Desestratificação de reservatórios por meio de aeração artificial / Reservoir destratification via artificial aeration

RESUMO No presente trabalho, avaliou-se em escala de laboratório e por meio de modelagem matemática o processo de desestratificação da coluna d'água usando aeração por ar difuso. Foram identificados dois padrões de escoamento: um regime de pluma, no qual o escoamento induzido pelas bolhas penetra na interface entre as duas camadas de diferentes densidades e ascende à superfície da água; e um regime de fonte, no qual o escoamento penetra parcialmente na interface e colapsa para formar uma camada de densidade intermediária. Os resultados experimentais mostraram que o regime de pluma promove mistura mais rápida da camada superior (epilímnio) do que o regime de fonte. Os tempos de mistura da camada inferior (hipolímnio), entretanto, foram praticamente os mesmos para os dois regimes. Após o ajuste de parâmetros do modelo que descreve a incorporação do fluido ambiente na pluma e na fonte, pôde-se simular o processo de desestratificação da coluna d'água com boa aderência aos dados experimentais obtidos nesta pesquisa e em trabalhos anteriores. Por fim, o modelo validado foi aplicado para a simulação do impacto de diferentes vazões de ar na evolução temporal do processo de desestratificação de reservatórios (escala real), sendo discutidos os custos com energia elétrica para bombeamento e as possíveis implicações na qualidade da água desses corpos hídricos.

ABSTRACT In the present work, the destratification process of water column using diffused-aeration was evaluated at laboratorial scale by mathematical modelling. Two flow patterns were identified, a plume regime, in which the bubble-induced flow penetrates the interface (density gradient) and rises to the water surface, and a fountain regime, in which the flow partially penetrates the interface and collapses to form an intermediate-density layer. The experimental results showed that the plume regime promotes a faster mixing of the upper layer (epilimnion) than the fountain regime. However, the mixing times of the lower layer (hypolimnion) were practically the same for both regimes. After adjusting the parameters that describe the entrainment of the ambient fluid into the plume and fountain, it was possible to simulate the process of water column destratification with good adherence to the experimental data obtained in this research and previous studies. Finally, the validated model was applied to simulate the impact of different airflow rates on the reservoir destratification process' (real scale) time evolution, and the possible implications for the water quality of these water bodies were discussed.

Effects of simethicone on the quality of video capsule endoscopy examination / 中华消化杂志

Objective To investigate the effects of simethicone on the quality of video capsule endoscopy (VCE) examination.Methods A prospective study was performed in 90 patients received VCE examination from February 2010 to October 2014.The randomized table was set according to different dosage of simethicone the patients received,by which patients were divided into three groups.Group 1 (35 cases) received 15 mL simethicone,group 2 (30 cases) received 30 mL simethicone and control group (25 cases) received no simethicone.The small intestinal visualization quality of VCE was scored by segments.Segment A was proximal small intestine (one hour after VCE passing pylorus).Segment B was distal small intestine (one hour before VCE passing ileocecal valve).Segment A and B were scored according to the air bubbles and degree of cleanliness.Gastric transit time,small bowel transit time and VCE completion rate were recorded.Student's t test,Mann Whitney rank sum test and chi square test were performed for statistical analysis.Results The average scores of segment A of group 1,group 2 and control group were 0.58,0.33 and 1.67,respectively,and the average socres of segment B were 0.25,0.00 and 1.17,respectively.The lesion detection rates of group 1,group 2 and control group were 68.6％ (24/35),80.0％ (24/30) and 52.0％ (13/25),respectively,and the differences was statistically significant (x2 =8.238,P=0.016).The detection rate of group 2 was significantly higher than those of group 1 and control group (x2 =7.354 and 9.349,P=0.034 and 0.005).The detection rates of small intestinal erosion of group 1,group 2 and control group were 22.9％ (8/35),70.0％ (21/30) and 32.0％ (8/25),respectively,and the differences was statistically significant (x2=8.714,P=0.013).The detection rate of group 2 was significantly higher than those of group 1 and control group (x2 =10.600 and 7.380,P=0.005 and 0.025).There was no statistically significant difference in the detection rates of ulcer,vascular malformation and protrusion among the three groups (all P＞0.05).The detection rates of lesions＜0.5 cm of group 1,group 2 and control group were 37.1％ (13/35),66.7％ (20/30) and 32.0％ (8/25),respectively,and the differences was statistically significant (x2 =8.242,P=0.016).The detection rate of group 2 was significantly higher than those of group 1 and control group (x2 =9.250 and 7.842,P =0.011 and 0.017).Conclusion Oral adminstration of 30 mL simethicone could obviously decrease air bubbles in small intestine,and increase lesion detection rate of VCE.

