Search results for: liquid aspiration
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 2017

Search results for: liquid aspiration

2017 A Computational Analysis of Gas Jet Flow Effects on Liquid Aspiration in the Collison Nebulizer

Authors: James Q. Feng

Abstract:

Pneumatic nebulizers (as variations based on the Collison nebulizer) have been widely used for producing fine aerosol droplets from a liquid material. As qualitatively described by many authors, the basic working principle of those nebulizers involves utilization of the negative pressure associated with an expanding gas jet to syphon liquid into the jet stream, then to blow and shear into liquid sheets, filaments, and eventually droplets. But detailed quantitative analysis based on fluid mechanics theory has been lacking in the literature. The purpose of present work is to investigate the nature of negative pressure distribution associated with compressible gas jet flow in the Collison nebulizer by a computational fluid dynamics (CFD) analysis, using an OpenFOAM® compressible flow solver. The value of the negative pressure associated with a gas jet flow is examined by varying geometric parameters of the jet expansion channel adjacent to the jet orifice outlet. Such an analysis can provide valuable insights into fundamental mechanisms in liquid aspiration process, helpful for effective design of the pneumatic atomizer in the Aerosol Jet® direct-write system for micro-feature, high-aspect-ratio material deposition in additive manufacturing.

Keywords: collison nebulizer, compressible gas jet flow, liquid aspiration, pneumatic atomization

Procedia PDF Downloads 133
2016 The Usefulness and Limitations of Manual Aspiration Immediately after Pneumothorax Complicating Percutaneous CT Guided Lung Biopsies: A Retrospective 9-Year Review from a Large Tertiary Centre

Authors: Niall Fennessy, Charlotte Yin, Vineet Gorolay, Michael Chan, Ilias Drivas

Abstract:

Background: The aim of this study was to evaluate the effect of manual aspiration of air from the pleural cavity in mitigating the need for chest drain placement after a CT-guided lung biopsy. Method: This is a single institution retrospective review of CT-guided lung biopsies performed on 799 patients between September 2013 and May 2021 in a major tertiary hospital. Percutaneous manual aspiration of air was performed in 104/306 patients (34%) with pneumothoraxes as a preventative measure. Simple and multivariate analysis was performed to identify independent risk factors (modifiable and nonmodifiable) for the success of manual aspiration in mitigating the need for chest drain insertion. Results: The overall incidence of pneumothorax was 37% (295/799). Chest drains were inserted for 81/295 (27%) of the pneumothoraxes, representing 81/799 (10%) of all CT-guided lung biopsies. Of patients with pneumothoraces, 104 (36%) underwent percutaneous aspiration via either the coaxial guide needle or an 18 or 20G intravenous catheter attached to a three-way stopcock and syringe. Amongst this group, 13 patients (13%) subsequently required chest drain insertion. The success of percutaneous aspiration in avoiding subsequent pleural drain insertion decreased with aspiration volume >500mL, radial pneumothorax depth >3cm, increased subpleural depth of the lesion, and the presence of background emphysema.

Keywords: computed tomography, lung biopsy, pneumothorax, manual aspiration, chest drainage

Procedia PDF Downloads 145
2015 The French, the Yoruba, and the H-Thing: Sharing and Realising Same Phenomenon Differently

Authors: Rose-Juliet Anyanwu

Abstract:

The principal objective of this paper is to investigate whether some sort of phonological processes, such as elision, aspiration, glottalisation, and hardening can be used to account for the behaviour of the glottal fricative (or approximant, as the case may be) ‘h’ in both French and Yoruba. French and Yoruba speakers generally tend to say, for instance ‘ockey’ and ‘amburger’, instead of ‘hockey’ and ‘hamburger’, respectively. Whereas the Yoruba conversely say, for instance ‘hadd’ for ‘add’, ‘heat’ for ‘eat’ on the one hand and ‘ard’ for ‘hard’, ‘eat’ for ‘heat’ on the other hand, on a similar note, it is not quite clear whether the French, however, if not at least in rare instances, would tend to force themselves to pronounce (in any form whatsoever) the h-sound. Recorded sentences containing h-initial as well as vowel-initial words will be used for the investigation. The present paper is meant to contribute to work on aspiration, compensation, elision, and glottalisation, as well as hardening.

Keywords: aspiration, compensation, glottalisation, hardening

Procedia PDF Downloads 136
2014 Improving Patient Outcomes for Aspiration Pneumonia

Authors: Mary Farrell, Maria Soubra, Sandra Vega, Dorothy Kakraba, Joanne Fontanilla, Moira Kendra, Danielle Tonzola, Stephanie Chiu

Abstract:

