Port Valve Research Articles

A novel analytical pyrolysis device applicable for measurements of less volatile pyrolyzates

A novel analytical pyrolysis device suitable for the measurements of the less volatile pyrolyzates was developed. This device is comprised of a pyrolysis unit based on the vertical microfurnace pyrolyzer and a movable pyrolysis tube made of stainless steel. The upper side of the pyrolysis tube is first set at the heated center of the pyrolysis unit. A polymer sample in a sample cup is introduced into the heated center and pyrolyzed under the flow of nitrogen carrier gas. The pyrolyzates are then transferred to the bottom side of the pyrolysis tube which is cooled down by air blow and the less volatile pyrolyzates are condensed. After that the pyrolysis tube is moved down out of the pyrolysis unit and blocked from the hot zone by moving the three port valve. Finally the trapped pyrolyzates are flushed by an appropriate solvent into a collection vial. The recovered pyrolyzates in the solution can be then subjected to the measurements suitable for less volatile products such as matrix-assisted laser desorption/ionization mass spectrometry. Moreover, this device is also on-line connected to the injection port of a high performance liquid chromatographic system, which is also appropriate for the measurements of oligomeric products. The basic performance of the developed device was tested by using some polymer samples forming less volatile pyrolyzates such as poly(butylene terephthalate) and poly(2,6-dimethyl-1,4-phenylene ether). In addition, the usefulness of this method was demonstrated through the characterization of the crosslinking sequences in a photocured resin combined with the thermally-assisted hydrolysis and methylation reaction.

Gas leak due to faulty actuating spindles in a Tec 7 vaporizer

To the Editor: We recently experienced an unexpected gas leak from a vaporizer unit. No significant gas leak from any part of the breathing circuit was detected by the anesthesiologist during his routine pre-use check. However, following induction of anesthesia with propofol and sevoflurane, he noticed that the reservoir bag was gradually deflating, resulting in insufficient ventilation via a face mask despite full closure of the adjustable pressure limiting valve. Initially assuming that the cause of the deflated bag was an inadequate fit of the face mask, the anesthesiologist immediately performed tracheal intubation in the patient and started mechanical ventilation. A few minutes later he noticed that the bellows inside the ventilator was gradually shrinking while the ventilator was operating, implying a significant leak from the gas supply line. The anesthesia machine was replaced as soon as possible. GE Healthcare Japan, the importer of this anesthesia machine, reported that the major cause of the gas leak was a malfunction of the port valve actuating spindles in a Tec 7 vaporizer. When the vaporizer functions normally, these spindles descend synchronously and equidistantly and open the manifold port valves of the anesthesia machine, thereby enabling fresh gas to flow into the vaporizer once the the vaporizer control dial has been turned on. For some reason that remains unknown, in the present case two spindles, which had been adjusted 9 years previously, descended asynchronously and to different lengths (Electronic Supplementary Material Figs. 1, 2), leading to incomplete sealing around the holes by the flanges of the spindles and, consequently, the escape of gas from the vaporizer. We should be aware that the port valve actuating spindle is an important but potentially hazardous component of a Tec 7 vaporizer.

Autonomous, waste-free eluent generation and suppression in a single device: Electrodialytic eluent reflux for ion chromatography

Eluent reflux provides a new approach to suppress and reflux (recover) eluent without the continuous generation of chromatographic waste. The current work utilized a device containing ion exchange membranes at the electrodes, in order to prohibit electrolysis gases from entering the eluent stream. Two resin beds (separated by a membrane stack) were responsible for suppressing incoming eluent and regenerating the suppressed eluent to nearly its original concentration after detection. A greater than expected dilution in the eluent concentration was observed as a result of the minor leakage of potassium ions through the anion membrane stack into the electrode chamber. The incomplete recovery of the eluent was offset by the addition of a three port valve (DRV) to regulate eluent concentration. Over 48 h of continuous operation (192 injections), the device's performance was stable (RSD of 0.21% with the three port valve, compared to RSD 3.73% without). The device was able to operate for up to four weeks using 1L of eluent. Chromatograms showing the reproducibility of the device are presented for anions.

