We explain the origin of this novel phenomenon as the combination of algal oxygen production, diffusion, chemotaxis and motility switching in bacteria resulting in an heterogeneous enhanced diffusion. Finally, we present potential applications for algal cell mixing and sorting, that can inspire new methods for bioengineering. Supported by ERC, Raymond and Beverly Sackler Foundation, and Mines ParisTech.

  12. A fullerene colloidal suspension stimulates the growth and denitrification ability of wastewater treatment sludge-derived bacteria.

    PubMed

    Huang, Fei; Ge, Ling; Zhang, Bo; Wang, Yun; Tian, Hao; Zhao, Liping; He, Yiliang; Zhang, Xiaojun

    2014-08-01

    Fullerene (C60) is a nanoparticle that has been widely studied and applied in numerous commodities. However, there are concerns regarding its potential negative impact on the environment. A fullerene colloidal suspension (nC60) is known for its property of selectively inhibiting the growth of microorganisms. In this study, using denaturing gradient gel electrophoresis fingerprinting technology, we found that fullerene altered the structure of a sludge-derived microbial community. Specifically, the bacteria from Bacillus, Acidovorax and Cloacibacterium genera were enriched in abundance when supplemented with nC60 at pH 6.5 under aerobic conditions. The effects of the fullerene colloidal suspension on a strain of Bacillus isolated from the same microbial community were evaluated to further characterize the growth-stimulating effect of nC60. The biomass of cultures of this strain incubated with nC60 concentrations ranging from 3 mg L(-1) to 7 mg L(-1) was approximately twice that of the control during the stationary phase. The fullerene also induced higher superoxide dismutase activity in Bacillus cereus. Furthermore, the nitrate removal rate of B. cereus increased to nearly 55% in the presence of 5 mg L(-1) nC60, compared to 35% for the control. Meanwhile, the cumulative loading amount of nitrite was reduced from 33 μg mL(-1) to 25 μg mL(-1) by the addition of 5 mg L(-1) nC60. Our results demonstrate that the fullerene colloidal suspension is conditionally capable of promoting the growth and denitrification metabolism of certain bacteria, such as B. cereus. Fullerene might have both inhibitory and stimulatory effects on microorganisms in various environments.

  13. [Laws of typological interactions of clino- and antiorthostatic systemic and cerebral circulation in children].

    PubMed

    Gavrikov, K V; Isupov, I B

    1999-01-01

    Based on P. K. Anokhin's systems approach, the authors analyze the typological features of the mechanisms of clinostatic and anti-orthostatic systemic and cerebral circulation in children aged 7-9 years. Children with eukinetic systemic circulation have stable total peripheral vascular resistance in antiorthostasis, the mechanisms of cerebral hemodynamic regulation ensure constriction of local arterioles, those with hypokinetic systemic circulation have decreased total peripheral vascular resistance and lower constriction of cerebral arteries and arterioles. In hyperkinetic circulation, total peripheral resistance increases with slight constriction of cerebral arterioles and marked deterioration of venous blood outflow from the cerebral pool. The typological features of systemic and cerebral circulation should be borne in mind in pediatric clinical practice. The findings allow one to mathematically predict the changes occurring in anti-orthostatic hemodynamics in the context of its typological features.

  14. Stimulated low frequency Raman scattering in cupric oxide nanoparticles water suspension

    NASA Astrophysics Data System (ADS)

    Averyushkin, A. S.; Baranov, A. N.; Bulychev, N. A.; Kazaryan, M. A.; Kudryavtseva, A. D.; Strokov, M. A.; Tcherniega, N. V.; Zemskov, K. I.

    2017-04-01

    Cupric oxide nanoparticles with average size of 213.2 nm, were synthesized in acoustoplasma discharge for investigating their vibrational properties. The low-frequency acoustic mode in cupric oxide (CuO) nanoparticles has been studied by stimulated low-frequency Raman scattering (SLFRS). SLFRS conversion efficiency, threshold and frequency shift of the scattered light are measured.

  15. Chloride secretagogues stimulate inositol phosphate formation in shark rectal gland tubules cultured in suspension

    SciTech Connect

    Ecay, T.W.; Valentich, J.D. )

    1991-03-01

    Neuroendocrine activation of transepithelial chloride secretion by shark rectal gland cells is associated with increases in cellular cAMP, cGMP, and free calcium concentrations. We report here on the effects of several chloride secretagogues on inositol phosphate formation in cultured rectal gland tubules. Vasoactive intestinal peptide (VIP), atriopeptin (AP), and ionomycin increase the total inositol phosphate levels of cultured tubules, as measured by ion exchange chromatography. Forskolin, a potent chloride secretagogue, has no effect on inositol phosphate formation. The uptake of {sup 3}H-myo-inositol into phospholipids is very slow, preventing the detection of increased levels of inositol trisphosphate. However, significant increases in inositol monophosphate (IP1) and inositol biphosphate (IP2) were measured. The time course of VIP- and AP-stimulated IP1 and IP2 formation is similar to the effects of these agents on the short-circuit current responses of rectal gland monolayer cultures. In addition, aluminum fluoride, an artificial activator of guanine nucleotide-binding proteins, stimulates IP1 and IP2 formation. We conclude that rectal gland cells contain VIP and AP receptors coupled to the activation of phospholipase C. Coupling may be mediated by G-proteins. Receptor-stimulated increases in inositol phospholipid metabolism is one mechanism leading to increased intracellular free calcium concentrations, an important regulatory event in the activation of transepithelial chloride secretion by shark rectal gland epithelial cells.

  16. Stimulated low-frequency Raman scattering in a suspension of tobacco mosaic virus

    NASA Astrophysics Data System (ADS)

    Karpova, O. V.; Kudryavtseva, A. D.; Lednev, V. N.; Mironova, T. V.; Oshurko, V. B.; Pershin, S. M.; Petrova, E. K.; Tcherniega, N. V.; Zemskov, K. I.

    2016-08-01

    The interaction of laser pulses with tobacco mosaic virus (TMV) in Tris-HCl pH7.5 buffer and in water has been investigated. Ruby laser pulses of 20 ns duration have been used for excitation. The spectrum of the light passing through the sample was registered with the help of a Fabry-Perot interferometer. In the case of TMV in water we observed in the spectrum only one line of the exciting laser light, but for TMV in Tris-HCl pH7.5 buffer a second line appeared, corresponding to stimulated low-frequency Raman scattering (SLFRS) on the breathing radial mode of TMV. The frequency shift of the SLFRS by 2 cm-1 (60 GHz), the conversion efficiency and the threshold are measured for the first time to the best of our knowledge.

  17. Certain peculiarities of the functioning of the cardiovascular system in bedrest conditions during horizontal and antiorthostatic body positions

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The adequate modeling of physiological reactions inherent to the state of weightlessness has become a matter of particular urgency in space medicine. This modeling is necessary for studying the phenomenology and degree of disorders, prognostication of the crew's health, and developing the various preventive measures employed in space flights. A comparison is made of the physiological effects brought about by bed rest in a horizontal and antiorthostatic body position. A study is done of the influence of brief antiorthostatic hypokinesia, simulating the acute period of adaptation to weightlessness, on circulation and on a number of involved analytical systems. The basic model accepted is antiorthostatic hypokinesia with a body position declination angle of 4 deg (head lower than feet). The experiment's duration is dictated by the objectives of the research.

  18. Structure of Immune Stimulating Complex Matrices and Immune Stimulating Complexes in Suspension Determined by Small-Angle X-Ray Scattering

    PubMed Central

    Pedersen, Jan Skov; Oliveira, Cristiano L.P.; Hübschmann, Henriette Baun; Arleth, Lise; Manniche, Søren; Kirkby, Nicolai; Nielsen, Hanne Mørck

    2012-01-01

    Immune stimulating complex (ISCOM) particles consisting of a mixture of Quil-A, cholesterol, and phospholipids were structurally characterized by small-angle x-ray scattering (SAXS). The ISCOM particles are perforated vesicles of very well-defined structures. We developed and implemented a novel (to our knowledge) modeling method based on Monte Carlo simulation integrations to describe the SAXS data. This approach is similar to the traditional modeling of SAXS data, in which a structure is assumed, the scattering intensity is calculated, and structural parameters are optimized by weighted least-squares methods when the model scattering intensity is fitted to the experimental data. SAXS data from plain ISCOM matrix particles in aqueous suspension, as well as those from complete ISCOMs (i.e., with an antigen (tetanus toxoid) incorporated) can be modeled as a polydisperse distribution of perforated bilayer vesicles with icosahedral, football, or tennis ball structures. The dominating structure is the tennis ball structure, with an outer diameter of 40 nm and with 20 holes 5–6 nm in diameter. The lipid bilayer membrane is 4.6 nm thick, with a low-electron-density, 2.0-nm-thick hydrocarbon core. Surprisingly, in the ISCOMs, the tetanus toxoid is located just below the membrane inside the particles. PMID:22677391

  19. Stimulation and artifact-free extracellular electrophysiological recording of cells in suspension.

    PubMed

    Myers, Frank B; Abilez, Oscar J; Zarins, Chris K; Lee, Luke P

    2011-01-01

    We have developed instrumentation which stimulates and records electrophysiological signals from populations of suspended cells in microfluidic channels. We are employing this instrumentation in a new approach to cell sorting and flow cytometry which distinguishes cells based on their electrophysiology. This label-free approach is ideal for applications where labeling or genetic modification of cells is undesirable, such as in purifying cells for tissue replacement therapies. Electrophysiology is a powerful indicator of phenotype for electrically-excitable cells such as myocytes and neurons. However, extracellular field potential signals are notoriously weak and large stimulus artifacts can easily obscure these signals if care is not taken to suppress them. This is particularly true for suspended cells. Here, we describe a novel microelectrode configuration and the associated instrumentation for suppressing stimulus artifacts and faithfully recovering the extracellular field potential signal. We show that the device is capable of distinguishing cardiomyocytes from non-cardiomyocytes derived from the same stem cell population. Finally, we explain the relationship between extracellular field potentials and the more familiar transmembrane action potential signal, noting the physiologically important features of these signals.

  20. Hindlimb-suspension and spaceflight both alter cGMP levels in rat choroid plexus.

    PubMed

    Carcenac, C; Herbute, S; Masseguin, C; Mani-Ponset, L; Maurel, D; Briggs, R; Guell, A; Gabrion, J B

    1999-10-01

    Effects of actual and simulated weightlessness on choroidal guanylate cyclase activity were evaluated by assaying the production of cyclic guanosine monophosphate (cGMP), a second messenger involved in mechanisms regulating the secretion of cerebrospinal fluid (CSF) in choroid plexus. Cyclic cGMP was measured, using radio-immunoassay, in choroidal extracts of hindlimb-suspended rats (HLS rats), adapted to an anti-orthostatic restraint for 30 min., or for 3, 9 or 14 days and after a 17-day spaceflight (Life and Microgravity SpaceLab experiment; LMS). Basal cGMP levels were slightly but significantly decreased in the first 30 min. of the HLS experiment, whereas they were significantly increased in rats adapted to longer anti-orthostatic restraints. LMS flight rats demonstrated a similar increase in the choroidal cGMP baseline. After natriuretic peptide stimulation, i.e. using ANP (atrial natriuretic peptide) or BNP (brain natriuretic peptide), choroidal cGMP contents were typically increased (by 1.5-2 times; p<0.05) in control rats (LMS and HLS experiments), but not significantly elevated in suspended rats, except for those adapted to HLS for 14 days. In these animals the ANP-dependent cGMP production was significantly increased (by about 3 times; p<0.005). The ANP- or BNP-dependent responses were similarly abolished in LMS flight rats, which were dissected 4-6 hours after return to Earth's gravity. The role of corticosteroids was also investigated during the LMS experiment. Results on choroidal functions revealed a lack of significant change of cGMP levels between adrenalectomized and sham-operated rats. For the first time, it is reported that both basal and ANP- stimulated cGMP levels are dramatically changed over the first 14 days of suspension, i.e. with experiments known to simulate some effects of weightlessness. Basal choroidal cGMP levels are also increased after 17 days in space, suggesting that space adaptation also impacts choroidal guanylate cyclase

  1. Antiorthostatic test as a model to study antigravity mechanisms of the cardiovascular system.

    PubMed

    Yarullin, K K; Vasilyeva, T D; Alekseev, D A

    1976-01-01

    The paper presents rheographic investigations of regional haemodynamics (brain, lungs, liver and limbs) during antiorthostatic exposures of varying intensity (-15, -30, -45 degrees, times of exposure 20, 40 and 60 min). Our findings show that the pattern and time of the function of compensatory mechanisms preventing excessive vascular compliance [correction of complicance] under the influence of the hydrostatic blood column depend on the value and length of antiorthostasis, because prolonged venous congestion results not only in congestive circulatory hypoxia but also in arterial hypoxia due to compensatory limitation of arterial inflow.

  2. Effect of antiorthostatic bed rest on hepatic blood flow in man

    NASA Technical Reports Server (NTRS)

    Putcha, L.; Cintron, N. M.; Vanderploeg, J. M.; Chen, Y.; Habis, J.

    1988-01-01

    Physiological changes that occur during exposure to weightlessness may induce alterations in blood flow to the liver. Estimation of hepatic blood flow (HBF) using ground-based weightlessness simulation models may provide insight into functional changes of the liver in crewmembers during flight. In the present study, HBF, indirectly estimated by indocyanine gree (ICG) clearance, is compared in 10 subjects during the normal ambulatory condition and antiorthostatic (-6 deg) bed rest. Plasma clearance of ICG was determined following intravenous administration of a 0.5-mg/kg dose of ICG to each subject on two separate occasions: once after being seated for 1 h, and once after 24 h of head-down bed rest. After 24 h of head-down bed rest, hepatic blood flow did not change significantly from the respective control value.

  3. Effect of antiorthostatic bed rest on hepatic blood flow in man

    NASA Technical Reports Server (NTRS)

    Putcha, L.; Cintron, N. M.; Vanderploeg, J. M.; Chen, Y.; Habis, J.

    1988-01-01

    Physiological changes that occur during exposure to weightlessness may induce alterations in blood flow to the liver. Estimation of hepatic blood flow (HBF) using ground-based weightlessness simulation models may provide insight into functional changes of the liver in crewmembers during flight. In the present study, HBF, indirectly estimated by indocyanine gree (ICG) clearance, is compared in 10 subjects during the normal ambulatory condition and antiorthostatic (-6 deg) bed rest. Plasma clearance of ICG was determined following intravenous administration of a 0.5-mg/kg dose of ICG to each subject on two separate occasions: once after being seated for 1 h, and once after 24 h of head-down bed rest. After 24 h of head-down bed rest, hepatic blood flow did not change significantly from the respective control value.

  4. [Oxidation Stress Markers Dynamics in the Experiment of Long-Term Antiorthostatic Hypokinesia (Retrospective Study)].

    PubMed

    Zhuravlyova, O A; Markin, A A; Kuzichkin, D S; Loginov, V I; Zabolotskaya, I V; Vostrikova, L V

    2016-01-01

    In blood serum of 9 volunteers aged 27 to 42, participated in the experiment with 370-day antiorthostatic hypokinesia (-5 degrees), the lipid peroxidation derivates concentration--diene conjugates (DC), malonic dialdehyde (MDA), Schiff bases (SB) as well as antioxidant defense system indices--tocopherol (TP) concentration and total antioxidative activity level (AOA) were measured. The volunteers were divided into two groups subjected to physical training regimes and used prophylactic measures. In both groups the lipoperoxidation processes initial stages depression (by 54-73%) was observed starting from 50th day, thus the lipid peroxidation final product--SB level was decreased (by 50-61%) only to the 230 day and remains approximately at the same level till the end of the experiment. The restorative period was characterized by decreasing (in 1.6-2.3 times) of MDA and SB concentrations. The decrease in lotal AOA during the aftereffect period was detected in all volunteers, and its level was significantly lower physiological norm range. Probably, long-term adaptation to the simulated weightlessness conditions is accompanied by expressed decrease in biological oxidation processes intensity and significant stress effect, as indicates by essential depression of lipid free radical oxidation in the course of the experiment. At the same time the restorative period after 370-day antiorthostatic hypokinesia was characterized by significantly expressed and prolonged readaptation stress progress. It is evidenced by practically twofold decrease in lipoperoxidation processes intensity against significant increase in TP concentration and water-soluble antioxidants functional reserves exhaustion. Lipid peroxidation activation absence in all terms of examination reflects appropriate compensation of studying impact by volunteers.

  5. Stimulation of betacyanin synthesis through exogenous methyl jasmonate and other elicitors in suspension-cultured cells of Portulaca.

    PubMed

    Bhuiyan, Nazmul H; Adachi, Taiji

    2003-09-01

    Betacyanin production in suspension-cultured cells of Portulaca was significantly enhanced by both abiotic and biotic elicitors. Betacyanin levels increased 1.3 and 1.5-fold over the controls in the presence of two abiotic elicitors (20 mumol/L CuSO4 and 100 mumol/L FeEDTA) and increased 1.8 and 1.6-fold in the presence of two biotic elicitors (0.5 mg/L beta-glucan and 0.5 mg/L chitosan). Maximum betacyanin synthesis with the two most effective elicitors was obtained when cultures were treated on day 1 and day 0 by beta-glucan and FeEDTA, respectively. A concentration-dependent response was exhibited by cultures treated with exogenous methyl jasmonate (MJ). MJ alone at 0.1 mumol/L caused a 2.6-fold increase in betacyanin synthesis when administered to the suspension culture on day 3. However, no additive effect on betacyanin accumulation was observed in treatments, which combined MJ and beta-glucan or FeEDTA. Treatment with ibuprofen (IB), an inhibitor of jasmonate biosynthesis, reduced the level of betacyanin in cells cultured in standard medium at all concentrations tested (25, 50, 100 mumol/L). The effect of IB on betacyanin synthesis in the cells treated with MJ or beta-glucan, however, differed with the IB concentration applied. The two higher concentrations (50 and 100 mumol/L) of IB significantly reduced the betacyanin content while the lower concentration (25 mumol/L) did not show an adverse effect on the betacyanin enhancement triggered by MJ or beta-glucan. Our findings suggest that, in suspension-cultured cells of Portulaca, an MJ-mediated signal transduction pathway prominently exists in betacyanin synthesis. This pathway seems to act antagonistically towards beta-glucan-mediated signaling. As far as we know this is the first report on the elevation of betacyanin level by jasmonate or other elicitors in cell suspension cultures.

  6. Pharmacokinetics of Intranasal Scopolamine Gel Formation During Antiorthostatic Bedrest - A Microgravity Analog

    NASA Technical Reports Server (NTRS)

    Lakshmi, Putcha; Singh, R. P.; Crady, V. A.; Derendorf, H.

    2011-01-01

    Space Motion sickness (SMS) is an age old problem for astronauts on both short and long duration space flights. Scopolamine (SCOP) is the most frequently used drug for the treatment of motion sickness (MS) which is currently available in transdermal patch and tablet dosage forms. These formulations of SCOP are ineffective for the treatment of SMS. Intranasal dosage forms are noninvasive with rapid absorption and enhanced bioavailability thus allowing precise and reduced dosing options in addition to offering rescue and treatment options. As such, an intranasal gel dosage formulation of scopolamine (INSCOP) was developed and Pharmacokinetics (PK) and bioavailability were determined under IND guidelines. The present clinical trial compares PK and bioavailability of INSCOP in 12 normal, healthy subjects (6 male/ 6 female) during ambulation (AMB) and antiorthostatic bedrest (ABR) used as a ground-based microgravity analog. Subjects received 0.2 and 0.4 mg doses of INSCOP during AMB and ABR in a four-way crossover design. Results indicated no difference between AMB and ABR in PK parameters after 0.2 mg dose. Clearance (Cls) decreased with a concomitant increase in maximum concentration and area under concentration versus time curve (AUC) during ABR after the 0.4 mg dose. This difference in AUC and Cls at the higher but not the lower dose during ABR may suggest that ABR may affect metabolism and/or clearance at higher doses of INSCOP. These results indicate that dosing adjustment may be required for treatment of SMS with INSCOP in space.

  7. Enhancement of anthraquinone production in Morinda citrifolia cell suspension cultures after stimulation of the proline cycle with two proline analogs.

    PubMed

    Quevedo, Carla V; Perassolo, María; Giulietti, Ana M; Rodríguez Talou, Julián

    2012-03-01

    Synthesis of anthraquinones (AQs) involves the shikimate and 2-C-methyl-D-erythritol 4-phosphate pathways. The proline cycle is linked to the pentose phosphate pathway (PPP) to generate NADPH needed in the first steps of this pathway. The effect of two proline analogs, azetidine-2-carboxylic acid (A2C) and thiazolidine-4-carboxylic acid (T4C), were evaluated in Morinda citrifolia suspension cultures. Both analogs gave higher proline accumulation after 6 and 10 days (68 and 179% after 6 days with A2C at 25 and 50 μM, respectively, and 111% with T4C added at 100 μM). Induction of the proline cycle increased the AQ content after 6 days (~40% for 50 μM A2C and 100 μM T4C). Whereas A2C (50 μM) increased only AQ production, T4C also enhanced total phenolics. However, no induction of the PPP was observed with any of the treatments. This pathway therefore does not limit the supply of carbon skeletons to secondary metabolic pathways.

  8. Contribution of dietary and loading changes to the effects of suspension on mouse femora

    NASA Technical Reports Server (NTRS)

    Simske, S. J.; Broz, J. J.; Fleet, M. L.; Schmeister, T. A.; Gayles, E. C.; Luttges, M. W.; Spooner, B. S. (Principal Investigator)

    1994-01-01

    The present study assessed the contributions of feeding changes and unloading to the overall measured effects of 2-wk hindlimb (Tail) suspension on the mouse femora. Feeding changes were addressed by considering the effects of matched feeding among suspended and control mice. The effects of hind limb unloading were considered by comparing suspended mice to mice equipped identically (though not suspended) and matched-fed. The feeding and unloading aspects of suspension appear to cause distinctly differing effects on the stereotypic modeling of the femora. Matched-feeding was accompanied by increased resorption surface in comparison to suspended mice, while unloading led to reduced bone formation at the mid-diaphysis of the femora. Reduced mineral content was observed in the bones of suspended mice when compared to the other mice groups, but without increased resorption surface. Thus, the unloading aspects of the antiorthostatic suspension protocol apparently causes reduced formation and mineralization in the femur.

  9. Contribution of dietary and loading changes to the effects of suspension on mouse femora

    NASA Technical Reports Server (NTRS)

    Simske, S. J.; Broz, J. J.; Fleet, M. L.; Schmeister, T. A.; Gayles, E. C.; Luttges, M. W.; Spooner, B. S. (Principal Investigator)

    1994-01-01

    The present study assessed the contributions of feeding changes and unloading to the overall measured effects of 2-wk hindlimb (Tail) suspension on the mouse femora. Feeding changes were addressed by considering the effects of matched feeding among suspended and control mice. The effects of hind limb unloading were considered by comparing suspended mice to mice equipped identically (though not suspended) and matched-fed. The feeding and unloading aspects of suspension appear to cause distinctly differing effects on the stereotypic modeling of the femora. Matched-feeding was accompanied by increased resorption surface in comparison to suspended mice, while unloading led to reduced bone formation at the mid-diaphysis of the femora. Reduced mineral content was observed in the bones of suspended mice when compared to the other mice groups, but without increased resorption surface. Thus, the unloading aspects of the antiorthostatic suspension protocol apparently causes reduced formation and mineralization in the femur.

  10. The effect of short-term antiorthostatic hypokinesia on central and intracardiac hemodynamics and metabolism of a healthy person

    NASA Technical Reports Server (NTRS)

    Katkov, V. Y.; Chesturkhin, V. V.; Zybin, O. K.; Sukhotskiy, S. S.; Abrosimov, S. V.; Utkin, V. N.

    1981-01-01

    The right parts of the heart and the radial artery were catheterized in healthy male volunteers before and 5 days after strict bedrest in antiorthostatic position of the body (-4.5 deg). After immobilization, most values of central circulation showed no essential changes; the only exceptions were indicates characterizing the inotropic myocardial condition. A shift in the direction of acidosis of a mixed character was noted in mixed venous blood, the beta lipoprotein content increased. A decrease in the arteriovenous difference in oxygen was encountered in blood draining from the heart (from the coronary sinus).

  11. Effect of Daily Supine LBNP Exercise on Gastrointestinal Motility During Antiorthostatic Bedrest in Normal Subjects

    NASA Technical Reports Server (NTRS)

    Putcha, Lakshmi; DeKerlegand, D.; Hargens, Alan R. (Technical Monitor)

    1997-01-01

    Space flight alters gastrointestinal (GI) function in general, and GI motility, in particular. This can decrease appetite, affect the body's ability to absorb nutrients, fluids and electrolytes, and contribute to a negative energy balance. Antiorthostatic bed rest (ABR) has been used to simulate microgravity-induced physiological changes in human subjects. The objective of this investigation is to determine if daily supine lower body negative pressure (LBNP) exercise will maintain GI motility at near normal levels during ABR. Eight subjects participated in the study protocol consisting of an ambulatory phase scheduled before bedrest periods and two 14 day bed rest (6 deg head-down tilt) periods, once with and another time without exercise. Supine treadmill running in an LBNP chamber was used for exercise. Mouth-to-cecum transit time (MCTT) of lactulose was measured indirectly using the rise in breath hydrogen level after oral administration of lactulose (20 g) following a standard low-fiber breakfast. GI motility during ambulatory and ABR periods was assessed using MCTT data. Results of this Study indicate that GI motility during ABR without exercise decreased by 45% [MCTT +/- S.E.M. 56.2 +/- 6.0 (Ambulatory); 87.3 +/- 8.3 (ABR)]. Supine LBNP exercise did not significantly alter this reduction in GI motility during ABR [MCTT +/- S.E.M. 81.3 +/- 4.2 (Exercise); 87.3 +/- 8.3 (No Exercise)]. These results suggest that supine LBNP exercise may not be an effective countermeasure for microgravity-induced decrements in GI motility and function.

  12. The influence of antiorthostatic unloading and long gamma-irradiation on rat bone marrow (MSCs)

    NASA Astrophysics Data System (ADS)

    Roe, Maria; Bobyleva, Polina; Shtemberg, Andrey; Buravkova, Ludmila

    With the prospect of long interplanetary spaceflight becoming a real possibility there are some important questions that need to be answered regarding the combined effects of microgravity and long gamma-irradiation.The aim of this study was to evaluate the effects of synchronous antiorthostatic unloading and fractional gamma-irradiation on the functional characteristics of rat bone marrow multipotent stromal cells (MSCs).This experiment was carried out following all rules laid out by the Commission on Bioethics at the SSC RF - IBMP RAS. In this experiment the Wistar rats were kept in an unloaded position for a duration of 30 days. They were also subjected to 6 doses of gamma-radiation on the “GOBO-60” with a source of (137) Cs. The dose rate set to 1 meter 50 sGr / H (Total dose of 3 Gr).The study revealed a significant reduction in the number of colonies (CFU-F) in all cultures from the experimental groups when compared to the control groups. The most significant reduction was observed in the group, which had been subject to combined unloading, and radiation. This result was confirmed by examination of cell cultures during 10 days of growth.We found that the CD45 expression was increased in the groups exposed to radiation. At the same time a reduction in the expression of CD90 was observed during combination of radiation and unloading we found.The experimental groups also differed from the control group showing smaller lipid inclusions and decreased expression of alkaline phosphates in the MSCs. This experiment concluded that the bone marrow MSCs after a combination of unloading and multiple radiation sessions, showed a decrease in proliferation and differentiation potential which could reduce the adaption and reparative capacity of the organism.

  13. Effect of Daily Supine LBNP Exercise on Gastrointestinal Motility During Antiorthostatic Bedrest in Normal Subjects

    NASA Technical Reports Server (NTRS)

    Putcha, Lakshmi; DeKerlegand, D.; Hargens, Alan R. (Technical Monitor)

    1997-01-01

    Space flight alters gastrointestinal (GI) function in general, and GI motility, in particular. This can decrease appetite, affect the body's ability to absorb nutrients, fluids and electrolytes, and contribute to a negative energy balance. Antiorthostatic bed rest (ABR) has been used to simulate microgravity-induced physiological changes in human subjects. The objective of this investigation is to determine if daily supine lower body negative pressure (LBNP) exercise will maintain GI motility at near normal levels during ABR. Eight subjects participated in the study protocol consisting of an ambulatory phase scheduled before bedrest periods and two 14 day bed rest (6 deg head-down tilt) periods, once with and another time without exercise. Supine treadmill running in an LBNP chamber was used for exercise. Mouth-to-cecum transit time (MCTT) of lactulose was measured indirectly using the rise in breath hydrogen level after oral administration of lactulose (20 g) following a standard low-fiber breakfast. GI motility during ambulatory and ABR periods was assessed using MCTT data. Results of this Study indicate that GI motility during ABR without exercise decreased by 45% [MCTT +/- S.E.M. 56.2 +/- 6.0 (Ambulatory); 87.3 +/- 8.3 (ABR)]. Supine LBNP exercise did not significantly alter this reduction in GI motility during ABR [MCTT +/- S.E.M. 81.3 +/- 4.2 (Exercise); 87.3 +/- 8.3 (No Exercise)]. These results suggest that supine LBNP exercise may not be an effective countermeasure for microgravity-induced decrements in GI motility and function.

  14. Effects of acute tilt from orthostatic to head-down antiorthostatic restraint and of sustained restraint on the intra-cerebroventricular pressure in rats.

    PubMed

    Maurel, D; Ixart, G; Barbanel, G; Mekaouche, M; Assenmacher, I

    1996-10-14

    The tail-cast suspension rat model was developed to explore in ground laboratories the physiological effects of some of the stresses prevailing during space flight including and among them those of the headwards body fluid shifts. We recently showed in rats that an acute head-down tilt (45 degrees) from tail-cast orthostatic (OR) to antiorthostatic restraint (AOR) induced within 30 min and for 2 to 4 h an acute stress-like surge in plasma ACTH and corticosterone levels. Considering the proximity of the CRF producing neurons with the 3rd ventricle, we decided to explore the acute and longer-term effects of the OR/AOR tilt on the intra-cerebroventricular pressure (Picv) measured with an indwelling sensor-transmitter catheter stereotaxically implanted in the 3rd ventricle. At 1- or 10-min intervals the unit sent radiotelemetric signals for both Picv and motor activity (MA) to a receiver coupled with an automatic data analyser. The acute AOR-tilt induced within 10 min and for 60 min a 2.5-fold rise in Picv which receded to baseline between 60 and 90 min. During this time, the normally close correlation between Picv and MA was lost, as assessed by Spearman's rank coefficient. In a long-term experimental series we explored the evolution of both Picv and MA in individual rats subjected successively to a 7 day control phase (C). 7 days OR, and 3 days AOR. After the 1-h-long post-tilt rise of the Picv, the mean Picv levels measured for the next 3 days decreased significantly vs. both the preceding OR phase (-30%) and the initial C Phase (-40%). The circadian pattern of the diurnal Picv profile was impaired, as evidenced by a significant fall (i) in the night/day ratio (-25% vs. C). and (ii) even more in the spectral power of the circadian 1 c/24 h frequency (-85% vs. C). The simultaneously recorded MA fluctuations similarly displayed an altered diurnal pattern with a spectral power of the circadian frequency reduced to 7% of controls. However, contrary to the short

  15. Separation and characterization of the aldehydic products of lipid peroxidation stimulated by carbon tetrachloride or ADP-iron in isolated rat hepatocytes and rat liver microsomal suspensions.

    PubMed Central

    Poli, G; Dianzani, M U; Cheeseman, K H; Slater, T F; Lang, J; Esterbauer, H

    1985-01-01

    Carbonyl products were separated and identified in suspensions of rat liver microsomal fractions and in isolated hepatocytes, after stimulation of lipid peroxidation by incubation with the pro-oxidants CCl4 and ADP-iron. The carbonyl products were allowed to react with 2,4-dinitrophenylhydrazine, and the derivatives were extracted and separated by t.l.c. into three zones of non-polar materials, and one fraction of polar derivatives that remained at the origin. Separation of the individual non-polar hydrazones in each zone by h.p.l.c. demonstrated that zone I prepared from microsomal fraction or hepatocytes incubated with CCl4 or ADP-iron contained mainly 4-hydroxyhex-2-enal, 4-hydroxynon-2-enal and 4-hydroxynona-2,5-dienal. Zone III consisted mainly of the alkanals propanal, pentanal and hexanal, the 2-alkenals propenal, pent-2-enal, hex-2-enal, hept-2-enal, oct-2-enal and non-2-enal, the ketones butanone, pentan-2-one and pentan-3-one, and deca-2,4-dienal. Incubation of a microsomal fraction with ADP-iron was much more effective in producing malonaldehyde and other carbonyl products than an incubation with CCl4. Despite such quantitative differences, there were no obvious qualitative differences in the h.p.l.c. spectra obtained from zones I and III. However, the stoichiometric evaluation of fatty acid loss and the production of malonaldehyde and other carbonyls suggests that the pathways of lipid peroxidation triggered by CCl4 and ADP-iron are different. The accumulation of carbonyl products of lipid peroxidation in isolated hepatocytes is strongly affected by their metabolism; in particular, 4-hydroxyalkenals were found to be metabolized very rapidly. Nonetheless, both CCl4 and ADP-iron produced stimulation in the production of malonaldehyde and non-polar carbonyl production. After incubation of rat hepatocytes with CCl4 or ADP-iron it was found that approx. 50% of the total amount of non-polar carbonyls produced during incubation escaped into the external medium

  16. Separation and characterization of the aldehydic products of lipid peroxidation stimulated by carbon tetrachloride or ADP-iron in isolated rat hepatocytes and rat liver microsomal suspensions.