Pneumonia is the most common infectious cause of hospitalizations in the United States, with more than one million admissions annually and costs of $10 billion every year, making it the 8th leading cause of death. Aspiration pneumonia is an aggressive type of pneumonia that results from inhalation of oropharyngeal secretions and/or gastric contents and is preventable. The authors hypothesized that an evidence-based aspiration pneumonia clinical care pathway could reduce 30-day hospital readmissions and mortality rates, while improving the overall care of patients. We conducted a retrospective chart review on 979 patients discharged with aspiration pneumonia from January 2021 to December 2022 at Overlook Medical Center. The authors identified patients who were coded with aspiration pneumonia and/or stable sepsis. Secondarily, we identified 30-day readmission rates for aspiration pneumonia from a SNF. The Aspiration Pneumonia Clinical Care Pathway starts in the emergency department (ED) with the initiation of antimicrobials within 4 hours of admission and early recognition of aspiration. Once this is identified, a swallow test is initiated by the bedside nurse, and if the patient demonstrates dysphagia, they are maintained on strict nothing by mouth (NPO) followed by a speech and language pathologist (SLP) referral for an appropriate modified diet recommendation. Aspiration prevention techniques included the avoidance of straws, 45-degree positioning, no talking during meals, taking small bites, placement of the aspiration wrist band, and consuming meals out of the bed in a chair. Nursing education was conducted with a newly created online learning module about aspiration pneumonia. The authors identified 979 patients, with an average age of 73.5 years old, who were diagnosed with aspiration pneumonia on the index hospitalization. These patients were reviewed for a 30-day readmission for aspiration pneumonia or stable sepsis, and mortality rates from January 2021 to December 2022 at Overlook Medical Center (OMC). The 30-day readmission rates were significantly lower in the cohort that received the clinical care pathway (35.0% vs. 27.5%, p = 0.011). When evaluating the mortality rates in the pre and post intervention cohort the authors discovered the mortality rates were lower in the post intervention cohort (23.7% vs 22.4%, p = 0.61) Mortality among non-white (self-reported as non-white) patients were lower in the post intervention cohort (34.4% vs. 21.0% , p = 0.05). Patients who reported as a current smoker/vaper in the pre and post cohorts had increased mortality rates (5.9% vs 22%). There was a decrease in mortality for the male population but an increase in mortality for women in the pre and post cohorts (19% vs. 25%). The authors attributed this increase in mortality in the post intervention cohort to more active smokers, more former smokers, and more being admitted from a SNF. This research identified that implementation of an Aspiration Pneumonia Clinical Care Pathway showed a statistically significant decrease in readmission rates and mortality rates in non-whites. The 30-day readmission rates were lower in the cohort that received the clinical care pathway (35.0% vs. 27.5%, p = 0.011).

Keywords: aspiration pneumonia, mortality, quality improvement, 30-day pneumonia readmissions

Procedia PDF Downloads 22
2013 Ionic Liquid Effects on Metal Ion-Based Extractions of Olefin/Paraffin Hydrocarbon

Authors: Ellen M. Lukasik

Abstract:

In coordination and support of the Center for Innovative and Strategic Transformation of Alkane Resources (CISTAR) Research Experience for Teachers (RET) at the University of Texas at Austin and under the guidance and direction of Professor Joan Brennecke, this study examined the addition of silver in an ionic liquid used to separate cyclohexane from cyclohexene. We recreated the liquid-liquid separation experimental results from the literature on cyclohexene, cyclohexane, and [allylmim][Tf2N] to verify our method, then evaluated the separation performance of silver - ionic liquid (IL) mixtures by various characterization techniques. To introduce the concepts of this research in high school education, a lesson plan was developed to instruct students on the principles of liquid-liquid separation.

Keywords: ionic liquids, liquid-liquid separation, hydrocarbon, research experience for teachers

Procedia PDF Downloads 68
2012 Numerical Simulation and Analysis on Liquid Nitrogen Spray Heat Exchanger

Authors: Wenjing Ding, Weiwei Shan, Zijuan, Wang, Chao He

Abstract:

Liquid spray heat exchanger is the critical equipment of temperature regulating system by gaseous nitrogen which realizes the environment temperature in the range of -180 ℃~+180 ℃. Liquid nitrogen is atomized into smaller liquid drops through liquid nitrogen sprayer and then contacts with gaseous nitrogen to be cooled. By adjusting the pressure of liquid nitrogen and gaseous nitrogen, the flowrate of liquid nitrogen is changed to realize the required outlet temperature of heat exchanger. The temperature accuracy of shrouds is ±1 ℃. Liquid nitrogen spray heat exchanger is simulated by CATIA, and the numerical simulation is performed by FLUENT. The comparison between the tests and numerical simulation is conducted. Moreover, the results help to improve the design of liquid nitrogen spray heat exchanger.

Keywords: liquid nitrogen spray, temperature regulating system, heat exchanger, numerical simulation

Procedia PDF Downloads 284
2011 Force Feedback Enabled Syringe for Aspiration and Biopsy

Authors: Pelin Su Firat, Sohyung Cho

Abstract:

Biopsy or aspiration procedures are known to be complicated as they involve the penetration of a needle through human tissues, including vital organs. This research presents the design of a force sensor-guided device to be used with syringes and needles for aspiration and biopsy. The development of the device was aimed to help accomplish accurate needle placement and increase the performance of the surgeon in navigating the tool and tracking the target. Specifically, a prototype for a force-sensor embedded syringe has been created using 3D (3-Dimensional) modeling and printing techniques in which two different force sensors were used to provide significant force feedback to users during the operations when needles pernitrate different tissues. From the extensive tests using synthetic tissues, it is shown that the proposed syringe design has accomplished the desired accuracy, efficiency, repeatability, and effectiveness. Further development is desirable through usability tests.

