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Sample records for pressure-controlled ventilation pcv

  1. Comparison of three ventilatory modes during one-lung ventilation in elderly patients

    PubMed Central

    Lin, Fei; Pan, Linghui; Qian, Wei; Ge, Wanyun; Dai, Huijun; Liang, Yubing

    2015-01-01

    Objective: The purpose of this study was to explore the effects of three different ventilatory modes: volume controlled ventilation (VCV), pressure controlled ventilation (PCV) and pressure controlled ventilation-volume guaranteed (PCV-VG) on arterial oxygenation and airway pressure during one-lung ventilation (OLV) in elderly patients. Methods: We enrolled 66 patients who underwent thoracic surgery requiring at least 1 hour of OLV and aged above 65 years into the study. Patients were classified into VCV, PCV and PCV-VG groups according to a controlled, randomized design. Patients were ventilated to obtain a tidal volume (TV) of 8 mL/kg with three different ventilatory modes during OLV. The Hemodynamic and respiratory data had been recorded during intraoperation and arterial blood gases were obtained at baseline, 20, 40, 60 minutes after OLV, end of surgery. Results: Compared with VCV group, Ppeak was significantly lower in PCV and PCV-VG group (P<0.05), and the difference was not found between the PCV and PCV-VG group. PaO2 in PCV and PCV-VG group were higher than VCV group after the point of OLV+40 (P<0.05). Comparison of PCV group, PaO2 in PCV-VG group was higher, but did not show a significantly improved during OLV (P>0.05). Conclusions: Compared with VCV, the use of PCV and PCV-VG have a significant advantage in intraoperative oxygenation and airway pressure for eldly patients undergoing OLV. PMID:26309682

  2. Adaptive control of a pressure-controlled artificial ventilator: a simulator-based evaluation using real COPD patient data.

    PubMed

    De Keyser, Robin; Ionescu, Clara

    2011-12-01

    The paper discusses the application of a direct adaptive controller to a pressure controlled artificial ventilation problem. In pressure controlled ventilators, the manipulated variable is the maximum flow applied to the patient during the active phase (inspiration), and the regulated variable is the peak pressure at end-inspiration. This simulation case study focuses on patients diagnosed with Chronic Obstructive Pulmonary Disease (COPD), which require artificial/mechanical ventilation. An adaptive PID controller ensures peak pressures below critical values, by manipulating the flow delivered by the ventilator. The simulation study is performed on fractional-order models of the respiratory impedance identified from lung function data obtained from 21 COPD patients. Additional simulation studies show the robustness of the controller in presence of varying model parameters from the respiratory impedance of the patient. Possibilities to implement the control strategy as an online adaptive algorithm are also explored. The results show that the design of the control is suitable for this kind of application and provides useful insight on realistic scenarios. PMID:21458877

  3. Differential Effects of Endotracheal Suctioning on Gas Exchanges in Patients with Acute Respiratory Failure under Pressure-Controlled and Volume-Controlled Ventilation

    PubMed Central

    Liu, Xiao-Wei; Jin, Yan; Ma, Tao; Qu, Bo; Liu, Zhi

    2015-01-01

    This study was conducted to evaluate the effects of open endotracheal suctioning on gas exchange and respiratory mechanics in ARF patients under the modes of PCV or VCV. Ninety-six ARF patients were treated with open endotracheal suctioning and their variations in respiratory mechanics and gas exchange after the suctions were compared. Under PCV mode, compared with the initial level of tidal volume (VT), ARF patients showed 30.0% and 27.8% decrease at 1?min and 10?min, respectively. Furthermore, the initial respiratory system compliance (Crs) decreased by 29.6% and 28.5% at 1?min and 10?min, respectively. Under VCV mode, compared with the initial level, 38.6% and 37.5% increase in peak airway pressure (PAP) were found at 1?min and 10?min, respectively. Under PCV mode, the initial PaO2 increased by 6.4% and 10.2 % at 3?min and 10?min, respectively, while 18.9% and 30.6% increase of the initial PaO2 were observed under VCV mode. Summarily, endotracheal suctioning may impair gas exchange and decrease lung compliance in ARF patients receiving mechanical ventilation under both PCV and VCV modes, but endotracheal suctioning effects on gas exchange were more severe and longer-lasting under PCV mode than VCV. PMID:25954759

  4. Adaptive Support Ventilation (ASV).

    PubMed

    Brunner, J X; Iotti, G A

    2002-05-01

    Adaptive Support Ventilation is a novel ventilation mode, a closed-loop control mode that may switch automatically from a PCV-like behaviour to an SIMV-like or PSV-like behaviour, according to the patient status. The operating principles are based on pressure-controlled SIMV with pressure levels and SIMV rate automatically adjusted according to measured lung mechanics at each breath. ASV provided a safe and effective ventilation in patients with normal lungs, restrective or obstructive diseases. In cardiac surgery tracheal extrubation was faster in ASV patients then in controls. In the early weaning phase of acute ventilatory insufficiency the need of resetting ventilator parameters was decreased, suggesting potential benefit for patient care. PMID:12029247

  5. Pneumococcal Vaccines (PCV, PPSV)

    MedlinePLUS

    ... With Bullies Pregnant? What to Expect Your Child's Immunizations: Pneumococcal Vaccines (PCV, PPSV) KidsHealth > Parents > General Health > Your Kid's ... but also help stop the infections from spreading. Immunization Schedule PCV13 immunizations are given to all infants ...

  6. Distribution of regional lung aeration and perfusion during conventional and noisy pressure support ventilation in experimental lung injury.

    PubMed

    Carvalho, Alysson R; Spieth, Peter M; Güldner, Andreas; Cuevas, Maximilano; Carvalho, Nadja C; Beda, Alessandro; Spieth, Stephanie; Stroczynski, Christian; Wiedemann, Bärbel; Koch, Thea; Pelosi, Paolo; de Abreu, Marcelo Gama

    2011-04-01

    In acute lung injury (ALI), pressure support ventilation (PSV) may improve oxygenation compared with pressure-controlled ventilation (PCV), and benefit from random variation of pressure support (noisy PSV). We investigated the effects of PCV, PSV, and noisy PSV on gas exchange as well as the distribution of lung aeration and perfusion in 12 pigs with ALI induced by saline lung lavage in supine position. After injury, animals were mechanically ventilated with PCV, PSV, and noisy PSV for 1 h/mode in random sequence. The driving pressure was set to a mean tidal volume of 6 ml/kg and positive end-expiratory pressure to 8 cmH?O in all modes. Functional variables were measured, and the distribution of lung aeration was determined by static and dynamic computed tomography (CT), whereas the distribution of pulmonary blood flow (PBF) was determined by intravenously administered fluorescent microspheres. PSV and noisy PSV improved oxygenation and reduced venous admixture compared with PCV. Mechanical ventilation with PSV and noisy PSV did not decrease nonaerated areas but led to a redistribution of PBF from dorsal to ventral lung regions and reduced tidal reaeration and hyperinflation compared with PCV. Noisy PSV further improved oxygenation and redistributed PBF from caudal to cranial lung regions compared with conventional PSV. We conclude that assisted ventilation with PSV and noisy PSV improves oxygenation compared with PCV through redistribution of PBF from dependent to nondependent zones without lung recruitment. Random variation of pressure support further redistributes PBF and improves oxygenation compared with conventional PSV. PMID:21270348

  7. FISH in polycythemia vera (PCV)

    SciTech Connect

    Amiel, A.; Gaber, E.; Manor, Y.

    1994-09-01

    Trisomies 8 and 9 are the most common numerical abnormalities in polycythemia vera (PCV). However, their role in the pathogenesis of the disease is unclear as is their diagnostic or prognostic value. We evaluated the role of fluorescent in-situ hybridization (FISH) as compared to chromosome analysis in the detection of trisomies 8 or 9 in peripheral blood cells of 14 PCV and 5 secondary PCV patients. Using FISH, we found trisomies 8 and 9 in 10 PCV patients above the cutoff levels of 5%. However, no patient with the secondary PCV reached the cutoff level. Out of 10 PCV patients in whom the trisomy was detected by FISH, only in 3 was this trisomy also detected by routine cytogenetics. The incidence of the finding of trisomy 9 correlates with the duration of the disease, suggesting that this is not the primary event in PCV. FISH is a sensitive, convenient and rapid method for diagnosis and follow-up of chromosome aberrations in PCV patients. Application of FISH to larger cohort of patients may provide valuable information regarding their role in initiation and progession of the disease.

  8. 13-valent pneumococcal conjugate vaccine (PCV13).

    PubMed

    Jefferies, Johanna M C; Macdonald, Emily; Faust, Saul N; Clarke, Stuart C

    2011-10-01

    The thirteen valent pneumococcal conjugate vaccine (PCV13, Prevenar 13(TM)) is the broader coverage successor to the highly effective seven valent vaccine (PCV7, Prevenar(TM)) which has reduced rates of pneumococcal disease in many countries. Despite the success of PCV7, pneumococcal disease due to non-PCV7 serotypes remains a threat in many settings, in particular many developing countries with a high burden of pneumococcal disease where serotype 1 and 5 are among the most common serotypes. Disease due to certain non-PCV7 serotypes, in particular serotype 19A has also begun to increase in incidence in countries with widespread use of PCV7. PCV13 consists of thirteen pneumococcal capsular polysaccharides individually conjugated to the diphtheria-derived protein carrier CRM(197). In addition to serotypes 4, 6B, 9V, 14, 18C, 19F and 23F included in PCV7, PCV13 also includes serotypes 1, 3, 5, 6A, 7F and 19A. PCV13 was licensed on the basis of non-inferiority trials and has proved to be at least as safe and effective as PCV7. PCV13 replaced PCV7 in the childhood immunisation schedules of the USA and UK in 2010 and is being rolled out to an increasing number of developing countries during 2011. Here we review the current literature regarding this vaccine, describing safety, efficacy, global serotype coverage and use and future directions. PMID:21941097

  9. Tracheostomy and mechanical ventilation weaning in children affected by respiratory virus according to a weaning protocol in a pediatric intensive care unit in Argentina: an observational restrospective trial.

    PubMed

    Caprotta, Gustavo; Crotti, Patricia Gonzalez; Frydman, Judith

    2011-01-01

    We describe difficult weaning after prolonged mechanical ventilation in three tracheostomized children affected by respiratory virus infection. Although the spontaneous breathing trials were successful, the patients failed all extubations. Therefore a tracheostomy was performed and the weaning plan was begun. The strategy for weaning was the decrease of ventilation support combining pressure control ventilation (PCV) with increasing periods of continuous positive airway pressure + pressure support ventilation (CPAP + PSV) and then CPAP + PSV with increasing intervals of T-piece. They presented acute respiratory distress syndrome on admission with high requirements of mechanical ventilation (MV). Intervening factors in the capabilities and loads of the respiratory system were considered and optimized. The average MV time was 69 days and weaning time 31 days.We report satisfactory results within the context of a directed weaning protocol. PMID:21244710

  10. Pathogenesis of PCV2a and PCV2b virus in germ-free pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic analysis of porcine circovirus type 2 (PCV2) reveals 2 subgroups that will be referred to as PCV2a and PCV2b representing the North American and European prototypes respectfully. This paper summarizes 3 studies comparing the pathogenesis of 2a and 2b viruses in germ-free pigs. In this PCV2...

  11. Ventilation.

    PubMed

    Turner, W A; Bearg, D W; Brennan, T

    1995-01-01

    This chapter begins with an overview of the history of ventilation guidelines, which has led to the guidelines that are in effect today. Of particular interest is the most recent return in the past 5 years to ventilation rates that more closely reflect a mean or average of the range of guidelines that have existed over the past century. OSHA's and the EPA's recognition of the need to operate ventilation systems in buildings in an accountable manner is also of note. Of even more interest is the resurgence of the concept of minimum mixing and once-through ventilation air that has been pursued in parts of Northern Europe for the past 10 years, and in a school that is being designed with this concept in New Hampshire. In addition, the design concept of equipping office buildings with low pressure drop high efficiency particle filtration to remove fine particles from all of the air that is supplied to the occupants is being used increasingly in the U.S. This chapter also presents an overview of the various types of ventilation systems found in homes and commercial office buildings and the common indoor air quality problems that may be associated with them. It also offers an overview of common HVAC evaluation techniques that can be used to determine if a ventilation system is performing in a manner that makes sense for the use of the space and the needs of the occupants. Are the occupants receiving a reasonable supply of outdoor air? Is the air that they receive of reasonable quality? Are obvious pollutants being exhausted? Ventilation systems have become extremely complex and more difficult to run and maintain over the past 40 years. This trend will continue to drive the need for professionally maintained HVAC equipment that is serviced and run by individuals who are accountable for the quality of the air that the system delivers. PMID:7792680

  12. Impact of Ventilatory Modes on the Breathing Variability in Mechanically Ventilated Infants

    PubMed Central

    Baudin, Florent; Wu, Hau-Tieng; Bordessoule, Alice; Beck, Jennifer; Jouvet, Philippe; Frasch, Martin G.; Emeriaud, Guillaume

    2014-01-01

    Objectives: Reduction of breathing variability is associated with adverse outcome. During mechanical ventilation, the variability of ventilatory pressure is dependent on the ventilatory mode. During neurally adjusted ventilatory assist (NAVA), the support is proportional to electrical activity of the diaphragm (EAdi), which reflects the respiratory center output. The variability of EAdi is, therefore, translated into a similar variability in pressures. Contrastingly, conventional ventilatory modes deliver less variable pressures. The impact of the mode on the patient’s own respiratory drive is less clear. This study aims to compare the impact of NAVA, pressure-controlled ventilation (PCV), and pressure support ventilation (PSV) on the respiratory drive patterns in infants. We hypothesized that on NAVA, EAdi variability resembles most of the endogenous respiratory drive pattern seen in a control group. Methods: Electrical activity of the diaphragm was continuously recorded in 10 infants ventilated successively on NAVA (5?h), PCV (30?min), and PSV (30?min). During the last 10?min of each period, the EAdi variability pattern was assessed using non-rhythmic to rhythmic (NRR) index. These variability profiles were compared to the pattern of a control group of 11 spontaneously breathing and non-intubated infants. Results: In control infants, NRR was higher as compared to mechanically ventilated infants (p?PCV. PSV exhibited an intermediary pattern. Perspectives: Mechanical ventilation impacts the breathing variability in infants. NAVA produces EAdi pattern resembling most that of control infants. NRR can be used to characterize respiratory variability in infants. Larger prospective studies are necessary to understand the differential impact of the ventilatory modes on the cardio-respiratory variability and to study their impact on clinical outcomes. PMID:25505779

  13. Porcine circovirus type 2 (PCV2) vaccination is effective in reducing disease and PCV2 shedding in semen of boars concurrently infected with PCV2 and Mycoplasma hyopneumoniae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objectives of this study were to determine if the amount of porcine circovirus type 2 (PCV2) shed in semen will be increased in boars experimentally coinfected with Mycoplasma hyopneumoniae (MHYO) and if PCV2 vaccination of the boars prior to PCV2 exposure will result in reduced PCV2 viremia and...

  14. Chronic blood pressure control.

    PubMed

    Brands, Michael W

    2012-10-01

    Chronic blood pressure is maintained within very narrow limits around an average value. However, the multitude of physiologic processes that participate in blood pressure control present a bewildering array of possibilities to explain how such tight control of arterial pressure is achieved. Guyton and Coleman and colleagues addressed this challenge by creating a mathematical model that integrated the short- and long-term control systems for overall regulation of the circulation. The hub is the renal-body fluid feedback control system, which links cardiac function and vascular resistance and capacitance with fluid volume homeostasis as the foundation for chronic blood pressure control. The cornerstone of that system is renal sodium excretory capability, which is defined by the direct effect of blood pressure on urinary sodium excretion, that is, "pressure natriuresis." Steady-state blood pressure is the pressure at which pressure natriuresis balances sodium intake over time; therefore, renal sodium excretory capability is the set point for chronic blood pressure. However, this often is misinterpreted as dismissing, or minimizing, the importance of nonrenal mechanisms in chronic blood pressure control. This article explains the renal basis for the blood pressure set point by focusing on the absolute dependence of our survival on the maintenance of sodium balance. Two principal threats to sodium balance are discussed: (1) a change in sodium intake or renal excretory capability and (2) a change in blood pressure. In both instances, circulatory homeostasis is maintained because the sodium balance blood pressure set point is reached. PMID:23720255

  15. Singular PCV2a or PCV2b infection results in apoptosis of hepatocytes in clinically affected gnotobiotic pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Porcine circovirus type 2 (PCV2) which can be further subdivide into two main genotypes, PCV2a and PCV2b, is often clinically associated with respiratory signs, failure-to-thrive, and diarrhea. The precise pathogenesis of PCV2, and in particular its involvement in apoptosis, is controversial. The ob...

  16. Blood Pressure Control

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Engineering Development Laboratory developed a system for the cardiovascular study of weightless astronauts. This was designed to aid people with congestive heart failure and diabetes. While in space, astronauts' blood pressure rises, heart rate becomes unstable, and there are sometimes postflight lightheadedness or blackouts. The Baro-Cuff studies the resetting of blood pressure. When a silicone rubber chamber is strapped to the neck, the Baro-Cuff stimulates the carotid arteries by electronically controlled pressure application. Blood pressure controls in patients may be studied.

  17. Mutant USA strain of porcine circovirus type 2 (mPCV2) exhibits similar virulence to the classical PCV2a and PCV2b strains in caesarean-derived, colostrum-deprived pigs

    PubMed Central

    Xiao, Chao-Ting; Gerber, Priscilla F.; Halbur, Patrick G.; Matzinger, Shannon R.; Meng, Xiang-Jin

    2014-01-01

    In 2012, a mutant porcine circovirus type 2 (mPCV2) strain was identified in cases of PCV-associated disease (PCVAD) in the USA. The mPCV2 had an additional amino acid, lysine (K), in the capsid at position 234. The objectives of this study were to compare the pathogenicity of mPCV2, PCV2a and PCV2b in pigs using biologically pure infectious virus stocks derived from respective infectious DNA clones, and to investigate the importance of genotype-specific ORF2 and the presence of lysine at position 234 of the capsid. A total of 47, 2-week-old, caesarean-derived, colostrum-deprived (CDCD) pigs were assigned to one of seven groups. At 3 weeks of age, the pigs were experimentally inoculated with saline, PCV2a, PCV2b, mPCV2, PCV2b-234-K (lysine addition in ORF2), chimeric PCV2b-ORF1/mPCV2-ORF2 or reciprocal chimeric mPCV2-ORF1/PCV2b-ORF2. All pigs were necropsied 21 days post-infection (p.i.). Gross lesions were limited to visible icterus and loss of body condition in a portion of the mPCV2 pigs. The amount of PCV2 DNA was significantly higher in pigs inoculated with mPCV2 compared with PCV2b in sera at 7 days p.i. and faecal swabs at 14 days p.i. Based on lymphoid lesions, a higher prevalence of PCVAD was seen in pigs infected with PCV2s containing the additional 234-K (64.3?%) compared with those infected with a PCV2 with the regular 233 bp ORF2 (40?%). Results indicated that all PCV2 isolates were capable of inducing severe lesions and disease in the CDCD pig model, and there was no significant difference in virulence. PMID:25053562

  18. Comparative Effects of Vaccination against Porcine Circovirus Type 2 (PCV2) and Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) in a PCV2-PRRSV Challenge Model

    PubMed Central

    Park, Changhoon; Oh, Yeonsu; Seo, Hwi Won; Han, Kiwon

    2013-01-01

    The objective of the present study was to determine the effects of porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV) vaccinations in an experimental PCV2-PRRSV challenge model, based on virological (viremia), immunological (neutralizing antibodies [NAs], gamma interferon-secreting cells [IFN-?-SCs], and CD4+ CD8+ double-positive cells), and pathological (lesions and antigens in lymph nodes and lungs) evaluations. A total of 72 pigs were randomly divided into 9 groups (8 pigs per group): 5 vaccinated and challenged groups, 3 nonvaccinated and challenged groups, and a negative-control group. Vaccination against PCV2 induced immunological responses (NAs and PCV2-specific IFN-?-SCs) and reduced PCV2 viremia, PCV2-induced lesions, and PCV2 antigens in the dually infected pigs. However, vaccination against PCV2 did not affect the PRRSV immunological responses (NAs and PRRSV-specific IFN-?-SCs), PRRSV viremia, PRRSV-induced lesions, or PRRSV antigens in the dually infected pigs. Vaccination against PRRSV did not induce immunological responses (PRRSV-specific IFN-?-SCs) or reduce PRRSV viremia, PRRSV-induced lesions, or PRRSV antigens in the dually infected pigs. In addition, vaccination against PRRSV increased PCV2 viremia, PCV2-induced lesions, and PCV2 antigens in the dually infected pigs. In summary, vaccination against PCV2 reduced PCV2 viremia, PCV2-induced lesions, and PCV2 antigens in the dually infected pigs. However, vaccination against PRRSV increased PCV2 viremia, PCV2-induced lesions, and PCV2 antigens in the dually infected pigs. Therefore, the PCV2 vaccine decreased the potentiation of PCV2-induced lesions by PRRSV in dually infected pigs. In contrast, the PRRSV vaccine alone did not decrease the potentiation of PCV2-induced lesions by PRRSV in dually infected pigs. PMID:23302743

  19. Influence of Maternal Antibodies on Efficacy of Porcine Circovirus Type 2 (PCV2) Vaccination To Protect Pigs from Experimental Infection with PCV2?

    PubMed Central

    Opriessnig, T.; Patterson, A. R.; Elsener, J.; Meng, X. J.; Halbur, P. G.

    2008-01-01

    Due to the ubiquitous nature of porcine circovirus type 2 (PCV2) in the pig population and the increasing use of PCV2 vaccines in breeding herds, the majority of dams have been exposed to field PCV2 or PCV2 vaccines, resulting in piglets with varied levels of passively acquired PCV2 maternal antibodies. The objective of the current research was to investigate the influence of passively acquired anti-PCV2 antibodies on PCV2 vaccine efficacy. Sixty 26-day-old pigs were divided into four groups: vaccinated pigs with no maternal PCV2 antibodies at the time of vaccination (VAC-NEG; n = 9), vaccinated pigs with maternal PCV2 antibodies at the time of vaccination (VAC-POS; n = 21), nonvaccinated pigs with no maternal antibodies at the time of challenge (NVAC-CNEG; n = 15), and nonvaccinated pigs with maternal antibodies at the time of challenge (NVAC-CPOS; n = 15). Vaccinations and challenges were performed on trial days 0 and 28, respectively, according to group designation. The pigs were monitored for clinical signs of disease daily and weighed weekly, and blood was collected weekly. All pigs were necropsied on trial day 49, and tissues were evaluated for macroscopic and microscopic lesions. Serum was evaluated using PCV2 immunoglobulin G (IgG) and PCV2 IgM enzyme-linked immunosorbent assays, quantitative PCV2 PCR, and a serum PCV2 neutralizing antibody test. In comparison to NVAC-CPOS pigs, VAC-POS animals had significantly (P < 0.01) less severe microscopic PCV2-associated lymphoid lesions and significantly (P < 0.04) reduced PCV2 genomic copies in serum following PCV2 challenge. These results indicate that vaccination with Suvaxyn PCV2 One Dose reduces viremia and prevents microscopic lesions associated with PCV2 in the presence of maternal antibodies. PMID:18094109

  20. Controller modeling and evaluation for PCV electro-mechanical actuator

    NASA Technical Reports Server (NTRS)

    Parker, Joey K.

    1993-01-01

    Hydraulic actuators are currently used to operate the propellant control valves (PCV) for the space shuttle main engine (SSME) and other rocket engines. These actuators are characterized by large power to weight ratios, large force capabilities, and rapid accelerations, which favor their use in control valve applications. However, hydraulic systems are also characterized by susceptibility to contamination, which leads to frequent maintenance requirements. The Control Mechanisms Branch (EP34) of the Component Development Division of the Propulsion Laboratory at the Marshall Space Flight Center (MSFC) has been investigating the application of electromechanical actuators as replacements for the hydraulic units in PCV's over the last few years. This report deals with some testing and analysis of a PCV electromechanical actuator (EMA) designed and fabricated by HR Textron, Inc. This prototype actuator has undergone extensive testing by EP34 personnel since early 1993. At this time, the performance of the HR Textron PCV EMA does not meet requirements for position tracking.

  1. Pigs naturally exposed to porcine circovirus type 2 (PCV2) generate antibody responses capable to neutralise PCV2 isolates of different genotypes and geographic origins

    PubMed Central

    2014-01-01

    Porcine circovirus type 2 (PCV2) is the essential infectious agent for PCV2-systemic disease (PCV2-SD, formerly known as postweaning multisystemic wasting syndrome) and other pathological conditions. Recent studies indicated antigenic variability amongst different PCV2 isolates and suggested that single amino acid changes within the capsid protein determine differences in the level of neutralization by specific monoclonal antibodies. The objective of the present study was to examine the cross-reactivity of PCV2 antibodies induced in the context of a natural infection against different PCV2 isolates belonging to genotypes PCV2a and PCV2b. Sera taken from several farms from animals of varying health status (PCV2-SD and age-matched healthy pigs and a set of slaughter-aged animals) were assayed for neutralizing activity against four PCV2 isolates from both predominant genotypes (PCV2a and PCV2b) and of differing geographic origins (Europe and North-America). Results showed that most of studied pigs (79 out of 82) contained neutralizing antibodies (NA) able to neutralize all four studied viral strains. Overall, pigs had significantly higher NA titres against PCV2a than against PCV2b (P?PCV2a) than L-33-Sp-10-54 and MO/S-06 strains (PCV2b) (P?PCV2 isolates translate to functional antigenic differences in viral neutralization in vivo. PMID:24602200

  2. Effects of an Inactivated Porcine Circovirus Type 2 (PCV2) Vaccine on PCV2 Virus Shedding in Semen from Experimentally Infected Boars ?

    PubMed Central

    Seo, Hwi Won; Han, Kiwon; Kim, Duyeol; Oh, Yeonsu; Kang, Ikjae; Park, Changhoon; Jang, Hyun; Chae, Chanhee

    2011-01-01

    The objective of the present study was to determine the effect of an inactivated porcine circovirus type 2 (PCV2) vaccine on PCV2b virus shedding in the semen of experimentally infected boars by measuring the immunological response and the PCV2b DNA load in blood and semen. Twelve boars were randomly divided into three groups. The boars in group 1 (n = 4) were immunized with an inactivated PCV2 vaccine and were challenged with PCV2b. The boars in group 2 (n = 4) were only challenged with PCV2b. The boars in group 3 (n = 4) served as negative controls. The number of PCV2 genome copies of PCV2 in the serum and semen were significantly lower in vaccinated challenged boars than in nonvaccinated challenged boars at 7, 10, 14, 21, 32, 35, 42, 49, and 60 days postinoculation. The number of PCV2b genomes in the semen correlated with the number of PCV2b genomes in the blood in both vaccinated challenged (R = 0.714) and nonvaccinated challenged (R = 0.861) boars. The results of the present study demonstrate that the inactivated PCV2 vaccine significantly decreases the amount of PCV2b DNA shedding in semen from vaccinated boars after experimental infection with PCV2b. PMID:21613465

  3. EFFECT OF PORCINE CIRCOVIRUS TYPE 2 (PCV2) VACCINATION ON PORCINE REPRODUCTIVE AND RESPIRATORY SYNDROME VIRUS (PRRSV) AND PCV2 COINFECTION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objectives of this study were (1) to determine if PCV2 vaccination is effective in reducing disease and lesions associated with PRRSV and PCV2 coinfection and (2) to determine if there is a difference between intradermal (ID) and intramuscular (IM) route of PCV2 vaccination. Seventy-four, 21 day...

  4. Ventilation and ventilators.

    PubMed

    Hayes, B

    1982-01-01

    The history of ventilation is reviewed briefly and recent developments in techniques of ventilation are discussed. Operating features of ventilators have changed in the past few years, partly as the result of clinical progress; yet, technology appears to have outstripped the clinician's ability to harness it most effectively. Clinical discipline and training of medical staff in the use of ventilators could be improved. The future is promising if clinician and designer can work together closely. Ergonomics of ventilators and their controls and the provision of alarms need special attention. Microprocessors are likely to feature prominently in the next generation of designs. PMID:6754938

  5. Modified Indirect Porcine Circovirus (PCV) Type 2-Based and Recombinant Capsid Protein (ORF2)-Based Enzyme-Linked Immunosorbent Assays for Detection of Antibodies to PCV

    PubMed Central

    Nawagitgul, Porntippa; Harms, Perry A.; Morozov, Igor; Thacker, Brad J.; Sorden, Steven D.; Lekcharoensuk, Chalermpol; Paul, Prem S.

    2002-01-01

    Postweaning multisystemic wasting syndrome of swine associated with porcine circovirus (PCV) is a recently reported and economically important disease. Simple and reliable diagnostic methods are needed for detecting antibodies to PCV type 2 (PCV2) for monitoring of PCV infection. Here, we report the development of two modified indirect enzyme-linked immunosorbent assays (ELISAs): a PCV2 ELISA based on cell-culture-propagated PCV2 and an ORF2 ELISA based on recombinant major capsid protein. PCV2 and ORF2 ELISA detected antibodies to PCV2 and the capsid protein, respectively, in sera from pigs experimentally infected with PCV2 as early as 14 and 21 days postinoculation (dpi). The kinetics of the antibody response to PCV2 and the major capsid protein were similar. Repeatability tests revealed that the coefficients of variation of positive sera within and between runs for both assays were less than 30%. To validate the assays, PCV2 and ORF2 ELISAs were performed with 783 serum samples of young and adult pigs collected from different herds in the Midwestern United States and compared with an indirect immunofluorescent assay (IIF). Six out of 60 samples collected from nursery and growing pigs in 1987 were positive by both ELISA and IIF. Compared with IIF, the diagnostic sensitivity, specificity, and accuracy of PCV2 and ORF2 ELISAs were similar (>90%). The tests showed no cross-reactivity with antibodies to porcine parvovirus and porcine reproductive and respiratory syndrome virus. There was good agreement between the two ELISAs and between the ELISAs and IIF. The availability of the two ELISAs should accelerate our understanding of the host immune response to PCV2 and facilitate the development of prevention and control strategies by elucidating the ecology of PCV2 within swine populations. PMID:11777826

  6. Genetic characterisation of Porcine circovirus type 2 (PCV2) strains from feral pigs in the Brazilian Pantanal: An opportunity to reconstruct the history of PCV2 evolution.

    PubMed

    Franzo, Giovanni; Cortey, Martí; de Castro, Alessandra Marnie Martins Gomes; Piovezan, Ubiratan; Szabo, Matias Pablo Juan; Drigo, Michele; Segalés, Joaquim; Richtzenhain, Leonardo José

    2015-07-01

    Since its discovery, Porcine circovirus type 2 has emerged as one of the most relevant swine infectious diseases, causing relevant economic losses for the pig industry. While four genotypes were identified, only three (PCV2a, PCV2b and PCV2d) are currently circulating and display a worldwide distribution. Another genotype, PCV2c, has been described only once in Danish archive samples collected between 1980 and 1990. In addition to commercial pigs, PCV2 has been demonstrated to infect wild boars and other wild species, which can potentially serve as a reservoir for domestic populations. In this study, eight sequences obtained from feral pigs in the Pantanal region (Mato Grosso do Sul State, Brazil) were compared with reference sequences and other Brazilian sequences, and the results revealed remarkable genetic diversity, with all four genotypes currently recognised being detected (PCV2a, PCV2b, PCV2c and PCV2d). This finding represents a remarkable discovery, as it is the first detection of PCV2c since 1990 and the first-ever detection of PCV2c in live animals. The peculiar population history and ecological scenario of feral pigs in the Pantanal coupled with the complex, and still only partially known relationship of feral pigs with other PCV2 susceptible species (i.e., domestic pigs, wild boars and peccaries), open exciting questions concerning PCV2 origin and evolution. Overall, the results of the present study led us to form the following hypothesis: the PCV2 strains found in feral pigs may be the last descent of the strains that circulated among European pigs in the past, or they may have infected these feral pigs more recently through a bridge species. PMID:25975522

  7. Adaptive lung ventilation.

    PubMed

    Linton, D M

    2001-09-01

    Adaptive lung ventilation (ALV) is a method of closed-loop mechanical ventilation analogous to modern closed-loop technology in aviation such as the autopilot and automatic landing system. The algorithm of the controller of ALV is designed to automatically provide pressure-controlled synchronized intermittent mandatory ventilation (P-SIMV) and weaning as individually required in any clinical situation. The synchronized pressure limited breaths constantly adapt to the patient requirements to encourage optimal alveolar ventilation with minimal adverse physiological disturbance and timely weaning. The ease of application, efficiency, and safety of the first ALV controllers have been demonstrated in lung models, in patients with normal lungs undergoing general anesthesia, in patients requiring unusual positioning, in transition to and from one-lung anesthesia, and in long-term ventilation of patients with various lung pathologies and in weaning patients who have restrictive or obstructive pulmonary disease. Prospective comparative studies of ALV versus other currently used manually selected modes of mechanical ventilation, such as the one reported in this article, should confirm the safety and identify the benefits of this form of advanced closed-loop mechanical ventilation technology. PMID:11517031

  8. Five winters of pneumococcal serotype replacement in UK carriage following PCV introduction

    PubMed Central

    Gladstone, Rebecca A.; Jefferies, Johanna M.; Tocheva, Anna S.; Beard, Kate R.; Garley, David; Chong, Wei Wei; Bentley, Stephen D.; Faust, Saul N.; Clarke, Stuart C.

    2015-01-01

    The seven-valent pneumococcal conjugate vaccine (PCV7) was added to the UK national immunisation programme in September 2006. PCV13 replaced PCV7 in April 2010. As carriage precedes disease cases this study collected carried pneumococci from children each winter from 2006/7 to 2010/11 over PCV introduction. Conventional microbiology and whole genome sequencing were utilised to characterise pneumococcal strains. Overall prevalence of pneumococcal carriage remained stable. Vaccine serotypes (VT) decreased (p < 0.0001) with concomitant increases in non-vaccine serotypes (NVT). In winter 2010/11 only one isolate of PCV7 VT was observed (6B). PCV13 unique VTs decreased between winters immediately preceding and following PCV13 introduction (p = 0.04). Significant decreases for VTs 6B, 19F, 23F (PCV7) and 6A (PCV13) and increases for NVT 21, 23B, 33F and 35F were detected. The serotype replacement was accompanied by parallel changes in genotype prevalence for associated sequence types with clonal expansion contributing to replacement. By winter 2010/11, serotype coverage of PCV7 and PCV13 was 1% and 11% respectively. VT replacement was observed for PCV7 and PCV13 serotypes. Conjugate vaccine design and use requires continuous monitoring and revision. PMID:25776920

  9. Epidemiology and horizontal transmission of porcine circovirus type 2 (PCV2).

    PubMed

    Patterson, A R; Opriessnig, T

    2010-12-01

    Porcine circovirus type 2 (PCV2) is a small, non-enveloped, circular, single-stranded DNA virus of economic importance in the swine industry worldwide. Based on the sequence analyses of PCV2 strains, isolates can be divided into five subtypes (PCV2a-e). PCV2 is an ubiquitous virus based on serological and viremia data from countries worldwide. In addition, PCV2 DNA was discovered in archived samples prior to the first recognition of clinical disease. Recently, a worldwide shift in PCV2 subtype from PCV2a to PCV2b occurred. PCV2 DNA can be detected in fecal, nasal, oral and tonsillar swabs as well as in urine and feces from both naturally and experimentally infected pigs. PCV2 DNA can be detected early in the infectious process and persists for extended periods of time. The effectiveness of disinfectants for reducing PCV2 in vitro is variable and PCV2 is very stable in the pig environment. Limited data exist on the horizontal transmission of PCV2. Direct transmission of PCV2 between experimentally or naturally infected animals and naïve animals has been documented and the incorporation of clinical or subclinically infected animals into a population represents a risk to the herd. Indirect transmission through the oral, aerosol or vaccine routes is likely a lesser risk for the transmission of PCV2 in most swine populations but may be worth evaluating in high heath herds. The objective of this review was to discuss data on the epidemiology and horizontal transmission of PCV2. PMID:21087576

  10. Modification of PCV-2 virulence by substitution of the genogroup motif of the capsid protein.

    PubMed

    Allemandou, Aude; Grasland, Béatrice; Hernandez-Nignol, Anne-Cécile; Kéranflec'h, André; Cariolet, Roland; Jestin, André

    2011-01-01

    Porcine circovirus type 2 (PCV-2) is the causal agent of the post-weaning multisystemic wasting syndrome (PMWS). PCV-2 are small single-stranded circular DNA viruses clustered into two main genogroups: PCV-2a and PCV-2b. Each genogroup present a specific highly-conserved motif of six amino acids (between amino acids 86 and 91) in the PCV-2 capsid protein. The aim of this study was to verify whether the motif located in the capsid protein and specific to each PCV-2 genogroup contributes to virulence. Two parental DNA clones, PCV-2a and PCV-2b, were constructed as well as two mutants DNA clones, PCV-2a/motif 2b and PCV-2b/motif 2a by exchanging the capsid motif of each genogroup. The four DNA clones were characterized in vitro as well as in vivo. Cells transfected by the four DNA clones produced infectious viruses. In specific-pathogen-free piglets transfected by the four infectious DNA clones, PCV-2b/motif 2a virulence was not attenuated while the PCV-2a/motif 2b virulence was drastically reduced compared to their parent virulence. These results suggest that the amino acids between positions 86 and 91 of the capsid protein are determinant for the virulence of isolates. However, the environment of this motif seems also involved. PMID:21435235

  11. Building pressurization control with rooftop air conditioners

    SciTech Connect

    Winter, S.

    1982-10-01

    The modulated exhaust fan appears to be the most cost effective positive means to maintain close building pressure control with rooftop air conditioning, but because building construction and applications vary, every building's pressure control needs must be analyzed. Requirements will vary from no relief to barometric dampers to return fans to modulated exhaust fans. As heating and cooling costs continue to rise and tighter building codes prevail, proper selection of building pressure control is one area that must be monitored more carefully by the HVAC system designer.

  12. Using ventilator graphics to identify patient-ventilator asynchrony.

    PubMed

    Nilsestuen, Jon O; Hargett, Kenneth D

    2005-02-01

    Patient-ventilator interaction can be described as the relationship between 2 respiratory pumps: (1) the patient's pulmonary system, which is controlled by the neuromuscular system and influenced by the mechanical characteristics of the lungs and thorax, and (2) the ventilator, which is controlled by the ventilator settings and the function of the flow valve. When the 2 pumps function in synchrony, every phase of the breath is perfectly matched. Anything that upsets the harmony between the 2 pumps results in asynchrony and causes patient discomfort and unnecessarily increases work of breathing. This article discusses asynchrony relative to the 4 phases of a breath and illustrates how asynchrony can be identified with the 3 standard ventilator waveforms: pressure, flow, and volume. The 4 phases of a breath are: (1) The trigger mechanism (ie, initiation of the inspiration), which is influenced by the trigger-sensitivity setting, patient effort, and valve responsiveness. (2) The inspiratory-flow phase. During both volume-controlled and pressure-controlled ventilation the patient's flow demand should be carefully evaluated, using the pressure and flow waveforms. (3) Breath termination (ie, the end of the inspiration). Ideally, the ventilator terminates inspiratory flow in synchrony with the patient's neural timing, but frequently the ventilator terminates inspiration either early or late, relative to the patient's neural timing. During volume-controlled ventilation we can adjust variables that affect inspiratory time (eg, peak flow, tidal volume). During pressure-controlled or pressure-support ventilation we can adjust variables that affect when the inspiration terminates (eg, inspiratory time, expiratory sensitivity). (4) Expiratory phase. Patients with obstructive lung disease are particularly prone to developing intrinsic positive end-expiratory pressure (auto-PEEP) and therefore have difficulty triggering the ventilator. Bedside evaluation for the presence of auto-PEEP should be routinely performed and corrective adjustments made when appropriate. PMID:15691392

  13. Survival following adjuvant PCV or temozolomide for anaplastic astrocytoma

    PubMed Central

    Brandes, Alba A.; Nicolardi, Linda; Tosoni, Alicia; Gardiman, Marina; Iuzzolino, Paolo; Ghimenton, Claudio; Reni, Michele; Rotilio, Antonino; Sotti, Guido; Ermani, Mario

    2006-01-01

    We compared survival in patients with anaplastic astrocytoma (AA) treated with adjuvant procarbazine, lomustine, and vincristine (PCV) with survival in patients treated with temozolomide. A retrospective analysis was made of patients with newly diagnosed AA treated with adjuvant postradiotherapy chemotherapy. Outcome analysis included progression-free survival and overall survival. The following prognostic factors were taken into account: patient age, extent of resection, performance status, presence of contrast enhancement in pre-surgical imaging, and type of adjuvant treatment. Among 109 AA patients, 49 were treated with PCV and 60 with temozolomide. The treatment groups were well matched for pretreatment characteristics, except for the presence of contrast enhancement. Age, extent of surgery, performance status, and presence of contrast enhancement were statistically significant prognostic factors according to the Cox model analysis of survival. Type of adjuvant chemotherapy was not a significant factor, either for progression-free survival or for overall survival. Hematological toxicity, nonhematological toxicity grades 3–4, and premature discontinuation due to toxicity were observed in 9%, 3% to 5%, and 37%, respectively, of cases in the PCV group versus 4% to 5%, 0, and 0, respectively, in the temozolomide group. Although the present study was not randomized, it was well designed, and it reports on two homogeneous and consecutive series of patients, for whom histology was verified to obtain survival data only for patients with AA following the recent WHO 2000 classification. Even if no survival advantage has been demonstrated for temozolomide versus PCV, we conclude that temozolomide should be preferred because of its greater tolerability. PMID:16723632

  14. Survival following adjuvant PCV or temozolomide for anaplastic astrocytoma.

    PubMed

    Brandes, Alba A; Nicolardi, Linda; Tosoni, Alicia; Gardiman, Marina; Iuzzolino, Paolo; Ghimenton, Claudio; Reni, Michele; Rotilio, Antonino; Sotti, Guido; Ermani, Mario

    2006-07-01

    We compared survival in patients with anaplastic astrocytoma (AA) treated with adjuvant procarbazine, lomustine, and vincristine (PCV) with survival in patients treated with temozolomide. A retrospective analysis was made of patients with newly diagnosed AA treated with adjuvant postradiotherapy chemotherapy. Outcome analysis included progression-free survival and overall survival. The following prognostic factors were taken into account: patient age, extent of resection, performance status, presence of contrast enhancement in presurgical imaging, and type of adjuvant treatment. Among 109 AA patients, 49 were treated with PCV and 60 with temozolomide. The treatment groups were well matched for pretreatment characteristics, except for the presence of contrast enhancement. Age, extent of surgery, performance status, and presence of contrast enhancement were statistically significant prognostic factors according to the Cox model analysis of survival. Type of adjuvant chemotherapy was not a significant factor, either for progression-free survival or for overall survival. Hematological toxicity, nonhematological toxicity grades 3-4, and premature discontinuation due to toxicity were observed in 9%, 3% to 5%, and 37%, respectively, of cases in the PCV group versus 4% to 5%, 0, and 0, respectively, in the temozolomide group. Although the present study was not randomized, it was well designed, and it reports on two homogeneous and consecutive series of patients, for whom histology was verified to obtain survival data only for patients with AA following the recent WHO 2000 classification. Even if no survival advantage has been demonstrated for temozolomide versus PCV, we conclude that temozolomide should be preferred because of its greater tolerability. PMID:16723632

  15. The effect of head rotation on efficiency of ventilation and cuff pressure using the PLMA in pediatric patients

    PubMed Central

    Park, Hahck Soo; Kim, Youn Jin

    2011-01-01

    Background This study examined whether changing the head position from neutral to side can affect expiratory tidal volume (TV) and cuff pressure when the appropriate sizes of a Proseal™ Laryngeal Mask Airway (PLMA)-depending on the body weight -are used in pediatric patients during pressure controlled ventilation (PCV). Methods Seventy-seven children (5-30 kg) were divided into three groups according to their body weight, PLMA#1.5 (group I, n = 24), #2 (group II, n = 26), and #2.5 (group III, n = 27). After anesthesia induction, a PLMA was placed with a cuff-pressure of 60 cmH2O. The TV and existence of leakage at the peak inspiratory pressure (PIP) of 20 cmH2O, and the appropriate PIP for TV 10 ml/kg were examined. Upon head rotation to the left side, the TV, PIP, cuff pressure changes, and the appropriate PIP to achieve a TV 10 ml/kg were evaluated. Results Head rotation of 45 degrees to the left side during PCV caused a significant increase in cuff pressure and a decrease in TV, and there was no definite leakage. Changes in PIP and TV were similar in the three groups. The cuff pressure increased but there was no significant difference between the three groups. Conclusions Although cuff pressure and TV of the PLMA were changed significantly after turning the head from the neutral position to the side, a re-adjustment of the cuff pressure and PIP to maintain a TV of 10 ml/kg can make the placed PLMA useful and successful in pediatric patients under general anesthesia. PMID:22025944

  16. Comparison of Porcine circovirus type 2 (PCV2) infection in light and heavy pigs of market age on farms with routine PCV2 vaccination.