A Novel Procedure for Introducing a Large Gauze into the Corporeal Cavity by Using a Slim Trocar (the Tornado Gauze Procedure)

When a large gauze is needed during a single-incision surgery or reduced port surgery using slim (5-mm) trocars, the operation needs to be interrupted to introduce the gauze via an incision or to change to a large trocar. We describe here a novel procedure for introducing a large gauze into the corporeal cavity by using a slim trocar, called the "Tornado gauze procedure" (TGP). Commercially packed Trox(®) (Osaki Medical, Nagoya, Japan) gauze (30×150 mm, 4-ply) and a specially ordered precision stainless steel tube (Smart introducer; Kinugawa Factory, Kyoto, Japan) are used for the TGP. The gauze is screwed into the Smart introducer. When the surgeon needs a gauze, a Smart introducer with a gauze is set into the 5-mm trocar; then, the 5-mm grasper is used to push the gauze into the corporeal cavity with small screwing-in movements. The gauze is also gently removed from the corporeal cavity through a 5-mm trocar. This procedure efficiently and safely introduced the gauze for hemostasis, blunt dissection, suction filtering, and organ retraction without interrupting the pneumoperitoneum to introduce the gauze in single-incision laparoscopic cholecystectomy, transabdominal preperitoneal hernia repairs, and appendectomy, with good visualization and adequate working space. The rhythm of surgery remains undisturbed with the use of the TGP, even in a high-risk and high-stress situation. The port's valves were not disabled during surgery, and no procedure-related complications were reported. TGP is expected to be helpful to surgeons and enhance the safety of laparoscopic surgeries involving the use of slim trocars.

608 ガソリンポートインジェクタによる壁面衝突噴霧の液膜厚さ計測(OS8-2 内燃機関の燃焼改善II,OS8 内燃機関の燃焼改善)

In gasoline engines, port injected fuel impinges .on the wall of intake port and intake valves. Adhered fuel affects exhaust emissions. It is important to understand the liquid fuel thickness and its area formed by impinging on a wall for the decision of injector position and characteristics. In this paper, the liquid fuel thickness formed by impinging on a flat wall was measured using laser induced fluorescence method. The effect of properties of spray and the distance between the injector and the flat wall on the liquid fuel thickness and its area was investigated. The result shows that the liquid fuel is distributed in a ring shape at any distance and with any injector type. The less the hole of nozzle is, the less the fuel attachment takes.

Simulation of Fluid Flow, Combustion and Heat Transfer Processes in Internal Combustion Engines

The better understanding and optimization of fluid flow, injection, mixing and combustion processes in internal combustion engines are of critical importance in regard to compliance of the emission standards. Presented here is a complex simulation method, which provides transient fluid flow results in a cylinder of a gasoline engine. The model includes moving boundaries. Through the intake port and open intake valve, air is flown into the combustion chamber. Fuel is injected. In the compression stroke, after closing the intake valve, the mixing process is shown. At the top dead center (TDC) ignition is set, which results in combustion of the fuel-air mixture in the power stroke. In the exhaust stroke the burnt gases leave the combustion chamber through the open exhaust valve and the exhaust port. With the results of this simulation, it is possible to determine the temperature and heat transfer coefficients on the walls of the combustion chamber, and to define the thermal load. This load can later be used in a structural analysis of the parts of the combustion chamber, where heat transfer and expansion is calculated.

Evaluation of ThoraQuik: a new device for the treatment of pneumothorax and pleural effusion

BackgroundThoraQuik is a device with a unique design incorporating an aspiration port and one-way valve controlled by a three-way tap, fit for purpose for the treatment of pneumothorax and pleural...

SMC product development brings energy-saving two port valve rewards

SMC product development brings energy-saving two port valve rewards

Research on the port valve of a water hydraulic axial pump

Water hydraulics using water as the working media is paid more attention because of its many advantages compared with oil ones. Water hydraulic pump is the key component in the applications of water hydraulics. Compared with the water hydraulic pump with port plate, the one with port valve has stronger anti-pollution ability and is more suitable for the open system where the working media cannot be filtered finely. For this kind of pump, the characteristics of port valve have direct and significant influences on the flow and pressure characteristics of the pump. In this article, the flow and pressure characteristics of different valves were compared experimentally and a disc valve was selected as the port valve. Then the mathematical model of a single-piston pump with port valve was built and the influences of different factors including spring rigidity, working pressure, etc. on the port valve were analysed. At last, a single-piston pump was developed to test the characteristics of the port valve. Based on these researches, some principles that should be abided in the design of the port valve were suggested.

Spatial flow velocity distribution around an inlet port/valve annulus

An experimental investigation of the airflow through inlet port of a standard production direct injection diesel engine is presented. The investigation comprises mass flow rate and pressure drop measurements at fixed valve lifts, and spatial distributions of mean and r.m.s. velocity components around the port/valve annulus measured under steady flow conditions by special designed miniature hot-wire anemometer X probe. The results show that the velocity field is distributed non-uniformly across the valve gap and around valve periphery. Nonuniformity is more expressed at higher valve lifts. Flow instability in a jet leaving the port (jet flapping) is also evident since the skewness and kurtosis of the velocity probability distribution function depart from the Gaussian form. The presented experimental method, based on the application of miniature multiple hot-wire probes, makes possible investigation of flow performances of an inlet port and poppet valve assembly of a production engine head without any modification for ensuring an optical access within the port/cylinder.