Keywords: biopsy, syringe, force sensors, haptic feedback

Procedia PDF Downloads 11
2010 Deep Learning-Based Liver 3D Slicer for Image-Guided Therapy: Segmentation and Needle Aspiration

Authors: Ahmedou Moulaye Idriss, Tfeil Yahya, Tamas Ungi, Gabor Fichtinger

Abstract:

Image-guided therapy (IGT) plays a crucial role in minimally invasive procedures for liver interventions. Accurate segmentation of the liver and precise needle placement is essential for successful interventions such as needle aspiration. In this study, we propose a deep learning-based liver 3D slicer designed to enhance segmentation accuracy and facilitate needle aspiration procedures. The developed 3D slicer leverages state-of-the-art convolutional neural networks (CNNs) for automatic liver segmentation in medical images. The CNN model is trained on a diverse dataset of liver images obtained from various imaging modalities, including computed tomography (CT) and magnetic resonance imaging (MRI). The trained model demonstrates robust performance in accurately delineating liver boundaries, even in cases with anatomical variations and pathological conditions. Furthermore, the 3D slicer integrates advanced image registration techniques to ensure accurate alignment of preoperative images with real-time interventional imaging. This alignment enhances the precision of needle placement during aspiration procedures, minimizing the risk of complications and improving overall intervention outcomes. To validate the efficacy of the proposed deep learning-based 3D slicer, a comprehensive evaluation is conducted using a dataset of clinical cases. Quantitative metrics, including the Dice similarity coefficient and Hausdorff distance, are employed to assess the accuracy of liver segmentation. Additionally, the performance of the 3D slicer in guiding needle aspiration procedures is evaluated through simulated and clinical interventions. Preliminary results demonstrate the effectiveness of the developed 3D slicer in achieving accurate liver segmentation and guiding needle aspiration procedures with high precision. The integration of deep learning techniques into the IGT workflow shows great promise for enhancing the efficiency and safety of liver interventions, ultimately contributing to improved patient outcomes.

Keywords: deep learning, liver segmentation, 3D slicer, image guided therapy, needle aspiration

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2009 Measurement of Liquid Film Thickness in a Vertical Annular Two Phase Flow Changing the Gas-Liquid Density Ratio

Authors: Shoji Mori, Kunito Okuyama

Abstract:

Annular two phase flow is encountered in many industrial equipments, including flow near nuclear fuel rods in boiling water reactor (BWR). Especially, disturbance waves play important roles in the pressure drop, the generation of entrainments, and the dryout of the liquid film. Therefore, it is important to clarify the behavior of disturbance waves and base film. However, most of the previous studies have been performed under atmospheric pressure conditions that provides the properties of liquid and gas which are significantly different from those of a BWR. Therefore, the effect of properties in gas and liquid on liquid film characteristics should be clarified. In this paper we focus on the effect of gas-liquid density ratio on liquid film thickness characteristics. The experiments have been conducted at four density ratio conditions (ρL/ρG =763, 451, 231, and 31). As a result, it is found that and interfacial shear stress collapse not only tF ave but also tF max and tF min successfully under the same liquid mass flow rate conditions irrespective of ρL/ρG, and moreover a non-dimensional parameter tends to collapse tF max,tF ave,and tF min in the wide range of experimental conditions (ρL/ρG:31~763,We:10~1800,ReL:500 ~ 2200).

Keywords: two phase flow, liquid film, annular flow, disturbance wave

Procedia PDF Downloads 361
2008 Removal Cobalt (II) and Copper (II) by Solvent Extraction from Sulfate Solutions by Capric Acid in Chloroform

Authors: A. Bara, D. Barkat

Abstract:

Liquid-liquid extraction is one of the most useful techniques for selective removal and recovery of metal ions from aqueous solutions, applied in purification processes in numerous chemical and metallurgical industries. In this work, The liquid-liquid extraction of cobalt (II) and copper (II) from aqueous solution by capric acid (HL) in chloroform at 25°C has been studied. Our interest in this paper is to study the effect of concentration of capric acid on the extraction of Co(II) and Cu(II) to see the complexes could be formed in the organic phase using various concentration of capric acid. The extraction of cobalt (II) and copper (II) is extracted as the complex CoL2 (HL )2, CuL2 (HL)2.

Keywords: capric acid, Cobalt(II), copper(II), liquid-liquid extraction

Procedia PDF Downloads 407
2007 Biocompatible Ionic Liquids in Liquid-Liquid Extraction of Lactic Acid: A Comparative Study

Authors: Konstantza Tonova, Ivan Svinyarov, Milen G. Bogdanov

Abstract:

Ionic liquids consisting of pairs of imidazolium or phosphonium cation and chloride or saccharinate anion were synthesized and compared with respect to their extraction efficiency towards the fermentative L-lactic acid. The acid partitioning in the equilibrated biphasic systems of ionic liquid and water was quantified through the extraction degree and the partition coefficient. The water transfer from the aqueous into the ionic liquid-rich phase was also always followed. The effect of pH, which determines the state of lactic acid in the aqueous source was studied. The effect of other salting-out substances that modify the ionic liquid/water equilibrium was also investigated in view to reveal the best liquid-liquid system with respect to low toxicity, high extraction and back extraction efficiencies and performance simplicity.