    PubMed

    Lyoo, Kwang-Soo; Joo, Han Soo; Davies, Peter R; Han, Jeong Hee

    2012-07-01

    Commercial vaccines against Porcine circovirus type 2 (PCV2) are widely used on swine farms. Marked body weight variation at marketing age is a problem on conventional pig farms using all-in/all-out barn management. The aim of this study was to investigate whether PCV2 infection could be a factor influencing body weight variation. Seven conventional farms that routinely used PCV2 vaccination were selected, and 60 serum samples from light and heavy pigs at each site were tested for PCV2 antibody titers and viremia. At 3 farms the mean antibody titer, proportion of viremic pigs, and virus load differed significantly between the light and heavy groups. These preliminary results suggest that PCV2 infection may be a factor contributing to weight variation in vaccinated market-age hogs. PMID:23277702

  17. A live-attenuated and an inactivated chimeric porcine circovirus (PCV)1-2 vaccine are both effective at inducing a humoral immune response and reducing PCV2 viremia and intrauterine infection in female swine of breeding age

    PubMed Central

    Hemann, Michelle; Beach, Nathan M.; Meng, Xiang-Jin; Wang, Chong; Halbur, Patrick G.; Opriessnig, Tanja

    2014-01-01

    The objective of this pilot study was to determine the efficacy of inactivated (1 or 2 dose) and live-attenuated chimeric porcine circovirus (PCV)1-2 vaccines in sows using the PCV2-spiked semen model. Thirty-five sows were randomly divided into 6 groups: negative and positive controls, 1 dose inactivated PCV1-2 vaccine challenged (1-VAC-PCV2), 2 dose inactivated PCV1-2 vaccine challenged (2-VAC-PCV2), 1 dose live-attenuated PCV1-2 vaccine unchallenged (1-LIVE-VAC), and 1 dose live-attenuated PCV1-2 vaccine challenged (1-LIVE-VAC-PCV2). The inactivated PCV1-2 vaccine induced higher levels of PCV2-specific antibodies in dams. All vaccination strategies provided good protection against PCV2 viremia in dams, whereas the majority of the unvaccinated sows were viremic. Four of the 35 dams became pregnant: a negative control, a positive control, a 2-VAC-PCV2 sow, and a 1-LIVE-VAC-PCV2 sow. The PCV2 DNA was detected in 100%, 67%, and 29% of the fetuses obtained from the positive control, inactivated vaccinated, or live-attenuated vaccinated dams, respectively. The PCV2 antigen in hearts was only detectable in the positive control litter (23% of the fetuses). The PCV1-2 DNA was detected in 29% of the fetuses in the litter from the 1-LIVE-VAC-PCV2 dam. Under the conditions of this pilot study, both vaccines protected against PCV2 viremia in breeding age animals; however, vertical transmission was not prevented. PMID:24396175

  18. Genetic and phylogenetic analysis of a new porcine circovirus type 2 (PCV2) strain in China.

    PubMed

    Zhang, Dan; He, Kongwang; Wen, Libin; Fan, Hongjie

    2015-12-01

    Porcine circovirus type 2 (PCV2) is the etiological agent associated with several pig diseases that are collectively referred to as porcine circovirus-associated disease (PCVAD). Unfortunately, PCV2 has had a serious economic impact on the swine industry. In this study, we report the genome sequence of a novel PCV2 isolate (JS2015) identified in pigs in Jiang Su, China. The complete DNA sequence was 1766 nucleotides long with an A+T content of 52.7 %. It lacked a guanine (G) at nucleotide position 1045 compared to other reference PCV2 strains with a sequence length of 1766 nucleotides. Genetic characterization and phylogenetic analysis showed that the isolate JS2015 was most closely related to members of the PCV2d (AY181946) lineage. Our data provide insight into the epidemiology of porcine circovirus and may facilitate further study of the origin and evolution of PCV2. PMID:26395090

  19. Expression of antigenic epitopes of porcine reproductive and respiratory syndrome virus (PRRSV) in a modified live-attenuated porcine circovirus type 2 (PCV2) vaccine virus (PCV1-2a) as a potential bivalent vaccine against both PCV2 and PRRSV.

    PubMed

    Piñeyro, Pablo E; Kenney, Scott P; Giménez-Lirola, Luis G; Heffron, C Lynn; Matzinger, Shannon R; Opriessnig, Tanja; Meng, Xiang-Jin

    2015-12-01

    Co-infection of pigs in the field with porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV) is common and poses a major concern in effective control of PCV2 and PRRSV. We previously demonstrated that insertion of foreign epitope tags in the C-terminus of PCV2 ORF2 produced infectious virions that elicited humoral immune responses against both PCV2 capsid and inserted epitope tags. In this study, we aimed to determine whether the non-pathogenic chimeric virus PCV1-2a, which is the basis for the licensed PCV2 vaccine Fostera™ PCV, can express PRRSV antigenic epitopes, thus generating dual immunity as a potential bivalent vaccine against both PCV2 and PPRSV. Four different linear B-cell antigenic epitopes of PRRSV were inserted into the C-terminus of the capsid gene of the PCV1-2a vaccine virus. We showed that insertion of 12 (PRRSV-GP2 epitope II, PRRSV-GP3 epitope I, and PRRSV-GP5 epitope I), and 14 (PRRSV-GP5 epitope IV) amino acid residues did not impair the replication of the resulting PCV1-2a-PRRSVEPI chimeric viruses in vitro. The four chimeric PCV1-2a viruses expressing PRRSV B-cell linear epitopes were successfully rescued and characterized. An immunogenicity study in pigs revealed that two of the four chimeric viruses, PCV1-2a-PRRSVEPIGP3IG and PCV1-2a-PRRSVEPIEPIGP5IV, elicited neutralizing antibodies against PRRSV VR2385 as well as PCV2 (strains PCV2a, PCV2b, and mPCV2b). The results have important implications for exploring the potential use of PCV1-2a vaccine virus as a live virus vector to develop bivalent MLVs against both PCV2 and PRRSV. PMID:26239318

  20. Shuttle Orbiter Atmospheric Revitalization Pressure Control Subsystem

    NASA Technical Reports Server (NTRS)

    Walleshauser, J. J.; Ord, G. R.; Prince, R. N.

    1982-01-01

    The Atmospheric Revitalization Pressure Control Subsystem (ARPCS) provides oxygen partial pressure and total pressure control for the habitable atmosphere of the Shuttle for either a one atmosphere environment or an emergency 8 PSIA mode. It consists of a Supply Panel, Control Panel, Cabin Pressure Relief Valves and Electronic Controllers. The panels control and monitor the oxygen and nitrogen supplies. The cabin pressure relief valves protect the habitable environment from overpressurization. Electronic controllers provide proper mixing of the two gases. This paper describes the ARPCS, addresses the changes in hardware that have occurred since the inception of the program; the performance of this subsystem during STS-1 and STS-2; and discusses future operation modes.

  1. Ventilative cooling

    E-print Network

    Graça, Guilherme Carrilho da, 1972-

    1999-01-01

    This thesis evaluates the performance of daytime and nighttime passive ventilation cooling strategies for Beijing, Shanghai and Tokyo. A new simulation method for cross-ventilated wind driven airflow is presented . This ...

  2. Characterization of the leukogram in PCV2 infected germ-free pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Porcine Circovirus (PCV) is a non-enveloped, single stranded DNA virus of the Circoviridae family containing a circular genome of approximately 1.76 kb. The first isolate was recovered as a contaminant of a porcine kidney cell line in1974. This isolate, known as PCV type 1, is considered non-patho...

  3. COMPARISON OF CYTOKINE PROFILES IN PIGS SINGULARLY OR COINFECTED WITH PCV2, OR MYCOPLASMA HYOPNEUMONIAE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objectives of this study were to determine immune gene expression profiles in tracheobronchial lymph nodes (TBLN) following experimental infection with Porcine circovirus type 2 (PCV2), Mycoplasma hyopneumoniae, and PCV2/M. hyopneumoniae coinfection and compare the profiles to those of uninfecte...

  4. Quantification of PCV2 capsid transcript in peripheral blood mononuclear cells (PBMCs) in vitro

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The presence of PCV2 DNA or spliced capsid mRNA (Cap mRNA) for viral replication was assessed following addition of PCV2 to resting or concanavalin A (ConA) stimulated peripheral blood mononuclear cells (PBMCs). Real-time PCR or real-time RT-PCR assays were used to measure viral DNA or Cap mRNA, res...

  5. Industrial ventilation

    NASA Astrophysics Data System (ADS)

    Goodfellow, H. D.

    Industrial ventilation design methodology, using computers and using fluid dynamic models, is considered. It is noted that the design of a ventilation system must be incorporated into the plant design and layout at the earliest conceptual stage of the project. A checklist of activities concerning the methodology for the design of a ventilation system for a new facility is given. A flow diagram of the computer ventilation model shows a typical input, the initialization and iteration loop, and the output. The application of the fluid dynamic modeling techniques include external and internal flow fields, and individual sources of heat and contaminants. Major activities for a ventilation field test program are also addressed.

  6. Association of pneumococcal conjugate vaccination with rates of ventilation tube insertion in Denmark: population-based register study

    PubMed Central

    Groth, Christina; Thomsen, Reimar W; Ovesen, Therese

    2015-01-01

    Objective To examine if the introduction of pneumococcal conjugate vaccine (PCV) in Denmark was associated with a decrease in the rate of ventilation tube (VT) insertions performed by office-based practising ear, nose and throat (ENT) specialists. Design Population-based register study based on prospectively collected data. Setting Central Denmark Region. Data on VT insertions performed by any office-based practising ENT specialist in the region were collected from the National Health Service Registry. Participants All children below the age of 2?years with a first-time VT insertion from 2001 through 2011. Main outcome measures Age-stratified and gender-stratified standardised incidence rates of first-time VT insertion, and incidence rate ratio for PCV period 2008–2011 compared with pre-PCV period 2001–2007. Results The annual incidence rate of first-time VT insertion in small children increased steadily from 64/1000 person-years in 2001 to 100/1000 person-years in 2011. The incidence rate ratio was 1.27 (95% CI 1.24 to 1.30) in the PCV period compared with the pre-PCV period. Conclusions The introduction of PCV into the Danish childhood immunisation programme in 2007 was not associated with a subsequent decrease in the rate of VT insertions among children below the age of 2?years. Instead, the rate continued to rise, as before the introduction of PCV. Trial registration number Danish Data Protection Agency: 2007-58-0010. PMID:26048205

  7. Oral application of freeze-dried yeast particles expressing the PCV2b Cap protein on their surface induce protection to subsequent PCV2b challenge in vivo

    PubMed Central

    Patterson, Robert; Eley, Thomas; Browne, Christopher; Martineau, Henny M.; Werling, Dirk

    2015-01-01

    Porcine circovirus type 2 (PCV2) is now endemic in every major pig producing country, causing PCV-associated disease (PCVAD), linked with large scale economic losses. Current vaccination strategies are based on the capsid protein of the virus and are reasonably successful in preventing PCVAD but fail to induce sterile immunity. Additionally, vaccinating whole herds is expensive and time consuming. In the present study a “proof of concept” vaccine trial was employed to test the effectiveness of powdered freeze-dried recombinant Saccharomyces cerevisiae yeast stably expressing the capsid protein of PCV2b on its surface as an orally applied vaccine. PCV2-free pigs were given 3 doses of vaccine or left un-vaccinated before challenge with a defined PCV2b strain. Rectal temperatures were measured and serum and faeces samples were collected weekly. At the end of the study, pigs were euthanized, tissue samples taken and tested for PCV2b load by qPCR and immunohistochemistry. The peak of viraemia in sera and faeces of unvaccinated pigs was higher than that of vaccinated pigs. Additionally more sIgA was found in faeces of vaccinated pigs than unvaccinated. Vaccination was associated with lower serum concentrations of TNF? and IL-1? but higher concentrations of IFN? and IFN? in comparison to the unvaccinated animals. At the end of the trial, a higher viral load was found in several lymphatic tissues and the ileum of unvaccinated pigs in comparison to vaccinated pigs. The difference between groups was especially apparent in the ileum. The results presented here demonstrate a possible use for recombinant S. cerevisiae expressing viral proteins as an oral vaccine against PCV2. A powdered freeze-dried recombinant S. cerevisiae used as an oral vaccine could be mixed with feed and may offer a cheap and less labour intensive alternative to inoculation with the additional advantage that no cooling chain would be required for vaccine transport and storage. PMID:26476879

  8. Efficacy of parenteral vaccination against porcine circovirus type 2 (PCV2) in seropositive piglets

    PubMed Central

    Gamage, Lakshman N.A.; McIntosh, Kathleen A.; Parker, Sarah; Harding, John; Krakowka, Steven; Ellis, John

    2012-01-01

    This study investigated if parenteral administration of a prototype adjuvanted vaccine against porcine circovirus type 2 (PCV2) could override maternally derived antibodies and induce acquired immunity in young piglets. Piglets with high levels of maternal PCV2 antibodies at 1 wk of age were randomly grouped into vaccinates and controls on the basis of body weight and inoculated with the vaccine or a control preparation twice, with an interval of 3 wk. Both groups were challenged 3 wk after the booster vaccination and euthanized 3 wk after challenge. The pigs were evaluated for clinical disease, histologic lesions in sections of gastric and left inguinal lymph nodes stained with hematoxylin and eosin, and the amount of PCV2 antigen in the lymph nodes by immunohistochemical study. The PCV2 antibody titers were monitored by competitive enzyme-linked immunosorbent assay throughout the experiment. The vaccinates showed significantly less decline (P < 0.05) in PCV2 antibody titers after the booster vaccination. Clinical disease did not develop in any of the piglets. The vaccinates and controls did not differ in either histologic lesions or amount of PCV2 antigen in the lymph nodes. This study demonstrated some evidence of priming of young piglets in the presence of maternal antibodies. Further studies are recommended to determine the optimum concentration of PCV2 antigen and a suitable adjuvant for the vaccine to achieve the full potential of the strategy of inducing acquired immunity in young piglets that have maternally derived antibodies. PMID:23543956

  9. Ventilation Model

    SciTech Connect

    H. Yang

    1999-11-04

    The purpose of this analysis and model report (AMR) for the Ventilation Model is to analyze the effects of pre-closure continuous ventilation in the Engineered Barrier System (EBS) emplacement drifts and provide heat removal data to support EBS design. It will also provide input data (initial conditions, and time varying boundary conditions) for the EBS post-closure performance assessment and the EBS Water Distribution and Removal Process Model. The objective of the analysis is to develop, describe, and apply calculation methods and models that can be used to predict thermal conditions within emplacement drifts under forced ventilation during the pre-closure period. The scope of this analysis includes: (1) Provide a general description of effects and heat transfer process of emplacement drift ventilation. (2) Develop a modeling approach to simulate the impacts of pre-closure ventilation on the thermal conditions in emplacement drifts. (3) Identify and document inputs to be used for modeling emplacement ventilation. (4) Perform calculations of temperatures and heat removal in the emplacement drift. (5) Address general considerations of the effect of water/moisture removal by ventilation on the repository thermal conditions. The numerical modeling in this document will be limited to heat-only modeling and calculations. Only a preliminary assessment of the heat/moisture ventilation effects and modeling method will be performed in this revision. Modeling of moisture effects on heat removal and emplacement drift temperature may be performed in the future.

  10. Ventilation Model

    SciTech Connect

    V. Chipman

    2002-10-05

    The purpose of the Ventilation Model is to simulate the heat transfer processes in and around waste emplacement drifts during periods of forced ventilation. The model evaluates the effects of emplacement drift ventilation on the thermal conditions in the emplacement drifts and surrounding rock mass, and calculates the heat removal by ventilation as a measure of the viability of ventilation to delay the onset of peak repository temperature and reduce its magnitude. The heat removal by ventilation is temporally and spatially dependent, and is expressed as the fraction of heat carried away by the ventilation air compared to the fraction of heat produced by radionuclide decay. One minus the heat removal is called the wall heat fraction, or the remaining amount of heat that is transferred via conduction to the surrounding rock mass. Downstream models, such as the ''Multiscale Thermohydrologic Model'' (BSC 2001), use the wall heat fractions as outputted from the Ventilation Model to initialize their post-closure analyses. The Ventilation Model report was initially developed to analyze the effects of preclosure continuous ventilation in the Engineered Barrier System (EBS) emplacement drifts, and to provide heat removal data to support EBS design. Revision 00 of the Ventilation Model included documentation of the modeling results from the ANSYS-based heat transfer model. The purposes of Revision 01 of the Ventilation Model are: (1) To validate the conceptual model for preclosure ventilation of emplacement drifts and verify its numerical application in accordance with new procedural requirements as outlined in AP-SIII-10Q, Models (Section 7.0). (2) To satisfy technical issues posed in KTI agreement RDTME 3.14 (Reamer and Williams 2001a). Specifically to demonstrate, with respect to the ANSYS ventilation model, the adequacy of the discretization (Section 6.2.3.1), and the downstream applicability of the model results (i.e. wall heat fractions) to initialize post-closure thermal models (Section 6.6). (3) To satisfy the remainder of KTI agreement TEF 2.07 (Reamer and Williams 2001b). Specifically to provide the results of post-test ANSYS modeling of the Atlas Facility forced convection tests (Section 7.1.2). This portion of the model report also serves as a validation exercise per AP-SIII.10Q, Models, for the ANSYS ventilation model. (4) To further satisfy KTI agreements RDTME 3.01 and 3.14 (Reamer and Williams 2001a) by providing the source documentation referred to in the KTI Letter Report, ''Effect of Forced Ventilation on Thermal-Hydrologic Conditions in the Engineered Barrier System and Near Field Environment'' (Williams 2002). Specifically to provide the results of the MULTIFLUX model which simulates the coupled processes of heat and mass transfer in and around waste emplacement drifts during periods of forced ventilation. This portion of the model report is presented as an Alternative Conceptual Model with a numerical application, and also provides corroborative results used for model validation purposes (Section 6.3 and 6.4).

  11. Identification of microRNAs in PCV2 subclinically infected pigs by high throughput sequencing.

    PubMed

    Núñez-Hernández, Fernando; Pérez, Lester J; Muñoz, Marta; Vera, Gonzalo; Tomás, Anna; Egea, Raquel; Córdoba, Sarai; Segalés, Joaquim; Sánchez, Armand; Núñez, José I

    2015-01-01

    Porcine circovirus type 2 (PCV2) is the essential etiological infectious agent of PCV2-systemic disease and has been associated with other swine diseases, all of them collectively known as porcine circovirus diseases. MicroRNAs (miRNAs) are a new class of small non-coding RNAs that regulate gene expression post-transcriptionally. miRNAs play an increasing role in many biological processes. The study of miRNA-mediated host-pathogen interactions has emerged in the last decade due to the important role that miRNAs play in antiviral defense. The objective of this study was to identify the miRNA expression pattern in PCV2 subclinically infected and non-infected pigs. For this purpose an experimental PCV2 infection was carried out and small-RNA libraries were constructed from tonsil and mediastinal lymph node (MLN) of infected and non-infected pigs. High throughput sequencing determined differences in miRNA expression in MLN between infected and non-infected while, in tonsil, a very conserved pattern was observed. In MLN, miRNA 126-3p, miRNA 126-5p, let-7d-3p, mir-129a and mir-let-7b-3p were up-regulated whereas mir-193a-5p, mir-574-5p and mir-34a down-regulated. Prediction of functional analysis showed that these miRNAs can be involved in pathways related to immune system and in processes related to the pathogenesis of PCV2, although functional assays are needed to support these predictions. This is the first study on miRNA gene expression in pigs infected with PCV2 using a high throughput sequencing approach in which several host miRNAs were differentially expressed in response to PCV2 infection. PMID:25879589

  12. Ear necrosis syndrome in weaning pigs associated with PCV2 infection: A case report

    PubMed Central

    Papatsiros, Vassilis

    2012-01-01

    Porcine necrotic ear syndrome (PNES) in pigs has been reported as an increasing health problem in many countries with intensive pig farming. The etiology of this disease is complex and the presumed triggering factors can be divided into infectious and non-infectious agents. The present report describes a case of Porcine Circovirus type 2 (PCV2), infection associated with lesions of PNES at the weaning stage of a farrow-to-finish pig farm. Approximately 35% of weaners (1-3 weeks after weaning) presented clinical symptoms similar to Post-weaning Multisystemic Wasting Syndrome (PMWS). About 2-3 weeks after weaning the first lesions of PNES occurred in approximately 20% of pigs, resulting in a significant health problem characterized by poor growth or severe wasting and finally mortality up to 15% in some batches. Moreover, approximately 5% of survived weaners, during growing / finishing stage, presented poor growth and secondary co-infections that lead to death. The present study based on the clinical signs, serological and pathological examinations, indicates that weaners suffered by sub-acute PCV2 infection resulting in PMWS associated with PNES. The lesions of PNES were initially observed at the same period (4-8 weeks of age) with the higher seroprevalence of PCV2 infection. Metaphylaxis of this case included intramuscular injection of florfenicol for the treatment and control of skin lesions and respiratory signs. Moreover, piglets were vaccinated against PCV2. In conclusion, sub-acute PCV2 infection could be included in triggering factors PNES in weaners. The mass vaccination against PCV2 of infected piglets might be effective in reduction of clinical signs and losses of PNES in cases of PCV2 infection associated with PNES. PMID:25610573

  13. A Porcine Circovirus Type 2 (PCV2) Mutant with 234 Amino Acids in Capsid Protein Showed More Virulence In Vivo, Compared with Classical PCV2a/b Strain

    PubMed Central

    Guo, Longjun; Fu, Yujie; Wang, Yiping; Lu, Yuehua; Wei, Yanwu; Tang, Qinghai; Fan, Peihu; Liu, Jianbo; Zhang, Long; Zhang, Feiyan; Huang, Liping; Liu, Dan; Li, Shengbin; Wu, Hongli; Liu, Changming

    2012-01-01

    Background Porcine circovirus type 2 (PCV2) is considered to be the primary causative agent of postweaning multisystemic wasting syndrome (PMWS), which has become a serious economic problem for the swine industry worldwide. The major genotypes, PCV2a and PCV2b, are highly prevalent in the pig population and are present worldwide. However, another newly emerging PCV2b genotype mutant, which has a mutation in its ORF2-encoded capsid protein, has been sporadically present in China, as well as in other countries. It is therefore important to determine the relative virulence of the newly emerging PCV2b genotype mutant, compared with the existing PCV2a and PCV2b genotypes, and to investigate whether the newly emerging mutant virus induces more severe illness. Methodology/Principal Findings Twenty healthy, 30-day-old, commercial piglets served as controls or were challenged with PCV2a, PCV2b and the newly emerging mutant virus. A series of indexes representing different parameters were adopted to evaluate virulence, including clinical signs, serological detection, viral load and distribution, changes in immune cell subsets in the peripheral blood, and evaluation of pathological lesions. The newly emerging PCV2 mutant demonstrated more severe signs compatible with PMWS, characterized by wasting, coughing, dyspnea, diarrhea, rough hair-coat and depression. Moreover, the pathological lesions and viremia, as well as the viral loads in lymph nodes, tonsils and spleen, were significantly more severe (P<0.05) for piglets challenged with the newly emerging mutant compared with those in the groups challenged with PCV2a and PCV2b. In addition, a significantly lower average daily weight gain (P<0.05) was recorded in the group challenged with the newly emerging PCV2 mutant than in the groups challenged with the prevailing PCV2a and PCV2b. Conclusions This is believed to be the first report to confirm the enhanced virulence of the newly emerging PCV2 mutant in vivo. PMID:22829951

  14. Review of Residential Ventilation Technologies

    SciTech Connect

    Russell, Marion L.; Sherman, Max H.; Rudd, Armin

    2005-03-01

    This paper reviews current and potential ventilation technologies for residential buildings in North America and a few in Europe. The major technologies reviewed include a variety of mechanical systems, natural ventilation, and passive ventilation. Key parameters that are related to each system include operating costs, installation costs, ventilation rates, heat recovery potential. It also examines related issues such as infiltration, duct systems, filtration options, noise, and construction issues. This report describes a wide variety of systems currently on the market that can be used to meet ASHRAE standard 62.2. While these systems generally fall into the categories of supply, exhaust or balanced, the specifics of each system are driven by concerns that extend beyond those in the standard and are discussed. Some of these systems go beyond the current standard by providing additional features (such as air distribution or pressurization control). The market will decide the immediate value of such features, but ASHRAE may wish to consider modifications to the standard in the future.

  15. Liquid ventilation.

    PubMed

    Sarkar, Suman; Paswan, Anil; Prakas, S

    2014-01-01

    Human have lungs to breathe air and they have no gills to breath liquids like fish. When the surface tension at the air-liquid interface of the lung increases as in acute lung injury, scientists started to think about filling the lung with fluid instead of air to reduce the surface tension and facilitate ventilation. Liquid ventilation (LV) is a technique of mechanical ventilation in which the lungs are insufflated with an oxygenated perfluorochemical liquid rather than an oxygen-containing gas mixture. The use of perfluorochemicals, rather than nitrogen as the inert carrier of oxygen and carbon dioxide offers a number of advantages for the treatment of acute lung injury. In addition, there are non-respiratory applications with expanding potential including pulmonary drug delivery and radiographic imaging. It is well-known that respiratory diseases are one of the most common causes of morbidity and mortality in intensive care unit. During the past few years several new modalities of treatment have been introduced. One of them and probably the most fascinating, is of LV. Partial LV, on which much of the existing research has concentrated, requires partial filling of lungs with perfluorocarbons (PFC's) and ventilation with gas tidal volumes using conventional mechanical ventilators. Various physico-chemical properties of PFC's make them the ideal media. It results in a dramatic improvement in lung compliance and oxygenation and decline in mean airway pressure and oxygen requirements. No long-term side-effect reported. PMID:25886321

  16. 112. REFRIGERANT CONDENSER TANKS AND PRESSURE CONTROLS IN NORTHEAST CORNER ...

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

    112. REFRIGERANT CONDENSER TANKS AND PRESSURE CONTROLS IN NORTHEAST CORNER OF MECHANICAL EQUIPMENT ROOM (201), LSB (BLDG. 751) - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  17. Assessing PCV2 antibodies in field pigs vaccinated with different porcine circovirus 2 vaccines using two commercial ELISA systems

    PubMed Central

    Shin, Min-Kyoung; Yoon, Seung Hyun; Kim, Myung Hwui; Lyoo, Young Soo; Suh, Seung Won

    2015-01-01

    Porcine circovirus type 2 (PCV2) is the primary causative agent for post-weaning, multisystemic, wasting syndrome. Consequently, serologic detection of and vaccination against PCV2 are important for the swine industry. Among several serological tests, the enzyme-linked immunosorbent assay (ELISA) is commonly used to measure anti-PCV2 antibody levels. In the present study, we used two commercial ELISA systems to comparatively evaluate anti-PCV2 antibodies in field pigs treated with three different PCV2 vaccines. Among a total of 517 serum samples, the results of the two ELISAs were fully concordant for 365 positive and 42 negative samples, indicating 78.7% agreement. In addition, the Pearson coefficient (0.636) indicated a moderate correlation between data from the two ELISAs. Results from the farms with pigs vaccinated with the three different PCV2 vaccines demonstrated that most of the vaccinated animals underwent seroconversion. However, the increase and duration of antibody titers varied depending on the vaccine, the presence of maternal antibodies, and the vaccination program. PCV2 serologic status and anti-PCV2 antibody levels of herds from this study could be utilized to determine the best timing for vaccination and assessing vaccination compliance. PMID:25234326

  18. Ventilator waveforms.

    PubMed

    Mellema, Matthew S

    2013-08-01

    Ventilator waveforms are graphic representations of changes in pressure, flow, and volume within a ventilator circuit. The changes in these parameters over time may be displayed individually (scalars) or plotted one against another (pressure-volume and flow-volume loops). There are 6 basic shapes of scalar waveforms, but only 3 are functionally distinct (square, ramp, and sine). The pressure scalar is a particularly valuable tool when constant flow (e.g., volume control) modes are employed and an inspiratory pause is added. In this setting, inspection of the pressure waveform can allow determination of static, quasistatic, and dynamic compliance, as well as relative changes in airway resistance. Inspection of the pressure waveform can also help to identify many important aspects of patient drug responses, dyssynchrony, and air trapping (auto positive end-expiratory pressure [auto-PEEP]). Depending on the ventilation mode employed, the shape of the flow waveform may be set by the ventilator operator or may be dependent on patient effort and lung mechanics. Decelerating flow patterns have several important advantages when this option is available. Inspection of flow waveforms is crucial in the recognition of dyssynchrony, setting optimal inspiratory times, evaluating responses to bronchodilators, and the recognition of auto-PEEP. The volume waveform often contains somewhat less useful information than the other 2 scalars, but plays a crucial role in the identification of leaks in the circuit. Pressure-volume loops are particularly useful in setting PEEP and peak inspiratory pressure ranges. Inspection of these loops also often helps in the evaluation of lung mechanics, in the identification of circuit leaks, and in the assessment of patient triggering effort. Flow-volume loops are extremely useful in the identification of leaks and excessive airway secretions as well as alterations in airway resistance. Lastly, serial waveform inspection is crucial to the identification and resolution of patient-ventilator dyssynchrony in many cases. PMID:24183000

  19. Optimization on Preparation Conditions of Salidroside Liposome and Its Immunological Activity on PCV-2 in Mice

    PubMed Central

    Feng, Yibo; Zhao, Xiaojuan; Lv, Fang; Zhang, Jinqiu; Deng, Bihua; Zhao, Yanhong; Hu, Yuanliang; Wang, Deyun; Liu, Jiaguo; Lu, Yu; Bo, Ruonan; Liu, Zhenguang

    2015-01-01

    The aim of this study was to optimize the preparation conditions of salidroside liposome with high encapsulation efficiency (EE) and to study the immunological enhancement activity of salidroside liposome as porcine circovirus type 2 virus (PCV-2) vaccine adjuvant. Response surface methodology (RSM) was selected to optimize the conditions for the preparation of salidroside liposome using Design-Expert V8.0.6 software. Three kinds of salidroside liposome adjuvants were prepared to study their adjuvant activity. BALB/c mice were immunized with PCV-2 encapsulated in different kinds of salidroside liposome adjuvants. The PCV-2-specific IgG in immunized mice serum was determined with ELISA. The results showed that when the concentration of ammonium sulfate was 0.26?mol·L?1, ethanol volume 6.5?mL, temperature 43°C, ethanol injection rate 3?mL·min?1, and salidroside liposome could be prepared with high encapsulation efficiency of 94.527%. Salidroside liposome as adjuvant could rapidly induce the production of PCV-2-specific IgG and salidroside liposome I adjuvant proved to provide the best effect among the three kinds of salidroside liposome adjuvants. PMID:25878712

  20. Mortality in pigs given PCV2 virus derived from DNA clones

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The clinical presentation following infection with porcine circovirus type 2 (PCV2) ranges from sub-clinical to one of several disease states known collectively as porcine circovirus diseases (PCVD). In 2005 a disease spread rapidly through finishing barns in the U. S. that was recognized as an acut...

  1. Differential recognition of the ORF2 region in a complete genome sequence of porcine circovirus type 2 (PCV2) isolated from boar bone marrow in Korea.

    PubMed

    Kweon, Chang-Hee; Nguyen, Lien Thi Kim; Yoo, Mi-Sun; Kang, Seung-Won

    2015-09-15

    Porcine circovirus type 2 (PCV2) is the causative agent of post-weaning multisystemic wasting syndrome (PMWS) in swine. Here, a phylogenetic tree was constructed using PCV2 nucleotide sequences derived from the bone marrow of Korean boar and previously reported PCV2 sequences isolated from various countries. PCV2 from Korean boar bone marrow (KC188796) was classified into the group containing PCV2a-Canada and other PCV2 strain from Korea. While the ORF1 region of the PCV2 genome was highly conserved, ORF2 (the capsid protein coding region) was relatively variable. The nucleotide sequences for bone marrow-derived PCV2 were 93.4-99.0% homologous to the other reference sequences. The deduced amino acid sequences for the ORF1 and ORF2 coding regions were 97.4-99.3% and 84.5-97.4% homologous with the other reference strains, respectively, indicating that KC188796 did not differ markedly from the other PCV2 strains. Phylogenetic analysis demonstrated that bone marrow-derived PCV2 was highly similar to PCV2a from Canada and may be related to persistent PCV2 infections in swine. PMID:25917618

  2. Efficacy of a new bivalent vaccine of porcine circovirus type 2 and Mycoplasma hyopneumoniae (Fostera™ PCV MH) under experimental conditions.

    PubMed

    Park, Changhoon; Jeong, Jiwoon; Choi, Kyuhyung; Chae, Chanhee

    2016-01-01

    The objective of this study was to evaluate the efficacy of a new bivalent vaccine (Fostera™ PCV MH, Zoetis) of porcine circovirus type 2 (PCV2) and Mycoplasma hyopneumoniae in growing pigs under experimental conditions. A total of 80 pigs were randomly divided into 8 groups (10 pigs per group). The pigs were administered the bivalent vaccine intramuscularly as a 2.0mL dose at 21 days of age based on the manufacturer's instructions. Three weeks after vaccination, the pigs were inoculated with either PCV2 (intranasal route) or M. hyopneumoniae (intratracheal route) or both. Regardless of the type of inoculation, vaccinated pigs after challenge exhibited effective reduction of clinical signs, PCV2 viremia levels and mycoplasma nasal shedding, and lung and lymphoid lesion when compared to unvaccinated challenged pigs. Vaccinated challenged pigs had significantly higher (P<0.05) levels of PCV2-specific neutralizing antibodies, and numbers of PCV2-and M. hyopneumoniae-specific interferon-? secreting cells compared to unvaccinated challenged pigs. This study demonstrates that the bivalent vaccine is able to protect pigs against either PCV2 or M. hyopneumoniae infection or both based on clinical, microbiological, immunological, and pathological evaluation. PMID:26626212

  3. Sow porcine circovirus type 2 (PCV2) status effect on litter mortality in postweaning multisystemic wasting syndrome (PMWS).

    PubMed

    Calsamiglia, M; Fraile, L; Espinal, A; Cuxart, A; Seminati, C; Martín, M; Mateu, E; Domingo, M; Segalés, J

    2007-06-01

    Previous studies have described a "litter effect" associated with mortality in postweaning multisystemic wasting syndrome (PMWS) affected farms. The main objective of this study was to evaluate litter mortality in different PMWS affected farms and to characterize it in relation to three variables of the sow: parity, porcine circovirus type 2 (PCV2) infectious status and PCV2 antibody titres. The study was performed in seven farms that experienced PMWS in nurseries and/or fattening areas. Fifteen sows from each farm were randomly selected from the same farrowing batch. Serum samples were analyzed for antibodies to PCV2 and for genomic detection of PCV2. Four piglets from each sow (60 piglets per farm) were selected and ear-tagged at birth. Out of 420 initial piglets, 104 (25%) died. Sixty three of them (60%) were necropsied, and 40 (63%) diagnosed as PMWS based on case definition criteria. Our results show that sow PCV2 viremia was significantly related to piglet mortality since more piglets per litter died from viremic than from non-viremic sows. Additionally, a significantly greater proportion of animals died from sows that had low antibody titres against PCV2 (39% vs. 18% from sows with medium to high antibody titres). The present study, of exploratory nature, confirms previous results and further characterizes the so called "litter effect" by establishing that the sow PCV2 status had a significant effect on litter mortality in PMWS affected farms. PMID:17064740

  4. PCV2 vaccination induces IFN-?/TNF-? co-producing T cells with a potential role in protection.

    PubMed

    Koinig, Hanna C; Talker, Stephanie C; Stadler, Maria; Ladinig, Andrea; Graage, Robert; Ritzmann, Mathias; Hennig-Pauka, Isabel; Gerner, Wilhelm; Saalmüller, Armin

    2015-01-01

    Porcine circovirus type 2 (PCV2) is one of the economically most important pathogens for swine production worldwide. Vaccination is a powerful tool to control porcine circovirus diseases (PCVD). However, it is not fully understood how PCV2 vaccination interacts with the porcine immune system. Especially knowledge on the cellular immune response against PCV2 is sparse. In this study we analysed antigen-specific T cell responses against PCV2 in a controlled vaccination and infection experiment. We focused on the ability of CD4(+) T cells to produce cytokines using multicolour flow cytometry (FCM). Vaccination with a PCV2 subunit vaccine (Ingelvac CircoFLEX®) induced PCV2-specific antibodies only in five out of 12 animals. Conversely, vaccine-antigen specific CD4(+) T cells which simultaneously produced IFN-? and TNF-? and had a phenotype of central and effector memory T cells were detected in all vaccinated piglets. After challenge, seroconversion occurred earlier in vaccinated and infected pigs compared to the non-vaccinated, infected group. Vaccinated pigs were fully protected against viremia after subsequent challenge. Therefore, our data suggests that the induction of IFN-?/TNF-? co-producing T cells by PCV2 vaccination may serve as a potential correlate of protection for this type of vaccine. PMID:25888899

  5. 142. STANDBY PRESSURE CONTROL UNIT FOR FUEL AND LIQUID OXYGEN ...

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

    142. STANDBY PRESSURE CONTROL UNIT FOR FUEL AND LIQUID OXYGEN IN SOUTHWEST PORTION OF CONTROL ROOM (214), LSB (BLDG. 751), FACING WEST - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  6. Epidemiology of Streptococcus pneumoniae in France before introduction of the PCV-13 vaccine.

    PubMed

    Grall, N; Hurmic, O; Al Nakib, M; Longo, M; Poyart, C; Ploy, M-C; Varon, E; Raymond, J

    2011-12-01

    The purpose of this article was to describe the serotype incidence and antibiotic susceptibility of Streptococcus pneumoniae strains isolated from adults and children with invasive disease (IPD) or acute otitis media (AOM) before introduction of the 13-valent pneumococcal vaccine. During 2009, 494 strains of S. pneumoniae isolated were collected. Complete serotyping by latex antisera and molecular methods was performed. The most frequent serotypes isolated from children with IPD were 1 (26.2%), 19A (25%) and 7F (14.3%). Serotype 19A was predominant (42.1%) in children???2 years, whereas serotype 1 was predominant (63.3%) after the age of 5. Serotype 19A was the most frequently isolated serotype from AOM (62.3%). In adults, serotypes responsible for IPD were 7F (19.4%), 19A (13.7%), 1 (8.4%) and 3 (7.5%). The serotype 19A was predominant in adults older than 65 years (19.1%). The emergence of serotype 12F was observed in adults. Between 2007 and 2009, the introduction of PCV-7 has resulted in a significant decrease of IPD caused by serotypes included in the vaccine, in children as well as in adults, confirming the herd effect. Serotype coverage of PCV-13 was 70% and 80.9% for adult and children's IPD, respectively. PCV-13 will be more efficient in preventing invasive diseases among children and adults. PMID:21499971

  7. VENTILATION NEEDS DURING CONSTRUCTION

    SciTech Connect

    C.R. Gorrell

    1998-07-23

    The purpose of this analysis is to determine ventilation needs during construction and development of the subsurface repository and develop systems to satisfy those needs. For this analysis, construction is defined as pre-emplacement excavation and development is excavation that takes place simultaneously with emplacement. The three options presented in the ''Overall Development and Emplacement Ventilation Systems'' analysis (Reference 5.5) for development ventilation will be applied to construction ventilation in this analysis as well as adding new and updated ventilation factors to each option for both construction and development. The objective of this analysis is to develop a preferred ventilation system to support License Application Design. The scope of this analysis includes: (1) Description of ventilation conditions; (2) Ventilation factors (fire hazards, dust control, construction logistics, and monitoring and control systems); (3) Local ventilation alternatives; (4) Global ventilation options; and (5) Evaluation of options.

  8. A live-attenuated chimeric PCV2 vaccine based on subtype 2b is transmitted to contact pigs but is not upregulated by concurrent infection with PPV and PRRSV and is efficacious in a triple challenge co-infection model

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to determine the safety and efficacy of a new live-attenuated chimeric PCV1/2b vaccine. Forty-six, 21-day-old, PCV2-naïve pigs were randomly assigned to one of six groups (Negative controls, positive controls, Vac-0, Vac-0-PCV2, Contact-PCV2, Vac-28-PCV2). All pigs we...

  9. Neurally adjusted ventilator assist in very low birth weight infants: Current status.

    PubMed

    Narchi, Hassib; Chedid, Fares

    2015-06-26

    Continuous improvements in perinatal care have resulted in increased survival of premature infants. Their immature lungs are prone to injury with mechanical ventilation and this may develop into chronic lung disease (CLD) or bronchopulmonary dysplasia. Strategies to minimize the risk of lung injury have been developed and include improved antenatal management (education, regionalization, steroids, and antibiotics), exogenous surfactant administration and reduction of barotrauma by using exclusive or early noninvasive ventilatory support. The most frequently used mode of assisted ventilation is pressure support ventilation that may lead to patient-ventilator asynchrony that is associated with poor outcome. Ventilator-induced diaphragmatic dysfunction or disuse atrophy of diaphragm fibers may also occur. This has led to the development of new ventilation modes including neurally adjusted ventilatory assist (NAVA). This ventilation mode is controlled by electrodes embedded within a nasogastric catheter which detect the electrical diaphragmatic activity (Edi) and transmit it to trigger the ventilator in synchrony with the patient's own respiratory efforts. This permits the patient to control peak inspiratory pressure, mean airway pressure and tidal volume. Back up pressure control (PC) is provided when there is no Edi signal and no pneumatic trigger. Compared with standard conventional ventilation, NAVA improves blood gas regulation with lower peak inspiratory pressure and oxygen requirements in preterm infants. NAVA is safe mode of ventilation. The majority of studies have shown no significant adverse events in neonates ventilated with NAVA nor a difference in the rate of intraventricular hemorrhage, pneumothorax, or necrotizing enterocolitis when compared to conventional ventilation. Future large size randomized controlled trials should be established to compare NAVA with volume targeted and pressure controlled ventilation in newborns with mature respiratory drive. Most previous studies and trials were not sufficiently large and did not include long-term patient oriented outcomes. Multicenter, randomized, outcome trials are needed to determine whether NAVA is effective in avoiding intubation, facilitating extubation, decreasing time of ventilation, reducing the incidence of CLD, decreasing length of stay, and improving long-term outcomes such as the duration of ventilation, length of hospital stay, rate of pneumothorax, CLD and other major complications of prematurity. In order to prevent barotrauma, next generations of NAVA equipment for neonatal use should enable automatic setting of ventilator parameters in the backup PC mode based on the values generated by NAVA. They should also include an upper limit to the inspiratory time as in conventional ventilation. The manufacturers of Edi catheters should produce smaller sizes available for extreme low birth weight infants. Newly developed ventilators should also include leak compensation and high frequency ventilation. A peripheral flow sensor is also essential to the proper delivery of all modes of conventional ventilation as well as NAVA. PMID:26140273

  10. Neurally adjusted ventilator assist in very low birth weight infants: Current status

    PubMed Central

    Narchi, Hassib; Chedid, Fares

    2015-01-01

    Continuous improvements in perinatal care have resulted in increased survival of premature infants. Their immature lungs are prone to injury with mechanical ventilation and this may develop into chronic lung disease (CLD) or bronchopulmonary dysplasia. Strategies to minimize the risk of lung injury have been developed and include improved antenatal management (education, regionalization, steroids, and antibiotics), exogenous surfactant administration and reduction of barotrauma by using exclusive or early noninvasive ventilatory support. The most frequently used mode of assisted ventilation is pressure support ventilation that may lead to patient-ventilator asynchrony that is associated with poor outcome. Ventilator-induced diaphragmatic dysfunction or disuse atrophy of diaphragm fibers may also occur. This has led to the development of new ventilation modes including neurally adjusted ventilatory assist (NAVA). This ventilation mode is controlled by electrodes embedded within a nasogastric catheter which detect the electrical diaphragmatic activity (Edi) and transmit it to trigger the ventilator in synchrony with the patient’s own respiratory efforts. This permits the patient to control peak inspiratory pressure, mean airway pressure and tidal volume. Back up pressure control (PC) is provided when there is no Edi signal and no pneumatic trigger. Compared with standard conventional ventilation, NAVA improves blood gas regulation with lower peak inspiratory pressure and oxygen requirements in preterm infants. NAVA is safe mode of ventilation. The majority of studies have shown no significant adverse events in neonates ventilated with NAVA nor a difference in the rate of intraventricular hemorrhage, pneumothorax, or necrotizing enterocolitis when compared to conventional ventilation. Future large size randomized controlled trials should be established to compare NAVA with volume targeted and pressure controlled ventilation in newborns with mature respiratory drive. Most previous studies and trials were not sufficiently large and did not include long-term patient oriented outcomes. Multicenter, randomized, outcome trials are needed to determine whether NAVA is effective in avoiding intubation, facilitating extubation, decreasing time of ventilation, reducing the incidence of CLD, decreasing length of stay, and improving long-term outcomes such as the duration of ventilation, length of hospital stay, rate of pneumothorax, CLD and other major complications of prematurity. In order to prevent barotrauma, next generations of NAVA equipment for neonatal use should enable automatic setting of ventilator parameters in the backup PC mode based on the values generated by NAVA. They should also include an upper limit to the inspiratory time as in conventional ventilation. The manufacturers of Edi catheters should produce smaller sizes available for extreme low birth weight infants. Newly developed ventilators should also include leak compensation and high frequency ventilation. A peripheral flow sensor is also essential to the proper delivery of all modes of conventional ventilation as well as NAVA. PMID:26140273

  11. Cryogenic Pressure Control Modeling for Ellipsoidal Space Tanks

    NASA Technical Reports Server (NTRS)

    Lopez, Alfredo; Grayson, Gary D.; Chandler, Frank O.; Hastings, Leon J.; Heyadat, Ali

    2007-01-01

    A computational fluid dynamics (CFD) model is developed to simulate pressure control of an ellipsoidal-shaped liquid hydrogen tank under external heating in normal gravity. Pressure control is provided by an axial jet thermodynamic vent system (TVS) centered within the vessel that injects cooler liquid into the tank, mixing the contents and reducing tank pressure. The two-phase cryogenic tank model considers liquid hydrogen in its own vapor with liquid density varying with temperature only and a fully compressible ullage. The axisymmetric model is developed using a custom version of the commercially available FLOW-31) software. Quantitative model validation is ,provided by engineering checkout tests performed at Marshall Space Flight Center in 1999 in support of the Solar Thermal Upper Stage_ Technology Demonstrator (STUSTD) program. The engineering checkout tests provide cryogenic tank self-pressurization test data at various heat leaks and tank fill levels. The predicted self-pressurization rates, ullage and liquid temperatures at discrete locations within the STUSTD tank are in good agreement with test data. The work presented here advances current CFD modeling capabilities for cryogenic pressure control and helps develop a low cost CFD-based design process for space hardware.

  12. Porcine circovirus type 2 (PCV2) infection decreases the efficacy of an attenuated classical swine fever virus (CSFV) vaccine.