    PubMed

    Poli, G; Dianzani, M U; Cheeseman, K H; Slater, T F; Lang, J; Esterbauer, H

    1985-04-15

    Carbonyl products were separated and identified in suspensions of rat liver microsomal fractions and in isolated hepatocytes, after stimulation of lipid peroxidation by incubation with the pro-oxidants CCl4 and ADP-iron. The carbonyl products were allowed to react with 2,4-dinitrophenylhydrazine, and the derivatives were extracted and separated by t.l.c. into three zones of non-polar materials, and one fraction of polar derivatives that remained at the origin. Separation of the individual non-polar hydrazones in each zone by h.p.l.c. demonstrated that zone I prepared from microsomal fraction or hepatocytes incubated with CCl4 or ADP-iron contained mainly 4-hydroxyhex-2-enal, 4-hydroxynon-2-enal and 4-hydroxynona-2,5-dienal. Zone III consisted mainly of the alkanals propanal, pentanal and hexanal, the 2-alkenals propenal, pent-2-enal, hex-2-enal, hept-2-enal, oct-2-enal and non-2-enal, the ketones butanone, pentan-2-one and pentan-3-one, and deca-2,4-dienal. Incubation of a microsomal fraction with ADP-iron was much more effective in producing malonaldehyde and other carbonyl products than an incubation with CCl4. Despite such quantitative differences, there were no obvious qualitative differences in the h.p.l.c. spectra obtained from zones I and III. However, the stoichiometric evaluation of fatty acid loss and the production of malonaldehyde and other carbonyls suggests that the pathways of lipid peroxidation triggered by CCl4 and ADP-iron are different. The accumulation of carbonyl products of lipid peroxidation in isolated hepatocytes is strongly affected by their metabolism; in particular, 4-hydroxyalkenals were found to be metabolized very rapidly. Nonetheless, both CCl4 and ADP-iron produced stimulation in the production of malonaldehyde and non-polar carbonyl production. After incubation of rat hepatocytes with CCl4 or ADP-iron it was found that approx. 50% of the total amount of non-polar carbonyls produced during incubation escaped into the external medium

  17. Tail suspension increases energy expenditure independently of the melanocortin system in mice.

    PubMed

    Lew, Pei San; Wong, Davie; Yamaguchi, Takafumi; Leckstrom, Arnold; Schwartz, Jacquie; Dodd, Janice G; Mizuno, Tooru M

    2009-10-01

    Space travelers experience anorexia and body weight loss in a microgravity environment, and microgravity-like situations cause changes in hypothalamic activity. Hypothalamic melanocortins play a critical role in the regulation of metabolism. Therefore, we hypothesized that microgravity affects metabolism through alterations in specific hypothalamic signaling pathways, including melanocortin signaling. To address this hypothesis, the microgravity-like situation was produced by an antiorthostatic tail suspension in wild-type and agouti mice, and the effect of tail suspension on energy expenditure and hypothalamic gene expression was examined. Energy expenditure was measured using indirect calorimetry before and during the tail suspension protocol. Hypothalamic tissues were collected for gene expression analysis at the end of the 3 h tail suspension period. Tail suspension significantly increased oxygen consumption, carbon dioxide production, and heat production in wild-type mice. Tail suspension-induced increases in energy expenditure were not attenuated in agouti mice. Although tail suspension did not alter hypothalamic proopiomelanocortin (POMC) and agouti-related protein (AGRP) mRNA levels, it significantly increased hypothalamic interleukin 6 (Il-6) mRNA levels. These data are consistent with the hypothesis that microgravity increases energy expenditure and suggest that these effects are mediated through hypothalamic signaling pathways that are independent of melanocortins, but possibly used by Il-6.

  18. Investigation of Phenolic Acids in Suspension Cultures of Vitis vinifera Stimulated with Indanoyl-Isoleucine, N-Linolenoyl-L-Glutamine, Malonyl Coenzyme A and Insect Saliva

    PubMed Central

    Riedel, Heidi; Akumo, Divine N.; Saw, Nay Min Min Thaw; Smetanska, Iryna; Neubauer, Peter

    2012-01-01

    Vitis vinifera c.v. Muscat de Frontignan (grape) contains various high valuable bioactive phenolic compounds with pharmaceutical properties and industrial interest which are not fully exploited. The focus of this investigation consists in testing the effects of various biological elicitors on a non-morphogenic callus suspension culture of V. vinifera. The investigated elicitors: Indanoyl-isoleucine (IN), N-linolenoyl-L-glutamine (LG), insect saliva (IS) and malonyl coenzyme A (MCoA) were aimed at mimicking the influence of environmental pathogens on plants in their natural habitats and at provoking exogenous induction of the phenylpropanoid pathway. The elicitors’ indanoyl-isoleucine (IN), N-linolenoyl-L-glutamine (LG) and insect saliva (IS), as well as malonyl coenzyme A (MCoA), were independently inoculated to stimulate the synthesis of phenylpropanoids. All of the enhancers positively increased the concentration of phenolic compounds in grape cells. The highest concentration of phenolic acids was detected after 2 h for MCoA, after 48 h for IN and after 24 h for LG and IS respectively. At the maximum production time, treated grape cells had a 3.5-fold (MCoA), 1.6-fold (IN) and 1.5-fold (IS) higher phenolic acid content compared to the corresponding control samples. The HPLC results of grape cells showed two major resveratrol derivatives: 3-O-Glucosyl-resveratrol and 4-(3,5-dihydroxyphenyl)-phenol. Their influences of the different elicitors, time of harvest and biomass concentration (p < 0.0001) were statistically significant on the synthesis of phenolic compounds. The induction with MCoA was found to demonstrate the highest statistical effect corresponding to the strongest stress response within the phenylpropanoid pathway in grape cells. PMID:24957372

  19. Effects of prolonged bedrest in antiorthostatic position on rCBF measured by /sup 133/Xe inhalation technique - effects of clonidine

    SciTech Connect

    Guell, A.; Victor, G.; Bru, A.; Montastruc, P.; Bes, A.

    1981-12-01

    Experiments involving prolonged bedrest in antiorthostatic position were performed in order to simulate cardiovascular changes observed in weightlessness. Six young healthy subjects were placed in strict bedrest in a -4-deg antiorthostatic position for seven days. The rCBF (regional cerebral blood flow) measurements were made by an Xe-133 inhalation method. Three of the subjects received 0.450 mg of clonidine during the experiment. A constant increase in rCBF was observed during the first 12 hours in subjects who did not receive clonidine at the 72nd hour, all values returned to the basal state. These findings agree with the rapid correction of hemodynamic disturbances observed in the first days of weightlessness. In subjects treated with clonidine, the increase in rCBF did not occur.

  20. Rethinking Suspensions

    ERIC Educational Resources Information Center

    Stetson, Frank H.; Collins, Betty J.

    2010-01-01

    The overrepresentation of the Black and Hispanic subgroups in suspension data is a national problem and a troubling issue for schools and school systems across the United States. In Maryland, an analysis of student suspensions by school districts for the 2006-2007 school year revealed disproportionality issues. In 23 of the 24 jurisdictions,…

  1. Rethinking Suspensions

    ERIC Educational Resources Information Center

    Stetson, Frank H.; Collins, Betty J.

    2010-01-01

    The overrepresentation of the Black and Hispanic subgroups in suspension data is a national problem and a troubling issue for schools and school systems across the United States. In Maryland, an analysis of student suspensions by school districts for the 2006-2007 school year revealed disproportionality issues. In 23 of the 24 jurisdictions,…

  2. Regulation of hematopoiesis in rats exposed to antiorthostatic, hypokinetic/hypodynamia. I - Model description

    NASA Technical Reports Server (NTRS)

    Dunn, C. D. R.; Johnson, P. C.; Lange, R. D.; Perez, L.; Nessel, R.

    1985-01-01

    The effect of a 7-day suspension in a jacket and harness with 20-deg head-down tilt on body weight, food and water consumption, and hematological parameters is investigated experimentally in male Sprague-Dawley rats weighing 150-175 g. The results are presented in graphs and compared with those for unsuspended controls and with published data on rats and humans exposed to microgravity in space flight. Suspended rats are found to have reduced red-blood-cell mass, erythropoiesis, plasma volume (leading to temporarily increased hematocrit), body weight, and food and water consumption; rightward-shifted oxyhemoglobin-dissociation curves; and unchanged platelet count, leucocyte count or PHA reactivity, and red-blood-cell shape distribution. Since many of these effects are also seen in space flight, the present experimental model is considered a promising technique for simulating the hematopoietic effects of microgravity at 1 g.

  3. Suspension and Debarment Regulations

    EPA Pesticide Factsheets

    Governmentwide Nonprocurement Suspension and Debarment Guidelines and EPA Implementation. Executive Order 12549 provides for a governmentwide system of nonprocurment (grants and cooperative agreements) debarment and suspension.

  4. Stimulation of de novo synthesis of L-phenylalanine ammonia-lyase in relation to phytoalexin accumulation in Colletotrichum lindemuthianum elicitor-treated cell suspension cultures of french bean (Phaseolus vulgaris).

    PubMed

    Dixon, R A; Lamb, C J

    1979-09-03

    (1) The regulation of the accumulation of the isoflavonoid-derived phytoalexin phaseollin in cell suspension cultures of Dwarf French Bean (Phaseolus vulgaris/ has been investigated. (2) An elicitor preparation from cell walls of Colletotrichum lindemuthianum, the causal agent of anthracnose disease of French bean, caused a marked accumulation of phaseollin in the cultures. The elicitor induced phaseollin accumulation to a level of 60% that obtained with the artificial elicitor autoclaved ribonuclease A and was maximally active at a concentration (weight basis) of at least 50 times lower than required for maximal response to ribonuclease. (3) Elicitor preparations from cell walls of Phytophthora megasperma var. sojae, a fungal pathogen of soybean, and Botrytis cinerea, the common grey mould, were much less effective than the C. lindemuthianum wall-released elicitor. (4) There was a marked but transient increase in the extractable activity of phenylalanine ammonia-lyase, the enzyme catalysing the first reaction in the biosynthesis of phaseollin from L-phenylalanine, in response to the elicitor from C. lindemuthianum. (5) Comparative density labelling with 2H from 2H2O indicated that the elicitor stimulates de novo synthesis of phenylalanine ammonie findings provide the basis of a scheme for elicitor induction of phytoalexin accumulation.

  5. EDITORIAL: Colloidal suspensions Colloidal suspensions

    NASA Astrophysics Data System (ADS)

    Petukhov, Andrei; Kegel, Willem; van Duijneveldt, Jeroen

    2011-05-01

    Special issue in honour of Henk Lekkerkerker's 65th birthday Professor Henk N W Lekkerkerker is a world-leading authority in the field of experimental and theoretical soft condensed matter. On the occasion of his 65th birthday in the summer of 2011, this special issue celebrates his many contributions to science. Henk Lekkerkerker obtained his undergraduate degree in chemistry at the University of Utrecht (1968) and moved to Calgary where he received his PhD in 1971. He moved to Brussels as a NATO fellow at the Université Libre de Bruxelles and was appointed to an assistant professorship (1974), an associate professorship (1977) and a full professorship (1980) in physical chemistry at the Vrije Universiteit Brussel. In 1985 he returned to The Netherlands to take up a professorship at the Van 't Hoff Laboratory, where he has been ever since. He has received a series of awards during his career, including the Onsager Medal (1999) of the University of Trondheim, the Bakhuys Roozeboom Gold Medal (2003) of the Royal Dutch Academy of Arts and Sciences (KNAW), the ECIS-Rhodia European Colloid and Interface Prize (2003), and the Liquid Matter Prize of the European Physical Society (2008). He was elected a member of KNAW in 1996, was awarded an Academy Chair position in 2005, and has held several visiting lectureships. Henk's work focuses on phase transitions in soft condensed matter, and he has made seminal contributions to both the theoretical and experimental aspects of this field. Here we highlight three major themes running through his work, and a few selected publications. So-called depletion interactions may lead to phase separation in colloid-polymer mixtures, and Henk realised that the partitioning of polymer needs to be taken into account to describe the phase behaviour correctly [1]. Colloidal suspensions can be used as model fluids, with the time- and length-scales involved leading to novel opportunities, notably the direct observation of capillary waves at a

  6. Urinary incontinence - retropubic suspension

    MedlinePlus

    ... Marchetti-Krantz (MMK) procedure; Laparoscopic retropubic colposuspension; Needle suspension; Burch colposuspension ... bladder. There are two ways to do retropubic suspension: open surgery or laparoscopic surgery. Either way, surgery ...

  7. Collapsing granular suspensions.

    PubMed

    Kadau, D; Andrade, J S; Herrmann, H J

    2009-11-01

    A 2D contact dynamics model is proposed as a microscopic description of a collapsing suspension/soil to capture the essential physical processes underlying the dynamics of generation and collapse of the system. Our physical model is compared with real data obtained from in situ measurements performed with a natural collapsing/suspension soil. We show that the shear strength behavior of our collapsing suspension/soil model is very similar to the behavior of this collapsing suspension soil, for both the unperturbed and the perturbed phases of the material.

  8. Hydrodynamics of bacterial suspensions

    NASA Astrophysics Data System (ADS)

    Arlt, Jochen; Duncan, William J.; Poon, Wilson C. K.

    2005-08-01

    Suspensions of motile E. coli bacteria serve as a model system to experimentally study the hydrodynamics of active particle suspensions. Colloidal probe particles are localised within a suspension of motile bacteria by use of optical tweezers and their uctuations are monitored. The activity of the bacteria effects the fluctuations of the probe particles and their correlation, revealing information about the hydrodynamics of the suspension. We highlight experimental problems that make the interpretation of 'single probe' experiments (as reported before in literature) diffcult and present some preliminary results for 'dual probe' cross-correlation experiments.

  9. Laser effects on yeast cell suspensions

    NASA Astrophysics Data System (ADS)

    Grigorovici, A.; Despa, Sanda I.; Paunescu, Teodor G.

    1995-03-01

    The aim of this paper is to determine the effects produced by coherent electromagnetic radiation in the ultraviolet and visible range on the growth of a Saccharomyces cerevisiae cell suspension. There were made several experiments in which we used different irradiation parameters (power, irradiation time, wavelength) for pointing out those that produce the stimulation or inhibition of the cellular culture growth. Beyond the modifications that appeared in the culture evolution we investigated other physical and chemical changes induced by the laser light on yeast cell suspensions.

  10. Effect of oral calcium and calcium + fluoride treatments on mouse bone properties during suspension

    NASA Technical Reports Server (NTRS)

    Simske, S. J.; Luttges, M. W.; Allen, K. A.; Spooner, B. S. (Principal Investigator)

    1992-01-01

    The bone effects of oral dosages of calcium chloride with or without supplementary sodium fluoride were assessed in antiorthostatically suspended mice. Two calcium dosages were used to replace half (3.1 mM) or all(6.3 mM) of the dietary calcium lost due to reduced food intake by the suspended mice. Two groups of 6.3 mM CaCl2-treated mice were additionally treated with 0.25 or 2.5 mM NaF. The results indicate that supplementation of the mouse drinking water with calcium salts prevents bone changes induced by short-term suspension, while calcium salts in combination with fluoride are less effective as fluoride dosage increases. However, the calcium supplements change the relationship between the femur mechanical properties and the mineral composition of the bone. Because of this, it appears that oral calcium supplements are effective through a mechanism other than simple dietary supplementation and may indicate a dependence of bone consistency on systemic and local fluid conditions.

  11. Effect of oral calcium and calcium + fluoride treatments on mouse bone properties during suspension

    NASA Technical Reports Server (NTRS)

    Simske, S. J.; Luttges, M. W.; Allen, K. A.; Spooner, B. S. (Principal Investigator)

    1992-01-01

    The bone effects of oral dosages of calcium chloride with or without supplementary sodium fluoride were assessed in antiorthostatically suspended mice. Two calcium dosages were used to replace half (3.1 mM) or all(6.3 mM) of the dietary calcium lost due to reduced food intake by the suspended mice. Two groups of 6.3 mM CaCl2-treated mice were additionally treated with 0.25 or 2.5 mM NaF. The results indicate that supplementation of the mouse drinking water with calcium salts prevents bone changes induced by short-term suspension, while calcium salts in combination with fluoride are less effective as fluoride dosage increases. However, the calcium supplements change the relationship between the femur mechanical properties and the mineral composition of the bone. Because of this, it appears that oral calcium supplements are effective through a mechanism other than simple dietary supplementation and may indicate a dependence of bone consistency on systemic and local fluid conditions.

  12. Research on School Suspension

    ERIC Educational Resources Information Center

    Iselin, Anne-Marie

    2010-01-01

    Schools across the nation report increases in the use of punitive disciplinary methods (e.g., suspension). The need for these disciplinary practices to address serious student misconduct is undisputed. What research has questioned is why some students seem to be suspended more often than others, what effects suspension has on students, and whether…

  13. Suspension Geometry Measuring

    NASA Astrophysics Data System (ADS)

    Kao, M. J.; Yu, C. C.; Chang, H.; Tsung, T. T.; Lin, H. M.

    2006-10-01

    This paper describes the instrumentation and analysis of the Vehicle suspension's electrical signals. It will measure the Vehicle suspensions' Vertical Displacement, Track Change, Camber Angle, Caster Angle Steer Angle and convert physical quantity into electrical signals in a various vehicle load change. With using electrical signals for computer control, the electrical controlled vehicle has brought great convenience, great safety and thoughtful kindness vehicle system in our daily life. It will measure the Vehicle suspensions' Vertical Displacement, Track Change, Camber Angle, Caster Angle Steer Angle and convert physical quantity into electrical signals in a various vehicle load change. The function of a suspension system in an automobile is to improve ride comfort and stability. Advances in electronic control technology, applied to the automobile, can improve those functions. The results show that the photocell can convert the electrical signals of suspension for peripheral communications link between the vehicle driving and the electronic control unit (ECU) employed for processing.

  14. Fragility in dense suspensions

    NASA Astrophysics Data System (ADS)

    Mari, Romain; Cates, Mike

    Dense suspensions can jam under shear when the volume fraction of solid material is large enough. In this work we investigate the mechanical properties of shear jammed suspensions with numerical simulations. In particular, we address the issue of the fragility of these systems, i.e., the type of mechanical response (elastic or plastic) they show when subject to a mechanical load differing from the one applied during their preparation history.

  15. Articulated suspension system

    NASA Technical Reports Server (NTRS)

    Bickler, Donald B. (Inventor)

    1989-01-01

    The invention provides a rough terrain vehicle which maintains a substantially constant weight, and therefore traction, on all wheels, despite one wheel moving considerably higher or lower than the others, while avoiding a very soft spring suspension. The vehicle includes a chassis or body to be supported and a pair of side suspensions at either side of the body. In a six wheel vehicle, each side suspension includes a middle wheel, and front and rear linkages respectively coupling the front and rear wheels to the middle wheel. A body link pivotally connects the front and rear linkages together, with the middle of the body link rising or falling by only a fraction of the rise or fall of any of the three wheels. The body link pivotally supports the middle of the length of the body. A transverse suspension for suspending the end of the body on the side suspensions includes a middle part pivotally connected to the body about a longitudinal axis and opposite ends each pivotally connected to one of the side suspensions along at least a longitudinal axis.

  16. Hybrid superconducting magnetic suspensions

    SciTech Connect

    Tixador, P.; Hiebel, P.; Brunet, Y.

    1996-07-01

    Superconductors, especially high T{sub c} ones, are the most attractive materials to design stable and fully passive magnetic suspensions which have to control five degrees of freedom. The hybrid superconducting magnetic suspensions present high performances and a simple cooling mode. They consist of a permanent magnet bearing, stabilized by a suitable magnet-superconductor structure. Several designs are given and compared in terms of forces and stiffnesses. The design of the magnet bearing plays an important part. The superconducting magnetic bearing participates less in levitation but must provide a high stabilizing stiffness. This is achieved by the magnet configuration, a good material in term of critical current density and field cooling. A hybrid superconducting suspension for a flywheel is presented. This system consists of a magnet thrust bearing stabilized by superconductors interacting with an alternating polarity magnet structure. First tests and results are reported. Superconducting materials are magnetically melt-textured YBaCuO.

  17. Suspension Bridge Structural Systems: Cable Suspension & Anchorage; Warren Stiffening ...

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

    Suspension Bridge Structural Systems: Cable Suspension & Anchorage; Warren Stiffening Truss; Upper & Lower Decks; Assembled System - San Francisco Oakland Bay Bridge, Spanning San Francisco Bay, San Francisco, San Francisco County, CA

  18. Magnetic Suspension Technology Workshop

    NASA Technical Reports Server (NTRS)

    Keckler, Claude R. (Editor); Groom, Nelson J. (Editor); Britcher, Colin P. (Editor)

    1993-01-01

    In order to identify the state of magnetic suspension technology in such areas as rotating systems, pointing of experiments or subsystems, payload isolation, and superconducting materials, a workshop on Magnetic Suspension Technology was held at the Langley Research Center in Hampton, Virginia, on 2-4 Feb. 1988. The workshop included five technical sessions in which a total of 24 papers were presented. The technical sessions covered the areas of pointing, isolation, and measurement, rotating systems, modeling and control, and superconductors. A list of attendees is provided.

  19. Modeling of concentrated suspensions

    NASA Astrophysics Data System (ADS)

    van den Brule, B. H. A. A.; Jongschaap, R. J. J.

    1991-03-01

    The constitutive equation of a concentrated suspension of spherical particles in a Newtonian medium is derived. To this end the method of local volume averaging is employed. To calculate the contribution of the particles to the stress tensor it is assumed that the stress generated in the interstitial holes between the particles is negligible compared to the stress generated in !he narrow gaps separating the particles. The use of the resulting expression is demonstrated with two examples on a cubical arrangement of particles: pure shear and simple shear. Furthermore, the validity of the lubrication approximation employed in this work is checked against the results derived by Nunan and Keller for periodic suspensions.

  20. Suspension device for automobile

    SciTech Connect

    Ohtageki, S.; Wada, S.; Hata, Y.; Takizawa, S.; Maruyama, M.

    1986-11-25

    A suspension device is described for an automobile, comprising a pressure source, an electromagnetic valve for transmitting and breaking fluid pressure of the pressure source, and an actuator for converting the fluid pressure transmitted through the electromagnetic valve into a kinetic movement. It also comprises a rod turned by the movement of the actuator, a shock absorber having a damping force changed by turning the rod and a suspension spring having a spring constant changed by the turning rod. The pressure source is used in common to a pressure source for a road clearance adjusting device for adjusting a change in road clearance.

  1. Bacterial suspensions under flow

    NASA Astrophysics Data System (ADS)

    Clement, Eric; Lindner, Anke; Douarche, Carine; Auradou, Harold

    2016-11-01

    Fluids laden with motile bacteria enter in the category of active matter, a new field currently developing at the convergence of biology, hydrodynamics and statistical physics. Such suspensions were shown recently to exhibit singular macroscopic transport properties. In this paper we review some recent results, either theoretical or experimental, on the active fluid rheology. We focus principally on bacteria suspensions and the objective is to provide the basis for understanding the emergence of the singular constitutive relations characterizing the macroscopic transport properties of such an active fluid under flow.

  2. Keep solids in suspension

    SciTech Connect

    Gladki, H.Z.

    1997-10-01

    Mixing is an important operation in the CPI. It is not synonymous with agitation. Mixing is a random distribution into and through one another of two or more initially separate phases. Within that broad definition is the important specialty area of liquid-solid dispersion. This paper addresses the dispersion of solids in lower concentrations that don`t affect the rheological properties of the fluid. The just suspended condition represents the lowest grade of complete suspension, but this level of agitation is the most efficient for solids-liquid agitation. Higher mixing speeds waste energy. Undersized mixers need replacing. The top-entering mixer has a long history in the CPI and the environmental area. Many suspension studies were run with this type. These papers result in empirical correlations for just suspension conditions to scale up from laboratory measurement. Variables considered are the agitation speed, liquid and solids physical properties, solids concentration, system geometry and impeller type. Lately, submersible mixers are becoming more popular, but there are no published sizing methods. This article will explain how to define the critical hydraulic conditions in the tank to reach just solids suspension for a submersible agitator of the type described here as FJFA (Free Jet Flow Agitator).

  3. Flywheel Magnetic Suspension Developments

    NASA Technical Reports Server (NTRS)

    Palazzolo, Alan; Kenny, Andrew; Sifford, Curtiss; Thomas, Erwin; Bhuiyan, Mohammad; Provenza, Andrew; Kascak, Albert; Montague, Gerald; Lei, Shuliang; Kim, Yeonkyu; Sun, Guangyoung; Chon, ChonHee; Tucker, Randy; Preuss, Jason; Li, Ming; Minihan, Thomas

    2002-01-01

    The paper provides an overview of many areas of the flywheel magnetic suspension (MS) R&D being performed at the Texas A&M Vibration Control and Electromechanics Lab (TAMU-VCEL). This includes system response prediction, actuator optimization and redundancy, controller realizations and stages, sensor enhancements and backup bearing reliability.

  4. Crewbot Suspension Design

    NASA Technical Reports Server (NTRS)

    Wood, Nathan A.

    2005-01-01

    Planetary Surface Robot Work Crews (RWC) represent a new class of construction robots for future deployment in planetary exploration. Rovers currently being used for the RWC platform lack the load carrying capabilities required in regular work. Two new rovers, dubbed CrewBots, being designed in JPL's Planetary Robotics Lab specifically for RWC applications greatly increase the load carrying capabilities of the platform. A major component of the rover design was the design of the rocker type suspension, which increases rover mobility. The design of the suspension for the Crewbots departed from the design of recent rovers. While many previous rovers have used internal bevel gear differentials, the increased load requirements of the Crewbots calls for a more robust system. The solution presented is the use of an external modified three-bar, slider-linkage, rocker-style suspension that increases the moment arm of the differential. The final product is a suspension system capable of supporting the extreme loading cases the RWC platform presents, without consuming a large portion of the Crewbots' internal space.

  5. Alternatives to Student Suspension

    ERIC Educational Resources Information Center

    Robinett, David

    2012-01-01

    Seven years ago, James A. Garfield High School in East Los Angeles set a school record with 613 student suspensions, out of a total enrollment of 5,000 students. The school, made famous by the 1988 film "Stand and Deliver", was no stranger to the high rates of student discipline all too common within the Los Angeles Unified School…

  6. Automobile suspension system

    SciTech Connect

    Kumagai, N.; Tatemoto, M.; Oshima, S.; Maruyama, M.; Wada, S.; Shimomura, S.

    1986-11-25

    A suspension system is described for an automobile comprising a suspension having variable characteristics changeable according to an operating condition of the vehicle, and at least one of a vehicle speed sensor means for detecting the speed of the vehicle. It also comprises a steering wheel sensor means for detecting the steering condition of the vehicle's steering wheel, a vehicle height sensor means for detecting the height of the vehicle body relative to the vehicle wheel or the vehicle wheel axle and corresponding to a plurality of classified height ranges, and an acceleration sensor means for detecting the acceleration of the vehicle. The system further comprises: a first means for detecting commencement of the turning movement of the vehicle on the basis of at least one of the output signals from the vehicle speed sensor means, the steering wheel sensor means, the vehicle height sensor means, and the acceleration sensor means. The first means is also for changing the suspension characteristic to a first value representing a hard condition; and a second means for detecting completion of the turning movement of the vehicle on the basis of at least one of the output signals from the vehicle speed sensor means, the steering wheel sensor means, the vehicle height sensor means, and the acceleration sensor means. The second means is also for changing the suspension characteristic to a second value representing a soft condition.

  7. Clustering in Bubble Suspensions

    NASA Astrophysics Data System (ADS)

    Zenit, Roberto

    2000-11-01

    A monidisperse bubble suspension is studied experimentally for the limit in which the Weber number is small and the Reynolds number is large. For this regime the suspension can be modeled using potential flow theory to describe the dynamics of the interstitial fluid. Complete theoretical descriptions have been composed (Spelt and Sangani, 1998) to model the behavior of these suspensions. Bubble clustering is a natural instability that arises from the potential flow considerations, in which bubbles tend to align in horizontal rafts as they move upwards. The appearance of bubble clusters was recently corroborated experimentally by Zenit et al. (2000), who found that although clusters did appear, their strength was not as strong as the predictions. Experiments involving gravity driven shear flows are used to explain the nature of the clustering observed in these type of flows. Balances of the bubble phase pressure (in terms of a calculated diffusion coefficient) and the Maxwell pressure (from the potential flow description) are presented to predict the stability of the bubble suspension. The predictions are compared with experimental results.

  8. Viscosity of colloidal suspensions

    SciTech Connect

    Cohen, E.G.D.; Schepper, I.M. de

    1995-12-31

    Simple expressions are given for the effective Newtonian viscosity as a function of concentration as well as for the effective visco-elastic response as a function of concentration and imposed frequency, of monodisperse neutral colloidal suspensions over the entire fluid range. The basic physical mechanisms underlying these formulae are discussed. The agreement with existing experiments is very good.

  9. Simulations of flexible fiber suspensions

    Treesearch

    Emilio J. Tozzi; Daniel J. Klingenberg; C. Tim Scott; Pasi Miettinen

    2005-01-01

    Fiber-level simulations are employed to probe the relationships between various properties and macroscopic behavior of flexible fiber suspensions. Issues addressed include flocculation, suspension rheology, and handsheet formation and testing. Results show that such simulations can be useful tools for understanding the factors that control the behavior of suspensions...

  10. In-School Suspension Program.

    ERIC Educational Resources Information Center

    Thomas County Schools, Thomasville, GA.

    The in-school suspension program (ISS) for grades 6-12 in Thomas County, Georgia, is described in this report. The program retains students in school, offers individual help, and provides the opportunity to stay on task. During the suspension period, students are placed in individualized carrels in the suspension center and must complete…

  11. Space applications of diamagnetic suspensions

    NASA Technical Reports Server (NTRS)

    Pelrine, Ronald E.

    1992-01-01

    Conventional noncontact magnetic suspensions require power and sensor feedback to maintain stability of the levitated object. Magnetic suspensions using superconductors require neither power nor feedback for stability but must be maintained at low temperatures. This paper discusses a little known type of magnetic bearing that does not require power, sensor feedback, or cooling: diamagnetic suspension. While the bearing pressure for diamagnetic suspensions is typically limited to 1 g/sq cm, their simplicity, environmental tolerances, and wide range of material choices suggest that they may be useful for a number of space applications. This paper discusses the fundamentals of diamagnetic suspensions as well as their potential space applications.

  12. Articulated Suspension Without Springs

    NASA Technical Reports Server (NTRS)

    Bickler, Donald B.

    1990-01-01

    Wheels negotiate bumps and holes with minimal tilting of vehicle body. In new suspension, wheel climbs obstacle as high as 1 1/2 times its diameter without excessive tilting of chassis. Provides highly stable ride over rough ground for such vehicles as wheelchairs, military scout cars, and police and fire robots. System of levers distributes weight to wheels. Sized to distribute equal or other desired portions of load among wheels.

  13. Articulated Suspension Without Springs

    NASA Technical Reports Server (NTRS)

    Bickler, Donald B.

    1990-01-01

    Wheels negotiate bumps and holes with minimal tilting of vehicle body. In new suspension, wheel climbs obstacle as high as 1 1/2 times its diameter without excessive tilting of chassis. Provides highly stable ride over rough ground for such vehicles as wheelchairs, military scout cars, and police and fire robots. System of levers distributes weight to wheels. Sized to distribute equal or other desired portions of load among wheels.

  14. Stress in dilute suspensions

    NASA Technical Reports Server (NTRS)

    Passman, Stephen L.

    1989-01-01

    Generally, two types of theory are used to describe the field equations for suspensions. The so-called postulated equations are based on the kinetic theory of mixtures, which logically should give reasonable equations for solutions. The basis for the use of such theory for suspensions is tenuous, though it at least gives a logical path for mathematical arguments. It has the disadvantage that it leads to a system of equations which is underdetermined, in a sense that can be made precise. On the other hand, the so-called averaging theory starts with a determined system, but the very process of averaging renders the resulting system underdetermined. A third type of theory is proposed in which the kinetic theory of gases is used to motivate continuum equations for the suspended particles. This entails an interpretation of the stress in the particles that is different from the usual one. Classical theory is used to describe the motion of the suspending medium. The result is a determined system for a dilute suspension. Extension of the theory to more concentrated systems is discussed.

  15. Dense Suspension Splash

    NASA Astrophysics Data System (ADS)

    Zhang, Wendy; Dodge, Kevin M.; Peters, Ivo R.; Ellowitz, Jake; Klein Schaarsberg, Martin H.; Jaeger, Heinrich M.

    2014-03-01

    Upon impact onto a solid surface at several meters-per-second, a dense suspension plug splashes by ejecting liquid-coated particles. We study the mechanism for splash formation using experiments and a numerical model. In the model, the dense suspension is idealized as a collection of cohesionless, rigid grains with finite surface roughness. The grains also experience lubrication drag as they approach, collide inelastically and rebound away from each other. Simulations using this model reproduce the measured momentum distribution of ejected particles. They also provide direct evidence supporting the conclusion from earlier experiments that inelastic collisions, rather than viscous drag, dominate when the suspension contains macroscopic particles immersed in a low-viscosity solvent such as water. Finally, the simulations reveal two distinct routes for splash formation: a particle can be ejected by a single high momentum-change collision. More surprisingly, a succession of small momentum-change collisions can accumulate to eject a particle outwards. Supported by NSF through its MRSEC program (DMR-0820054) and fluid dynamics program (CBET-1336489).

  16. The Tail Suspension Test

    PubMed Central

    Terrillion, Chantelle E.; Piantadosi, Sean C.; Bhat, Shambhu; Gould, Todd D.

    2012-01-01

    The tail-suspension test is a mouse behavioral test useful in the screening of potential antidepressant drugs, and assessing of other manipulations that are expected to affect depression related behaviors. Mice are suspended by their tails with tape, in such a position that it cannot escape or hold on to nearby surfaces. During this test, typically six minutes in duration, the resulting escape oriented behaviors are quantified. The tail-suspension test is a valuable tool in drug discovery for high-throughput screening of prospective antidepressant compounds. Here, we describe the details required for implementation of this test with additional emphasis on potential problems that may occur and how to avoid them. We also offer a solution to the tail climbing behavior, a common problem that renders this test useless in some mouse strains, such as the widely used C57BL/6. Specifically, we prevent tail climbing behaviors by passing mouse tails through a small plastic cylinder prior to suspension. Finally, we detail how to manually score the behaviors that are manifested in this test. PMID:22315011

  17. Clay-cement suspensions - rheological and functional properties

    NASA Astrophysics Data System (ADS)

    Wojcik, L.; Izak, P.; Mastalska-Poplawska, J.; Gajek, M.

    2017-01-01

    The piping erosion in soil is highly unexpected in civil engineering. Elimination of such damages is difficult, expensive and time-consuming. One of the possibility is the grouting method. This method is still developed into direction of process automation as well as other useful properties of suspensions. Main way of modernization of the grouting method is connected it with rheology of injection and eventuality of fitting them to specific problems conditions. Very popular and useful became binders based on modified clays (clay-cement suspensions). Important principle of efficiency of the grouting method is using of time-dependent pseudothixotropic properties of the clay-cement suspensions. The pseudo-rheounstability aspect of the suspensions properties should be dedicated and fitted to dynamic changes of soil conditions destructions. Whole process of the modification of the suspension rheology is stimulated by the specific agents. This article contains a description of practical aspects of the rheological parameters managing of the clay-cement suspensions, dedicated to the building damages, hydrotechnic constructions etc.

  18. Novel oral suspensions: a review.

    PubMed

    Kathpalia, Harsha; Phadke, Chetan

    2014-01-01

    An oral pharmaceutical suspension has been one of the most favorable dosage forms for pediatric and geriatric patients or patients unable to tolerate solid dosage forms. The liquid form is preferred because of the ease of swallowing and flexibility in the administration of doses. This emerging area of suspensions as applied to the pharmaceutical field are discussed in the current article enlightening the vision of the readers towards pharmaceutical formulations including nanosuspensions, non-aqueous suspensions and modified release suspensions. The emphasis in the article focuses on the essential principles involved in the process of formation of different types of suspensions and their applications, since novel oral suspensions have potential to provide various strategy systems.

  19. Controls of maglev suspension systems

    SciTech Connect

    Cai, Y.; Zhu, S.; Chen, S.S.; Rote, D.M.