Keywords: ionic liquids, biphasic system, extraction, lactic acid

Procedia PDF Downloads 436
2006 Development of a Smart Liquid Level Controller

Authors: Adamu Mudi, Ibrahim Wahab Fawole, Abubakar Abba Kolo

Abstract:

In this research paper, we present a microcontroller-based liquid level controller that identifies the various levels of a liquid, carries out certain actions, and is capable of communicating with the human being and other devices through the GSM network. This project is useful in ensuring that a liquid is not wasted. It also contributes to the internet of things paradigm, which is the future of the internet. The method used in this work includes designing the circuit and simulating it. The circuit is then implemented on a solderless breadboard, after which it is implemented on a strip board. A C++ computer program is developed and uploaded into the microcontroller. This program instructs the microcontroller on how to carry out its actions. In other to determine levels of the liquid, an ultrasonic wave is sent to the surface of the liquid similar to radar or the method for detecting the level of sea bed. Message is sent to the phone of the user similar to the way computers send messages to phones of GSM users. It is concluded that the routine of observing the levels of a liquid in a tank, refilling the tank when the liquid level is too low can be entirely handled by a programmable device without wastage of the liquid or bothering a human being with such tasks.

Keywords: Arduino Uno, HC-SR04 ultrasonic sensor, internet of things, IoT, SIM900 GSM module

Procedia PDF Downloads 99
2005 Sustainable Separation of Nicotine from Its Aqueous Solutions

Authors: Zoran Visak, Joana Lopes, Vesna Najdanovic-Visak

Abstract:

Within this study, the separation of nicotine from its aqueous solutions, using inorganic salt sodium chloride or ionic liquid (molten salt) ECOENG212® as salting-out media, was carried out. Thus, liquid-liquid equilibria of the ternary solutions (nicotine+water+NaCl) and (nicotine+water+ECOENG212®) were determined at ambient pressure, 0.1 MPa, at three temperatures. The related phase diagrams were constructed in two manners: by adding the determined cloud-points and by the chemical analysis of phases in equilibrium (tie-line data). The latter were used to calculate two important separation parameters - partition coefficients of nicotine and separation factors. The impacts of the initial compositions of the mother solutions and of temperature on the liquid-liquid phase separation and partition coefficients were analyzed and discussed. The results obtained clearly showed that both investigated salts are good salting-out media for the efficient and sustainable separation of nicotine from its solutions with water. However, when compared, sodium chloride exhibited much better separation performance than the ionic liquid.

Keywords: nicotine, liquid-liquid separation, inorganic salt, ionic liquid

Procedia PDF Downloads 271
2004 Perceptions of Farmers against Liquid Fertilizer Benefits of Beef Cattle Urine

Authors: Sitti Nurani Sirajuddin, Ikrar Moh. Saleh, Kasmiyati Kasim

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The aim of this study was to know the perception of livestock farmers on the use of liquid organic fertilizer from urine of cattle at Sinjai Regency, South Sulawesi Province. The choice of location for a farmer group manufactures and markets liquid organic fertilizer from cattle urine. This research was conducted in May to July 2013.The population were all livestock farmers who use organic liquid fertilizer from cattle urine samples while livestock farmers who are directly involved in the manufacture of liquid organic fertilizer totaled 42 people. Data were collected through observation and interview. Data were analyzed descriptively. The results showed that the perception of livestock farmers of using liquid organic fertilizer from cattle urine provide additional revenue benefits, cost minimization farming, reducing environmental pollution which not contrary to the customs.

Keywords: liquid organic fertilizer, perceptions, farmers, beef cattle

Procedia PDF Downloads 432
2003 Sensitive Detection of Nano-Scale Vibrations by the Metal-Coated Fiber Tip at the Liquid-Air Interface

Authors: A. J. Babajanyan, T. A. Abrahamyan, H. A. Minasyan, K. V. Nerkararyan

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Optical radiation emitted from a metal-coated fiber tip apex at liquid-air interface was measured. The intensity of the output radiation was strongly depending on the relative position of the tip to a liquid-air interface and varied with surface fluctuations. This phenomenon permits in-situ real-time investigation of nano-metric vibrations of the liquid surface and provides a basis for development of various origin ultrasensitive vibration detecting sensors. The described method can be used for detection of week seismic vibrations.

Keywords: fiber-tip, liquid-air interface, nano vibration, opto-mechanical sensor

Procedia PDF Downloads 451
2002 Abdominal Exercises Can Modify Abdominal Function in Postpartum Women: A Randomized Control Trial Comparing Curl-up to Drawing-in Combined With Diaphragmatic Aspiration

Authors: Yollande Sènan Djivoh, Dominique de Jaeger

Abstract:

Background: Abdominal exercises are commonly practised nowadays. Specific techniques of abdominal muscles strengthening like hypopressive exercises have recently emerged and their practice is encouraged against the practice of Curl-up especially in postpartum. The acute and the training effects of these exercises did not allow to advise one exercise to the detriment of another. However, physiotherapists remain reluctant to perform Curl-up with postpartum women because of its potential harmful effect on the pelvic floor. Design: This study was a randomized control trial registered under the number PACTR202110679363984. Objective: to observe the training effect of two experimental protocols (Curl-up versus Drawing-in+Diaphragmatic aspiration) on the abdominal wall (interrecti distance, rectus and transversus abdominis thickness, abdominal strength) in Beninese postpartum women. Pelvic floor function (tone, endurance, urinary incontinence) will be assessed to evaluate potential side effects of exercises on the pelvic floor. Method: Postpartum women diagnosed with diastasis recti were randomly assigned to one of three groups (Curl-up, Drawingin+Diaphragmatic aspiration and control). Abdominal and pelvic floor parameters were assessed before and at the end of the 6-week protocol. The interrecti distance and the abdominal muscles thickness were assessed by ultrasound and abdominal strength by dynamometer. Pelvic floor tone and strength were assessed with Biofeedback and urinary incontinence was quantified by pad test. To compare the results between the three groups and the two measurements, a two-way Anova test with repeated measures was used (p<0.05). When interaction was significant, a posthoc using Student t test, with Bonferroni correction, was used to compare the three groups regarding the difference (end value minus initial value). To complete these results, a paired Student t test was used to compare in each group the initial and end values. Results: Fifty-eight women participated in this study, divided in three groups with similar characteristics regarding their age (29±5 years), parity (2±1 children), BMI (26±4 kg/m2 ), time since the last birth (10±2 weeks), weight of their baby at birth (330±50 grams). Time effect and interaction were significant (p<0.001) for all abdominal parameters. Experimental groups improved more than control group. Curl-up group improved more (p=0.001) than Drawing-in+Diaphragmatic aspiration group regarding the interrecti distance (9.3±4.2 mm versus 6.6±4.6 mm) and abdominal strength (20.4±16.4 Newton versus 11.4±12.8 Newton). Drawingin+Diaphragmatic aspiration group improved (0.8±0.7 mm) more than Curl-up group (0.5±0.7 mm) regarding the transversus abdominis thickness (p=0.001). Only Curl-up group improved (p<0.001) the rectus abdominis thickness (1.5±1.2 mm). For pelvic floor parameters, both experimental groups improved (p=0.01) except for tone which improved (p=0.03) only in Drawing-in+Diaphragmatic aspiration group from 19.9±4.1 cmH2O to 22.2±4.5 cmH2O. Conclusion: Curl-up was more efficient to improve abdominal function than Drawingin+Diaphragmatic aspiration. However, these exercises are complementary. None of them degraded the pelvic floor, but Drawing-in+Diaphragmatic aspiration improved further the pelvic floor function. Clinical implications: Curl-up, Drawing-in and Diaphragmatic aspiration can be used for the management of abdominal function in postpartum women. Exercises must be chosen considering the specific needs of each woman’s abdominal and pelvic floor function.

Keywords: curl-up, drawing-in, diaphragmatic aspiration, hypopressive exercise, postpartum women

Procedia PDF Downloads 51
2001 Ionic Liquid Desiccant for the Dehumidification System

Authors: Chih-Hao Chen, Yu-Heng Fang, Jyi-Ching Perng, Wei-Chih Lee, Yi-Hsiang Chen, Jiun-Jen Chen

Abstract:

Emerging markets are almost in the high temperature and high humidity area. Regardless of industry or domestic fields, the energy consumption of air conditioning systems in buildings is always significant. Moreover, the proportion of latent heat load is high. A liquid desiccant dehumidification system is one kind of energy-saving air conditioning system. However, traditional absorbents such as lithium chloride are hindered in market promotion because they will crystallized and cause metal corrosion. This study used the commercial ionic liquid to build a liquid desiccant dehumidification system with an air volume of 300 CMH. When the absolute humidity of the inlet air was 15g/kg, the absolute humidity of the outlet air was 10g/kg. The operating condition of a hot water temperature is 45 °C, and the cooling water temperature is 15 °C. The test result proves that the ionic liquid desiccant can completely replace the traditional liquid desiccant.

Keywords: ionic liquid desiccant, dehumidification, heat pump, air conditioning systems

Procedia PDF Downloads 121
2000 Liquid-Liquid Equilibrium Study in Solvent Extraction of o-Cresol from Coal Tar

Authors: Dewi Selvia Fardhyanti, Astrilia Damayanti

Abstract:

Coal tar is a liquid by-product of the process of coal gasification and carbonation, also in some industries such as steel, power plant, cement, and others. This liquid oil mixture contains various kinds of useful compounds such as aromatic compounds and phenolic compounds. These compounds are widely used as raw material for insecticides, dyes, medicines, perfumes, coloring matters, and many others. This research investigates thermodynamic modelling of liquid-liquid equilibria (LLE) in solvent extraction of o-Cresol from the coal tar. The equilibria are modeled by ternary components of Wohl, Van Laar, and Three-Suffix Margules models. The values of the parameters involved are obtained by curve-fitting to the experimental data. Based on the comparison between calculated and experimental data, it turns out that among the three models studied, the Three-Suffix Margules seems to be the best to predict the LLE of o-Cresol for those system.