    PubMed

    Huang, Yu-Liang; Pang, Victor Fei; Lin, Chun-Ming; Tsai, Yi-Chieh; Chia, Mi-Yuan; Deng, Ming-Chung; Chang, Chia-Yi; Jeng, Chian-Ren

    2011-01-01

    The Lapinized Philippines Coronel (LPC) vaccine, an attenuated strain of classical swine fever virus (CSFV), is an important tool for the prevention and control of CSFV infection and is widely and routinely used in most CSF endemic areas, including Taiwan. The aim of this study was to investigate whether PCV2 infection affects the efficacy of the LPC vaccine. Eighteen 6-week-old, cesarean-derived and colostrum-deprived (CDCD), crossbred pigs were randomly assigned to four groups. A total of 10(5.3) TCID50 of PCV2 was experimentally inoculated into pigs through both intranasal and intramuscular routes at 0 days post-inoculation (dpi) followed by LPC vaccination 12 days later. All the animals were challenged with wild-type CSFV (ALD stain) at 27 dpi and euthanized at 45 dpi. Following CSFV challenge, the LPC-vaccinated pigs pre-inoculated with PCV2 showed transient fever, viremia, and viral shedding in the saliva and feces. The number of IgM(+), CD4(+)CD8-CD25(+), CD4(+)CD8(+)CD25(+), and CD4(-)CD8(+)CD25(+) lymphocyte subsets and the level of neutralizing antibodies against CSFV were significantly higher in the animals with LPC vaccination alone than in the pigs with PCV2 inoculation/LPC vaccination. In addition, PCV2-derived inhibition of the CSFV-specific cell proliferative response of peripheral blood mononuclear cells (PBMCs) was demonstrated in an ex vivo experiment. These findings indicate that PCV2 infection decreases the efficacy of the LPC vaccine. This PCV2-derived interference may not only allow the invasion of wild-type CSFV in pig farms but also increases the difficulty of CSF prevention and control in CSF endemic areas. PMID:22129109

  13. A nurse's guide to common mechanical ventilation techniques and modes used in infants. Nursing implications.

    PubMed

    Snow, Timothy M; Brandon, Debra H

    2007-02-01

    The need for conventional mechanical ventilation (CMV) is a common one in the neonatal intensive care unit (NICU). The goals of CMV are to facilitate adequate gas exchange, minimize the risk of lung injury/damage, decrease the patient's work of breathing, and optimize the patient's comfort. Although time-cycled, pressure-limited ventilation remains the most common CMV modality, volume-cycled ventilation, assist-control ventilation, pressure-support ventilation, and pressure-control ventilation are sometimes used in the NICU. Pressure-regulated volume control, volume-guaranteed ventilation, volume-assured pressure-support ventilation, and proportional-assist ventilation are emerging hybrid modes of CMV. Although CMV is frequently life saving, it can cause complications if improperly used. Nurses are responsible for the ongoing assessment and care of infants undergoing CMV and are becoming frequently more involved in the weaning process of CMV. This article provides an overview of conventional ventilation, with a focus on common modalities, and ventilation-related nursing interventions. PMID:17536329

  14. Airway pressure release ventilation: improving oxygenation: indications, rationale, and adverse events associated with airway pressure release ventilation in patients with acute respiratory distress syndrome for advance practice nurses.

    PubMed

    Ferdowsali, Kameron; Modock, Jacqueline

    2013-01-01

    Airway pressure release ventilation (APRV) is a mode of ventilation that has been around since the 1980s and was originally viewed as a type of continuous positive pressure mode of ventilation. Conceptually, APRV can be thought of as a type of inverse-ratio, pressure-controlled, intermittent mandatory ventilation during which the maintenance of spontaneous breathing and prolonged application of high mean airway pressure contribute to the clinical benefits. The aim of this review article was to familiarize the bedside clinician working in the intensive care unit with the theory and rationale behind this mode of ventilation. The potential advantages and disadvantages of APRV will also be discussed to empower the advance practice clinician and bedside nurse to advocate for their patient diagnosed with the often-high mortality disease of acute respiratory distress syndrome. PMID:23933639

  15. Intensive Blood-Pressure Control in Hypertensive Chronic Kidney Disease

    PubMed Central

    Appel, Lawrence J.; Wright, Jackson T.; Greene, Tom; Agodoa, Lawrence Y.; Astor, Brad C.; Bakris, George L.; Cleveland, William H.; Charleston, Jeanne; Contreras, Gabriel; Faulkner, Marquetta L.; Gabbai, Francis B.; Gassman, Jennifer J.; Hebert, Lee A.; Jamerson, Kenneth A.; Kopple, Joel D.; Kusek, John W.; Lash, James P.; Lea, Janice P.; Lewis, Julia B.; Lipkowitz, Michael S.; Massry, Shaul G.; Miller, Edgar R.; Norris, Keith; Phillips, Robert A.; Pogue, Velvie A.; Randall, Otelio S.; Rostand, Stephen G.; Smogorzewski, Miroslaw J.; Toto, Robert D.; Wang, Xuelei

    2013-01-01

    BACKGROUND In observational studies, the relationship between blood pressure and end-stage renal disease (ESRD) is direct and progressive. The burden of hypertension-related chronic kidney disease and ESRD is especially high among black patients. Yet few trials have tested whether intensive blood-pressure control retards the progression of chronic kidney disease among black patients. METHODS We randomly assigned 1094 black patients with hypertensive chronic kidney disease to receive either intensive or standard blood-pressure control. After completing the trial phase, patients were invited to enroll in a cohort phase in which the blood-pressure target was less than 130/80 mm Hg. The primary clinical outcome in the cohort phase was the progression of chronic kidney disease, which was defined as a doubling of the serum creatinine level, a diagnosis of ESRD, or death. Follow-up ranged from 8.8 to 12.2 years. RESULTS During the trial phase, the mean blood pressure was 130/78 mm Hg in the intensive-control group and 141/86 mm Hg in the standard-control group. During the cohort phase, corresponding mean blood pressures were 131/78 mm Hg and 134/78 mm Hg. In both phases, there was no significant between-group difference in the risk of the primary outcome (hazard ratio in the intensive-control group, 0.91; P = 0.27). However, the effects differed according to the baseline level of proteinuria (P = 0.02 for interaction), with a potential benefit in patients with a protein-to-creatinine ratio of more than 0.22 (hazard ratio, 0.73; P = 0.01). CONCLUSIONS In overall analyses, intensive blood-pressure control had no effect on kidney disease progression. However, there may be differential effects of intensive blood-pressure control in patients with and those without baseline proteinuria. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases, the National Center on Minority Health and Health Disparities, and others.) PMID:20818902

  16. VENTILATION MODEL REPORT

    SciTech Connect

    V. Chipman

    2002-10-31

    The purpose of the Ventilation Model is to simulate the heat transfer processes in and around waste emplacement drifts during periods of forced ventilation. The model evaluates the effects of emplacement drift ventilation on the thermal conditions in the emplacement drifts and surrounding rock mass, and calculates the heat removal by ventilation as a measure of the viability of ventilation to delay the onset of peak repository temperature and reduce its magnitude. The heat removal by ventilation is temporally and spatially dependent, and is expressed as the fraction of heat carried away by the ventilation air compared to the fraction of heat produced by radionuclide decay. One minus the heat removal is called the wall heat fraction, or the remaining amount of heat that is transferred via conduction to the surrounding rock mass. Downstream models, such as the ''Multiscale Thermohydrologic Model'' (BSC 2001), use the wall heat fractions as outputted from the Ventilation Model to initialize their postclosure analyses.

  17. Possible pathogenic interplay between Chlamydia suis, Chlamydophila abortus and PCV-2 on a pig production farm.

    PubMed

    Schautteet, K; Beeckman, D S A; Delava, P; Vanrompay, D

    2010-03-13

    A concurrent outbreak of chlamydial disease in boars, sows and gilts and postweaning multisystemic wasting syndrome (PMWS) in weaned piglets was investigated on a large pig production farm in Estonia. Chlamydia suis DNA was detected in conjunctival swabs from boars, sows and gilts, but also in the faeces of boars and sows. Chlamydophila abortus DNA was found in semen, and in conjunctival swabs from sows; DNA was demonstrated by microarrays. Serum samples from boars were examined using a Chlamydiaceae-specific recombinant ELISA. All 10 serum samples examined were positive (1:960 to 1:3840). Chlamydiosis was characterised by reproductive failure and conjunctivitis. Piglets were not examined for Chlamydiaceae, as eye problems were not observed. Piglets showed wasting, respiratory signs, diarrhoea, enlargement of lymph nodes and increased mortality (10 per cent). Porcine circovirus type 2 (PCV-2) was detected in the lymph nodes of piglets by immunohistochemistry, and PCV-2 antibodies were demonstrated in all 10 serum samples from sows examined using an immunoperoxidase monolayer assay. PMID:20228367

  18. VENTILATION TECHNOLOGY SYSTEMS ANALYSIS

    EPA Science Inventory

    The report gives results of a project to develop a systems analysis of ventilation technology and provide a state-of-the-art assessment of ventilation and indoor air quality (IAQ) research needs. (NOTE: Ventilation technology is defined as the hardware necessary to bring outdoor ...

  19. Contaminants in Naturally Ventilated

    E-print Network

    Politècnica de Catalunya, Universitat

    a natural ventilation/flushing Volcanic Magma Chambers Deep Ocean Recirculation Basins Lakes Buildings (My;Displacement Ventilation An air distribution system in which incoming air originates at floor level and risesContaminants in Naturally Ventilated Closed Spaces Diogo Bolster #12;Outline Motivation Modelling

  20. A progress update for the pressure controlled atomization process

    SciTech Connect

    Tierney, J.C.; Glovan, R.J.

    1994-12-31

    Two engineering tests series were conducted to qualify the Pressure Controlled Atomization Process (PCAP) for use as a replacement for hard chromium electroplating as a means of refurbishing US Air Force aviation parts. The test series, Boeing and Wright Laboratory Test Series, were conducted on PCAP-coated specimens that were sprayed by MSE, Inc., and then tested by Boeing and the Wright Laboratory. Tests conducted included fatigue, abrasion, corrosion, adhesion, internal stress, chemistry, metallurgy, hardness, and materials compatibility and workability. In addition to the two test series, modifications to the spray system have been implemented to make the PCAP repeatable and controllable by a single operator. Modifications included installation of a vacuum/pressure spray chamber, design and installation of a new high temperature 1,800 C (3,272 F) inert gas heating system, and an automated tundish pressure control system to regulate the spray process. As the PCAP process has been refined, potential research and development applications have also been identified. These applications are well-suited to the characteristic narrow spray plume, low thermal input, and high deposition efficiency of the PCAP. Potential applications include development of a self-locking threaded fastener, development of anew method for rapid manufacturing of printed circuit boards, and possibly spraying ceramics as near-net shape components.

  1. Tank pressure control experiment on the space shuttle

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The tank pressure control experiment is a demonstration of NASA intent to develop new technology for low-gravity management of the cryogenic fluids that will be required for future space systems. The experiment will use freon as the test fluid to measure the effects of jet-induced fluid mixing on storage tank pressure and will produce data on low-gravity mixing processes critical to the design of on-orbit cryogenic storage and resupply systems. Basic data on fluid motion and thermodynamics in low gravity is limited, but such data is critical to the development of space transfer vehicles and spacecraft resupply facilities. An in-space experiment is needed to obtain reliable data on fluid mixing and pressure control because none of the available microgravity test facilities provide a low enough gravity level for a sufficient duration to duplicate in-space flow patterns and thermal processes. Normal gravity tests do not represent the fluid behavior properly; drop-tower tests are limited in length of time available; aircraft low-gravity tests cannot provide the steady near-zero gravity level and long duration needed to study the subtle processes expected in space.

  2. The comparison of manual and LabVIEW-based fuzzy control on mechanical ventilation.

    PubMed

    Guler, Hasan; Ata, Fikret

    2014-09-01

    The aim of this article is to develop a knowledge-based therapy for management of rats with respiratory distress. A mechanical ventilator was designed to achieve this aim. The designed ventilator is called an intelligent mechanical ventilator since fuzzy logic was used to control the pneumatic equipment according to the rat's status. LabVIEW software was used to control all equipments in the ventilator prototype and to monitor respiratory variables in the experiment. The designed ventilator can be controlled both manually and by fuzzy logic. Eight female Wistar-Albino rats were used to test the designed ventilator and to show the effectiveness of fuzzy control over manual control on pressure control ventilation mode. The anesthetized rats were first ventilated for 20 min manually. After that time, they were ventilated for 20 min by fuzzy logic. Student's t-test for p?ventilator and developed knowledge-based therapy support artificial respiration of living things successfully. PMID:25205667

  3. DEMAND CONTROLLED VENTILATION AND CLASSROOM VENTILATION

    SciTech Connect

    Fisk, William J.; Mendell, Mark J.; Davies, Molly; Eliseeva, Ekaterina; Faulkner, David; Hong, Tienzen; Sullivan, Douglas P.

    2014-01-06

    This document summarizes a research effort on demand controlled ventilation and classroom ventilation. The research on demand controlled ventilation included field studies and building energy modeling. Major findings included: ? The single-location carbon dioxide sensors widely used for demand controlled ventilation frequently have large errors and will fail to effectively control ventilation rates (VRs).? Multi-location carbon dioxide measurement systems with more expensive sensors connected to multi-location sampling systems may measure carbon dioxide more accurately.? Currently-available optical people counting systems work well much of the time but have large counting errors in some situations. ? In meeting rooms, measurements of carbon dioxide at return-air grilles appear to be a better choice than wall-mounted sensors.? In California, demand controlled ventilation in general office spaces is projected to save significant energy and be cost effective only if typical VRs without demand controlled ventilation are very high relative to VRs in codes. Based on the research, several recommendations were developed for demand controlled ventilation specifications in the California Title 24 Building Energy Efficiency Standards.The research on classroom ventilation collected data over two years on California elementary school classrooms to investigate associations between VRs and student illness absence (IA). Major findings included: ? Median classroom VRs in all studied climate zones were below the California guideline, and 40percent lower in portable than permanent buildings.? Overall, one additional L/s per person of VR was associated with 1.6percent less IA. ? Increasing average VRs in California K-12 classrooms from the current average to the required level is estimated to decrease IA by 3.4percent, increasing State attendance-based funding to school districts by $33M, with $6.2 M in increased energy costs. Further VR increases would provide additional benefits.? Confirming these findings in intervention studies is recommended. ? Energy costs of heating/cooling unoccupied classrooms statewide are modest, but a large portion occurs in relatively few classrooms.

  4. Prospective Evaluation of Subretinal Vessel Location in Polypoidal Choroidal Vasculopathy (PCV) and Response of Hemorrhagic and Exudative PCV to High-Dose Antiangiogenic Therapy (An American Ophthalmological Society Thesis)

    PubMed Central

    Kokame, Gregg T.

    2014-01-01

    Purpose: The purpose of this study was to determine the following: (1) Is polypoidal choroidal vasculopathy (PCV) a subretinal neovascular process, rather than a choroidal vascular anomaly? and (2) Is a higher dose of ranibizumab (2.0 mg/0.05 mL) more effective in treating PCV than the current dose (0.5 mg/0.05 mL) approved for treatment of age-related macular degeneration? Methods: Retrospective evaluation of PCV in 104 eyes of 86 patients was accomplished with use of indocyanine green angiography plus optical coherence tomography to localize the branching vascular network and the polyps. Nineteen eyes of 19 patients with active leaking and exudation underwent a prospective open-label trial of monthly high-dose intravitreal ranibizumab (2.0 mg/0.05 mL). The primary outcome was prevention of major vision loss (?15 ETDRS letters). Secondary outcomes included adverse events, improved vision, and changes in subretinal hemorrhage, subretinal fluid, macular edema, and polypoidal complexes at 6 months. Results: The PCV vessels were localized beneath the retinal pigment epithelium (RPE) and above Bruch’s membrane in 103 (99%) of 104 eyes. In the high-dose ranibizumab trial at 6 months, none of the patients lost ?15 letters in visual acuity, and 5 (26%) of 19 gained ?15 letters. Decreases were noted in subretinal fluid in 14 (82%) of 17 eyes, subretinal hemorrhage in 12 (100%) of 12, RPE detachment in 14 (88%) of 16, macular edema in 11 (92%) of 12, and polyps in 15 (79%) of 19 eyes. Conclusions: PCV vessels are a subtype of subretinal neovascularization located above Bruch’s membrane and below RPE. High-dose ranibizumab (2.0 mg/0.05 mL) decreased exudation and hemorrhage and resulted in significant polyp regression, although branching vascular networks persisted. PMID:25646029

  5. DIFFERENCE IN SEVERITY OF PORCINE CIRCOVIRUS TYPE 2 (PCV2)-INDUCED PATHOLOGICAL LESIONS AND DISEASE BETWEEN LANDRACE AND PIETRAIN PIGS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anecdotal information from pig producers and veterinarians in the field suggests that there are genetic differences in susceptibility to porcine circovirus type 2 (PCV2) associated disease (PCVAD) among Landrace and Pietrain breeds. The objective of this study was to determine if a difference exist...

  6. Ventilation Model Report

    SciTech Connect

    V. Chipman; J. Case

    2002-12-20

    The purpose of the Ventilation Model is to simulate the heat transfer processes in and around waste emplacement drifts during periods of forced ventilation. The model evaluates the effects of emplacement drift ventilation on the thermal conditions in the emplacement drifts and surrounding rock mass, and calculates the heat removal by ventilation as a measure of the viability of ventilation to delay the onset of peak repository temperature and reduce its magnitude. The heat removal by ventilation is temporally and spatially dependent, and is expressed as the fraction of heat carried away by the ventilation air compared to the fraction of heat produced by radionuclide decay. One minus the heat removal is called the wall heat fraction, or the remaining amount of heat that is transferred via conduction to the surrounding rock mass. Downstream models, such as the ''Multiscale Thermohydrologic Model'' (BSC 2001), use the wall heat fractions as outputted from the Ventilation Model to initialize their post-closure analyses. The Ventilation Model report was initially developed to analyze the effects of preclosure continuous ventilation in the Engineered Barrier System (EBS) emplacement drifts, and to provide heat removal data to support EBS design. Revision 00 of the Ventilation Model included documentation of the modeling results from the ANSYS-based heat transfer model. Revision 01 ICN 01 included the results of the unqualified software code MULTIFLUX to assess the influence of moisture on the ventilation efficiency. The purposes of Revision 02 of the Ventilation Model are: (1) To validate the conceptual model for preclosure ventilation of emplacement drifts and verify its numerical application in accordance with new procedural requirements as outlined in AP-SIII-10Q, Models (Section 7.0). (2) To satisfy technical issues posed in KTI agreement RDTME 3.14 (Reamer and Williams 2001a). Specifically to demonstrate, with respect to the ANSYS ventilation model, the adequacy of the discretization (Section 6.2.3.1), and the downstream applicability of the model results (i.e. wall heat fractions) to initialize post-closure thermal models (Section 6.6). (3) To satisfy the remainder of KTI agreement TEF 2.07 (Reamer and Williams 2001b). Specifically to provide the results of post-test ANSYS modeling of the Atlas Facility forced convection tests (Section 7.1.2). This portion of the model report also serves as a validation exercise per AP-SIII.10Q, Models, for the ANSYS ventilation model. (4) To asses the impacts of moisture on the ventilation efficiency.

  7. Protective garment ventilation system

    NASA Technical Reports Server (NTRS)

    Lang, R. (inventor)

    1970-01-01

    A method and apparatus for ventilating a protective garment, space suit system, and/or pressure suits to maintain a comfortable and nontoxic atmosphere within is described. The direction of flow of a ventilating and purging gas in portions of the garment may be reversed in order to compensate for changes in environment and activity of the wearer. The entire flow of the ventilating gas can also be directed first to the helmet associated with the garment.

  8. Tank Pressure Control Experiment: Thermal Phenomena in Microgravity

    NASA Technical Reports Server (NTRS)

    Hasan, Mohammad M.; Lin, Chin S.; Knoll, Richard H.; Bentz, Michael D.

    1996-01-01

    The report presents the results of the flight experiment Tank Pressure Control Experiment/Thermal Phenomena (TPCE/TP) performed in the microgravity environment of the space shuttle. TPCE/TP, flown on the Space Transportation System STS-52, was a second flight of the Tank Pressure Control Experiment (TPCE). The experiment used Freon 113 at near saturation conditions. The test tank was filled with liquid to about 83% by volume. The experiment consisted of 21 tests. Each test generally started with a heating phase to increase the tank pressure and to develop temperature stratification in the fluid, followed by a fluid mixing phase for the tank pressure reduction and fluid temperature equilibration. The heating phase provided pool boiling data from large (relative to bubble sizes) heating surfaces (0.1046 m by 0.0742 m) at low heat fluxes (0.23 to 1.16 kW/sq m). The system pressure and the bulk liquid subcooling varied from 39 to 78 kPa and 1 to 3 C, respectively. The boiling process during the entire heating period, as well as the jet-induced mixing process for the first 2 min of the mixing period, was also recorded on video. The unique features of the experimental results are the sustainability of high liquid superheats for long periods and the occurrence of explosive boiling at low heat fluxes (0.86 to 1.1 kW/sq m). For a heat flux of 0.97 kW/sq m, a wall superheat of 17.9 C was attained in 10 min of heating. This superheat was followed by an explosive boiling accompanied by a pressure spike of about 38% of the tank pressure at the inception of boiling. However, at this heat flux the vapor blanketing the heating surface could not be sustained. Steady nucleate boiling continued after the explosive boiling. The jet-induced fluid mixing results were obtained for jet Reynolds numbers of 1900 to 8000 and Weber numbers of 0.2 to 6.5. Analyses of data from the two flight experiments (TPCE and TPCE/TP) and their comparison with the results obtained in drop tower experiments suggest that as Bond number approaches zero the flow pattern produced by an axial jet and the mixing time can be predicted by the Weber number.

  9. A Pressure Control Method for Emulsion Pump Station Based on Elman Neural Network

    PubMed Central

    Tan, Chao; Qi, Nan; Yao, Xingang; Wang, Zhongbin; Si, Lei

    2015-01-01

    In order to realize pressure control of emulsion pump station which is key equipment of coal mine in the safety production, the control requirements were analyzed and a pressure control method based on Elman neural network was proposed. The key techniques such as system framework, pressure prediction model, pressure control model, and the flowchart of proposed approach were presented. Finally, a simulation example was carried out and comparison results indicated that the proposed approach was feasible and efficient and outperformed others. PMID:25861253

  10. Exposure to environmental stressors result in increased viral load and further reduction of production parameters in pigs experimentally infected with PCV2b

    PubMed Central

    Patterson, Robert; Nevel, Amanda; Diaz, Adriana V.; Martineau, Henny M.; Demmers, Theo; Browne, Christopher; Mavrommatis, Bettina; Werling, Dirk

    2015-01-01

    Porcine circovirus type 2 (PCV2) has been identified as the essential, but not sole, underlying infectious component for PCV-associated diseases (PCVAD). Several co-factors have been suggested to convert an infection with PCV2 into the clinical signs of PCVAD, including co-infection with a secondary pathogen and the genetic background of the pig. In the present study, we investigated the role of environmental stressors in the form of changes in environmental temperature and increased stocking-density on viral load in serum and tissue, average daily weight gain (ADG) and food conversion rate (FCR) of pigs experimentally infected with a defined PCV2b strain over an eight week period. These stressors were identified recently as risk factors leading to the occurrence of severe PCVAD on a farm level. In the current study, PCV2-free pigs were housed in separate, environmentally controlled rooms, and the experiment was performed in a 2 × 2 factorial design. In general, PCV2b infection reduced ADG and increased FCR, and these were further impacted on by the environmental stressors. Furthermore, all stressors led to an increased viral load in serum and tissue as assessed by qPCR, although levels did not reach statistical significance. Our data suggest that there is no need for an additional pathogen to develop PCVAD in conventional status pigs, and growth retardation and clinical signs can be induced in PCV2 infected pigs that are exposed to environmental stressors alone. PMID:25866129

  11. Review of Residential Ventilation Technologies

    SciTech Connect

    Armin Rudd

    2005-08-30

    This paper reviews current and potential ventilation technologies for residential buildings, including a variety of mechanical systems, natural ventilation, and passive ventilation. with particular emphasis on North American climates and construction.

  12. Pulmonary ventilation/perfusion scan

    MedlinePLUS

    V/Q scan; Ventilation/perfusion scan; Lung ventilation/perfusion scan ... A pulmonary ventilation/perfusion scan is actually two tests. They may be done separately or together. During the perfusion scan, a ...

  13. Piezoelectric MEMS array package for distributed CMP pressure control

    NASA Astrophysics Data System (ADS)

    Mayyas, Mohammad

    2015-06-01

    In this paper we develop an array of pressure control units that locally and selectively pressurizes the wafer for better uniformity of thickness removal during the chemical mechanical planarization (CMP) process. A real-time metrology measurement determines where on the wafer the microactuator array should be activated in order to improve the overall uniformity of the wafer surface. We developed a new micro surface actuation mechanism comprising an array of piezoelectric bending discs sandwiched in a single multi-layer package. We obtained scalable manufacturing and packaging methods that do not only reduce the mechanical misalignment tolerances of such arrays, but also improve their electrical interconnect reliability under harsh environments. The finite element models showed that an individual disc in the array can generate local contact pressure. CMP experiments showed that such locality controlled the material removal rate on silicon wafer. A microactuator unit in an array delivered precise displacement and large pressure outputs measured for a wide range of input voltages. The static and dynamic responses of the microactuator were linear, and had a fast response to voltage input, making it suitable for high speed distributed pressure compensation during the CMP process.

  14. Tank pressure control in low gravity by jet mixing

    NASA Technical Reports Server (NTRS)

    Bentz, Michael D.

    1993-01-01

    The Tank Pressure Control Experiment (TPCE) is a space experiment developed to help meet the need for a critical aspect of cryogenic fluid management technology: control of storage tank pressures in the absence of gravity by forced convective mixing. The experiment used a 13.7-liter tank filled to a constant 83 percent level with refrigerant 113 at near saturation conditions to simulate the fluid dynamics and thermodynamics of cryogenic fluids in space applications. The objectives of TPCE were to characterize the fluid dynamics of axial jet-induced mixing in low gravity, to evaluate the validity of empirical mixing models, and to provide data for use in developing and validating computational fluid dynamic models of mixing processes. TPCE accomplished all of its objectives in flight on Space Shuttle Mission STS-3 in August of 1991. The range of flow patterns photographed generally confirmed a prior correlation based on drop tower tests. A closed-form equation derived from a simple thermodynamic model was found to provide a first-order prediction of the pressure reduction time as a function of mixer parameters, tank size, and fluid thermophysical properties. Low energy mixing jets were found to be effective and reliable at reducing thermal non-uniformities, promoting heat and mass transfer between the phases, and reducing tank pressure.

  15. Multifamily Ventilation Retrofit Strategies

    SciTech Connect

    Ueno, K.; Lstiburek, J.; Bergey, D.

    2012-12-01

    In multifamily buildings, central ventilation systems often have poor performance, overventilating some portions of the building (causing excess energy use), while simultaneously underventilating other portions (causing diminished indoor air quality). BSC and Innova Services Corporation performed a series of field tests at a mid-rise test building undergoing a major energy audit and retrofit, which included ventilation system upgrades.

  16. Guide to Home Ventilation

    SciTech Connect

    2010-10-01

    A fact sheet from the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy: Ventilation refers to the exchange of indoor and outdoor air. Without proper ventilation, an otherwise insulated and airtight house will seal in harmful pollutants, such as carbon monoxide, and moisture that can damage a house.

  17. Home Ventilator Guide

    MedlinePLUS

    ... High FiO 2 , Ventilation not started/stopped, Circuit fault, Low/High PEEP, Pressure line disconnected H, O ... High FiO 2 , Ventilation not started/stopped, Circuit fault, Low/High PEEP, Pressure line disconnected H, O ...

  18. Vaccination with a Porcine Reproductive and Respiratory Syndrome (PRRS) Modified Live Virus Vaccine Followed by Challenge with PRRS Virus and Porcine Circovirus Type 2 (PCV2) Protects against PRRS but Enhances PCV2 Replication and Pathogenesis Compared to Results for Nonvaccinated Cochallenged Controls.

    PubMed

    Niederwerder, Megan C; Bawa, Bhupinder; Serão, Nick V L; Trible, Benjamin R; Kerrigan, Maureen A; Lunney, Joan K; Dekkers, Jack C M; Rowland, Raymond R R

    2015-12-01

    Coinfections involving porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) contribute to a group of disease syndromes known as porcine circovirus-associated disease (PCVAD). Presumably, PRRSV infection enhances PCV2 replication as a result of modulation of host immunity. The purpose of this study was to evaluate PCV2 replication and pathogenesis in pigs vaccinated with a PRRS modified live virus (MLV) vaccine and subsequently challenged with a combination of PRRSV and PCV2. During the early postchallenge period, the number of pigs with PRRSV-associated clinical signs was decreased, and average daily gain (ADG) was increased, in the vaccinated group, demonstrating the protective effect of PRRS vaccination. However, during the later postchallenge period, more pigs in the vaccinated group showed increased PCV2 viremia, decreased ADG, increased PCVAD clinical signs, and increased mortality. In this disease model, the early benefits of PRRSV vaccination were outweighed by the later amplification of PCVAD. PMID:26446422

  19. Blood pressure control to prevent decline in cognition after stroke

    PubMed Central

    Ihle-Hansen, Hege; Thommessen, Bente; Fagerland, Morten W; Øksengård, Anne R; Wyller, Torgeir B; Engedal, Knut; Fure, Brynjar

    2015-01-01

    Background Treatment of hypertension post-stroke preserves cognition through prevention of recurrent stroke, but it is not clear whether it prevents cognitive decline through other mechanisms. We aimed to describe changes in blood pressure from baseline to 1 year post-stroke and to evaluate the association between achieved blood pressure targets and cognitive function, mild cognitive impairment (MCI), and dementia. Methods We included patients with first-ever stroke, and defined achieved blood pressure goals as systolic blood pressure (SBP) in the categories ?125 mmHg, ?140 mmHg, and ?160 mmHg, SBP reduction of ?10 mmHg, and diastolic blood pressure (DBP) reduction of ?5 mmHg. The main outcome variables were cognitive assessments 1 year post stroke. Secondary outcomes were diagnoses of MCI or dementia. Results Forty-one of 166 patients (25%) reached SBP ?125 mmHg after 1 year, 92/166 (55%) reached SBP ?140 mmHg, and 150/166 (90%) reached SBP ?160 mmHg. SBP was reduced by ?10 mmHg in 44/150 (29%) and DBP by ?5 mmHg in 57/150 (38%). We did not find any statistically significant associations between cognitive test performances and different blood pressure goals (P=0.070–1.0). Nor was there any significant association between achieved goal blood pressure or blood pressure reduction after 1 year and the diagnoses of MCI or dementia (P=0.32–0.56). Conclusion Treatment of hypertension is important for primary and secondary prevention of stroke. Showing a potential beneficial effect of blood pressure control on cognitive function, however, probably needs longer follow-up. PMID:26089677

  20. Adequate pneumococcal prophylaxis continues to be a moving target.1,2 Introduction of Prevnar (PCV7, Wyeth Lederle Vaccines, Madison, NJ), a 7-serotype

    E-print Network

    Nicholson, Bruce J.

    polysaccharides from the 23 most prevalent and invasive types of Streptococcus pneumoniae including the serotypes, bronchitis and pneumonia due to Streptococcus pneumoniae. Increasing prevalence of non-PCV7 pneumococcal

  1. Instability in vitro of a PCV2 infectious clone containing an insertion between ORF1 and ORF2.

    PubMed

    Saha, Dipongkor; Doorsselaere, Jan V; Nauwynck, Hans J

    2012-04-01

    Porcine circovirus 2 (PCV2) is a small circular single-stranded DNA virus that causes postweaning multisystemic wasting syndrome in pigs. We obtained an infectious clone, derived from PCV2 strain 1147 (size 1,767 bp), with a 60 bp insertion in the cap-rep intergenic region at the 3' end of the rep. In vitro propagation and sequencing of virus showed mixed sequence for the cap-rep intergenic region. Cloning of this region of virus from the passages 2 and 20 showed deletions of various size of the 60 bp insertion. Viruses from the passage 20 showed deletions of the 60 bp insertion and had extra (+1 to +5) or less (-1 or -2) bp in the intergenic region as compared to 1,147. These findings suggest that insertion of a 60-bp DNA sequence at the 3' end of the rep is unstable in vitro. This finding can have implications for the genetic engineering of PCV2. PMID:22116682

  2. [A case of ventilation disorder and poor oxygenation after changing position from prone to supine].

    PubMed

    Yamaguchi, Satoshi; Hirakawa, Kei; Kitamura, Jiro

    2013-01-01

    A 68-year-old obese woman (BMI 35) underwent posterior lumbar interbody fusion in prone position. Immediately after changing position postoperatively from prone to supine, severe ventilation disorder and poor oxygenation occured. Chest X-ray showed severe atelectasis. Poor oxygenation was suspected to be the result of the atelectasis by the pressure of massive abdominal fatty tissue to the diaphragm. Ventilation disorder was suspected of the bronchospasm associated with inadequate anesthesia. We ventilated her manually with a bag in Fowler position for twenty minutes, and then mechanically by pressure controlled ventilation. She recovered gradually. It is concluded that in obese patients undergoing operation in prone position, changing position should be done very carefully during adequate anesthesia, understanding respiratory physiology in positioning and considering the effect of the abdominal fatty tissue to the diaphragm. PMID:23431901

  3. Lung Ventilation/Perfusion Scan

    MedlinePLUS

    ... the NHLBI on Twitter. What Is a Lung Ventilation/Perfusion Scan? A lung ventilation/perfusion scan, or VQ scan, is a test ... A VQ scan involves two types of scans: ventilation and perfusion. The ventilation scan shows where air ...

  4. Ventilating Air-Conditioner

    NASA Technical Reports Server (NTRS)

    Dinh, Khanh

    1994-01-01

    Air-conditioner provides ventilation designed to be used alone or incorporated into cooling or heating system operates efficiently only by recirculating stale air within building. Energy needed to operate overall ventilating cooling or heating system slightly greater than operating nonventilating cooling or heating system. Helps to preserve energy efficiency while satisfying need for increased forced ventilation to prevent accumulation of undesired gases like radon and formaldehyde. Provides fresh treated air to variety of confined spaces: hospital surgeries, laboratories, clean rooms, and printing shops and other places where solvents used. In mobile homes and portable classrooms, eliminates irritant chemicals exuded by carpets, panels, and other materials, ensuring healthy indoor environment for occupants.

  5. Production of inflammatory cytokines in response to diphtheria-pertussis-tetanus (DPT), haemophilus influenzae type b (Hib), and 7-valent pneumococcal (PCV7) vaccines

    PubMed Central

    Kashiwagi, Yasuyo; Miyata, Akiko; Kumagai, Takuji; Maehara, Kouji; Suzuki, Eitarou; Nagai, Takao; Ozaki, Takao; Nishimura, Naoko; Okada, Kenji; Kawashima, Hisashi; Nakayama, Tetsuo

    2014-01-01

    Haemophilus influenzae type b (Hib) and 7-valent pneumococcal (PCV7) vaccines both became recommended in Japan in 2010. In this study, cytokine production was investigated in peripheral blood mononuclear cells (PBMCs) cultures stimulated with diphtheria and tetanus toxoids combined with acellular pertussis vaccine (DPT), Hib, and PCV7 separately or concurrent different combinations, all as final off-the-shelf vaccines without the individual vaccine components as controls. Higher IL-1? levels were produced when cultures were stimulated with PCV than with DPT or Hib, and the concurrent stimulation including PCV7 enhanced the production of IL-1?. Although Hib induced higher levels of IL-6, no significant difference was observed in IL-6 production with the concurrent stimulation. The concurrent stimulation with Hib/PCV7 and DPT/Hib/PCV7 produced higher levels of TNF-? and human G-CSF. Cytokine profiles were examined in serum samples obtained from 61 vaccine recipients with febrile reactions and 18 recipients without febrile illness within 24 h of vaccination. No significant difference was observed in cytokine levels of IL-1?, IL-4, IL-6, IL-10, IL-12, IFN-?, MIP-1, TNF-?, and prostaglandin E2 (PGE2) in sera between the two groups. However, significantly higher levels of human G-CSF were observed in recipients with febrile illness than in those without febrile reactions. Further investigations of the significance of elevated serum G-CSF levels are required in vaccine recipients with febrile illness. PMID:24589970

  6. Pressure Control System Design for a Closed Crop Growth Chamber

    NASA Technical Reports Server (NTRS)

    Tsai, K.; Blackwell, C.; Harper, Lynn D. (Technical Monitor)

    1994-01-01

    The Controlled Ecological Life Support System (CELSS) is an area of active research at NASA. CELSS is a plant-based bioregenerative life support system for long term manned space flights where resupply is costly or impractical. The plants in a CELSS will function to convert the carbon dioxide (exhaled by the crew) into oxygen, purify non-potable water into potable quality water, and provide food for the crew. Prior to implementing a CELSS life support system, one must have knowledge on growing plants in a closed chamber under low gravity. This information will come from research to be conducted on the CELSS Test Facility that will operate on the Space Station Freedom. Currently a ground-based CELSS Test Facility is being built at NASA Ames Research Center. It is called the EDU (Engineering Development Unit). This system will allow researchers to identify issues that may cause difficulties in the development of the CELSS Test Facility and aid in the development of new needed technologies. The EDU consists of a 1 m2 crop growth chamber that is surrounded by a containment enclosure. The containment enclosure isolates the system so there is very little mass and thermal exchange with the ambient. The leakage rate is on the order of 1 % of the enclosure's volume per day (with 0.2S psi pressure difference). The thermal leakage is less than 0.5% of the electrical power supplied to the system per degree Celsius difference from the surrounding. The pressure in the containment enclosure is regulated at 62.5 Pa below the ambient by an active controller. The goal is to maintain this set point for a variety of conditions, such as a range of operating temperatures, heat load variations that occur when the lights are turned on and off, and fluctuations in ambient pressure. In addition certain transition tracking performance is required. This paper illustrates the application of some advanced systems control methods to the task of synthesizing the EDU's pressure control system.

  7. Why We Ventilate

    SciTech Connect

    Logue, Jennifer M.; Sherman, Max H.; Price, Phil N.; Singer, Brett C.

    2011-09-01

    It is widely accepted that ventilation is critical for providing good indoor air quality (IAQ) in homes. However, the definition of"good" IAQ, and the most effective, energy efficient methods for delivering it are still matters of research and debate. This paper presents the results of work done at the Lawrence Berkeley National Lab to identify the air pollutants that drive the need for ventilation as part of a larger effort to develop a health-based ventilation standard. First, we present results of a hazard analysis that identified the pollutants that most commonly reach concentrations in homes that exceed health-based standards or guidelines for chronic or acute exposures. Second, we present results of an impact assessment that identified the air pollutants that cause the most harm to the U.S. population from chronic inhalation in residences. Lastly, we describe the implications of our findings for developing effective ventilation standards.

  8. NINTH INTERIM STATUS REPORT: MODEL 9975 PCV O-RING FIXTURE LONG-TERM LEAK PERFORMANCE

    SciTech Connect

    Daugherty, W.

    2014-08-06

    A series of experiments to monitor the aging performance of Viton® GLT O-rings used in the Model 9975 package has been ongoing since 2004 at the Savannah River National Laboratory. One approach has been to periodically evaluate the leak performance of O-rings being aged in mock-up 9975 Primary Containment Vessels (PCVs) at elevated temperatures. Other methods such as compression-stress relaxation (CSR) tests and field surveillance are also on-going to evaluate O-ring behavior. Seventy tests using PCV mock-ups were assembled and heated to temperatures ranging from 200 to 450 ºF. They were leak-tested initially and have been tested periodically to determine if they continue to meet the leak-tightness criterion defined in ANSI standard N14.5-97. Due to material substitution, fourteen additional tests were initiated in 2008 with GLT-S O-rings heated to temperatures ranging from 200 to 400 ºF. High temperature aging continues for 23 GLT O-ring fixtures at 200 – 270 ºF. Room temperature leak test failures have been experienced in all of the GLT O-ring fixtures aging at 350 ºF and higher temperatures, and in 8 fixtures aging at 300 ºF. The earliest 300 °F GLT O-ring fixture failure was observed at 34 months. The remaining GLT O-ring fixtures aging at 300 ºF have been retired from testing following more than 5 years at temperature without failure. No failures have yet been observed in GLT O-ring fixtures aging at 200 ºF for 72 - 96 months, which bounds O-ring temperatures anticipated during storage in K-Area Complex (KAC). Based on expectations that the 200 ºF fixtures will remain leak-tight for a significant period yet to come, 2 additional fixtures began aging in 2011 at 270 ºF, with hopes that they may reach a failure condition before the 200 ºF fixtures, thus providing additional time to failure data. High temperature aging continues for 6 GLT-S O-ring fixtures at 200 – 300 ºF. Room temperature leak test failures have been experienced in all 8 of the GLT-S O-ring fixtures aging at 350 and 400 ºF. No failures have yet been observed in GLT-S O-ring fixtures aging at 200 - 300 ºF for 54 - 57 months. No additional O-ring failures have been observed since the last interim report was issued. Aging and periodic leak testing will continue for the remaining PCV fixtures. Additional irradiation of several fixtures is recommended to maintain a balance between thermal and radiation exposures similar to that experienced in storage, and to show the degree of consistency of radiation response between GLT and GLT-S O-rings.

  9. Role of Chinese herbal medicinal ingredients in secretion of cytokines by PCV2-induced endothelial cells.

    PubMed

    Hu, Yiyi; He, Kongwang; Wang, Xiaomin

    2016-03-01

    While T-lymphocytes are the major cell type responsible for host responses to a virus (including induction of inflammatory responses to aid in ultimate removal of virus), other cells, including macrophages, epithelial and dendritic cells also have key roles. Endothelial cells also play important roles in physiologic/pathologic processes, like inflammation, during viral infections. As endothelial cells can be activated to release various endogenous compounds, including some cytokines, ex vivo measures of cytokine formation by the cells can be used to indirectly assess any potential endothelial dysfunction in situ. The research presented here sought to investigate potential immunolomodulatory effects of five saponins on endothelial cells: Saikosaponins A (SSA) and D (SSD), Panax Notoginseng Saponin (PNS) and Notoginsenoside R1 (SR1) and Anemoside B4 (AB4). For this, cells (porcine iliac artery endothelial line) were challenged with a virus isolate PCV2-AH for 24?h and then treated with the test saponin (at 1, 5 or 10??g/ml) for an additional 24?h at 37?°C. The culture supernatants were then collected and analyzed for interleukin (IL)-2, -4 and -10, as well as interferon (IFN)-? by ELISA. The results revealed that PNS and SR1 inhibited the production of IL-4; PNS, SR1 and AB4 inhibited the secretion of IL-10; SSA, SSD and PNS up-regulated IL-2 expression; SSA and SSD increased the level of IFN?. All these changes were significant. Taken together, the data suggested these saponins might potentially have a capacity to regulate immune responses in vivo via changes in production of these select cytokines by infected endothelial cells. Nevertheless, the impact of these agents on other key cell types involved in anti-viral responses, including T-lymphocytes, remains to be determined. PMID:25721049

  10. Conventional mechanical ventilation

    PubMed Central

    Tobias, Joseph D.

    2010-01-01

    The provision of mechanical ventilation for the support of infants and children with respiratory failure or insufficiency is one of the most common techniques that are performed in the Pediatric Intensive Care Unit (PICU). Despite its widespread application in the PICUs of the 21st century, before the 1930s, respiratory failure was uniformly fatal due to the lack of equipment and techniques for airway management and ventilatory support. The operating rooms of the 1950s and 1960s provided the arena for the development of the manual skills and the refinement of the equipment needed for airway management, which subsequently led to the more widespread use of endotracheal intubation thereby ushering in the era of positive pressure ventilation. Although there seems to be an ever increasing complexity in the techniques of mechanical ventilation, its successful use in the PICU should be guided by the basic principles of gas exchange and the physiology of respiratory function. With an understanding of these key concepts and the use of basic concepts of mechanical ventilation, this technique can be successfully applied in both the PICU and the operating room. This article reviews the basic physiology of gas exchange, principles of pulmonary physiology, and the concepts of mechanical ventilation to provide an overview of the knowledge required for the provision of conventional mechanical ventilation in various clinical arenas. PMID:20927268

  11. 14 CFR 25.831 - Ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Ventilation and Heating § 25.831 Ventilation... probable failures or malfunctioning of the ventilating, heating, pressurization, or other systems...

  12. 14 CFR 25.831 - Ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Ventilation and Heating § 25.831 Ventilation... probable failures or malfunctioning of the ventilating, heating, pressurization, or other systems...

  13. 14 CFR 25.831 - Ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Ventilation and Heating § 25.831 Ventilation... probable failures or malfunctioning of the ventilating, heating, pressurization, or other systems...

  14. 14 CFR 25.831 - Ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Ventilation and Heating § 25.831 Ventilation... probable failures or malfunctioning of the ventilating, heating, pressurization, or other systems...

  15. 14 CFR 25.831 - Ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Ventilation and Heating § 25.831 Ventilation... probable failures or malfunctioning of the ventilating, heating, pressurization, or other systems...

  16. Lack of effect of piglet vaccination against Porcine circovirus type 2 (PCV2) on serum viral loads of Torque teno sus virus 2 (TTSuV2).

    PubMed

    Nieto, D; Aramouni, M; Sibila, M; Fraile, L; Kekarainen, T; Segalés, J

    2012-05-25

    Anelloviruses are small, non-enveloped viruses with circular single stranded DNA, which infect a number of animal species as well as humans. In pigs, two distinct Torque teno sus virus (TTSuV) species have been described so far, being one of them linked to disease occurrence. Specifically, TTSuV2 loads in serum have been found increased in pigs suffering from postweaning multisystemic wasting syndrome (PMWS). Since this pathological condition is able to be controlled by means of porcine circovirus type 2 (PCV2) vaccination, it was hypothesized the possibility that such vaccination would have an impact on TTSuV2 prevalence and loads. A total of 150 pigs were divided in two study groups. Half of them received a PCV2 commercial vaccine, while the other half remained as non-vaccinated controls. PCV2 infection was monitored at 3-4, 8, 12, 16 and 21 weeks of age by means of an standard PCR, while TTSuV2 loads were determined at 8, 16 and 21 weeks of age by a quantitative PCR. No obvious PMWS clinical signs were observed among studied animals, although PCV2 infection was confirmed in both groups of pigs. Almost all pigs got TTSuV2 infection throughout the study period, independently of the PCV2 vaccination status of animals. Moreover, TTSuV2 load did not show significant differences between different pig groups at each sampling time, but mean viral load increased with age. Taking into account that previous results suggest that TTSuV2 load in serum is increased in the background of PMWS, the present study suggests that this is not the case in a PCV2 subclinical infection scenario. Therefore, vaccination of PCV2 subclinically infected pigs did not modify the outcome of TTSuV2 infection. PMID:22189433

  17. Nursing Education in High Blood Pressure Control. Report of the Task Force on the Role of Nursing in High Blood Pressure Control.