Tamanho de bolhas de ar formadas por difusores não porosos na água / Size of air bubbles formed from non-porous diffusers in water

Neste estudo foram realizados experimentos para investigar o tamanho de bolhas de ar formadas a partir de difusores não porosos em um tanque de água. O tamanho das bolhas individuais e o diâmetro de Sauter foram avaliados usando uma técnica de processamento de imagens. Os resultados confirmam que a vazão de ar e o diâmetro do orifício são parâmetros importantes que controlam a distribuição do tamanho das bolhas e o diâmetro de Sauter. Análise dimensional é realizada para fornecer uma relação adimensional geral para predição do diâmetro de Sauter (usando uma escala de comprimento adequada, baseada na vazão de ar) e o número de Reynolds na saída do orifício. Essa relação apresenta bom ajuste aos dados experimentais obtidos neste estudo e a partir de investigações anteriores disponíveis na literatura, incluindo também experimentos com múltiplos orifícios. Finalmente, são apresentadas aplicações potenciais da relação adimensional obtida.

Experiments are conducted in this study to investigate the size of air bubbles formed from orifice diffusers in a water tank. The size of individual bubbles and the Sauter diameter are evaluated using an image processing technique. The results confirm that the air flow rate and the nozzle diameter are important parameters controlling the bubble size distribution and Sauter diameter. Dimensional analysis is performed to provide a general dimensionless relationship for the bubble Sauter diameter by using an appropriate length scale, which is based on the air flow rate, and the Reynolds number at the nozzle exit. This relationship fits well the experimental data from this study and previous investigations available in the literature, also including experiments for multiple orifice diffusers. Finally, potential applications of the dimensionless relationship obtained here are presented.

Evaluation of the role of contrast enhanced ultrasound in treatment of ultrasound guided high intensity focused ultrasound ablation for uterine fibroids / 重庆医学

Objective To evaluate the role of contrast enhanced ultrasound in treatment of ultrasound guided high intensity fo‐cused ultrasound ablation for uterine fibroids .Methods Forty eight women with uterine fibroids were allocated into contrast en‐hanced group(25cases ,42fibroids) and non contrast enhanced group(23 cases ,35 fibroids) .The average volume of fibroids and the non perfused volume and the fractional ablation and adverse effects between the tow groups were compared .Results Non perfused volume was observed in all fibroids of the two groups after high intensity focused ultrasound ablation through sulphur hexafluoride micro bubbles .The average non perfused volume was 19 .5(18 .2)cm3 and 22 .5(14 .5)cm3 ,fractional ablation was (78 ± 18)% and (87 ± 13)% of the uterus immediately after HIFU respectively .The average non perfused volume was 18 .6(18 .2)cm3 and 19 .5 (18 .7)cm3 ,fractional ablation was (85 .7 ± 15 .2)% and (87 .6 ± 8 .0)% of the uterus two days after HIFU .There was no signifi‐cant difference was observed in average non perfused volume and the fractional ablation between the two groups(P>0 .05) .During HIFU procedure ,more patients in non contrast enhanced group complained sacral pain than those in contrast enhanced group(P<0 .05) .Conclusion Contrast enhanced ultrasound is an accurate method in assessing the treatment effect of HIFU and could be safely used during HIFU treatment for uterine fibroids ,shorten therapy time ,and decrease side reaction .

Transferência de massa em sistemas de aeração por jatos bifásicos / Mass transfer in two-phase jet aeration systems

A injeção de misturas de ar e água na forma de jatos bifásicos é bastante usada para a aeração artificial em tanques e corpos hídricos. No presente trabalho, foram realizados experimentos para investigar a transferência de massa induzida por estes jatos em um tanque de aeração. Os resultados forneceram eficiências de transferência de oxigênio padrão variando entre aproximadamente 5 e 9%. Combinando-se os dados obtidos nesta pesquisa com os disponíveis na literatura, foram geradas correlações adimensionais para o coeficiente de transferência de massa em função da fração volumétrica de ar e do número de Froude densimétrico. Finalmente, os resultados foram aplicados a situações práticas envolvendo sistemas de aeração por jatos bifásicos.