    1993-06-01

    This study investigates alternative control designs of maglev vehicle suspension systems. Active and semi-active control law designs are introduced into primary and secondary suspensions of maglev vehicles. A one-dimensional vehicle with two degrees of freedom, to simulate the German Transrapid Maglev System, is used for suspension control designs. The transient and frequency responses of suspension systems and PSDs of vehicle accelerations are calculated to evaluate different control designs. The results show that active and semi-active control designs indeed improve the response of vehicle and provide an acceptable ride comfort for maglev systems.

  20. Effective Viscosity of Microswimmer Suspensions

    NASA Astrophysics Data System (ADS)

    Rafaï, Salima; Jibuti, Levan; Peyla, Philippe

    2010-03-01

    The measurement of a quantitative and macroscopic parameter to estimate the global motility of a large population of swimming biological cells is a challenge. Experiments on the rheology of active suspensions have been performed. Effective viscosity of sheared suspensions of live unicellular motile microalgae (Chlamydomonas Reinhardtii) is far greater than for suspensions containing the same volume fraction of dead cells. In addition, suspensions show shear thinning behavior. We relate these macroscopic measurements to the orientation of individual swimming cells under flow and discuss our results in the light of several existing models.

  1. Effective viscosity of microswimmer suspensions.

    PubMed

    Rafaï, Salima; Jibuti, Levan; Peyla, Philippe

    2010-03-05

    The measurement of a quantitative and macroscopic parameter to estimate the global motility of a large population of swimming biological cells is a challenge. Experiments on the rheology of active suspensions have been performed. Effective viscosity of sheared suspensions of live unicellular motile microalgae (Chlamydomonas Reinhardtii) is far greater than for suspensions containing the same volume fraction of dead cells. In addition, suspensions show shear thinning behavior. We relate these macroscopic measurements to the orientation of individual swimming cells under flow and discuss our results in the light of several existing models.

  2. 20 CFR 416.1320 - Suspensions; general.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Suspensions; general. 416.1320 Section 416..., BLIND, AND DISABLED Suspensions and Terminations § 416.1320 Suspensions; general. (a) When suspension is proper. Suspension of benefit payments is required when a recipient is alive but no longer meets...

  3. Magnetic Suspension Technology Development

    NASA Technical Reports Server (NTRS)

    Britcher, Colin

    1998-01-01

    This Cooperative Agreement, intended to support focused research efforts in the area of magnetic suspension systems, was initiated between NASA Langley Research Center (LaRC) and Old Dominion University (ODU) starting January 1, 1997. The original proposal called for a three-year effort, but funding for the second year proved to be unavailable, leading to termination of the agreement following a 5-month no-cost extension. This report covers work completed during the entire 17-month period of the award. This research built on work that had taken place over recent years involving both NASA LARC and the Principal Investigator (PI). The research was of a rather fundamental nature, although specific applications were kept in mind at all times, such as wind tunnel Magnetic Suspension and Balance Systems (MSBS), space payload pointing and vibration isolation systems, magnetic bearings for unconventional applications, magnetically levitated ground transportation and electromagnetic launch systems. Fundamental work was undertaken in areas such as the development of optimized magnetic configurations, analysis and modelling of eddy current effects, control strategies for magnetically levitated wind tunnel models and system calibration procedures. Despite the termination of this Cooperative Agreement, several aspects of the research work are currently continuing with alternative forms of support.

  4. Dense suspension splash

    NASA Astrophysics Data System (ADS)

    Dodge, Kevin M.; Peters, Ivo R.; Ellowitz, Jake; Schaarsberg, Martin H. Klein; Jaeger, Heinrich M.; Zhang, Wendy W.

    2014-11-01

    Impact of a dense suspension drop onto a solid surface at speeds of several meters-per-second splashes by ejecting individual liquid-coated particles. Suppression or reduction of this splash is important for thermal spray coating and additive manufacturing. Accomplishing this aim requires distinguishing whether the splash is generated by individual scattering events or by collective motion reminiscent of liquid flow. Since particle inertia dominates over surface tension and viscous drag in a strong splash, we model suspension splash using a discrete-particle simulation in which the densely packed macroscopic particles experience inelastic collisions but zero friction or cohesion. Numerical results based on this highly simplified model are qualitatively consistent with observations. They also show that approximately 70% of the splash is generated by collective motion. Here an initially downward-moving particle is ejected into the splash because it experiences a succession of low-momentum-change collisions whose effects do not cancel but instead accumulate. The remainder of the splash is generated by scattering events in which a small number of high-momentum-change collisions cause a particle to be ejected upwards. Current Address: Physics of Fluids Group, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.

  5. 48 CFR 209.407 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Suspension. 209.407... OF DEFENSE ACQUISITION PLANNING CONTRACTOR QUALIFICATIONS Debarment, Suspension, and Ineligibility 209.407 Suspension....

  6. Flow properties of concentrated suspensions

    NASA Technical Reports Server (NTRS)

    Hattori, K.; Izumi, K.

    1984-01-01

    The viscosity and flow behavior of a concentrated suspension, with special emphasis on fresh concrete containing a superplasticizer, is analyzed according to Newton's law of viscosity. The authors interpreted Newton's law in a new way, and explain non-Newton flow from Newton's law. The outline of this new theory is given. Viscosity of suspensions, and the effect of dispersants are analyzed.

  7. Diesel Technology: Steering and Suspension.

    ERIC Educational Resources Information Center

    Miller, Roger; Scarberry, Terry; Tesch, Carl; Kellum, Mary

    Competency-based teacher and student materials on steering and suspension are provided for a diesel technology curriculum. Eleven units of instruction cover the following topics: chassis, tires, and wheels; steering; and suspension. The materials are based on the curriculum-alignment concept of first stating the objectives, then developing…

  8. Diesel Technology: Steering and Suspension.

    ERIC Educational Resources Information Center

    Miller, Roger; Scarberry, Terry; Tesch, Carl; Kellum, Mary

    Competency-based teacher and student materials on steering and suspension are provided for a diesel technology curriculum. Eleven units of instruction cover the following topics: chassis, tires, and wheels; steering; and suspension. The materials are based on the curriculum-alignment concept of first stating the objectives, then developing…

  9. Physics of colloidal suspensions

    NASA Astrophysics Data System (ADS)

    Huang, Jiping

    Colloidal suspensions are complex fluids that consist of mesoscopic particles suspended in a solvent, e.g. water, oil, etc. In this thesis, the objective is to investigate the four aspects of colloidal suspensions: electrorotation, dielectrophoresis, dielectric dispersion spectrum, and nonlinear alternating current (AC) response. The traditional theories failed to fit the recent experimental data, and hence, for the purpose of a better fitting, we aim to develop new theories. In addition, our theories also predicted some new phenomena which are expected to be verified in experiments. Electrorotation has been increasingly employed as a sensitive tool for non-invasive studies of a broad variety of microparticles, ranging from living cells to spores and seeds, as well as synthetic materials. In order to analyze the abundant experimental data, we extend here the existing theory by taking into account crucial elements, such as inhomogeneities, multipolar interactions, nonspherical shapes as well as many-body (local-field) effects. Good agreement is shown between our theoretical results and the experimental data. Dielectrophoresis is typically used for micromanipulation and separation of biological cellular size particles, and it has recently been successfully applied to submicron size particles as well. Specific applications include diverse problems in medicine, colloidal science and nanotechnology. To analyze the recent experimental observations, we present a theory which includes the effects of both charging and multipolar interactions. Our theoretical results are favorably compared with the recent experimental observations. Recent experiments revealed that the dielectric dispersion spectrum of fission yeast cells in a suspension was mainly composed of two sub-dispersions. The low-frequency sub-dispersion depended on the cell length, while the high-frequency one was independent of it. However, the existing theory does not fit the experimental data. Hence, we here put

  10. Suspension Needn't Arrest Learning.

    ERIC Educational Resources Information Center

    Seegrist, Ruth

    1985-01-01

    An inschool suspension program at a Pennsylvania school district is described. Students spend suspension time completing classroom assignments under strict teacher supervision in detention halls. (TE)

  11. Electrorheology of nanofiber suspensions

    PubMed Central

    2011-01-01

    Electrorheological (ER) fluid, which can be transformed rapidly from a fluid-like state to a solid-like state under an external electric field, is considered to be one of the most important smart fluids. However, conventional ER fluids based on microparticles are subjected to challenges in practical applications due to the lack of versatile performances. Recent researches of using nanoparticles as the dispersal phase have led to new interest in the development of non-conventional ER fluids with improved performances. In this review, we especially focus on the recent researches on electrorheology of various nanofiber-based suspensions, including inorganic, organic, and inorganic/organic composite nanofibers. Our goal is to highlight the advantages of using anisotropic nanostructured materials as dispersal phases to improve ER performances. PMID:21711790

  12. Tubing suspension system

    SciTech Connect

    Berner, P. C.; Brickman, E. L.

    1985-12-31

    A tubing suspension system for undersea well production operations employs a nonoriented tubing hanger having an inner body for supporting a tubing string and a landing collar for supporting the tubing hanger on a wellhead casing. The tubing hanger includes three co-operating concentric sleeve assemblies which are employed to lock and seal the tubing hanger to the wellhead housing. The outer sleeve assembly includes a locking actuator and a dual seal assembly and is separately retrievable from the remainder of the hanger assmebly. A nonorienting hydraulic set running tool is employed to run the tubing hanger, set the seals, lock the tubing hanger to the wellhead casing, retrieve either the outer sleeve assembly or the entire tubing hanger. The running tool includes a hydraulically controlled actuating sleeve which carries a latch dog assembly which locks with the tubing hanger.

  13. Dielectric Constant of Suspensions

    NASA Astrophysics Data System (ADS)

    Mendelson, Kenneth S.; Ackmann, James J.

    1997-03-01

    We have used a finite element method to calculate the dielectric constant of a cubic array of spheres. Extensive calculations support preliminary conclusions reported previously (K. Mendelson and J. Ackmann, Bull. Am. Phys. Soc. 41), 657 (1996).. At frequencies below 100 kHz the real part of the dielectric constant (ɛ') shows oscillations as a function of the volume fraction of suspension. These oscillations disappear at low conductivities of the suspending fluid. Measurements of the dielectric constant (J. Ackmann, et al., Ann. Biomed. Eng. 24), 58 (1996). (H. Fricke and H. Curtis, J. Phys. Chem. 41), 729 (1937). are not sufficiently sensitive to show oscillations but appear to be consistent with the theoretical results.

  14. Suspension device for automobile

    SciTech Connect

    Maruyama, M.; Tatemoto, M.; Takada, H.; Harara, M.; Wada, S.; Shimomura, S.; Kumagai, N.; Takizawa, S.

    1987-03-10

    A suspension device is described for an automobile, comprising: a shock absorber provided with a damping force change-over mechanism; sensor means including means for detecting horizontal and vertical vibration of the vehicle body; and control device which detects a sustaining time period of an output of the sensor means exceeding a determination value. The control device outputs a change-over for changing a damping force of the shock absorber to a large value only when the sustaining time period exceeds a predetermined time period. It also outputs a signal for maintaining the damping force of the shock absorber to be a large value for a predetermined time period even through the output of the sensor disappears.

  15. Suspension for vehicle

    SciTech Connect

    Buma, S.

    1987-03-31

    A suspension system is described for a vehicle, comprising: a shock absorber provided with a tube, a piston partitioning the interior of the tube into two liquid chambers and a piston rod connected to the piston and having a bypass path for affording communication between the two liquid chambers; a control shaft disposed in the piston rod of the shock absorber to open and close the bypass path; a support for coupling the piston rod to a car body and provided with a rigid valve base connected to the piston rod and having a hole in which a valve body is disposed and an elastic bushing disposed radially outward of and secured fixedly to the valve base. The bush is connected to the car body and has fluid chambers; the valve body being disposed in the hole of the valve base to afford and interrupt communication between the fluid chambers; and at least one actuator for operating the control shaft and valve body.

  16. Comparison of the Oxygen Exchange between Photosynthetic Cell Suspensions and Detached Leaves of Euphorbia characias L

    PubMed Central

    Carrier, Patrick; Chagvardieff, Pierre; Tapie, Pierre

    1989-01-01

    Using a mass-spectrometric 16O2/18O2-isotope technique, we compared the nature and the relative importance of oxygen exchange in photomixotrophic (PM) and photoautotrophic (PA) suspensions of Euphorbia characias L. with those in intact leaves of the same species. Young and mature leaves, dividing and nondividing cell suspensions were characterized in short-term experiments. On chlorophyll basis, the gross photosynthetic activities at CO2 saturating concentration of PA and PM suspensions varied little from those of leaves. On dry weight basis, gross photosynthesis of PA suspensions was equal to that of leaves because of their similar chlorophyll content. This was not the case in PM suspensions where gross photosynthesis was lower and largely varied during the growth cycle. The CO2 compensation point of PA cells (155-265 parts per million) was much higher than that of leaves (50-80 ppm). Oxygen uptakes were analyzed in terms of mitochondrial respiration, photorespiration and light stimulation of oxygen uptake (LSOU), often identified to Mehlertype reactions. In PA and PM suspensions, mitochondrial respiration rates were higher than in leaves by a factor of 1.5 to 4.5. In PM suspensions, photorespiration and LSOU were observed only in nondividing cells. Photorespiration and LSOU rates were comparable in PA suspensions and leaves. Our results demonstrate that photorespiration of PA suspensions has not been affected by the 2% CO2 concentration imposed during 2 years of culture. Images Figure 1 PMID:16667114

  17. A simple hindlimb suspension apparatus

    NASA Technical Reports Server (NTRS)

    Park, E.; Schultz, E.

    1993-01-01

    This paper describes the assembly of a simple, inexpensive apparatus for application of the hindlimb suspension model to studies of the effects of unloading on mammalian physiology. Construction of a cage and suspension assembly is described using materials that can be obtained from most hardware stores. The design is kept simple for easy assembly and disassembly to facilitate cleaning and storage. The suspension assembly allows the animals full access to all portions of the floor area and provides an effective environment to study the effects of unloading.

  18. A simple hindlimb suspension apparatus

    NASA Technical Reports Server (NTRS)

    Park, E.; Schultz, E.

    1993-01-01

    This paper describes the assembly of a simple, inexpensive apparatus for application of the hindlimb suspension model to studies of the effects of unloading on mammalian physiology. Construction of a cage and suspension assembly is described using materials that can be obtained from most hardware stores. The design is kept simple for easy assembly and disassembly to facilitate cleaning and storage. The suspension assembly allows the animals full access to all portions of the floor area and provides an effective environment to study the effects of unloading.

  19. Unifying suspension and granular rheology.

    PubMed

    Boyer, François; Guazzelli, Élisabeth; Pouliquen, Olivier

    2011-10-28

    Using an original pressure-imposed shear cell, we study the rheology of dense suspensions. We show that they exhibit a viscoplastic behavior similarly to granular media successfully described by a frictional rheology and fully characterized by the evolution of the friction coefficient μ and the volume fraction ϕ with a dimensionless viscous number I(v). Dense suspension and granular media are thus unified under a common framework. These results are shown to be compatible with classical empirical models of suspension rheology and provide a clear determination of constitutive laws close to the jamming transition.

  20. [Influence of polyethylene oxide Polyox WSR-301 on the pressure in mesenteric arterial microvessels in rats pre-adapted to anti-orthostatic states].

    PubMed

    Grigorian, S S; Sokolova, I A; Shakhnazarov, A A; Rudneva, R I; Timkina, M I

    1998-01-01

    High-molecular polymers apt to directly influence flow microstructure were tested as a fundamentally new method for correcting microhemodynamics in microgravity. Pressure in the mesenteric arterial microvessels was measured two weeks in rats adapted to the head-down suspension. Intravenous polyethylene oxide (Polyox WSR-301, end-concentration in the order of 2.10(-7) g/ml), reduced the microvascular pressure by 26%, whereas in the control pressure was reduced by only 15%. Systemic arterial pressure showed an equal drop in the groups (by 10 to 11%). These results suggest that the biomechanical agent weakens resistance to the blood flow in the body region where blood supply is impaired by microgravity.

  1. 49 CFR 238.427 - Suspension system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Suspension system. 238.427 Section 238.427... Equipment § 238.427 Suspension system. (a) General requirements. (1) Suspension systems shall be designed to... equipment. (2) Passenger equipment shall meet the safety performance standards for suspension systems...

  2. 49 CFR 238.427 - Suspension system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Suspension system. 238.427 Section 238.427... Equipment § 238.427 Suspension system. (a) General requirements. (1) Suspension systems shall be designed to... equipment. (2) All passenger equipment shall meet the safety performance standards for suspension systems...

  3. 41 CFR 105-68.1015 - Suspension.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false Suspension. 105-68.1015 Section 105-68.1015 Public Contracts and Property Management Federal Property Management Regulations...-GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 105-68.1015 Suspension. Suspension is an...

  4. 41 CFR 105-68.1015 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Suspension. 105-68.1015 Section 105-68.1015 Public Contracts and Property Management Federal Property Management Regulations...-GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 105-68.1015 Suspension. Suspension is an...

  5. 49 CFR 393.207 - Suspension systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... pressure regulator valve shall not allow air into the suspension system until at least 55 psi is in the... pressure. (g) Air suspension exhaust controls. The air suspension exhaust controls must not have the... 49 Transportation 5 2011-10-01 2011-10-01 false Suspension systems. 393.207 Section 393.207...

  6. 2 CFR 182.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 2 Grants and Agreements 1 2010-01-01 2010-01-01 false Suspension. 182.670 Section 182.670 Grants... Suspension. Suspension means an action taken by a Federal agency that immediately prohibits a recipient from... guidance on nonprocurement debarment and suspension (2 CFR part 180, which implements Executive...

  7. 75 FR 60 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-04

    ... Part 64 [Docket ID FEMA-2008-0020; Internal Agency Docket No. FEMA-8111] Suspension of Community... Insurance Program (NFIP), that are scheduled for suspension on the effective dates listed within this rule... floodplain management measures prior to the effective suspension date given in this rule, the suspension...

  8. 45 CFR 1173.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Suspension. 1173.670 Section 1173.670 Public... (FINANCIAL ASSISTANCE) Definitions § 1173.670 Suspension. Suspension means an action taken by a Federal..., subpart 9.4) and the common rule, Government-wide Debarment and Suspension (Nonprocurement),...

  9. 78 FR 17130 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-20

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  10. 49 CFR 32.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Suspension. 32.670 Section 32.670 Transportation... ASSISTANCE) Definitions § 32.670 Suspension. Suspension means an action taken by a Federal agency that...-wide Debarment and Suspension (Nonprocurement), that implements Executive Order 12549 and...

  11. 34 CFR 682.705 - Suspension proceedings.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 3 2010-07-01 2010-07-01 false Suspension proceedings. 682.705 Section 682.705... EDUCATION, DEPARTMENT OF EDUCATION FEDERAL FAMILY EDUCATION LOAN (FFEL) PROGRAM Limitation, Suspension, or....705 Suspension proceedings. (a) Scope. (1) A suspension by the Secretary removes a...

  12. 77 FR 68697 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-16

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  13. 22 CFR 1509.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Suspension. 1509.670 Section 1509.670 Foreign... ASSISTANCE) Definitions § 1509.670 Suspension. Suspension means an action taken by a Federal agency that...-wide Debarment and Suspension (Nonprocurement), that implements Executive Order 12549 and...

  14. 76 FR 5284 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-31

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  15. 78 FR 75485 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-12

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  16. 22 CFR 312.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Suspension. 312.670 Section 312.670 Foreign... § 312.670 Suspension. Suspension means an action taken by a Federal agency that immediately prohibits a... Debarment and Suspension (Nonprocurement), that implements Executive Order 12549 and Executive Order...

  17. 78 FR 57525 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-19

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  18. 78 FR 69001 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-18

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  19. 78 FR 2624 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-14

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  20. 29 CFR 1471.1015 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 4 2010-07-01 2010-07-01 false Suspension. 1471.1015 Section 1471.1015 Labor Regulations Relating to Labor (Continued) FEDERAL MEDIATION AND CONCILIATION SERVICE GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 1471.1015 Suspension. Suspension is an action taken by a...

  1. 15 CFR 29.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Suspension. 29.670 Section 29.670... WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 29.670 Suspension. Suspension means an action taken by a..., subpart 9.4) and the common rule, Government-wide Debarment and Suspension (Nonprocurement),...

  2. 78 FR 65882 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-04

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  3. 78 FR 33989 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-06

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  4. 29 CFR 98.1015 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Suspension. 98.1015 Section 98.1015 Labor Office of the Secretary of Labor GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 98.1015 Suspension. Suspension is an action taken by a suspending official under subpart G of this part that...

  5. 31 CFR 20.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Suspension. 20.670 Section 20.670...-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 20.670 Suspension. Suspension means an action taken..., subpart 9.4) and the common rule, Government-wide Debarment and Suspension (Nonprocurement),...

  6. 77 FR 69564 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-20

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  7. 77 FR 75891 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-26

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  8. 29 CFR 1472.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 4 2010-07-01 2010-07-01 false Suspension. 1472.670 Section 1472.670 Labor Regulations... DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 1472.670 Suspension. Suspension means an... CFR part 9, subpart 9.4) and the common rule, Government-wide Debarment and Suspension...

  9. 28 CFR 83.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Suspension. 83.670 Section 83.670... WORKPLACE (GRANTS) Definitions § 83.670 Suspension. Suspension means an action taken by a Federal agency..., subpart 9.4) and the common rule, Government-wide Debarment and Suspension (Nonprocurement),...

  10. 75 FR 24820 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-06

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  11. 50 CFR 13.27 - Permit suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 1 2010-10-01 2010-10-01 false Permit suspension. 13.27 Section 13.27... GENERAL PERMIT PROCEDURES Permit Administration § 13.27 Permit suspension. (a) Criteria for suspension... Government. Such suspension shall remain in effect until the issuing officer determines that the...

  12. 24 CFR 1710.45 - Suspensions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Suspensions. 1710.45 Section 1710... Suspensions. (a) Suspension notice—prior to effective date. (1) If it appears to the Secretary that a... Secretary shall so advise the developer, by issuing a suspension notice, within a reasonable time after...

  13. 20 CFR 439.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Suspension. 439.670 Section 439.670 Employees... ASSISTANCE) Definitions § 439.670 Suspension. Suspension means an action taken by a Federal agency that...-wide Debarment and Suspension (Nonprocurement), that implements Executive Order 12549 and...

  14. 75 FR 52861 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-30

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  15. 45 CFR 1155.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Suspension. 1155.670 Section 1155.670 Public... ASSISTANCE) Definitions § 1155.670 Suspension. Suspension means an action taken by a Federal agency that...-wide Debarment and Suspension (Nonprocurement), that implements Executive Order 12549 and...

  16. 7 CFR 3021.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Suspension. 3021.670 Section 3021.670 Agriculture... Suspension. Suspension means an action taken by a Federal agency that immediately prohibits a recipient from... Debarment and Suspension (Nonprocurement), that implements Executive Order 12549 and Executive Order...

  17. 48 CFR 2909.407 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Suspension. 2909.407... CONTRACTOR QUALIFICATIONS Debarment, Suspension, and Ineligibility 2909.407 Suspension. (a) The Senior... authorized to make an exception, regarding suspension by another agency suspending official under...

  18. 31 CFR 19.1015 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Suspension. 19.1015 Section 19.1015 Money and Finance: Treasury Office of the Secretary of the Treasury GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 19.1015 Suspension. Suspension is an action taken by a...

  19. 21 CFR 1404.1015 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Suspension. 1404.1015 Section 1404.1015 Food and Drugs OFFICE OF NATIONAL DRUG CONTROL POLICY GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 1404.1015 Suspension. Suspension is an action taken by a suspending official under subpart G...

  20. 78 FR 54766 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-06

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  1. 49 CFR 570.8 - Suspension systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Suspension systems. 570.8 Section 570.8... Pounds or Less § 570.8 Suspension systems. (a) Suspension condition. Ball joint seals shall not be cut or... out from or missing from suspension joints. Radius rods shall not be missing or damaged....

  2. 39 CFR 957.27 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Suspension. 957.27 Section 957.27 Postal Service... SUSPENSION FROM CONTRACTING § 957.27 Suspension. (a) Any firm or individual suspended under chapter 3, section 7 of the Postal Service Purchasing Manual who believes that the suspension has not been...

  3. 77 FR 59764 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-01

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  4. 75 FR 18408 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-12

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  5. 22 CFR 1006.1015 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Suspension. 1006.1015 Section 1006.1015 Foreign Relations INTER-AMERICAN FOUNDATION GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 1006.1015 Suspension. Suspension is an action taken by a suspending official under subpart G of...

  6. 43 CFR 43.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Suspension. 43.670 Section 43.670 Public... WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 43.670 Suspension. Suspension means an action taken by a..., subpart 9.4) and 2 CFR part 180. Suspension of a recipient is a distinct and separate action...

  7. 14 CFR 1267.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Suspension. 1267.670 Section 1267.670... WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 1267.670 Suspension. Suspension means an action taken by a..., subpart 9.4) and the common rule, Government-wide Debarment and Suspension (Nonprocurement),...

  8. 78 FR 5734 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-28

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  9. 77 FR 59762 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-01

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  10. 2 CFR 180.1015 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 2 Grants and Agreements 1 2010-01-01 2010-01-01 false Suspension. 180.1015 Section 180.1015 Grants... Reserved OMB GUIDELINES TO AGENCIES ON GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 180.1015 Suspension. Suspension is an action taken by a suspending official under subpart G of...

  11. 22 CFR 208.1015 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Suspension. 208.1015 Section 208.1015 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 208.1015 Suspension. Suspension is an action taken by a suspending official under subpart G...

  12. 29 CFR 94.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Suspension. 94.670 Section 94.670 Labor Office of the... § 94.670 Suspension. Suspension means an action taken by a Federal agency that immediately prohibits a... Debarment and Suspension (Nonprocurement), that implements Executive Order 12549 and Executive Order...

  13. 7 CFR 3017.1015 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Suspension. 3017.1015 Section 3017.1015 Agriculture... AGRICULTURE GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 3017.1015 Suspension. Suspension is an action taken by a suspending official under subpart G of this part that...

  14. 31 CFR 10.82 - Expedited suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Expedited suspension. 10.82 Section... INTERNAL REVENUE SERVICE Rules Applicable to Disciplinary Proceedings § 10.82 Expedited suspension. (a... suspension. A suspension under this section will commence on the date that written notice of the...

  15. 24 CFR 21.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Suspension. 21.670 Section 21.670... GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (GRANTS) Definitions § 21.670 Suspension. Suspension means an... CFR part 9, subpart 9.4) and the common rule, Government-wide Debarment and Suspension...

  16. 21 CFR 1405.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 9 2010-04-01 2010-04-01 false Suspension. 1405.670 Section 1405.670 Food and... (FINANCIAL ASSISTANCE) Definitions § 1405.670 Suspension. Suspension means an action taken by a Federal..., subpart 9.4) and the common rule, Government-wide Debarment and Suspension (Nonprocurement),...

  17. 77 FR 9856 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-21

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  18. 5 CFR 919.1015 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Suspension. 919.1015 Section 919.1015 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS (CONTINUED) GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 919.1015 Suspension. Suspension is...

  19. 22 CFR 1508.1015 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Suspension. 1508.1015 Section 1508.1015 Foreign Relations AFRICAN DEVELOPMENT FOUNDATION GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT) Definitions § 1508.1015 Suspension. Suspension is an action taken by a suspending official under subpart G...

  20. 22 CFR 210.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Suspension. 210.670 Section 210.670 Foreign... (FINANCIAL ASSISTANCE) Definitions § 210.670 Suspension. Suspension means an action taken by a Federal agency..., subpart 9.4) and the common rule, Government-wide Debarment and Suspension (Nonprocurement),...

  1. 45 CFR 1641.11 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Suspension. 1641.11 Section 1641.11 Public Welfare Regulations Relating to Public Welfare (Continued) LEGAL SERVICES CORPORATION DEBARMENT, SUSPENSION AND REMOVAL OF RECIPIENT AUDITORS Suspension § 1641.11 Suspension. (a) IPAs suspended from providing...

  2. 22 CFR 133.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Suspension. 133.670 Section 133.670 Foreign... ASSISTANCE) Definitions § 133.670 Suspension. Suspension means an action taken by a Federal agency that...-wide Debarment and Suspension (Nonprocurement), that implements Executive Order 12549 and...

  3. 76 FR 34611 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-14

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  4. 22 CFR 1008.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 2 2010-04-01 2010-04-01 true Suspension. 1008.670 Section 1008.670 Foreign... ASSISTANCE) Definitions § 1008.670 Suspension. Suspension means an action taken by a Federal agency that...-wide Debarment and Suspension (Nonprocurement), that implements Executive Order 12549 and...

  5. 45 CFR 630.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Suspension. 630.670 Section 630.670 Public Welfare... DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 630.670 Suspension. Suspension means an action... CFR part 9, subpart 9.4) and the common rule, Government-wide Debarment and Suspension...

  6. 75 FR 80351 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-22

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...), that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  7. 77 FR 53775 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-04

    ... SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility AGENCY...) that are scheduled for suspension on the effective dates listed within this rule because of... measures prior to the effective suspension date given in this rule, the suspension will not occur and...

  8. 34 CFR 84.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Suspension. 84.670 Section 84.670 Education Office of... ASSISTANCE) Definitions § 84.670 Suspension. Suspension means an action taken by a Federal agency that...-wide Debarment and Suspension (Nonprocurement), that implements Executive Order 12549 and...

  9. 14 CFR 221.81 - Suspension supplement.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Suspension supplement. 221.81 Section 221...) ECONOMIC REGULATIONS TARIFFS Suspension of Tariff Provisions by Department § 221.81 Suspension supplement. (a) Suspension supplement. Upon receipt of an order of the Department suspending any tariff...

  10. Hydrodynamic shocks in microroller suspensions

    NASA Astrophysics Data System (ADS)

    Delmotte, Blaise; Driscoll, Michelle; Chaikin, Paul; Donev, Aleksandar

    2017-09-01

    We combine experiments, large-scale simulations, and continuum models to study the emergence of coherent structures in a suspension of magnetically driven microrollers sedimented near a floor. Collective hydrodynamic effects are predominant in this system, leading to strong density-velocity coupling. We characterize a uniform suspension and show that density waves propagate freely in all directions in a dispersive fashion. When sharp density gradients are introduced in the suspension, we observe the formation of a shock. Unlike Burgers' shocklike structures observed in other active and driven confined hydrodynamic systems, the shock front in our system has a well-defined finite width and moves rapidly compared to the mean suspension velocity. We introduce a continuum model demonstrating that the finite width of the front is due to far-field nonlocal hydrodynamic interactions and governed by a geometric parameter, the average particle height above the floor.

  11. Suspension of Registrations under FIFRA

    EPA Pesticide Factsheets

    Under FIFRA Section 3(c)(2)(B), this generally halts further distribution and sale of the suspended pesticide product by the registrant. Find suspension listings by product name, active ingredient, registrant name, date, and contact information.

  12. APPLICATION I: Levitation and Suspension

    NASA Astrophysics Data System (ADS)

    Murakami, Masato

    The following sections are included: * Introduction * Flux jump * Levitation * Physics experiment * Lunar telescope * Display * Suspension * Transport system on a guide rail * Transport system without magnetic guide rail * Summary * References

  13. Interagency Suspension and Debarment Committee

    EPA Pesticide Factsheets

    The Interagency Suspension and Debarment Committee (ISDC) was created, as an Office of Management and Budget (OMB) committee, by Executive Order 12549 for the purpose of monitoring the implementation of the Order.

  14. Automotive suspension system

    SciTech Connect

    Kanai, S.

    1986-11-11

    This patent describes an automotive suspension system comprising a wheel support for supporting a wheel, and a wheel supporting member for connecting the wheel support to the vehicle body. The wheel supporting member includes front and rear resilient supporting means spaced from each other by a predetermined distance in the longitudinal direction of the vehicle body and the direction of the toe of the wheel is adapted to be changed according to deformation of the front and rear resilient supporting means. The load-deformation characteristics of the front and rear resilient supporting means are selected so that the ratio of the amount of deformation of the front resilient supporting means for a given load to that of the rear resilient supporting means for the same load changes according to the magnitude of external side forces acting on the wheel, thereby changing the steering characteristics according to the magnitude of external force. The deformation is that in right and left or width directions of the vehicle body caused by the side forces.

  15. Debarment and suspension. [of contractors

    NASA Technical Reports Server (NTRS)

    Whelan, Thomas J.

    1987-01-01

    The changing Government attitude toward contractor debarment and suspension is examined, with emphasis on the fact that the Government is more alert to fraud, waste, and abuse. Consideration is given to causes of debarment or suspension, procedures and due process hearings, settlement agreements, compliance programs, and recent related legislation. It is concluded that the change in the Government contracting environment in recent years should be sufficient incentive for contractors to monitor their operations more closely.

  16. Extensional rheology of active suspensions.

    PubMed

    Saintillan, David

    2010-05-01

    A simple model is presented for the effective extensional rheology of a dilute suspension of active particles, such as self-propelled microswimmers, extending previous classical studies on suspensions of passive rodlike particles. Neglecting particle-particle hydrodynamic interactions, we characterize the configuration of the suspension by an orientation distribution, which satisfies a Fokker-Planck equation including the effects of an external flow field and of rotary diffusion. Knowledge of this orientation distribution then allows the determination of the particle extra stress as a configurational average of the force dipoles exerted by the particles on the fluid, which involve contributions from the imposed flow, rotary diffusion, and the permanent dipoles resulting from activity. Analytical expressions are obtained for the stress tensor in uniaxial extensional and compressional flows, as well as in planar extensional flow. In all types of flows, the effective viscosity is found to increase as a result of activity in suspensions of head-actuated swimmers (pullers) and to decrease in suspensions of tail-actuated swimmers (pushers). In the latter case, a negative particle viscosity is found to occur in weak flows. In planar extensional flow, we also characterize normal stresses, which are enhanced by activity in suspensions of pullers but reduced in suspensions of pushers. Finally, an energetic interpretation of the seemingly unphysical decrease in viscosity predicted in suspensions of pushers is proposed, where the decrease is explained as a consequence of the active power input generated by the swimming particles and is shown not to be directly related to viscous dissipative processes.

  17. Extensional rheology of active suspensions

    NASA Astrophysics Data System (ADS)

    Saintillan, David

    2010-05-01

    A simple model is presented for the effective extensional rheology of a dilute suspension of active particles, such as self-propelled microswimmers, extending previous classical studies on suspensions of passive rodlike particles. Neglecting particle-particle hydrodynamic interactions, we characterize the configuration of the suspension by an orientation distribution, which satisfies a Fokker-Planck equation including the effects of an external flow field and of rotary diffusion. Knowledge of this orientation distribution then allows the determination of the particle extra stress as a configurational average of the force dipoles exerted by the particles on the fluid, which involve contributions from the imposed flow, rotary diffusion, and the permanent dipoles resulting from activity. Analytical expressions are obtained for the stress tensor in uniaxial extensional and compressional flows, as well as in planar extensional flow. In all types of flows, the effective viscosity is found to increase as a result of activity in suspensions of head-actuated swimmers (pullers) and to decrease in suspensions of tail-actuated swimmers (pushers). In the latter case, a negative particle viscosity is found to occur in weak flows. In planar extensional flow, we also characterize normal stresses, which are enhanced by activity in suspensions of pullers but reduced in suspensions of pushers. Finally, an energetic interpretation of the seemingly unphysical decrease in viscosity predicted in suspensions of pushers is proposed, where the decrease is explained as a consequence of the active power input generated by the swimming particles and is shown not to be directly related to viscous dissipative processes.