    ERIC Educational Resources Information Center

    National Institutes of Health (DHEW), Bethesda, MD. High Blood Pressure Information Center.

    This curriculum guide on high blood pressure (hypertension) for nursing educators has five sections: (1) Introduction and Objectives provides information regarding the establishment and objectives of the National Task Force on the Role of Nursing in High Blood Pressure Control and briefly discusses nursing's role in hypertension control; (2) Goals…

  18. Increased Natural Ventilation Flow Rates through Ventilation Shafts

    E-print Network

    Ray, Stephen D.

    Buoyancy-driven natural ventilation in ventilation shafts is investigated with a small scale physical experiment within a duct and CFD simulations of an office building. For a fixed exhaust opening, smaller shafts lead to ...

  19. Impact of routine PCV7 (Prevenar) vaccination of infants on the clinical and economic burden of pneumococcal disease in Malaysia

    PubMed Central

    2011-01-01

    Background Pneumococcal disease is the leading cause of vaccine-preventable death in children younger than 5 years of age worldwide. The World Health Organization recommends pneumococcal conjugate vaccine as a priority for inclusion into national childhood immunization programmes. Pneumococcal vaccine has yet to be included as part of the national vaccination programme in Malaysia although it has been available in the country since 2005. This study sought to estimate the disease burden of pneumococcal disease in Malaysia and to assess the cost effectiveness of routine infant vaccination with PCV7. Methods A decision model was adapted taking into consideration prevalence, disease burden, treatment costs and outcomes for pneumococcal disease severe enough to result in a hospital admission. Disease burden were estimated from the medical records of 6 hospitals. Where local data was unavailable, model inputs were obtained from international and regional studies and from focus group discussions. The model incorporated the effects of herd protection on the unvaccinated adult population. Results At current vaccine prices, PCV7 vaccination of 90% of a hypothetical 550,000 birth cohort would incur costs of RM 439.6 million (US$128 million). Over a 10 year time horizon, vaccination would reduce episodes of pneumococcal hospitalisation by 9,585 cases to 73,845 hospitalisations with cost savings of RM 37.5 million (US$10.9 million) to the health system with 11,422.5 life years saved at a cost effectiveness ratio of RM 35,196 (US$10,261) per life year gained. Conclusions PCV7 vaccination of infants is expected to be cost-effective for Malaysia with an incremental cost per life year gained of RM 35,196 (US$10,261). This is well below the WHO's threshold for cost effectiveness of public health interventions in Malaysia of RM 71,761 (US$20,922). PMID:21936928

  20. EIGHTH INTERIM STATUS REPORT: MODEL 9975 PCV O-RING FIXTURE LONG-TERM LEAK PERFORMANCE

    SciTech Connect

    Daugherty, W. L.

    2013-09-03

    A series of experiments to monitor the aging performance of Viton® GLT O-rings used in the Model 9975 package has been ongoing since 2004 at the Savannah River National Laboratory. Seventy tests using mock-ups of 9975 Primary Containment Vessels (PCVs) were assembled and heated to temperatures ranging from 200 to 450 ºF. They were leak-tested initially and have been tested periodically to determine if they meet the criterion of leak-tightness defined in ANSI standard N14.5-97. Fourteen additional tests were initiated in 2008 with GLT-S O-rings heated to temperatures ranging from 200 to 400 ºF. High temperature aging continues for 23 GLT O-ring fixtures at 200 – 270 ºF. Room temperature leak test failures have been experienced in all of the GLT O-ring fixtures aging at 350 ºF and higher temperatures, and in 8 fixtures aging at 300 ºF. The remaining GLT O-ring fixtures aging at 300 ºF have been retired from testing following more than 5 years at temperature without failure. No failures have yet been observed in GLT O-ring fixtures aging at 200 ºF for 61 - 85 months, which is still bounding to O-ring temperatures during storage in KArea Complex (KAC). Based on expectations that the fixtures aging at 200 ºF will remain leaktight for a significant period yet to come, 2 additional fixtures began aging in 2011 at an intermediate temperature of 270 ºF, with hopes that they may reach a failure condition before the 200 ºF fixtures. High temperature aging continues for 6 GLT-S O-ring fixtures at 200 – 300 ºF. Room temperature leak test failures have been experienced in all 8 of the GLT-S O-ring fixtures aging at 350 and 400 ºF. No failures have yet been observed in GLT-S O-ring fixtures aging at 200 - 300 ºF for 41 - 45 months. Aging and periodic leak testing will continue for the remaining PCV fixtures.

  1. Meeting Residential Ventilation Standards Through Dynamic Control of Ventilation Systems

    SciTech Connect

    Sherman, Max H.; Walker, Iain S.

    2011-04-01

    Existing ventilation standards, including American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) Standard 62.2, specify continuous operation of a defined mechanical ventilation system to provide minimum ventilation, with time-based intermittent operation as an option. This requirement ignores several factors and concerns including: other equipment such as household exhaust fans that might incidentally provide ventilation, negative impacts of ventilation when outdoor pollutant levels are high, the importance of minimizing energy use particularly during times of peak electricity demand, and how the energy used to condition air as part of ventilation system operation changes with outdoor conditions. Dynamic control of ventilation systems can provide ventilation equivalent to or better than what is required by standards while minimizing energy costs and can also add value by shifting load during peak times and reducing intake of outdoor air contaminants. This article describes the logic that enables dynamic control of whole-house ventilation systems to meet the intent of ventilation standards and demonstrates the dynamic ventilation system control concept through simulations and field tests of the Residential Integrated Ventilation-Energy Controller (RIVEC).

  2. Ventilation technologies scoping study

    SciTech Connect

    Walker, Iain S.; Sherman, Max H.

    2003-09-30

    This document presents the findings of a scoping study commissioned by the Public Interest Energy Research (PIER) program of the California Energy Commission to determine what research is necessary to develop new residential ventilation requirements for California. This study is one of three companion efforts needed to complete the job of determining the needs of California, determining residential ventilation requirements, and determining appropriate ventilation technologies to meet these needs and requirements in an energy efficient manner. Rather than providing research results, this scoping study identifies important research questions along with the level of effort necessary to address these questions and the costs, risks, and benefits of pursuing alternative research questions. In approaching these questions and level of effort, feasibility and timing were important considerations. The Commission has specified Summer 2005 as the latest date for completing this research in time to update the 2008 version of California's Energy Code (Title 24).

  3. Non invasive ventilation.

    PubMed

    Sidhu, U S; Simonds, A K

    2000-04-01

    Non-invasive ventilation refers to the technique of providing ventilatory support to a patient without an endo/orotracheal airway. It is a promising and rapidly upcoming new technique and is being used as first line therapy in a wide variety of conditions causing respiratory failure. The major indications for its use include respiratory failure due to a variety of causes (chest wall abnormalities, neuromuscular disease, COPD), weaning and stabilization of cardio-respiratory status before and after surgery. Patients who are candidates for this modality usually have a hypercapnic respiratory failure but are able to protect the airway and cooperate with treatment. The biggest advantage of the technique is its simplicity and avoidance of complications of intubation like trauma, infection and delayed complications like tracheal stenosis. Patient comfort is significantly improved and important functions like speech, swallowing and cough are preserved. Several purpose built ventilators are available for use including pressure preset and volume present machines, each of which have their own advantages and disadvantages in clinical practice. A range of patient interfaces is available. The initiation of non-invasive ventilation is much easier as compared to invasive ventilation and can be done for most patients in an intermediary care unit thereby cutting down treatment costs and saving precious intensive care beds. Titration of ventilatory parameters can usually be done using simple tests like oxymetry and blood gases. Several technique related problems like skin pressure sores, nasal symptoms and abdominal distension can be managed with simple measures. Non invasive ventilation has got a special and evolving role in management of COPD, both in acute exacerbations and chronic respiratory failure. In short, the advantages of this form of ventilation are numerous and physicians must familiarize themselves with this new technique, facilities for which should be available in all hospitals admitting patients with respiratory failure. PMID:11273177

  4. Natural ventilation generates building form

    E-print Network

    Chen, Shaw-Bing

    1996-01-01

    Natural ventilation is an efficient design strategy for thermal comfort in hot and humid climates. The building forms can generate different pressures and temperatures to induce natural ventilation. This thesis develops a ...

  5. Innovative Energy Efficient Industrial Ventilation 

    E-print Network

    Litomisky, A.

    2005-01-01

    This paper was written to describe an innovative “on-demand” industrial ventilation system for woodworking, metalworking, food processing, pharmaceutical, chemical, and other industries. Having analyzed existing industrial ventilation in 130...

  6. Central Fan Integrated Ventilation Systems

    SciTech Connect

    2009-05-12

    This information sheet describes one example of a ventilation system design, a central fan integrated supply (CFIS) system, a mechanical ventilation and pollutant source control to ensure that there is reasonable indoor air quality inside the house.

  7. Ventilation flow: Submerged

    NASA Technical Reports Server (NTRS)

    Hutchinson, D.

    1985-01-01

    The ventilation system on a submarine is discussed. When the submarine is submerged. The ventilation system provides a conditioned atmosphere in the ship with complete isolation from the outside. A conditioned atmosphere includes not only filtration and temperature and humidity control, but also air purification (removal of potentially harmful quantities of impurities and comtaminants) and revitalization (addition of vital life support oxygen). Carbon dioxide removal, the oxygen system, air conditioning, carbon monoxide removal, hydrogen removal, and atmosphere monitoring systems are among the topics discussed.

  8. Noninvasive ventilation in withdrawal from mechanical ventilation.

    PubMed

    Ferrer, Miquel; Sellares, Jacobo; Torres, Antoni

    2014-08-01

    Patients with chronic airflow obstruction and difficult or prolonged weaning are at increased risk for prolonged invasive mechanical ventilation (IMV). Several randomized controlled trials mainly conducted in patients who had pre-existing lung disease have shown that the use of noninvasive ventilation (NIV) to advance extubation in patients with difficult and prolonged weaning can result in reduced periods of endotracheal intubation, complication rates, and improved survival. Patients in these studies were hemodynamically stable, with a normal level of consciousness, no fever, and a preserved cough reflex. The use of NIV in the management of mixed populations with respiratory failure after extubation, including small proportions of chronic respiratory patients did not show clinical benefits included. By contrast, NIV immediately after extubation is effective in avoiding respiratory failure after extubation and improving survival in patients at risk for this complication, particularly those with chronic respiratory disorders, cardiac comorbidity, and hypercapnic respiratory failure. Finally, both continuous positive airway pressure and NIV can improve clinical outcomes in patients with postoperative acute respiratory failure, particularly abdominal and thoracic surgery. PMID:25111647

  9. [Optimising speech during artificial ventilation].

    PubMed

    Gonzalez-Bermejo, J; Prigent, H

    2005-09-01

    Speech is an essential component of quality of life for patients treated with long term mechanical ventilation. Therefore trying to improve phonation should always sought by physicians treating these patients. We review the different tools and techniques available in order to restore speech for patients with home mechanical ventilation whether ventilation is done continuously or not. PMID:16294188

  10. RESIDENTIAL VENTILATION AND ENERGY CHARACTERISTICS*

    E-print Network

    RESIDENTIAL VENTILATION AND ENERGY CHARACTERISTICS* Max Sherman Nance Matson Energy Performance Berkeley, California The role of ventilation in the housing stock is to provide fresh air and to dilute to provide this ventilation service, either directly for moving the air or indirectly for conditioning

  11. How to Plan Ventilation Systems.

    ERIC Educational Resources Information Center

    Clarke, John H.

    1963-01-01

    Ventilation systems for factory safety demand careful planning. The increased heat loads and new processes of industry have introduced complex ventilation problems in--(1) ventilation supply, (2) duct work design, (3) space requirements, (4) hood face velocities, (5) discharge stacks, and (6) building eddies. This article describes and diagrams…

  12. RESIDENTIAL VENTILATION STUDY

    EPA Science Inventory

    This project evaluated the effectiveness, first costs and operational costs of various types of residential ventilation systems in three different climates in the U.S. The Agency, through its Energy Star Program, recommends that builders construct homes that are energy efficient ...

  13. Measure Guideline: Ventilation Cooling

    SciTech Connect

    Springer, D.; Dakin, B.; German, A.

    2012-04-01

    The purpose of this measure guideline on ventilation cooling is to provide information on a cost-effective solution for reducing cooling system energy and demand in homes located in hot-dry and cold-dry climates. This guideline provides a prescriptive approach that outlines qualification criteria, selection considerations, and design and installation procedures.

  14. Space station ventilation study

    NASA Technical Reports Server (NTRS)

    Colombo, G. V.; Allen, G. E.

    1972-01-01

    A ventilation system design and selection method which is applicable to any manned vehicle were developed. The method was used to generate design options for the NASA 33-foot diameter space station, all of which meet the ventilation system design requirements. System characteristics such as weight, volume, and power were normalized to dollar costs for each option. Total system costs for the various options ranged from a worst case $8 million to a group of four which were all approximately $2 million. A system design was then chosen from the $2 million group and is presented in detail. A ventilation system layout was designed for the MSFC space station mockup which provided comfortable, efficient ventilation of the mockup. A conditioned air distribution system design for the 14-foot diameter modular space station, using the same techniques, is also presented. The tradeoff study resulted in the selection of a system which costs $1.9 million, as compared to the alternate configuration which would have cost $2.6 million.

  15. SEVENTH INTERIM STATUS REPORT: MODEL 9975 PCV O-RING FIXTURE LONG-TERM LEAK PERFORMANCE

    SciTech Connect

    Daugherty, W.

    2012-08-30

    A series of experiments to monitor the aging performance of Viton® GLT O-rings used in the Model 9975 package has been ongoing since 2004 at the Savannah River National Laboratory. Seventy tests using mock-ups of 9975 Primary Containment Vessels (PCVs) were assembled and heated to temperatures ranging from 200 to 450 ºF. They were leak-tested initially and have been tested periodically to determine if they meet the criterion of leak-tightness defined in ANSI standard N14.5-97. Fourteen additional tests were initiated in 2008 with GLT-S O-rings heated to temperatures ranging from 200 to 400 ºF. High temperature aging continues for 23 GLT O-ring fixtures at 200 – 270 ºF. Room temperature leak test failures have been experienced in all of the GLT O-ring fixtures aging at 350 ºF and higher temperatures, and in 8 fixtures aging at 300 ºF. The remaining GLT O-ring fixtures aging at 300 ºF have been retired from testing following more than 5 years at temperature without failure. No failures have yet been observed in GLT O-ring fixtures aging at 200 ºF for 54-72 months, which is still bounding to O-ring temperatures during storage in K-Area Complex (KAC). Based on expectations that the fixtures aging at 200 ºF will remain leak-tight for a significant period yet to come, 2 additional fixtures began aging in 2011 at an intermediate temperature of 270 ºF, with hopes that they may reach a failure condition before the 200 ºF fixtures. High temperature aging continues for 6 GLT-S O-ring fixtures at 200 – 300 ºF. Room temperature leak test failures have been experienced in all 8 of the GLT-S O-ring fixtures aging at 350 and 400 ºF. No failures have yet been observed in GLT-S O-ring fixtures aging at 200 - 300 ºF for 30 - 36 months. For O-ring fixtures that have failed the room temperature leak test and been disassembled, the O-rings displayed a compression set ranging from 51 – 96%. This is greater than seen to date for any packages inspected during KAC field surveillance (24% average). For GLT O-rings, separate service life estimates have been made based on the O-ring fixture leak test data and based on compression stress relaxation (CSR) data. These two predictive models show reasonable agreement at higher temperatures (350 – 400 ºF). However, at 300 ºF, the room temperature leak test failures to date experienced longer aging times than predicted by the CSRbased model. This suggests that extrapolations of the CSR model predictions to temperatures below 300 ºF will provide a conservative prediction of service life relative to the leak rate criterion. Leak test failure data at lower temperatures are needed to verify this apparent trend. Insufficient failure data exist currently to perform a similar comparison for GLT-S O-rings. Aging and periodic leak testing will continue for the remaining PCV O-ring fixtures.

  16. Interleukin-1? Level Is Increased in Vitreous of Patients with Neovascular Age-Related Macular Degeneration (nAMD) and Polypoidal Choroidal Vasculopathy (PCV)

    PubMed Central

    Xie, Wankun; Shi, Xuan; Li, Fangting; Yang, Fei; Sun, Yaoyao; Huang, Lvzhen; Li, Xiaoxin

    2015-01-01

    Purpose To examine the expression of pro-interleukin-1? (pro-IL-1?) and interleukin-1? (IL-1?) in the vitreous body of patients with neovascular age-related macular degeneration(nAMD), polypoidal choroidal vasculopathy (PCV), proliferative diabetic retinopathy (PDR), retinal vein occlusion (RVO) or Eales’ disease to further elucidate the role of IL-1? and inflammation in the pathogenesis of neovascular retinal disease. Design Prospective clinical laboratory investigation study. Methods All patients enrolled had vitreous hemorrhage due to nAMD, PCV, PDR, RVO or Eales’ disease that required vitrectomy. Patients were excluded for any history of active intraocular inflammation, or other ophthalmic surgery besides vitrectomy. Control samples were obtained from patients with idiopathic macular epiretinal membrane. A total of fifty vitreous samples were collected from patient during vitrectomy. Pro-IL-1? and IL-1? expression were measured by enzyme-linked immunosorbent assay (ELISA). Results were analyzed statistically using nonparametric tests. Results Expression of pro-IL-1? protein was increased by 2.83-fold and 9.19-fold in PCV and nAMD vitreous samples relative to control, respectively. Expression of IL-? protein was increased by 10-fold and 4.83-fold in PCV and nAMD vitreous samples relative to control, respectively. Conclusions Our results demonstrate that expression of pro-IL-1? and IL-1? proteins is higher in PCV and nAMD. The roles of pro-IL-1? and IL-1? as inflammatory mediators in the development of PCV and nAMD may be associated with photoreceptor degeneration and neovascularization which necessitates further study. PMID:25978536

  17. ASHRAE and residential ventilation

    SciTech Connect

    Sherman, Max H.

    2003-10-01

    In the last quarter of a century, the western world has become increasingly aware of environmental threats to health and safety. During this period, people psychologically retreated away from outdoors hazards such as pesticides, smog, lead, oil spills, and dioxin to the seeming security of their homes. However, the indoor environment may not be healthier than the outdoor environment, as has become more apparent over the past few years with issues such as mold, formaldehyde, and sick-building syndrome. While the built human environment has changed substantially over the past 10,000 years, human biology has not; poor indoor air quality creates health risks and can be uncomfortable. The human race has found, over time, that it is essential to manage the indoor environments of their homes. ASHRAE has long been in the business of ventilation, but most of the focus of that effort has been in the area of commercial and institutional buildings. Residential ventilation was traditionally not a major concern because it was felt that, between operable windows and envelope leakage, people were getting enough outside air in their homes. In the quarter of a century since the first oil shock, houses have gotten much more energy efficient. At the same time, the kinds of materials and functions in houses changed in character in response to people's needs. People became more environmentally conscious and aware not only about the resources they were consuming but about the environment in which they lived. All of these factors contributed to an increasing level of public concern about residential indoor air quality and ventilation. Where once there was an easy feeling about the residential indoor environment, there is now a desire to define levels of acceptability and performance. Many institutions--both public and private--have interests in Indoor Air Quality (IAQ), but ASHRAE, as the professional society that has had ventilation as part of its mission for over 100 years, is the logical place to provide leadership. This leadership has been demonstrated most recently by the publication of the first nationally recognized standard on ventilation in homes, ASHRAE Standard 62.2-2003, which builds on work that has been part of ASHRAE for many years and will presumably continue. Homeowners and occupants, which includes virtually all of us, will benefit from the application of Standard 62.2 and use of the top ten list. This activity is exactly the kind of benefit to society that the founders of ASHRAE envisioned and is consistent with ASHRAE's mission and vision. ASHRAE members should be proud of their Society for taking leadership in residential ventilation.

  18. Harnessing natural ventilation benefits.

    PubMed

    O'Leary, John

    2013-04-01

    Making sure that a healthcare establishment has a good supply of clean fresh air is an important factor in keeping patients, staff, and visitors, free from the negative effects of CO2 and other contaminants. John O'Leary of Trend Controls, a major international supplier of building energy management solutions (BEMS), examines the growing use of natural ventilation, and the health, energy-saving, and financial benefits, that it offers. PMID:23678661

  19. Improved Performance With Ventilation

    NASA Astrophysics Data System (ADS)

    Kawakami, Ellison; Lee, Seung Jae; Karn, Ashish; Hong, Jiarong; Arndt, Roger

    2013-11-01

    Drag reduction and/or speed augmentation of marine vehicles by means of supercavitation is a topic of great interest. During the initial launch of a supercavitating vehicle, ventilation is required to supply an artificial cavity until conditions at which a natural supercavity can be sustained are reached. Various aspects of the flow physics of a supercavitating vehicle have been under investigation for several years at Saint Anthony Falls Laboratory. Both steady flow and simulated flow below a wave train have been studied. Using a high speed camera and the proper software, it is possible to synchronize cavity dimensions with pressure measurements taken inside the cavity to permit an in-depth study of unsteadiness. It was found that flow unsteadiness caused a decrease in the overall length of the supercavity while having only a minimal effect on the maximum diameter. Results regarding supercavity shape, ventilation demand, cavitation parameters and closure methods are reviewed in light of new studies that focused on various closure mechanisms. Drag reduction and/or speed augmentation of marine vehicles by means of supercavitation is a topic of great interest. During the initial launch of a supercavitating vehicle, ventilation is required to supply an artificial cavity until conditions at which a natural supercavity can be sustained are reached. Various aspects of the flow physics of a supercavitating vehicle have been under investigation for several years at Saint Anthony Falls Laboratory. Both steady flow and simulated flow below a wave train have been studied. Using a high speed camera and the proper software, it is possible to synchronize cavity dimensions with pressure measurements taken inside the cavity to permit an in-depth study of unsteadiness. It was found that flow unsteadiness caused a decrease in the overall length of the supercavity while having only a minimal effect on the maximum diameter. Results regarding supercavity shape, ventilation demand, cavitation parameters and closure methods are reviewed in light of new studies that focused on various closure mechanisms. Sponsored by ONR.

  20. Ventilation Air Preconditioning Systems 

    E-print Network

    Khattar, M.; Brandemuehl, M. J.

    1996-01-01

    , maintaining excellent control of temperature and humidity within each zone. Filter racks are 4" deep to accommodate a wide range of highefficiency filters. Tempering Outside Air in Winter In winter, the recirculation air can be heated rather than cooled...-cooled refrigeration racks. Simulation of the WalMart superstore application of these units showed a potential cost savings of 22.6% over conventional WAC&R systems. Zero-ODP Refrigerant The ventilation chiller uses R-407C, an environmentally acceptable...

  1. Pretest Predictions for Ventilation Tests

    SciTech Connect

    Y. Sun; H. Yang; H.N. Kalia

    2007-01-17

    The objective of this calculation is to predict the temperatures of the ventilating air, waste package surface, concrete pipe walls, and insulation that will be developed during the ventilation tests involving various test conditions. The results will be used as input to the following three areas: (1) Decisions regarding testing set-up and performance. (2) Assessing how best to scale the test phenomena measured. (3) Validating numerical approach for modeling continuous ventilation. The scope of the calculation is to identify the physical mechanisms and parameters related to thermal response in the ventilation tests, and develop and describe numerical methods that can be used to calculate the effects of continuous ventilation. Sensitivity studies to assess the impact of variation of linear power densities (linear heat loads) and ventilation air flow rates are included. The calculation is limited to thermal effect only.

  2. Mechanical Ventilation and Bronchopulmonary Dysplasia.

    PubMed

    Keszler, Martin; Sant'Anna, Guilherme

    2015-12-01

    Mechanical ventilation is an important potentially modifiable risk factor for the development of bronchopulmonary dysplasia. Effective use of noninvasive respiratory support reduces the risk of lung injury. Lung volume recruitment and avoidance of excessive tidal volume are key elements of lung-protective ventilation strategies. Avoidance of oxidative stress, less invasive methods of surfactant administration, and high-frequency ventilation are also important factors in lung injury prevention. PMID:26593078

  3. Max-pressure Controller for Stabilizing the Queues in6 Signalized Arterial Networks7

    E-print Network

    1 2 3 4 5 Max-pressure Controller for Stabilizing the Queues in6 Signalized Arterial Networks7 8 9.A. Fayazi, P. Varaiya 2 ABSTRACT1 The problem of arterial signal control is considered here. Urban of arterial traffic systems,5 is tested in simulations. Different modifications of the controller are analyzed

  4. Pressure-controlled motion of single polymers through solid-state nanopores

    E-print Network

    Golovchenko, Jene A.

    1 Pressure-controlled motion of single polymers through solid-state nanopores Bo Lu1 , David P of a pressure gradient across the nanopore yields a second molecular driving force that provides new freedom for studying molecules in nanopores. In this work, we show that opposing pressure and voltage bias enables

  5. Phylogenetic comparison of porcine circovirus type 2 (PCV2) and porcine reproductive respiratory syndrome virus (PRRSV) strains detected in domestic pigs until 2008 and in 2012 in Croatia

    PubMed Central

    2014-01-01

    Background Porcine circovirus type 2 (PCV2) and porcine reproductive and respiratory syndrome virus (PRRSV) have been present for the last 2 decades in Croatia, causing large economical losses in the pig production. The clinical features of the infections are mostly manifested by the development of respiratory problems, weight loss and poor growth performance, as well as reproductive failure in pregnant sows. Even though the infections are continuously recognized in some regions in Croatia, the heterogeneity of the detected viral strains from 2012 has not yet been investigated. The objective of this study was to compare virus strains of PCV2 and PRRSV detected until 2008 in Croatia with strains isolated in 2012 to gain a better epidemiological understanding of these two infections. Results PCV2 and PRRSV strains detected in 2012 in fattening pigs from regions where these two diseases have been previously described were compared to strains that have been detected in the same regions within the past two decades. The phylogenetic analysis revealed that the circulating PCV2 and PRRSV strains are distantly related to the previously described Croatian viral strains. However, when compared to known isolates from the GenBank a high genetic identity of PRRSV isolates with isolates from Hungary, Denmark and the Netherlands was found. Conclusion The results of this study reveal that even though PCV2 and PRRSV are constantly present in the investigated regions in Croatia, the viral strains found in 2012 genetically differ from those detected in earlier years. This indicates that new entries into the pig population appeared with regard to both infections, probably as a result of pig trade. PMID:24839544

  6. Influence of husbandry and control measures on porcine circovirus type 2 (PCV-2) dynamics within a farrow-to-finish pig farm: a modelling approach.

    PubMed

    Andraud, M; Rose, N; Grasland, B; Pierre, J S; Jestin, A; Madec, F

    2009-11-01

    We assessed, using a modelling approach, the influence of several management practices within a farrow-to-finish farm on the age of PCV-2 infection. The impact of PCV-2 vaccination with different vaccination schemes on infection dynamics, was also tested. A stochastic individual-based model describing the population dynamics in a typical French farrow-to-finish pig farm was built and coupled with an epidemiological model of PCV-2 infection. The parameters of the infectious model were mainly obtained from previous transmission experiments. Results were subjected to a survival analysis of time-to-infection. For each comparison, the reference situation was no vaccination followed by random mixing of piglets after birth and after weaning. The risk of early infection was significantly reduced when mixing of piglets was reduced at different stages (avoiding cross-fostering and grouping piglets by litters in small pens after weaning, hazard ratio (HR)=0.52 [0.46; 0.59]). Sow-targeted vaccination delayed the infectious process until the waning of passive immunity and piglet-targeted vaccination considerably decreased the force of infection leading to a dramatic decrease of the total number of infections (HR=0.44 [0.37; 0.54]). The effect was even more pronounced when strict management measures were applied (HR=0.24 [0.19; 0.31]). Changing from a low (3%) prevalence of PCV-2-infected semen to a higher one (18%) significantly increased the risk of early infections (HR=1.36 [1.2; 1.53]), whereas reducing replacement rate or changing sow housing from individual crates to group housing had a limited impact on PCV-2 dynamics. PMID:19720410

  7. 14 CFR 252.9 - Ventilation systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Ventilation systems. 252.9 Section 252...SMOKING ABOARD AIRCRAFT § 252.9 Ventilation systems. Air carriers shall prohibit smoking whenever the ventilation system is not fully...

  8. 24 CFR 3285.505 - Crawlspace ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 false Crawlspace ventilation. 3285.505 Section 3285.505...Features § 3285.505 Crawlspace ventilation. (a) A crawlspace with skirting must be provided with ventilation openings. The minimum net area...

  9. 46 CFR 194.10-25 - Ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Ventilation. 194.10-25 Section 194.10-25...MATERIALS Magazines § 194.10-25 Ventilation. (a) Integral magazines. ...be provided with natural or mechanical ventilation. Design calculations shall be...

  10. 46 CFR 194.20-5 - Ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Ventilation. 194.20-5 Section 194...or Storerooms § 194.20-5 Ventilation. (a) Chemical storerooms shall be equipped with a power ventilation system of exhaust type. The...

  11. 30 CFR 57.8520 - Ventilation plan.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Ventilation plan. 57.8520 Section 57.8520...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Ventilation Underground Only § 57.8520 Ventilation plan. A plan of the mine...

  12. 30 CFR 57.8520 - Ventilation plan.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Ventilation plan. 57.8520 Section 57.8520...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Ventilation Underground Only § 57.8520 Ventilation plan. A plan of the mine...

  13. 46 CFR 194.10-25 - Ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Ventilation. 194.10-25 Section 194.10-25...MATERIALS Magazines § 194.10-25 Ventilation. (a) Integral magazines. ...be provided with natural or mechanical ventilation. Design calculations shall be...

  14. 46 CFR 194.20-5 - Ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Ventilation. 194.20-5 Section 194...or Storerooms § 194.20-5 Ventilation. (a) Chemical storerooms shall be equipped with a power ventilation system of exhaust type. The...

  15. 30 CFR 57.8520 - Ventilation plan.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Ventilation plan. 57.8520 Section 57.8520...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Ventilation Underground Only § 57.8520 Ventilation plan. A plan of the mine...

  16. 14 CFR 252.9 - Ventilation systems.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Ventilation systems. 252.9 Section 252...SMOKING ABOARD AIRCRAFT § 252.9 Ventilation systems. Air carriers shall prohibit smoking whenever the ventilation system is not fully...

  17. 14 CFR 252.9 - Ventilation systems.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Ventilation systems. 252.9 Section 252...SMOKING ABOARD AIRCRAFT § 252.9 Ventilation systems. Air carriers shall prohibit smoking whenever the ventilation system is not fully...

  18. 46 CFR 194.10-25 - Ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false Ventilation. 194.10-25 Section 194.10-25...MATERIALS Magazines § 194.10-25 Ventilation. (a) Integral magazines. ...be provided with natural or mechanical ventilation. Design calculations shall be...

  19. 30 CFR 57.8520 - Ventilation plan.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Ventilation plan. 57.8520 Section 57.8520...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Ventilation Underground Only § 57.8520 Ventilation plan. A plan of the mine...

  20. 24 CFR 3285.505 - Crawlspace ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 false Crawlspace ventilation. 3285.505 Section 3285.505...Features § 3285.505 Crawlspace ventilation. (a) A crawlspace with skirting must be provided with ventilation openings. The minimum net area...

  1. 46 CFR 194.20-5 - Ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Ventilation. 194.20-5 Section 194...or Storerooms § 194.20-5 Ventilation. (a) Chemical storerooms shall be equipped with a power ventilation system of exhaust type. The...

  2. 24 CFR 3285.505 - Crawlspace ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 false Crawlspace ventilation. 3285.505 Section 3285.505...Features § 3285.505 Crawlspace ventilation. (a) A crawlspace with skirting must be provided with ventilation openings. The minimum net area...

  3. 14 CFR 252.9 - Ventilation systems.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Ventilation systems. 252.9 Section 252...SMOKING ABOARD AIRCRAFT § 252.9 Ventilation systems. Air carriers shall prohibit smoking whenever the ventilation system is not fully...

  4. 24 CFR 3285.505 - Crawlspace ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 false Crawlspace ventilation. 3285.505 Section 3285.505...Features § 3285.505 Crawlspace ventilation. (a) A crawlspace with skirting must be provided with ventilation openings. The minimum net area...

  5. 46 CFR 194.10-25 - Ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Ventilation. 194.10-25 Section 194.10-25...MATERIALS Magazines § 194.10-25 Ventilation. (a) Integral magazines. ...be provided with natural or mechanical ventilation. Design calculations shall be...

  6. 30 CFR 57.8520 - Ventilation plan.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Ventilation plan. 57.8520 Section 57.8520...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Ventilation Underground Only § 57.8520 Ventilation plan. A plan of the mine...

  7. 46 CFR 194.20-5 - Ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Ventilation. 194.20-5 Section 194...or Storerooms § 194.20-5 Ventilation. (a) Chemical storerooms shall be equipped with a power ventilation system of exhaust type. The...

  8. 46 CFR 194.20-5 - Ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false Ventilation. 194.20-5 Section 194...or Storerooms § 194.20-5 Ventilation. (a) Chemical storerooms shall be equipped with a power ventilation system of exhaust type. The...

  9. 46 CFR 194.10-25 - Ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Ventilation. 194.10-25 Section 194.10-25...MATERIALS Magazines § 194.10-25 Ventilation. (a) Integral magazines. ...be provided with natural or mechanical ventilation. Design calculations shall be...

  10. 14 CFR 252.9 - Ventilation systems.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Ventilation systems. 252.9 Section 252...SMOKING ABOARD AIRCRAFT § 252.9 Ventilation systems. Air carriers shall prohibit smoking whenever the ventilation system is not fully...

  11. Laboratory and Industrial Ventilation

    NASA Technical Reports Server (NTRS)

    1972-01-01

    This handbook supplements the Facilities Engineering Handbook (NHB 7320.1) and provides additional policies and criteria for uniform application to ventilation systems. It expands basic requirements, provides additional design and construction guidance, and places emphasis on those design considerations which will provide for greater effectiveness in the use of these systems. The provisions of this handbook are applicable to all NASA field installations and the Jet Propulsion Laboratory. Since supply of this handbook is limited, abstracts of the portion or portions applicable to a given requirement will be made for the individual specific needs encountered rather than supplying copies of the handbook as has been past practice.

  12. Improving Urban African Americans’ Blood Pressure Control through Multi-level Interventions in the Achieving Blood Pressure Control Together (ACT) Study: A Randomized Clinical Trial

    PubMed Central

    Ephraim, Patti L.; Hill-Briggs, Felicia; Roter, Debra; Bone, Lee; Wolff, Jennifer; Lewis-Boyer, LaPricia; Levine, David; Aboumatar, Hanan; Cooper, Lisa A; Fitzpatrick, Stephanie; Gudzune, Kimberly; Albert, Michael; Monroe, Dwyan; Simmons, Michelle; Hickman, Debra; Purnell, Leon; Fisher, Annette; Matens, Richard; Noronha, Gary; Fagan, Peter; Ramamurthi, Hema; Ameling, Jessica; Charlston, Jeanne; Sam, Tanyka; Carson, Kathryn A.; Wang, Nae-Yuh; Crews, Deidra; Greer, Raquel; Sneed, Valerie; Flynn, Sarah J.; DePasquale, Nicole; Boulware, L. Ebony

    2014-01-01

    Background Given their high rates of uncontrolled blood pressure, urban African Americans comprise a particularly vulnerable subgroup of persons with hypertension. Substantial evidence has demonstrated the important role of family and community support in improving patients’ management of a variety of chronic illnesses. However, studies of multilevel interventions designed specifically to improve urban African American patients’ blood pressure self-management by simultaneously leveraging patient, family, and community strengths are lacking. Methods/Design We report the protocol of the Achieving Blood Pressure Control Together (ACT) study, a randomized controlled trial designed to study the effectiveness of interventions that engage patient, family, and community-level resources to facilitate urban African American hypertensive patients’ improved hypertension self-management and subsequent hypertension control. African American patients with uncontrolled hypertension receiving health care in an urban primary care clinic will be randomly assigned to receive 1) an educational intervention led by a community health worker alone, 2) the community health worker intervention plus a patient and family communication activation intervention, or 3) the community health worker intervention plus a problem-solving intervention. All participants enrolled in the study will receive and be trained to use a digital home blood pressure machine. The primary outcome of the randomized controlled trial will be patients’ blood pressure control at 12 months. Discussion Results from the ACT study will provide needed evidence on the effectiveness of comprehensive multi-level interventions to improve urban African American patients’ hypertension control. PMID:24956323

  13. 46 CFR 194.10-25 - Ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... CONTROL OF EXPLOSIVES AND OTHER HAZARDOUS MATERIALS Magazines § 194.10-25 Ventilation. (a) Integral magazines. (1) All integral magazines shall be provided with natural or mechanical ventilation....

  14. Transpired Air Collectors - Ventilation Preheating

    SciTech Connect

    Christensen, C.

    2006-06-22

    Many commercial and industrial buildings have high ventilation rates. Although all that fresh air is great for indoor air quality, heating it can be very expensive. This short (2-page) fact sheet describes a technology available to use solar energy to preheat ventilation air and dramatically reduce utility bills.

  15. Ventilation of an hydrofoil wake

    NASA Astrophysics Data System (ADS)

    Arndt, Roger; Lee, Seung Jae; Monson, Garrett

    2013-11-01

    Ventilation physics plays a role in a variety of important engineering applications. For example, hydroturbine ventilation is used for control of vibration and cavitation erosion and more recently for improving the dissolved oxygen content of the flow through the turbine. The latter technology has been the focus of an ongoing study involving the ventilation of an hydrofoil wake to determine the velocity and size distribution of bubbles in a bubbly wake. This was carried out by utilizing particle shadow velocimetry (PSV). This technique is a non-scattering approach that relies on direct in-line volume illumination by a pulsed source such as a light-emitting diode (LED). The data are compared with previous studies of ventilated flow. The theoretical results of Hinze suggest that a scaling relationship is possible that can lead to developing appropriate design parameters for a ventilation system. Sponsored by ONR and DOE.

  16. Inhalation therapy in mechanical ventilation

    PubMed Central

    Maccari, Juçara Gasparetto; Teixeira, Cassiano; Gazzana, Marcelo Basso; Savi, Augusto; Dexheimer-Neto, Felippe Leopoldo; Knorst, Marli Maria

    2015-01-01

    Patients with obstructive lung disease often require ventilatory support via invasive or noninvasive mechanical ventilation, depending on the severity of the exacerbation. The use of inhaled bronchodilators can significantly reduce airway resistance, contributing to the improvement of respiratory mechanics and patient-ventilator synchrony. Although various studies have been published on this topic, little is known about the effectiveness of the bronchodilators routinely prescribed for patients on mechanical ventilation or about the deposition of those drugs throughout the lungs. The inhaled bronchodilators most commonly used in ICUs are beta adrenergic agonists and anticholinergics. Various factors might influence the effect of bronchodilators, including ventilation mode, position of the spacer in the circuit, tube size, formulation, drug dose, severity of the disease, and patient-ventilator synchrony. Knowledge of the pharmacological properties of bronchodilators and the appropriate techniques for their administration is fundamental to optimizing the treatment of these patients. PMID:26578139

  17. Acculturation, Medication Adherence, Lifestyle Behaviors, and Blood Pressure Control Among Arab Americans

    PubMed Central

    Tailakh, Ayman K.; Evangelista, Lorraine S.; Morisky, Donald E.; Mentes, Janet C.; Pike, Nancy A.; Phillips, Linda R.

    2015-01-01

    Purpose The aim of this study was to examine the relationship between acculturation, medication adherence, lifestyle behaviors (e.g., physical activity, nutrition, weight control), and blood pressure control among hypertensive Arab Americans. Design The study utilized a cross-sectional descriptive design. A convenience sample of 126 participants completed questionnaires and had measures of blood pressure, weight, and height. Forty-six participants were hypertensive and were included in the analysis. Results Only 29.2% of participants reported high medication adherence. High medication adherence was associated with lower diastolic blood pressure, eating a healthy diet, and following lifestyle modifications. Acculturation was significantly associated with physical activity and body mass index. Conclusion Our study found that acculturated participants were more adherent to medications and physical activity and had better blood pressure control. Further studies are needed to explore how acculturation improves adherence and what factors contribute to better adherence in order to design culturally sensitive interventions. PMID:24848347

  18. Cardiac gated ventilation

    SciTech Connect

    Hanson, C.W. III; Hoffman, E.A.

    1995-12-31

    There are several theoretic advantages to synchronizing positive pressure breaths with the cardiac cycle, including the potential for improving distribution of pulmonary and myocardial blood flow and enhancing cardiac output. The authors evaluated the effects of synchronizing respiration to the cardiac cycle using a programmable ventilator and electron beam CT (EBCT) scanning. The hearts of anesthetized dogs were imaged during cardiac gated respiration with a 50 msec scan aperture. Multi slice, short axis, dynamic image data sets spanning the apex to base of the left ventricle were evaluated to determine the volume of the left ventricular chamber at end-diastole and end-systole during apnea, systolic and diastolic cardiac gating. The authors observed an increase in cardiac output of up to 30% with inspiration gated to the systolic phase of the cardiac cycle in a non-failing model of the heart.

  19. Cardiac gated ventilation

    NASA Astrophysics Data System (ADS)

    Hanson, C. William, III; Hoffman, Eric A.

    1995-05-01

    There are several theoretic advantages to synchronizing positive pressure breaths with the cardiac cycle, including the potential for improving distribution of pulmonary and myocardial blood flow and enhancing cardiac output. We evaluated the effects of synchronizing respiration to the cardiac cycle using a programmable ventilator and electron beam CT (EBCT) scanning. The hearts of anesthetized dogs were imaged during cardiac gated respiration with a 50msec scan aperture. Multislice, short axis, dynamic image data sets spanning the apex to base of the left ventricle were evaluated to determine the volume of the left ventricular chamber at end-diastole and end-systole during apnea, systolic and diastolic cardiac gating. We observed an increase in cardiac output of up to 30% with inspiration gated to the systolic phase of the cardiac cycle in a nonfailing model of the heart.

  20. Solar ventilation and tempering

    NASA Astrophysics Data System (ADS)

    Adámek, Karel; Pavlů, Miloš; Bandouch, Milan

    2014-08-01

    The paper presents basic information about solar panels, designed, realized and used for solar ventilation of rooms. Used method of numerical flow simulation gives good overview about warming and flowing of the air in several kinds of realized panels (window, facade, chimney). Yearlong measurements give a good base for calculations of economic return of invested capital. The operation of the system in transient period (spring, autumn) prolongs the period without classical heating of the room or building, in winter the classical heating is supported. In the summer period the system, furnished with chimney, can exhaust inner warm air together with necessary cooling of the system by gravity circulation, only. System needs not any invoiced energy source; it is supplied entirely by solar energy. Large building systems are supported by classical electric fan respectively.

  1. Estimation of Lung Ventilation

    NASA Astrophysics Data System (ADS)

    Ding, Kai; Cao, Kunlin; Du, Kaifang; Amelon, Ryan; Christensen, Gary E.; Raghavan, Madhavan; Reinhardt, Joseph M.

    Since the primary function of the lung is gas exchange, ventilation can be interpreted as an index of lung function in addition to perfusion. Injury and disease processes can alter lung function on a global and/or a local level. MDCT can be used to acquire multiple static breath-hold CT images of the lung taken at different lung volumes, or with proper respiratory control, 4DCT images of the lung reconstructed at different respiratory phases. Image registration can be applied to this data to estimate a deformation field that transforms the lung from one volume configuration to the other. This deformation field can be analyzed to estimate local lung tissue expansion, calculate voxel-by-voxel intensity change, and make biomechanical measurements. The physiologic significance of the registration-based measures of respiratory function can be established by comparing to more conventional measurements, such as nuclear medicine or contrast wash-in/wash-out studies with CT or MR. An important emerging application of these methods is the detection of pulmonary function change in subjects undergoing radiation therapy (RT) for lung cancer. During RT, treatment is commonly limited to sub-therapeutic doses due to unintended toxicity to normal lung tissue. Measurement of pulmonary function may be useful as a planning tool during RT planning, may be useful for tracking the progression of toxicity to nearby normal tissue during RT, and can be used to evaluate the effectiveness of a treatment post-therapy. This chapter reviews the basic measures to estimate regional ventilation from image registration of CT images, the comparison of them to the existing golden standard and the application in radiation therapy.

  2. Subsurface Ventilation System Description Document

    SciTech Connect

    2000-10-12

    The Subsurface Ventilation System supports the construction and operation of the subsurface repository by providing air for personnel and equipment and temperature control for the underground areas. Although the system is located underground, some equipment and features may be housed or located above ground. The system ventilates the underground by providing ambient air from the surface throughout the subsurface development and emplacement areas. The system provides fresh air for a safe work environment and supports potential retrieval operations by ventilating and cooling emplacement drifts. The system maintains compliance within the limits established for approved air quality standards. The system maintains separate ventilation between the development and waste emplacement areas. The system shall remove a portion of the heat generated by the waste packages during preclosure to support thermal goals. The system provides temperature control by reducing drift temperature to support potential retrieval operations. The ventilation system has the capability to ventilate selected drifts during emplacement and retrieval operations. The Subsurface Facility System is the main interface with the Subsurface Ventilation System. The location of the ducting, seals, filters, fans, emplacement doors, regulators, and electronic controls are within the envelope created by the Ground Control System in the Subsurface Facility System. The Subsurface Ventilation System also interfaces with the Subsurface Electrical System for power, the Monitored Geologic Repository Operations Monitoring and Control System to ensure proper and safe operation, the Safeguards and Security System for access to the emplacement drifts, the Subsurface Fire Protection System for fire safety, the Emplacement Drift System for repository performance, and the Backfill Emplacement and Subsurface Excavation Systems to support ventilation needs.

