Performance evaluation of ventilation radiators

A ventilation radiator is a combined ventilation and heat emission unit currently of interest due to its potential for increasing energy efficiency in exhaust ventilated buildings with warm water heating. This paper presents results of performance tests of several ventilation radiator models conducted under controlled laboratory conditions.   The purpose of the study was to validate results achieved by Computational Fluid Dynamics (CFD) in an earlier study and indentify possible improvements in the performance of such systems. The main focus was on heat transfer from internal convection fins, but comfort and health aspects related to ventilation rates and air temperatures were also considered.   The general results from the CFD simulations were confirmed; the heat output of ventilation radiators may be improved by at least 20 % without sacrificing ventilation efficiency or thermal comfort.   Improved thermal efficiency of ventilation radiators allows a lower supply water temperature and energy savings both for heating up and distribution of warm water in heat pumps or district heating systems. A secondary benefit is that a high ventilation rate can be maintained all year around without risk for cold draught.

Winning the Accreditation Game: The Library as Key Player and Hidden Gold Mine

Libraries are a central hub of information resources supporting college and university curricula. Several library strategies, cross-campus collaborations, and philosophical considerations of electronic and print offerings led to successful accreditations in business and engineering programs.

Air velocity and exposure time to ventilation affect body surface and rectal temperature of broiler chickens

Increasing air movement over poultry by using fans (ventilation) has become an accepted means of reducing environmental heat stress over the last several years. The purpose of this study was to evaluate the effect of air velocity and exposure time to ventilation on body surface and rectal temperature of broiler chickens. Male broiler chickens aged 36-42 days were placed in individual wire cages and exposed to five different air velocities (5.7, 4.2, 3.1, 2.4, or 1.8 m/sec). Throughout the experiment head, back, leg, and rectal temperatures were monitored every 10 min during a 30-min period for each air velocity. The data showed that exposure time to the wind affected (P<.05) leg and body temperature, with a rapid reduction being observed during the first 10 min. There was a reduction in leg temperature with air velocity of 2 m/sec; however, air velocity lower than 4.5 m/sec was not effective in decreasing head and back temperature. The results suggest that air velocity of 2 m/sec, in air temperature of 29 degrees C, improves heat loss in the birds. The data also indicate that exposure time to ventilation seems to be a critical point in the maintenance of bird thermal homeostasis.

Anesthetic induction with guaifenesin and propofol in adult horses

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influence of respiratory biofeedback associated to re-expansive ventilation patterns in individuals with functional mouth breathing

Objectives: Assess the effect of re-expansive respiratory patterns associated to respiratory biofeedback (RBF) on pulmonary function, respiratory muscle strength and habits in individuals with functional mouth breathing (FMB).Methods: Sixty children with FMB were divided into experimental and control groups. The experimental group was submitted to 15 sessions of re-expansive respiratory patterns associated to RBF (biofeedback pletsmovent; MICROHARD (R) V1.0), which provided biofeedback of the thoracic and abdominal movements. The control group was submitted to 15 sessions using biofeedback alone. Spirometry, maximum static respiratory pressure measurements and questions regarding habits (answered by parents/guardians) were carried out before and after therapy. The Student's t-test for paired data and non-parametric tests were employed for statistical analysis at a 5% Level of significance.Results: Significant changes were found in forced vital. capacity, Tiffeneau index scores, maximum expiratory pressure, maximum inspiratory pressure and habits assessed in FMB with the use of RBF associated to the re-expansive patterns. No significant differences were found comparing the experimental and control groups.Conclusions: The results allow the conclusion that RBF associated to re-expansive patterns improves forced vital capacity, Tiffeneau index scores, respiratory muscle strength and habits in FMB and can therefore be used as a form of therapy for such individuals. (C) 2008 Elsevier B.V. All rights reserved.