The injection of air-water mixtures through two-phase jets is widely used for artificial aeration in tanks and water bodies. In this study, experiments were conducted to investigate mass transfer induced by such jets in an aeration tank. The results provided standard oxygen transfer efficiencies ranging from about 5 to 9%. Combining the results obtained here with those from previous investigations allowed to generate dimensionless correlations for the mass transfer coefficient as a function of the gas volume fraction and the densimetric Froude number. Finally, the results were applied to practical situations involving two-phase jet aeration systems.

Research in effect of modified drug preparation method on reduction of air bubble formation in infusion bags / 中国实用护理杂志

Objective To investigate a new method to reduce air bubbles formation during drug preparation. Methods 200 portions of drugs from hospital pharmacy were randomly divided into the control group and the experimental group with 100 portions in each group. In the experimental group, the infusion bags were put flat on the desktop, the needles pierced into the bags parallel, and immersed in the liquid inside. In the control group, the infusion bags were put perpendicular to the desktop, the needle pierced into the bags vertically, the needles do not immersed in the liquid. Air bubble formation in the infusion bags was compared between the two groups. Results Air bubble formation in the experimental group was significantly less than that of the control group. Conclusions The modified new method for drug preparation can reduce the formation of air bubbles.

Turbulência induzida por jatos bifásicos do tipo gás-líquido em tanques de aeração / Turbulence induced by two-phase gas-liquid jets in aeration tanks

Jatos bifásicos do tipo gás-líquido são bastante usados nas engenharias sanitária e ambiental para fins de aeração artificial e mistura turbulenta. O presente trabalho investiga a turbulência gerada por meio desses jatos em um tanque de água, utilizando velocimetria por imagem de partículas. As condições experimentais incluíram jatos bifásicos com frações volumétricas de ar de até 70 por cento e números de Reynolds variando entre 10.600 e 17.700. Os resultados dos ensaios indicaram que a fração volumétrica de ar afeta consideravelmente as propriedades turbulentas da fase líquida, enquanto o número de Reynolds apresenta efeito secundário. Correlações adimensionais foram então obtidas para expressar a energia cinética turbulenta e a taxa de dissipação de energia em função desses dois parâmetros. Finalmente, são apresentadas possíveis aplicações dos resultados deste trabalho.

Two-phase gas-liquid jets are widely used in the sanitary and environmental engineering field for artificial aeration and turbulent mixing. The present work investigates the turbulence generated by these jets in a water tank, using particle image velocimetry. The experimental conditions included two-phase jets with gas volume fractions of up to 70 percent and Reynolds numbers ranging from 10,600 to 17,700. The results indicated that the gas volume fraction affects significantly the turbulent properties of the liquid phase, while the Reynolds number presents a secondary effect. Dimensionless correlations were then obtained to express the turbulent kinetic energy and dissipation rate as a function of these two parameters. Finally, possible applications of the results obtained in this work are presented.

Coprotiella venezuelensis: a new record of cleistothecia genus of the ascomycetes in the world

A new record, Coprotiella venezuelensis was isolate on rhinoce-rosdung collected at south park Maracaibo zoo in Zulia State, Venezuela. The genus is compared with Coprotus and C.gongylospora having ascospores possessing De Bary bubbles.

Un nuevo registro, Coprotiella venezuelensis, fue aislado en heces de rinocerontes, colectados en el Parque Sur Zoológico en el estado Zulia, Venezuela. El género es comparado con Coprotus y C. gongylospora presentando ascósporas con burbujas de Bary.

Spontaneous, Fulminant Gas Gangrene Caused by Klebsiella Pneumoniae: An Unrecognized Small Air Bubbles in the Left Femoral, External and Common Iliac Vein, and Inferior Vena Cava: A case report / 대한마취과학회지

Fulminant gas gangrene is a rare condition, usually associated with contaminated traumatic injuries. It carries a high rate of mortality and morbidity. Also, a number of studies have implicated non-traumatic gas gangrene, associated mostly with underlying diseases that cause immunodeficiency. We report a non-traumatic fatal case of Klebsiella pneumoniae gas gangrene with small air bubbles in the left external and common iliac vein, and inferior vena cava in a previously healthy male. We would like to recommend you do not use nitrous oxide in case of gas gangrene, because it can aggravate pulmonary air embolism.