  3. Subsurface Ventilation System Description Document

    SciTech Connect

    Eric Loros

    2001-07-25

    The Subsurface Ventilation System supports the construction and operation of the subsurface repository by providing air for personnel and equipment and temperature control for the underground areas. Although the system is located underground, some equipment and features may be housed or located above ground. The system ventilates the underground by providing ambient air from the surface throughout the subsurface development and emplacement areas. The system provides fresh air for a safe work environment and supports potential retrieval operations by ventilating and cooling emplacement drifts. The system maintains compliance within the limits established for approved air quality standards. The system maintains separate ventilation between the development and waste emplacement areas. The system shall remove a portion of the heat generated by the waste packages during preclosure to support thermal goals. The system provides temperature control by reducing drift temperature to support potential retrieval operations. The ventilation system has the capability to ventilate selected drifts during emplacement and retrieval operations. The Subsurface Facility System is the main interface with the Subsurface Ventilation System. The location of the ducting, seals, filters, fans, emplacement doors, regulators, and electronic controls are within the envelope created by the Ground Control System in the Subsurface Facility System. The Subsurface Ventilation System also interfaces with the Subsurface Electrical System for power, the Monitored Geologic Repository Operations Monitoring and Control System to ensure proper and safe operation, the Safeguards and Security System for access to the emplacement drifts, the Subsurface Fire Protection System for fire safety, the Emplacement Drift System for repository performance, and the Backfill Emplacement and Subsurface Excavation Systems to support ventilation needs.

  4. 14 CFR 23.831 - Ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Ventilation. 23.831 Section 23.831 Aeronautics...Cargo Accommodations § 23.831 Ventilation. (a) Each passenger and crew...adversely affect the ventilating air, the ventilation system must provide reasonable...

  5. 14 CFR 23.831 - Ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Ventilation. 23.831 Section 23.831 Aeronautics...Cargo Accommodations § 23.831 Ventilation. (a) Each passenger and crew...adversely affect the ventilating air, the ventilation system must provide reasonable...

  6. Co-expression of Ubiquitin gene and capsid protein gene enhances the potency of DNA immunization of PCV2 in mice

    PubMed Central

    2011-01-01

    A recombinant plasmid that co-expressed ubiquitin and porcine circovirus type 2 (PCV2) virus capsid protein (Cap), denoted as pc-Ub-Cap, and a plasmid encoding PCV2 virus Cap alone, denoted as pc-Cap, were transfected into 293T cells. Indirect immunofluorescence (IIF) and confocal microscopy were performed to measure the cellular expression of Cap. Three groups of mice were then vaccinated once every three weeks for a total of three doses with pc-Ub-Cap, pc-Cap or the empty vector pCAGGS, followed by challenging all mice intraperitoneally with 0.5 mL 106.5 TCID50/mL PCV2. To characterize the protective immune response against PCV2 infection in mice, assays of antibody titer (including different IgG isotypes), flow cytometric analysis (FCM), lymphocyte proliferation, cytokine production and viremia were evaluated. The results showed that pc-Ub-Cap and pc-Cap were efficiently expressed in 293T cells. However, pc-Ub-Cap-vaccinated animals had a significantly higher level of Cap-specific antibody and induced a stronger Th1 type cellular immune response than did pc-Cap-vaccinated animals, suggesting that ubiquitin conjugation improved both the cellular and humoral immune responses. Additionally, viral replication in blood was lower in the pc-Ub-Cap-vaccinated group than in the pc-Cap and empty vector groups, suggesting that the protective immunity induced by pc-Ub-Cap is superior to that induced by pc-Cap. PMID:21624113

  7. Use of Adaptive Support Ventilation (ASV) in Ventilator Associated Pneumonia (VAP) - A Case Report

    PubMed Central

    Kath, Bipphy; Hemanth, N; Marella, Prashanti; Rao, M H

    2009-01-01

    Summary Prolonged ventilation leads to a higher incidence of ventilator associated pneumonia(VAP) resulting in ventilator dependency, increased costs and subsequent weaning failures. Prevention and aggressive treatment of VAP along with patient friendly newer modes of ventilation like adaptive support ventilation go a long way in successful management of these cases. PMID:20640145

  8. 6. VIEW LOOKING SOUTHEAST AT VENTILATION EQUIPMENT IN SOUTH VENTILATION ...

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

    6. VIEW LOOKING SOUTHEAST AT VENTILATION EQUIPMENT IN SOUTH VENTILATION HOUSE. THIS AIR CONDITIONING SYSTEM WAS INSTALLED BY PARKS-CRAMER COMPANY OF FITCHBURG, MASSACHUSETTS WHEN THE MILL WAS CONSTRUCTED IN 1923-24. ONE AIR WASHER AND FAN ROOM EXTERIOR IS VISIBLE ON THE RIGHT. THE DUCTS FROM BOTH FAN ROOMS (CURVED METAL STRUCTURES AT CENTER AND LEFT OF PHOTO) ARE CONNECTED TO A COMMON AIR SHAFT. - Stark Mill, 117 Corinth Road, Hogansville, Troup County, GA

  9. Emerging, Non-PCV13 Serotypes 11A and 35B of Streptococcus pneumoniae Show High Potential for Biofilm Formation In Vitro

    PubMed Central

    Ardanuy, Carmen; Liñares, Josefina; Fenoll, Asunción; García, Ernesto

    2015-01-01

    Background Since the use of pneumococcal conjugate vaccines PCV7 and PCV13 in children became widespread, invasive pneumococcal disease (IPD) has dramatically decreased. Nevertheless, there has been a rise in incidence of Streptococcus pneumoniae non-vaccine serotypes (NVT) colonising the human nasopharynx. Nasopharyngeal colonisation, an essential step in the development of S. pneumoniae-induced IPD, is associated with biofilm formation. Although the capsule is the main pneumococcal virulence factor, the formation of pneumococcal biofilms might, in fact, be limited by the presence of capsular polysaccharide (CPS). Methodology/Principal Findings We used clinical isolates of 16 emerging, non-PCV13 serotypes as well as isogenic transformants of the same serotypes. The biofilm formation capacity of isogenic transformants expressing CPSs from NVT was evaluated in vitro to ascertain whether this trait can be used to predict the emergence of NVT. Fourteen out of 16 NVT analysed were not good biofilm formers, presumably because of the presence of CPS. In contrast, serotypes 11A and 35B formed ?45% of the biofilm produced by the non-encapsulated M11 strain. Conclusions/Significance This study suggest that emerging, NVT serotypes 11A and 35B deserve a close surveillance. PMID:25927917

  10. Equivalence in Ventilation and Indoor Air Quality

    SciTech Connect

    Sherman, Max; Walker, Iain; Logue, Jennifer

    2011-08-01

    We ventilate buildings to provide acceptable indoor air quality (IAQ). Ventilation standards (such as American Society of Heating, Refrigerating, and Air-Conditioning Enginners [ASHRAE] Standard 62) specify minimum ventilation rates without taking into account the impact of those rates on IAQ. Innovative ventilation management is often a desirable element of reducing energy consumption or improving IAQ or comfort. Variable ventilation is one innovative strategy. To use variable ventilation in a way that meets standards, it is necessary to have a method for determining equivalence in terms of either ventilation or indoor air quality. This study develops methods to calculate either equivalent ventilation or equivalent IAQ. We demonstrate that equivalent ventilation can be used as the basis for dynamic ventilation control, reducing peak load and infiltration of outdoor contaminants. We also show that equivalent IAQ could allow some contaminants to exceed current standards if other contaminants are more stringently controlled.

  11. Nozzle for discharging ventilation air from a ventilation system

    SciTech Connect

    Elfverson, S.E.

    1986-09-30

    This patent describes a nozzle for discharging ventilation air from a ventilation system, preferably arranged in a vehicle, including at least one outlet housing with a through-flow duct for ventilation air, a fixed plate transverse to the flow duct and rigidly attached to the outlet housing, and a plurality of plates parallel to the fixed plate. These plates are mutually displaceable in a direction transverse to the flow duct under the action of a control lever passing through the plates, the plates being formed with perforation patterns, which in coaction form ventilation ducts through which the ventilation air can flow and in response to the setting of the control lever cause deviation of the flow direction of the ventilation air. Each displaceable plate is formed with a grid cross comprising at least two intersecting bars, of which one bar has a substantially circular cross section, while the other bar has a substantially elliptical cross section and wherein the control lever is adapted to grip round a grid cross, the control lever having two pairs of longitudinal slots. One pair of the slots is adapted to grip without play one of the intersecting bars in each respective grid cross. The other pair of slots comprises a first slot adapted to grip without play the other of the intersecting bars, and a second slot formed with a width disabling engagement with the other of the intersecting bars.

  12. Decrease in Hospitalizations for Pneumonia in Children under Five Years of Age in an Indian Reservation in Panama after the Introduction of the Heptavalent Pneumococcal Conjugate Vaccine (PCV7)

    PubMed Central

    Nieto Guevara, Javier; Daza, Carlos

    2013-01-01

    This study quantifies the impact of Heptavalent-Pneumococcal Conjugate Vaccine (PCV7) in Panama on indigenous children younger than 5 years old, based on clinical pneumonia cases. This study demonstrates a significant 41.2% reduction in hospitalizations and 38.6% reduction in referrals for pneumonia following the introduction of PCV7. Burden of disease from pneumonia appears reduced in the ?12-month- and 13-to-24-month-old groups. PMID:23762081

  13. Literature Review of Displacement Ventilation 

    E-print Network

    Cho, S.; Im, P.; Haberl, J. S.

    2005-01-01

    Performance Evaluation and Design Guidelines for Displacement Ventilation” by Chen and Clicksman (2003), were used to begin the literature search. Their references include papers, articles, and web sites presenting major contributions to the understanding...

  14. Transtracheal ventilation in oral surgery.

    PubMed Central

    Layman, P. R.

    1983-01-01

    The use of transtracheal ventilation as a routine method of ventilation during anaesthesia for 60 patients with gross pathology requiring oral surgery is reported. Theoretical hazards of the technique and protection of the airway are discussed. There were no serious complications in this series. The technique is recommended as a simple and safe alternative to blind nasal intubation. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:6614769

  15. 46 CFR 111.103-1 - Power ventilation systems except machinery space ventilation systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false Power ventilation systems except machinery space ventilation systems. 111.103-1 Section 111...Stopping Systems § 111.103-1 Power ventilation systems except machinery space...

  16. 46 CFR 111.103-1 - Power ventilation systems except machinery space ventilation systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Power ventilation systems except machinery space ventilation systems. 111.103-1 Section 111...Stopping Systems § 111.103-1 Power ventilation systems except machinery space...

  17. 46 CFR 111.103-1 - Power ventilation systems except machinery space ventilation systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Power ventilation systems except machinery space ventilation systems. 111.103-1 Section 111...Stopping Systems § 111.103-1 Power ventilation systems except machinery space...

  18. 46 CFR 111.103-1 - Power ventilation systems except machinery space ventilation systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Power ventilation systems except machinery space ventilation systems. 111.103-1 Section 111...Stopping Systems § 111.103-1 Power ventilation systems except machinery space...

  19. 46 CFR 111.103-1 - Power ventilation systems except machinery space ventilation systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Power ventilation systems except machinery space ventilation systems. 111.103-1 Section 111...Stopping Systems § 111.103-1 Power ventilation systems except machinery space...

  20. Mechanical ventilation for severe asthma.

    PubMed

    Leatherman, James

    2015-06-01

    Acute exacerbations of asthma can lead to respiratory failure requiring ventilatory assistance. Noninvasive ventilation may prevent the need for endotracheal intubation in selected patients. For patients who are intubated and undergo mechanical ventilation, a strategy that prioritizes avoidance of ventilator-related complications over correction of hypercapnia was first proposed 30 years ago and has become the preferred approach. Excessive pulmonary hyperinflation is a major cause of hypotension and barotrauma. An appreciation of the key determinants of hyperinflation is essential to rational ventilator management. Standard therapy for patients with asthma undergoing mechanical ventilation consists of inhaled bronchodilators, corticosteroids, and drugs used to facilitate controlled hypoventilation. Nonconventional interventions such as heliox, general anesthesia, bronchoscopy, and extracorporeal life support have also been advocated for patients with fulminant asthma but are rarely necessary. Immediate mortality for patients who are mechanically ventilated for acute severe asthma is very low and is often associated with out-of-hospital cardiorespiratory arrest before intubation. However, patients who have been intubated for severe asthma are at increased risk for death from subsequent exacerbations and must be managed accordingly in the outpatient setting. PMID:26033128

  1. Ventilation Model and Analysis Report

    SciTech Connect

    V. Chipman

    2003-07-18

    This model and analysis report develops, validates, and implements a conceptual model for heat transfer in and around a ventilated emplacement drift. This conceptual model includes thermal radiation between the waste package and the drift wall, convection from the waste package and drift wall surfaces into the flowing air, and conduction in the surrounding host rock. These heat transfer processes are coupled and vary both temporally and spatially, so numerical and analytical methods are used to implement the mathematical equations which describe the conceptual model. These numerical and analytical methods predict the transient response of the system, at the drift scale, in terms of spatially varying temperatures and ventilation efficiencies. The ventilation efficiency describes the effectiveness of the ventilation process in removing radionuclide decay heat from the drift environment. An alternative conceptual model is also developed which evaluates the influence of water and water vapor mass transport on the ventilation efficiency. These effects are described using analytical methods which bound the contribution of latent heat to the system, quantify the effects of varying degrees of host rock saturation (and hence host rock thermal conductivity) on the ventilation efficiency, and evaluate the effects of vapor and enhanced vapor diffusion on the host rock thermal conductivity.

  2. 21 CFR 868.5955 - Intermittent mandatory ventilation attachment.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... false Intermittent mandatory ventilation attachment. 868.5955 Section...5955 Intermittent mandatory ventilation attachment. (a) Identification. An intermittent mandatory ventilation (IMV) attachment is a...

  3. 21 CFR 868.5955 - Intermittent mandatory ventilation attachment.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... false Intermittent mandatory ventilation attachment. 868.5955 Section...5955 Intermittent mandatory ventilation attachment. (a) Identification. An intermittent mandatory ventilation (IMV) attachment is a...

  4. 21 CFR 868.5955 - Intermittent mandatory ventilation attachment.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... false Intermittent mandatory ventilation attachment. 868.5955 Section...5955 Intermittent mandatory ventilation attachment. (a) Identification. An intermittent mandatory ventilation (IMV) attachment is a...

  5. 21 CFR 868.5955 - Intermittent mandatory ventilation attachment.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... false Intermittent mandatory ventilation attachment. 868.5955 Section...5955 Intermittent mandatory ventilation attachment. (a) Identification. An intermittent mandatory ventilation (IMV) attachment is a...

  6. 21 CFR 868.5955 - Intermittent mandatory ventilation attachment.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... false Intermittent mandatory ventilation attachment. 868.5955 Section...5955 Intermittent mandatory ventilation attachment. (a) Identification. An intermittent mandatory ventilation (IMV) attachment is a...

  7. Blood pressure control and components of the metabolic syndrome: the GOOD survey

    PubMed Central

    Zidek, Walter; Naditch-Brûlé, Lisa; Perlini, Stefano; Farsang, Csaba; Kjeldsen, Sverre E

    2009-01-01

    Background The GOOD (Global Cardiometabolic Risk Profile in Patients with Hypertension Disease) survey showed that blood pressure control was significantly worse in hypertensive patients with metabolic syndrome and/or diabetes mellitus than in those with essential hypertension only. This analysis aimed to investigate which components of the metabolic syndrome are primarily associated with poor blood pressure control. Methods The GOOD survey was designed as an observational cross-sectional survey in 12 European countries to assess the cardiometabolic risk profile in patients with essential hypertension. Investigators were randomly selected from a list of general practitioners (70% of investigators) and a list of specialists such as internists, cardiologists and hypertension specialists (30% of investigators). Data from 3,280 outpatients with hypertension, aged at least 30 years who were receiving antihypertensive treatment or had newly diagnosed hypertension according to the European Society of Hypertension and the European Society of Cardiology criteria, were included in the analyses. Blood pressure control, body mass index (BMI), waist circumference, serum triglycerides, total and high density lipoprotein (HDL) cholesterol measurements were compared in patients with diabetes mellitus and metabolic syndrome, with diabetes mellitus only, with metabolic syndrome only, and with neither metabolic syndrome nor diabetes mellitus. Results The highest blood pressure values were found in patients with metabolic syndrome with or without diabetes mellitus. Blood pressure was significantly lower in patients with diabetes mellitus only. The highest BMI, waist circumference and serum triglycerides, and the lowest HDL cholesterol levels among the groups studied occurred in patients with metabolic syndrome, either with or without diabetes mellitus. Conclusion Among the components of the metabolic syndrome, it is not impaired glucose tolerance which is associated with the poor response to antihypertensive treatment. Instead, visceral obesity and dyslipidemia components of the metabolic syndrome, i.e. hypertriglyceridemia and low HDL cholesterol levels, are associated with resistance to antihypertensive treatment. PMID:19754934

  8. Blood Pressure Control in Hypertensive Patients in the "Hiperdia Program": A Territory-Based Study

    PubMed Central

    de Souza, Clarita Silva; Stein, Airton Tetelbom; Bastos, Gisele Alsina Nader; Pellanda, Lucia Campos

    2014-01-01

    Background Systemic hypertension is highly prevalent and an important risk factor for cardiovascular events. Blood pressure control in hypertensive patients enrolled in the Hiperdia Program, a program of the Single Health System for the follow-up and monitoring of hypertensive patients, is still far below the desired level. Objective To describe the epidemiological profile and to assess blood pressure control of patients enrolled in Hiperdia, in the city of Novo Hamburgo (State of Rio Grande do Sul, Brazil). Methods Cross-sectional study with a stratified cluster random sample, including 383 adults enrolled in the Hiperdia Program of the 15 Basic Health Units of the city of Porto Alegre, conducted between 2010 and 2011. Controlled blood pressure was defined as ?140 mmHg × 90 mmHg. The hypertensive patients were interviewed and their blood pressure was measured using a calibrated aneroid device. Prevalence ratios (PR) with 95% confidence interval, Wald's ?2 test, and simple and multiple Poisson regression were used in the statistical analysis. Results The mean age was 63 ± 10 years, and most of the patients were females belonging to social class C, with a low level of education, a sedentary lifestyle, and family history positive for systemic hypertension. Diabetes mellitus (DM) was observed in 31%; adherence to the antihypertensive treatment in 54.3%; and 33.7% had their blood pressure controlled. DM was strongly associated with inadequate BP control, with only 15.7% of the diabetics showing BP considered as controlled. Conclusion Even for hypertensive patients enrolled in the Hiperdia Program, BP control is not satisfactorily reached or sustained. Diabetic hypertensive patients show the most inappropriate BP control. PMID:25004419

  9. When tight blood pressure control is not for everyone: a model for performance measurement in hypertension

    PubMed Central

    Steinman, Michael A.; Goldstein, Mary K.

    2010-01-01

    Background Many patients with hypertension have legitimate reasons to forego standard blood pressure targets yet are nonetheless included in performance measurement systems. An approach to performance measurement that incorporates clinical reasoning was developed to determine which patients to include in a performance measure for blood pressure control. Design A 10-member multispecialty advisory panel refined a taxonomy of situations in which the balance of benefits and harms of anti-hypertensive treatment do not clearly favor tight blood pressure control (blood pressure < 140/90). Results The panel identified several broad categories of reasons that could reasonably exempt a patient from performance measurement for blood pressure control. These included (1) patients who have suffered adverse effects from multiple classes of antihypertensive medications;(2) patients already taking ? 4 antihypertensive medications; (3) patients with terminal disease, moderate to severe dementia, or other conditions that overwhelmingly dominate the patient’s clinical status; and (4) other patient factors, including comfort care orientation and poor medication adherence despite attempts to remedy adherence difficulties. Several general principles also emerged. Performance measurement should focus on patients for whom the benefits of treatment clearly outweigh the harms and incorporate a longitudinal approach whereby clinicians are given a reasonable period of time to intervene on their patients with high blood pressure. In addition, the criteria for exempting a patient from performance measurement should be more strict in patients at higher risk of adverse health outcomes from hypertension, and more lenient for patients at lower risk. Conclusions Incorporating “real world” clinical principles and judgment into performance measurement systems may improve targeting of care and, by accounting for patient case-mix, allow for better comparison of performance between institutions. PMID:20402373

  10. ALTERNATIVE PROCESSING TECHNOLOGIES TO REDUCE TRANS ACID CONTENTS OF FOOD OILS: INTERESTERIFICATION, PLANT BREEDING, AND PRESSURE CONTROLLED HYDROGENATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alternative processing strategies to reduce trans acid contents of food oils include interesterification, genetic and plant breeding for triglyceride and fatty acid composition and pressure controlled hydrogenation. This paper will review research in these areas. Random interesterification of liqu...

  11. Adaptive support ventilation for faster weaning in COPD: a randomised controlled trial.

    PubMed

    Kirakli, C; Ozdemir, I; Ucar, Z Z; Cimen, P; Kepil, S; Ozkan, S A

    2011-10-01

    Adaptive support ventilation (ASV) is a closed-loop ventilation mode that can act both as pressure support ventilation (PSV) and pressure-controlled ventilation. Weaning with ASV shows promising results, mainly in post-cardiac surgery patients. The aim of the present randomised controlled study was to test the hypothesis that weaning with ASV could reduce the weaning duration in patients with chronic obstructive pulmonary disease (COPD) when compared with PSV. From among 435 COPD patients admitted to the intensive care unit (ICU) during a 20-month period, 97 were enrolled. Patients were assigned at random to either ASV or PSV as a weaning mode. Compared with PSV, ASV provided shorter weaning times (median 24 (interquartile range 20-62) h versus 72 (24-144) h, p=0.041) with similar weaning success rates (35 out of 49 for ASV and 33 out of 48 for PSV). Length of stay in the ICU was also shorter with ASV but the difference was not statistically significant. This study suggests that ASV may be used in the weaning of COPD patients with the advantage of shorter weaning times. Further studies are needed to investigate the role and potential advantages of ASV in the weaning period of different patient groups. PMID:21406514

  12. Residential ventilation standards scoping study

    SciTech Connect

    McKone, Thomas E.; Sherman, Max H.

    2003-10-01

    The goals of this scoping study are to identify research needed to develop improved ventilation standards for California's Title 24 Building Energy Efficiency Standards. The 2008 Title 24 Standards are the primary target for the outcome of this research, but this scoping study is not limited to that timeframe. We prepared this scoping study to provide the California Energy Commission with broad and flexible options for developing a research plan to advance the standards. This document presents the findings of a scoping study commissioned by the Public Interest Energy Research (PIER) program of the California Energy Commission to determine what research is necessary to develop new residential ventilation requirements for California. This study is one of three companion efforts needed to complete the job of determining the ventilation needs of California residences, determining the bases for setting residential ventilation requirements, and determining appropriate ventilation technologies to meet these needs and requirements in an energy efficient manner. Rather than providing research results, this scoping study identifies important research questions along with the level of effort necessary to address these questions and the costs, risks, and benefits of pursuing alternative research questions. In approaching these questions and corresponding levels of effort, feasibility and timing were important considerations. The Commission has specified Summer 2005 as the latest date for completing this research in time to update the 2008 version of California's Energy Code (Title 24).

  13. 33 CFR 183.620 - Natural ventilation system.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 2010-07-01 false Natural ventilation system. 183.620 Section...Ventilation § 183.620 Natural ventilation system. (a) Except for...open to the atmosphere, a natural ventilation system that meets the...

  14. 30 CFR 57.8532 - Opening and closing ventilation doors.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Opening and closing ventilation doors. 57.8532 Section 57...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Ventilation Underground Only § 57.8532 Opening and closing ventilation doors. When ventilation...

  15. 30 CFR 57.8532 - Opening and closing ventilation doors.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Opening and closing ventilation doors. 57.8532 Section 57...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Ventilation Underground Only § 57.8532 Opening and closing ventilation doors. When ventilation...

  16. 30 CFR 57.8532 - Opening and closing ventilation doors.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false Opening and closing ventilation doors. 57.8532 Section 57...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Ventilation Underground Only § 57.8532 Opening and closing ventilation doors. When ventilation...

  17. 30 CFR 57.8532 - Opening and closing ventilation doors.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Opening and closing ventilation doors. 57.8532 Section 57...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Ventilation Underground Only § 57.8532 Opening and closing ventilation doors. When ventilation...

  18. 30 CFR 57.8532 - Opening and closing ventilation doors.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Opening and closing ventilation doors. 57.8532 Section 57...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Ventilation Underground Only § 57.8532 Opening and closing ventilation doors. When ventilation...

  19. Human versus Computer Controlled Selection of Ventilator Settings: An Evaluation of Adaptive Support Ventilation and Mid-Frequency Ventilation

    PubMed Central

    Mireles-Cabodevila, Eduardo; Diaz-Guzman, Enrique; Arroliga, Alejandro C.; Chatburn, Robert L.

    2012-01-01

    Background. There are modes of mechanical ventilation that can select ventilator settings with computer controlled algorithms (targeting schemes). Two examples are adaptive support ventilation (ASV) and mid-frequency ventilation (MFV). We studied how different clinician-chosen ventilator settings are from these computer algorithms under different scenarios. Methods. A survey of critical care clinicians provided reference ventilator settings for a 70?kg paralyzed patient in five clinical/physiological scenarios. The survey-derived values for minute ventilation and minute alveolar ventilation were used as goals for ASV and MFV, respectively. A lung simulator programmed with each scenario's respiratory system characteristics was ventilated using the clinician, ASV, and MFV settings. Results. Tidal volumes ranged from 6.1 to 8.3?mL/kg for the clinician, 6.7 to 11.9?mL/kg for ASV, and 3.5 to 9.9?mL/kg for MFV. Inspiratory pressures were lower for ASV and MFV. Clinician-selected tidal volumes were similar to the ASV settings for all scenarios except for asthma, in which the tidal volumes were larger for ASV and MFV. MFV delivered the same alveolar minute ventilation with higher end expiratory and lower end inspiratory volumes. Conclusions. There are differences and similarities among initial ventilator settings selected by humans and computers for various clinical scenarios. The ventilation outcomes are the result of the lung physiological characteristics and their interaction with the targeting scheme. PMID:23119152

  20. Predictors to parental knowledge about childhood immunisation/EPI vaccines in two health districts in Cameroon prior to the introduction of 13-valent Pneumococcal Conjugate Vaccines (PCV-13)

    PubMed Central

    Libwea, John Njuma; Kobela, Marie; Ollgren, Jukka; Emah, Irene; Tchio, Robert; Nohynek, Hanna

    2014-01-01

    Introduction Pneumonia is vaccine-preventable, but the increasing death toll resulting from the disease in Sub-Saharan Africa is alarming. Several factors account for vaccine failing to reach every child, besides incomplete vaccine coverage. Most of these include the perceptions of parents/guardians and healthcare providers. Previous studies on the introduction of new vaccines have focused on experimental trials, coverage figures and vaccine efficacy in developed countries. Little is known on the factors which may hinder the implementation process despite the huge challenges this may encounter in developing countries. This study described the knowledge, attitude and practices (KAP) of parents/guardians on pneumonia and immunisations/EPI vaccines; identify predictive parental socio-economic/demographic characteristics that of good knowledge on pneumonia infections, routine EPI vaccines and the PCV-13. Finally, the study described health center personnel perceptions about immunisations. Methods The WHO's immunisation coverage cluster survey design was used, involving parents/guardians (n = 205) of children aged 0-59 months and health centre personnel (n = 13) directly concerned with vaccination activities between July-September 2010 in two health districts in Yaounde, Cameroon. Descriptive statistics and multivariate logistic models were used to analyse the parental/guardian data while the health personnel data was only analysed descriptively using SPSS version 17.0. Results Only 19% of the parents/guardians were aware of the availability of the PCV-13. Logistic modelling identified important associations between parental socio-economic/demographic factors and good knowledge on pneumonia disease burden and prevention. Conclusion According to parents/guardians a short and clear message on the dangers of pneumonia and the need for prevention provided to parents/guardians during sensitisation/out-reach campaigns and use of social network avenues would be primordial, if the PCV-13 is to reach every child. PMID:25396013

  1. Heating, Ventilation, and Air Conditioning Design

    E-print Network

    .................................................................................................5 3 HVAC Design and Implementation ...............Heating, Ventilation, and Air Conditioning Design Strategy for a Hot-Humid Production Builder P% postconsumer waste #12;iii Heating, Ventilation, and Air Conditioning Design Strategy for a Hot

  2. Energy Recovery Ventilator Membrane Efficiency Testing 

    E-print Network

    Rees, Jennifer Anne

    2013-05-07

    A test setup was designed and built to test energy recovery ventilator membranes. The purpose of this test setup was to measure the heat transfer and water vapor transfer rates through energy recover ventilator membranes and find their effectiveness...

  3. 46 CFR 111.103-1 - Power ventilation systems except machinery space ventilation systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Remote Stopping Systems § 111.103-1 Power ventilation systems except machinery space ventilation systems. Each power ventilation system must... with the controls for every power ventilation system to which this section is applicable; and (b)...

  4. We compared the efficacy of positive pressure ventilation (PPV) vs negative pressure ventilation (NPV) in providing

    E-print Network

    Shadmehr, Reza

    We compared the efficacy of positive pressure ventilation (PPV) vs negative pressure ventilationEMG), minute ventilation (VE),tidal volume (VT), and end-tidal CO (etCOÃ during 15 minutes of PPV and NPV. For each subject, ventilator adjustments were made to obtain VE similar to levels measured during quiet

  5. Fracture ventilation by surface winds

    NASA Astrophysics Data System (ADS)

    Nachshon, U.; Dragila, M. I.; Weisbrod, N.

    2011-12-01

    Gas exchange between the Earth subsurface and the atmosphere is an important mechanism, affecting hydrological, agricultural and environmental processes. From a hydrological aspect, water vapor transport is the most important process related to Earth-atmosphere gas exchange. In respect to agriculture, gas transport in the upper soil profile is important for soil aeration. From an environmental aspect, emission of volatile radionuclides, such as 3H, 14C and Rd from radioactive waste disposal facilities; volatile organic components from industrial sources and Rn from natural sources, all found in the upper vadose zone, can greatly affect public health when emissions occur in populated areas. Thus, it is vital to better understand gas exchange processes between the Earth's upper crust and atmosphere. Four major mechanisms are known to transfer gases between ground surface and atmosphere: (1) Diffusion; (2) Pressure gradients between ground pores and atmosphere due to changes in barometric pressure; (3) Density-driven gas flow in respond to thermal gradients in the ground; and (4) Winds above the ground surface. Herein, the wind ventilation mechanism is studied. Whereas the wind's impact on ground ventilation was explored in several studies, the physical mechanisms governing this process were hardly quantified or characterized. In this work the physical properties of fracture ventilation due to wind blowing along land surface were explored and quantified. Both field measurements and Hele-Shaw experiments under controlled conditions in the laboratory were used to study this process. It was found that winds in the range of 0.3 m/s result in fracture ventilation down to a depth of 0.2 m. As wind velocity increases, the depth of the ventilation inside the fracture increases respectively, in a linear manner. In addition, the fracture aperture also affects the depth of ventilation, which grows as fracture aperture increases. For the maximal examined aperture of 2 cm and wind velocity of 1.25 m/s, fracture ventilation was deeper than 0.45 m. This study sheds new light on fracture ventilation, showing that moderate winds may increase evaporation and gas exchange between fractured media and the atmosphere. Even though wind impact is limited to the top 0.5 m below the ground surface, it is an important process as most of the biological activities, as well as important hydrological processes occur in this region. Wind effect should be considered when modeling mass and energy balances between the Earth upper crust and atmosphere.

  6. 30 CFR 75.333 - Ventilation controls.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Ventilation controls. 75.333 Section 75.333 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.333 Ventilation controls. (a) For purposes of this section, “doors” include...

  7. Speech for People with Tracheostomies or Ventilators

    MedlinePLUS

    ... the Public / Speech, Language and Swallowing / Disorders and Diseases Speech for People With Tracheostomies or Ventilators [ en Español ] ... What impact does having a ventilator have on speech? For some people, a ... may need to be connected to a breathing machine (ventilator) that provides a ...

  8. 46 CFR 42.15-45 - Ventilators.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Ventilators. 42.15-45 Section 42.15-45 Shipping COAST... Conditions of Assignment of Freeboard § 42.15-45 Ventilators. (a) Ventilators in position 1 or 2 to spaces... extend to more than 7.5 feet above the deck, need not be fitted with closing arrangements...

  9. 46 CFR 42.15-45 - Ventilators.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Ventilators. 42.15-45 Section 42.15-45 Shipping COAST... Conditions of Assignment of Freeboard § 42.15-45 Ventilators. (a) Ventilators in position 1 or 2 to spaces... extend to more than 7.5 feet above the deck, need not be fitted with closing arrangements...

  10. 46 CFR 111.15-10 - Ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... REQUIREMENTS Storage Batteries and Battery Chargers: Construction and Installation § 111.15-10 Ventilation. (a) General. Each room, locker, and box for storage batteries must be arranged or ventilated to prevent... with the battery charger so that the battery cannot be charged without ventilation. (c) Large...

  11. 46 CFR 111.15-10 - Ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... REQUIREMENTS Storage Batteries and Battery Chargers: Construction and Installation § 111.15-10 Ventilation. (a) General. Each room, locker, and box for storage batteries must be arranged or ventilated to prevent... with the battery charger so that the battery cannot be charged without ventilation. (c) Large...

  12. 46 CFR 111.15-10 - Ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... REQUIREMENTS Storage Batteries and Battery Chargers: Construction and Installation § 111.15-10 Ventilation. (a) General. Each room, locker, and box for storage batteries must be arranged or ventilated to prevent... with the battery charger so that the battery cannot be charged without ventilation. (c) Large...

  13. 46 CFR 111.15-10 - Ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... REQUIREMENTS Storage Batteries and Battery Chargers: Construction and Installation § 111.15-10 Ventilation. (a) General. Each room, locker, and box for storage batteries must be arranged or ventilated to prevent... with the battery charger so that the battery cannot be charged without ventilation. (c) Large...

  14. 46 CFR 111.15-10 - Ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... REQUIREMENTS Storage Batteries and Battery Chargers: Construction and Installation § 111.15-10 Ventilation. (a) General. Each room, locker, and box for storage batteries must be arranged or ventilated to prevent... with the battery charger so that the battery cannot be charged without ventilation. (c) Large...

  15. 46 CFR 168.15-50 - Ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Ventilation. 168.15-50 Section 168.15-50 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS CIVILIAN NAUTICAL SCHOOL VESSELS Accommodations § 168.15-50 Ventilation. (a) All quarters must be adequately ventilated in a manner suitable...

  16. 46 CFR 168.15-50 - Ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Ventilation. 168.15-50 Section 168.15-50... Accommodations § 168.15-50 Ventilation. (a) All quarters must be adequately...the vessel. (b) When mechanical ventilation is provided for sleeping rooms,...

  17. 46 CFR 194.15-5 - Ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Ventilation. 194.15-5 Section 194.15-5...Scientific Laboratory § 194.15-5 Ventilation. (a) Operations, reactions...equipped with an independent power exhaust ventilation system which terminates so as to...

  18. 46 CFR 72.05-50 - Ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Ventilation. 72.05-50 Section 72.05-50...Structural Fire Protection § 72.05-50 Ventilation. (a) Where the term duct is...trunks, plenums, and any other type of ventilation piping, chambers, or...

  19. 9 CFR 91.21 - Ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Ventilation. 91.21 Section 91.21 Animals...Vessels and Accommodations § 91.21 Ventilation. Each underdeck compartment on...equipped with a system of mechanical ventilation that will furnish a complete...

  20. 46 CFR 194.15-5 - Ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false Ventilation. 194.15-5 Section 194.15-5...Scientific Laboratory § 194.15-5 Ventilation. (a) Operations, reactions...equipped with an independent power exhaust ventilation system which terminates so as to...

  1. 46 CFR 72.05-50 - Ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Ventilation. 72.05-50 Section 72.05-50...Structural Fire Protection § 72.05-50 Ventilation. (a) Where the term duct is...trunks, plenums, and any other type of ventilation piping, chambers, or...

  2. 46 CFR 168.15-50 - Ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false Ventilation. 168.15-50 Section 168.15-50... Accommodations § 168.15-50 Ventilation. (a) All quarters must be adequately...the vessel. (b) When mechanical ventilation is provided for sleeping rooms,...

  3. 9 CFR 91.21 - Ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Ventilation. 91.21 Section 91.21 Animals...Vessels and Accommodations § 91.21 Ventilation. Each underdeck compartment on...equipped with a system of mechanical ventilation that will furnish a complete...

  4. 46 CFR 168.15-50 - Ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Ventilation. 168.15-50 Section 168.15-50... Accommodations § 168.15-50 Ventilation. (a) All quarters must be adequately...the vessel. (b) When mechanical ventilation is provided for sleeping rooms,...

  5. 46 CFR 194.15-5 - Ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Ventilation. 194.15-5 Section 194.15-5...Scientific Laboratory § 194.15-5 Ventilation. (a) Operations, reactions...equipped with an independent power exhaust ventilation system which terminates so as to...

  6. 46 CFR 168.15-50 - Ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Ventilation. 168.15-50 Section 168.15-50... Accommodations § 168.15-50 Ventilation. (a) All quarters must be adequately...the vessel. (b) When mechanical ventilation is provided for sleeping rooms,...

  7. 46 CFR 194.15-5 - Ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Ventilation. 194.15-5 Section 194.15-5...Scientific Laboratory § 194.15-5 Ventilation. (a) Operations, reactions...equipped with an independent power exhaust ventilation system which terminates so as to...

  8. 9 CFR 91.21 - Ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Ventilation. 91.21 Section 91.21 Animals...Vessels and Accommodations § 91.21 Ventilation. Each underdeck compartment on...equipped with a system of mechanical ventilation that will furnish a complete...

  9. 46 CFR 194.15-5 - Ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Ventilation. 194.15-5 Section 194.15-5...Scientific Laboratory § 194.15-5 Ventilation. (a) Operations, reactions...equipped with an independent power exhaust ventilation system which terminates so as to...

  10. 9 CFR 91.21 - Ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Ventilation. 91.21 Section 91.21 Animals...Vessels and Accommodations § 91.21 Ventilation. Each underdeck compartment on...equipped with a system of mechanical ventilation that will furnish a complete...

  11. 14 CFR 23.831 - Ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Ventilation. 23.831 Section 23.831 Aeronautics...Cargo Accommodations § 23.831 Ventilation. Link to an amendment published...set forth as follows: § 23.831 Ventilation. (c) For jet pressurized...

  12. 46 CFR 72.05-50 - Ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Ventilation. 72.05-50 Section 72.05-50...Structural Fire Protection § 72.05-50 Ventilation. (a) Where the term duct is...trunks, plenums, and any other type of ventilation piping, chambers, or...

  13. May 1999 LBNL -42975 ASHRAE'S RESIDENTIAL VENTILATION

    E-print Network

    May 1999 LBNL - 42975 ASHRAE'S RESIDENTIAL VENTILATION STANDARD: EXEGESIS OF PROPOSED STANDARD 62 Committee on "Ventilation and Acceptable Indoor Air Quality in Low-Rise Residential Buildings", SPC 62.2P, approved ASHRAE's first complete standard on residential ventilation for public review

  14. 46 CFR 72.05-50 - Ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false Ventilation. 72.05-50 Section 72.05-50...Structural Fire Protection § 72.05-50 Ventilation. (a) Where the term duct is...trunks, plenums, and any other type of ventilation piping, chambers, or...

  15. 46 CFR 72.05-50 - Ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Ventilation. 72.05-50 Section 72.05-50...Structural Fire Protection § 72.05-50 Ventilation. (a) Where the term duct is...trunks, plenums, and any other type of ventilation piping, chambers, or...

  16. 9 CFR 91.21 - Ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Ventilation. 91.21 Section 91.21 Animals...Vessels and Accommodations § 91.21 Ventilation. Each underdeck compartment on...equipped with a system of mechanical ventilation that will furnish a complete...

  17. Independent Orbiter Assessment (IOA): Assessment of the atmospheric revitalization pressure control subsystem FMEA/CIL

    NASA Technical Reports Server (NTRS)

    Saiidi, M. J.

    1988-01-01

    The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA effort first completed an analysis of the atmospheric Revitalization Pressure Control Subsystem (ARPCS) hardware, generating draft failure modes and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The IOA results were then compared to the NASA FMEA/CIL proposed Post 51-L updates based upon the CCB/PRCB presentations and an informal criticality summary listing. A discussion of each discrepancy from the comparison is provided through additional analysis as required. These discrepancies were flagged as issues, and recommendations were made based on the FMEA data available at the time. This report documents the results of that comparison for the Orbiter ARPCS hardware.

  18. Crystal growth by a modified vapor pressure-controlled Czochralski (VCz) technique

    NASA Astrophysics Data System (ADS)

    Neubert, M.; Rudolph, P.; Frank-Rotsch, Ch.; Czupalla, M.; Trompa, K.; Pietsch, M.; Jurisch, M.; Eichler, St.; Weinert, B.; Scheffer-Czygan, M.

    2008-04-01

    A modified vapor pressure-controlled Czochralski (VCz) method is reported which employs a diving bell around the growing crystal. Semi-insulating (SI) GaAs crystals with a diameter of 160 mm and an overall length up to 220 mm were grown from melts of up to 23 kg, and compared with similar-sized crystals grown using a standard liquid-encapsulation Czochralski (LEC) process. Optimization of the VCz process was assisted by global numerical simulations. A slightly convex growth interface has been found to be the most suitable one for achieving a relatively low EPD of ˜10 4 cm -2, with an associated reduction in the probability of dislocation bunching. The carbon concentration of the crystals was controlled down to values of 10 14 cm -3. The electrical properties, including the EL2° content are discussed.

  19. Development of an expert system for analysis of Shuttle atmospheric revitalization and pressure control subsystem anomalies

    NASA Technical Reports Server (NTRS)

    Lafuse, Sharon A.

    1991-01-01

    The paper describes the Shuttle Leak Management Expert System (SLMES), a preprototype expert system developed to enable the ECLSS subsystem manager to analyze subsystem anomalies and to formulate flight procedures based on flight data. The SLMES combines the rule-based expert system technology with the traditional FORTRAN-based software into an integrated system. SLMES analyzes the data using rules, and, when it detects a problem that requires simulation, it sets up the input for the FORTRAN-based simulation program ARPCS2AT2, which predicts the cabin total pressure and composition as a function of time. The program simulates the pressure control system, the crew oxygen masks, the airlock repress/depress valves, and the leakage. When the simulation has completed, other SLMES rules are triggered to examine the results of simulation contrary to flight data and to suggest methods for correcting the problem. Results are then presented in form of graphs and tables.

  20. Effect of Residual Noncondensables on Pressurization and Pressure Control of a Zero-Boil-Off Tank in Microgravity

    NASA Technical Reports Server (NTRS)

    Kassemi, Mohammad; Hylton, Sonya; Kartizova, Olga

    2013-01-01

    The Zero-Boil-Off Tank (ZBOT) Experiment is a small-scale experiment that uses a transparent ventless Dewar and a transparent simulant phase-change fluid to study sealed tank pressurization and pressure control with applications to on-surface and in-orbit storage of propellant cryogens. The experiment will be carried out under microgravity conditions aboard the International Space Station in the 2014 timeframe. This paper presents preliminary results from ZBOT's ground-based research that focuses on the effects of residual noncondensable gases in the ullage on both pressurization and pressure reduction trends in the sealed Dewar. Tank pressurization is accomplished through heating of the test cell wall in the wetted and un-wetted regions simultaneously or separately. Pressure control is established through mixing and destratification of the bulk liquid using a temperature controlled forced jet flow with different degrees of liquid jet subcooling. A Two-Dimensional axisymmetric two-phase CFD model for tank pressurization and pressure control is also presented. Numerical prediction of the model are compared to experimental 1g results to both validate the model and also indicate the effect of the noncondensable gas on evolution of pressure and temperature distributions in the ullage during pressurization and pressure control. Microgravity simulations case studies are also performed using the validated model to underscore and delineate the profound effect of the noncondensables on condensation rates and interfacial temperature distributions with serious implications for tank pressure control in reduced gravity.

  1. Tank Pressure Control Experiment: Thermal Phenomena in Microgravity. Video 3 of 4

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The report presents the results of the flight experiment Tank Pressure Control Experiment/Thermal Phenomena (TPCE/TP) performed in the microgravity environment of the space shuttle. TPCE/TP, flown on the Space Transportation System STS-52, was a second flight of the Tank Pressure Control Experiment (TPCE). The experiment used Freon 113 at near saturation conditions. The test tank was filled with liquid to about 83 percent by volume. The experiment consisted of 21 tests. Each test generally started with a heating phase to increase the tank pressure and to develop temperature stratification in the fluid, followed by a fluid mixing phase for the tank pressure reduction and fluid temperature equilibration. The heating phase provided pool boiling data from large (relative to bubble sizes) heating surfaces (0.1046 m by 0.0742 m) at low heat fluxes (0.23 to 1.16 kW/m(exp 2)). The system pressure and the bulk liquid subcooling varied from 39 to 78 kPa and 1 to 3 deg C, respectively. The boiling process during the entire heating period, as well a jet-induced mixing process for the first 2 min. of the mixing period, was also recorded on video. Analyses of data from the two flight experiments (TPCE and TPCE/TP) and their comparison with the results obtained in drop tower experiments suggest that as Bond number approaches zero the flow pattern produced by an axial jet and the mixing time can be predicted by the Weber number. This is video 3 of 4.