Evaluation of laryngeal mask as an alternative to endotracheal intubation in cats anesthetized under spontaneous or controlled ventilation

Objective To compare the cardiorespiratory effects and incidence of gastroesophageal reflux with the use of a laryngeal mask airway (LMA) or endotracheal tube (ET) in anesthetized cats during spontaneous (SV) or controlled ventilation (CV).Study design Prospective randomized experimental trial.Animals Thirty-two adult crossbred cats, weighing 2.7 +/- 0.4 kg.Methods the cats were sedated with intramuscular (IM) methotrimeprazine (0.5 mg kg(-1)) and buprenorphine (0.005 mg kg(-1)), followed 30 minutes later by induction of anesthesia with intravenous (IV) thiopental (12.5-20 mg kg(-1)). An ET was used in 16 cats and an LMA in the remaining 16 animals. Anesthesia was maintained with 0.5 minimum alveolar concentration (0.6%) of halothane in oxygen using a Mapleson D breathing system. Cats in both groups were further divided into two equal groups (n = 8), undergoing either SV or CV. Neuromuscular blockade with pancuronium (0.06 mg kg(-1)) was used to facilitate CV. Heart and respiratory rates, direct arterial blood pressure, capnometry (PE'CO2) and arterial blood gases were measured. Gastric reflux and possible aspiration was investigated by intragastric administration of 5 mL of radiographic contrast immediately after induction of anesthesia. Cervical and thoracic radiographs were taken at the end of anesthesia. Data were analyzed using ANOVA followed by Student-Newman-Keuls, Kruskal-Wallis or Friedman test where appropriate.Results Values for PaCO2 and PE'CO2 were higher in spontaneously breathing cats with the LMA when compared with other groups. Values of PaO2 and hemoglobin oxygen saturation did not differ between groups. Gastroesophageal reflux occurred in four of eight and two of eight cats undergoing CV with ET or LMA, respectively. There was no tracheal or pulmonary aspiration in any cases.Conclusions and clinical relevance the use of an LMA may be used as an alternative to endotracheal intubation in anesthetized cats. Although aspiration was not observed, gastric reflux may occur in mechanically ventilated animals.

High-frequency oscillatory ventilation attenuates oxidative lung injury in a rabbit model of acute lung injury

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Biomarkers for oxidative stress in acute lung injury induced in rabbits submitted to different strategies of mechanical ventilation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

High-Frequency Oscillatory Ventilation Associated With Inhaled Nitric Oxide Compared to Pressure-Controlled Assist/Control Ventilation and Inhaled Nitric Oxide in Children: Randomized, Non-Blinded, Crossover Study

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Comparison between intermittent mandatory ventilation and synchronized intermittent mandatory ventilation with pressure support in children

Objective: To compare intermittent mandatory ventilation (IMV) with synchronized intermittent mandatory ventilation plus pressure support (SIMV+PS) in terms of time on mechanical ventilation, duration of weaning and length of stay in a pediatric intensive care unit (PICU).Methods: This was a randomized clinical trial that enrolled children aged 28 days to 4 years who were admitted to a PICU between October of 2005 and June of 2007 and put on mechanical ventilation (MV) for more than 48 hours. These patients were allocated to one of two groups by drawing lots: IMV group (IMVG; n = 35) and SIMV+PS group (SIMVG; n = 35). Children were excluded if they had undergone tracheotomy or had chronic respiratory diseases. Data on oxygenation and ventilation were recorded at admission and at the start of weaning.Results: There were no statistical differences between the groups in terms of age, sex, indication for MV, PRISM score, Comfort scale, use of sedatives or ventilation and oxygenation parameters. The median time on MV was 5 days for both groups (p = 0.120). There were also no statistical differences between the two groups for duration of weaning [IMVG: 1 day (1-6) vs. SIMVG: 1 day (1-6); p = 0.262] or length of hospital stay [IMVG: 8 days (2-22) vs. SIMVG: 6 days (3-20); p = 0.113].Conclusion: Among the children studied here, there was no statistically significant difference between IMV and SIMV+ PS in terms of time on MV, duration of weaning or time spent in the PICU.ClinicalTrials.govID: NCT00549809.