Keywords: coal tar, o-Cresol, Wohl, Van Laar, three-suffix margules

Procedia PDF Downloads 239
1999 Electricity Production from Vermicompost Liquid Using Microbial Fuel Cell

Authors: Pratthana Ammaraphitak, Piyachon Ketsuwan, Rattapoom Prommana

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Electricity production from vermicompost liquid was investigated in microbial fuel cells (MFCs). The aim of this study was to determine the performance of vermicompost liquid as a biocatalyst for electricity production by MFCs. Chemical and physical parameters of vermicompost liquid as total nitrogen, ammonia-nitrogen, nitrate, nitrite, total phosphorus, potassium, organic matter, C:N ratio, pH, and electrical conductivity in MFCs were studied. The performance of MFCs was operated in open circuit mode for 7 days. The maximum open circuit voltage (OCV) was 0.45 V. The maximum power density of 5.29 ± 0.75 W/m² corresponding to a current density of 0.024 2 ± 0.0017 A/m² was achieved by the 1000 Ω on day 2. Vermicompost liquid has efficiency to generate electricity from organic waste.

Keywords: vermicompost liquid, microbial fuel cell, nutrient, electricity production

Procedia PDF Downloads 143
1998 Phase Diagrams and Liquid-Liquid Extraction in Aqueous Biphasic Systems Formed by Polyethylene Glycol and Potassium Sodium Tartrate at 303.15 K

Authors: Amanda Cristina de Oliveira, Elias de Souza Monteiro Filho, Roberta Ceriani

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Liquid-liquid extraction in aqueous two-phase systems (ATPSs) constitutes a powerful tool for purifying bio-materials, such as cells, organelles, proteins, among others. In this work, the extraction of the bovine serum albumin (BSA) has been studied in systems formed by polyethylene glycol (PEG) (1500, 4000, and 6000 g.mol⁻¹) + potassium sodium tartrate + water at 303.15°K. Phase diagrams were obtained by turbidimetry and Merchuk’s method (1998). The experimental tie-lines were described using the Othmer-Tobias and Bancroft correlations. ATPSs were correlated with the nonrandom two-liquid (NRTL) model. The results were considered excellent according to global root-mean-square deviations found which were between 0,72 and 1,13%. The concentrations of the proteins in each phase were determined by spectrophotometry at 280 nm, finding partition efficiencies greater than 71%.

Keywords: aqueous two phases systems, bovine serum albumin , liquid-liquid extraction, polyethylene glycol

Procedia PDF Downloads 110
1997 Thermodynamic Modelling of Liquid-Liquid Equilibria (LLE) in the Separation of p-Cresol from the Coal Tar by Solvent Extraction

Authors: D. S. Fardhyanti, Megawati, W. B. Sediawan

Abstract:

Coal tar is a liquid by-product of the process of coal gasification and carbonation. This liquid oil mixture contains various kinds of useful compounds such as aromatic compounds and phenolic compounds. These compounds are widely used as raw material for insecticides, dyes, medicines, perfumes, coloring matters, and many others. This research investigates thermodynamic modelling of liquid-liquid equilibria (LLE) in the separation of phenol from the coal tar by solvent extraction. The equilibria are modeled by ternary components of Wohl, Van Laar, and Three-Suffix Margules models. The values of the parameters involved are obtained by curve-fitting to the experimental data. Based on the comparison between calculated and experimental data, it turns out that among the three models studied, the Three-Suffix Margules seems to be the best to predict the LLE of p-Cresol mixtures for those system.

Keywords: coal tar, phenol, Wohl, Van Laar, Three-Suffix Margules

Procedia PDF Downloads 223
1996 Waste Management in a Hot Laboratory of Japan Atomic Energy Agency – 2: Condensation and Solidification Experiments on Liquid Waste

Authors: Sou Watanabe, Hiromichi Ogi, Atsuhiro Shibata, Kazunori Nomura

Abstract:

As a part of STRAD project conducted by JAEA, condensation of radioactive liquid waste containing various chemical compounds using reverse osmosis (RO) membrane filter was examined for efficient and safety treatment of the liquid wastes accumulated inside hot laboratories. NH4+ ion in the feed solution was successfully concentrated, and NH4+ ion involved in the effluents became lower than target value; 100 ppm. Solidification of simulated aqueous and organic liquid wastes was also tested. Those liquids were successfully solidified by adding cement or coagulants. Nevertheless, optimization in materials for confinement of chemicals is required for long time storage of the final solidified wastes.

Keywords: condensation, radioactive liquid waste, solidification, STRAD project

Procedia PDF Downloads 111
1995 Research Developments in Vibration Control of Structure Using Tuned Liquid Column Dampers: A State-of-the-Art Review

Authors: Jay Gohel, Anant Parghi

Abstract:

A tuned liquid column damper (TLCD) is a modified passive system of tuned mass damper, where a liquid is used in place of mass in the structure. A TLCD consists of U-shaped tube with an orifice that produces damping against the liquid motion in the tube. This paper provides a state-of-the-art review on the vibration control of wind and earthquake excited structures using liquid dampers. Further, the paper will also discuss the theoretical background of TCLD, history of liquid dampers and existing literature on experimental, numerical, and analytical study. The review will also include different configuration of TLCD viz single TLCD, multi tuned liquid column damper (MTLCD), TLCD-Interior (TLCDI), tuned liquid column ball damper (TLCBD), tuned liquid column ball gas damper (TLCBGD), and pendulum liquid column damper (PLCD). The dynamic characteristics of the different configurate TLCD system and their effectiveness in reducing the vibration of structure will be discussed. The effectiveness of semi-active TLCD will be also discussed with reference to experimental and analytical results. In addition, the review will also provide the numerous examples of implemented TLCD to control the vibration in real structures. Based on the comprehensive review of literature, some important conclusions will be made and the need for future research will be identified for vibration control of structures using TLCD.