  2. Tank Pressure Control Experiment: Thermal Phenomena in Microgravity. Video 4 of 4

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The report presents the results of the flight experiment Tank Pressure Control Experiment/Thermal Phenomena (TPCE/TP) performed in the microgravity environment of the space shuttle. TPCE/TP, flown on the Space Transportation System STS-52, was a second flight of the Tank Pressure Control Experiment (TPCE). The experiment used Freon 113 at near saturation conditions. The test tank was filled with liquid to about 83 percent by volume. The experiment consisted of 21 tests. Each test generally started with a heating phase to increase the tank pressure and to develop temperature stratification in the fluid, followed by a fluid mixing phase for the tank pressure reduction and fluid temperature equilibration. The heating phase provided pool boiling data from large (relative to bubble sizes) heating surfaces (0.1046 m by 0.0742 m) at low heat fluxes (0.23 to 1.16 kW/m(exp 2)). The system pressure and the bulk liquid subcooling varied from 39 to 78 kPa and 1 to 3 deg C, respectively. The boiling process during the entire heating period, as well a jet-induced mixing process for the first 2 min. of the mixing period, was also recorded on video. Analyses of data from the two flight experiments (TPCE and TPCE/TP) and their comparison with the results obtained in drop tower experiments suggest that as Bond number approaches zero the flow pattern produced by an axial jet and the mixing time can be predicted by the Weber number. This is video 4 of 4.

  3. Tank Pressure Control Experiment: Thermal Phenomena in Microgravity. Video 1 of 4

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The report presents the results of the flight experiment Tank Pressure Control Experiment/Thermal Phenomena (TPCE/TP) performed in the microgravity environment of the space shuttle. TPCE/TP, flown on the Space Transportation System STS-52, was a second flight of the Tank Pressure Control Experiment (TPCE). The experiment used Freon 113 at near saturation conditions. The test tank was filled with liquid to about 83 percent by volume. The experiment consisted of 21 tests. Each test generally started with a heating phase to increase the tank pressure and to develop temperature stratification in the fluid, followed by a fluid mixing phase for the tank pressure reduction and fluid temperature equilibration. The heating phase provided pool boiling data from large (relative to bubble sizes) heating surfaces (0.1046 m by 0.0742 m) at low heat fluxes (0.23 to 1.16 kW/m(exp 2)). The system pressure and the bulk liquid subcooling varied from 39 to 78 kPa and 1 to 3 deg C, respectively. The boiling process during the entire heating period, as well a jet-induced mixing process for the first 2 min. of the mixing period, was also recorded on video. Analyses of data from the two flight experiments (TPCE and TPCE/TP) and their comparison with the results obtained in drop tower experiments suggest that as Bond number approaches zero the flow pattern produced by an axial jet and the mixing time can be predicted by the Weber number. This is video 1 of 4.

  4. Tank Pressure Control Experiment: Thermal Phenomena in Microgravity. Video 2 of 4

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The report presents the results of the flight experiment Tank Pressure Control Experiment/Thermal Phenomena (TPCE/TP) performed in the microgravity environment of the space shuttle. TPCE/TP, flown on the Space Transportation System STS-52, was a second flight of the Tank Pressure Control Experiment (TPCE). The experiment used Freon 113 at near saturation conditions. The test tank was filled with liquid to about 83 percent by volume. The experiment consisted of 21 tests. Each test generally started with a heating phase to increase the tank pressure and to develop temperature stratification in the fluid, followed by a fluid mixing phase for the tank pressure reduction and fluid temperature equilibration. The heating phase provided pool boiling data from large (relative to bubble sizes) heating surfaces (0.1046 m by 0.0742 m) at low heat fluxes (0.23 to 1.16 kW/m(exp 2)). The system pressure and the bulk liquid subcooling varied from 39 to 78 kPa and 1 to 3 deg C, respectively. The boiling process during the entire heating period, as well a jet-induced mixing process for the first 2 min. of the mixing period, was also recorded on video. Analyses of data from the two flight experiments (TPCE and TPCE/TP) and their comparison with the results obtained in drop tower experiments suggest that as Bond number approaches zero the flow pattern produced by an axial jet and the mixing time can be predicted by the Weber number. This is video 2 of 4.

  5. Preventing Ventilation On Sailboard Skegs

    NASA Technical Reports Server (NTRS)

    Caldwell, Richard A.

    1990-01-01

    Design effort undertaken to solve spinout problem plaguing high-performance sailboards. Proposed skeg section designed by use of computer model of pressure field and boundary layer. Prevents ventilation by maintaining attached boundary-layer flow throughout operating environment. Cavitation also avoided by preventing valleys in pressure distribution while skeg operated throughout its range.

  6. The basis and basics of mechanical ventilation.

    PubMed

    Bone, R C; Eubanks, D H

    1991-06-01

    The development of mechanical ventilators and the procedures for their application began with the simple foot pump developed by Fell O'Dwyer in 1888. Ventilators have progressed through three generations, beginning with intermittent positive pressure breathing units such as the Bird and Bennett device in the 1960s. These were followed by second-generation units--represented by the Bennett MA-2 ventilator--in the 1970s, and the third-generation microprocessor-controlled units of today. During this evolutionary process clinicians recognized Types I and II respiratory failure as being indicators for mechanical ventilatory support. More recently investigators have expanded, clarified, and clinically applied the physiology of the work of breathing (described by Julius Comroe and other pioneers) to muscle fatigue, requiring ventilatory support. A ventilator classification system can help the clinician understand how ventilators function and under what conditions they may fail to operate as desired. Pressure-support ventilation is an example of how industry has responded to a clinical need--that is, to unload the work of breathing. All positive pressure ventilators generate tidal volumes by using power sources such as medical gas cylinders, air compressors, electrically driven turbines, or piston driven motors. Positive end-expiratory pressures, synchronized intermittent mandatory ventilation, pressure support ventilation, pressure release ventilation, and mandatory minute ventilation, are examples of the special functions available on modern ventilators. Modern third-generation ventilators use microprocessors to control operational functions and monitors. Because these units have incorporated the experience learned from earlier ventilators, it is imperative that clinicians understand basic ventilator operation and application in order to most effectively prescribe and assess their use. PMID:2036934

  7. Numerical study of variable lung ventilation strategies

    E-print Network

    Yadav, Reena; Hiremath, Kirankumar; Bagler, Ganesh

    2015-01-01

    Mechanical ventilation is used for patients with a variety of lung diseases. Traditionally, ventilators have been designed to monotonously deliver equal sized breaths. While it may seem intuitive that lungs may benefit from unvarying and stable ventilation pressure strategy, recently it has been reported that variable lung ventilation is advantageous. In this study, we analyze the mean tidal volume in response to different `variable ventilation pressure' strategies. We found that uniformly distributed variability in pressure gives the best tidal volume as compared to that of normal, scale- free, log normal and linear distributions.

  8. Night ventilation control strategies in office buildings

    SciTech Connect

    Wang, Zhaojun; Yi, Lingli; Gao, Fusheng

    2009-10-15

    In moderate climates night ventilation is an effective and energy-efficient approach to improve the indoor thermal environment for office buildings during the summer months, especially for heavyweight construction. However, is night ventilation a suitable strategy for office buildings with lightweight construction located in cold climates? In order to answer this question, the whole energy-consumption analysis software EnergyPlus was used to simulate the indoor thermal environment and energy consumption in typical office buildings with night mechanical ventilation in three cities in northern China. The summer outdoor climate data was analyzed, and three typical design days were chosen. The most important factors influencing night ventilation performance such as ventilation rates, ventilation duration, building mass and climatic conditions were evaluated. When night ventilation operation time is closer to active cooling time, the efficiency of night ventilation is higher. With night ventilation rate of 10 ach, the mean radiant temperature of the indoor surface decreased by up to 3.9 C. The longer the duration of operation, the more efficient the night ventilation strategy becomes. The control strategies for three locations are given in the paper. Based on the optimized strategies, the operation consumption and fees are calculated. The results show that more energy is saved in office buildings cooled by a night ventilation system in northern China than ones that do not employ this strategy. (author)

  9. Liquid ventilation: it's not science fiction anymore.

    PubMed

    Norris, M K; Fuhrman, B P; Leach, C L

    1994-08-01

    Liquid ventilation is, by all initial considerations, an unconventional concept. Decades of research, however, have found that by using perfluorocarbons, which are capable of holding high concentrations of critical gases such as oxygen and carbon dioxide, gas exchange optimal enough to support life is possible with no known toxic effects. The earliest method of liquid ventilation, tidal liquid breathing, involved infusion and active removal of tidal volumes of perfluorocarbons by a liquid ventilator for gas exchange. Recently, a new method of partial liquid breathing, called perfluorocarbon-associated gas exchange, makes the process of liquid ventilation simpler by using conventional gas ventilators. Current research is showing great promise in the use of liquid ventilation for patients with pulmonary pathology. Critical care nurses should become knowledgeable of this new mode of ventilation and be prepared to meet the special needs of this unique population. PMID:7780839

  10. Summary of human responses to ventilation

    SciTech Connect

    Seppanen, Olli A.; Fisk, William J.

    2004-06-01

    The effects of ventilation on indoor air quality and health is a complex issue. It is known that ventilation is necessary to remove indoor generated pollutants from indoor air or dilute their concentration to acceptable levels. But, as the limit values of all pollutants are not known, the exact determination of required ventilation rates based on pollutant concentrations and associated risks is seldom possible. The selection of ventilation rates has to be based also on epidemiological research (e.g. Seppanen et al., 1999), laboratory and field experiments (e.g. CEN 1996, Wargocki et al., 2002a) and experience (e.g. ECA 2003). Ventilation may also have harmful effects on indoor air quality and climate if not properly designed, installed, maintained and operated as summarized by Seppdnen (2003). Ventilation may bring indoors harmful substances that deteriorate the indoor environment. Ventilation also affects air and moisture flow through the building envelope and may lead to moisture problems that deteriorate the structures of the building. Ventilation changes the pressure differences over the structures of building and may cause or prevent the infiltration of pollutants from structures or adjacent spaces. Ventilation is also in many cases used to control the thermal environment or humidity in buildings. Ventilation can be implemented with various methods which may also affect health (e.g. Seppdnen and Fisk, 2002, Wargocki et al., 2002a). In non residential buildings and hot climates, ventilation is often integrated with air-conditioning which makes the operation of ventilation system more complex. As ventilation is used for many purposes its health effects are also various and complex. This paper summarizes the current knowledge on positive and negative effects of ventilation on health and other human responses. The focus of the paper is on office-type working environment and residential buildings. In the industrial premises the problems of air quality are usually more complex and case specific. They are subject to occupational safety legislation and not discussed here.

  11. Improved OCT imaging of lung tissue using a prototype for total liquid ventilation

    NASA Astrophysics Data System (ADS)

    Schnabel, Christian; Meissner, Sven; Koch, Edmund

    2011-06-01

    Optical coherence tomography (OCT) is used for imaging subpleural alveoli in animal models to gain information about dynamic and morphological changes of lung tissue during mechanical ventilation. The quality of OCT images can be increased if the refraction index inside the alveoli is matched to the one of tissue via liquid-filling. Thereby, scattering loss can be decreased and higher penetration depth and tissue contrast can be achieved. Until now, images of liquid-filled lungs were acquired in isolated and fixated lungs only, so that an in vivo measurement situation is not present. To use the advantages of liquid-filling for in vivo imaging of small rodent lungs, it was necessary to develop a liquid ventilator. Perfluorodecalin, a perfluorocarbon, was selected as breathing fluid because of its refraction index being similar to the one of water and the high transport capacity for carbon dioxide and oxygen. The setup is characterized by two independent syringe pumps to insert and withdraw the fluid into and from the lung and a custom-made control program for volume- or pressure-controlled ventilation modes. The presented results demonstrate the liquid-filling verified by optical coherence tomography and intravital microscopy (IVM) and the advantages of liquid-filling to OCT imaging of subpleural alveoli.

  12. Constant pressure-controlled extrusion method for the preparation of Nano-sized lipid vesicles.

    PubMed

    Morton, Leslie A; Saludes, Jonel P; Yin, Hang

    2012-01-01

    Liposomes are artificially prepared vesicles consisting of natural and synthetic phospholipids that are widely used as a cell membrane mimicking platform to study protein-protein and protein-lipid interactions, monitor drug delivery, and encapsulation. Phospholipids naturally create curved lipid bilayers, distinguishing itself from a micelle. Liposomes are traditionally classified by size and number of bilayers, i.e. large unilamellar vesicles (LUVs), small unilamellar vesicles (SUVs) and multilamellar vesicles (MLVs). In particular, the preparation of homogeneous liposomes of various sizes is important for studying membrane curvature that plays a vital role in cell signaling, endo- and exocytosis, membrane fusion, and protein trafficking. Several groups analyze how proteins are used to modulate processes that involve membrane curvature and thus prepare liposomes of diameters <100 - 400 nm to study their behavior on cell functions. Others focus on liposome-drug encapsulation, studying liposomes as vehicles to carry and deliver a drug of interest. Drug encapsulation can be achieved as reported during liposome formation. Our extrusion step should not affect the encapsulated drug for two reasons, i.e. (1) drug encapsulation should be achieved prior to this step and liposomes should retain their natural biophysical stability, securely carrying the drug in the aqueous core. These research goals further suggest the need for an optimized method to design stable sub-micron lipid vesicles. Nonetheless, the current liposome preparation technologies (sonication, freeze-and-thaw, sedimentation) do not allow preparation of liposomes with highly curved surface (i.e. diameter <100 nm) with high consistency and efficiency, which limits the biophysical studies of an emerging field of membrane curvature sensing. Herein, we present a robust preparation method for a variety of biologically relevant liposomes. Manual extrusion using gas-tight syringes and polycarbonate membranes, is a common practice but heterogeneity is often observed when using pore sizes <100 nm due to due to variability of manual pressure applied. We employed a constant pressure-controlled extrusion apparatus to prepare synthetic liposomes whose diameters range between 30 and 400 nm. Dynamic light scattering (DLS), electron microscopy and nanoparticle tracking analysis (NTA) were used to quantify the liposome sizes as described in our protocol, with commercial polystyrene (PS) beads used as a calibration standard. A near linear correlation was observed between the employed pore sizes and the experimentally determined liposomes, indicating high fidelity of our pressure-controlled liposome preparation method. Further, we have shown that this lipid vesicle preparation method is generally applicable, independent of various liposome sizes. Lastly, we have also demonstrated in a time course study that these prepared liposomes were stable for up to 16 hours. A representative nano-sized liposome preparation protocol is demonstrated below. PMID:22760481

  13. Development of a Residential Integrated Ventilation Controller

    SciTech Connect

    Staff Scientist; Walker, Iain; Sherman, Max; Dickerhoff, Darryl

    2011-12-01

    The goal of this study was to develop a Residential Integrated Ventilation Controller (RIVEC) to reduce the energy impact of required mechanical ventilation by 20percent, maintain or improve indoor air quality and provide demand response benefits. This represents potential energy savings of about 140 GWh of electricity and 83 million therms of natural gas as well as proportional peak savings in California. The RIVEC controller is intended to meet the 2008 Title 24 requirements for residential ventilation as well as taking into account the issues of outdoor conditions, other ventilation devices (including economizers), peak demand concerns and occupant preferences. The controller is designed to manage all the residential ventilation systems that are currently available. A key innovation in this controller is the ability to implement the concept of efficacy and intermittent ventilation which allows time shifting of ventilation. Using this approach ventilation can be shifted away from times of high cost or high outdoor pollution towards times when it is cheaper and more effective. Simulations, based on the ones used to develop the new residential ventilation requirements for the California Buildings Energy code, were used to further define the specific criteria and strategies needed for the controller. These simulations provide estimates of the energy, peak power and contaminant improvement possible for different California climates for the various ventilation systems. Results from a field test of the prototype controller corroborate the predicted performance.

  14. Modeling results of the high temperature pressure-controlled atomization process (PCAP)

    SciTech Connect

    Lee, Y.M.

    1994-12-31

    The Pressure-Controlled Atomization Process (PCAP) is a thermal spray process that atomizes liquid metals in the flow of a converging-diverging nozzle. The subsonic/transonic/supersonic two-phase gas (with droplets) flows through a nozzle and subsequent subsonic free jet flow from the nozzle to the sprayed surface, provides a particular method used in spray forming/coating technology. In this study, a quasi-one-dimensional model is used to simulate the entire converging-diverging nozzle flow field (with particle injection at the throat) and the plume (free jet) region. The basic numerical technique and computer model solve the steady gas field equations through a conservative variable approach and treat the droplet phase in a Lagrangian manner with full aerodynamic and energetic coupling between the droplets and the transport gas handled via source terms. The liquid metal injection process is also coupled to the throat gas dynamics to achieve a more realistic simulation of the physics. The results from new nozzle designs, high temperature materials, and different gas flows are presented in this paper.

  15. Multi-bottle, no compressor, mean pressure control system for a Stirling engine

    SciTech Connect

    Corey, John A.

    1990-01-01

    The invention relates to an apparatus for mean pressure control of a Stirling engine without the need for a compressor. The invention includes a multi-tank system in which there is at least one high pressure level tank and one low pressure level tank wherein gas flows through a maximum pressure and supply line from the engine to the high pressure tank when a first valve is opened until the maximum pressure of the engine drops below that of the high pressure tank opening an inlet regulator to permit gas flow from the engine to the low pressure tank. When gas flows toward the engine it flows through the minimum pressure supply line 2 when a second valve is opened from the low pressure tank until the tank reaches the engine's minimum pressure level at which time the outlet regulator opens permitting gas to be supplied from the high pressure tank to the engine. Check valves between the two tanks prevent any backflow of gas from occurring.

  16. Independent Orbiter Assessment (IOA): Analysis of the atmospheric revitalization pressure control subsystem

    NASA Technical Reports Server (NTRS)

    Saiidi, M. J.; Duffy, R. E.; Mclaughlin, T. D.

    1986-01-01

    The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis/Critical Items List (FMEA/CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items. To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The independent analysis results corresponding to the Orbiter Atmospheric Revitalization and Pressure Control Subsystem (ARPCS) are documented. The ARPCS hardware was categorized into the following subdivisions: (1) Atmospheric Make-up and Control (including the Auxiliary Oxygen Assembly, Oxygen Assembly, and Nitrogen Assembly); and (2) Atmospheric Vent and Control (including the Positive Relief Vent Assembly, Negative Relief Vent Assembly, and Cabin Vent Assembly). The IOA analysis process utilized available ARPCS hardware drawings and schematics for defining hardware assemblies, components, and hardware items. Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode.

  17. Closed circuit MR compatible pulsatile pump system using a ventricular assist device and pressure control unit.

    PubMed

    Lorenz, R; Benk, C; Bock, J; Stalder, A F; Korvink, J G; Hennig, J; Markl, M

    2012-01-01

    The aim of this study was to evaluate the performance of a closed circuit MR compatible pneumatically driven pump system using a ventricular assist device as pulsatile flow pump for in vitro 3D flow simulation. Additionally, a pressure control unit was integrated into the flow circuit. The performance of the pump system and its test-retest reliability was evaluated using a stenosis phantom (60% lumen narrowing). Bland-Altman analysis revealed a good test-retest reliability (mean differences = -0.016 m/s, limits of agreement = ±0.047 m/s) for in vitro flow measurements. Furthermore, a rapid prototyping in vitro model of a normal thoracic aorta was integrated into the flow circuit for a direct comparison of flow characteristics with in vivo data in the same subject. The pneumatically driven ventricular assist device was attached to the ascending aorta of the in vitro model to simulate the beating left ventricle. In the descending part of the healthy aorta a flexible stenosis was integrated to model an aortic coarctation. In vivo and in vitro comparison showed significant (P = 0.002) correlations (r = 0.9) of mean velocities. The simulation of increasing coarctation grade led to expected changes in the flow patterns such as jet flow in the post-stenotic region and increased velocities. PMID:21630351

  18. Blood pressure control among patients with hypertension and newly diagnosed diabetes

    PubMed Central

    Choma, Neesha N.; Griffin, Marie R.; Kaltenbach, Lisa A.; Greevy, Robert A.; Roumie, Christianne L.

    2015-01-01

    Aims To determine the proportion of patients who achieved blood pressure (BP) control during the 2 years following new diabetes (DM) diagnosis. Methods A retrospective cohort of veterans ?18 years with hypertension who initiated a DM medication 2000 through 2007 in the Veterans Administration Mid-South Network was assembled. BP control at DM treatment initiation (baseline) was compared to BP control 6, 12, 18, and 24 months later. The VA and American Diabetes Association (ADA) definitions of control, ?140/90 and ?130/80 mm/Hg, respectively were primary and secondary outcomes. Results At baseline, 59.5% of 16182 patients had controlled BP according to the VA guideline (31.5% using ADA definition). Six months following initiation of DM treatment 65.7% had their blood pressure controlled (p<0.001). BP control was sustained but not further improved between 6 months and 2 years, with 66.5% controlled at 2 years following baseline. Higher initial systolic BP, black race, and hospitalization in the prior year were associated with higher likelihood of uncontrolled BP at 6 months; whereas, baseline cardiovascular disease, baseline dementia, and later year of cohort entry were associated with lower likelihood of uncontrolled BP. Conclusion We found an increase in BP control in the 6 months following initiation of DM treatment. However, overall BP control remained suboptimal, and with no further improvement over the next 18 months. PMID:22175281

  19. 46 CFR 38.20-10 - Ventilation-T/ALL.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Ventilation-T/ALL. 38.20-10 Section 38.20-10 Shipping... Ventilation § 38.20-10 Ventilation—T/ALL. (a) A power ventilation system shall be provided for compartments... equipped with power ventilation of the exhaust type having capacity sufficient to effect a complete...

  20. 46 CFR 38.20-10 - Ventilation-T/ALL.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Ventilation-T/ALL. 38.20-10 Section 38.20-10 Shipping... Ventilation § 38.20-10 Ventilation—T/ALL. (a) A power ventilation system shall be provided for compartments... equipped with power ventilation of the exhaust type having capacity sufficient to effect a complete...

  1. 46 CFR 38.20-10 - Ventilation-T/ALL.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Ventilation-T/ALL. 38.20-10 Section 38.20-10 Shipping... Ventilation § 38.20-10 Ventilation—T/ALL. (a) A power ventilation system shall be provided for compartments... equipped with power ventilation of the exhaust type having capacity sufficient to effect a complete...

  2. Particle deposition in ventilation ducts

    SciTech Connect

    Sippola, Mark R.

    2002-09-01

    Exposure to airborne particles is detrimental to human health and indoor exposures dominate total exposures for most people. The accidental or intentional release of aerosolized chemical and biological agents within or near a building can lead to exposures of building occupants to hazardous agents and costly building remediation. Particle deposition in heating, ventilation and air-conditioning (HVAC) systems may significantly influence exposures to particles indoors, diminish HVAC performance and lead to secondary pollutant release within buildings. This dissertation advances the understanding of particle behavior in HVAC systems and the fates of indoor particles by means of experiments and modeling. Laboratory experiments were conducted to quantify particle deposition rates in horizontal ventilation ducts using real HVAC materials. Particle deposition experiments were conducted in steel and internally insulated ducts at air speeds typically found in ventilation ducts, 2-9 m/s. Behaviors of monodisperse particles with diameters in the size range 1-16 {micro}m were investigated. Deposition rates were measured in straight ducts with a fully developed turbulent flow profile, straight ducts with a developing turbulent flow profile, in duct bends and at S-connector pieces located at duct junctions. In straight ducts with fully developed turbulence, experiments showed deposition rates to be highest at duct floors, intermediate at duct walls, and lowest at duct ceilings. Deposition rates to a given surface increased with an increase in particle size or air speed. Deposition was much higher in internally insulated ducts than in uninsulated steel ducts. In most cases, deposition in straight ducts with developing turbulence, in duct bends and at S-connectors at duct junctions was higher than in straight ducts with fully developed turbulence. Measured deposition rates were generally higher than predicted by published models. A model incorporating empirical equations based on the experimental measurements was applied to evaluate particle losses in supply and return duct runs. Model results suggest that duct losses are negligible for particle sizes less than 1 {micro}m and complete for particle sizes greater than 50 {micro}m. Deposition to insulated ducts, horizontal duct floors and bends are predicted to control losses in duct systems. When combined with models for HVAC filtration and deposition to indoor surfaces to predict the ultimate fates of particles within buildings, these results suggest that ventilation ducts play only a small role in determining indoor particle concentrations, especially when HVAC filtration is present. However, the measured and modeled particle deposition rates are expected to be important for ventilation system contamination.

  3. Cytokine and chemokine mRNA expression profiles in tracheobronchial lymph nodes from pigs singularly infected or coinfected with porcine circovirus type 2 (PCV2) and Mycoplasma hyopneumoniae (MHYO)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to determine cytokine and chemokine mRNA expression profiles in tracheobronchial lymph nodes from pigs singularly infected with porcine circovirus type 2 (PCV2), Mycoplasma hyopneumoniae (MHYO), or coinfected with both. Twenty-eight pigs were randomly assigned to one ...

  4. 46 CFR 111.103-1 - Power ventilation systems except machinery space ventilation systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Power ventilation systems except machinery space ventilation systems. 111.103-1 Section 111.103-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) ELECTRICAL ENGINEERING ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Remote Stopping Systems § 111.103-1 Power ventilation systems except...

  5. Constant Pressure-controlled Extrusion Method for the Preparation of Nano-sized Lipid Vesicles

    PubMed Central

    Yin, Hang

    2012-01-01

    Liposomes are artificially prepared vesicles consisting of natural and synthetic phospholipids that are widely used as a cell membrane mimicking platform to study protein-protein and protein-lipid interactions3, monitor drug delivery4,5, and encapsulation4. Phospholipids naturally create curved lipid bilayers, distinguishing itself from a micelle.6 Liposomes are traditionally classified by size and number of bilayers, i.e. large unilamellar vesicles (LUVs), small unilamellar vesicles (SUVs) and multilamellar vesicles (MLVs)7. In particular, the preparation of homogeneous liposomes of various sizes is important for studying membrane curvature that plays a vital role in cell signaling, endo- and exocytosis, membrane fusion, and protein trafficking8. Several groups analyze how proteins are used to modulate processes that involve membrane curvature and thus prepare liposomes of diameters <100 - 400 nm to study their behavior on cell functions3. Others focus on liposome-drug encapsulation, studying liposomes as vehicles to carry and deliver a drug of interest9. Drug encapsulation can be achieved as reported during liposome formation9. Our extrusion step should not affect the encapsulated drug for two reasons, i.e. (1) drug encapsulation should be achieved prior to this step and (2) liposomes should retain their natural biophysical stability, securely carrying the drug in the aqueous core. These research goals further suggest the need for an optimized method to design stable sub-micron lipid vesicles. Nonetheless, the current liposome preparation technologies (sonication10, freeze-and-thaw10, sedimentation) do not allow preparation of liposomes with highly curved surface (i.e. diameter <100 nm) with high consistency and efficiency10,5, which limits the biophysical studies of an emerging field of membrane curvature sensing. Herein, we present a robust preparation method for a variety of biologically relevant liposomes. Manual extrusion using gas-tight syringes and polycarbonate membranes10,5 is a common practice but heterogeneity is often observed when using pore sizes <100 nm due to due to variability of manual pressure applied. We employed a constant pressure-controlled extrusion apparatus to prepare synthetic liposomes whose diameters range between 30 and 400 nm. Dynamic light scattering (DLS)10, electron microscopy11 and nanoparticle tracking analysis (NTA)12 were used to quantify the liposome sizes as described in our protocol, with commercial polystyrene (PS) beads used as a calibration standard. A near linear correlation was observed between the employed pore sizes and the experimentally determined liposomes, indicating high fidelity of our pressure-controlled liposome preparation method. Further, we have shown that this lipid vesicle preparation method is generally applicable, independent of various liposome sizes. Lastly, we have also demonstrated in a time course study that these prepared liposomes were stable for up to 16 hours. A representative nano-sized liposome preparation protocol is demonstrated below. PMID:22760481

  6. Experimental analysis of pressure controlled atomization process (PCAP) coatings for replacement of hard chromium plating

    SciTech Connect

    Tierney, J.C.; Glovan, R.J.; Witt, S.J.; Verbael, D.J.

    1995-12-31

    A four-phase experimental design was utilized to evaluate the abrasive wear and corrosion protection characteristics of VERSAlloy 50 coatings applied to AISI 4130 steel sheet. The coatings were applied with the Pressure Controlled Atomization Process (PCAP), a new thermal spray process being developed for the United States Air Force to replace hard chromium plating. Phase 1 of the design consisted of an evaluation of deposit profiles that were sprayed at five different standoff distances. Profile measurements yielded standard deviations ({sigma}) of the plume at each of the spray distances. Phase 2 consisted of a completely randomized series of eight spray tests in which the track gap or distance between consecutive spray passes was varied by amounts of 0.5{sigma}, 1{sigma}, 2{sigma}, and 3{sigma}. The sprayed test coupons were then evaluated for corrosion protection, abrasive wear resistance, microhardness, and porosity. Results from Phase 2 were used to determine the best track gap or overlap for Phase 3 and Phase 4 testing. Phase 3 consisted of 22-run central composite design. The test coupons were evaluated the same as in Phase 2. Statistical analysis of Phase 3 data revealed that the optimal system operating parameters produced coatings that would either provide superior corrosion protection or resistance to abrasive wear. Phase 4 consisted of four spray tests to validate the results obtained in Phase 3. Phase 4 test coupons were again evaluated with the same analysis as in Phases 2 and 3. The validation tests indicated that PCAP system operating parameters could be controlled to produce VERSAlloy 50 coatings with superior corrosion protection or resistance to abrasive wear.

  7. Experimental Investigation on the Basic Law of Hydraulic Fracturing After Water Pressure Control Blasting

    NASA Astrophysics Data System (ADS)

    Huang, Bingxiang; Li, Pengfeng; Ma, Jian; Chen, Shuliang

    2014-07-01

    Because of the advantages of integrating water pressure blasting and hydraulic fracturing, the use of hydraulic fracturing after water pressure control blasting is a method that is used to fully transform the structure of a coal-rock mass by increasing the number and range of hydraulic cracks. An experiment to study hydraulic fracturing after water pressure blasting on cement mortar samples (300 × 300 × 300 mm3) was conducted using a large-sized true triaxial hydraulic fracturing experimental system. A traditional hydraulic fracturing experiment was also performed for comparison. The experimental results show that water pressure blasting produces many blasting cracks, and follow-up hydraulic fracturing forces blasting cracks to propagate further and to form numerous multidirectional hydraulic cracks. Four macroscopic main hydraulic cracks in total were noted along the borehole axial and radial directions on the sample surfaces. Axial and radial main failure planes induced by macroscopic main hydraulic cracks split the sample into three big parts. Meanwhile, numerous local hydraulic cracks were formed on the main failure planes, in different directions and of different types. Local hydraulic cracks are mainly of three types: local hydraulic crack bands, local branched hydraulic cracks, and axial layered cracks. Because local hydraulic cracks produce multiple local layered failure planes and lamellar ruptures inside the sample, the integrity of the sample decreases greatly. The formation and propagation process of many multidirectional hydraulic cracks is affected by a combination of water pressure blasting, water pressure of fracturing, and the stress field of the surrounding rock. To a certain degree, the stress field of surrounding rock guides the formation and propagation process of the blasting crack and the follow-up hydraulic crack. Following hydraulic fracturing that has been conducted after water pressure blasting, the integrity of the sample is found to be far lower than after traditional hydraulic fracturing; moreover, both the water injection volume and water injection pressure for hydraulic fracturing after water pressure blasting are much higher than they are for traditional hydraulic fracturing.

  8. A Multifunctional Frontloading Approach for Repeated Recycling of a Pressure-Controlled AFM Micropipette

    PubMed Central

    Roder, Phillip; Hille, Carsten

    2015-01-01

    Fluid force microscopy combines the positional accuracy and force sensitivity of an atomic force microscope (AFM) with nanofluidics via a microchanneled cantilever. However, adequate loading and cleaning procedures for such AFM micropipettes are required for various application situations. Here, a new frontloading procedure is described for an AFM micropipette functioning as a force- and pressure-controlled microscale liquid dispenser. This frontloading procedure seems especially attractive when using target substances featuring high costs or low available amounts. Here, the AFM micropipette could be filled from the tip side with liquid from a previously applied droplet with a volume of only a few ?L using a short low-pressure pulse. The liquid-loaded AFM micropipettes could be then applied for experiments in air or liquid environments. AFM micropipette frontloading was evaluated with the well-known organic fluorescent dye rhodamine 6G and the AlexaFluor647-labeled antibody goat anti-rat IgG as an example of a larger biological compound. After micropipette usage, specific cleaning procedures were tested. Furthermore, a storage method is described, at which the AFM micropipettes could be stored for a few hours up to several days without drying out or clogging of the microchannel. In summary, the rapid, versatile and cost-efficient frontloading and cleaning procedure for the repeated usage of a single AFM micropipette is beneficial for various application situations from specific surface modifications through to local manipulation of living cells, and provides a simplified and faster handling for already known experiments with fluid force microscopy. PMID:26636981

  9. Implementation of a Hybrid Controller for Ventilation Control Using Soft Computing

    SciTech Connect

    Craig G. Rieger; D. Subbaram Naidu

    2005-06-01

    Many industrial facilities utilize pressure control gradients to prevent migration of hazardous species from containment areas to occupied zones, often using Proportional-Integral-Derivative (PID) control systems. When operators rebalance the facility, variation from the desired gradients can occur and the operating conditions can change enough that the PID parameters are no longer adequate to maintain a stable system. As the goal of the ventilation control system is to optimize the pressure gradients and associated flows for the facility, Linear Quadratic Tracking (LQT) is a method that provides a time-based approach to guiding facility interactions. However, LQT methods are susceptible to modeling and measurement errors, and therefore the additional use of Soft Computing methods are proposed for implementation to account for these errors and nonlinearities.

  10. Maintenance Guide for Greenhouse Ventilation, Evaporative Cooling Heating Systems1

    E-print Network

    Hill, Jeffrey E.

    AE26 Maintenance Guide for Greenhouse Ventilation, Evaporative Cooling Heating Systems1 D. E and preventive maintenance procedures for ventilation, evaporative cooling and heating systems. Ventilation from evaporative cooling pads, high heating expenses, heavy condensation in winter, reduced life

  11. 46 CFR 153.316 - Special cargo pumproom ventilation rate.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 false Special cargo pumproom ventilation rate. 153.316 Section 153.316...Design and Equipment Cargo Handling Space Ventilation § 153.316 Special cargo pumproom ventilation rate. When Table 1 refers to...

  12. 46 CFR 111.103-3 - Machinery space ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 false Machinery space ventilation. 111.103-3 Section 111.103-3...Systems § 111.103-3 Machinery space ventilation. (a) Each machinery space ventilation system must have two controls to stop...

  13. 46 CFR 185.352 - Ventilation of gasoline machinery spaces.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Ventilation of gasoline machinery spaces...Operating Requirements § 185.352 Ventilation of gasoline machinery spaces. The mechanical exhaust for the ventilation of a gasoline machinery space,...

  14. 46 CFR 153.316 - Special cargo pumproom ventilation rate.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 false Special cargo pumproom ventilation rate. 153.316 Section 153.316...Design and Equipment Cargo Handling Space Ventilation § 153.316 Special cargo pumproom ventilation rate. When Table 1 refers to...

  15. 46 CFR 127.260 - Ventilation for accommodations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Ventilation for accommodations. 127.260 ...Construction and Arrangements § 127.260 Ventilation for accommodations. (a) Each...tons must be provided with a mechanical ventilation system unless the cognizant OCMI...

  16. 46 CFR 185.352 - Ventilation of gasoline machinery spaces.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false Ventilation of gasoline machinery spaces...Operating Requirements § 185.352 Ventilation of gasoline machinery spaces. The mechanical exhaust for the ventilation of a gasoline machinery space,...

  17. 24 CFR 3280.710 - Venting, ventilation and combustion air.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 2013-04-01 false Venting, ventilation and combustion air. 3280.710 ...Burning Systems § 3280.710 Venting, ventilation and combustion air. (a) The venting...instructions. Gravity or mechanical ventilation shall be installed within a...

  18. 21 CFR 888.4230 - Cement ventilation tube.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...2014-04-01 2014-04-01 false Cement ventilation tube. 888.4230 Section 888.4230...Surgical Devices § 888.4230 Cement ventilation tube. (a) Identification. A cement ventilation tube is a tube-like device...

  19. 46 CFR 153.316 - Special cargo pumproom ventilation rate.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 false Special cargo pumproom ventilation rate. 153.316 Section 153.316...Design and Equipment Cargo Handling Space Ventilation § 153.316 Special cargo pumproom ventilation rate. When Table 1 refers to...

  20. 21 CFR 888.4230 - Cement ventilation tube.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...2011-04-01 2011-04-01 false Cement ventilation tube. 888.4230 Section 888.4230...Surgical Devices § 888.4230 Cement ventilation tube. (a) Identification. A cement ventilation tube is a tube-like device...

  1. 24 CFR 3280.710 - Venting, ventilation and combustion air.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 2010-04-01 false Venting, ventilation and combustion air. 3280.710 ...Burning Systems § 3280.710 Venting, ventilation and combustion air. (a) The venting...instructions. Gravity or mechanical ventilation shall be installed within a...

  2. 33 CFR 183.630 - Standards for natural ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Standards for natural ventilation. 183.630 Section 183.630 Navigation...SAFETY BOATS AND ASSOCIATED EQUIPMENT Ventilation § 183.630 Standards for natural ventilation. (a) For the purpose of §...

  3. 49 CFR 192.187 - Vaults: Sealing, venting, and ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...false Vaults: Sealing, venting, and ventilation. 192.187 Section 192.187 ...187 Vaults: Sealing, venting, and ventilation. Each underground vault or closed...millimeters) in diameter; (2) The ventilation must be enough to minimize the...

  4. 46 CFR 154.1200 - Mechanical ventilation system: General.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false Mechanical ventilation system: General. 154.1200 Section...and Equipment Cargo Area: Mechanical Ventilation System § 154.1200 Mechanical ventilation system: General. (a) Each...

  5. 46 CFR 153.316 - Special cargo pumproom ventilation rate.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 false Special cargo pumproom ventilation rate. 153.316 Section 153.316...Design and Equipment Cargo Handling Space Ventilation § 153.316 Special cargo pumproom ventilation rate. When Table 1 refers to...

  6. 24 CFR 3280.103 - Light and ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 2010-04-01 false Light and ventilation. 3280.103 Section 3280.103...Considerations § 3280.103 Light and ventilation. (a) Lighting. Each habitable...whichever is greater. (b) Whole-house ventilation. Each manufactured home must be...

  7. 49 CFR 192.187 - Vaults: Sealing, venting, and ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...false Vaults: Sealing, venting, and ventilation. 192.187 Section 192.187 ...187 Vaults: Sealing, venting, and ventilation. Each underground vault or closed...millimeters) in diameter; (2) The ventilation must be enough to minimize the...

  8. 33 CFR 183.630 - Standards for natural ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Standards for natural ventilation. 183.630 Section 183.630 Navigation...SAFETY BOATS AND ASSOCIATED EQUIPMENT Ventilation § 183.630 Standards for natural ventilation. (a) For the purpose of §...

  9. 46 CFR 169.315 - Ventilation (other than machinery spaces).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Ventilation (other than machinery spaces). ...Arrangement Hull Structure § 169.315 Ventilation (other than machinery spaces). ...natural system will provide adequate ventilation in all ordinary weather...

  10. 46 CFR 127.260 - Ventilation for accommodations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Ventilation for accommodations. 127.260 ...Construction and Arrangements § 127.260 Ventilation for accommodations. (a) Each...tons must be provided with a mechanical ventilation system unless the cognizant OCMI...

  11. 46 CFR 111.103-3 - Machinery space ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 false Machinery space ventilation. 111.103-3 Section 111.103-3...Systems § 111.103-3 Machinery space ventilation. (a) Each machinery space ventilation system must have two controls to stop...

  12. 14 CFR 27.1187 - Ventilation and drainage.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Ventilation and drainage. 27.1187 Section...Powerplant Fire Protection § 27.1187 Ventilation and drainage. Each compartment...installation must have provision for ventilation and drainage of flammable fluids....

  13. 24 CFR 3280.103 - Light and ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 2012-04-01 false Light and ventilation. 3280.103 Section 3280.103...Considerations § 3280.103 Light and ventilation. (a) Lighting. Each habitable...whichever is greater. (b) Whole-house ventilation. Each manufactured home must be...

  14. 24 CFR 3280.710 - Venting, ventilation and combustion air.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 2012-04-01 false Venting, ventilation and combustion air. 3280.710 ...Burning Systems § 3280.710 Venting, ventilation and combustion air. (a) The venting...instructions. Gravity or mechanical ventilation shall be installed within a...

  15. 33 CFR 183.630 - Standards for natural ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false Standards for natural ventilation. 183.630 Section 183.630 Navigation...SAFETY BOATS AND ASSOCIATED EQUIPMENT Ventilation § 183.630 Standards for natural ventilation. (a) For the purpose of §...

  16. 46 CFR 127.260 - Ventilation for accommodations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Ventilation for accommodations. 127.260 ...Construction and Arrangements § 127.260 Ventilation for accommodations. (a) Each...tons must be provided with a mechanical ventilation system unless the cognizant OCMI...

  17. 21 CFR 888.4230 - Cement ventilation tube.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Cement ventilation tube. 888.4230 Section 888.4230...Surgical Devices § 888.4230 Cement ventilation tube. (a) Identification. A cement ventilation tube is a tube-like device...

  18. 46 CFR 111.103-3 - Machinery space ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 false Machinery space ventilation. 111.103-3 Section 111.103-3...Systems § 111.103-3 Machinery space ventilation. (a) Each machinery space ventilation system must have two controls to stop...

  19. 46 CFR 154.1200 - Mechanical ventilation system: General.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Mechanical ventilation system: General. 154.1200 Section...and Equipment Cargo Area: Mechanical Ventilation System § 154.1200 Mechanical ventilation system: General. (a) Each...

  20. 49 CFR 192.187 - Vaults: Sealing, venting, and ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...false Vaults: Sealing, venting, and ventilation. 192.187 Section 192.187 ...187 Vaults: Sealing, venting, and ventilation. Each underground vault or closed...millimeters) in diameter; (2) The ventilation must be enough to minimize the...

  1. 46 CFR 185.352 - Ventilation of gasoline machinery spaces.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Ventilation of gasoline machinery spaces...Operating Requirements § 185.352 Ventilation of gasoline machinery spaces. The mechanical exhaust for the ventilation of a gasoline machinery space,...

  2. 14 CFR 27.1187 - Ventilation and drainage.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Ventilation and drainage. 27.1187 Section...Powerplant Fire Protection § 27.1187 Ventilation and drainage. Each compartment...installation must have provision for ventilation and drainage of flammable fluids....

  3. 33 CFR 183.630 - Standards for natural ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Standards for natural ventilation. 183.630 Section 183.630 Navigation...SAFETY BOATS AND ASSOCIATED EQUIPMENT Ventilation § 183.630 Standards for natural ventilation. (a) For the purpose of §...

  4. 33 CFR 183.630 - Standards for natural ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Standards for natural ventilation. 183.630 Section 183.630 Navigation...SAFETY BOATS AND ASSOCIATED EQUIPMENT Ventilation § 183.630 Standards for natural ventilation. (a) For the purpose of §...

  5. 46 CFR 185.352 - Ventilation of gasoline machinery spaces.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Ventilation of gasoline machinery spaces...Operating Requirements § 185.352 Ventilation of gasoline machinery spaces. The mechanical exhaust for the ventilation of a gasoline machinery space,...

  6. 46 CFR 154.1200 - Mechanical ventilation system: General.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Mechanical ventilation system: General. 154.1200 Section...and Equipment Cargo Area: Mechanical Ventilation System § 154.1200 Mechanical ventilation system: General. (a) Each...

  7. 14 CFR 27.1187 - Ventilation and drainage.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Ventilation and drainage. 27.1187 Section...Powerplant Fire Protection § 27.1187 Ventilation and drainage. Each compartment...installation must have provision for ventilation and drainage of flammable fluids....

  8. 49 CFR 192.187 - Vaults: Sealing, venting, and ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...false Vaults: Sealing, venting, and ventilation. 192.187 Section 192.187 ...187 Vaults: Sealing, venting, and ventilation. Each underground vault or closed...millimeters) in diameter; (2) The ventilation must be enough to minimize the...

  9. 46 CFR 111.106-15 - Ventilation of hazardous locations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 2014-10-01 false Ventilation of hazardous locations. 111.106-15...Locations on OSVs § 111.106-15 Ventilation of hazardous locations. (a) The ventilation design principles must comply with...

  10. 24 CFR 3280.103 - Light and ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 2013-04-01 false Light and ventilation. 3280.103 Section 3280.103...Considerations § 3280.103 Light and ventilation. (a) Lighting. Each habitable...whichever is greater. (b) Whole-house ventilation. Each manufactured home must be...

  11. 24 CFR 3280.710 - Venting, ventilation and combustion air.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 2011-04-01 false Venting, ventilation and combustion air. 3280.710 ...Burning Systems § 3280.710 Venting, ventilation and combustion air. (a) The venting...instructions. Gravity or mechanical ventilation shall be installed within a...

  12. 46 CFR 111.103-3 - Machinery space ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 false Machinery space ventilation. 111.103-3 Section 111.103-3...Systems § 111.103-3 Machinery space ventilation. (a) Each machinery space ventilation system must have two controls to stop...

  13. 24 CFR 3280.710 - Venting, ventilation and combustion air.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 2014-04-01 false Venting, ventilation and combustion air. 3280.710 ...Burning Systems § 3280.710 Venting, ventilation and combustion air. (a) The venting...instructions. Gravity or mechanical ventilation shall be installed within a...

  14. 46 CFR 127.260 - Ventilation for accommodations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...2011-10-01 2011-10-01 false Ventilation for accommodations. 127.260 ...Construction and Arrangements § 127.260 Ventilation for accommodations. (a) Each...tons must be provided with a mechanical ventilation system unless the cognizant OCMI...

  15. 49 CFR 192.187 - Vaults: Sealing, venting, and ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...false Vaults: Sealing, venting, and ventilation. 192.187 Section 192.187 ...187 Vaults: Sealing, venting, and ventilation. Each underground vault or closed...millimeters) in diameter; (2) The ventilation must be enough to minimize the...

  16. 46 CFR 153.316 - Special cargo pumproom ventilation rate.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 false Special cargo pumproom ventilation rate. 153.316 Section 153.316...Design and Equipment Cargo Handling Space Ventilation § 153.316 Special cargo pumproom ventilation rate. When Table 1 refers to...

  17. 46 CFR 169.315 - Ventilation (other than machinery spaces).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...2010-10-01 2010-10-01 false Ventilation (other than machinery spaces). ...Arrangement Hull Structure § 169.315 Ventilation (other than machinery spaces). ...natural system will provide adequate ventilation in all ordinary weather...