  18. Debarment and suspension. [of contractors

    NASA Technical Reports Server (NTRS)

    Whelan, Thomas J.

    1987-01-01

    The changing Government attitude toward contractor debarment and suspension is examined, with emphasis on the fact that the Government is more alert to fraud, waste, and abuse. Consideration is given to causes of debarment or suspension, procedures and due process hearings, settlement agreements, compliance programs, and recent related legislation. It is concluded that the change in the Government contracting environment in recent years should be sufficient incentive for contractors to monitor their operations more closely.

  19. The suspension balance model revisited

    NASA Astrophysics Data System (ADS)

    Nott, Prabhu R.; Guazzelli, Elisabeth; Pouliquen, Olivier

    2011-04-01

    This paper addresses a fundamental discrepancy between the suspension balance model and other two-phase flow formulations. The former was proposed to capture the shear-induced migration of particles in Stokesian suspensions, and hinges on the presence of a particle phase stress to drive particle migration. This stress is taken to be the "particle stress," defined as the particle contribution to the suspension stress. On the other hand, the two-phase flow equations derived in several studies show only a force acting on the particle phase, but no stress. We show that the identification of the particle phase stress with the particle contribution to the suspension stress in the suspension balance model is incorrect, but there exists a well-defined particle phase stress. Following the rigorous method of volume averaging, we show that the force on the particle phase may be written as the sum of an interphase drag and the divergence of the particle phase stress. We derive exact micromechanical relations for these quantities. We also comment on the interpretations and results of previous studies that are based on the identification of the particle phase stress with the particle contribution to the suspension stress.

  20. Suspension biomechanics of swimming microbes

    PubMed Central

    Ishikawa, Takuji

    2009-01-01

    Micro-organisms play a vital role in many biological, medical and engineering phenomena. Some recent research efforts have demonstrated the importance of biomechanics in understanding certain aspects of micro-organism behaviours such as locomotion and collective motions of cells. In particular, spatio-temporal coherent structures found in a bacterial suspension have been the focus of many research studies over the last few years. Recent studies have shown that macroscopic properties of a suspension, such as rheology and diffusion, are strongly affected by meso-scale flow structures generated by swimming microbes. Since the meso-scale flow structures are strongly affected by the interactions between microbes, a bottom-up strategy, i.e. from a cellular level to a continuum suspension level, represents the natural approach to the study of a suspension of swimming microbes. In this paper, we first provide a summary of existing biomechanical research on interactions between a pair of swimming micro-organisms, as a two-body interaction is the simplest many-body interaction. We show that interactions between two nearby swimming micro-organisms are described well by existing mathematical models. Then, collective motions formed by a group of swimming micro-organisms are discussed. We show that some collective motions of micro-organisms, such as coherent structures of bacterial suspensions, are satisfactorily explained by fluid dynamics. Lastly, we discuss how macroscopic suspension properties are changed by the microscopic characteristics of the cell suspension. The fundamental knowledge we present will be useful in obtaining a better understanding of the behaviour of micro-organisms. PMID:19674997

  1. Improved All-Terrain Suspension System

    NASA Technical Reports Server (NTRS)

    Bickler, Donald B.

    1994-01-01

    Redesigned suspension system for all-terrain vehicle exhibits enhanced ability to negotiate sand and rocks. Improved six-wheel suspension system includes only two links on each side. Bogie tends to pull rear wheels with it as it climbs. Designed for rover vehicle for exploration of Mars, also has potential application in off-road vehicles, military scout vehicles, robotic emergency vehicles, and toys. Predecessors of suspension system described in "Articulated Suspension Without Springs" (NPO-17354), "Four-Wheel Vehicle Suspension System" (NPO-17407), and "High-Clearance Six-Wheel Suspension" (NPO-17821).

  2. Gravitational Instability in Suspension Flows

    NASA Technical Reports Server (NTRS)

    Carpen, Ileana C.; Brady, John F.

    2002-01-01

    The gravity-driven flow of non-neutrally buoyant suspensions is shown to be unstable to spanwise perturbations when the shearing motion generates a density profile that increases with height. The instability is simply due to having heavier material over light. The wavelength of the perturbation is found to be on the order of the thickness of the suspension layer. The parameters important to the problem are the angle of inclination of the layer relative to gravity, the relative density difference between the particles and fluid, the ratio of the particle size to the suspension layer, and the bulk volume fraction of particles. An example showing the growth rate as a function of wave number is shown.

  3. Rheology of vibrated granular suspensions

    NASA Astrophysics Data System (ADS)

    Kiesgen de Richter, Sebastien; Hanotin, Caroline; Gaudel, Naima; Louvet, Nicolas; Marchal, Philippe; Jenny, Mathieu

    2017-06-01

    In this work we investigate in details the flow behaviour of dense vibrated gravitational suspensions. We study the rheology in the stationary state by using a stress imposed rheometer (spectroscopy mechanics) coupled with a vibration cell, we show that applying well-controlled mechanical vibrations allows the control of the suspension viscosity by suppressing the apparent yield stress which is largely the cause of flow jamming. We show that the rheology in the stationary state is controlled by the competition between the reorganization time induced by the flow and the internal reorganization time induced by vibrations. We discuss the influence of particles size, suspending fluid viscosity and vibration parameters and demonstrate that the grains dynamics is controlled by the ratio between the lubrication stress and the granular pressure. This work evidences the major role played by the vibration induced lubrication stress on the liquefaction of vibrated granular suspensions.

  4. Earthquake Response of Suspension Bridges

    NASA Astrophysics Data System (ADS)

    Erdik, Mustafa; Apaydın, Nurdan

    Suspension bridges represent critical nodes of major transportation systems. Bridge failure during strong earthquakes poses not only a threat of fatalities but causes a substantial interruption of emergency efforts. Although wind induced vibrations have historically been the primary concern in the design of suspension bridges, earthquake effects have also gained importance in recent decades. This study involves ambient vibration testing and sophisticated three-dimensional dynamic finite element analysis and earthquake performance assessment of Fatih Sultan Mehmet and suspension Boğaziçi bridges in Istanbul under earthquake excitation. Nonlinear time history analysis of 3D finite-element models of Fatih Sultan Mehmet and Boğaziçi suspension bridges included initial stresses in the cables, suspenders, and towers in equilibrium under dead load conditions. Multi-support scenario earthquake excitation was applied to the structure. Suspension bridges are complex 3-D structures that can exhibit a large number of closely spaced coupled modes of vibration. The large number of closely spaced modes, spatially different ground motion characteristics, and the potential for nonlinear behaviour complicate the seismic response of suspension bridges. Spatial variation of ground motion exhibits itself with different ground motions at supports due to the wave passage, incoherence and local site effects. The source of nonlinear behaviour is due to geometric nonlinearity and the presence of cables that can only carry tensile forces. The natural frequencies of vibration and the corresponding mode shapes in their dead load and live load configurations are determined. Displacement time histories and stresses at critical points of the bridges are computed and their earthquake performance under the action of scenario earthquake are estimated.

  5. The Rheology of Concentrated Suspensions

    SciTech Connect

    Andreas Acrivos

    2004-09-07

    Research program on the rheological properties of flowing suspensions. The primary purpose of the research supported by this grant was to study the flow characteristics of concentrated suspensions of non-colloidal solid particles and thereby construct a comprehensive and robust theoretical framework for modeling such systems quantitatively. At first glance, this seemed like a modest goal, not difficult to achieve, given that such suspensions were viewed simply as Newtonian fluids with an effective viscosity equal to the product of the viscosity of the suspending fluid times a function of the particle volume fraction. But thanks to the research findings of the Principal Investigator and of his Associates, made possible by the steady and continuous support which the PI received from the DOE Office of Basic Energy Sciences, the subject is now seen to be more complicated and therefore much more interesting in that concentrated suspensions have been shown to exhibit fascinating and unique rheological properties of their own that have no counterpart in flowing Newtonian or even non-Newtonian (polymeric) fluids. In fact, it is generally acknowledged that, as the result of these investigations for which the PI received the 2001 National Medal of Science, our understanding of how suspensions behave under flow is far more detailed and comprehensive than was the case even as recently as a decade ago. Thus, given that the flow of suspensions plays a crucial role in many diverse physical processes, our work has had a major and lasting impact in a subject having both fundamental as well as practical importance.

  6. Airfoil flutter model suspension system

    NASA Technical Reports Server (NTRS)

    Reed, Wilmer H. (Inventor)

    1987-01-01

    A wind tunnel suspension system for testing flutter models under various loads and at various angles of attack is described. The invention comprises a mounting bracket assembly affixing the suspension system to the wind tunnel, a drag-link assembly and a compound spring arrangement comprises a plunge spring working in opposition to a compressive spring so as to provide a high stiffness to trim out steady state loads and simultaneously a low stiffness to dynamic loads. By this arrangement an airfoil may be tested for oscillatory response in both plunge and pitch modes while being held under high lifting loads in a wind tunnel.

  7. Precision magnetic suspension linear bearing

    NASA Technical Reports Server (NTRS)

    Trumper, David L.; Queen, Michael A.

    1992-01-01

    We have shown the design and analyzed the electromechanics of a linear motor suitable for independently controlling two suspension degrees of freedom. This motor, at least on paper, meets the requirements for driving an X-Y stage of 10 Kg mass with about 4 m/sq sec acceleration, with travel of several hundred millimeters in X and Y, and with reasonable power dissipation. A conceptual design for such a stage is presented. The theoretical feasibility of linear and planar bearings using single or multiple magnetic suspension linear motors is demonstrated.

  8. Characterizing Fullerene Nanoparticles in Aqueous Suspensions

    EPA Science Inventory

    Studies have indicated that fullerenes can form stable colloidal suspensions in water when introduced to the aqueous phase through solvent exchange, sonication, or extended mixing. The colloidal suspensions created using these techniques have effective aqueous phase concentratio...

  9. 39 CFR 957.27 - Suspension.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... through the Vice President who ordered the suspension within 20 days of the date upon which the respondent..., section 7 of the Postal Service Purchasing Manual who believes that the suspension has not been in...

  10. Characterizing Fullerene Nanoparticles in Aqueous Suspensions

    EPA Science Inventory

    Studies have indicated that fullerenes can form stable colloidal suspensions in water when introduced to the aqueous phase through solvent exchange, sonication, or extended mixing. The colloidal suspensions created using these techniques have effective aqueous phase concentratio...

  11. Four-Wheel Vehicle Suspension System

    NASA Technical Reports Server (NTRS)

    Bickler, Donald B.

    1990-01-01

    Four-wheel suspension system uses simple system of levers with no compliant components to provide three-point suspension of chassis of vehicle while maintaining four-point contact with uneven terrain. Provides stability against tipping of four-point rectangular base, without rocking contact to which rigid four-wheel frame susceptible. Similar to six-wheel suspension system described in "Articulated Suspension Without Springs" (NPO-17354).

  12. Suspense at the Ballot Box

    ERIC Educational Resources Information Center

    Kell, Nat; Kretchmar, Matt

    2013-01-01

    In the popular television show "Survivor", the winner of a million-dollar prize is determined in a final election, where the votes are read aloud as the winner is announced. We hypothesize that the show's producers purposely alter the order of the ballots in order to build audience suspense. We test our hypothesis using the Poisson binomial…

  13. Hindlimb suspension reduces muscle regeneration

    NASA Technical Reports Server (NTRS)

    Mozdziak, P. E.; Truong, Q.; Macius, A.; Schultz, E.

    1998-01-01

    Exposure of juvenile skeletal muscle to a weightless environment reduces growth and satellite cell mitotic activity. However, the effect of a weightless environment on the satellite cell population during muscle repair remains unknown. Muscle injury was induced in rat soleus muscles using the myotoxic snake venom, notexin. Rats were placed into hindlimb-suspended or weightbearing groups for 10 days following injury. Cellular proliferation during regeneration was evaluated using 5-bromo-2'-deoxyuridine (BrdU) immunohistochemistry and image analysis. Hindlimb suspension reduced (P < 0.05) regenerated muscle mass, regenerated myofiber diameter, uninjured muscle mass, and uninjured myofiber diameter compared to weightbearing rats. Hindlimb suspension reduced (P < 0.05) BrdU labeling in uninjured soleus muscles compared to weight-bearing muscles. However, hindlimb suspension did not abolish muscle regeneration because myofibers formed in the injured soleus muscles of hindlimb-suspended rats, and BrdU labeling was equivalent (P > 0.10) on myofiber segments isolated from the soleus muscles of hindlimb-suspended and weightbearing rats following injury. Thus, hindlimb suspension (weightlessness) does not suppress satellite cell mitotic activity in regenerating muscles before myofiber formation, but reduces growth of the newly formed myofibers.

  14. Suspense at the Ballot Box

    ERIC Educational Resources Information Center

    Kell, Nat; Kretchmar, Matt

    2013-01-01

    In the popular television show "Survivor", the winner of a million-dollar prize is determined in a final election, where the votes are read aloud as the winner is announced. We hypothesize that the show's producers purposely alter the order of the ballots in order to build audience suspense. We test our hypothesis using the Poisson binomial…

  15. Microgravity combustion of dust suspensions

    NASA Technical Reports Server (NTRS)

    Lee, John H. S.; Peraldi, Olivier; Knystautas, Rom

    1993-01-01

    Unlike the combustion of homogeneous gas mixtures, there are practically no reliable fundamental data (i.e., laminar burning velocity, flammability limits, quenching distance, minimum ignition energy) for the combustion of heterogeneous dust suspensions. Even the equilibrium thermodynamic data such as the constant pressure volume combustion pressure and the constant pressure adiabatic flame temperature are not accurately known for dust mixtures. This is mainly due to the problem of gravity sedimentation. In normal gravity, turbulence, convective flow, electric and acoustic fields are required to maintain a dust in suspension. These external influences have a dominating effect on the combustion processes. Microgravity offers a unique environment where a quiescent dust cloud can in principle be maintained for a sufficiently long duration for almost all combustion experiments (dust suspensions are inherently unstable due to Brownian motion and particle aggregation). Thus, the microgravity duration provided by drop towers, parabolic flights, and the space shuttle, can all be exploited for different kinds of dust combustion experiments. The present paper describes some recent studies on microgravity combustion of dust suspension carried out on the KC-135 and the Caravelle aircraft. The results reported are obtained from three parabolic flight campaigns.

  16. Casimir effect in swimmer suspensions.

    PubMed

    Parra-Rojas, C; Soto, R

    2014-07-01

    We show that the Casimir effect can emerge in microswimmer suspensions. In principle, two effects conspire against the development of Casimir effects in swimmer suspensions. First, at low Reynolds number, the force on any closed volume vanishes, but here the relevant effect is the drag by the flow produced by the swimmers, which can be finite. Second, the fluid velocity and the pressure are linear on the swimmer force dipoles, and averaging over the swimmer orientations would lead to a vanishing effect. However, being that the suspension is a discrete system, the noise terms of the coarse-grained equations depend on the density, which itself fluctuates, resulting in effective nonlinear dynamics. Applying the tools developed for other nonequilibrium systems to general coarse-grained equations for swimmer suspensions, the Casimir drag is computed on immersed objects, and it is found to depend on the correlation function between the rescaled density and dipolar density fields. By introducing a model correlation function with medium-range order, explicit expressions are obtained for the Casimir drag on a body. When the correlation length is much larger than the microscopic cutoff, the average drag is independent of the correlation length, with a range that depends only on the size of the immersed bodies.

  17. Casimir effect in swimmer suspensions

    NASA Astrophysics Data System (ADS)

    Parra-Rojas, C.; Soto, R.

    2014-07-01

    We show that the Casimir effect can emerge in microswimmer suspensions. In principle, two effects conspire against the development of Casimir effects in swimmer suspensions. First, at low Reynolds number, the force on any closed volume vanishes, but here the relevant effect is the drag by the flow produced by the swimmers, which can be finite. Second, the fluid velocity and the pressure are linear on the swimmer force dipoles, and averaging over the swimmer orientations would lead to a vanishing effect. However, being that the suspension is a discrete system, the noise terms of the coarse-grained equations depend on the density, which itself fluctuates, resulting in effective nonlinear dynamics. Applying the tools developed for other nonequilibrium systems to general coarse-grained equations for swimmer suspensions, the Casimir drag is computed on immersed objects, and it is found to depend on the correlation function between the rescaled density and dipolar density fields. By introducing a model correlation function with medium-range order, explicit expressions are obtained for the Casimir drag on a body. When the correlation length is much larger than the microscopic cutoff, the average drag is independent of the correlation length, with a range that depends only on the size of the immersed bodies.

  18. Shear Thinning of Noncolloidal Suspensions

    NASA Astrophysics Data System (ADS)

    Vázquez-Quesada, Adolfo; Tanner, Roger I.; Ellero, Marco

    2016-09-01

    Shear thinning—a reduction in suspension viscosity with increasing shear rates—is understood to arise in colloidal systems from a decrease in the relative contribution of entropic forces. The shear-thinning phenomenon has also been often reported in experiments with noncolloidal systems at high volume fractions. However its origin is an open theoretical question and the behavior is difficult to reproduce in numerical simulations where shear thickening is typically observed instead. In this letter we propose a non-Newtonian model of interparticle lubrication forces to explain shear thinning in noncolloidal suspensions. We show that hidden shear-thinning effects of the suspending medium, which occur at shear rates orders of magnitude larger than the range investigated experimentally, lead to significant shear thinning of the overall suspension at much smaller shear rates. At high particle volume fractions the local shear rates experienced by the fluid situated in the narrow gaps between particles are much larger than the averaged shear rate of the whole suspension. This allows the suspending medium to probe its high-shear non-Newtonian regime and it means that the matrix fluid rheology must be considered over a wide range of shear rates.

  19. Shear Thinning of Noncolloidal Suspensions.

    PubMed

    Vázquez-Quesada, Adolfo; Tanner, Roger I; Ellero, Marco

    2016-09-02

    Shear thinning-a reduction in suspension viscosity with increasing shear rates-is understood to arise in colloidal systems from a decrease in the relative contribution of entropic forces. The shear-thinning phenomenon has also been often reported in experiments with noncolloidal systems at high volume fractions. However its origin is an open theoretical question and the behavior is difficult to reproduce in numerical simulations where shear thickening is typically observed instead. In this letter we propose a non-Newtonian model of interparticle lubrication forces to explain shear thinning in noncolloidal suspensions. We show that hidden shear-thinning effects of the suspending medium, which occur at shear rates orders of magnitude larger than the range investigated experimentally, lead to significant shear thinning of the overall suspension at much smaller shear rates. At high particle volume fractions the local shear rates experienced by the fluid situated in the narrow gaps between particles are much larger than the averaged shear rate of the whole suspension. This allows the suspending medium to probe its high-shear non-Newtonian regime and it means that the matrix fluid rheology must be considered over a wide range of shear rates.

  20. Large gap magnetic suspension system

    NASA Technical Reports Server (NTRS)

    Abdelsalam, Moustafa K.; Eyssa, Y. M.

    1991-01-01

    The design of a large gap magnetic suspension system is discussed. Some of the topics covered include: the system configuration, permanent magnet material, levitation magnet system, superconducting magnets, resistive magnets, superconducting levitation coils, resistive levitation coils, levitation magnet system, and the nitrogen cooled magnet system.

  1. Power dissipation in automotive suspensions

    NASA Astrophysics Data System (ADS)

    Smith, Malcolm C.; Swift, Stuart J.

    2011-02-01

    For a standard quarter-car vehicle model and a road disturbance whose velocity profile is white noise, it is shown that the power dissipated in the suspension is proportional to the tyre vertical stiffness and the noise intensity, but is independent of all masses and suspension parameters. The dependence of this result on the modelling assumptions is explored. It is shown that the road disturbance model is ill-posed for the computation of power dissipation in the tyre and a modification is suggested. Computational results then indicate that the total power dissipation is still very insensitive to variations in vehicle and suspension parameters, but not tyre parameters, even though the suspension power dissipation and the tyre power dissipation vary individually. The extension of the result to half-car vehicle models is also considered. For both the pitch-plane and roll-plane models, it is found from numerical examples that the broad conclusion of large dependence of the total power dissipation on tyre parameters and small dependence on all other parameters remains. A brief discussion is included on the contribution to power loss due to rolling resistance.

  2. Hindlimb suspension reduces muscle regeneration

    NASA Technical Reports Server (NTRS)

    Mozdziak, P. E.; Truong, Q.; Macius, A.; Schultz, E.

    1998-01-01

    Exposure of juvenile skeletal muscle to a weightless environment reduces growth and satellite cell mitotic activity. However, the effect of a weightless environment on the satellite cell population during muscle repair remains unknown. Muscle injury was induced in rat soleus muscles using the myotoxic snake venom, notexin. Rats were placed into hindlimb-suspended or weightbearing groups for 10 days following injury. Cellular proliferation during regeneration was evaluated using 5-bromo-2'-deoxyuridine (BrdU) immunohistochemistry and image analysis. Hindlimb suspension reduced (P < 0.05) regenerated muscle mass, regenerated myofiber diameter, uninjured muscle mass, and uninjured myofiber diameter compared to weightbearing rats. Hindlimb suspension reduced (P < 0.05) BrdU labeling in uninjured soleus muscles compared to weight-bearing muscles. However, hindlimb suspension did not abolish muscle regeneration because myofibers formed in the injured soleus muscles of hindlimb-suspended rats, and BrdU labeling was equivalent (P > 0.10) on myofiber segments isolated from the soleus muscles of hindlimb-suspended and weightbearing rats following injury. Thus, hindlimb suspension (weightlessness) does not suppress satellite cell mitotic activity in regenerating muscles before myofiber formation, but reduces growth of the newly formed myofibers.

  3. Engineering of Novel Biocolloid Suspensions

    NASA Technical Reports Server (NTRS)

    Hammer, D. A.; Rodges, S.; Hiddessen, A.; Weitz, D. A.

    1999-01-01

    Colloidal suspensions are materials with a variety of uses from cleaners and lubricants to food, cosmetics, and coatings. In addition, they can be used as a tool for testing the fundamental tenets of statistical physics. Colloidal suspensions can be synthesized from a wide variety of materials, and in the form of monodisperse particles, which can self-assemble into highly ordered colloidal crystal structures. As such they can also be used as templates for the construction of highly ordered materials. Materials design of colloids has, to date, relied on entropic self-assembly, where crystals form as result of lower free energy due to a transition to order. Here, our goal is to develop a completely new method for materials fabrication using colloidal precursors, in which the self-assembly of the ordered colloidal structures is driven by a highly controllable, attractive interaction. This will greatly increase the range of potential structures that can be fabricated with colloidal particles. In this work, we demonstrate that colloidal suspensions can be crosslinked through highly specific biological crosslinking reactions. In particular, the molecules we use are protein-carbohydrate interactions derived from the immune system. This different driving force for self-assembly will yield different and novel suspensions structures. Because the biological interactions are heterotypic (A binding to B), this chemical system can be used to make binary alloys in which the two colloid subpopulations vary in some property - size, density, volume fraction, magnetic susceptibility, etc. An additional feature of these molecules which is unique - even within the realm of biological recognition - is that the molecules bind reversibly on reasonable time-scales, which will enable the suspension to sample different configurations, and allow us to manipulate and measure the size of the suspension dynamically. Because of the wide variety of structures that can be made from these novel

  4. 49 CFR 570.8 - Suspension systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 6 2011-10-01 2011-10-01 false Suspension systems. 570.8 Section 570.8 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY... Pounds or Less § 570.8 Suspension systems. (a) Suspension condition. Ball joint seals shall not be cut or...

  5. 49 CFR 570.61 - Suspension system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 6 2011-10-01 2011-10-01 false Suspension system. 570.61 Section 570.61 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY... 10,000 Pounds § 570.61 Suspension system. (a) Suspension condition. Ball joint seals shall not be cut...

  6. 49 CFR 393.207 - Suspension systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Suspension systems. 393.207 Section 393.207... NECESSARY FOR SAFE OPERATION Frames, Cab and Body Components, Wheels, Steering, and Suspension Systems § 393.207 Suspension systems. (a) Axles. No axle positioning part shall be cracked, broken, loose or missing...

  7. 31 CFR 20.670 - Suspension.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 31 Money and Finance: Treasury 1 2013-07-01 2013-07-01 false Suspension. 20.670 Section 20.670 Money and Finance: Treasury Office of the Secretary of the Treasury GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 20.670 Suspension. Suspension means an action...

  8. 31 CFR 20.670 - Suspension.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 31 Money and Finance: Treasury 1 2012-07-01 2012-07-01 false Suspension. 20.670 Section 20.670 Money and Finance: Treasury Office of the Secretary of the Treasury GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 20.670 Suspension. Suspension means an action...

  9. 31 CFR 20.670 - Suspension.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance: Treasury 1 2011-07-01 2011-07-01 false Suspension. 20.670 Section 20.670 Money and Finance: Treasury Office of the Secretary of the Treasury GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 20.670 Suspension. Suspension means an action...

  10. 31 CFR 20.670 - Suspension.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 31 Money and Finance: Treasury 1 2014-07-01 2014-07-01 false Suspension. 20.670 Section 20.670 Money and Finance: Treasury Office of the Secretary of the Treasury GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 20.670 Suspension. Suspension means an action...

  11. 22 CFR 210.670 - Suspension.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Suspension. 210.670 Section 210.670 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 210.670 Suspension. Suspension means an action taken by a Federal...

  12. 22 CFR 1509.670 - Suspension.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 2 2014-04-01 2014-04-01 false Suspension. 1509.670 Section 1509.670 Foreign Relations AFRICAN DEVELOPMENT FOUNDATION GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 1509.670 Suspension. Suspension means an action taken by a Federal agency...

  13. 22 CFR 1509.670 - Suspension.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 2 2013-04-01 2009-04-01 true Suspension. 1509.670 Section 1509.670 Foreign Relations AFRICAN DEVELOPMENT FOUNDATION GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 1509.670 Suspension. Suspension means an action taken by a Federal agency...

  14. 22 CFR 1509.670 - Suspension.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 2 2012-04-01 2009-04-01 true Suspension. 1509.670 Section 1509.670 Foreign Relations AFRICAN DEVELOPMENT FOUNDATION GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 1509.670 Suspension. Suspension means an action taken by a Federal agency...

  15. 22 CFR 1509.670 - Suspension.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 2 2011-04-01 2009-04-01 true Suspension. 1509.670 Section 1509.670 Foreign Relations AFRICAN DEVELOPMENT FOUNDATION GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 1509.670 Suspension. Suspension means an action taken by a Federal agency...

  16. 24 CFR 21.670 - Suspension.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 1 2011-04-01 2011-04-01 false Suspension. 21.670 Section 21.670 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (GRANTS) Definitions § 21.670 Suspension. Suspension means...

  17. 49 CFR 570.61 - Suspension system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 6 2012-10-01 2012-10-01 false Suspension system. 570.61 Section 570.61 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY... 10,000 Pounds § 570.61 Suspension system. (a) Suspension condition. Ball joint seals shall not be cut...

  18. 49 CFR 570.8 - Suspension systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 6 2014-10-01 2014-10-01 false Suspension systems. 570.8 Section 570.8 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY... Pounds or Less § 570.8 Suspension systems. (a) Suspension condition. Ball joint seals shall not be cut or...

  19. 49 CFR 570.8 - Suspension systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 6 2012-10-01 2012-10-01 false Suspension systems. 570.8 Section 570.8 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY... Pounds or Less § 570.8 Suspension systems. (a) Suspension condition. Ball joint seals shall not be cut or...

  20. 49 CFR 570.61 - Suspension system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 6 2014-10-01 2014-10-01 false Suspension system. 570.61 Section 570.61 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY... 10,000 Pounds § 570.61 Suspension system. (a) Suspension condition. Ball joint seals shall not be cut...

  1. Flow properties of suspensions rich in solids

    NASA Technical Reports Server (NTRS)

    Armstrong, W. P.; Gay, E. C.; Nelson, P. A.

    1969-01-01

    Mathematical evaluation of flow properties of fluids carrying high concentrations of solids in suspension relates suspension viscosity to physical properties of the solids and liquids, and provides a means for predicting flow behavior. A technique for calculating a suspensions flow rates is applicable to the design of pipelines.

  2. Alternatives to Suspensions: Rationale and Recommendations

    ERIC Educational Resources Information Center

    Chin, Jenna K.; Dowdy, Erin; Jimerson, Shane R.; Rime, W. Jeremy

    2012-01-01

    Suspensions are often used as an individual disciplinary consequence in attempts to reduce problem behaviors in the future. However, suspensions have shown to be less effective for students with specific behavioral challenges and problems. When examining suspensions in the context of behaviorist and social-ecological learning theories, suspending…

  3. 13 CFR 147.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Suspension. 147.670 Section 147.670 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (NONPROCUREMENT) Definitions § 147.670 Suspension. Suspension means an action taken by a...

  4. 45 CFR 630.670 - Suspension.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 3 2011-10-01 2011-10-01 false Suspension. 630.670 Section 630.670 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 630.670 Suspension. Suspension means an action...

  5. 29 CFR 4281.41 - Benefit suspensions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 9 2010-07-01 2010-07-01 false Benefit suspensions. 4281.41 Section 4281.41 Labor Regulations Relating to Labor (Continued) PENSION BENEFIT GUARANTY CORPORATION INSOLVENCY, REORGANIZATION... WITHDRAWAL Benefit Suspensions § 4281.41 Benefit suspensions. If the plan sponsor determines that the plan...

  6. 48 CFR 309.407 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Suspension. 309.407 Section 309.407 Federal Acquisition Regulations System HEALTH AND HUMAN SERVICES COMPETITION AND ACQUISITION PLANNING CONTRACTOR QUALIFICATIONS Debarment, Suspension, and Ineligibility 309.407 Suspension....

  7. 7 CFR 3015.123 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Suspension. 3015.123 Section 3015.123 Agriculture... AGRICULTURE UNIFORM FEDERAL ASSISTANCE REGULATIONS Grant and Subgrant Closeout, Suspension and Termination § 3015.123 Suspension. (a) When a recipient has materially failed to comply with the...

  8. 48 CFR 1309.407 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Suspension. 1309.407 Section 1309.407 Federal Acquisition Regulations System DEPARTMENT OF COMMERCE COMPETITION AND ACQUISITION PLANNING CONTRACTOR QUALIFICATIONS Debarment, Suspension, and Ineligibility 1309.407 Suspension....

  9. 48 CFR 1509.407 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Suspension. 1509.407 Section 1509.407 Federal Acquisition Regulations System ENVIRONMENTAL PROTECTION AGENCY ACQUISITION PLANNING CONTRACTOR QUALIFICATIONS Debarment, Suspension and Ineligibility 1509.407 Suspension....

  10. 22 CFR 34.20 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Suspension. 34.20 Section 34.20 Foreign Relations DEPARTMENT OF STATE CLAIMS AND STOLEN PROPERTY DEBT COLLECTION Collection Adjustments § 34.20 Suspension. The suspension of collection action shall be made in accordance with the standards set forth...

  11. 48 CFR 1409.407 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Suspension. 1409.407 Section 1409.407 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR COMPETITION AND ACQUISITION PLANNING CONTRACTOR QUALIFICATIONS Debarment, Suspension, and Ineligibility 1409.407 Suspension....

  12. 48 CFR 909.407 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Suspension. 909.407 Section 909.407 Federal Acquisition Regulations System DEPARTMENT OF ENERGY COMPETITION ACQUISITION PLANNING CONTRACTOR QUALIFICATIONS Debarment, Suspension, and Ineligibility 909.407 Suspension....

  13. 22 CFR 127.8 - Interim suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Interim suspension. 127.8 Section 127.8 Foreign... Interim suspension. (a) The Managing Director of the Directorate of Defense Trade Controls or the Director of the Office of Defense Trade Controls Compliance is authorized to order the interim suspension...

  14. 48 CFR 9.407 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Suspension. 9.407 Section 9.407 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION ACQUISITION PLANNING CONTRACTOR QUALIFICATIONS Debarment, Suspension, and Ineligibility 9.407 Suspension....

  15. 75 FR 24494 - Nonprocurement Debarment and Suspension

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-05

    ...; ] ELECTION ASSISTANCE COMMISSION 2 CFR Chapter 58 Nonprocurement Debarment and Suspension AGENCY: U.S... proposed debarment and suspension regulations. These proposed regulations will apply to nonprocurement... Management and Budget (OMB) in a document on nonprocurement debarment and suspension published in the...

  16. 40 CFR 36.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Suspension. 36.670 Section 36.670... REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 36.670 Suspension. Suspension means... contracts (48 CFR part 9, subpart 9.4) and the common rule, Government-wide Debarment and...

  17. 21 CFR 520.1806 - Piperazine suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Piperazine suspension. 520.1806 Section 520.1806... DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.1806 Piperazine suspension. (a) Specifications. Each milliliter of suspension contains piperazine monohydrochloride equivalent...

  18. 36 CFR 1212.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Suspension. 1212.670 Section... GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 1212.670 Suspension. Suspension means an action taken by a Federal agency that immediately prohibits a recipient...

  19. 48 CFR 609.407 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Suspension. 609.407 Section 609.407 Federal Acquisition Regulations System DEPARTMENT OF STATE COMPETITION AND ACQUISITION PLANNING CONTRACTOR QUALIFICATIONS Debarment, Suspension, and Ineligibility 609.407 Suspension....

  20. 25 CFR 23.52 - Grant suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Grant suspension. 23.52 Section 23.52 Indians BUREAU OF... Grant Administration Provisions and Requirements § 23.52 Grant suspension. (a) When a grantee has... assistance, suspend the grant. The notice preceding the suspension shall include the effective date of...

  1. 36 CFR 223.141 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Suspension. 223.141 Section... DISPOSAL OF NATIONAL FOREST SYSTEM TIMBER Suspension and Debarment of Timber Purchasers § 223.141 Suspension. (a) The suspending official may, in the public interest, suspend a purchaser on the basis...

  2. 32 CFR 26.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 1 2010-07-01 2010-07-01 false Suspension. 26.670 Section 26.670 National... GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 26.670 Suspension. Suspension means an action taken by a Federal agency that immediately prohibits a recipient...

  3. 12 CFR 367.7 - Suspensions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Suspensions. 367.7 Section 367.7 Banks and Banking FEDERAL DEPOSIT INSURANCE CORPORATION REGULATIONS AND STATEMENTS OF GENERAL POLICY SUSPENSION AND EXCLUSION OF CONTRACTOR AND TERMINATION OF CONTRACTS § 367.7 Suspensions. (a) The Ethics Counselor...