Keywords: earthquake, wind, tuned liquid column damper, passive response control, structures

Procedia PDF Downloads 172
1994 Temperature Effect on Sound Propagation in an Elastic Pipe with Viscoelastic Liquid

Authors: S. Levitsky, R. Bergman

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Fluid rheology may have essential impact on sound propagation in a liquid-filled pipe, especially, in a low frequency range. Rheological parameters of liquid are temperature-sensitive, which ultimately results in a temperature dependence of the wave speed and attenuation in the waveguide. The study is devoted to modeling of this effect at sound propagation in an elastic pipe with polymeric liquid, described by generalized Maxwell model with non-zero high-frequency viscosity. It is assumed that relaxation spectrum is distributed according to the Spriggs law; temperature impact on the liquid rheology is described on the basis of the temperature-superposition principle and activation theory. The dispersion equation for the waveguide, considered as a thin-walled tube with polymeric solution, is obtained within a quasi-one-dimensional formulation. Results of the study illustrate the influence of temperature on sound propagation in the system.

Keywords: elastic tube, sound propagation, temperature effect, viscoelastic liquid

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1993 Analysis of Evaporation of Liquid Ammonia in a Vertical Cylindrical Storage Tank

Authors: S. Chikh, S. Boulifa

Abstract:

The present study addresses the problem of ammonia evaporation during filling of a vertical cylindrical tank and the influence of various external factors on the stability of storage by determining the conditions for minimum evaporation. Numerical simulation is carried out by solving the governing equations namely, continuity, momentum, energy, and diffusion of species. The effect of temperature of surrounding air, the filling speed of the reservoir and the temperature of the filling liquid ammonia on the evaporation rate is investigated. Results show that the temperature of the filling liquid has little effect on the liquid ammonia for a short period, which, in fact, is function of the filling speed. The evaporation rate along the free surface of the liquid is non-uniform. The inlet temperature affects the vapor ammonia temperature because of pressure increase. The temperature of the surrounding air affects the temperature of the vapor phase rather than the liquid phase. The maximum of evaporation is reached at the final step of filling. In order to minimize loss of ammonia vapors automatically causing losses in quantity of the liquid stored, it is suggested to ensure the proper insulation for the walls and roof of the reservoir and to increase the filling speed.

Keywords: evaporation, liquid ammonia, storage tank, numerical simulation

Procedia PDF Downloads 248
1992 Study the Sloshing Phenomenon in the Tank Filled Partially with Liquid Using Computational Fluid Dynamics (CFD) Simulation

Authors: Amit Kumar, Jaikumar V, Pradeep AG, Shivakumar Bhavi

Abstract:

Reducing sloshing is one of the major challenges in industries where transporting of liquid involved. The present study investigates the sloshing effect for different liquid levels 25%, 50%, and 75% of the tank capacity. CFD simulation for three different liquid levels has been carried out using a time-based multiphase Volume of fluid (VOF) scheme. Baffles were introduced to examine the sloshing effect inside the tank. Results were compared against the baseline case to assess the effectiveness of baffles. Maximum liquid height over the period of the simulation was considered as the parameter for measuring the sloshing effect inside the tank. It was found that the addition of baffles reduced the sloshing effect inside the tank as compared to the baseline model.

Keywords: sloshing, CFD, VOF, baffles

Procedia PDF Downloads 211
1991 The Experimental Investigation of Temperature Influence on the Oscillations of Particles on Liquid Surfaces

Authors: Sathish K. Gurupatham, Farhad Sayedzada, Naji Dauk, Valmiki Sooklal, Laura Ruhala

Abstract:

It was shown recently that small particles and powders spontaneously disperse on liquid surfaces when they come into contact with the interface for the first time. This happens due to the combined effect of the capillary force, buoyant weight of the particle and the viscous drag that the particle experiences in the liquid. The particle undergoes oscillations normal to the interface before it comes to rest on the interface. These oscillations, in turn, induce a flow on the interface which disperses the particles radially outward. This phenomenon has a significant role in the pollination of sea plants such as Ruppia in which the formation of ‘pollen rafts’ is the first step. This paper investigates, experimentally, the influence of the temperature of the liquid on which this dispersion occurs. It was observed that the frequency of oscillations of the particles decreased with the increase in the temperature of the liquid. It is because the magnitude of capillary force also decreased when the temperature of the liquid increased.