  18. 46 CFR 154.1200 - Mechanical ventilation system: General.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 2012-10-01 false Mechanical ventilation system: General. 154.1200 Section...and Equipment Cargo Area: Mechanical Ventilation System § 154.1200 Mechanical ventilation system: General. (a) Each...

  19. 46 CFR 185.352 - Ventilation of gasoline machinery spaces.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Ventilation of gasoline machinery spaces...Operating Requirements § 185.352 Ventilation of gasoline machinery spaces. The mechanical exhaust for the ventilation of a gasoline machinery space,...

  20. 46 CFR 111.103-3 - Machinery space ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 false Machinery space ventilation. 111.103-3 Section 111.103-3...Systems § 111.103-3 Machinery space ventilation. (a) Each machinery space ventilation system must have two controls to stop...

  1. 24 CFR 3280.103 - Light and ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 2011-04-01 false Light and ventilation. 3280.103 Section 3280.103...Considerations § 3280.103 Light and ventilation. (a) Lighting. Each habitable...whichever is greater. (b) Whole-house ventilation. Each manufactured home must be...

  2. 46 CFR 127.260 - Ventilation for accommodations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 2013-10-01 false Ventilation for accommodations. 127.260 ...Construction and Arrangements § 127.260 Ventilation for accommodations. (a) Each...tons must be provided with a mechanical ventilation system unless the cognizant OCMI...

  3. 24 CFR 3280.103 - Light and ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 2014-04-01 false Light and ventilation. 3280.103 Section 3280.103...Considerations § 3280.103 Light and ventilation. (a) Lighting. Each habitable...whichever is greater. (b) Whole-house ventilation. Each manufactured home must be...

  4. 21 CFR 888.4230 - Cement ventilation tube.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...2012-04-01 2012-04-01 false Cement ventilation tube. 888.4230 Section 888.4230...Surgical Devices § 888.4230 Cement ventilation tube. (a) Identification. A cement ventilation tube is a tube-like device...

  5. 21 CFR 888.4230 - Cement ventilation tube.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...2013-04-01 2013-04-01 false Cement ventilation tube. 888.4230 Section 888.4230...Surgical Devices § 888.4230 Cement ventilation tube. (a) Identification. A cement ventilation tube is a tube-like device...

  6. Healthcare Technology Management (HTM) of mechanical ventilators by clinical engineers.

    PubMed

    Yoshioka, Jun; Nakane, Masaki; Kawamae, Kaneyuki

    2014-01-01

    Mechanical ventilator failures expose patients to unacceptable risks, and maintaining mechanical ventilator safety is an important issue. We examined the usefulness of maintaining mechanical ventilators by clinical engineers (CEs) using a specialized calibrator. These evaluations and the ability to make in-house repairs proved useful for obviating the need to rent ventilators which, in turn, might prove faulty themselves. The CEs' involvement in maintaining mechanical ventilators is desirable, ensures prompt service, and, most importantly, enhances safe management of mechanical ventilators. PMID:25520839

  7. History of Mechanical Ventilation. From Vesalius to Ventilator-induced Lung Injury.

    PubMed

    Slutsky, Arthur S

    2015-05-15

    Mechanical ventilation is a life-saving therapy that catalyzed the development of modern intensive care units. The origins of modern mechanical ventilation can be traced back about five centuries to the seminal work of Andreas Vesalius. This article is a short history of mechanical ventilation, tracing its origins over the centuries to the present day. One of the great advances in ventilatory support over the past few decades has been the development of lung-protective ventilatory strategies, based on our understanding of the iatrogenic consequences of mechanical ventilation such as ventilator-induced lung injury. These strategies have markedly improved clinical outcomes in patients with respiratory failure. PMID:25844759

  8. Mechanical ventilation: introduction for the pharmacy practitioner.

    PubMed

    Cawley, Michael J

    2011-02-01

    Mechanical ventilation is a common therapeutic modality required for the management of patients unable to maintain adequate intrinsic ventilation and oxygenation. Mechanical ventilators can be found within various hospital and nonhospital environments (ie, nursing homes, skilled nursing facilities, and patient's home residence), but these devices generally require the skill of a multidisciplinary health care team to optimize therapeutic outcomes. Unfortunately, pharmacists have been excluded in the discussion of mechanical ventilation since this therapeutic modality may be perceived as irrelevant to drug utilization and the usual scope of practice of a hospital pharmacist. However, the pharmacist provides a crucial role as a member of the multidisciplinary team in the management of the mechanically ventilated patient by verifying accuracy of prescribed medications, providing recommendations of alternative drug selections, monitoring for drug and disease interactions, assisting in the development of institutional weaning protocols, and providing quality assessment of drug utilization. Pharmacists may be intimidated by the introduction of advanced ventilator microprocessor technology, but understanding and integrating ventilator management with the pharmacotherapeutic needs of the patient will ultimately help the pharmacist be a better qualified and respected practitioner. The goal of this article is to assist the pharmacy practitioner with a better understanding of mechanical ventilation and to apply this information to improve delivery of pharmaceutical care. PMID:21507870

  9. 29 CFR 1910.94 - Ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 5 2012-07-01 2012-07-01 false Ventilation. 1910.94 Section 1910.94 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR OCCUPATIONAL SAFETY AND HEALTH STANDARDS Occupational Health and Environmental Control § 1910.94 Ventilation. (a) Abrasive blasting—(1)...

  10. 46 CFR 72.05-50 - Ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 3 2011-10-01 2011-10-01 false Ventilation. 72.05-50 Section 72.05-50 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS CONSTRUCTION AND ARRANGEMENT Structural Fire Protection § 72.05-50 Ventilation. (a) Where the term duct is used in this section, it shall include trunks, plenums, and any other...

  11. Commissioning Ventilated Containment Systems in the Laboratory

    SciTech Connect

    Not Available

    2008-08-01

    This Best Practices Guide focuses on the specialized approaches required for ventilated containment systems, understood to be all components that drive and control ventilated enclosures and local exhaust systems within the laboratory. Geared toward architects, engineers, and facility managers, this guide provides information about technologies and practices to use in designing, constructing, and operating operating safe, sustainable, high-performance laboratories.

  12. Infiltration in ASHRAE's Residential Ventilation Standards

    SciTech Connect

    Sherman, Max

    2008-10-01

    The purpose of ventilation is to dilute or remove indoor contaminants that an occupant could be exposed to. It can be provided by mechanical or natural means. ASHRAE Standards including standards 62, 119, and 136 have all considered the contribution of infiltration in various ways, using methods and data from 20 years ago. The vast majority of homes in the United States and indeed the world are ventilated through natural means such as infiltration caused by air leakage. Newer homes in the western world are tight and require mechanical ventilation. As we seek to provide acceptable indoor air quality at minimum energy cost, it is important to neither over-ventilate norunder-ventilate. Thus, it becomes critically important to correctly evaluate the contribution infiltration makes to both energy consumption and equivalent ventilation. ASHRAE Standard 62.2 specifies how much mechanical ventilation is considered necessary to provide acceptable indoor air quality, but that standard is weak on how infiltration can contribute towards meeting the total requirement. In the past ASHRAE Standard 136 was used to do this, but new theoretical approaches and expanded weather data have made that standard out of date. This article will describe how to properly treat infiltration as an equivalent ventilation approach and then use new data and these new approaches to demonstrate how these calculations might be done both in general and to update Standard 136.

  13. 14 CFR 252.9 - Ventilation systems.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Ventilation systems. 252.9 Section 252.9 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS SMOKING ABOARD AIRCRAFT § 252.9 Ventilation systems. Air carriers shall prohibit smoking...

  14. 14 CFR 252.9 - Ventilation systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Ventilation systems. 252.9 Section 252.9 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS SMOKING ABOARD AIRCRAFT § 252.9 Ventilation systems. Air carriers shall prohibit smoking...

  15. 14 CFR 252.9 - Ventilation systems.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Ventilation systems. 252.9 Section 252.9 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS SMOKING ABOARD AIRCRAFT § 252.9 Ventilation systems. Air carriers shall prohibit smoking...

  16. 14 CFR 252.9 - Ventilation systems.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Ventilation systems. 252.9 Section 252.9 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS SMOKING ABOARD AIRCRAFT § 252.9 Ventilation systems. Air carriers shall prohibit smoking...

  17. 14 CFR 252.9 - Ventilation systems.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Ventilation systems. 252.9 Section 252.9 Aeronautics and Space OFFICE OF THE SECRETARY, DEPARTMENT OF TRANSPORTATION (AVIATION PROCEEDINGS) ECONOMIC REGULATIONS SMOKING ABOARD AIRCRAFT § 252.9 Ventilation systems. Air carriers shall prohibit smoking...

  18. 46 CFR 194.15-5 - Ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Ventilation. 194.15-5 Section 194.15-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OCEANOGRAPHIC RESEARCH VESSELS HANDLING, USE, AND CONTROL OF EXPLOSIVES AND OTHER HAZARDOUS MATERIALS Chemistry Laboratory and Scientific Laboratory § 194.15-5 Ventilation. (a) Operations, reactions...

  19. Preoperational test report, primary ventilation system

    SciTech Connect

    Clifton, F.T.

    1997-11-04

    This represents a preoperational test report for Primary Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides vapor space filtered venting of tanks AY101, AY102, AZ101, AZ102. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  20. Evaluation of anticipatory signal to steam generator pressure control program for 700 MWe Indian pressurized heavy water reactor

    SciTech Connect

    Pahari, S.; Hajela, S.; Rammohan, H. P.; Malhotra, P. K.; Ghadge, S. G.

    2012-07-01

    700 MWe Indian Pressurized Heavy Water Reactor (IPHWR) is horizontal channel type reactor with partial boiling at channel outlet. Due to boiling, it has a large volume of vapor present in the primary loops. It has two primary loops connected with the help of pressurizer surge line. The pressurizer has a large capacity and is partly filled by liquid and partly by vapor. Large vapor volume improves compressibility of the system. During turbine trip or load rejection, pressure builds up in Steam Generator (SG). This leads to pressurization of Primary Heat Transport System (PHTS). To control pressurization of SG and PHTS, around 70% of the steam generated in SG is dumped into the condenser by opening Condenser Steam Dump Valves (CSDVs) and rest of the steam is released to the atmosphere by opening Atmospheric Steam Discharge Valves (ASDVs) immediately after sensing the event. This is accomplished by adding anticipatory signal to the output of SG pressure controller. Anticipatory signal is proportional to the thermal power of reactor and the proportionality constant is set so that SG pressure controller's output jacks up to ASDV opening range when operating at 100% FP. To simulate this behavior for 700 MWe IPHWR, Primary and secondary heat transport system is modeled. SG pressure control and other process control program have also been modeled to capture overall plant dynamics. Analysis has been carried out with 3-D neutron kinetics coupled thermal hydraulic computer code ATMIKA.T to evaluate the effect of the anticipatory signal on PHT pressure and over all plant dynamics during turbine trip in 700 MWe IPHWR. This paper brings out the results of the analysis with and without considering anticipatory signal in SG pressure control program during turbine trip. (authors)

  1. Dynamic Behaviour of Ventilated Hydrofoils.

    NASA Astrophysics Data System (ADS)

    Kjeldsen, Morten; Arndt, Roger; Wosnik, Martin

    2006-11-01

    In certain types of pumping applications oscillations are induced by operation with liquids containing a free gas load. In order to understand the physics of this process, a series of tests with a ventilated A 2D NACA 0015 hydrofoil were performed in the water tunnel at the St. Anthony Falls Laboratory of the University of Minnesota. The special bubble removal feature of the water tunnel allowed continuous ventilation without experiencing visible bubbles upstream the hydrofoil. These studies build on previous work on cavitation-induced oscillations. Gas injection studies were made over a range of gas flow rates and test section pressure. The results clearly show that lift oscillations increase in intensity when the gas load is increased. The point of maximum unsteadiness is also associated the rapid decline of the foil performance as measured as average lift. Further increase of the gas injection load gives a steady behaviour with almost no lift. These experiments are compared with traditional cavitation experiments. The similarities between gas injection- and cavitation induced unsteadiness on the hydrofoil are many, but the amplitude of lift oscillations found on the foil with gas injection corresponds to about 50% of that found for cavitating hydrofoils. The fact that the oscillations are periodic leads to the consideration of both passive and active control.

  2. An intelligent control system for ventilators.

    PubMed

    Wang, C S; Shaw, D; Jih, K S

    1998-10-01

    This study reports on a ventilator system that consists of several intelligent modules for controlling ventilator operation. These modules are software programs in two controllers. One controller is a personal computer used for diagnoses, determining settings and checking the effects of settings. The other controller is a single-chip microprocessor in a ventilator that controls the ventilator's settings in accordance with the computer settings. After setting up the system, an artificial lung model simulating a patient's lung is used to test the system. The result of test run indicated that it always responds to a patient's lung condition in a stable manner. Thus, the proposed system with its intelligent modules may assist clinicians in caring for patients and managing ventilator operation. PMID:9832029

  3. Mine ventilation and air conditioning. 3. edition

    SciTech Connect

    Hartman, H.L.; Mutmansky, J.M.; Ramani, R.V.; Wang, Y.J.

    1998-12-31

    This revised edition presents an engineering design approach to ventilation and air conditioning as part of the comprehensive environmental control of the mine atmosphere. It provides an in-depth look, for practitioners who design and operate mines, into the health and safety aspects of environmental conditions in the underground workplace. The contents include: Environmental control of the mine atmosphere; Properties and behavior of air; Mine air-quality control; Mine gases; Dusts and other mine aerosols; Mine ventilation; Airflow through mine openings and ducts; Mine ventilation circuits and networks; Natural ventilation; Fan application to mines; Auxiliary ventilation and controlled recirculation; Economics of airflow; Control of mine fires and explosions; Mine air conditioning; Heat sources and effect in mines; Mine air conditioning systems; Appendices; References; Answers to selected problems; and Index.

  4. Neonatal mechanical ventilation: Indications and outcome

    PubMed Central

    Iqbal, Qazi; Younus, Mir M.; Ahmed, Asif; Ahmad, Ikhlas; Iqbal, Javed; Charoo, Bashir A.; Ali, S Wajid

    2015-01-01

    Background and Aims: Decreasing mortality in sick and ventilated neonates is an endeavor of all neonatologists. To reduce the high mortality in this group of neonates, identification of risk factors is important. This study was undertaken to find out the indications of ventilation and complications in ventilated neonates and also study possible predictors of outcome. Subjects: Age <1-month; mechanically ventilated; not having suspected metabolic disorders or congenital anomalies; excluding postoperative patients. Methods: Neonates consecutively put on mechanical ventilation during the study period (October 2011 to November 2013) enrolled. Primary disease of the neonates along with complications present listed. Clinical and laboratory parameters analyzed to find the predictors of mortality. Results: Total 300 neonates were ventilated. 52% were male. Mean age, weight, and gestational age were 21 ± 62 h, 2320 ± 846.2 g, and 35.2 ± 4.9 weeks, respectively. 130 (43%) neonates died. Respiratory distress syndrome (RDS) (31.1%), sepsis (22.7%), and birth asphyxia (18%) were the most common indications for ventilation. Mortality in ventilated patients with sepsis, pneumonia, RDS or birth asphyxia was 64.7%, 60%, 44.6%, and 33.3%, respectively. Weight <2500 g, gestation <34 weeks, initial pH <7.1, presence of sepsis, apnea, shock, pulmonary hemorrhage, hypoglycemia, neutropenia, and thrombocytopenia were significantly associated with mortality (P < 0.05). Resuscitation at birth, seizures, intra ventricular hemorrhage, pneumothorax, ventilator-associated pneumonia, PO2, or PCO2 did not have a significant association with mortality. On logistic regression, gestation <34 weeks, initial pH <7.1, pulmonary hemorrhage, or shock were independently significant predictors of mortality. Conclusions: Weight <2500 g, gestation <34 weeks, initial arterial pH <7.1, shock, pulmonary hemorrhage, apnea, hypoglycemia, neutropenia, and thrombocytopenia were significant predictors of mortality in ventilated neonates. PMID:26430338

  5. A new system for understanding modes of mechanical ventilation.

    PubMed

    Chatburn, R L; Primiano, F P

    2001-06-01

    Numerous ventilation modes and ventilation options have become available as new mechanical ventilators have reached the market. Ventilator manufacturers have no standardized terminology for ventilator modes and ventilation options, and ventilator operator's manuals do not help the clinician compare the modes of ventilators from different manufacturers. This article proposes a standardized system for classifying ventilation modes, based on general engineering principles and a small set of explicit definitions. Though there may be resistance by ventilator manufacturers to a standardized system of ventilation terminology, clinicians and health care equipment purchasers should adopt such a system in the interest of clear communication--the lack of which prevents clinicians from fully understanding the therapies they administer and could compromise the quality of patient care. PMID:11353550

  6. [Recommendations for invasive home mechanical ventilation].

    PubMed

    Randerath, W J; Kamps, N; Brambring, J; Gerhard, F; Lorenz, J; Rudolf, F; Rosseau, S; Scheumann, A; Vollmer, V; Windisch, W

    2011-02-01

    Due to chronic respiratory failure, a proportion of patients require long-term home ventilation therapy. The treating doctors, nurses and therapists, as well as employees of the health insurance provider, all require specialized knowledge in order to establish and monitor home ventilation. The following document represents a consensus formed by the participating specialist societies, the health insurers and their medical advisory services. The recommendations for accomplishing home mechanical ventilation are based on the "S2 Guidelines for Non-Invasive and Invasive Mechanical Ventilation for Treatment of Chronic Respiratory Failure", and provide advice about the necessary qualifications of medical and nursing practitioners working in specialised ventilation centres or in the home setting. Management of transfer, which comprises the medical, technical and organisational requirements for releasing the patient from hospital care, is of paramount importance. In outpatient care, the requirements for the recruitment of resources, monitoring of procedures, adjustment of ventilation, and frequency of check-ups are each addressed. The recommendations are supplemented by appendices which include patient transfer forms, checklists for the supply of basic resources for home ventilation, as well as a template for the letter of discharge from hospital. PMID:21294061

  7. Evidence-based ventilator weaning and discontinuation.

    PubMed

    MacIntyre, Neil R

    2004-07-01

    Ventilator management of a patient who is recovering from acute respiratory failure must balance competing objectives. Discontinuing mechanical ventilation and removing the artificial airway as soon as possible reduces the risk of ventilator-induced lung injury, nosocomial pneumonia, airway trauma from the endotracheal tube, and unnecessary sedation, but premature ventilator-discontinuation or extubation can cause ventilatory muscle fatigue, gas exchange failure, and loss of airway protection. In 1999 the McMaster University Outcomes Research Unit conducted a comprehensive evidence-based review of the literature on ventilator-discontinuation. Using that literature review, the American College of Chest Physicians, the Society of Critical Care Medicine, and the American Association for Respiratory Care created evidence-based guidelines, which include the following principles: 1. Frequent assessment is required to determine whether ventilatory support and the artificial airway are still needed. 2. Patients who continue to require support should be continually re-evaluated to assure that all factors contributing to ventilator dependence are addressed. 3. With patients who continue to require support, the support strategy should maximize patient comfort and provide muscle unloading. 4. Patients who require prolonged ventilatory support beyond the intensive care unit should go to specialized facilities that can provide more gradual support reduction strategies. 5. Ventilator-discontinuation and weaning protocols can be effectively carried out by nonphysician clinicians. PMID:15222913

  8. Optimization on Emergency Longitudinal Ventilation Design

    NASA Astrophysics Data System (ADS)

    Se, Camby M. K.; Yuen, Richard K. K.; Cheung, Sherman C. P.; Tu, Jiyuan

    2010-05-01

    Emergency ventilation design in longitudinally ventilated vehicular tunnels is vital to provide safe egress route for tunnel user under fire situations. In this study, the influences of the location of active fan groups on the upstream velocity are investigated using Computational Fluid Dynamics (CFD) techniques. The numeric model was firstly validated again the experimental data from Memorial Tunnel Fire Ventilation Test Program (MTFVTP). Based on the validated model, parametric studies were then preformed attempting to establish a semi-empirical correlation between the location of fan groups and the upstream velocity. In the presence of solid fire, it was found that the buoyant force by the fire source and inertial force by the fans interact with each other and resulted in a "leveling-off" characteristic when the inertial force is no longer dominating. Such interaction re-distributed the ventilation flow direction and sequentially reduces the magnitude of the upstream velocity. In other word, the industrial practice of activating furthest fan group may not be able to prevent the backlayering as a consequence of solid fires. Fans closer to the fire source are recommended to be activated for preventing the hazard of backlayering. Furthermore, through the parametric study, location of ventilation fans is found to have significant effect on the upstream velocity. Such finding suggests that other geometrical parameters could also impose adverse effects to the ventilation system. Existing empirical equation could be insufficient to cover all possible ventilation design scenarios.

  9. Quantification of ventilation characteristics of a helmet.

    PubMed

    Van Brecht, A; Nuyttens, D; Aerts, J M; Quanten, S; De Bruyne, G; Berckmans, D

    2008-05-01

    Despite the augmented safety offered by wearing a cyclist crash helmet, many cyclists still refuse to wear one because of the thermal discomfort that comes along with wearing it. In this paper, a method is described that quantifies the ventilation characteristics of a helmet using tracer gas experiments. A Data-Based Mechanistic model was applied to provide a physically meaningful description of the dominant internal dynamics of mass transfer in the imperfectly mixed fluid under the helmet. By using a physical mass balance, the local ventilation efficiency could be described by using a single input-single output system. Using this approach, ventilation efficiency ranging from 0.06 volume refreshments per second (s(-1)) at the side of the helmet to 0.22s(-1) at the rear ventilation opening were found on the investigated helmet. The zones at the side were poorly ventilated. The influence of the angle of inclination on ventilation efficiency was dependent on the position between head and helmet. General comfort of the helmet can be improved by increasing the ventilation efficiency of fresh air at the problem zones. PMID:17959135

  10. Weaning from prolonged mechanical ventilation.

    PubMed

    Nevins, M L; Epstein, S K

    2001-03-01

    The development of weaning failure and need for PMV is multifactorial in origin, involving disorders of pulmonary mechanics and complications associated with critical illness. The underlying disease process is clearly important when discussing mechanisms of ventilator dependence; interventions therefore must be tailored to individual patients. Unfortunately, the main conclusion that can be drawn from the sum of the studies investigating patients on PMV to date is that an evidence-based approach to weaning is not possible and more research needs to be done. New studies need to incorporate severity-of-illness scores and an assessment of principal and comorbid conditions to allow for comparison of the findings from different centers. The best approach to a patient requiring PMV after exclusion of easily treatable conditions is not known. The literature regarding both acute and chronic cases suggests that a systematic approach to weaning involving the participation of multiple caregivers, including nurses, physicians, and respiratory, physical, and speech therapists facilitates liberation from MV. Although a gradual decrement in ventilator support would seem prudent, Scheinhorn et al have begun to identify a subpopulation of patients who can tolerate an acceleration of the weaning process. Given the known complications associated with MV, it is crucial that further research be performed to identify patients as soon as they are capable of breathing spontaneously. The literature demonstrates through multiple studies that satisfactory patient outcomes are attainable and can be achieved at LTAC facilities in a more cost-effective manner than in an ICU setting. The trend toward the concentration of patients into specialized regional weaning centers should facilitate the research process and continue to improve outcomes in this population. PMID:11315451

  11. 46 CFR 38.20-10 - Ventilation-T/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Ventilation-T/ALL. 38.20-10 Section 38.20-10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS LIQUEFIED FLAMMABLE GASES Venting and Ventilation § 38.20-10 Ventilation—T/ALL. (a) A power ventilation system shall be provided for...

  12. 46 CFR 154.1200 - Mechanical ventilation system: General.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Mechanical ventilation system: General. 154.1200 Section... Equipment Cargo Area: Mechanical Ventilation System § 154.1200 Mechanical ventilation system: General. (a... cargo handling equipment must have a fixed, exhaust-type mechanical ventilation system. (b)...

  13. 46 CFR 154.1200 - Mechanical ventilation system: General.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Mechanical ventilation system: General. 154.1200 Section... Equipment Cargo Area: Mechanical Ventilation System § 154.1200 Mechanical ventilation system: General. (a... cargo handling equipment must have a fixed, exhaust-type mechanical ventilation system. (b)...

  14. 46 CFR 154.1205 - Mechanical ventilation system: Standards.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Mechanical ventilation system: Standards. 154.1205... Equipment Cargo Area: Mechanical Ventilation System § 154.1205 Mechanical ventilation system: Standards. (a) Each exhaust type mechanical ventilation system required under § 154.1200 (a) must have ducts...

  15. 46 CFR 154.1205 - Mechanical ventilation system: Standards.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Mechanical ventilation system: Standards. 154.1205... Equipment Cargo Area: Mechanical Ventilation System § 154.1205 Mechanical ventilation system: Standards. (a) Each exhaust type mechanical ventilation system required under § 154.1200 (a) must have ducts...

  16. 46 CFR 108.181 - Ventilation for enclosed spaces.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Ventilation for enclosed spaces. 108.181 Section 108.181... AND EQUIPMENT Construction and Arrangement Ventilation § 108.181 Ventilation for enclosed spaces. (a) Each enclosed space must be vented or ventilated. (b) There must be a means to close each vent...

  17. 46 CFR 111.103-3 - Machinery space ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Machinery space ventilation. 111.103-3 Section 111.103-3...-GENERAL REQUIREMENTS Remote Stopping Systems § 111.103-3 Machinery space ventilation. (a) Each machinery space ventilation system must have two controls to stop the ventilation, one of which may be the...

  18. 46 CFR 108.181 - Ventilation for enclosed spaces.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Ventilation for enclosed spaces. 108.181 Section 108.181... AND EQUIPMENT Construction and Arrangement Ventilation § 108.181 Ventilation for enclosed spaces. (a) Each enclosed space must be vented or ventilated. (b) There must be a means to close each vent...

  19. 46 CFR 111.103-3 - Machinery space ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Machinery space ventilation. 111.103-3 Section 111.103-3...-GENERAL REQUIREMENTS Remote Stopping Systems § 111.103-3 Machinery space ventilation. (a) Each machinery space ventilation system must have two controls to stop the ventilation, one of which may be the...

  20. 46 CFR 72.15-15 - Ventilation for closed spaces.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 3 2014-10-01 2014-10-01 false Ventilation for closed spaces. 72.15-15 Section 72.15-15... ARRANGEMENT Ventilation § 72.15-15 Ventilation for closed spaces. (a) All enclosed spaces within the vessel... spaces and for closing all doorways, ventilators and annular spaces around funnels and other openings...

  1. 46 CFR 72.15-15 - Ventilation for closed spaces.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 3 2013-10-01 2013-10-01 false Ventilation for closed spaces. 72.15-15 Section 72.15-15... ARRANGEMENT Ventilation § 72.15-15 Ventilation for closed spaces. (a) All enclosed spaces within the vessel... spaces and for closing all doorways, ventilators and annular spaces around funnels and other openings...

  2. 46 CFR 111.103-3 - Machinery space ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Machinery space ventilation. 111.103-3 Section 111.103-3...-GENERAL REQUIREMENTS Remote Stopping Systems § 111.103-3 Machinery space ventilation. (a) Each machinery space ventilation system must have two controls to stop the ventilation, one of which may be the...

  3. 46 CFR 72.15-15 - Ventilation for closed spaces.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 3 2012-10-01 2012-10-01 false Ventilation for closed spaces. 72.15-15 Section 72.15-15... ARRANGEMENT Ventilation § 72.15-15 Ventilation for closed spaces. (a) All enclosed spaces within the vessel... spaces and for closing all doorways, ventilators and annular spaces around funnels and other openings...

  4. 46 CFR 108.181 - Ventilation for enclosed spaces.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Ventilation for enclosed spaces. 108.181 Section 108.181... AND EQUIPMENT Construction and Arrangement Ventilation § 108.181 Ventilation for enclosed spaces. (a) Each enclosed space must be vented or ventilated. (b) There must be a means to close each vent...

  5. THE MECHANICS OF LUNG TISSUE UNDER HIGH-FREQUENCY VENTILATION

    E-print Network

    THE MECHANICS OF LUNG TISSUE UNDER HIGH-FREQUENCY VENTILATION MARKUS R. OWEN AND MARK A. LEWIS Abstract. High frequency ventilation is a radical departure from conventional lung ventilation question concerns ventilator induced damage to the lung tissue, and a clear protocol for the most effective

  6. 30 CFR 77.1911 - Ventilation of slopes and shafts.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Ventilation of slopes and shafts. 77.1911...Slope and Shaft Sinking § 77.1911 Ventilation of slopes and shafts. (a) All...shafts shall be ventilated by mechanical ventilation equipment during development....

  7. 30 CFR 77.1911 - Ventilation of slopes and shafts.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Ventilation of slopes and shafts. 77.1911...Slope and Shaft Sinking § 77.1911 Ventilation of slopes and shafts. (a) All...shafts shall be ventilated by mechanical ventilation equipment during development....

  8. 46 CFR 38.20-10 - Ventilation-T/ALL.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Ventilation-T/ALL. 38.20-10 Section 38.20-10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS LIQUEFIED FLAMMABLE GASES Venting and Ventilation § 38.20-10 Ventilation—T/ALL. (a) A power ventilation system shall be provided for compartments containing pumps, compressors, pipes,...

  9. 46 CFR 72.15-15 - Ventilation for closed spaces.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 3 2011-10-01 2011-10-01 false Ventilation for closed spaces. 72.15-15 Section 72.15-15... ARRANGEMENT Ventilation § 72.15-15 Ventilation for closed spaces. (a) All enclosed spaces within the vessel... spaces and for closing all doorways, ventilators and annular spaces around funnels and other openings...

  10. 46 CFR 111.103-3 - Machinery space ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Machinery space ventilation. 111.103-3 Section 111.103-3...-GENERAL REQUIREMENTS Remote Stopping Systems § 111.103-3 Machinery space ventilation. (a) Each machinery space ventilation system must have two controls to stop the ventilation, one of which may be the...

  11. 46 CFR 108.181 - Ventilation for enclosed spaces.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Ventilation for enclosed spaces. 108.181 Section 108.181... AND EQUIPMENT Construction and Arrangement Ventilation § 108.181 Ventilation for enclosed spaces. (a) Each enclosed space must be vented or ventilated. (b) There must be a means to close each vent...

  12. 46 CFR 72.15-15 - Ventilation for closed spaces.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Ventilation for closed spaces. 72.15-15 Section 72.15-15... ARRANGEMENT Ventilation § 72.15-15 Ventilation for closed spaces. (a) All enclosed spaces within the vessel... spaces and for closing all doorways, ventilators and annular spaces around funnels and other openings...

  13. 46 CFR 108.181 - Ventilation for enclosed spaces.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Ventilation for enclosed spaces. 108.181 Section 108.181... AND EQUIPMENT Construction and Arrangement Ventilation § 108.181 Ventilation for enclosed spaces. (a) Each enclosed space must be vented or ventilated. (b) There must be a means to close each vent...

  14. 46 CFR 111.103-3 - Machinery space ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Machinery space ventilation. 111.103-3 Section 111.103-3...-GENERAL REQUIREMENTS Remote Stopping Systems § 111.103-3 Machinery space ventilation. (a) Each machinery space ventilation system must have two controls to stop the ventilation, one of which may be the...

  15. Gastric rupture after bag-mask-ventilation

    PubMed Central

    Bednarz, Stephan; Filipovic, Miodrag; Schoch, Otto; Mauermann, Eckhard

    2015-01-01

    A 42 year old woman underwent bronchoscopy with procedural propofol sedation. During the procedure, the patient suffered respiratory arrest, and bag-mask ventilation was initiated. During forced mask ventilation, abdominal distention occurred. Even after correct placement of an endotracheal and a nasogastric tube, high inspiratory pressures persisted. The abdominal CT scan revealed a high amount of intraperitoneal free air. An emergent laparotomy confirmed a stomach rupture. Immediately after opening of the peritoneal cavity, peak ventilatory pressures decreased. In this case forceful bag-mask ventilation led to air insufflation into the stomach, increasing gastric pressure, and consecutive stomach rupture.

  16. Using a Ventilation Controller to Optimize Residential Passive Ventilation For Energy and Indoor Air Quality

    SciTech Connect

    Turner, William; Walker, Iain

    2014-08-01

    One way to reduce the energy impact of providing residential ventilation is to use passive and hybrid systems. However, these passive and hybrid (sometimes called mixed-mode) systems must still meet chronic and acute health standards for ventilation. This study uses a computer simulation approach to examine the energy and indoor air quality (IAQ) implications of passive and hybrid ventilation systems, in 16 California climate zones. Both uncontrolled and flow controlled passive stacks are assessed. A new hybrid ventilation system is outlined that uses an intelligent ventilation controller to minimise energy use, while ensuring chronic and acute IAQ standards are met. ASHRAE Standard 62.2-2010 – the United States standard for residential ventilation - is used as the chronic standard, and exposure limits for PM2.5, formaldehyde and NO2 are used as the acute standards.The results show that controlled passive ventilation and hybrid ventilation can be used in homes to provide equivalent IAQ to continuous mechanical ventilation, for less use of energy.

  17. Tunnel ventilation effectiveness in fire scenarios 

    E-print Network

    Colella, Francesco; Rein, Guillermo; Carvel, Ricky O; Torero, Jose L

    2010-01-01

    Throughout most of a tunnel network the ventilation behaviour may be approximated with a simple 1D flow model. However, there are some important - but relatively small - regions of the tunnel that require CFD analysis. The ...

  18. Innovative ventilation system for animal anatomy laboratory

    SciTech Connect

    Lacey, D.R.; Smith, D.C.

    1997-04-01

    A unique ventilation system was designed and built to reduce formaldehyde fumes in the large animal anatomy lab at the Vet Medical Center at Cornell University. The laboratory includes four rooms totaling 5,500 ft{sup 2}. The main room has 2,300 ft{sup 2} and houses the laboratory where up to 60 students dissect as many as 12 horses at a time. Other rooms are a cold storage locker, an animal preparation room and a smaller lab for specialized instruction. The large animal anatomy laboratory has a history of air quality complaints despite a fairly high ventilation rate of over 10 air changes/hour. The horses are embalmed, creating a voluminous source of formaldehyde and phenol vapors. Budget constraints and increasingly stringent exposure limits for formaldehyde presented a great challenge to design a ventilation system that yields acceptable air quality. The design solution included two innovative elements: air-to-air heat recovery, and focused ventilation.

  19. 46 CFR 111.15-10 - Ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Storage Batteries and Battery Chargers: Construction and Installation § 111...General. Each room, locker, and box for storage batteries must be arranged or ventilated to prevent...

  20. 46 CFR 111.15-10 - Ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Storage Batteries and Battery Chargers: Construction and Installation § 111...General. Each room, locker, and box for storage batteries must be arranged or ventilated to prevent...

  1. 46 CFR 111.15-10 - Ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Storage Batteries and Battery Chargers: Construction and Installation § 111...General. Each room, locker, and box for storage batteries must be arranged or ventilated to prevent...

  2. EVALUATION OF VENTILATION PERFORMANCE FOR INDOOR SPACE

    EPA Science Inventory

    The paper discusses a personal-computer-based application of computational fluid dynamics that can be used to determine the turbulent flow field and time-dependent/steady-state contaminant concentration distributions within isothermal indoor space. (NOTE: Ventilation performance ...

  3. Eustachian tube function after transmyringeal ventilation.

    PubMed

    Gupta, S C; Malhotra, M; Singh, M

    2005-01-01

    This study anus at determining the effect of transmyringeal ventilation on Eustachian tube functions. Seventy ears clinically diagnosed as having otitis media with effusion or grade I and II retraction of pars-tensa of tympanic membrane were treated with antiallergics, decongestants, mucolytics, and antibiotics as required for maximum upto three months. In forty-five ears that showed neither symptomatic nor audiometric improvement, transmyringeal ventilation was restored by myringotomy and ventilation tube insertion. There after, Eustachian tube functions were assessed by using pressure equilibration test. The post-operative audiograms showed mean hearing gain of 16. 6 dB (S D±7.9) in majority (96%) of the ears. At first week 93% ears could not either totally or partially equilibrate positive or negative pressure. The percentage in the poor function group remained 91% even at the end of 6 months showing no significant effect of ventilation tube insertion on active ET functions. PMID:23120122

  4. 30 CFR 75.333 - Ventilation controls.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...for the construction of overcasts, undercasts, shaft partitions, permanent stoppings, and regulators include concrete, concrete block, brick, cinder block, tile, or steel. No ventilation controls installed after November 15, 1992,...

  5. 30 CFR 75.333 - Ventilation controls.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...for the construction of overcasts, undercasts, shaft partitions, permanent stoppings, and regulators include concrete, concrete block, brick, cinder block, tile, or steel. No ventilation controls installed after November 15, 1992,...

  6. 46 CFR 98.25-75 - Ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk § 98.25-75 Ventilation. (a) All enclosed spaces containing cargo tanks fitted with bottom...

  7. 46 CFR 98.25-75 - Ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk § 98.25-75 Ventilation. (a) All enclosed spaces containing cargo tanks fitted with bottom...

  8. 46 CFR 98.25-75 - Ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk § 98.25-75 Ventilation. (a) All enclosed spaces containing cargo tanks fitted with bottom...

  9. 46 CFR 98.25-75 - Ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk § 98.25-75 Ventilation. (a) All enclosed spaces containing cargo tanks fitted with bottom...

  10. 46 CFR 98.25-75 - Ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk § 98.25-75 Ventilation. (a) All enclosed spaces containing cargo tanks fitted with bottom...

  11. Midlevel ventilation's constraint on tropical cyclone intensity

    E-print Network

    Tang, Brian Hong-An

    2010-01-01

    Midlevel ventilation, or the flux of low-entropy air into the inner core of a tropical cyclone (TC), is a hypothesized mechanism by which environmental vertical wind shear can constrain a TC's intensity. An idealized ...

  12. Midlevel Ventilation's Constraint on Tropical Cyclone Intensity

    E-print Network

    Tang, Brian Hong-An

    Midlevel ventilation, or the flux of low-entropy air into the inner core of a tropical cyclone (TC), is a hypothesized mechanism by which environmental vertical wind shear can constrain a tropical cyclone’s intensity. An ...

  13. A Ventilation Index for Tropical Cyclones

    E-print Network

    Tang, Brian

    An important environmental control of both tropical cyclone intensity and genesis is vertical wind shear. One hypothesized pathway by which vertical shear affects tropical cyclones is midlevel ventilation—or the flux of ...

  14. 46 CFR 194.10-25 - Ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... not less than 1/8-inch mesh. Metal watertight closures shall be provided for use when the ventilation.... Louvers or weather cowls with a double layer of wire screen of not less than 1/8-inch mesh shall...

  15. 46 CFR 111.15-10 - Ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Storage Batteries and Battery Chargers: Construction and Installation § 111...General. Each room, locker, and box for storage batteries must be arranged or ventilated to prevent...

  16. 46 CFR 111.15-10 - Ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Storage Batteries and Battery Chargers: Construction and Installation § 111...General. Each room, locker, and box for storage batteries must be arranged or ventilated to prevent...

  17. Floor-supply displacement ventilation system

    E-print Network

    Kobayashi, Nobukazu, 1967-

    2001-01-01

    Research on indoor environments has received more attention recently because reports of symptoms and other health complaints related to indoor environments have been increasing. Heating, ventilating, and air-conditioning ...

  18. Process control migration towards LHC ventilation functionality

    E-print Network

    Blanc, D

    2003-01-01

    The adaptation of the ventilation systems as well as the integration of equipment to fit with the new LHC ventilation requirements lead us to consider a global re-engineering of the existing control system. This, decade old process control structure is composed of elements which are mixed between industrial and home made devices. The proposed modifications are made in order to upgrade the present control system and to provide efficient and well adapted control architecture to integrate the LHC ventilation equipment of the injection tunnels. Moreover, we need a plan for the next fifteen years of the LHC life cycle. The document is to present the situation of the present control system of the LEP ventilation process and to propose a plan for the migration of the control architecture. This is done considering the fact that elements of the present control infrastructure could no longer be supported from 2003 and major components must be removed from the CERN communication infrastructure.

  19. Scale model studies of displacement ventilation

    E-print Network

    Okutan, Galip Mehmet

    1995-01-01

    Displacement ventilation is an air conditioning method that provides conditioned air to indoor environments with the goal to improve air quality while reducing energy consumption. This study investigates the performance ...

  20. Engineering work plan and design basis for 241-SY ventilation improvements

    SciTech Connect

    Andersen, J.A.

    1997-05-19

    There are three tanks in the 241-SY tank farm. Tank 241-SY101 and 241-SY-103 are flammable gas watch list tanks. Tank 241-SY-102 is included in the ventilation improvement process in an effort to further control air flow in the tank farm. This tank farm has only one outlet ventilation port for all three tanks. Flammable gas is released (may be steady and/or periodic) from the waste in the primary tank vapor space. The gas is removed from the tank by an active ventilation system. However, maintaining consistent measurable flow through the tank can be problematic due to the poor control capabilities of existing equipment. Low flow through the tank could allow flammable gas to build up in the tank and possibly exceed the lower flammability limit (LFL), prevent the most rapid removal of flammable gas from the tank after a sudden gas release, and/or cause high vacuum alarms to sound. Using the inlet and outlet down stream butterfly valves performs the current method of controlling flow in tank farm 241-SY. A filter station is installed on the inlet of each tank, but controlling air flow with its 12 inch butterfly valve is difficult. There is also in-leakage through pump and valve pits. Butterfly valves on the downstream side of each tank could also be used to control air flow. However, their large size and the relatively low air velocity make this control method also ineffective. The proposed method of optimizing tank air flow and pressure control capability is to install an air flow controller on the inlet of each existing filter station in SY farm, and seal as best as practical all other air leakage paths. Such air flow controllers have been installed on 241-AN and 241-AW tanks (see drawing H-2-85647).

  1. Perioperative lung protective ventilation in obese patients.

    PubMed

    Fernandez-Bustamante, Ana; Hashimoto, Soshi; Serpa Neto, Ary; Moine, Pierre; Vidal Melo, Marcos F; Repine, John E

    2015-01-01

    The perioperative use and relevance of protective ventilation in surgical patients is being increasingly recognized. Obesity poses particular challenges to adequate mechanical ventilation in addition to surgical constraints, primarily by restricted lung mechanics due to excessive adiposity, frequent respiratory comorbidities (i.e. sleep apnea, asthma), and concerns of postoperative respiratory depression and other pulmonary complications. The number of surgical patients with obesity is increasing, and facing these challenges is common in the operating rooms and critical care units worldwide. In this review we summarize the existing literature which supports the following recommendations for the perioperative ventilation in obese patients: (1) the use of protective ventilation with low tidal volumes (approximately 8 mL/kg, calculated based on predicted -not actual- body weight) to avoid volutrauma; (2) a focus on lung recruitment by utilizing PEEP (8-15 cmH2O) in addition to recruitment maneuvers during the intraoperative period, as well as incentivized deep breathing and noninvasive ventilation early in the postoperative period, to avoid atelectasis, hypoxemia and atelectrauma; and (3) a judicious oxygen use (ideally less than 0.8) to avoid hypoxemia but also possible reabsorption atelectasis. Obesity poses an additional challenge for achieving adequate protective ventilation during one-lung ventilation, but different lung isolation techniques have been adequately performed in obese patients by experienced providers. Postoperative efforts should be directed to avoid hypoventilation, atelectasis and hypoxemia. Further studies are needed to better define optimum protective ventilation strategies and analyze their impact on the perioperative outcomes of surgical patients with obesity. PMID:25907273

  2. Recovering Energy From Ventilation and Process Airstreams 

    E-print Network

    Cheney, W. A.

    1986-01-01

    cleaners for exhaust ventilation systems to permit recirculation. 2. Placing heat exchangers in process stacks and general ventilation air streams, and 3. Collecting hydrocarbon contaminants from process stacks and reusing or selling them.... In this paper I will touch on condensa tion and electrostatic precipitation as methods that can be used to collect and reuse in some form, hydrocarbons from process stacks. HEAT EXCHANGERS Plate-~ype, air-to-air heat exchangers move hot, dirty exhaust...

  3. Sensor-based demand controlled ventilation

    SciTech Connect

    De Almeida, A.T.; Fisk, W.J.

    1997-07-01

    In most buildings, occupancy and indoor pollutant emission rates vary with time. With sensor-based demand-controlled ventilation (SBDCV), the rate of ventilation (i.e., rate of outside air supply) also varies with time to compensate for the changes in pollutant generation. In other words, SBDCV involves the application of sensing, feedback and control to modulate ventilation. Compared to ventilation without feedback, SBDCV offers two potential advantages: (1) better control of indoor pollutant concentrations; and (2) lower energy use and peak energy demand. SBDCV has the potential to improve indoor air quality by increasing the rate of ventilation when indoor pollutant generation rates are high and occupants are present. SBDCV can also save energy by decreasing the rate of ventilation when indoor pollutant generation rates are low or occupants are absent. After providing background information on indoor air quality and ventilation, this report provides a relatively comprehensive discussion of SBDCV. Topics covered in the report include basic principles of SBDCV, sensor technologies, technologies for controlling air flow rates, case studies of SBDCV, application of SBDCV to laboratory buildings, and research needs. SBDCV appears to be an increasingly attractive technology option. Based on the review of literature and theoretical considerations, the application of SBDCV has the potential to be cost-effective in applications with the following characteristics: (a) a single or small number of dominant pollutants, so that ventilation sufficient to control the concentration of the dominant pollutants provides effective control of all other pollutants; (b) large buildings or rooms with unpredictable temporally variable occupancy or pollutant emission; and (c) climates with high heating or cooling loads or locations with expensive energy.

  4. Evaluating Ventilation Systems for Existing Homes

    SciTech Connect

    Aldrich, Robb; Arena, Lois

    2013-02-01

    In an effort to improve housing options near Las Vegas, Nevada, the Clark County Community Resources Division (CCCRD) performs substantial renovations to foreclosed homes. After dramatic energy, aesthetic, and health and safety improvements are made, homes are rented or sold to qualified residents. This report describes the evaluation and selection of ventilation systems for these homes, including key considerations when selecting an ideal system. The report then describes CCCRD’s decision process with respect to ventilation.