  4. 45 CFR 1623.4 - Suspension procedures.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Suspension procedures. 1623.4 Section 1623.4 Public Welfare Regulations Relating to Public Welfare (Continued) LEGAL SERVICES CORPORATION SUSPENSION PROCEDURES § 1623.4 Suspension procedures. (a) When the Corporation has made a proposed determination,...

  5. 48 CFR 2009.407 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Suspension. 2009.407 Section 2009.407 Federal Acquisition Regulations System NUCLEAR REGULATORY COMMISSION COMPETITION AND ACQUISITION PLANNING CONTRACTOR QUALIFICATIONS Debarment, Suspension, and Ineligibility 2009.407 Suspension....

  6. 48 CFR 409.407 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Suspension. 409.407 Section 409.407 Federal Acquisition Regulations System DEPARTMENT OF AGRICULTURE COMPETITION AND ACQUISITION PLANNING CONTRACTOR QUALIFICATIONS Debarment, Suspension and Ineligibility 409.407 Suspension....

  7. 48 CFR 2509.407 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Suspension. 2509.407 Section 2509.407 Federal Acquisition Regulations System NATIONAL SCIENCE FOUNDATION ACQUISITION PLANNING CONTRACTOR QUALIFICATIONS Debarment, Suspension, and Ineligibility 2509.407 Suspension....

  8. 45 CFR 1210.3-3 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Suspension. 1210.3-3 Section 1210.3-3 Public... § 1210.3-3 Suspension. (a) The ACTION State Director may suspend a Volunteer for up to 30 days in order... Volunteer. Suspension is not warranted if the State Director determines that sufficient grounds...

  9. 48 CFR 809.407 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Suspension. 809.407 Section 809.407 Federal Acquisition Regulations System DEPARTMENT OF VETERANS AFFAIRS COMPETITION AND ACQUISITION PLANNING CONTRACTOR QUALIFICATIONS Debarment, Suspension, and Ineligibility 809.407 Suspension....

  10. 38 CFR 48.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Suspension. 48.670...) GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 48.670 Suspension. Suspension means an action taken by a Federal agency that immediately prohibits a recipient...

  11. 48 CFR 509.407 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Suspension. 509.407 Section 509.407 Federal Acquisition Regulations System GENERAL SERVICES ADMINISTRATION COMPETITION AND ACQUISITION PLANNING CONTRACTOR QUALIFICATIONS Debarment, Suspension, and Ineligibility 509.407 Suspension....

  12. 22 CFR 312.670 - Suspension.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 2 2012-04-01 2009-04-01 true Suspension. 312.670 Section 312.670 Foreign Relations PEACE CORPS GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 312.670 Suspension. Suspension means an action taken by a Federal agency that immediately prohibits...

  13. 22 CFR 312.670 - Suspension.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 2 2013-04-01 2009-04-01 true Suspension. 312.670 Section 312.670 Foreign Relations PEACE CORPS GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 312.670 Suspension. Suspension means an action taken by a Federal agency that immediately prohibits...

  14. 45 CFR 630.670 - Suspension.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 3 2012-10-01 2012-10-01 false Suspension. 630.670 Section 630.670 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 630.670 Suspension. Suspension means an action...

  15. 45 CFR 630.670 - Suspension.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 3 2014-10-01 2014-10-01 false Suspension. 630.670 Section 630.670 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 630.670 Suspension. Suspension means an action...

  16. 45 CFR 630.670 - Suspension.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 3 2013-10-01 2013-10-01 false Suspension. 630.670 Section 630.670 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 630.670 Suspension. Suspension means an action...

  17. 22 CFR 127.8 - Interim suspension.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Interim suspension. (a) The Managing Director of the Directorate of Defense Trade Controls or the Director of the Office of Defense Trade Controls Compliance is authorized to order the interim suspension of... world peace or the security or foreign policy of the United States. The interim suspension orders...

  18. Part A: Hydrocarbon Suspension in Slush Hydrogen

    NASA Technical Reports Server (NTRS)

    Sindt, C. F.

    1972-01-01

    Methods of preparing suspensions of a hydrocarbon in slush hydrogen for nuclear fuel element corrosion inhibition in rocket engines were investigated. Suspensions were prepared using approximately 5000 ppm by mass of methane, ethane, or cyclopropane in slush hydrogen. The suspensions were stable in the slush, but the hydrocarbons settled out of the liquid melt.

  19. 10 CFR 607.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Suspension. 607.670 Section 607.670 Energy DEPARTMENT OF ENERGY (CONTINUED) ASSISTANCE REGULATIONS GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 607.670 Suspension. Suspension means an action taken by a Federal agency...

  20. 45 CFR 1210.3-3 - Suspension.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... § 1210.3-3 Suspension. (a) The ACTION State Director may suspend a Volunteer for up to 30 days in order... to the Volunteer. Within 3 days after initiation of the suspension, the Volunteer will receive a... allowances, including stipend. (c) At the end of the suspension period, the Volunteer must either be...

  1. Characteristics of Students Who Reenroll after Serving a Disciplinary Suspension

    ERIC Educational Resources Information Center

    Stimpson, Matthew T.; Janosik, Steven M.

    2007-01-01

    The purpose of this study was to examine if students who reenroll following a disciplinary suspension had significant common characteristics. Gender, GPA at time of suspension, class status at time of suspension, type of violation(s) that resulted in suspension, number of disciplinary incidents prior to suspension, and length of suspension were…

  2. Chain Dynamics in Magnetorheological Suspensions

    NASA Technical Reports Server (NTRS)

    Gast, A. P.; Furst, E. M.

    1999-01-01

    Magnetorheological (MR) suspensions are composed of colloidal particles which acquire dipole moments when subjected to an external magnetic field. At sufficient field strengths and concentrations, the dipolar particles rapidly aggregate to form long chains. Subsequent lateral cross-linking of the dipolar chains is responsible for a rapid liquid-to-solid-like rheological transition. The unique, magnetically-activated rheological properties of MR suspensions make them ideal for interfacing mechanical systems to electronic controls. Additionally, the ability to experimentally probe colloidal suspensions interacting through tunable anisotropic potentials is of fundamental interest. Our current experimental work has focused on understanding the fluctuations of dipolar chains. It has been proposed by Halsey and Toor (HT) that the strong Landau-Peierls thermal fluctuations of dipolar chains could be responsible for long-range attractions between chains. Such interactions will govern the long-time relaxation of MR suspensions. We have synthesized monodisperse neutrally buoyant MR suspensions by density matching stabilized ferrofluid emulsion droplets with D2O. This allows us to probe the dynamics of the dipolar chains using light scattering without gravitational, interfacial, and polydispersity effects to resolve the short-wavelength dynamics of the dipolar chains. We used diffusing wave spectroscopy to measure these dynamics. The particle displacements at short times that show an independence to the field strength, but at long times exhibit a constrained, sub-diffusive motion that slows as the dipole strength is increased. The experiments are in good qualitative agreement with Brownian dynamics simulations of dipolar chains. Although there have been several important and detailed studies of the structure and interactions in MR suspensions, there has not been conclusive evidence that supports or contradicts the HT model prediction that long-range interactions exist between

  3. Parasite transmission through suspension feeding.

    PubMed

    Ben-Horin, Tal; Bidegain, Gorka; Huey, Lauren; Narvaez, Diego A; Bushek, David

    2015-10-01

    Suspension-feeding bivalve molluscs are confronted with a wide range of materials in the benthic marine environment. These materials include various sized plankton and the organic material derived from it, macroalgae, detritus and a diversity of microbial parasites that have adapted life stages to survive in the water column. For bivalve parasites to infect hosts though, they must first survive and remain infectious in the water column to make initial contact with hosts, and once in contact, enter and overcome elaborate pathways for particle sorting and selection. Even past these defenses, bivalve parasites are challenged with efficient systems of mechanical and chemical digestion and highly evolved systems of innate immunity. Here we review how bivalve parasites evade these hurdles to complete their life cycles and establish within bivalve hosts. We broadly cover significant viral, bacterial, and protozoan parasites of marine bivalve molluscs, and illustrate the emergent properties of these host-parasite systems where parasite transmission occurs through suspension feeding.

  4. Wood fuel in suspension burners

    SciTech Connect

    Wolle, P.C.

    1982-01-01

    Experience and criteria for solid fuel suspension burning is presented based on more than ten years of actual experience with commercially installed projects. Fuel types discussed range from dried wood with less than 15% moisture content, wet basis, to exotic biomass material such as brewed tea leaves and processed coffee grounds. Single burner inputs range from 1,465 kW (5,000 Mbh) to 13,771 kW (47,000 Mbh) as well as multiple burner applications with support burning using fuel oil and/or natural gas. General requirements for self-sustaining combustion will be reviewed as applied to suspension solid fuel burning, together with results of what can happen if these requirements are not met. Solid fuel preparation, sizing, transport, storage, and metering control is essential for proper feed. Combustion chamber volume, combustion air requirements, excess air, and products of combustion are reviewed, together with induced draft fan sizing. (Refs. 7).

  5. Strut type suspension for automobile

    SciTech Connect

    Sakata, M.; Minakawa, M.

    1986-11-04

    This patent describes a strut type suspension for automobiles having a chassis. The suspension comprises a support member for rotatably supporting a wheel, a lower control arm extending in the widthwise direction of the chassis and connected pivotably at its outer ends and extending substantially in a longitudinal direction of the chassis with the one end thereof pivotably connected to the chassis, and a brake unit in the wheel. The brake unit is in a central portion of the wheel with a recess opened to an inner side of the chassis, the support member having an integral member extending inwardly and downwardly of the chassis and connected with the other end of the radius rod. The outer end of the lower control arm is pivoted to the support member extending into the recess so that the pivot is located close to the center line contact of the wheel with the ground.

  6. Crackling of a coagulating suspension

    NASA Astrophysics Data System (ADS)

    Sarcia, Régis; Hébraud, Pascal

    2005-07-01

    A way of analyzing the intermittent dynamics of nonstationary systems is introduced. It is used to study the dynamics of a concentrated suspension while it is flocculating, probed by diffusing wave spectroscopy. When the repulsion interactions between the particles are slowly decreased their motion appears to be intermittent. It is characterized by rapid crackling periods, separated by arrested dynamics. Duration of the crackling periods exhibit a power-law distribution function.

  7. Robust Tensioned Kevlar Suspension Design

    NASA Technical Reports Server (NTRS)

    Young, Joseph B.; Naylor, Bret J.; Holmes, Warren A.

    2012-01-01

    One common but challenging problem in cryogenic engineering is to produce a mount that has excellent thermal isolation but is also rigid. Such mounts can be achieved by suspending the load from a network of fibers or strings held in tension. Kevlar fibers are often used for this purpose owing to their high strength and low thermal conductivity. A suite of compact design elements has been developed to improve the reliability of suspension systems made of Kevlar.

  8. Particle Suspension Mechanisms - Supplemental Material

    SciTech Connect

    Dillon, M B

    2011-03-03

    This supplemental material provides a brief introduction to particle suspension mechanisms that cause exfoliated skin cells to become and remain airborne. The material presented here provides additional context to the primary manuscript and serves as background for designing possible future studies to assess the impact of skin cells as a source of infectious aerosols. This introduction is not intended to be comprehensive and interested readers are encouraged to consult the references cited.

  9. Fouling dynamics in suspension flows

    NASA Astrophysics Data System (ADS)

    Shakib-Manesh, A.; Åström, J. A.; Koponen, A.; Raiskinmäki, P.; Timonen, J.

    2002-09-01

    A particle suspension flowing in a channel in which fouling layers are allowed to form on the channel walls is investigated by numerical simulation. A two-dimensional phase diagram with at least four different behaviors is constructed. The fouling is modeled by attachment during collision with the deposits and by detachment caused by large enough hydrodynamic drag. For fixed total number of particles and small Reynolds numbers, the relevant parameters governing the fouling dynamics are the solid volume fraction of the suspension and the detachment drag force threshold. Below a critical curve in this 2D phase space only transient fouling takes place when the suspension is accelerated from rest by a pressure gradient. Above the fouling transition line, persistent fouling layers are formed via ballistic deposition for low and via homogeneous deposition for large solid volume fractions. Close to the fouling transition line, the flow path between the deposited layers meanders, while necking appears for increasing distance from the transition. Finally, another transition to a fully blocked flow path takes place. As determined by the estimated amount of deposited particles at saturation, both transitions seem to be discontinuous. Large fluctuations and long saturation times are typical of the dynamics of the system.

  10. Polymorphism in Bacterial Flagella Suspensions

    NASA Astrophysics Data System (ADS)

    Schwenger, Walter J.

    Bacterial flagella are a type of biological polymer studied for its role in bacterial motility and the polymorphic transitions undertaken to facilitate the run and tumble behavior. The naturally rigid, helical shape of flagella gives rise to novel colloidal dynamics and material properties. This thesis studies methods in which the shape of bacterial flagella can be controlled using in vitro methods and the changes the shape of the flagella have on both single particle dynamics and bulk material properties. We observe individual flagellum in both the dilute and semidilute regimes to observe the effects of solvent condition on the shape of the filament as well as the effect the filament morphology has on reptation through a network of flagella. In addition, we present rheological measurements showing how the shape of filaments effects the bulk material properties of flagellar suspensions. We find that the individual particle dynamics in suspensions of flagella can vary with geometry from needing to reptate linearly via rotation for helical filaments to the prevention of long range diffusion for block copolymer filaments. Similarly, for bulk material properties of flagella suspensions, helical geometries show a dramatic enhancement in elasticity over straight filaments while block copolymers form an elastic gel without the aid of crosslinking agents.

  11. Membrane filtration of food suspensions.

    PubMed Central

    Sharpe, A N; Peterkin, P I; Dudas, I

    1979-01-01

    Factors affecting the membrane filtration of food suspensions were studied for 58 foods and 13 membrane filters. Lot number within a brand, pore size (0.45 or 0.8 micrometer), and time elapsed before filtration had little effect on filterability. Brand of membrane filter, flow direction, pressure differential, age (microbiological quality) of the food, duration of the blending process, temperature, and concentration of food in the suspension had significant and often predictable effects. Preparation of suspensions by Stomacher (relative to rotary blender) addition of surfactant (particularly at elevated temperature) and prior incubation with proteases sometimes had dramatic effects of filterability. In contrast to popular opinion, foods can be membrane filtered in quantities pertinent to the maximums used in conventional plating procedures. Removal of growth inhibitors and food debris is possible by using membrane filters. Lowering of the limits of detection of microorganisms by concentration on membrane filters can be considered feasible for many foods. The data are particularly relevant to the use of hydrophobic grid-membrane filters (which are capable of enumerating up to 9 X 10(4) organisms per filter) in instrumented methods of food microbiological analysis. Images PMID:760637

  12. Contact angle hysteresis of microbead suspensions.

    PubMed

    Waghmare, Prashant R; Mitra, Sushanta K

    2010-11-16

    Microbead suspensions are often used in microfluidic devices for transporting biomolecules. An experimental investigation on the wettability of microbead suspension is presented in this study. The variation in the surface tension and the equilibrium contact angle with the change in the volume fraction of the microbead is presented here. The surface tension of the microbead suspension is measured with the pendant drop technique, whereas the dynamic contact angle measurements, i.e., advancing and receding contact angles, are measured with the sessile drop technique. An equilibrium contact angle of a suspension with particular volume fraction is determined by computing an average over the measured advancing and receding contact angles. It is observed that the surface tension and the equilibrium contact angle determined from advancing and receding contact angles vary with the magnitude of the microbeads volume fraction in the suspension. A decrease in the surface tension with an increase in the volume fraction of the microbead suspension is observed. The advancement and the recession in contact line for dynamic contact angle measurements are achieved with the motorized dosing mechanism. For microbead suspensions, the advancement of the contact line is faster as compared to the recession of the contact line for the same flow rate. The presence of microbeads assists in the advancement and the recession of the contact line of the suspension. A decrease in the equilibrium contact angles with an increase in the microbead suspension volume fraction is observed. Inclusion of microbeads in the suspension increases the wetting capability for the considered combination of the microbead suspension and substrate. Finally, empirical correlations for the surface tension and the contact angle of the suspension as a function of microbead volume fraction are proposed. Such correlations can readily be used to develop mechanistic models for the capillary transport of microbead

  13. Real-time monitoring of suspension cell-cell communication using an integrated microfluidics.

    PubMed

    Xu, Tao; Yue, Wanqing; Li, Cheuk-Wing; Yao, Xinsheng; Cai, Guoping; Yang, Mengsu

    2010-09-07

    For the first time, we have developed a microfluidic device for on-chip monitoring of suspension cell-cell communication from stimulated to recipient HL-60 cells. A deformable PDMS membrane was developed as a compressive component to perform cell entrapment and exert different modes of mechanical stimulation. The number of cells trapped by this component could be modulated by flushing excessive cells towards the device outlet. The trapped cells could be triggered to release mediators by mechanical stimulation. Sandbag microstructures were used to immobilize recipient cells at well-defined positions. These recipient cells were evoked by mediators released from mechanically stimulated cells trapped in the compressive component. Normally closed microvalves were integrated to provide continuous-flow and static environment. We studied cell-cell communication between stimulated (in compressive component) and recipient (in sandbag structures) cells. Calcium oscillations were observed in some recipient cells only when a low number of cells were stimulated. Different mechanical stimulation and flow environment were also employed to study their impact on the behavior of cell-cell communication. We observed that both the duration and intensity of intracellular calcium responses increased in persistent stimulation and decreased in flowing environment. This microdevice may open up new avenues for real-time monitoring of suspension cell-cell communication, which propagates via gap-junction independent mechanism, with multiple variables under control.

  14. Silicon mirror suspensions for gravitational wave detectors

    NASA Astrophysics Data System (ADS)

    Cumming, A. V.; Cunningham, L.; Hammond, G. D.; Haughian, K.; Hough, J.; Kroker, S.; Martin, I. W.; Nawrodt, R.; Rowan, S.; Schwarz, C.; van Veggel, A. A.

    2014-01-01

    One of the most significant limits to the sensitivity of current, and future, long-baseline interferometric gravitational wave detectors is thermal displacement noise of the test masses and their suspensions. This paper reports results of analytical and experimental studies of the limits to thermal noise performance of cryogenic silicon test mass suspensions set by two constraints on suspension fibre dimensions: the minimum dimensions required to allow conductive cooling for extracting incident laser beam heat deposited in the mirrors; and the minimum dimensions of fibres (set by their tensile strength) which can support test masses of the size envisaged for use in future detectors. We report experimental studies of breaking strength of silicon ribbons, and resulting design implications for the feasibility of suspension designs for future gravitational wave detectors using silicon suspension fibres. We analyse the implication of this study for thermal noise performance of cryogenically cooled silicon suspensions.

  15. Magnetic suspension systems for space applications

    NASA Technical Reports Server (NTRS)

    Havenhill, Douglas G.; Wolke, Patrick J.

    1991-01-01

    An overview of techniques is presented used in the described magnetic suspension systems. Also a review is presented of the systems already developed, which demonstrate the usefulness, applicability, and flight readiness of magnetic suspension to a broad range of payloads and environments. The following subject areas are covered: programs overview; key concepts; magnetic suspension as an isolator and as a pointer; pointing and isolation systems; magnetic actuator control techniques; and test data.

  16. Large angle magnetic suspension text fixture

    NASA Technical Reports Server (NTRS)

    Britcher, Colin P.

    1995-01-01

    In lieu of a final report for this project for the period 1 April 1995 through 31 October 1995, a compilation of three reports are included herein. The three reports are: (1) 'Design and Implementation of a Digital Controller for a Magnetic Suspension and Vernier Pointing System', (2) 'Influence of Eddy Currents on the Dynamic Characteristics of Magnetic Suspensions and Magnetic Bearings', and (3) 'Design and Implementation of a Digital Controller for a Magnetic Suspension and Vernier Pointing System'.

  17. Attractive and repulsive magnetic suspension systems overview

    NASA Technical Reports Server (NTRS)

    Cope, David B.; Fontana, Richard R.

    1992-01-01

    Magnetic suspension systems can be used in a wide variety of applications. The decision of whether to use an attractive or repulsive suspension system for a particular application is a fundamental one which must be made during the design process. As an aid to the designer, we compare and contrast attractive and repulsive magnetic suspension systems and indicate whether and under what conditions one or the other system is preferred.

  18. Ultrasonic characterization of solid liquid suspensions

    DOEpatents

    Panetta, Paul D.

    2010-06-22

    Using an ultrasonic field, properties of a solid liquid suspension such as through-transmission attenuation, backscattering, and diffuse field are measured. These properties are converted to quantities indicating the strength of different loss mechanisms (such as absorption, single scattering and multiple scattering) among particles in the suspension. Such separation of the loss mechanisms can allow for direct comparison of the attenuating effects of the mechanisms. These comparisons can also indicate a model most likely to accurately characterize the suspension and can aid in determination of properties such as particle size, concentration, and density of the suspension.

  19. Modeling of Electromagnetic Damper for Automobile Suspension

    NASA Astrophysics Data System (ADS)

    Kawamoto, Yasuhiro; Suda, Yoshihiro; Inoue, Hirofumi; Kondo, Takuhiro

    In this paper, the modeling of the electromagnetic damper (EMD) for automobile suspension is presented and the validation of the model is demonstrated by comparing the numerical results with the experimental results obtained using shaker tests. EMD is used as an active suspension and controlled to have output force calculated from velocities of sprung and unsprung masses. The formulation of EMD system for active suspensions is first developed, and the validation of the EMD model is demonstrated by experiments of the EMD for automobile suspensions. The validity of the formulation of the EMD developed in this investigation is shown for the frequency responses as well as energy balance for its active use.

  20. Electromagnetic suspension and levitation techniques

    NASA Astrophysics Data System (ADS)

    Jayawant, B. V.

    1988-04-01

    A comprehensive account is given of state-of-the-art and prospective electromagnetic and electromechanical suspension/levitation technologies, using both conventional and superconducting materials, with a view both to their performance improvements over differently grounded technologies and their economic feasibility. In addition to passenger-carrying vehicles, controlled DC electromagnet technologies have been applied to frictionless magnetic bearings, flow meters, conveyor systems, high-speed machine tool spindles, ultracentrifuges, turboalternators, corrosive-liquid pumps, gas compressors, high-vacuum pumps, and energy storage flywheels. Attention is given to the commercial prospects for devices based on superconducting magnets.

  1. Single element magnetic suspension actuator

    NASA Technical Reports Server (NTRS)

    Groom, Nelson J. (Inventor)

    1991-01-01

    The invention, a single element magnetic suspension actuator with bidirectional force capability along a single axis, includes an electromagnet and a nonmagnetic suspended element. A permanent magnet mounted on the suspended element interacts with a magnetic field established by the electromagnet to produce bidirectional forces in response to a variable force command voltage V (sub FC) applied to the electromagnet. A sensor measures the position of the suspended element on the single axis which is a function of force command voltage V (sub FC).

  2. Magnetic suspension options for spacecraft inertia-wheel applications

    NASA Technical Reports Server (NTRS)

    Downer, J. R.

    1984-01-01

    Design criteria for spacecraft inertia-wheel suspensions are listed. The advantages of magnetic suspensions over other suspension types for spacecraft inertia-wheel applications are cited along with the functions performed by magnetic suspension. The common designs for magnetic suspensions are enumerated. Materials selection of permanent magnets and core materials is considered.

  3. Frozen ZnS Aqueous Suspension Nonlinear Optical Properties

    NASA Astrophysics Data System (ADS)

    Ehrlich, H.; Kudryavtseva, A.; Lisichkin, G.; Savranskii, V.; Tcherniega, N.; Zemskov, K.; Zhilenko, M.

    2015-11-01

    The study of nonlinear effects, caused by nanosecond laser pulses' impact on the frozen ZnS nanoparticles' suspension, is presented. Laser pulses excite strong nanoparticles' coherent vibrations in the near-terahertz range which lead to different nonlinear effects: X-ray emission, stimulated low-frequency Raman scattering, and luminescence. X-ray emission was observed as bright spots on the special X-ray film. This provides evidence that an X-ray propagates with narrow beams. Stimulated low-frequency Raman scattering is a result of light scattering by acoustic vibrations of nanoparticles. Its frequency shift corresponds to the nanoparticles' eigenvibration frequencies and depends on the sample material and particle's dimension. It was measured with the help of a Fabri-Perot interferometer in the range of dispersion 16.67 {cm}^{-1}. For ZnS, the first Stokes component frequency shift is equal to 465 GHz. Under excitation by 20 ns ruby laser pulses, the luminescence of the frozen ZnS nanoparticles' suspension was observed in two bands located at 480 nm and 510 nm. Its duration was more than 3 s.

  4. Elicitation of andrographolide in the suspension cultures of Andrographis paniculata.

    PubMed

    Gandi, Suryakala; Rao, Kiranmayee; Chodisetti, Bhuvaneswari; Giri, Archana

    2012-12-01

    Andrographis paniculata belonging to the family Acanthaceae produces a group of diterpene lactones, one of which is the pharmaceutically important-andrographolide. It is known to possess various important biological properties like anticancer, anti-HIV, anti-inflammatory, etc. This is the first report on the production of andrographolide in the cell suspension cultures of Andrographis paniculata by 'elicitation'. Elicitation was attempted to enhance the andrographolide content in the suspension cultures of Andrographis paniculata and also to ascertain its stimulation under stress conditions or in response to pathogen attack. The maximum andrographolide production was found to be 1.53 mg/g dry cell weight (DCW) at the end of stationary phase during the growth curve. The biotic elicitors (yeast, Escherichia coli, Bacillus subtilis, Agrobacterium rhizogenes 532 and Agrobacterium tumefaciens C 58) were more effective in eliciting the response when compared to the abiotic elicitors (CdCl(2), AgNO(3), CuCl(2) and HgCl(2)). Yeast has shown to stimulate maximum accumulation of 13.5 mg/g DCW andrographolide, which was found to be 8.82-fold higher than the untreated cultures.

  5. 46 CFR 565.10 - Suspension procedures, period of suspension, and replacement rates.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 9 2010-10-01 2010-10-01 false Suspension procedures, period of suspension, and replacement rates. 565.10 Section 565.10 Shipping FEDERAL MARITIME COMMISSION REGULATIONS AND ACTIONS TO ADDRESS RESTRICTIVE FOREIGN MARITIME PRACTICES CONTROLLED CARRIERS § 565.10 Suspension procedures, period...

  6. Decreasing School Suspensions among Middle School Children by Implementing a Rehabilitative In-Room Suspension.

    ERIC Educational Resources Information Center

    Novell, Ireneanne

    This practicum report describes a 15-day in-room suspension strategy designed to reduce the increasing number of principal-initiated student suspensions resulting from inappropriate conduct. The program's distinguishing features entailed a central figure who predetermined the candidates by means of a pre-suspension interview, parental-student…

  7. Stimulating Curiosity.

    ERIC Educational Resources Information Center

    Necka, Edward

    1989-01-01

    Curiosity can be developed and nurtured through application of such educational principles as the rewarding of questioning, the use of open questions, delaying answers, accepting incompleteness in existing knowledge, etc. Teaching techniques for stimulating curiosity include brain questioning, role playing, hypothesizing, and pursuing curiosity.…

  8. Migrational Instabilities in Particle Suspensions

    NASA Technical Reports Server (NTRS)

    Goddard, Joe D.

    1996-01-01

    This work deals with an instability arising from the shear-induced migration of particles in dense suspensions coupled with a dependence of viscosity on particle concentration. The analysis summarized here treats the inertialess (Re = O) linear stability of homogeneous simple shear flows for a Stokesian suspension model of the type proposed by Leighton and Acrivos (1987). Depending on the importance of shear-induced migration relative to concentration-driven diffusion, this model admits short-wave instability arising from wave-vector stretching by the base flow and evolving into particle-depleted shear bands. Moreover, this instability in the time-dependent problem corresponds to loss of ellipticity in the associated static problem (Re = O, Pe = O). While the isotropic version of the Leighton-Acrivos model is found to be stable with their experimentally determined parameters for simple shear, it is known that the stable model does not give a good quantitative description of particle clustering in the core of pipe flow (Nott and Brady 1994). This leads to the conjecture that an appropriate variant on the above model could explain such clustering as a two-phase bifurcation in the base flow.

  9. Photomixing of chlamydomonas rheinhardtii suspensions

    NASA Astrophysics Data System (ADS)

    Dervaux, Julien; Capellazzi Resta, Marina; Abou, Bérengère; Brunet, Philippe

    2014-11-01

    Chlamydomonas rheinhardtii is a fast swimming unicellular alga able to bias its swimming direction in gradients of light intensity, an ability know as phototaxis. We have investigated experimentally both the swimming behavior of individual cells and the macroscopic response of shallow suspensions of these micro-organisms in response to a localized light source. At low light intensity, algae exhibit positive phototaxis and accumulate beneath the excitation light. In weakly concentrated thin layers, the balance between phototaxis and cell motility results in steady symmetrical patterns compatible with a purely diffusive model using effective diffusion coefficients extracted from the analysis of individual cell trajectories. However, at higher cell density and layer depth, collective effects induce convective flows around the light source. These flows disturb the cell concentration patterns which spread and may then becomes unstable. Using large passive tracer particles, we have characterized the velocity fields associated with this forced bioconvection and their dependence on the cell density and layer depth. By tuning the light distribution, this mechanism of photo-bioconvection allows a fine control over the local fluid flows, and thus the mixing efficiency, in algal suspensions.

  10. Brain Stimulation Therapies

    MedlinePlus

    ... Magnetic Seizure Therapy Deep Brain Stimulation Additional Resources Brain Stimulation Therapies Overview Brain stimulation therapies can play ... for a shorter recovery time than ECT Deep Brain Stimulation Deep brain stimulation (DBS) was first developed ...

  11. Effective temperature for sheared suspensions: a route towards closures for migration in bidisperse suspension.

    PubMed

    van der Sman, R G M; Vollebregt, H M

    2012-12-01

    By extending the concept of an effective temperature, earlier introduced for sheared monodisperse suspensions, we propose a continuum theory for sheared bidisperse suspensions. We show the theory for sheared suspensions can be constructed from the theory for Brownian suspensions by replacing the temperature with the effective temperature. Furthermore, we explore the validity of closure relations based on mean field/free volume theory, by comparison with experimental data obtained for Brownian bidisperse suspensions. In a recent paper, we have shown that the new theory, combined with the discussed closure relations, is indeed a predictive theory.

  12. 34 CFR 85.1015 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 34 Education 1 2010-07-01 2010-07-01 false Suspension. 85.1015 Section 85.1015 Education Office of the Secretary, Department of Education GOVERNMENTWIDE DEBARMENT AND SUSPENSION (NONPROCUREMENT..., pending completion of an agency investigation and any judicial or administrative proceedings that may...

  13. 49 CFR 238.227 - Suspension system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Suspension system. 238.227 Section 238.227 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Equipment § 238.227 Suspension system. On or after November 8, 1999— (a) All passenger equipment shall...

  14. 25 CFR 23.52 - Grant suspension.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Grant suspension. 23.52 Section 23.52 Indians BUREAU OF... Grant Administration Provisions and Requirements § 23.52 Grant suspension. (a) When a grantee has materially failed to comply and remains out of compliance with the terms and conditions of the grant, the...

  15. 25 CFR 23.52 - Grant suspension.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Grant suspension. 23.52 Section 23.52 Indians BUREAU OF... Grant Administration Provisions and Requirements § 23.52 Grant suspension. (a) When a grantee has materially failed to comply and remains out of compliance with the terms and conditions of the grant, the...

  16. 49 CFR 238.227 - Suspension system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Suspension system. 238.227 Section 238.227 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Equipment § 238.227 Suspension system. On or after November 8, 1999— (a) All passenger equipment shall...

  17. 49 CFR 385.911 - Suspension proceedings.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 5 2014-10-01 2014-10-01 false Suspension proceedings. 385.911 Section 385.911 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY... Pattern or Practice of Safety Violations by Motor Carrier Management § 385.911 Suspension proceedings. (a...

  18. Suspension System Provides Independent Translation And Rotation

    NASA Technical Reports Server (NTRS)

    Heeg, Jennifer

    1994-01-01

    Spring suspension provides one translational and one rotational degree of freedom. Suspension used to provide for pitching and plunging movements of airfoil in wind tunnel. Translational freedom provided by two thin, flat steel spring tines, clamped at one end to stationary block fixed to ceiling of wind tunnel, and clamped to movable block at other end.

  19. Ultrasonic characterization of shear thickening suspensions

    NASA Astrophysics Data System (ADS)

    Johnson, Benjamin Lenihan

    This dissertation describes the characterization of an inherently inhomogeneous medium capable of shear thickening. An aqueous suspension of cornstarch represents an important exemplar of such physical systems. The physics underlying the behavior of such shear thickening suspensions is incompletely understood. Characterization of these suspensions may provide valuable clues into the underlying mechanisms that result in shear thickening behavior. The goal of this thesis is to characterize the acoustic properties of suspensions of cornstarch in density-matched cesium chloride aqueous solutions. A review of the literature indicated that almost no information concerning the ultrasonic characteristics of suspensions of starches had been reported other than studies monitoring the gelatinization of starches not relevant to the shear stiffening of ungelatinized suspensions. Each chapter began with a discussion and validation of the specific experimental techniques and methods of analysis necessary for each type of measurement. Ultrasonic measurement of the group velocity, the frequency-dependent attenuation properties, the frequency-dependent phase velocity, and the frequency-dependent backscatter properties of the suspensions of cornstarch are reported. Initially counterintuitive results including negative (phase velocity) dispersion and a decrease in the measured backscatter coefficient with increasing particle concentration are understood in terms of widely accepted physical models. In sum, these studies represent an advancement of the understanding of the physics underlying the interaction between ultrasound and suspensions and lay the groundwork for future studies probing the physics of the shear thickening.

  20. 49 CFR 238.227 - Suspension system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Suspension system. 238.227 Section 238.227 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Equipment § 238.227 Suspension system. On or after November 8, 1999— (a) All passenger equipment shall...