Keywords: particle dispersion, capillary force, viscous drag, oscillations

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1990 Phase Segregating and Complex Forming Pb Based (=X-Pb) Liquid Alloys

Authors: Indra Bahadur Bhandari, Narayan Panthi, Ishwar Koirala, Devendra Adhikari

Abstract:

We have used a theoretical model based on the assumption of compound formation in binary alloys to study the thermodynamic, microscopic, and surface properties of Bi-Pb and In-Pb liquid alloys. A review of the phase diagrams for these alloys shows that one of the stable complexes for Bi-Pb liquid alloy is BiPb3; also, that InPb is a stable phase in liquid In-Pb alloys. Using the same interaction parameters that are fitted for the free energy of mixing, we have been able to compute the bulk and thermodynamic properties of the alloys. From our observations, we are able to show that the Bi-Pb liquid alloy exhibits compound formation over the whole concentration range and the In-Pb alloys undergo phase separation. With regards to surface properties, Pb segregates more to the surface in In-Pb alloys than in Bi-Pb alloys. The viscosity isotherms have a positive deviation from ideality for both Bi-Pb and In-Pb alloys.

Keywords: asymmetry, Bi-Pb, deviation, In-Pb, interaction parameters

Procedia PDF Downloads 125
1989 Experimental Investigations on the Mechanism of Stratified Liquid Mixing in a Cylinder

Authors: Chai Mingming, Li Lei, Lu Xiaoxia

Abstract:

In this paper, the mechanism of stratified liquids’ mixing in a cylinder is investigated. It is focused on the effects of Rayleigh-Taylor Instability (RTI) and rotation of the cylinder on liquid interface mixing. For miscible liquids, Planar Laser Induced Fluorescence (PLIF) technique is applied to record the concentration field for one liquid. Intensity of Segregation (IOS) is used to describe the mixing status. For immiscible liquids, High Speed Camera is adopted to record the development of the interface. The experiment of RTI indicates that it plays a great role in the mixing process, and meanwhile the large-scale mixing is triggered, and subsequently the span of the stripes decreases, showing that the mesoscale mixing is coming into being. The rotation experiments show that the spin-down process has a great role in liquid mixing, during which the upper liquid falls down rapidly along the wall and crashes into the lower liquid. During this process, a lot of interface instabilities are excited. Liquids mix rapidly in the spin-down process. It can be concluded that no matter what ways have been adopted to speed up liquid mixing, the fundamental reason is the interface instabilities which increase the area of the interface between liquids and increase the relative velocity of the two liquids.

Keywords: interface instability, liquid mixing, Rayleigh-Taylor Instability, spin-down process, spin-up process

Procedia PDF Downloads 265
1988 Management of Dysphagia after Supra Glottic Laryngectomy

Authors: Premalatha B. S., Shenoy A. M.

Abstract:

Background: Rehabilitation of swallowing is as vital as speech in surgically treated head and neck cancer patients to maintain nutritional support, enhance wound healing and improve quality of life. Aspiration following supraglottic laryngectomy is very common, and rehabilitation of the same is crucial which requires involvement of speech therapist in close contact with head and neck surgeon. Objectives: To examine the functions of swallowing outcomes after intensive therapy in supraglottic laryngectomy. Materials: Thirty-nine supra glottic laryngectomees were participated in the study. Of them, 36 subjects were males and 3 were females, in the age range of 32-68 years. Eighteen subjects had undergone standard supra glottis laryngectomy (Group1) for supraglottic lesions where as 21 of them for extended supraglottic laryngectomy (Group 2) for base tongue and lateral pharyngeal wall lesion. Prior to surgery visit by speech pathologist was mandatory to assess the sutability for surgery and rehabilitation. Dysphagia rehabilitation started after decannulation of tracheostoma by focusing on orientation about anatomy, physiological variation before and after surgery, which was tailor made for each individual based on their type and extent of surgery. Supraglottic diet - Soft solid with supraglottic swallow method was advocated to prevent aspiration. The success of intervention was documented as number of sessions taken to swallow different food consistency and also percentage of subjects who achieved satisfactory swallow in terms of number of weeks in both the groups. Results: Statistical data was computed in two ways in both the groups 1) to calculate percentage (%) of subjects who swallowed satisfactorily in the time frame of less than 3 weeks to more than 6 weeks, 2) number of sessions taken to swallow without aspiration as far as food consistency was concerned. The study indicated that in group 1 subjects of standard supraglottic laryngectomy, 61% (n=11) of them were successfully rehabilitated but their swallowing normalcy was delayed by an average 29th post operative day (3-6 weeks). Thirty three percentages (33%) (n=6) of the subjects could swallow satisfactorily without aspiration even before 3 weeks and only 5 % (n=1) of the needed more than 6 weeks to achieve normal swallowing ability. Group 2 subjects of extended SGL only 47 %( n=10) of them could achieved satisfactory swallow by 3-6 weeks and 24% (n=5) of them of them achieved normal swallowing ability before 3 weeks. Around 4% (n=1) needed more than 6 weeks and as high as 24 % (n=5) of them continued to be supplemented with naso gastric feeding even after 8-10 months post operative as they exhibited severe aspiration. As far as type of food consistencies were concerned group 1 subject could able to swallow all types without aspiration much earlier than group 2 subjects. Group 1 needed only 8 swallowing therapy sessions for thickened soft solid and 15 sessions for liquids whereas group 2 required 14 sessions for soft solid and 17 sessions for liquids to achieve swallowing normalcy without aspiration. Conclusion: The study highlights the importance of dysphagia intervention in supraglottic laryngectomees by speech pathologist.

Keywords: dysphagia management, supraglotic diet, supraglottic laryngectomy, supraglottic swallow

Procedia PDF Downloads 204