  5. Demand Controlled Ventilation for Improved Humidity Control 

    E-print Network

    Rogers, J. K.

    1996-01-01

    Ventilation for Improved Humidity Control James K. Rogers, P.E. One Blacksmith Road Chelmsford, Massachusetts ABSTRACT Recently introduced technology makes it possible to continuously monitor for humidity in numerous buildmg areas using a multi..., outside air can be minimized without exceeding recommended IAQ guidelines. INTRODUCTION The greatest single contributor to building energy loads in humid climates is the cooling and dehumidifying of outside air which is brought in for ventilation...

  6. Clinical review: Long-term noninvasive ventilation

    PubMed Central

    Robert, Dominique; Argaud, Laurent

    2007-01-01

    Noninvasive positive ventilation has undergone a remarkable evolution over the past decades and is assuming an important role in the management of both acute and chronic respiratory failure. Long-term ventilatory support should be considered a standard of care to treat selected patients following an intensive care unit (ICU) stay. In this setting, appropriate use of noninvasive ventilation can be expected to improve patient outcomes, reduce ICU admission, enhance patient comfort, and increase the efficiency of health care resource utilization. Current literature indicates that noninvasive ventilation improves and stabilizes the clinical course of many patients with chronic ventilatory failure. Noninvasive ventilation also permits long-term mechanical ventilation to be an acceptable option for patients who otherwise would not have been treated if tracheostomy were the only alternative. Nevertheless, these results appear to be better in patients with neuromuscular/-parietal disorders than in chronic obstructive pulmonary disease. This clinical review will address the use of noninvasive ventilation (not including continuous positive airway pressure) mainly in diseases responsible for chronic hypoventilation (that is, restrictive disorders, including neuromuscular disease and lung disease) and incidentally in others such as obstructive sleep apnea or problems of central drive. PMID:17419882

  7. Created: July, 2014 Laboratory Safety Design Guide Section 3 Laboratory Ventilation

    E-print Network

    Created: July, 2014 Laboratory Safety Design Guide Section 3 ­ Laboratory Ventilation 3-1 Section 3 LABORATORY VENTILATION Contents A. Scope .................................................................................................................3-2 B. General Laboratory Ventilation

  8. Tracer dating and ocean ventilation

    SciTech Connect

    Thiele, G.; Sarmiento, J.L. )

    1990-06-15

    The interpretation of transient tracer observations depends on difficult to obtain information on the evolution in time of the tracer boundary conditions and interior distributions. Recent studies have attempted to circumvent this problem by making use of a derived quantity, age, based on the simultaneous distribution of two complementary tracers, such as tritium and its daughter, helium 3. The age is defined with reference to the surface such that the boundary condition takes on a constant value of zero. The authors use a two-dimensional model to explore the circumstances under which such a combination of conservation equations for two complementary tracers can lead to a cancellation of the time derivative terms. An interesting aspect of this approach is that mixing can serve as a source or sink of tracer based age. The authors define an idealized ventilation age tracer that is conservative with respect to mixing, and they explore how its behavior compares with that of the tracer-based ages over a range of advective and diffusive parameters.

  9. Ventilation efficiencies of a desk-edge-mounted task ventilation system

    SciTech Connect

    Faulkner, David; Fisk, William J.; Sullivan, Douglas P.; Lee, Seung Min

    2002-03-01

    In chamber experiments, we investigated the effectiveness of a task ventilation system with an air supply nozzle located underneath the front edge of a desk and directing air toward a heated mannequin seated at the desk. The task ventilation system provided outside air, while another ventilation system provided additional space cooling but no outside air. Test variables included the vertical angle of air supply (-15{sup o} to 45{sup o} from horizontal), and the supply flow rate of (3.5 to 6.5 L s{sup -1}). Using the tracer gas step-up and step-down procedures, the measured air change effectiveness (i.e., exhaust air age divided by age of air at the mannequin's face) ranged from 1.4 to 2.7, which is higher than typically reported for commercially available task ventilation or displacement ventilation systems.

  10. Regenerative Blower for EVA Suit Ventilation Fan

    NASA Technical Reports Server (NTRS)

    Izenson, Michael G.; Chen, Weibo; Paul, Heather L.

    2010-01-01

    Portable life support systems in future space suits will include a ventilation subsystem driven by a dedicated fan. This ventilation fan must meet challenging requirements for pressure rise, flow rate, efficiency, size, safety, and reliability. This paper describes research and development that showed the feasibility of a regenerative blower that is uniquely suited to meet these requirements. We proved feasibility through component tests, blower tests, and design analysis. Based on the requirements for the Constellation Space Suit Element (CSSE) Portable Life Support System (PLSS) ventilation fan, we designed the critical elements of the blower. We measured the effects of key design parameters on blower performance using separate effects tests, and used the results of these tests to design a regenerative blower that will meet the ventilation fan requirements. We assembled a proof-of-concept blower and measured its performance at sub-atmospheric pressures that simulate a PLSS ventilation loop environment. Head/flow performance and maximum efficiency point data were used to specify the design and operating conditions for the ventilation fan. We identified materials for the blower that will enhance safety for operation in a lunar environment, and produced a solid model that illustrates the final design. The proof-of-concept blower produced the flow rate and pressure rise needed for the CSSE ventilation subsystem while running at 5400 rpm, consuming only 9 W of electric power using a non-optimized, commercial motor and controller and inefficient bearings. Scaling the test results to a complete design shows that a lightweight, compact, reliable, and low power regenerative blower can meet the performance requirements for future space suit life support systems.

  11. Hydrostatic Hyperbaric Chamber Ventilation System

    NASA Technical Reports Server (NTRS)

    Sarguisingh, Miriam J.

    2012-01-01

    The hydrostatic hyperbaric chamber (HHC) represents the merger of several technologies in development for NASA aerospace applications, harnessed to directly benefit global health. NASA has significant experience developing composite hyperbaric chambers for a variety of applications. NASA also has researched the application of water-filled vessels to increase tolerance of acceleration forces. The combination of these two applications has resulted in the hydrostatic chamber, which has been conceived as a safe, affordable means of making hyperbaric oxygen therapy (HBOT) available in the developing world for the treatment of a variety of medical conditions. Specifically, HBOT is highly-desired as a possibly curative treatment for Buruli Ulcer, an infectious condition that afflicts children in sub-Saharan Africa. HBOT is simply too expensive and too dangerous to implement in the developing world using standard equipment. The HHC technology changes the paradigm. The HHC differs from standard hyperbaric chambers in that the majority of its volume is filled with water which is pressurized by oxygen being supplied in the portion of the chamber containing the patient s head. This greatly reduces the amount of oxygen required to sustain a hyperbaric atmosphere, thereby making the system more safe and economical to operate. An effort was taken to develop an HHC system to apply HBOT to children that is simple and robust enough to support transport, assembly, maintenance and operation in developing countries. This paper details the concept for an HHC ventilation and pressurization system to provide controlled pressurization and adequate washout of carbon dioxide while the subject is enclosed in the confined space during the administration of the medical treatment. The concept took into consideration operational complexity, safety to the patient and operating personnel, and physiological considerations. The simple schematic, comprised of easily acquired commercial hardware, supports sustainability.

  12. Hydrostatic Hyperbaric Chamber Ventilation System

    NASA Technical Reports Server (NTRS)

    Sargusingh, Miriam M.

    2011-01-01

    The hydrostatic hyperbaric chamber (HHC) represents the merger of several technologies in development for NASA aerospace applications, harnessed to directly benefit global health. NASA has significant experience developing composite hyperbaric chambers for a variety of applications, including the treatment of medical conditions. NASA also has researched the application of water-filled vessels to increase tolerance of acceleration forces. The combination of these two applications has resulted in the hydrostatic chamber, which has been conceived as a safe, affordable means of making hyperbaric oxygen therapy available in the developing world for the treatment of a variety of medical conditions. Specifically, hyperbaric oxygen therapy is highly-desired as a possibly curative treatment for Buruli Ulcer, an infectious condition that afflicts children in sub-Saharan Africa. Hyperbaric oxygen therapy is simply too expensive and too dangerous to implement in the developing world using standard equipment. The hydrostatic hyperbaric chamber technology changes the paradigm. The HHC differs from standard hyperbaric chambers in that the majority of its volume is filled with water which is pressurized by oxygen being supplied in the portion of the chamber containing the patient s head. This greatly reduces the amount of oxygen required to sustain a hyperbaric atmosphere, thereby making the system more safe and economical to operate. An effort was taken to develop an HHC system to apply HBOT to children that is simple and robust enough to support transport, assembly, maintenance and operation in developing countries. This paper details the concept for an HHC ventilation and pressurization system that will provide controlled pressurization of the system, and provide adequate washout of carbon dioxide while the subject is enclosed in the confined space during the administration of the medical treatment. The concept took into consideration operational complexity, safety to the patient and operating personnel, and physiological considerations. The simple schematic, comprised of easily acquired commercial hardware, supports sustainability.

  13. WASTE TREATMENT BUILDING VENTILATION SYSTEM DESCRIPTION DOCUMENT

    SciTech Connect

    P.A. Kumar

    2000-06-22

    The Waste Treatment Building Ventilation System provides heating, ventilation, and air conditioning (HVAC) for the contaminated, potentially contaminated, and uncontaminated areas of the Monitored Geologic Repository's (MGR) Waste Treatment Building (WTB). In the uncontaminated areas, the non-confinement area ventilation system maintains the proper environmental conditions for equipment operation and personnel comfort. In the contaminated and potentially contaminated areas, in addition to maintaining the proper environmental conditions for personnel comfort and equipment operation, the contamination confinement area ventilation system directs potentially contaminated air away from personnel in the WTB and confines the contamination within high-efficiency particulate air (HEPA) filtration units. The contamination confinement area ventilation system creates airflow paths and pressure zones to minimize the potential for spreading contamination with the building. The contamination confinement ventilation system also protects the environment and the public by limiting airborne releases of radioactive or other hazardous contaminants from the WTB. The Waste Treatment Building Ventilation System confines the radioactive and hazardous material within the building such that the release rates comply with regulatory limits, The system design, operations, and maintenance activities incorporate ALARA (as low as is reasonably achievable) principles to maintain personnel radiation doses to all occupational workers below regulatory limits and as low as is reasonably achievable. The system provides status of important system parameters and equipment operation, and provides audible and/or visual indication of off-normal conditions and equipment failures. The Waste Treatment Building Ventilation System interfaces with the Waste Treatment Building System by being located in the WTB, and by maintaining specific pressure, temperature, and humidity environments within the building. The system also depends on the WTB for normal electric power supply and the required supply of water for heating, cooling, and humidification. Interface with the Waste Treatment Building System includes the WTB fire protection subsystem for detection of fire and smoke. The Waste Treatment Building Ventilation System interfaces with the Site Radiological Monitoring System for continuous monitoring of the exhaust air and key areas within the WTB, the Monitored Geologic Repository Operations Monitoring and Control System for monitoring and control of system operations, and the Site Generated Radiological Waste Handling System and Site Generated Hazardous, Non-Hazardous & Sanitary Waste Disposal System for routing of pretreated toxic, corrosive, and radiologically contaminated effluent from process equipment to the HEPA filter exhaust ductwork and air-cleaning unit.

  14. WASTE HANDLING BUILDING VENTILATION SYSTEM DESCRIPTION DOCUMENT

    SciTech Connect

    P.A. Kumar

    2000-06-21

    The Waste Handling Building Ventilation System provides heating, ventilation, and air conditioning (HVAC) for the contaminated, potentially contaminated, and uncontaminated areas of the Monitored Geologic Repository's (MGR) Waste Handling Building (WHB). In the uncontaminated areas, the non-confinement area ventilation system maintains the proper environmental conditions for equipment operation and personnel comfort. In the contaminated and potentially contaminated areas, in addition to maintaining the proper environmental conditions for equipment operation and personnel comfort, the contamination confinement area ventilation system directs potentially contaminated air away from personnel in the WHB and confines the contamination within high-efficiency particulate air (HEPA) filtration units. The contamination confinement areas ventilation system creates airflow paths and pressure zones to minimize the potential for spreading contamination within the building. The contamination confinement ventilation system also protects the environment and the public by limiting airborne releases of radioactive or other hazardous contaminants from the WHB. The Waste Handling Building Ventilation System is designed to perform its safety functions under accident conditions and other Design Basis Events (DBEs) (such as earthquakes, tornadoes, fires, and loss of the primary electric power). Additional system design features (such as compartmentalization with independent subsystems) limit the potential for cross-contamination within the WHB. The system provides status of important system parameters and equipment operation, and provides audible and/or visual indication of off-normal conditions and equipment failures. The Waste Handling Building Ventilation System confines the radioactive and hazardous material within the building such that the release rates comply with regulatory limits. The system design, operations, and maintenance activities incorporate ALARA (as low as is reasonably achievable) principles to maintain personnel radiation doses to all occupational workers below regulatory limits and as low as is reasonably achievable. The Waste Handling Building Ventilation System interfaces with the Waste Handling Building System by being located within the WHB and by maintaining specific pressures, temperatures, and humidity within the building. The system also depends on the WHB for water supply. The system interfaces with the Site Radiological Monitoring System for continuous monitoring of the exhaust air; the Waste Handling Building Fire Protection System for detection of fire and smoke; the Waste Handling Building Electrical System for normal, emergency, and standby power; and the Monitored Geologic Repository Operations Monitoring and Control System for monitoring and control of the system.

  15. Design Feature 7: Continuous Preclosure Ventilation

    SciTech Connect

    A.T. Watkins

    1999-06-22

    This design feature (DF) is intended to evaluate the effects of continuous ventilation in the emplacement drifts during preclosure and how the effects, if any, compare to the Viability Assessment (VA) reference design for postclosure long term performance. This DF will be evaluated against a set of criteria provided by the License Application Design Selection (LADS) group. The VA reference design included a continuous ventilation airflow quantity of 0.1 m{sup 3}/s in the emplacement drifts in the design of the repository subsurface facilities. The effects of this continuous ventilation during the preclosure was considered to have a negligible effect on postclosure performance and therefore is not included during postclosure in the assessment of the long term performance. This DF discusses the effects of continuous ventilation on the emplacement drift environment and surrounding rock conditions during preclosure for three increased airflow quantities. The three cases of continuous ventilation systems are: System A, 1.0 m{sup 3}/s (Section 8), System B, 5.0 m{sup 3}/s (Section 9), and System C, 10.0 m{sup 3}/s (Section 10) in each emplacement drift split. An emplacement drift split is half total length of emplacement drift going from the east or west main to the exhaust main. The difference in each system is the quantity of airflow in the emplacement drifts.

  16. Computational fluid dynamics in ventilation: Practical approach

    NASA Astrophysics Data System (ADS)

    Fontaine, J. R.

    The potential of computation fluid dynamics (CFD) for conceiving ventilation systems is shown through the simulation of five practical cases. The following examples are considered: capture of pollutants on a surface treating tank equipped with a unilateral suction slot in the presence of a disturbing air draft opposed to suction; dispersion of solid aerosols inside fume cupboards; performances comparison of two general ventilation systems in a silkscreen printing workshop; ventilation of a large open painting area; and oil fog removal inside a mechanical engineering workshop. Whereas the two first problems are analyzed through two dimensional numerical simulations, the three other cases require three dimensional modeling. For the surface treating tank case, numerical results are compared to laboratory experiment data. All simulations are carried out using EOL, a CFD software specially devised to deal with air quality problems in industrial ventilated premises. It contains many analysis tools to interpret the results in terms familiar to the industrial hygienist. Much experimental work has been engaged to validate the predictions of EOL for ventilation flows.

  17. Efficacy of intermittent ventilation for providing acceptable indoor air quality

    SciTech Connect

    Sherman, M.H.

    2004-10-01

    Ventilation standards and guidelines typically treat ventilation as a constant and specify its value. In many circumstances a designer wishes to use intermittent ventilation, rather than constant ventilation, but there are no easy equivalencies available. This report develops a model of efficacy that allows one to calculate how much intermittent ventilation one needs to get the same indoor air quality as a the continuous value specified. We have found that there is a simple relationship between three dimensionless quantities: the temporal ventilation effectiveness (which we call the efficacy), the nominal turn-over and the under-ventilation fraction. This relationship allows the calculation of intermittent ventilation for a wide variety of parameters and conditions. We can use the relationship to define a critical time that separates the regime in which ventilation variations can be averaged over from the regime in which variable ventilation is of low effectiveness. We have found that ventilation load-shifting, temporary protection against poor outdoor air quality and dynamic ventilation strategies can be quite effective in low-density buildings such as single-family houses or office spaces. The results of this work enable ventilation standards and guidelines to allow this extra flexibility and still provide acceptable indoor air quality.

  18. 46 CFR 116.600 - Ventilation of enclosed and partially enclosed spaces.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...the purpose of the space. (b) A power ventilation system must be capable of being shut down from...regular basis must be ventilated by a power ventilation system unless natural ventilation in all ordinary weather conditions is...

  19. 30 CFR 57.8531 - Construction and maintenance of ventilation doors.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Construction and maintenance of ventilation doors. 57.8531 Section 57...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Ventilation Underground Only § 57.8531 Construction and maintenance of ventilation doors. Ventilation doors...

  20. 30 CFR 57.8531 - Construction and maintenance of ventilation doors.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Construction and maintenance of ventilation doors. 57.8531 Section 57...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Ventilation Underground Only § 57.8531 Construction and maintenance of ventilation doors. Ventilation doors...

  1. 30 CFR 57.8531 - Construction and maintenance of ventilation doors.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Construction and maintenance of ventilation doors. 57.8531 Section 57...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Ventilation Underground Only § 57.8531 Construction and maintenance of ventilation doors. Ventilation doors...

  2. 30 CFR 57.8531 - Construction and maintenance of ventilation doors.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Construction and maintenance of ventilation doors. 57.8531 Section 57...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Ventilation Underground Only § 57.8531 Construction and maintenance of ventilation doors. Ventilation doors...

  3. 30 CFR 57.8531 - Construction and maintenance of ventilation doors.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Construction and maintenance of ventilation doors. 57.8531 Section 57...STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Ventilation Underground Only § 57.8531 Construction and maintenance of ventilation doors. Ventilation doors...

  4. Preliminary Simulations of the Ullage Dynamics in Microgravity During the Jet Mixing Portion of Tank Pressure Control Experiments

    NASA Technical Reports Server (NTRS)

    Breisacher, Kevin; Moder, Jeffrey

    2015-01-01

    The results of CFD simulations of microgravity tank pressure control experiments performed on the Space Shuttle are presented. A 13.7 liter acrylic model tank was used in these experiments. The tank was filled to an 83 percent fill fraction with Freon refrigerant to simulate cryogenic propellants stored in space. In the experiments, a single liquid jet near the bottom of the tank was used for mixing the tank. Simulations at a range of jet Weber numbers were performed. Qualitative comparisons of the liquid and gas interface dynamics observed and recorded in the experiments and those computed are shown and discussed. The simulations were able to correctly capture jet penetration of the ullage, qualitatively reproduce ullage shapes and dynamics, as well as the final equilibrium position of the ullage.

  5. Preliminary Simulations of the Ullage Dynamics in Microgravity during the Jet Mixing Portion of Tank Pressure Control Experiments

    NASA Technical Reports Server (NTRS)

    Breisacher, Kevin; Moder, Jeffrey

    2015-01-01

    The results of CFD simulations of microgravity tank pressure control experiments performed on the Space Shuttle are presented. A 13.7 liter acrylic model tank was used in these experiments. The tank was filled to an 83 percent fill fraction with Freon refrigerant to simulate cryogenic propellants stored in space. In the experiments, a single liquid jet near the bottom of the tank was used for mixing the tank. Simulations at a range of jet Weber numbers were performed. Qualitative comparisons of the liquid and gas interface dynamics observed and recorded in the experiments and those computed are shown and discussed. The simulations were able to correctly capture jet penetration of the ullage, qualitatively reproduce ullage shapes and dynamics, as well as the final equilibrium position of the ullage.

  6. Estimated costs of ventilation systems complying with the HUD ventilation standard for manufactured homes

    SciTech Connect

    Miller, J.D.; Conner, C.C.

    1993-11-01

    At the request of the US Department of Housing and Urban Development (HUD), the Pacific Northwest Laboratory estimated the material, labor, and operating costs for ventilation equipment needed for compliance with HUD`s proposed revision to the ventilation standard for manufactured housing. This was intended to bound the financial impacts of the ventilation standard revision. Researchers evaluated five possible prototype ventilation systems that met the proposed ventilation requirements. Of those five, two systems were determined to be the most likely used by housing manufacturers: System 1 combines a fresh air duct with the existing central forced-air system to supply and circulate fresh air to conditioned spaces. System 2 uses a separate exhaust fan to remove air from the manufactured home. The estimated material and labor costs for these two systems range from $200 to $300 per home. Annual operating costs for the two ventilation systems were estimated for 20 US cities. The estimated operating costs for System 1 ranged from $55/year in Las Vegas, Nevada, to $83/year in Bismarck, North Dakota. Operating costs for System 2 ranged from a low of $35/year in Las Vegas to $63/year in Bismarck. Thus, HUD`s proposed increase in ventilation requirements will add less than $100/year to the energy cost of a manufactured home.

  7. MODELING VENTILATION SYSTEM RESPONSE TO FIRE

    SciTech Connect

    Coutts, D

    2007-04-17

    Fires in facilities containing nuclear material have the potential to transport radioactive contamination throughout buildings and may lead to widespread downwind dispersal threatening both worker and public safety. Development and implementation of control strategies capable of providing adequate protection from fire requires realistic characterization of ventilation system response which, in turn, depends on an understanding of fire development timing and suppression system response. This paper discusses work in which published HEPA filter data was combined with CFAST fire modeling predictions to evaluate protective control strategies for a hypothetical DOE non-reactor nuclear facility. The purpose of this effort was to evaluate when safety significant active ventilation coupled with safety class passive ventilation might be a viable control strategy.

  8. Flow measurement in mechanical ventilation: a review.

    PubMed

    Schena, Emiliano; Massaroni, Carlo; Saccomandi, Paola; Cecchini, Stefano

    2015-03-01

    Accurate monitoring of flow rate and volume exchanges is essential to minimize ventilator-induced lung injury. Mechanical ventilators employ flowmeters to estimate the amount of gases delivered to patients and use the flow signal as a feedback to adjust the desired amount of gas to be delivered. Since flowmeters play a crucial role in this field, they are required to fulfill strict criteria in terms of dynamic and static characteristics. Therefore, mechanical ventilators are equipped with only the following kinds of flowmeters: linear pneumotachographs, fixed and variable orifice meters, hot wire anemometers, and ultrasonic flowmeters. This paper provides an overview of these sensors. Their working principles are described together with their relevant advantages and disadvantages. Furthermore, the most promising emerging approaches for flowmeters design (i.e., fiber optic technology and three dimensional micro-fabrication) are briefly reviewed showing their potential for this application. PMID:25659299

  9. Building ventilation and indoor air quality

    SciTech Connect

    Hollowell, C.D.; Berk, J.V.; Boegel, M.L.; Miksch, R.R.; Nazaroff, W.W.; Traynor, G.W.

    1980-01-01

    Rising energy prices, among other factors, have generated an incentive to reduce ventilation rates and thereby reduce the cost of heating and cooling buildings. Reduced infiltration and ventilation in buildings may significantly increase exposure to indoor contaminants and perhaps have adverse effects on occupant health and comfort. Four indoor air contaminants - carbon monoxide and nitrogen dioxide from gas appliances; formaldehyde from particleboard, plywood, urea-formaldehyde foam insulation, and gas appliances; and radon from building materials, soil, and ground water - are currently receiving considerable attention in the context of potential health risks associated with reduced infiltration and ventilation rates. These air contaminants in conventional and energy efficient buildings were measured and analyzed with a view to assessing their potential health risks and various control strategies capable of lowering pollutant concentrations. Preliminary findings suggest that further intensive studies are needed in order to develop criteria for maintaining acceptable indoor air quality without compromising energy efficiency.

  10. Thermoregulation and ventilation of termite mounds

    NASA Astrophysics Data System (ADS)

    Korb, Judith

    2003-05-01

    Some of the most sophisticated of all animal-built structures are the mounds of African termites of the subfamily Macrotermitinae, the fungus-growing termites. They have long been studied as fascinating textbook examples of thermoregulation or ventilation of animal buildings. However, little research has been designed to provide critical tests of these paradigms, derived from a very small number of original papers. Here I review results from recent studies on Macrotermes bellicosus that considered the interdependence of ambient temperature, thermoregulation, ventilation and mound architecture, and that question some of the fundamental paradigms of termite mounds. M. bellicosus achieves thermal homeostasis within the mound, but ambient temperature has an influence too. In colonies in comparably cool habitats, mound architecture is adapted to reduce the loss of metabolically produced heat to the environment. While this has no negative consequences in small colonies, it produces a trade-off with gas exchange in large colonies, resulting in suboptimally low nest temperatures and increased CO2 concentrations. Along with the alteration in mound architecture, the gas exchange/ventilation mechanism also changes. While mounds in the thermally appropriate savannah have a very efficient circular ventilation during the day, the ventilation in the cooler forest is a less efficient upward movement of air, with gas exchange restricted by reduced surface exchange area. These results, together with other recent findings, question entrenched ideas such as the thermosiphon-ventilation mechanism or the assumption that mounds function to dissipate internally produced heat. Models trying to explain the proximate mechanisms of mound building, or building elements, are discussed.

  11. Open circuit mouthpiece ventilation: Concise clinical review.

    PubMed

    Garuti, G; Nicolini, A; Grecchi, B; Lusuardi, M; Winck, J C; Bach, J R

    2014-01-01

    In 2013 new "mouthpiece ventilation" modes are being introduced to commercially available portable ventilators. Despite this, there is little knowledge of how to use noninvasive intermittent positive pressure ventilation (NIV) as opposed to bi-level positive airway pressure (PAP) and both have almost exclusively been reported to have been used via nasal or oro-nasal interfaces rather than via a simple mouthpiece. Non-invasive ventilation is often reported as failing because of airway secretion encumbrance, because of hypercapnia due to inadequate bi-level PAP settings, or poor interface tolerance. The latter can be caused by factors such as excessive pressure on the face from poor fit, excessive oral air leak, anxiety, claustrophobia, and patient-ventilator dys-synchrony. Thus, the interface plays a crucial role in tolerance and effectiveness. Interfaces that cover the nose and/or nose and mouth (oro-nasal) are the most commonly used but are more likely to cause skin breakdown and claustrophobia. Most associated drawbacks can be avoided by using mouthpiece NIV. Open-circuit mouthpiece NIV is being used by large populations in some centers for daytime ventilatory support and complements nocturnal NIV via "mask" interfaces for nocturnal ventilatory support. Mouthpiece NIV is also being used for sleep with the mouthpiece fixed in place by a lip-covering flange. Small 15 and 22mm angled mouthpieces and straw-type mouthpieces are the most commonly used. NIV via mouthpiece is being used as an effective alternative to ventilatory support via tracheostomy tube (TMV) and is associated with a reduced risk of pneumonias and other respiratory complications. Its use facilitates "air-stacking" to improve cough, speech, and pulmonary compliance, all of which better maintain quality of life for patients with neuromuscular diseases (NMDs) than the invasive alternatives. Considering these benefits and the new availability of mouthpiece ventilator modes, wider knowledge of this technique is now warranted. This review highlights the indications, techniques, advantages and disadvantages of mouthpiece NIV. PMID:24841239

  12. Regenerative Blower for EVA Suit Ventilation Fan

    NASA Technical Reports Server (NTRS)

    Paul, Heather; Izenson, Mike; Chen, Weibo

    2008-01-01

    Portable life support systems in future space suits will include a ventilation subsystem driven by a dedicated fan. This ventilation fan must meet challenging requirements for pressure rise, flow rate, efficiency, size, safety, and reliability. This paper describes research and development that showed the feasibility of a regenerative blower that is uniquely suited to meet these requirements. We proved feasibility through component tests, blower tests, and design analysis. Based on the requirements for the Constellation Space Suit ventilation fan, we designed the critical elements of the blower. We measured the effects of key design parameters on blower performance using separate effects tests, and used the results of these tests to design a regenerative blower that will meet the ventilation fan requirements. We assembled a proof-of-concept blower and measured its performance at low pressures that simulate a PLSS environment. We obtained head/flow performance curves over a range of operating speeds, identified the maximum efficiency point for the blower, and used these results to specify the design and operating conditions for the ventilation fan. We designed a compact motor that can drive the blower under all anticipated operating requirements and operate with high efficiency during normal operation. We identified materials for the blower that will enhance safety for operation in a lunar environment. We produced a solid model that illustrates the final design. The proof-of-concept blower produced the flow rate and pressure rise needed for the CSSS ventilation subsystem while running at 5400 rpm and consuming only 9 W of electric power and using a non-optimized, commercial motor and controller and inefficient bearings. Scaling the test results to a complete design shows that a lightweight, compact, reliable, and low power blower can meet the performance requirements for future PLSSs.

  13. Adaptive support ventilation: State of the art review

    PubMed Central

    Fernández, Jaime; Miguelena, Dayra; Mulett, Hernando; Godoy, Javier; Martinón-Torres, Federico

    2013-01-01

    Mechanical ventilation is one of the most commonly applied interventions in intensive care units. Despite its life-saving role, it can be a risky procedure for the patient if not applied appropriately. To decrease risks, new ventilator modes continue to be developed in an attempt to improve patient outcomes. Advances in ventilator modes include closed-loop systems that facilitate ventilator manipulation of variables based on measured respiratory parameters. Adaptive support ventilation (ASV) is a positive pressure mode of mechanical ventilation that is closed-loop controlled, and automatically adjust based on the patient's requirements. In order to deliver safe and appropriate patient care, clinicians need to achieve a thorough understanding of this mode, including its effects on underlying respiratory mechanics. This article will discuss ASV while emphasizing appropriate ventilator settings, their advantages and disadvantages, their particular effects on oxygenation and ventilation, and the monitoring priorities for clinicians. PMID:23833471

  14. Study of natural ventilation in buildings with large eddy simulation

    E-print Network

    Jiang, Yi, 1972-

    2002-01-01

    With the discovery of many economic, environmental, and health problems in sealed and mechanically ventilated buildings, the concept of natural ventilation has been revived. "Buildings that breathe" have become more and ...

  15. VENTILATION RESEARCH: A REVIEW OF RECENT INDOOR AIR QUALITY LITERATURE

    EPA Science Inventory

    The report gives results of a literature review, conducted to survey and summarize recent and ongoing engineering research into building ventilation, air exchange rate, pollutant distribution and dispersion, and other effects of heating, ventilation, and air-conditioning (HVAC) s...

  16. 30 CFR 77.1106 - Battery-charging stations; ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 2012-07-01 2012-07-01 false Battery-charging stations; ventilation. 77...COAL MINES Fire Protection § 77.1106 Battery-charging stations; ventilation. Battery-charging stations shall be located in...

  17. 30 CFR 77.1106 - Battery-charging stations; ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 2013-07-01 2013-07-01 false Battery-charging stations; ventilation. 77...COAL MINES Fire Protection § 77.1106 Battery-charging stations; ventilation. Battery-charging stations shall be located in...

  18. 30 CFR 77.1106 - Battery-charging stations; ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 2014-07-01 2014-07-01 false Battery-charging stations; ventilation. 77...COAL MINES Fire Protection § 77.1106 Battery-charging stations; ventilation. Battery-charging stations shall be located in...

  19. 46 CFR 38.20-10 - Ventilation-T/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...DEPARTMENT OF HOMELAND SECURITY TANK VESSELS LIQUEFIED FLAMMABLE GASES Venting and Ventilation § 38.20-10 Ventilation—T...nonpressure vessel type tanks, i.e., within the secondary barrier. (2) The space surrounding pressure-vessel type...

  20. Elective ventilation for organ donation: law, policy and public ethics

    PubMed Central

    Coggon, John

    2013-01-01

    This paper examines questions concerning elective ventilation, contextualised within English law and policy. It presents the general debate with reference both to the Exeter Protocol on elective ventilation, and the considerable developments in legal principle since the time that that protocol was declared to be unlawful. I distinguish different aspects of what might be labelled elective ventilation policies under the following four headings: ‘basic elective ventilation’; ‘epistemically complex elective ventilation’; ‘practically complex elective ventilation’; and ‘epistemically and practically complex elective ventilation’. I give a legal analysis of each. In concluding remarks on their potential practical viability, I emphasise the importance not just of ascertaining the legal and ethical acceptability of these and other forms of elective ventilation, but also of assessing their professional and political acceptability. This importance relates both to the successful implementation of the individual practices, and to guarding against possible harmful effects in the wider efforts to increase the rates of posthumous organ donation. PMID:23222143

  1. Application Study on Combined Ventilation System of Improving IAQ 

    E-print Network

    Hu, S.; Li, G.; Zhang, C.; Ye, B.

    2006-01-01

    A type of combined ventilating system is put forward in this paper. Through CFD simulation and testing of contaminant concentrations in a prototype residential room, the results demonstrate that the new ventilating system is advantageous...

  2. Study on Influencing Factors of Night Ventilation in Office Rooms 

    E-print Network

    Wang, Z.; Sun, X.

    2006-01-01

    A mathematical and physical model on night ventilation is set up. The fields of indoor air temperature, air velocity and thermal comfort are simulated using Airpak software. Some main influencing factors of night ventilation in office rooms...

  3. 30 CFR 57.14213 - Ventilation and shielding for welding.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Ventilation and shielding for welding. 57.14213 Section 57.14213 Mineral Resources...Procedures § 57.14213 Ventilation and shielding for welding. (a) Welding operations shall be shielded when performed at...

  4. 30 CFR 57.14213 - Ventilation and shielding for welding.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Ventilation and shielding for welding. 57.14213 Section 57.14213 Mineral Resources...Procedures § 57.14213 Ventilation and shielding for welding. (a) Welding operations shall be shielded when performed at...

  5. 30 CFR 56.14213 - Ventilation and shielding for welding.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Ventilation and shielding for welding. 56.14213 Section 56.14213 Mineral Resources...Procedures § 56.14213 Ventilation and shielding for welding. (a) Welding operations shall be shielded when performed at...

  6. 30 CFR 57.14213 - Ventilation and shielding for welding.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Ventilation and shielding for welding. 57.14213 Section 57.14213 Mineral Resources...Procedures § 57.14213 Ventilation and shielding for welding. (a) Welding operations shall be shielded when performed at...

  7. 30 CFR 57.14213 - Ventilation and shielding for welding.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Ventilation and shielding for welding. 57.14213 Section 57.14213 Mineral Resources...Procedures § 57.14213 Ventilation and shielding for welding. (a) Welding operations shall be shielded when performed at...

  8. 30 CFR 57.14213 - Ventilation and shielding for welding.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false Ventilation and shielding for welding. 57.14213 Section 57.14213 Mineral Resources...Procedures § 57.14213 Ventilation and shielding for welding. (a) Welding operations shall be shielded when performed at...

  9. 30 CFR 56.14213 - Ventilation and shielding for welding.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Ventilation and shielding for welding. 56.14213 Section 56.14213 Mineral Resources...Procedures § 56.14213 Ventilation and shielding for welding. (a) Welding operations shall be shielded when performed at...

  10. 30 CFR 56.14213 - Ventilation and shielding for welding.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false Ventilation and shielding for welding. 56.14213 Section 56.14213 Mineral Resources...Procedures § 56.14213 Ventilation and shielding for welding. (a) Welding operations shall be shielded when performed at...

  11. 30 CFR 56.14213 - Ventilation and shielding for welding.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Ventilation and shielding for welding. 56.14213 Section 56.14213 Mineral Resources...Procedures § 56.14213 Ventilation and shielding for welding. (a) Welding operations shall be shielded when performed at...

  12. 30 CFR 56.14213 - Ventilation and shielding for welding.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Ventilation and shielding for welding. 56.14213 Section 56.14213 Mineral Resources...Procedures § 56.14213 Ventilation and shielding for welding. (a) Welding operations shall be shielded when performed at...

  13. USE OF NATURAL VENTILATION TO CONTROL RADON IN SINGLE FAMILYDWELLINGS

    EPA Science Inventory

    The paper discusses an examination of a fundamental assumption inradon mitigation work, that natural ventilation is not veryeffective in lowering indoor radon levels in buildings. Themechanism by which ventilation acted to reduce radon levels wasconsidered to be simple dilution; ...

  14. A scale model study of displacement ventilation with chilled ceilings

    E-print Network

    Holden, Katherine J. A. (Katherine Joan Adrienne)

    1995-01-01

    Displacement ventilation is a form of air-conditioning which provides good air quality and some energy savings. The air quality is better than for a conventional mixed ventilation system. The maximum amount of cooling that ...

  15. 12. NEW YORK SIDE, HUDSON RIVER VENTILATION BUILDING IN FOREGROUND; ...

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

    12. NEW YORK SIDE, HUDSON RIVER VENTILATION BUILDING IN FOREGROUND; NEW JERSEY SIDE, HUDSON RIVEN VENTILATION BUILDING IN BACKGROUND - Holland Tunnel, Beneath Hudson River between New York & Jersey City, New York, New York County, NY

  16. 30 CFR 77.1106 - Battery-charging stations; ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 2010-07-01 2010-07-01 false Battery-charging stations; ventilation. 77...COAL MINES Fire Protection § 77.1106 Battery-charging stations; ventilation. Battery-charging stations shall be located in...

  17. 30 CFR 77.1106 - Battery-charging stations; ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 2011-07-01 2011-07-01 false Battery-charging stations; ventilation. 77...COAL MINES Fire Protection § 77.1106 Battery-charging stations; ventilation. Battery-charging stations shall be located in...

  18. Modeling buoyancy-driven airflow in ventilation shafts

    E-print Network

    Ray, Stephen D. (Stephen Douglas)

    2012-01-01

    Naturally ventilated buildings can significantly reduce the required energy for cooling and ventilating buildings by drawing in outdoor air using non-mechanical forces. Buoyancy-driven systems are common in naturally ...

  19. 2. BRICK END ELEVATION WITH X VENTILATORS, REDPAINTED GABLE WITH ...

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

    2. BRICK END ELEVATION WITH X VENTILATORS, RED-PAINTED GABLE WITH WHITE STARS AND A DOORWAY HOOD. ALSO SHOWS PORTION OF REAR ELEVATION WITH X VENTILATORS - Decorated Red Barn (1852), State Route 100 vicinity, Pottstown, Montgomery County, PA

  20. Ways of improving economy and reliability of mine ventilation

    SciTech Connect

    N.N. Petrov; N.A. Popov

    2004-09-01

    It is established that mine ventilation by main fans operating at maximum capacity results in higher power consumption. The ways are proposed for reduction in the effective power consumption by ventilation and improvement of mining operation safety.

  1. Design of a Natural Ventilation System in the Dunhuang Museum 

    E-print Network

    Zhang, Y.; Guan, W.

    2006-01-01

    that also meets architectural standards. Natural ventilation design methods are presented in this paper. A natural ventilation system is designed in the DunHuang museum. Thermal dynamic simulation and CFD simulation were analyzed in the exhibition hall...

  2. Natural ventilation : design for suburban houses in Thailand

    E-print Network

    Tantasavasdi, Chalermwat, 1971-

    1998-01-01

    Natural Ventilation is the most effective passive cooling design strategy for architecture in hot and humid climates. In Thailand, natural ventilation has been the most essential element in the vernacular architecture such ...

  3. Indoor Air Quality: Is Increased Ventilation the Answer?

    ERIC Educational Resources Information Center

    Hansen, Shirley

    1989-01-01

    Explains how indoor air quality is affected by pollutants in the air and also by temperature, humidity, and ventilation. Increased ventilation alone seldom solves the "sick building syndrome." Lists ways to improve indoor air quality and optimize energy efficiency. (MLF)

  4. Noninvasive Ventilation for the Emergency Physician.

    PubMed

    Allison, Michael G; Winters, Michael E

    2016-02-01

    Noninvasive ventilation (NIV) improves oxygenation and ventilation, prevents endotracheal intubation, and decreases the mortality rate in select patients with acute respiratory failure. Although NIV is used commonly for acute exacerbations of chronic obstructive pulmonary disease and acute cardiogenic pulmonary edema, there are emerging indications for its use in the emergency department. Emergency physicians must be knowledgeable regarding the indications and contraindications for NIV in emergency department patients with acute respiratory failure as well as the means of initiating it and monitoring patients who are receiving it. PMID:26614241

  5. Ventilation Requirements in Hot Humid Climates 

    E-print Network

    Walker, I. S.; Sherman, M. H.

    2006-01-01

    stream_source_info ESL-HH-06-07-04.pdf.txt stream_content_type text/plain stream_size 28193 Content-Encoding UTF-8 stream_name ESL-HH-06-07-04.pdf.txt Content-Type text/plain; charset=UTF-8 VENTILATION REQUIREMENTS... IN HOT, HUMID CLIMATES I.S. Walker M. H. Sherman Staff Scientist Senior Scientist Lawrence Berkeley National Laboratory Berkeley CA ABSTRACT In 2003 ASHRAE approved the nation’s first residential ventilation standard, ASHRAE Standard...

  6. Intermodule ventilation studies for the Space Station

    NASA Technical Reports Server (NTRS)

    Davis, Roy G.; Reuter, James L.

    1987-01-01

    This paper examines the ability of the Space Station intermodule ventilation system to maintain centralized control of CO2 removal and O2 supply. The resulting concentration gradients that will arise are calculated by assuming steady state, ideal gas, isothermal conditions, and perfect mixing of air within and between the pressurized elements. In order to estimate the degree of mixing actually obtained for a given ventilation scheme, a program has been developed based on a potential flow solution technique. Preliminary results from this study indicate that substantial short circuiting and recirculation air flow patterns could arise if a simple duct and diffuser air exchange method at the docking port interface were employed.

  7. Preoperational test report, recirculation ventilation systems

    SciTech Connect

    Clifton, F.T.

    1997-11-11

    This represents a preoperational test report for Recirculation Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides vapor space cooling of tanks AY1O1, AY102, AZ1O1, AZ102 and supports the ability to exhaust air from each tank. Each system consists of a valved piping loop, a fan, condenser, and moisture separator; equipment is located inside each respective tank farm in its own hardened building. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  8. Measurement of continuous distributions of ventilation-perfusion ratios - Theory

    NASA Technical Reports Server (NTRS)

    Wagner, P. D.; Saltzman, H. A.; West, J. B.

    1974-01-01

    The resolution of the technique considered is sufficient to describe smooth distributions containing blood flow to unventilated regions (shunt), ventilation to unperfused regions (dead space), and up to three additional modes over the range of finite ventilation-perfusion ratios. In particular, areas whose ventilation-perfusion ratios are low can be separated from unventilated regions and those whose ventilation-perfusion ratios are high can similarly be distinguished from unperfused areas.

  9. Pneumococcal Conjugate Vaccine (PCV7)

    MedlinePLUS

    What is pneumococcal disease?Infection with Streptococcus pneumoniae bacteria can make children very sick. It causes blood infections, pneumonia, and bacterial meningitis, mostly in young children. (Meningitis is an infection ...

  10. 30 CFR 36.45 - Quantity of ventilating air.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Quantity of ventilating air. 36.45 Section 36... TRANSPORTATION EQUIPMENT Test Requirements § 36.45 Quantity of ventilating air. (a) Results of the engine tests shall be used to calculate ventilation (cubic feet of air per minute) that shall be supplied by...

  11. 46 CFR 78.47-53 - Automatic ventilation dampers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Automatic ventilation dampers. 78.47-53 Section 78.47-53... Fire and Emergency Equipment, Etc. § 78.47-53 Automatic ventilation dampers. (a) The manual operating positions for automatic fire dampers in ventilation ducts passing through main vertical zone bulkheads...

  12. 46 CFR 78.47-53 - Automatic ventilation dampers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 3 2011-10-01 2011-10-01 false Automatic ventilation dampers. 78.47-53 Section 78.47-53... Fire and Emergency Equipment, Etc. § 78.47-53 Automatic ventilation dampers. (a) The manual operating positions for automatic fire dampers in ventilation ducts passing through main vertical zone bulkheads...

  13. 30 CFR 75.372 - Mine ventilation map.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Mine ventilation map. 75.372 Section 75.372... MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.372 Mine ventilation map. (a)(1) At...-date map of the mine drawn to a scale of not less than 100 nor more than 500 feet to the inch....

  14. 30 CFR 77.1106 - Battery-charging stations; ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Battery-charging stations; ventilation. 77.1106... COAL MINES Fire Protection § 77.1106 Battery-charging stations; ventilation. Battery-charging stations shall be located in well-ventilated areas. Battery-charging stations shall be equipped with...

  15. 30 CFR 77.1106 - Battery-charging stations; ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Battery-charging stations; ventilation. 77.1106... COAL MINES Fire Protection § 77.1106 Battery-charging stations; ventilation. Battery-charging stations shall be located in well-ventilated areas. Battery-charging stations shall be equipped with...

  16. 30 CFR 77.1106 - Battery-charging stations; ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Battery-charging stations; ventilation. 77.1106... COAL MINES Fire Protection § 77.1106 Battery-charging stations; ventilation. Battery-charging stations shall be located in well-ventilated areas. Battery-charging stations shall be equipped with...

  17. 30 CFR 77.1106 - Battery-charging stations; ventilation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Battery-charging stations; ventilation. 77.1106... COAL MINES Fire Protection § 77.1106 Battery-charging stations; ventilation. Battery-charging stations shall be located in well-ventilated areas. Battery-charging stations shall be equipped with...

  18. 30 CFR 77.1106 - Battery-charging stations; ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Battery-charging stations; ventilation. 77.1106... COAL MINES Fire Protection § 77.1106 Battery-charging stations; ventilation. Battery-charging stations shall be located in well-ventilated areas. Battery-charging stations shall be equipped with...

  19. 24 CFR 3280.103 - Light and ventilation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... URBAN DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Planning Considerations § 3280.103.... (b) Whole-house ventilation. Each manufactured home must be provided with whole-house ventilation... permitted to be provided with automatic timers or humidistats. (5) A whole-house ventilation label must...

  20. 30 CFR 75.372 - Mine ventilation map.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Mine ventilation map. 75.372 Section 75.372 Mineral...Ventilation § 75.372 Mine ventilation map. (a)(1) At intervals not exceeding...district manager 3 copies of an up-to-date map of the mine drawn to a scale of not...