  1. Alternatives to Suspension: A Government Initiative

    ERIC Educational Resources Information Center

    Ryan, Thomas G.; Zoldy, Scott

    2011-01-01

    Student discipline and the ineffectiveness of out-of-school suspension is examined in light of the Ontario (Canada) legislative reform that supported a greater emphasis on progressive discipline alternatives to out-of-school suspension. Alternative discipline herein is explored via the behavior education plan, the school survival group, and…

  2. Stability of compounded thioguanine oral suspensions.

    PubMed

    Aliabadi, Hamidreza Montazeri; Romanick, Marcel; Somayaji, Vishwa; Mahdipoor, Parvin; Lavasanifar, Afsaneh

    2011-05-15

    PURPOSE. Updated information on the stability of compounded thioguanine oral suspensions prepared with currently available ingredients, as well as results of testing to determine if the addition of an antioxidant could extend shelf life by inhibiting formation of guanine, are presented. METHODS. Using triturated thioguanine tablets, three compounded suspensions were prepared: (1) a reference formulation containing methylcellulose and simple syrup, (2) an equivalent formulation using Ora-Plus and Ora-Sweet, and (3) an antioxidant-containing formulation prepared by adding ascorbic acid to the equivalent formulation. The compounded batches were stored at room temperature (19-23 °C). The chemical stability of the suspensions was evaluated immediately after compounding and at weekly intervals by a validated liquid chromatography-mass spectrometry (LCMS) assay method; physical stability was evaluated by regular visual checks and weekly pH testing. RESULTS. As demonstrated by serial LCMS testing, mean thioguanine levels in sampled batches of all three suspensions remained above accepted standards and mean guanine formation remained within acceptable limits for up to 63 days. The addition of ascorbic acid appeared to slow guanine formation but did not significantly extend the shelf life of the suspension. CONCLUSION. Compounded oral suspensions of thioguanine 20 mg/mL exhibited acceptable chemical and physical stability for up to nine weeks at 19-23 °C. The addition of ascorbic acid at a concentration of 0.1% to the suspension was not effective in consistently increasing the shelf life of the thioguanine suspensions.

  3. Large Angle Magnetic Suspension Test Fixture

    NASA Technical Reports Server (NTRS)

    Britcher, Colin P.; Huang, Jen-Kuang

    1997-01-01

    Progress in the areas of eddy current computations, modelling and analysis, design optimization methods, wind tunnel Magnetic Suspension and Balance Systems (MSBS), payload pointing and vibration isolation systems, and system identification is reported. Research accomplishments facilitated the demonstration of several new developments in the field of magnetic suspension technology.

  4. 39 CFR 955.28 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Suspension. 955.28 Section 955.28 Postal Service UNITED STATES POSTAL SERVICE PROCEDURES RULES OF PRACTICE BEFORE THE POSTAL SERVICE BOARD OF CONTRACT APPEALS § 955.28 Suspension. (a) Whenever at any time it appears that the parties are in agreement as to...

  5. 41 CFR 105-74.670 - Suspension.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false Suspension. 105-74.670 Section 105-74.670 Public Contracts and Property Management Federal Property Management Regulations System...-GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 105-74.670 Suspension...

  6. 41 CFR 105-74.670 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Suspension. 105-74.670 Section 105-74.670 Public Contracts and Property Management Federal Property Management Regulations System...-GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (FINANCIAL ASSISTANCE) Definitions § 105-74.670 Suspension...

  7. 25 CFR 242.7 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Suspension. 242.7 Section 242.7 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE COMMERCIAL FISHING ON RED LAKE INDIAN RESERVATION § 242.7 Suspension. All commercial fishing operations may be suspended by order of the Secretary at...

  8. 32 CFR 1609.5 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Suspension. 1609.5 Section 1609.5 National Defense Other Regulations Relating to National Defense SELECTIVE SERVICE SYSTEM UNCOMPENSATED PERSONNEL § 1609.5 Suspension. The Director of Selective Service may suspend from duty any uncompensated...

  9. 77 FR 61518 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-10

    ... for suspension because of its failure to adopt compliant floodplain management regulations under the... effective suspension date, indicating it has brought its floodplain management program into compliance with... generally not otherwise available. In return, communities agree to adopt and implement local floodplain...

  10. 49 CFR 393.207 - Suspension systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... braking system. The vehicle shall be level (not tilting to the left or right). Air leakage shall not be... 49 Transportation 5 2013-10-01 2013-10-01 false Suspension systems. 393.207 Section 393.207... NECESSARY FOR SAFE OPERATION Frames, Cab and Body Components, Wheels, Steering, and Suspension Systems §...

  11. 49 CFR 393.207 - Suspension systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... braking system. The vehicle shall be level (not tilting to the left or right). Air leakage shall not be... 49 Transportation 5 2014-10-01 2014-10-01 false Suspension systems. 393.207 Section 393.207... NECESSARY FOR SAFE OPERATION Frames, Cab and Body Components, Wheels, Steering, and Suspension Systems §...

  12. 49 CFR 393.207 - Suspension systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... braking system. The vehicle shall be level (not tilting to the left or right). Air leakage shall not be... 49 Transportation 5 2012-10-01 2012-10-01 false Suspension systems. 393.207 Section 393.207... NECESSARY FOR SAFE OPERATION Frames, Cab and Body Components, Wheels, Steering, and Suspension Systems §...

  13. 45 CFR 1206.1-4 - Suspension.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... adequately correct the deficiency which led to the initiation of the suspension proceeding. (9) The... section as well as any showing that the recipient has adequately corrected the deficiency which led to the... adequately corrected the deficiency which led to the suspension and that repetition is not...

  14. 25 CFR 23.52 - Grant suspension.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Grant suspension. 23.52 Section 23.52 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR HUMAN SERVICES INDIAN CHILD WELFARE ACT General and Uniform Grant Administration Provisions and Requirements § 23.52 Grant suspension. (a) When a grantee...

  15. 25 CFR 23.52 - Grant suspension.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Grant suspension. 23.52 Section 23.52 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR HUMAN SERVICES INDIAN CHILD WELFARE ACT General and Uniform Grant Administration Provisions and Requirements § 23.52 Grant suspension. (a) When a grantee...

  16. Viscosity of Sheared Helical filament Suspensions

    NASA Astrophysics Data System (ADS)

    Sartucci, Matthew; Urbach, Jeff; Blair, Dan; Schwenger, Walter

    The viscosity of suspensions can be dramatically affected by high aspect ratio particles. Understanding these systems provides insight into key biological functions and can be manipulated for many technological applications. In this talk, the viscosity as a function of shear rate of suspensions of helical filaments is compared to that of suspensions of straight rod-like filaments. Our goal is to determine the impact of filament geometry on low volume fraction colloidal suspensions in order to identify strategies for altering viscosity with minimal volume fraction. In this research, the detached flagella of the bacteria Salmonella Typhimurium are used as a model system of helical filaments and compared to mutated straight flagella of the Salmonella. We compare rheological measurements of the suspension viscosity in response to shear flow and use a combination of the rheology and fluorescence microscopy to identify the microstructural changes responsible for the observed rheological response.

  17. Coupling suspension complex system optimization

    NASA Astrophysics Data System (ADS)

    English, Kenneth William

    The design of a complex product requires multiple analyses, many of which trade information. In some cases, some information is required before it is available, as a result an estimate must be made of that input for the analysis to proceed. Once the input becomes available, additional calculations must be made to ensure that the result of the analysis reflects the changed input. This iteration creates a considerable computational cost in the design process. This iteration may be eliminated through the reordering of the analyses, or through the temporary or permanent removal of the couplings between the system analyses. This elimination of couplings is termed system reduction. Until relatively recently, the trade of accuracy and efficiency that enables system reduction was only carried out in the context of local sensitivities, how much one analysis output impacts another output. Recent developments expanded this capability to include a system level measure of introduced error into the objective function and constraints, allowing the development of a selection subproblem that trades accuracy and efficiency in the system reduction context. The current state of the trade-off between accuracy and efficiency is far form complete. The initial subproblem formulation resulted in potentially destabilizing sets of couplings being selected, which could result in system analysis convergence errors. Additionally, the technique employed to select couplings for suspension is extremely limited in scope. The designer's intuition and experience had been eliminated from the selection process, replaced by a simple selection algorithm. First, the current coupling suspension problem is augmented, incorporating additional constraints to improve performance in system analysis stability, improved convergence characteristics, and more accurate error growth modeling. The second issue this dissertation addresses is the development of a methodology that allows a designer to interactively

  18. INCIPIENT GERMINATION IN HEAVY SUSPENSIONS OF SPORES OF BACILLUS STEAROTHERMOPHILUS AT SUBMINIMAL GROWTH TEMPERATURES

    PubMed Central

    Curran, Harold R.; Pallansch, Michael J.

    1963-01-01

    Curran, Harold R. (U.S. Department of Agriculture, Washington, D.C.), and Michael J. Pallansch. Incipient germination in heavy suspensions of spores of Bacillus stearothermophilus at subminimal growth temperatures. J. Bacteriol. 86:911–918. 1963.—By use of spore (plate) counts and permeability to stain, labilization was followed periodically in heavy suspensions of washed Bacillus stearothermophilus 1518 spores incubated at different temperatures. Although vegetative proliferation did not occur below 38 C, incipient germination was rapid down to 20 C and much slower and incomplete at 14 C. Dilution of the suspension materially reduced the degree and rate of labilization. The degree of washing and use of deionized water had no appreciable influence upon early development of the spores. The results are discussed from the point of view of the possible origin and nature of the germination stimulant. Images PMID:14080801

  19. Next Generation Suspension Dynamics Algorithms

    SciTech Connect

    Schunk, Peter Randall; Higdon, Jonathon; Chen, Steven

    2014-12-01

    This research project has the objective to extend the range of application, improve the efficiency and conduct simulations with the Fast Lubrication Dynamics (FLD) algorithm for concentrated particle suspensions in a Newtonian fluid solvent. The research involves a combination of mathematical development, new computational algorithms, and application to processing flows of relevance in materials processing. The mathematical developments clarify the underlying theory, facilitate verification against classic monographs in the field and provide the framework for a novel parallel implementation optimized for an OpenMP shared memory environment. The project considered application to consolidation flows of major interest in high throughput materials processing and identified hitherto unforeseen challenges in the use of FLD in these applications. Extensions to the algorithm have been developed to improve its accuracy in these applications.

  20. Introduction to suspension levels: radiotherapy.

    PubMed

    Horton, P; Lillicrap, S; Lamm, I-L; Lehmann, W

    2013-02-01

    In 2007, the European Commission (EC) commissioned a group of experts to undertake the revision of Report Radiation Protection (RP 91) 'Criteria for acceptability of radiological (including radiotherapy) and nuclear medicine installations' written in 1997. The revised draft report was submitted to the EC in 2010, who issued it for public consultation. The EC has commissioned the same group of experts to consider the comments of the public consultation for further improvement of the revised report. The EC intends to publish the final report under its Radiation Report Series as RP 162. This paper describes the background to the selection of the key performance parameters for radiotherapy equipment and sets out the sources of their criteria of acceptability including suspension levels for a wide range of radiotherapy equipment.

  1. Evaporation in dense suspension droplets

    NASA Astrophysics Data System (ADS)

    Kim, Jin Young; Weon, Byung Mook

    2014-11-01

    When a drop on a solid surface dries, a variety of drying dynamics emerge eventually. Here we show how colloidal particles affect drying dynamics in colloidal suspensions. By comparing drying dynamics of pure and colloidal fluids using confocal microscopy and mass balance, we demonstrate that the drying dynamics of colloidal fluids strongly depend on the colloid size and the initial concentration. The role of colloidal particles is complicated in the drying processes and related to the hydrodynamics for the porous medium. This work would offer clues for the dynamic nature of colloidal fluids and help to understand the drying-mediated processes such as spreading, painting, coating, and evapotranspiration. This work (NRF-2013R1A22A04008115) was supported by Mid-career Researcher Program through NRF grant funded by the MEST.

  2. Shear thinning of nanoparticle suspensions.

    SciTech Connect

    Grest, Gary Stephen; Petersen, Matthew K.; in't Veld, Pieter J.

    2008-08-01

    Results of large scale non-equilibrium molecular dynamics (NEMD) simulations are presented for nanoparticles in an explicit solvent. The nanoparticles are modeled as a uniform distribution of Lennard-Jones particles, while the solvent is represented by standard Lennard-Jones particles. Here we present results for the shear rheology of spherical nanoparticles of size 5 to 20 times that of the solvent for a range of nanoparticle volume fractions and interactions. Results from NEMD simulations suggest that for strongly interacting nanoparticle that form a colloidal gel, the shear rheology of the suspension depends only weakly on the size of the nanoparticle, even for nanoparticles as small as 5 times that of the solvent. However for hard sphere-like colloids the size of the nanoparticles strongly affects the shear rheology. The shear rheology for dumbbell nanoparticles made of two fused spheres is also compared to spherical nanoparticles and found to be similar except at very high volume fractions.

  3. Naratriptan hydrochloride in extemporaneosly compounded oral suspensions.

    PubMed

    Zhang, Y P; Trissel, L A; Fox, J L

    2000-01-01

    The purpose of this study was to determine the pharmaceutical acceptability and chemical stability of naratriptan hydrochloride in three extemporaneously compounded suspension formulations. The naratriptan-hydrochloride oral suspensions were prepared from 2.5-mg commercial tablets yielding a nominal naratriptan concentration of 0.5 mg/mL. The suspension vehicles selected for testing were Syrpalta, an equal-parts mixture of Ora-Plus and Ora-Sweet, and an equal-parts mixture of Ora-Plus and Ora-Sweet SF. The tablets were crushed and thoroughly triturated to a fine powder using a porcelain mortar and pestle. The powder was incorporated into a portion of the Syrpalta or Ora-Plus suspension vehicle and mixed until homogeneous. The mixtures were then brought to volume with Syrpalta, Ora-Sweet or Ora-Sweet SF, as appropriate. The suspensions were packaged in amber, plastic, screw-cap prescription bottles and stored at 23 deg C for seven days and 4 deg C for 90 days. An adequate suspension was never achieved in Syrpalta. The crushed-tablet powder did not produce a uniformly dispersed mixture and exhibited clumping and a high rate of sedimentation. A distinct layer of the solid tablet material settled immediately after shaking. Over the next four hours, a densely packed, yellow, caked layer formed at the bottom of the containers, making resuspension difficult. During storage, the caking became worse. Chemical analysis was not performed. The Ora-Plus and Ora-Sweet or Ora-Sweet SF suspensions had a slight greenish cast and were resuspended without difficulty by shaking for approximately ten seconds, yielding easily poured and homogeneous mixtures throughout the study. Visible settling and layering did not begin for four hours with the Ora-Sweet suspension and 24 hours for the Ora-Sweet SF suspension. High pressure liquid chromatographic analysis found that the naratriptan concentration in both suspension-vehicle combinations exhibited little or no loss for seven days at 23

  4. Self-powered suspension criterion and energy regeneration implementation scheme of motor-driven active suspension

    NASA Astrophysics Data System (ADS)

    Yan, Shuai; Sun, Weichao

    2017-09-01

    Active suspension systems have advantages on mitigating the effects of vehicle vibration caused by road roughness, which are one of the most important component parts in influencing the performances of vehicles. However, high amount of energy consumption restricts the application of active suspension systems. From the point of energy saving, this paper presents a self-powered criterion of the active suspension system to judge whether a motor-driven suspension can be self-powered or not, and then a motor parameter condition is developed as a reference to design a self-powered suspension. An energy regeneration implementation scheme is subsequently proposed to make the active suspension which has the potential to be self-powered achieve energy-saving target in the real application. In this implementation scheme, operating electric circuits are designed based on different working status of the actuator and power source and it is realizable to accumulate energy from road vibration and supply energy to the actuator by switching corresponding electric circuits. To apply the self-powered suspension criterion and energy regeneration implementation scheme, an active suspension system is designed with a constrained H∞ controller and calculation results indicate that it has the capability to be self-powered. Simulation results show that the performances of the self-powered active suspension are nearly the same as those of the active suspension with an external energy source and can achieve energy regeneration at the same time.

  5. Restructuring and aging in a capillary suspension

    PubMed Central

    Koos, Erin; Kannowade, Wolfgang; Willenbacher, Norbert

    2014-01-01

    The rheological properties of capillary suspensions, suspensions with small amounts of an added immiscible fluid, are dramatically altered with the addition of the secondary fluid. We investigate a capillary suspension to determine how the network ages and restructures at rest and under applied external shear deformation. The present work uses calcium carbonate suspended in silicone oil (11 % solids) with added water as a model system. Aging of capillary suspensions and their response to applied oscillatory shear is distinctly different from particulate gels dominated by the van der Waals forces. The suspensions dominated by the capillary force are very sensitive to oscillatory flow, with the linear viscoelastic regime ending at a deformation of only 0.1% and demonstrating power-law aging behavior. This aging persists for long times at low deformations or for shorter times with a sudden decrease in the strength at higher deformations. This aging behavior suggests that the network is able to rearrange and even rupture. This same sensitivity is not demonstrated in shear flow where very high shear rates are required to rupture the agglomerates returning the apparent viscosity of capillary suspensions to the same viscosity as for the pure vdW suspension. A transitional region is also present at intermediate water contents wherein the material response depends very strongly on the type, strength, and duration of the external forcing. PMID:25729113

  6. Characterization of cell suspensions from solid tumors

    SciTech Connect

    Pallavicini, M.

    1985-07-10

    The desirable features of cells in suspension will necessarily be dependent upon the use for which the cells were prepared. Adequate cell yield or recovery is defined by the measurement to be performed. Retention of cellular morphology is important for microscopic identification of cell types in a heterogenous cell suspension, and may be used to determine whether the cells in suspension are representative of those in the tumor in situ. Different dispersal protocols may yield cells with different degrees of clonogenicity, as well as altered biochemical features, such as loss of cellular proteins, surface antigens, nucleotide pools, etc. The quality of the cell suspension can be judged by the degree of cell clumping and level of cellular debris, both of which impact on flow cytometric measurements and studies in which the number of cells be known accurately. Finally, if the data measured on the cells in suspension are to be extrapolated to phenomena occurring in the tumor in situ, it is desirable that the cells in suspension are representative of those in the solid tumor in vivo. This report compares characteristics of tumor cell suspensions obtained by different types of selected disaggregation methods. 33 refs., 2 figs., 4 tabs.

  7. Rheology of nanocrystalline cellulose aqueous suspensions.

    PubMed

    Shafiei-Sabet, Sadaf; Hamad, Wadood Y; Hatzikiriakos, Savvas G

    2012-12-11

    The rheological properties and microstructure of nanocrystalline cellulose (NCC) aqueous suspensions have been investigated at different concentrations. The suspension is isotropic up to 3 wt %, and phase separates to liquid crystalline and isotropic domains at higher concentrations where the samples exhibit a fingerprint texture and the viscosity profile shows a three-region behavior, typical of liquid crystals. The suspension behaves as a rheological gel at even higher concentrations where the viscosity profile shows a single shear thinning behavior over the whole range of shear rates investigated. The effects of ultrasound energy and temperature on the rheological properties and structure of these suspensions were studied using polarized optical microscopy and rheometry. Our results indicate that the amount of applied ultrasound energy affects the microstructure of the suspensions and the pitch of the chiral nematic domains. The viscosity profile is changed significantly at low shear rates, whereas the viscosity of biphasic suspensions at intermediate and high shear rates decreased with increasing temperature. This suggests that, between 30 and 40 °C, structural rearrangement takes place. At higher concentrations of about 10 wt %, the temperature has no significant effect on viscosity; however, a marked increase in viscosity has been observed at around 50 °C. Finally, the Cox-Merz rule was found to fail after a critical concentration, thereby implying significant structural formation. This critical concentration is much higher for sonicated compared to unsonicated suspensions.

  8. Restructuring and aging in a capillary suspension.

    PubMed

    Koos, Erin; Kannowade, Wolfgang; Willenbacher, Norbert

    2014-12-01

    The rheological properties of capillary suspensions, suspensions with small amounts of an added immiscible fluid, are dramatically altered with the addition of the secondary fluid. We investigate a capillary suspension to determine how the network ages and restructures at rest and under applied external shear deformation. The present work uses calcium carbonate suspended in silicone oil (11 % solids) with added water as a model system. Aging of capillary suspensions and their response to applied oscillatory shear is distinctly different from particulate gels dominated by the van der Waals forces. The suspensions dominated by the capillary force are very sensitive to oscillatory flow, with the linear viscoelastic regime ending at a deformation of only 0.1% and demonstrating power-law aging behavior. This aging persists for long times at low deformations or for shorter times with a sudden decrease in the strength at higher deformations. This aging behavior suggests that the network is able to rearrange and even rupture. This same sensitivity is not demonstrated in shear flow where very high shear rates are required to rupture the agglomerates returning the apparent viscosity of capillary suspensions to the same viscosity as for the pure vdW suspension. A transitional region is also present at intermediate water contents wherein the material response depends very strongly on the type, strength, and duration of the external forcing.

  9. Stability of extemporaneously prepared rosuvastatin oral suspension.

    PubMed

    Zaid, Abdel Naser; Shtayah, Rania; Qadumi, Ayman; Ghanem, Mashour; Qedan, Rawan; Daibes, Marah; Awwad, Somud Abu; Jaradat, Nidal; Kittana, Naim

    2017-10-01

    The stability of an extemporaneously prepared rosuvastatin suspension stored over 30 days under various storage conditions was evaluated. Rosuvastatin suspension was extemporaneously prepared using commercial rosuvastatin tablets as the source of active pharmaceutical ingredient. The organoleptic properties, dissolution profile, and stability of the formulation were investigated. For the stability studies, samples of the suspension were stored under 2 storage conditions, room temperature (25 °C and 60% relative humidity) and accelerated stability chambers (40 °C and 75% relative humidity). Viscosity, pH, organoleptic properties, and microbial contamination were evaluated according to the approved specifications. High-performance liquid chromatography was used for the analysis and quantification of rosuvastatin in selected samples. Microbiological investigations were also conducted. The prepared suspension showed acceptable organoleptic properties. It showed complete release of rosuvastatin within 15 minutes. The pH of the suspension was 9.8, which remained unchanged during the stability studies. The microbiological investigations demonstrated that the preparation was free of any microbial contamination. In addition, the suspension showed stability within at least the period of use of a 100-mL rosuvastatin bottle. Extemporaneously prepared rosuvastatin 20-mg/mL suspension was stable for 30 days when stored at room temperature. Copyright © 2017 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

  10. Fifth International Symposium on Magnetic Suspension Technology

    NASA Technical Reports Server (NTRS)

    Groom, Nelson J. (Editor); Britcher, Colin P.

    2000-01-01

    In order to examine the state of technology of all areas of magnetic suspension and to review recent developments in sensors, controls, superconducting magnet technology, and design/implementation practices, the Fifth International Symposium on Magnetic Suspension Technology was held at the Radisson Hotel Santa Barbara, Santa Barbara, California, on December 1-3, 1999. The symposium included 18 sessions in which a total of 53 papers were presented. The technical sessions covered the areas of bearings, controls, modeling, electromagnetic launch, magnetic suspension in wind tunnels, applications flywheel energy storage, rotating machinery, vibration isolation, and maglev. A list of attendees is included in the document.

  11. Large angle magnetic suspension test fixture

    NASA Technical Reports Server (NTRS)

    Britcher, Colin P. (Principal Investigator); Huang, Jen-Kuang (Principal Investigator)

    1996-01-01

    Good progress is being made in several major areas. These include eddy current modelling and analysis, design optimization methods, wind tunnel Magnetic Suspension and Balance Systems (MSBS), payload pointing and vibration isolation systems, and system identification. In addition, another successful International Symposium has been completed, with the Proceedings being printed at the time of writing. These activities continue current work under this Grant and extend previous work on magnetic suspension systems and devices in the Guidance and Control Branch and will permit the demonstration of several new developments in the field of magnetic suspension technology.

  12. Fourth International Symposium on Magnetic Suspension Technology

    NASA Technical Reports Server (NTRS)

    Groom, Nelson J. (Editor); Britcher, Colin P. (Editor)

    1998-01-01

    In order to examine the state of technology of all areas of magnetic suspension and to review recent developments in sensors, controls, superconducting magnet technology, and design/implementation practices, the Fourth International Symposium on Magnetic Suspension Technology was held at The Nagaragawa Convention Center in Gifu, Japan, on October 30 - November 1, 1997. The symposium included 13 sessions in which a total of 35 papers were presented. The technical sessions covered the areas of maglev, controls, high critical temperature (T(sub c)) superconductivity, bearings, magnetic suspension and balance systems (MSBS), levitation, modeling, and applications. A list of attendees is included in the document.

  13. Stable suspension for Vi-agglutination tests

    PubMed Central

    Ando, Koji; Shimojo, Hiroto

    1953-01-01

    Two methods of preparing a stable suspension for Vi-agglutination tests are discussed. Both maintain Vi-agglutinability and O-inagglutinability after storage at 37°C for 6 months, and the second also maintains the Vi-capsule-staining property. The first method involves the addition of 0.5% CaCl2 to a heavy saline Vi-suspension, while in the second a similar suspension is treated with an 0.2% solution of chrome alum. PMID:20603972

  14. 48 CFR 42.1302 - Suspension of work.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 1 2014-10-01 2014-10-01 false Suspension of work. 42... MANAGEMENT CONTRACT ADMINISTRATION AND AUDIT SERVICES Suspension of Work, Stop-Work Orders, and Government Delay of Work 42.1302 Suspension of work. A suspension of work under a construction or architect...

  15. Suspension, Race, and Disability: Analysis of Statewide Practices and Reporting

    ERIC Educational Resources Information Center

    Krezmien, Michael P.; Leone, Peter E.; Achilles, Georgianna M.

    2006-01-01

    This analysis of statewide suspension data from 1995 to 2003 in Maryland investigated disproportionate suspensions of minority students and students with disabilities. We found substantial increases in over-all rates of suspensions from 1995 to 2003, as well as disproportionate rates of suspensions for African American students, American Indian…

  16. 48 CFR 42.1302 - Suspension of work.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Suspension of work. 42... MANAGEMENT CONTRACT ADMINISTRATION AND AUDIT SERVICES Suspension of Work, Stop-Work Orders, and Government Delay of Work 42.1302 Suspension of work. A suspension of work under a construction or architect...

  17. 12. UNIDENTIFIED CABLESTAYED SUSPENSION BRIDGE WITH TIMBER RAILING OF TWELVE ...

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

    12. UNIDENTIFIED CABLE-STAYED SUSPENSION BRIDGE WITH TIMBER RAILING OF TWELVE PANELS, SHOWING CABLE PATTERN SIMILAR TO E.E. RUNYON'S SUSPENSION BRIDGE PATENTS. THE BLUFF DALE SUSPENSION BRIDGE'S CABLES MAY HAVE ORIGINALLY FOLLOWED THIS PATTERN. 3/4 VIEW FROM ABOVE. - Bluff Dale Suspension Bridge, Spanning Paluxy River at County Route 149, Bluff Dale, Erath County, TX

  18. 13. UNIDENTIFIED CABLESTAYED SUSPENSION BRIDGE WITH TIMBER RAILING OF TWELVE ...

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

    13. UNIDENTIFIED CABLE-STAYED SUSPENSION BRIDGE WITH TIMBER RAILING OF TWELVE PANELS, SHOWING CABLE PATTERN SIMILAR TO E.E. RUNYON'S SUSPENSION BRIDGE PATENTS. THE BLUFF DALE SUSPENSION BRIDGE'S CABLES MAY HAVE ORIGINALLY FOLLOWED THIS PATTERN. ELEVATION VIEW. - Bluff Dale Suspension Bridge, Spanning Paluxy River at County Route 149, Bluff Dale, Erath County, TX

  19. 13 CFR 120.660 - Suspension or revocation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Suspension or revocation. 120.660... Market Suspension Or Revocation of Participant in Secondary Market § 120.660 Suspension or revocation. (a) Suspension or revocation of Lender, broker, dealer, or Registered Holder for violation of Secondary...

  20. 45 CFR 1641.13 - Causes for suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Causes for suspension. 1641.13 Section 1641.13..., SUSPENSION AND REMOVAL OF RECIPIENT AUDITORS Suspension § 1641.13 Causes for suspension. The debarring... that: (a) A cause for debarment under § 1641.7 may exist; (b) The IPA has been indicted for or...

  1. 12 CFR 367.8 - Causes for suspension.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Causes for suspension. 367.8 Section 367.8... SUSPENSION AND EXCLUSION OF CONTRACTOR AND TERMINATION OF CONTRACTS § 367.8 Causes for suspension. (a... suspension by another federal agency; (2) That a cause for exclusion under § 367.6 may exist; (3) Of the...

  2. 48 CFR 42.1302 - Suspension of work.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Suspension of work. 42... MANAGEMENT CONTRACT ADMINISTRATION AND AUDIT SERVICES Suspension of Work, Stop-Work Orders, and Government Delay of Work 42.1302 Suspension of work. A suspension of work under a construction or...

  3. 36 CFR 25.3 - Supervision; suspensions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... service will operate under the direction of the superintendent or his designated representative. Records... the interests of the Government. A full report of the facts attending each suspension will be made...

  4. Optical analysis of red blood cell suspension

    NASA Astrophysics Data System (ADS)

    Szołna, Alicja A.; Grzegorzewski, Bronisław

    2008-12-01

    The optical properties of suspensions of red blood cells (RBCs) were studied. Fresh human venues blood was obtained from adult healthy donors. RBCs were suspended in isotonic salt solution, and in autologous plasma. Suspensions with haematocrit 0.25 - 3% were investigated. Novel technique was proposed to determine the scattering coefficient μs for the suspensions. The intensity of He-Ne laser light transmitted through a wedge-shape container filled with a suspension was recorded. To find the dependence of the intensity on the thickness of the sample the container was moved horizontally. The dependence of μs on the haematocrit was determined for RBCs suspended in the isotonic salt solution. RBCs suspended in plasma tend to form rouleaux. For the RBCs suspended in plasma, the scattering coefficient as a function of time was obtained. It is shown that this technique can be useful in the study of rouleaux formation.

  5. Torsional suspension system for testing space structures

    NASA Technical Reports Server (NTRS)

    Reed, Wilmer H., III (Inventor); Gold, Ronald R. (Inventor)

    1991-01-01

    A low frequency torsional suspension system for testing a space structure uses a plurality of suspension stations attached to the space structure along the length thereof in order to suspend the space structure from an overhead support. Each suspension station includes a disk pivotally mounted to the overhead support, and two cables which have upper ends connected to the disk and lower ends connected to the space structure. The two cables define a parallelogram with the center of gravity of the space structure being vertically beneath the pivot axis of the disk. The vertical distance between the points of attachment of the cables to the disk and the pivot axis of the disk is adjusted to lower the frequency of the suspension system to a level which does not interfere with frequency levels of the space structure, thereby enabling accurate measurement.

  6. A Course in Fluid Mechanics of Suspensions.

    ERIC Educational Resources Information Center

    Davis, Robert H.

    1989-01-01

    Discusses a course focusing on fluid mechanics and physical chemistry of suspensions. Describes the main themes of the lectures and includes a list of course outlines. Possible textbooks and many journal articles are listed. (YP)

  7. Colloidal suspension simulates linear dynamic pressure profile

    NASA Technical Reports Server (NTRS)

    Mc Cann, R. J.

    1966-01-01

    Missile nose fairings immersed in colloidal suspension prepared with various specific gravities simulate pressure profiles very similar to those encountered during reentry. Stress and deflection conditions similar to those expected during atmospheric reentry are thus attained in the laboratory.

  8. Magnetic suspension and balance systems (MSBSs)

    NASA Technical Reports Server (NTRS)

    Britcher, Colin P.; Kilgore, Robert A.

    1987-01-01

    The problems of wind tunnel testing are outlined, with attention given to the problems caused by mechanical support systems, such as support interference, dynamic-testing restrictions, and low productivity. The basic principles of magnetic suspension are highlighted, along with the history of magnetic suspension and balance systems. Roll control, size limitations, high angle of attack, reliability, position sensing, and calibration are discussed among the problems and limitations of the existing magnetic suspension and balance systems. Examples of the existing systems are presented, and design studies for future systems are outlined. Problems specific to large-scale magnetic suspension and balance systems, such as high model loads, requirements for high-power electromagnets, high-capacity power supplies, highly sophisticated control systems and position sensors, and high costs are assessed.

  9. Installation of Curiosity Wheels and Suspension

    NASA Image and Video Library

    2010-07-05

    With the wheels and suspension system already installed onto one side of NASA Mars rover Curiosity the previous day, spacecraft engineers and technicians prepare the other side mobility subsystem for installation on June 29, 2010.

  10. A Course in Fluid Mechanics of Suspensions.

    ERIC Educational Resources Information Center

    Davis, Robert H.

    1989-01-01

    Discusses a course focusing on fluid mechanics and physical chemistry of suspensions. Describes the main themes of the lectures and includes a list of course outlines. Possible textbooks and many journal articles are listed. (YP)

  11. 21 CFR 26.16 - Suspension.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... PHARMACEUTICAL GOOD MANUFACTURING PRACTICE REPORTS, MEDICAL DEVICE QUALITY SYSTEM AUDIT REPORTS, AND CERTAIN... Provisions for Pharmaceutical Good Manufacturing Practices § 26.16 Suspension. (a) Each party has the right...

  12. 21 CFR 26.16 - Suspension.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... PHARMACEUTICAL GOOD MANUFACTURING PRACTICE REPORTS, MEDICAL DEVICE QUALITY SYSTEM AUDIT REPORTS, AND CERTAIN... Provisions for Pharmaceutical Good Manufacturing Practices § 26.16 Suspension. (a) Each party has the right...

  13. 21 CFR 26.16 - Suspension.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... PHARMACEUTICAL GOOD MANUFACTURING PRACTICE REPORTS, MEDICAL DEVICE QUALITY SYSTEM AUDIT REPORTS, AND CERTAIN... Provisions for Pharmaceutical Good Manufacturing Practices § 26.16 Suspension. (a) Each party has the right...

  14. 21 CFR 26.16 - Suspension.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... PHARMACEUTICAL GOOD MANUFACTURING PRACTICE REPORTS, MEDICAL DEVICE QUALITY SYSTEM AUDIT REPORTS, AND CERTAIN... Provisions for Pharmaceutical Good Manufacturing Practices § 26.16 Suspension. (a) Each party has the right...

  15. Large angle magnetic suspension test fixture

    NASA Technical Reports Server (NTRS)

    Britcher, Colin P.

    1993-01-01

    Progress made under the subject grant in the period from 1 Nov. 1992 to 31 May 1993 is presented. The research involves the continued development of the Large Angle Magnetic Suspension Test Fixture (LAMSTF) and also the recommissioning of an additional piece of exisiting hardware. During the period in question, the initial configuration of LAMSTF was completed and made routinely and reliably operational. A digital phase advance controller was completed and documented. The goal of a controlled 360 deg rotation was achieved. Work started on the recommissioning of the Annular Suspension and Pointing System (ASPS). Work completed during the report period included: modeling; position sensing; controller; support of the Second International Symposium on Magnetic Suspension Technology; and recommissioning of the Annular Suspension and Pointing System.