The Incidence and Severity of Venous Air Embolism Determined by Transesophaseal Echocardiography in Hepatic Resection Using a Cavitron Ultrasonic Surgical Aspirator Dong / 대한마취과학회지

BACKGROUND: A new technique resecting the hepatic parenchyma without inflow occlusion using a Cavitron Ultrasonic Surgical Aspirator (CUSA(R) ) reduces intraoperative blood loss and perioperative morbidity. This study was designed to identify the incidence and severity of venous air embolism (VAE) using transesophaseal echocardiography (TEE) in hepatic resection using CUSA(R) . METHODS: Forty patients undergoing hepatic resection using CUSA(R) of ASA class 1 and 2 were selected. After insertion of an epidural catheter for postoperative analgesia, all patients were anesthetized with sevoflurane in 50% air/O2. After the induction of anesthesia, A TEE probe was inserted into the esophagus. Blood pressure, heart rate, central venous pressure, end tidal CO2, and arterial carbon dioxide tension were recorded after induction, and during and after hepatic resection. During hepatic resection, an anesthesiologist evaluated the degree of VAE by transesophageal echocardiography in the 4-chamber view. RESULTS: The mean time of using CUSA(R) was 65.3 +/- 24.4 minutes. Of 40 patients, 9 had VAE grade I, 14 grade II, 14 grade III, and 3 grade IV. However, no significant difference was observed in hemodynamics or PaCO2 after induction, or during or after hepatic resection. The mean amount of blood loss was 887.0 ml +/- 598.8 ml and the mean transfused amount was 123.1 +/- 351.3 ml. CONCLUSIONS: All patients showed air embolism during hepatic resection with CUSA(R) . Serious complications associated with air embolism would occur in patients with an undiagnosed intracardiac right to left shunt. Therefore, meticulous monitoring by transesophageal echocardiography might be recommended in hepatic resection with CUSA(R) .

Protective Effects of Viscoelastic Substances on air Bubble Damage During Phacoemulsification

PURPOSE: To determine whether viscoelastic materials are effective to protect the corneal endothelium from air bubble damage. METHODS: Human eye bank (n=12) and rabbit (n=22) eyes underwent a standardized phacoemulsification procedure with or without viscoelastic material [1% sodium hyaluronate (Healon(R)), 1.4% sodium hyaluronate (Healon GV(R)), 3% sodium hyaluronate with 4% chondroitin sulfate (Viscoat(R))]. The integrity of the endothelium was examined after the procedure with F-actin staining and scanning electron microscopy (SEM). RESULTS: In the phacoemulsification experiment without viscoelastic material, with Healon, and with Healon GV, the endothelium of both human and rabbit corneas had many areas of cell loss in a pattern consistent with air bubble damage. But with Viscoat, endothelial cells remained intact. CONCLUSIONS: We found that Viscoat was effective to protect the endothelium from air bubble damage. Viscoat seems to protect the endothelium by acting as a physical barrier.

Effects of two fluorides on the fluoride content in the deciduous teeth enamel:A clinical study / 实用口腔医学杂志

Objective:To determine the fluorine content in enamel before and after besmearing fluoride varnishes or fluorinated bubbles. Methods:Thirty patients whose deciduous central incisors will be extracted were divided into group a and b randomly. For the same patient, a pair of mandibular deciduous central incisor were chosen. For group a: one tooth was removed, and the other one besmeared with fluoride varnishes and removed 24 h later. For group b: one tooth was removed, and the other one besmeared with fluorinated bubbles and removed 24 h later. The fluorine contents in the enamel of every tooth were determined by neutron activation method and analyzed statistically. Results:For group a: the fluorine content in the experimental group was (142.78?42.25) ?g/g, and that in the control group was(119.62?38.62) ?g/g. For group b: (162.36?31.36) ?g/g and (126.56?38.42) ?g/g respectively. The fluorine content in the enamel of tooth besmeared with fluoride varnishes or fluorinated bubbles was higher than that in the control group(P