  16. Tunable shear thickening in suspensions

    PubMed Central

    Lin, Neil Y.C.; Ness, Christopher; Cates, Michael E.; Sun, Jin; Cohen, Itai

    2016-01-01

    Shear thickening, an increase of viscosity with shear rate, is a ubiquitous phenomenon in suspended materials that has implications for broad technological applications. Controlling this thickening behavior remains a major challenge and has led to empirical strategies ranging from altering the particle surfaces and shape to modifying the solvent properties. However, none of these methods allows for tuning of flow properties during shear itself. Here, we demonstrate that by strategic imposition of a high-frequency and low-amplitude shear perturbation orthogonal to the primary shearing flow, we can largely eradicate shear thickening. The orthogonal shear effectively becomes a regulator for controlling thickening in the suspension, allowing the viscosity to be reduced by up to 2 decades on demand. In a separate setup, we show that such effects can be induced by simply agitating the sample transversely to the primary shear direction. Overall, the ability of in situ manipulation of shear thickening paves a route toward creating materials whose mechanical properties can be controlled. PMID:27621472

  17. Teloscopy after bladder neck suspension.

    PubMed

    Shoemaker, E S; Wilkinson, P D

    1998-08-01

    Teloscopy, a method of suprapubic cystoscopy, involves placing a telescope into the dome of a full bladder to examine the bladder interior. A 5-mm Dexide cannula was pierced through the dome of the bladder and a telescope was inserted through it. This specialized cannula sleeve maintained bladder distention and allowed an excellent wide-angle view of the interior of the bladder and ureteral orifices. In a retrospective analysis, 103 consecutive women with stress urinary incontinence who underwent retropubic urethropexy were placed into one of three categories: Burch laparotomy (13), Burch laparoscopy (44), or laparoscopy with mesh and staples (46). Teloscopy was performed and indigo carmine was given intravenously at the end of the procedure in 90 patients. Of these, seven (8%) were positive. In all seven a suture was seen through the bladder mucosa, and in five an additional obstructed ureter was observed. In all seven women the suture was removed and replaced, and all obstructed ureters were patent before the end of the procedure. Average time required was 4 minutes. No complications, short- or long-term, occurred in the 90 women. Our results support the view that cystoscopy should be performed at the end of bladder neck suspension.

  18. 48 CFR 3023.506 - Suspension of payments, termination of contract, and debarment and suspension actions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...) SOCIOECONOMIC PROGRAMS ENVIRONMENT, ENERGY AND WATER EFFICIENCY, RENEWABLE ENERGY TECHNOLOGIES, OCCUPATIONAL SAFETY, AND DRUG-FREE WORKPLACE Drug-Free Workplace 3023.506 Suspension of payments, termination...

  19. 48 CFR 3023.506 - Suspension of payments, termination of contract, and debarment and suspension actions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...) SOCIOECONOMIC PROGRAMS ENVIRONMENT, ENERGY AND WATER EFFICIENCY, RENEWABLE ENERGY TECHNOLOGIES, OCCUPATIONAL SAFETY, AND DRUG-FREE WORKPLACE Drug-Free Workplace 3023.506 Suspension of payments, termination...

  20. 48 CFR 3023.506 - Suspension of payments, termination of contract, and debarment and suspension actions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...) SOCIOECONOMIC PROGRAMS ENVIRONMENT, ENERGY AND WATER EFFICIENCY, RENEWABLE ENERGY TECHNOLOGIES, OCCUPATIONAL SAFETY, AND DRUG-FREE WORKPLACE Drug-Free Workplace 3023.506 Suspension of payments, termination...

  1. Mass Transfer and Rheology of Fiber Suspensions

    NASA Astrophysics Data System (ADS)

    Wang, Jianghui

    Rheological and mass transfer properties of non-Brownian fiber suspensions are affected by fiber characteristics, fiber interactions, and processing conditions. In this thesis we develop several simulation methods to study the dynamics of single fibers in simple shear flow, as well as the rheology and mass transfer of fiber suspensions. Isolated, rigid, neutrally-buoyant, non-Brownian, slightly curved, nonchiral fibers in simple shear flow of an incompressible Newtonian fluid at low Reynolds number can drift steadily in the gradient direction without external forces or torques. The average drift velocity and direction depend on the fiber aspect ratio, curvature and initial orientation. The drift results from the coupling of rotational and translational dynamics, and the combined effects of flipping, scooping, and spinning motions of the fiber. Irreversible fiber collisions in the suspensions cause shear-induced diffusion. The shear-induced self-diffusivity of dilute suspensions of fibers increases with increasing concentration and increasing static friction between contacts. The diffusivities in both the gradient and vorticity directions are larger for suspensions of curved fibers than for suspensions of straight fibers. For suspensions of curved fibers, significant enhancements in the diffusivity in the gradient direction are attributed to fiber drift in the gradient direction. The shear-induced self-diffusivity of concentrated suspensions of fibers increases with increasing concentration before fiber networks or flocs are formed, after which the diffusivity decreases with increasing concentration. The diffusivity increases with increasing fiber equilibrium bending angle, effective stiffness, coefficient of static friction, and rate of collisions. The specific viscosity of fiber suspensions increases with increasing fiber curvature, friction coefficient between mechanical contacts, and solids concentration. The specific viscosity increases linearly with

  2. Simulating Fibre Suspensions: Lagrangian versus Statistical Approach

    NASA Astrophysics Data System (ADS)

    Zhao, L. H.; Andersson, H. I.; Gillissen, J. J. J.; Boersma, B. J.

    Fibre suspensions exhibit complex dynamical flow phenomena and are at the same time of immense practical importance, notably in the pulp and paper industries. NTNU and TU Delft have in a collaborative research project adopted two alternative strategies in the simulation of dilute fibre suspensions, namely a statistical approach [2] and a Lagrangian particle treatment [4]. The two approaches have their own advantages and disadvantages. In this paper we aim for the first time to compare the performance of the two.

  3. Fluidic Technology Investigation - Suspension Damping Simulations

    DTIC Science & Technology

    1977-01-01

    IF (w (I LT’ CVM)~4$1 IF ( Wrf 1 0 i CmpY MX2)V?1112wW~ CALL ORPArIP:(Pcx) pP,i.,IERR) .......-or pi i v~,R4p CAlLA (QAI)Rr7,4,?,T.ERR) T F Z (I ~LT C V...Damper Damping Devices Suspension Systems Shock Absorbers Adaptive Suspension Systems Hydro -Fluidics 20. ABSTRACT (Continue on reverse side if necessary

  4. X-ray Mapping of Dynamic Suspensions

    NASA Astrophysics Data System (ADS)

    Gholami, Mohammad; Lenoir, Nicolas; Ovarlez, Guillaume; Hormozi, Sarah

    2016-11-01

    Dense non-colloidal suspensions are materials with broad application both in industrial processes and natural phenomena. In most of these applications, the suspensions are either far from equilibrium or strongly non-Newtonian (i.e., non-colloidal particles are suspended in non-Newtonian fluid) meaning that the flow kinetics are not only strain-dependent but also strain-rate dependent. Therefore, experimental techniques must be developed to analyze the flows of these complex suspensions over a wide range of steady and transient shear rates. Techniques such as Nuclear Magnetic Resonance/Imaging (NMR/I) are inapplicable due to low sampling frequency and low image resolution (typically 10 minutes per averaged NMR image of 1x1cm). We introduce a new technique using an X-ray/CT-scan system to study dynamic suspensions. We show our recent results on the application of this technique for the study of shear induced migration of particles in a yield stress matrix fluid in a wide-gap cylindrical Couette cell. This work opens new avenues to study dynamic non-colloidal suspensions and the suspensions with other types of nonlinear suspending fluids such as viscoelastic and shear thickening fluids. NFS(CBET-1554044-CAREER).

  5. Bubbly Suspension Generated in Low Gravity

    NASA Technical Reports Server (NTRS)

    Nahra, Henry K.

    2000-01-01

    Bubbly suspensions are crucial for mass and heat transport processes on Earth and in space. These processes are relevant to pharmaceutical, chemical, nuclear, and petroleum industries on Earth. They are also relevant to life support, in situ resource utilization, and propulsion processes for long-duration space missions such as the Human Exploration and Development of Space program. Understanding the behavior of the suspension in low gravity is crucial because of factors such as bubble segregation, which could result in coalescence and affect heat and mass transport. Professors A. Sangani and D. Koch, principal investigators in the Microgravity Fluid Physics Program managed by the NASA Glenn Research Center at Lewis Field, are studying the physics of bubbly suspension. They plan to shear a bubbly suspension in a couette cell in microgravity to study bubble segregation and compare the bubble distribution in the couette gap with the one predicted by the suspension-averaged equations of motion. Prior to the Requirement Definition Review of this flight experiment, a technology for generating a bubbly suspension in microgravity has to be established, tested, and verified.

  6. Dewatering of flocculated suspensions by pressure filtration

    NASA Astrophysics Data System (ADS)

    Landman, K. A.; Sirakoff, C.; White, L. R.

    1991-06-01

    Pressure filtration is an important method for removing liquids from a suspension. Previous work used linear models or applied to stable suspensions. Nonlinear models for flocculated suspensions are studied here. The equations governing the consolidation of flocculated suspensions under the influence of an applied pressure are based on the assumption that when the volume fraction is high enough, the network formed from the aggregation of flocs possesses a compressive yield stress Py(φ) that is a function of local volume fraction φ only. There are two modes of operation of the pressure filter—the fluid flux or the applied pressure is specified—and both of these are studied. The resulting nonlinear partial differential equations involve the time-dependent piston position, and in the case of the suspension being initially unnetworked, another internal moving boundary below which the suspension is networked. The small time behavior of these systems is obtained with an asymptotic method. In general, at later times, the solution can only be found numerically and an algorithm for doing this is discussed. The important parameters and properties of the filter cake are described. The results suggest various ways of controlling the filtration process, which may be useful in the manufacture of ceramics.

  7. Dissipative Particle Dynamics simulation of colloidal suspensions

    NASA Astrophysics Data System (ADS)

    Jamali, Safa; Boromand, Arman; Maia, Joao

    2014-03-01

    DPD as a mesoscale method was firstly proposed to study dynamics of suspensions under flow condition. However the proposed method failed to capture shear properties of suspensions because it lacked: first a potential to reproduce lubrication forces and second a clear definition for the colloid surface. Recently we reported a modified DPD method which defines colloidal particles as particles with hard core and a dissipative coat. An additional lubrication force was introduced to include the short-range hydrodynamics that are not captured in original DPD. The model was found to be able to reproduce shear properties of suspensions for a wide range of different systems, from monodisperse to bimodal with different volume fractions, compositions and size ratios. In present work our modified DPD method is employed to study both equilibrium and flow properties of colloidal suspension. Zero shear viscosity of suspension is measured using Green-Kubo expressions and the results are compared to theoretical predictions. Furthermore, structure formation in suspensions is studied in respect to energy landscape of the fluid both at rest and under flow.

  8. Interleukin-2 therapy reverses some immunosuppressive effects of skeletal unloading

    NASA Technical Reports Server (NTRS)

    Armstrong, Jason W.; Balch, Signe; Chapes, Stephen K.

    1994-01-01

    Using antiorthostatic suspension, we characterized hematopoietic changes that may be responsible for the detrimental effect of skeletal unloading on macrophage development. Skeletally unloaded mice had suppressed macrophage development in unloaded and loaded bones, which indicated a systemic effect. Bone marrow cells from unloaded mice secreted less macrophage colony-stimulating factor and interleukin-6 than control mice. Additionally, T-lymphocyte proliferation was reduced after skeletal unloading. We show that polyethylene glycol-interleukin-2 therapy reversed the effects of skeletal unloading on macrophage development and cell proliferation.

  9. Interleukin-2 therapy reverses some immunosuppressive effects of skeletal unloading

    NASA Technical Reports Server (NTRS)

    Armstrong, Jason W.; Balch, Signe; Chapes, Stephen K.

    1994-01-01

    Using antiorthostatic suspension, we characterized hematopoietic changes that may be responsible for the detrimental effect of skeletal unloading on macrophage development. Skeletally unloaded mice had suppressed macrophage development in unloaded and loaded bones, which indicated a systemic effect. Bone marrow cells from unloaded mice secreted less macrophage colony-stimulating factor and interleukin-6 than control mice. Additionally, T-lymphocyte proliferation was reduced after skeletal unloading. We show that polyethylene glycol-interleukin-2 therapy reversed the effects of skeletal unloading on macrophage development and cell proliferation.

  10. Inertial Effects in Suspension Dynamics

    NASA Technical Reports Server (NTRS)

    J. F. Brady; Subramanian, G.

    2000-01-01

    The present work analyses the dynamics of a suspension of heavy particles in shear flow. The magnitude of the particle inertia is given by the Stokes number St = m(gamma/6(pi)a, which is the ratio of the viscous relaxation time of a particle tau(sub p) = m=6pi(eta)a to the flow time gamma(sup -1). Here, m is the mass of the particle, a is its size, eta is the viscosity of the suspending fluid and gamma is the shear rate. The ratio of the Stokes number to the Reynolds number, Re = (rho)f(gamma)a(exp 2)/eta, is the density ratio rho(sub p)/rho(sub f). Of interest is to understand the separate roles of particle (St) and fluid (Re) inertia in the dynamics of suspensions. In this study we focus on heavy particles, rho(sub p)/rho(sub f) much greater than 1, for which the Stokes number is finite, but the Reynolds number is sufficiently small for inertial forces in the fluid to be neglected; thus, the fluid motion is governed by the Stokes equations. On the other hand, the probability density governing the statistics of the suspended particles satisfies a Fokker-Planck equation that accounts for both configuration and momentum coordinates, the latter being essential for finite St. The solution of the Fokker-Planck equation is obtained to O(St) via a Chapman-Enskog type-procedure, and the conditional velocity distribution so obtained is used to derive a configuration-space Smoluchowski equation with inertial corrections. The inertial effects are responsible for asymmetry in the relative trajectories of two spheres in shear flow, in contrast to the well known symmetric structure in the absence of inertia. Finite St open trajectories in the plane of shear suffer a downward lateral displacement resulting from the inability of a particle of finite mass to follow the curvature of the zero-Stokes-number pathlines. In addition to the induced asymmetry, the O(St) inertial perturbation dramatically alters the nature of the near-field trajectories. The stable closed orbits (for St

  11. Stability of Propranolol in Extemporaneously Compounded Suspensions

    PubMed Central

    Ensom, Mary H H; Kendrick, Jennifer; Rudolph, Susan; Decarie, Diane

    2013-01-01

    Background: Propranolol is a drug of choice for many diseases occurring in neonates and infants, an age group for which oral suspensions are required almost exclusively. Many adult and elderly patients for whom propranolol is prescribed are also unable to swallow solid dosage forms. In Canada, propranolol is not commercially available in a liquid dosage form, and existing recipes for extemporaneously compounded suspensions of propranolol (1 mg/mL) are limited by concerns regarding diabetes mellitus in certain subpopulations, the need for a more concentrated suspension for patients taking larger doses, and the tediousness of compounding. Objective: To evaluate the stability of propranolol suspensions in a sugar-free, commercially available vehicle after storage at room temperature and under refrigeration for up to 120 days. Methods: Suspensions of propranolol (2 and 5 mg/mL) were prepared in the sugar-free vehicle (Ora-Blend SF), placed in 100-mL amber plastic prescription bottles, and stored at 25°C and 4°C. Samples were collected from each bottle once weekly for 120 days, stored frozen, and analyzed by a validated, stability-indicating high-performance liquid chromatography – ultraviolet detection method. A suspension was considered stable if it maintained at least 90% of its initial concentration of propranolol. Physical compatibility was evaluated in terms of colour, taste, precipitation, and pH. Results: Propranolol suspensions 2 mg/mL and 5 mg/mL stored at 25°C maintained at least 94.7% of their initial concentration for 120 days, and suspensions stored at 4°C maintained at least 93.9% of their initial concentration for 120 days. There were no notable changes in pH, and all samples remained physically unchanged except for a slight change in colour, around day 70, of suspensions stored at room temperature. Conclusion: Propranolol suspensions (2 mg/mL and 5 mg/mL) prepared in Ora-Blend SF and stored in plastic prescription bottles at either 25°C or 4

  12. Stability of propranolol in extemporaneously compounded suspensions.

    PubMed

    Ensom, Mary H H; Kendrick, Jennifer; Rudolph, Susan; Decarie, Diane

    2013-03-01

    Propranolol is a drug of choice for many diseases occurring in neonates and infants, an age group for which oral suspensions are required almost exclusively. Many adult and elderly patients for whom propranolol is prescribed are also unable to swallow solid dosage forms. In Canada, propranolol is not commercially available in a liquid dosage form, and existing recipes for extemporaneously compounded suspensions of propranolol (1 mg/mL) are limited by concerns regarding diabetes mellitus in certain subpopulations, the need for a more concentrated suspension for patients taking larger doses, and the tediousness of compounding. To evaluate the stability of propranolol suspensions in a sugar-free, commercially available vehicle after storage at room temperature and under refrigeration for up to 120 days. Suspensions of propranolol (2 and 5 mg/mL) were prepared in the sugar-free vehicle (Ora-Blend SF), placed in 100-mL amber plastic prescription bottles, and stored at 25°C and 4°C. Samples were collected from each bottle once weekly for 120 days, stored frozen, and analyzed by a validated, stability-indicating high-performance liquid chromatography - ultraviolet detection method. A suspension was considered stable if it maintained at least 90% of its initial concentration of propranolol. Physical compatibility was evaluated in terms of colour, taste, precipitation, and pH. Propranolol suspensions 2 mg/mL and 5 mg/mL stored at 25°C maintained at least 94.7% of their initial concentration for 120 days, and suspensions stored at 4°C maintained at least 93.9% of their initial concentration for 120 days. There were no notable changes in pH, and all samples remained physically unchanged except for a slight change in colour, around day 70, of suspensions stored at room temperature. Propranolol suspensions (2 mg/mL and 5 mg/mL) prepared in Ora-Blend SF and stored in plastic prescription bottles at either 25°C or 4°C are expected to remain stable for 120 days.

  13. 20 CFR 416.1599 - Reinstatement after suspension or disqualification-period of suspension not expired.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Reinstatement after suspension or disqualification-period of suspension not expired. 416.1599 Section 416.1599 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Representation of Parties §...

  14. 20 CFR 404.1799 - Reinstatement after suspension or disqualification-period of suspension not expired.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Reinstatement after suspension or disqualification-period of suspension not expired. 404.1799 Section 404.1799 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) Representation of Parties §...

  15. 20 CFR 416.1597 - Reinstatement after suspension-period of suspension expired.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Reinstatement after suspension-period of suspension expired. 416.1597 Section 416.1597 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SUPPLEMENTAL SECURITY INCOME FOR THE AGED, BLIND, AND DISABLED Representation of Parties § 416.1597 Reinstatement...

  16. 20 CFR 404.1797 - Reinstatement after suspension-period of suspension expired.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 2 2010-04-01 2010-04-01 false Reinstatement after suspension-period of suspension expired. 404.1797 Section 404.1797 Employees' Benefits SOCIAL SECURITY ADMINISTRATION FEDERAL OLD-AGE, SURVIVORS AND DISABILITY INSURANCE (1950- ) Representation of Parties § 404.1797...

  17. 46 CFR 565.10 - Suspension procedures, period of suspension, and replacement rates.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... greater than 180 days. (c) Implementation. (1) Upon issuance of an order suspending a rate, charge... replacement rates. 565.10 Section 565.10 Shipping FEDERAL MARITIME COMMISSION REGULATIONS AND ACTIONS TO... of suspension, and replacement rates. (a)(1) Suspension prior to effective date. Pending a...

  18. Rheological behavior of oxide nanopowder suspensions

    NASA Astrophysics Data System (ADS)

    Cinar, Simge

    Ceramic nanopowders offer great potential in advanced ceramic materials and many other technologically important applications. Because a material's rheological properties are crucial for most processing routes, control of the rheological behavior has drawn significant attention in the recent past. The control of rheological behavior relies on an understanding of how different parameters affect the suspension viscosities. Even though the suspension stabilization mechanisms are relatively well understood for sub-micron and micron size particle systems, this knowledge cannot be directly transferred to nanopowder suspensions. Nanopowder suspensions exhibit unexpectedly high viscosities that cannot be explained with conventional mechanisms and are still a topic of investigation. This dissertation aims to establish the critical parameters governing the rheological behavior of concentrated oxide nanopowder suspensions, and to elucidate the mechanisms by which these parameters control the rheology of these suspensions. Aqueous alumina nanopowders were chosen as a model system, and the findings were extrapolated to other oxide nanopowder systems such as zirconia, yttria stabilized zirconia, and titania. Processing additives such as fructose, NaCl, HCl, NaOH, and ascorbic acid were used in this study. The effect of solids content and addition of fructose on the viscosity of alumina nanopowder suspensions was investigated by low temperature differential scanning calorimetry (LT-DSC), rheological, and zeta potential measurements. The analysis of bound water events observed in LT-DSC revealed useful information regarding the rheological behavior of nanopowder suspensions. Because of the significance of interparticle interactions in nanopowder suspensions, the electrostatic stabilization was investigated using indifferent and potential determining ions. Different mechanisms, e.g., the effect of the change in effective volume fraction caused by fructose addition and electrostatic

  19. Effective viscosity of dilute bacterial suspensions

    NASA Astrophysics Data System (ADS)

    Haines, Brian M.

    This dissertation explores the bulk (volume averaged) properties of suspensions of microswimmers in a fluid. A microswimmer is a microscopic object that propels itself through a fluid. A common example of a microswimmer is a bacterium, such as Bacillus subtilis. Our particular interest is the bulk rheological properties of suspensions of bacteria -- that is, studying how such a suspension deforms under the application of an external force. In the simplest case, the rheology of a fluid can be described by a scalar effective viscosity. The goal of this dissertation is to find explicit formulae for the effective viscosity in terms of known geometric and physical parameters characterizing bacteria and use them to explain experimental observations. Throughout the dissertation, we consider bacterial suspensions in the dilute limit, where bacteria are assumed to be so far apart that interactions between them are negligible. This simplifies calculations significantly and is the regime in which the most striking experimental results have been observed. We first study suspensions of self-propelled particles using a two-dimensional (2D) Partial Differential Equation (PDE) model. A bacterium is modeled as a disk in 2D with self-propulsion provided by a point force in the fluid. A formula is obtained for the effective viscosity of such suspensions in the dilute limit. This formula includes the two terms that are found in the 2D version of Einstein's classical result for a passive suspension of spheres. To this, our main contribution is added, an additional term due to self-propulsion which depends on the physical and geometric properties of the suspension. This work demonstrates how bacterial self-propulsion can alter the viscosity of a fluid and highlights the importance of bacterial orientation. Next, we present a more realistic PDE model for dilute suspensions of swimming bacteria in a three-dimensional fluid. In this work, a bacterium is modeled as a prolate spheroid with

  20. A review of dynamics modelling of friction wedge suspensions

    NASA Astrophysics Data System (ADS)

    Wu, Qing; Cole, Colin; Spiryagin, Maksym; Sun, Yan Quan

    2014-11-01

    Three-piece bogies with friction wedge suspensions are the most widely used bogies in heavy haul trains. Fiction wedge suspensions play a key role in these wagon systems. This article reviews current techniques in dynamic modelling of friction wedge suspension with various motivations: to improve dynamic models of friction wedge suspensions so as to improve general wagon dynamics simulations; to seek better friction wedge suspension models for wagon stability assessments in complex train systems; to improve the modelling of other friction devices, such as friction draft gear. Relevant theories and friction wedge suspension models developed by using commercial simulation packages and in-house simulation packages are reviewed.

  1. Flux-Feedback Magnetic-Suspension Actuator

    NASA Technical Reports Server (NTRS)

    Groom, Nelson J.

    1990-01-01

    Flux-feedback magnetic-suspension actuator provides magnetic suspension and control forces having linear transfer characteristics between force command and force output over large range of gaps. Hall-effect devices used as sensors for electronic feedback circuit controlling currents flowing in electromagnetic windings to maintain flux linking suspended element at substantially constant value independent of changes in length of gap. Technique provides effective method for maintenance of constant flux density in gap and simpler than previous methods. Applications include magnetic actuators for control of shapes and figures of antennas and of precise segmented reflectors, magnetic suspensions in devices for storage of angular momentum and/or kinetic energy, and systems for control, pointing, and isolation of instruments.

  2. Stability of dynamic response of suspension bridges

    NASA Astrophysics Data System (ADS)

    Capsoni, Antonio; Ardito, Raffaele; Guerrieri, Andrea

    2017-04-01

    The potential occurrence of internal parametric resonance phenomena has been recently indicated as a potential contributory cause of the appearance of critical dynamic states in long-span suspension bridges. At the same time, suspension bridges, in view of their flexibility, are prone to aeroelastic response, such as vortex shedding, torsional divergence and flutter. In this paper, a non-linear dynamic model of a suspension bridge is devised, with the purpose of providing a first attempt toward a unified framework for the study of aeroelastic and internal resonance instabilities. Inspired by the pioneering work of Herrmann and Hauger, the analyses have been based on a linearized formulation that is able to represent the main structural non-linear effects and the coupling given by aerodynamic forces. The results confirm that the interaction between aeroelastic effects and non-linear internal resonance leads to unstable conditions for wind speeds which can be lower than the critical threshold for standard aeroelastic predictions.

  3. Graphene suspensions for 2D printing

    NASA Astrophysics Data System (ADS)

    Soots, R. A.; Yakimchuk, E. A.; Nebogatikova, N. A.; Kotin, I. A.; Antonova, I. V.

    2016-04-01

    It is shown that, by processing a graphite suspension in ethanol or water by ultrasound and centrifuging, it is possible to obtain particles with thicknesses within 1-6 nm and, in the most interesting cases, 1-1.5 nm. Analogous treatment of a graphite suspension in organic solvent yields eventually thicker particles (up to 6-10 nm thick) even upon long-term treatment. Using the proposed ink based on graphene and aqueous ethanol with ethylcellulose and terpineol additives for 2D printing, thin (~5 nm thick) films with sheet resistance upon annealing ~30 MΩ/□ were obtained. With the ink based on aqueous graphene suspension, the sheet resistance was ~5-12 kΩ/□ for 6- to 15-nm-thick layers with a carrier mobility of ~30-50 cm2/(V s).

  4. Vibration-induced liquefaction of granular suspensions.

    PubMed

    Hanotin, C; Kiesgen de Richter, S; Marchal, P; Michot, L J; Baravian, C

    2012-05-11

    We investigate the mechanical behavior of granular suspensions subjected to coupled vibrations and shear. At high shear stress, whatever the mechanical vibration energy and bead size, the system behaves like a homogeneous suspension of hard spheres. At low shear stress, in addition to a dependence on bead size, vibration energy drastically influences the viscosity of the material that can decrease by more than 2 orders of magnitude. All experiments can be rationalized by introducing a hydrodynamical Peclet number defined as the ratio between the lubrication stress induced by vibrations and granular pressure. The behavior of vibrated wet and dry granular materials can then be unified by assimilating the hookean stress in dry media to the lubrication stress in suspensions.

  5. Dielectric spectroscopy of bidisperse colloidal suspensions.

    PubMed

    Beltramo, Peter J; Furst, Eric M

    2012-08-15

    Dielectric spectroscopy is used to measure the complex permittivity of bidisperse colloidal suspensions over the frequency range 2.5 kHz ≤ ω/2π ≤ 10 MHz using the spectrometer design of Hollingsworth and Saville (A.D. Hollingsworth, D.A. Saville, J. Colloid Interface Sci., 2003). Dielectric spectra of monodisperse polystyrene spheres of two diameters (530 nm and 1 μm) are fit to electrokinetic theory using the surface charge density as an adjustable parameter. Quantitative agreement is found in the dielectric increment and also for the conductivity increment, after considering the effect of added counterions and nonspecific adsorption. Bidisperse suspension spectra are a linear superposition of each particle's dielectric response. The results provide a simple method to extend standard electrokinetic theory based on a single particle size to dilute suspensions with many particle sizes and verify the sensitivity of the spectrometer. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Anomalous electrical conductivity of nanoscale colloidal suspensions.

    PubMed

    Chakraborty, Suman; Padhy, Sourav

    2008-10-28

    The electrical conductivity of colloidal suspensions containing nanoscale conducting particles is nontrivially related to the particle volume fraction and the electrical double layer thickness. Classical electrochemical models, however, tend to grossly overpredict the pertinent effective electrical conductivity values, as compared to those obtained under experimental conditions. We attempt to address this discrepancy by appealing to the complex interconnection between the aggregation kinetics of the nanoscale particles and the electrodynamics within the double layer. In particular, we model the consequent alterations in the effective electrophoretic mobility values of the suspension by addressing the fundamentals of agglomeration-deagglomeration mechanisms through the pertinent variations in the effective particulate dimensions, solid fractions, as well as the equivalent suspension viscosity. The consequent alterations in the electrical conductivity values provide a substantially improved prediction of the corresponding experimental findings and explain the apparent anomalous behavior predicted by the classical theoretical postulates.

  7. Generation of Bubbly Suspensions in Low Gravity

    NASA Technical Reports Server (NTRS)

    Nahra, Henry K.; Hoffmann, Monica I.; Hussey, Sam; Bell, Kimberly R.

    2000-01-01

    Generation of a uniform monodisperse bubbly suspension in low gravity is a rather difficult task because bubbles do not detach as easily as on Earth. Under microgravity, the buoyancy force is not present to detach the bubbles as they are formed from the nozzles. One way to detach the bubbles is to establish a detaching force that helps their detachment from the orifice. The drag force, established by flowing a liquid in a cross or co-flow configuration with respect to the nozzle direction, provides this additional force and helps detach the bubbles as they are being formed. This paper is concerned with studying the generation of a bubbly suspension in low gravity in support of a flight definition experiment titled "Behavior of Rapidly Sheared Bubbly Suspension." Generation of a bubbly suspension, composed of 2 and 3 mm diameter bubbles with a standard deviation <10% of the bubble diameter, was identified as one of the most important engineering/science issues associated with the flight definition experiment. This paper summarizes the low gravity experiments that were conducted to explore various ways of making the suspension. Two approaches were investigated. The first was to generate the suspension via a chemical reaction between the continuous and dispersed phases using effervescent material, whereas the second considered the direct injection of air into the continuous phase. The results showed that the reaction method did not produce the desired bubble size distribution compared to the direct injection of bubbles. However, direct injection of air into the continuous phase (aqueous salt solution) resulted in uniform bubble-diameter distribution with acceptable bubble-diameter standard deviation.

  8. Vagus Nerve Stimulation

    MedlinePlus

    Vagus nerve stimulation Overview By Mayo Clinic Staff Vagus nerve stimulation is a procedure that involves implantation of a device that stimulates the vagus nerve with electrical impulses. There's one vagus nerve on ...

  9. Deflocculation of clay suspensions using sodium polyacrylates

    NASA Technical Reports Server (NTRS)

    Jedlicka, P.

    1984-01-01

    Rheological properties of elutriated kaolin suspensions deflocculated by Na polyacrylate (DAC 3 and DAC 4) were studied and compared to those deflocculated by the conventional Na2CO3 water and glass and imported Dispex N40. The deflocculating effect of Na polyacrylate was comparable to that of Dispex N40. The optimum amounts of Na polyacrylate were determined for suspensions based on 5-type kaolin. The Na polyacrylate can be successfully used for decreasing the water content of ceramic slips for casting and spray drying.

  10. Machines that walk: The adaptive suspension vehicle

    NASA Astrophysics Data System (ADS)

    Song, Shin-Min; Waldron, Kenneth J.

    The design and operation of statically stable fully terrain-adaptive walking machines are discussed, with an emphasis on the adaptive-suspension vehicle developed at Ohio State University (Waldron and McGhee, 1986). Chapters are devoted to a review of walking-machine development, gait analysis and gaits for level walking, gaits for irregular terrain, coordination, leg design by four-bar linkage synthesis, design of a pantograph leg, motion-controlled ankle design, and the Adaptive Suspension Vehicle. Diagrams, drawings, and graphs are provided.

  11. Suspension Hydrogen Reduction of Iron Oxide Concentrates

    SciTech Connect

    H.Y. Sohn

    2008-03-31

    The objective of the project is to develop a new ironmaking technology based on hydrogen and fine iron oxide concentrates in a suspension reduction process. The ultimate objective of the new technology is to replace the blast furnace and to drastically reduce CO2 emissions in the steel industry. The goals of this phase of development are; the performance of detailed material and energy balances, thermochemical and equilibrium calculations for sulfur and phosphorus impurities, the determination of the complete kinetics of hydrogen reduction and bench-scale testing of the suspension reduction process using a large laboratory flash reactor.

  12. A comparison between two pneumatic suspension architectures

    NASA Astrophysics Data System (ADS)

    Quaglia, G.; Scopesi, M.; Franco, W.

    2012-04-01

    The aim of this work is to assess and compare the mathematical models of two pneumatic suspension architectures and show how they can converge, after appropriate simplifications, to a general linear form. After making this model dimensionless, it will be used to study, with a transmissibility analysis, the behaviour of a mono-suspension (quarter-car model). Finally, an example of a design process will be shown to highlight the strengths and weaknesses of both architectures and to provide the reader with a practical design tool.

  13. Soft Sphere Suspensions: Flow and Relaxation

    NASA Astrophysics Data System (ADS)

    Workamp, Marcel; Dijksman, Joshua A.

    We experimentally study the role of particle elasticity on the rheology of soft sphere suspensions. Experiments consist of custom designed particles with tuneable stiffness. These particles allow us to probe the role of elastic timescales, relaxation and anisotropy in a custom 3D printed shear cell. We find robust rheological features, such as a flow instability, that are not well captured by existing models for suspension flows. In addition, we find relaxation effects after shear even in the absence of shear or thermal fluctuations. We aim to integrate these findings in the emerging unified framework for structured fluids.

  14. Solid freeform fabrication using chemically reactive suspensions

    DOEpatents

    Morisette, Sherry L.; Cesarano, III, Joseph; Lewis, Jennifer A.; Dimos, Duane B.

    2002-01-01

    The effects of processing parameters and suspension chemorheology on the deposition behavior of SFF components derived from polymeric-based gelcasting suspensions combines the advantages associated with SFF fabrication, including the ability to spatially tailor composition and structure as well as reduced tooling costs, with the improved handling strength afforded by the use of gel based formulations. As-cast free-formed Al.sub.2 O.sub.3 components exhibited uniform particle packing and had minimal macro-defects (e.g., slumping or stair casing) and no discernable micro-defects (e.g., bubbles or cracking).

  15. Unifying Suspension and Granular flows near Jamming

    NASA Astrophysics Data System (ADS)

    DeGiuli, Eric; Wyart, Matthieu

    2017-06-01

    Rheological properties of dense flows of hard particles are singular as one approaches the jamming threshold where flow ceases, both for granular flows dominated by inertia, and for over-damped suspensions. Concomitantly, the lengthscale characterizing velocity correlations appears to diverge at jamming. Here we review a theoretical framework that gives a scaling description of stationary flows of frictionless particles. Our analysis applies both to suspensions and inertial flows of hard particles. We report numerical results in support of the theory, and show the phase diagram that results when friction is added, delineating the regime of validity of the frictionless theory.

  16. Noncovalent Functionalization of Graphene in Suspension

    PubMed Central

    Yang, Wenzhi; Akhtar, Sultan; Leifer, Klaus

    2013-01-01

    Suspensions of graphene, prepared from graphite foil by sonochemical exfoliation, have been treated with new nonpolar pyrenebutyric amides. The assemblies, in suspension and after deposition on solid supports, were characterized by NMR, absorption, and fluorescence spectroscopy and by transmission electron microscopy, where the well-defined shape and size of an appended [60]fulleropyrrolidine unit facilitates TEM detection of the nonstationary molecules. The accumulated evidence, also including direct comparisons of carbon nanotubes treated with pyrene amides under the same conditions, proves the successful noncovalent functionalization of graphene suspended in non-polar solvent with non-polar pyrene derivatives. PMID:24052867

  17. Third International Symposium on Magnetic Suspension Technology

    NASA Technical Reports Server (NTRS)

    Groom, Nelson J. (Editor); Britcher, Colin P. (Editor)

    1996-01-01

    In order to examine the state of technology of all areas of magnetic suspension and to review recent developments in sensors, controls, superconducting magnet technology, and design/implementation practices, the Third International Symposium on Magnetic Suspension Technology was held at the Holiday Inn Capital Plaza in Tallahassee, Florida on 13-15 Dec. 1995. The symposium included 19 sessions in which a total of 55 papers were presented. The technical sessions covered the areas of bearings, superconductivity, vibration isolation, maglev, controls, space applications, general applications, bearing/actuator design, modeling, precision applications, electromagnetic launch and hypersonic maglev, applications of superconductivity, and sensors.

  18. Carbon nanotube suspensions, dispersions, & composites

    NASA Astrophysics Data System (ADS)

    Simmons, Trevor John

    Carbon Nanotubes (CNTs) are amazing structures that hold the potential to revolutionize many areas of scientific research. CNTs can be behave both as semiconductors and metals, can be grown in highly ordered arrays and patterns or in random orientation, and can be comprised of one graphene cylinder (single wall nanotube, SWNT) or several concentric graphene cylinders (multi-wall nanotube, MWNT). Although these structures are usually only a few nanometers wide, they can be grown up to centimeter lengths, and in massive quantities. CNTs can be produced in a variety of processes ranging from repeated combustion of organic material such as dried grass, arc-discharge with graphite electrodes, laser ablation of a graphitic target, to sophisticated chemical vapor deposition (CVD) techniques. CNTs are stronger than steel but lighter than aluminum, and can be more conductive than copper or semiconducting like silicon. This variety of properties has been matched by the wide variety of applications that have been developed for CNTs. Many of these applications have been limited by the inability of researchers to tame these structures, and incorporating CNTs into existing technologies can be exceedingly difficult and prohibitively expensive. It is therefore the aim of the current study to develop strategies for the solution processing and deposition of CNTs and CNT-composites, which will enable the use of CNTs in existing and emerging technologies. CNTs are not easily suspended in polar solvents and are extremely hydrophobic materials, which has limited much of the solution processing to organic solvents, which also cannot afford high quality dispersions of CNTs. The current study has developed a variety of aqueous CNT solutions that employ surfactants, water-soluble polymers, or both to create suspensions of CNTs. These CNT 'ink' solutions were deposited with a variety of techniques that have afforded many interesting structures, both randomly oriented as well as highly

  19. 44 CFR 17.615 - Grounds for suspension of payments, suspension or termination of grants, or suspension or debarment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... to make a good faith effort to provide a drug-free workplace. (c) With respect to a grantee who is an... GOVERNMENTWIDE REQUIREMENTS FOR DRUG-FREE WORKPLACE (GRANTS) § 17.615 Grounds for suspension of payments... writing, that— (a) The grantee has made a false certification under § 17.630; (b) With respect to a...

  20. Etude du comportement rheologique de suspensions colloidales

    NASA Astrophysics Data System (ADS)

    Yziquel, Florence

    Colloidal suspensions exhibit complex rheological behavior. The particles interact between themselves with forces of which the nature and magnitude depend on the surrounding medium. When the forces are strong enough, this organized structure which can be broken down, distorted or rearranged under shear flow. Hence, the suspension rheology depends greatly on the structure evolution during the flow. The main objective of this work was to propose a rheological model to describe the suspension behavior taking the structure evolution into account. To understand the rheological behavior of these systems, two different suspensions have been studied. The first system is a "model" suspension of fumed silica particles. These colloidal particles interact between themselves through hydrogen bonds with silanol groups on their surface inducing a network formation even at small mass fraction. The rheological properties of particles in suspension in polar and nonpolar media were studied as functions of size, concentration and surface treatment of particles. The rheological behavior, for small strain amplitude oscillatory flow, is strongly nonlinear. These nonlinear viscoelastic properties have been interpreted in terms of dissipated energy and attributed to the network breakdown. The experimental data have been compared with Coussot and Oldroyd modified models predictions. These two models only describe qualitatively the rheological behavior of fumed silica suspensions in nonpolar media. The second system studied here is a coating color. This concentrated suspension is mainly composed by kaolin particles sterically stabilized by water-soluble polymer adsorbed on their surface. The steady shear viscosity and the dynamic properties have been studied as a function of polymer concentration for two different water-soluble polymers. It was shown that the rheological properties are controlled by the structure evolution under shear flow. A structural model has been proposed to describe

  1. Rheological Properties of Aqueous Nanometric Alumina Suspensions

    SciTech Connect

    Li, Chuanping

    2004-01-01

    Colloidal processing is an effective and reliable approach in the fabrication of the advanced ceramic products. Successful colloidal processing of fine ceramic powders requires accurate control of the rheological properties. The accurate control relies on the understanding the influences of various colloidal parameters on the rheological properties. Almost all research done on the rheology paid less attention to the interactions of particle and solvent. However, the interactions of the particles are usually built up through the media in which the particles are suspended. Therefore, interactions of the particle with the media, the adsorbed layers on the particle surface, and chemical and physical properties of media themselves must influence the rheology of the suspension, especially for the dense suspensions containing nanosized particles. Relatively little research work has been reported in this area. This thesis addresses the rheological properties of nanometric alumina aqueous suspensions, and paying more attention to the interactions between particle and solvent, which in turn influence the particle-particle interactions. Dense nanometric alumina aqueous suspensions with low viscosity were achieved by environmentally-benign fructose additives. The rheology of nanometric alumina aqueous suspensions and its variation with the particle volume fraction and concentration of fructose were explored by rheometry. The adsorptions of solute (fructose) and solvent (water) on the nanometric alumina particle surfaces were measured and analyzed by TG/DSC, TOC, and NMR techniques. The mobility of water molecules in the suspensions and its variation with particle volume fractions and fructose additive were determined by the 17O NMR relaxation method. The interactions between the nanometric alumina particles in water and fructose solutions were investigated by AFM. The results indicated that a large number of water layers were physically bound on the particles

  2. 15 CFR 2011.207 - Suspension of the certificate system.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... OFFICE OF THE UNITED STATES TRADE REPRESENTATIVE ALLOCATION OF TARIFF-RATE QUOTA ON IMPORTED SUGARS, SYRUPS AND MOLASSES Specialty Sugar § 2011.207 Suspension of the certificate system. (a) Suspension....

  3. 15 CFR 2011.207 - Suspension of the certificate system.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... OFFICE OF THE UNITED STATES TRADE REPRESENTATIVE ALLOCATION OF TARIFF-RATE QUOTA ON IMPORTED SUGARS, SYRUPS AND MOLASSES Specialty Sugar § 2011.207 Suspension of the certificate system. (a) Suspension. The...

  4. 15 CFR 2011.207 - Suspension of the certificate system.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... OFFICE OF THE UNITED STATES TRADE REPRESENTATIVE ALLOCATION OF TARIFF-RATE QUOTA ON IMPORTED SUGARS, SYRUPS AND MOLASSES Specialty Sugar § 2011.207 Suspension of the certificate system. (a) Suspension. The...

  5. 39 CFR 954.6 - Revocation or suspension.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... DENIAL, SUSPENSION, OR REVOCATION OF PERIODICALS MAIL PRIVILEGES § 954.6 Revocation or suspension. When the authorized official determines that a publication is no longer entitled to Periodicals mailing...

  6. 39 CFR 954.6 - Revocation or suspension.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... DENIAL, SUSPENSION, OR REVOCATION OF PERIODICALS MAIL PRIVILEGES § 954.6 Revocation or suspension. When the authorized official determines that a publication is no longer entitled to Periodicals mailing...

  7. 39 CFR 954.6 - Revocation or suspension.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... DENIAL, SUSPENSION, OR REVOCATION OF PERIODICALS MAIL PRIVILEGES § 954.6 Revocation or suspension. When the authorized official determines that a publication is no longer entitled to Periodicals mailing...

  8. 39 CFR 954.6 - Revocation or suspension.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... DENIAL, SUSPENSION, OR REVOCATION OF PERIODICALS MAIL PRIVILEGES § 954.6 Revocation or suspension. When the authorized official determines that a publication is no longer entitled to Periodicals mailing...

  9. 39 CFR 954.6 - Revocation or suspension.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... DENIAL, SUSPENSION, OR REVOCATION OF PERIODICALS MAIL PRIVILEGES § 954.6 Revocation or suspension. When the authorized official determines that a publication is no longer entitled to Periodicals mailing...

  10. Decoupling Suspension Controller Based on Magnetic Flux Feedback

    PubMed Central

    Zhang, Wenqing; Li, Jie; Zhang, Kun; Cui, Peng

    2013-01-01

    The suspension module control system model has been established based on MIMO (multiple input and multiple output) state feedback linearization. We have completed decoupling between double suspension points, and the new decoupling method has been applied to CMS04 magnetic suspension vehicle in national mid-low-speed maglev experiment field of Tangshan city in China. Double suspension system model is very accurate for investigating stability property of maglev control system. When magnetic flux signal is taken back to the suspension control system, the suspension module's antijamming capacity for resisting suspension load variety has been proved. Also, the external force interference has been enhanced. As a result, the robustness and stability properties of double-electromagnet suspension control system have been enhanced. PMID:23844415

  11. Decoupling suspension controller based on magnetic flux feedback.

    PubMed

    Zhang, Wenqing; Li, Jie; Zhang, Kun; Cui, Peng

    2013-01-01

    The suspension module control system model has been established based on MIMO (multiple input and multiple output) state feedback linearization. We have completed decoupling between double suspension points, and the new decoupling method has been applied to CMS04 magnetic suspension vehicle in national mid-low-speed maglev experiment field of Tangshan city in China. Double suspension system model is very accurate for investigating stability property of maglev control system. When magnetic flux signal is taken back to the suspension control system, the suspension module's antijamming capacity for resisting suspension load variety has been proved. Also, the external force interference has been enhanced. As a result, the robustness and stability properties of double-electromagnet suspension control system have been enhanced.

  12. 22 CFR 513.411 - Notice of suspension.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... respondent on notice without disclosing the Federal Government's evidence; (d) Of the cause(s) relied upon... procedures, if applicable, governing suspension decisionmaking; and (g) Of the effect of the suspension....

  13. 22 CFR 513.411 - Notice of suspension.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... respondent on notice without disclosing the Federal Government's evidence; (d) Of the cause(s) relied upon... procedures, if applicable, governing suspension decisionmaking; and (g) Of the effect of the suspension....

  14. 78 FR 12106 - Debarment, Suspension, and Ineligibility of Contractors

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-21

    ... MANAGEMENT Debarment, Suspension, and Ineligibility of Contractors AGENCY: U.S. Office of Personnel... (FAR) regarding the debarment, suspension, and ineligibility of government contractors. As an executive... those entities and individuals (hereinafter, contractors) who are responsible. To make clear that...

  15. 48 CFR 1480.505 - Debarment and suspension.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... suspension in accordance with FAR 9.406 and 9.407. IA must refer recommendations for debarment or suspension... accordance with DIAR 1409.406 and 1409.407 through the IA Division of Acquisitions with the concurrence...

  16. The middeck active control experiment: Gravity and suspension effects

    NASA Technical Reports Server (NTRS)

    Crawley, Edward F.; Alexander, H.; Rey, Daniel

    1992-01-01

    Viewgraphs on the Middeck Active Control Experiment (MACE): Gravity and Suspension Effects are presented. Topics covered include: gravity and suspension influences; gravity and suspension effects on structure; gravity effects on sensors and actuators; modeling of gravity and suspension effects on structure; geometric stiffness theory and initial static deformation calculation; modeling gravity's effect on accelerometers and PMA's; application to MACE; MACE EM configuration study; and MACE DM configuration study.

  17. 45 CFR 1206.1-4 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... complicated as a result of granting such permission, and the extent to which the interests of the agency... effective upon delivery. Suspension shall not exceed 30 days unless during such period of time termination... letter or by telegram, shall become effective upon delivery to the recipient, and shall specifically...

  18. 21 CFR 520.1618 - Orbifloxacin suspension.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.1618 Orbifloxacin suspension... use of this drug in food-producing animals. (d) Conditions of use—(1) Dogs—(i) Amount. 1.1 to 3.4 mg... urinary tract infections (cystitis) in dogs caused by susceptible strains of Staphylococcus...

  19. 21 CFR 520.1618 - Orbifloxacin suspension.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.1618 Orbifloxacin suspension... use of this drug in food-producing animals. (d) Conditions of use—(1) Dogs—(i) Amount. 1.1 to 3.4 mg... urinary tract infections (cystitis) in dogs caused by susceptible strains of Staphylococcus...

  20. 21 CFR 520.1618 - Orbifloxacin suspension.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.1618 Orbifloxacin suspension... use of this drug in food-producing animals. (d) Conditions of use—(1) Dogs—(i) Amount. 1.1 to 3.4 mg... urinary tract infections (cystitis) in dogs caused by susceptible strains of Staphylococcus...

  1. 21 CFR 520.1618 - Orbifloxacin suspension.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.1618 Orbifloxacin suspension... use of this drug in food-producing animals. (d) Conditions of use—(1) Dogs—(i) Amount. 1.1 to 3.4 mg... urinary tract infections (cystitis) in dogs caused by susceptible strains of Staphylococcus...

  2. 24 CFR 1710.45 - Suspensions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 5 2014-04-01 2014-04-01 false Suspensions. 1710.45 Section 1710.45 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR HOUSING-FEDERAL HOUSING COMMISSIONER, DEPARTMENT OF HOUSING AND...

  3. 32 CFR 552.80 - Suspension period.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 3 2010-07-01 2010-07-01 true Suspension period. 552.80 Section 552.80 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY MILITARY RESERVATIONS AND NATIONAL CEMETERIES REGULATIONS AFFECTING MILITARY RESERVATIONS Solicitation on Military Reservations §...

  4. 32 CFR 552.77 - Suspension approval.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 3 2010-07-01 2010-07-01 true Suspension approval. 552.77 Section 552.77 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY MILITARY RESERVATIONS AND NATIONAL CEMETERIES REGULATIONS AFFECTING MILITARY RESERVATIONS Solicitation on Military Reservations §...

  5. 32 CFR 552.79 - Suspension action.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 3 2010-07-01 2010-07-01 true Suspension action. 552.79 Section 552.79 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY MILITARY RESERVATIONS AND NATIONAL CEMETERIES REGULATIONS AFFECTING MILITARY RESERVATIONS Solicitation on Military Reservations §...

  6. Tangential Ultrafiltration of Aqueous "Saccharomyces Cerevisiae" Suspensions

    ERIC Educational Resources Information Center

    Silva, Carlos M.; Neves, Patricia S.; Da Silva, Francisco A.; Xavier, Ana M. R. B.; Eusebio, M. F. J.

    2008-01-01

    Experimental work on ultrafiltration is presented to illustrate the practical and theoretical principles of this separation technique. The laboratory exercise comprises experiments with pure water and with aqueous "Saccharomyces cerevisiae" (from commercial Baker's yeast) suspensions. With this work students detect the characteristic phenomena…

  7. 25 CFR 558.5 - License suspension.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... INDIAN GAMING COMMISSION, DEPARTMENT OF THE INTERIOR GAMING LICENSES AND BACKGROUND INVESTIGATIONS FOR KEY EMPLOYEES AND PRIMARY MANAGEMENT OFFICIALS GAMING LICENSES FOR KEY EMPLOYEES AND PRIMARY MANAGEMENT OFFICIALS § 558.5 License suspension. (a) If, after the issuance of a gaming license, the...

  8. 25 CFR 558.5 - License suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... INDIAN GAMING COMMISSION, DEPARTMENT OF THE INTERIOR GAMING LICENSES AND BACKGROUND INVESTIGATIONS FOR KEY EMPLOYEES AND PRIMARY MANAGEMENT OFFICIALS GAMING LICENSES FOR KEY EMPLOYEES AND PRIMARY MANAGEMENT OFFICIALS § 558.5 License suspension. (a) If, after the issuance of a gaming license, the...

  9. Electrorheology of suspensions containing interfacially active constituents.

    PubMed

    McIntyre, Carl; Yang, Hengxi; Green, Peter F

    2013-09-25

    We recently showed that a suspension of micrometer-sized polystyrene (PS) particles in a PDMS liquid, mixed with small (1 wt %) amounts of a nanocage, sulfonated polyhedral oligomeric silsesquioxane (s-POSS), exhibited significant electrorheological (ER) behavior. This behavior was associated with the formation of a thin adsorbed layer of s-POSS onto the surfaces of PS and the subsequent formation of polarization-induced aggregates, or structures, responsible for the ER effect in an applied electric, E, field. Current theory suggests that the ER effect would largely be determined by the dielectric and conductive properties of the conductive layer of core/shell particles in ER suspensions. We show here that sulfonated-PS (s-PS)/PDMS suspensions exhibit further increases in the yield stress of over 200%, with the addition of s-POSS. The yield stress of this system, moreover, scales as τy [proportionality] E(2). The dielectric relaxation studies reveal the existence of a new relaxation peak in the s-POSS/s-PS/PDMS system that is absent in the s-POSS/PS/PDMS suspension. The relative sizes of these peaks are sensitive to the concentration of s-POSS and are associated with changes in the ER behavior. The properties of this class of ER fluids are not appropriately rationalized in terms of current theories.

  10. Dewatering of fibre suspensions by pressure filtration

    NASA Astrophysics Data System (ADS)

    Hewitt, Duncan R.; Paterson, Daniel T.; Balmforth, Neil J.; Martinez, D. Mark

    2016-06-01

    A theoretical and experimental study of dewatering of fibre suspensions by uniaxial compression is presented. Solutions of a one-dimensional model are discussed and asymptotic limits of fast and slow compression are explored. Particular focus is given to relatively rapid compression and to the corresponding development of spatial variations in the solidity and velocity profiles of the suspension. The results of complementary laboratory experiments are presented for nylon or cellulose fibres suspended in viscous fluid. The constitutive relationships for each suspension were measured independently. Measurements of the load for different fixed compression speeds, together with some direct measurements of the velocity profiles using particle tracking velocimetry, are compared with model predictions. The comparison is reasonable for nylon, but poor for cellulose fibres. An extension to the model, which allows for a strain-rate-dependent component in the network stress, is proposed, and is found to give a dramatic improvement in the model predictions for cellulose fibre suspensions. The reason for this improvement is attributed to the microstructure of cellulose fibres, which, unlike nylon fibres, are themselves porous.

  11. Air-Bearing-Piston Suspension System

    NASA Technical Reports Server (NTRS)

    Mullen, Donald; Bishop, Stephen J.

    1992-01-01

    Suspension system based on air-bearing piston holds up steel ball against gravitation while allowing ball to translate vertically and rotate freely. System designed to simulate effect of microgravity on ball. Applicable to suppression of vibrations and delicate machining processes.

  12. 36 CFR 223.141 - Suspension.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 2 2013-07-01 2013-07-01 false Suspension. 223.141 Section 223.141 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE SALE AND DISPOSAL OF NATIONAL FOREST SYSTEM TIMBER, SPECIAL FOREST PRODUCTS, AND FOREST BOTANICAL...

  13. 36 CFR 223.141 - Suspension.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 2 2012-07-01 2012-07-01 false Suspension. 223.141 Section 223.141 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE SALE AND DISPOSAL OF NATIONAL FOREST SYSTEM TIMBER, SPECIAL FOREST PRODUCTS, AND FOREST BOTANICAL...

  14. 34 CFR 682.705 - Suspension proceedings.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 34 Education 4 2011-07-01 2011-07-01 false Suspension proceedings. 682.705 Section 682.705 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY EDUCATION, DEPARTMENT OF EDUCATION (CONTINUED) FEDERAL FAMILY EDUCATION LOAN (FFEL) PROGRAM...

  15. 34 CFR 682.705 - Suspension proceedings.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 34 Education 4 2012-07-01 2012-07-01 false Suspension proceedings. 682.705 Section 682.705 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY EDUCATION, DEPARTMENT OF EDUCATION (CONTINUED) FEDERAL FAMILY EDUCATION LOAN (FFEL) PROGRAM...

  16. 34 CFR 682.705 - Suspension proceedings.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 34 Education 4 2014-07-01 2014-07-01 false Suspension proceedings. 682.705 Section 682.705 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY EDUCATION, DEPARTMENT OF EDUCATION (CONTINUED) FEDERAL FAMILY EDUCATION LOAN (FFEL) PROGRAM...

  17. 34 CFR 682.705 - Suspension proceedings.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 34 Education 4 2013-07-01 2013-07-01 false Suspension proceedings. 682.705 Section 682.705 Education Regulations of the Offices of the Department of Education (Continued) OFFICE OF POSTSECONDARY EDUCATION, DEPARTMENT OF EDUCATION (CONTINUED) FEDERAL FAMILY EDUCATION LOAN (FFEL) PROGRAM...

  18. 76 FR 25656 - Responsibility; Suspension and Debarment

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-05

    ... SPACE ADMINISTRATION 48 CFR Part 1809 RIN 2700-AD54 Responsibility; Suspension and Debarment AGENCY... by addressing the non-responsibility issues. This proposed rule is consistent with FAR 9.104-6... FAPIIS to obtain pre-award information, and to enter determinations of non- responsibility for...

  19. Nucleonic coal detector with independent, hydropneumatic suspension

    NASA Technical Reports Server (NTRS)

    Jones, E. W.; Handy, K.

    1977-01-01

    The design of a nucleonic, coal interface detector which measures the depth of coal on the roof and floor of a coal mine is presented. The nucleonic source and the nucleonic detector are on independent hydropneumatic suspensions to reduce the measurement errors due to air gap.

  20. Numerical Study of Suspension Plasma Spraying

    NASA Astrophysics Data System (ADS)

    Farrokhpanah, Amirsaman; Coyle, Thomas W.; Mostaghimi, Javad

    2017-01-01

    A numerical study of suspension plasma spraying is presented in the current work. The liquid suspension jet is replaced with a train of droplets containing the suspension particles injected into the plasma flow. Atomization, evaporation, and melting of different components are considered for droplets and particles as they travel toward the substrate. Effect of different parameters on particle conditions during flight and upon impact on the substrate is investigated. Initially, influence of the torch operating conditions such as inlet flow rate and power is studied. Additionally, effect of injector parameters like injection location, flow rate, and angle is examined. The model used in the current study takes high-temperature gradients and non-continuum effects into account. Moreover, the important effect of change in physical properties of suspension droplets as a result of evaporation is included in the model. These mainly include variations in heat transfer properties and viscosity. Utilizing this improved model, several test cases have been considered to better evaluate the effect of different parameters on the quality of particles during flight and upon impact on the substrate.

  1. Discipline of Handicapped Students: Suspension and Expulsion.

    ERIC Educational Resources Information Center

    Parrish, Patricia

    This paper discusses the suspension and expulsion of unruly handicapped students by examining previous court litigation, identifying the legal issues involved, and reviewing Texas State Board of Education policy. Although sensitive and knowledgeable of the special learning and emotional needs of handicapped students, the conclusion favors recent…

  2. 25 CFR 558.5 - License suspension.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... INDIAN GAMING COMMISSION, DEPARTMENT OF THE INTERIOR GAMING LICENSES AND BACKGROUND INVESTIGATIONS FOR KEY EMPLOYEES AND PRIMARY MANAGEMENT OFFICIALS GAMING LICENSES FOR KEY EMPLOYEES AND PRIMARY MANAGEMENT OFFICIALS § 558.5 License suspension. (a) If, after the issuance of a gaming license,...

  3. 21 CFR 26.16 - Suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Suspension. 26.16 Section 26.16 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL MUTUAL RECOGNITION OF PHARMACEUTICAL GOOD MANUFACTURING PRACTICE REPORTS, MEDICAL DEVICE QUALITY SYSTEM AUDIT REPORTS, AND CERTAIN...

  4. Baltimore District Tackles High Suspension Rates

    ERIC Educational Resources Information Center

    Maxwell, Lesli A.

    2007-01-01

    This article reports on how the Baltimore District tackles its high suspension rates. Driven by an increasing belief that zero-tolerance disciplinary policies are ineffective, more educators are embracing strategies that do not exclude misbehaving students from school for offenses such as insubordination, disrespect, cutting class, tardiness, and…

  5. Impact response of shear thickening suspensions

    NASA Astrophysics Data System (ADS)

    Brown, Eric; Ozgen, Oktar; Kallmann, Marcelo; Allen, Benjamin

    2013-11-01

    Dense suspensions of hard particles such as cornstarch in water exhibit shear thickening, in which the energy dissipation rate under shear dramatically increases with increasing shear rate. Recent work has established that in steady-state shear this phenomena is a result of a dynamic jamming of the particles in suspension. Several dynamic phenomena observed in such suspensions have long been assumed to be a consequence of this shear thickening; strong impact resistance, the ability of a person to run on the fluid surface, fingering and hole instabilities under vibration, and oscillations in the speed of sinking of an object in the fluid. However, I will present results of experiments consisting of an indenter impacting a dense suspension which demonstrate that the strong impact resistance cannot be explained by existing models for steady-state shear thickening. I will show these dynamic phenomena can be reproduced by graphical simulations based on a minimal phenomenological model in which the fluid has a stiffness with a dependence on velocity history. These and other recent results suggest a need for new models to understand the dynamic phenomena associated with shear thickening fluids.

  6. Mathematical modelling of an electromagnetics automobile suspension

    NASA Astrophysics Data System (ADS)

    Amin, Ahmad Zaki Mohamad; Ahmad, Shamsuddin; Hoe, Yeak Su

    2017-04-01

    The mathematical modelling of the electromagnetic automobile suspension (EAS) is presented. The solution of the model is found using Runge-Kutta Method via MAPLE. The graphs of the vertical displacement, different vertical displacement and road profiles and acceleration of car body against time are investigated and validated using certain criteria.

  7. Tangential Ultrafiltration of Aqueous "Saccharomyces Cerevisiae" Suspensions

    ERIC Educational Resources Information Center

    Silva, Carlos M.; Neves, Patricia S.; Da Silva, Francisco A.; Xavier, Ana M. R. B.; Eusebio, M. F. J.

    2008-01-01

    Experimental work on ultrafiltration is presented to illustrate the practical and theoretical principles of this separation technique. The laboratory exercise comprises experiments with pure water and with aqueous "Saccharomyces cerevisiae" (from commercial Baker's yeast) suspensions. With this work students detect the characteristic phenomena…

  8. Hyper-aging dynamics of nanoclay suspension.

    PubMed

    Shahin, A; Joshi, Yogesh M

    2012-04-03

    Aqueous suspension of nanoclay Laponite undergoes structural evolution as a function of time, which enhances its elasticity and relaxation time. In this work, we employ an effective time approach to investigate long-term relaxation dynamics by carrying out creep experiments. Typically, we observe that the monotonic evolution of elastic modulus shifts to lower aging times, while maxima in viscous moduli get progressively broader for experiments carried out on a later date after preparation (idle time) of the nanoclay suspension. Application of effective time theory produces a superposition of all the creep curves irrespective of their initial state. The resulting dependence of the relaxation time on aging time shows very strong hyper-aging dynamics at short idle times, which progressively weakens to demonstrate a linear dependence in the limit of very long idle times. Remarkably, this behavior of nanoclay suspensions is akin to that observed for polymeric glasses. Consideration of aging as a first-order process suggests that continued hyper-aging dynamics causes cessation of aging. The dependence of relaxation time on aging time, therefore, must attenuate eventually producing linear or weaker dependence on time in order to approach a progressively low-energy state in the limit of very long times as observed experimentally. We also develop a simple scaling model based on a concept of aging of an energy well, which qualitatively captures various experimental observations very well, leading to profound insight into the hyper-aging dynamics of nanoclay suspensions.

  9. Electroneutrality and phase behavior of colloidal suspensions

    NASA Astrophysics Data System (ADS)

    Denton, A. R.

    2007-11-01

    Several statistical mechanical theories predict that colloidal suspensions of highly charged macroions and monovalent microions can exhibit unusual thermodynamic phase behavior when strongly deionized. Density-functional, extended Debye-Hückel, and response theories, within mean-field and linearization approximations, predict a spinodal phase instability of charged colloids below a critical salt concentration. Poisson-Boltzmann cell model studies of suspensions in Donnan equilibrium with a salt reservoir demonstrate that effective interactions and osmotic pressures predicted by such theories can be sensitive to the choice of reference system, e.g., whether the microion density profiles are expanded about the average potential of the suspension or about the reservoir potential. By unifying Poisson-Boltzmann and response theories within a common perturbative framework, it is shown here that the choice of reference system is dictated by the constraint of global electroneutrality. On this basis, bulk suspensions are best modeled by density-dependent effective interactions derived from a closed reference system in which the counterions are confined to the same volume as the macroions. Lower-dimensional systems (e.g., monolayers, clusters), depending on the strength of macroion-counterion correlations, may be governed instead by density-independent effective interactions tied to an open reference system with counterions dispersed throughout the reservoir, possibly explaining the observed structural crossover in colloidal monolayers and anomalous metastability of colloidal crystallites.

  10. 75 FR 22263 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-28

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOMELAND SECURITY Federal Emergency Management Agency 44 CFR Part 64 Suspension of Community Eligibility Correction In rule document 2010-2487 beginning on page 5890 in the issue of February 5, 2010 make the...

  11. Baltimore District Tackles High Suspension Rates

    ERIC Educational Resources Information Center

    Maxwell, Lesli A.

    2007-01-01

    This article reports on how the Baltimore District tackles its high suspension rates. Driven by an increasing belief that zero-tolerance disciplinary policies are ineffective, more educators are embracing strategies that do not exclude misbehaving students from school for offenses such as insubordination, disrespect, cutting class, tardiness, and…

  12. Dynamic shear jamming in dense suspensions

    NASA Astrophysics Data System (ADS)

    Peters, Ivo; Majumdar, Sayantan; Jaeger, Heinrich

    Shear a dense suspension of cornstarch and water hard enough, and the system seems to solidify as a result. Indeed, previous studies have shown that a jamming front propagates through these systems until, after interaction with boundaries, a jammed solid spans across the system. Because these fully jammed states are only observed if the deformation is fast enough, a natural question to ask is how this phenomenon is related to the discontinuous shear thickening (DST) behavior of these suspensions. We present a single experimental setup in which we on the one hand can measure the rheological flow curves, but on the other hand also determine if the suspension is in a jammed state. This we do by using a large-gap cylindrical Couette cell, where we control the applied shear stress using a rheometer. Because our setup only applies shear, the jammed states we observe are shear-jammed, and cannot be a result of an overall increase in packing fraction. We probe for jammed states by dropping small steel spheres on the surface of the suspension, and identify elastic responses. Our experiments reveal a clear distinction between the onset of DST and Shear-Jammed states, which have qualitatively different trends with packing fraction close to the isotropic jamming point.

  13. Regenerative magnetorheological dampers for vehicle suspensions

    NASA Astrophysics Data System (ADS)

    Chen, Chao; Zou, Li; Liao, Wei-Hsin

    2015-04-01

    Magnetorheological (MR) dampers are promising for vehicle suspensions, by virtue of their adaptive properties. During the everyday use of vehicles, a lot of energy is wasted due to the energy dissipation by dampers under the road irregularities. On the other hand, extra batteries are required for the current MR damper systems. To reduce the energy waste and get rid of the dependence on extra batteries, in this paper, regenerative MR dampers are proposed for vehicle suspensions, which integrate energy harvesting and controllable damping functions. The wasted vibration energy can be converted into electrical energy and power the MR damper coil. A regenerative MR damper for vehicle suspensions is developed. Damping force and power generation characteristics of the regenerative MR damper were modeled and analyzed. Then the damper is applied to a 2 DOF suspension system for system simulation under various road conditions. Simulation results show that riding comfort can be significantly improved, while harvesting energy for other use in addition to supply power for the controlled MR damper.

  14. 36 CFR 25.3 - Supervision; suspensions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ....3 Section 25.3 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL MILITARY PARKS; LICENSED GUIDE SERVICE REGULATIONS § 25.3 Supervision; suspensions. (a) The guide service will operate under the direction of the superintendent or his designated representative....

  15. "Restorative Practices" Offer Alternatives to Suspension

    ERIC Educational Resources Information Center

    Shah, Nirvi

    2012-01-01

    At City Springs and many other schools across the country, restorative practices are about holding students accountable and getting them to right a wrong. The approach is getting more notice than ever as criticism grows of zero-tolerance disciplinary policies that often require out-of-school suspension and expulsion. Educators are turning to…

  16. Formation of Aqueous Suspensions of Fullerenes

    EPA Science Inventory

    Colloidal suspensions of C60, C70 and a derivative of C60, PCBM ([6,6]-Phenyl C61-butyric acid methyl ester) were produced by extended mixing in water. We examined the contribution of background solution chemistry (pH, ionic strength) on the formation kinetics of colloidal suspe...

  17. Developing Effective In-School-Suspension Programs.

    ERIC Educational Resources Information Center

    Vanderslice, Ronna

    Discipline--the most serious problem faced by teachers today--has consistently appeared at or near the top of the public's attitudes toward the public schools. This paper discusses the difficulty of discipline and one of the most perplexing problems facing administrators today--the use of suspension as a discipline alternative. Out-of-school…

  18. Formation of Aqueous Suspensions of Fullerenes

    EPA Science Inventory

    Colloidal suspensions of C60, C70 and a derivative of C60, PCBM ([6,6]-Phenyl C61-butyric acid methyl ester) were produced by extended mixing in water. We examined the contribution of background solution chemistry (pH, ionic strength) on the formation kinetics of colloidal suspe...

  19. Yield stress of alumina-zirconia suspensions

    SciTech Connect

    Ramakrishnan, V.; Pradip; Malghan, S.G.

    1996-10-01

    The yield stress of concentrated suspensions of alumina, zirconia, and mixed alumina-zirconia powders was measured by the vane technique as a function of solids loading, relative amounts of alumina and zirconia, and pH. At the isoelectric point (IEP), the yield stress varied as the fourth power of the solids loading. The relative ratio of alumina and zirconia particles was important in determining the yield stress of the suspension at the IEP. The yield stress of single and mixed suspensions showed a marked variation with pH. The maximum value occurred at or near the IEP of the suspension. The effect of electrical double-layer forces on the yield stress can be described on the basis of the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. A normalized yield stress--that is, the ratio of the yield stress at a given pH to the yield stress at the IEP predicted by this model--showed good correlation with experimental data.

  20. 77 FR 39642 - Suspension of Community Eligibility

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-05

    ... this rule because of noncompliance with the floodplain management requirements of the program. If the... required floodplain management measures prior to the effective suspension date given in this rule, the... floodplain management measures aimed at protecting lives and new construction from future flooding. Section...