Long-term operation of a small biogas/diesel dual-fuel engine for on-farm electricity generation

Biogas from anaerobic digestion of animal manure waste can be used as a renewable energy source for on-farm power generation. In this study, biogas was used in a single-cylinder, direct-injection, compression ignition engine, which has been modified to operate under dual-fuel condition to generate electricity. The primary fuel is biogas, which is ignited by a pilot diesel liquid injection. Long-term engine operation up to 2000 h was carried out. Performance in terms of output power, specific fuel consumption and thermal efficiency was evaluated over a fixed load and a range of engine speeds, and compared against a conventional diesel engine for the first 50 h of operation. Engine components were weighed, inspected visually and given rating for wear, at the start and after 2000 h of operation. Results indicated that short-term performance between conventional diesel and dual-fuel operations was comparable. Biogas/diesel dual-fuel engine was observed to operate successfully with biogas substitution rate at above 90% by mass. Long-term fuel economy was not found to be adversely affected by running time, and the engine was able to maintain 1.45 kW output of electricity throughout the period. Thin layers of carbon deposits were found to build up on the piston, combustion chamber wall, the intake port and exhaust valve stems. Minor surface wear was evident but not significant enough to cause deterioration in engine performance. Overall, the dual-fuel engine appeared to perform well and have great potential for useful on-farm energy utilisation.

2303 マイクロリアクタ用三方弁の開発とスラグ流の実施(OS8-1 アクチュエータシステム(1))

2303 マイクロリアクタ用三方弁の開発とスラグ流の実施(OS8-1 アクチュエータシステム(1))

Determination of aromatic hydrocarbons in gasolines by flow modulated comprehensive two-dimensional gas chromatography

Valve based/flow modulated comprehensive two-dimensional gas chromatography–flame ionization detection (GC × GC–FID) was used for quantification of C 6 through C 12 aromatic hydrocarbons by carbon number in gasolines. A 0.53 mm i.d. non-polar first dimension column was coupled to a 0.53 mm i.d. polar second dimension column through a double loop eight port valve modulator. Depending on the sample type, normalized percent and internal standard (I.S.) quantification was performed. For normalized percent quantification, a one-point calibration performed with one aromatic compound per carbon number/class provided an average % accuracy of 2.1% and a short-term n − 1 relative standard deviation of 1.0%. For total aromatic compounds good agreement with the more complex conventional multidimensional GC technique was obtained. However, GC × GC has certain advantages over most other methods, mainly increased selectivity for total and carbon number aromatic content. The identification of the aromatic hydrocarbons was confirmed by GC × GC–MS.

A stone extraction facilitation device to achieve an improved technique for performing LCBDE

Laparoscopic common bile duct exploration (LCBDE) has proved to be a safe, cost-effective way to treat common bile duct (CBD) stones. Despite this, LCBDE has not gained widespread adoption by surgeons. The technique has proved difficult to master, and damage to the fragile choledochoscope by grasping forceps and passage through the port valves has been problematic. Cases involving large, impacted, or multiple stones have required conversion to open exploration of CBD. The Multichannel Instrument Guide (MIG) is introduced as a solution for these problems. The MIG is a J-shaped plastic extrusion with three lumens. It is flexible and can be straightened for insertion through a 10-mm port. The MIG facilitates insertion of a flexible 2.8- to 3.2-mm choledochoscope into the CBD. At the same time, additional tools such as balloon or irrigation catheters and lithotripters can be introduced into the CBD. These can be manipulated under video guidance via the choledochoscope. This procedural multitasking allows for a more efficient LCBDE. The authors describe their initial experience using the MIG for 23 patients. Of the 23 patients who underwent LCBDE procedures, 20 had stones in the CBD. Multiple stones were present in 48% of the patients; impacted stones were present in 26% of the patients; and stones larger than 1 cm were present in 26% of the patients. A 95% stone clearance rate was achieved. Difficult cases with large, impacted or multiple stones were resolved using the MIG. Two choledochoscopes were damaged; one during surgery and one during cleaning and storage. The MIG has demonstrated significant advantages over previously described techniques. The device secures biliary tract access and allows procedural multitasking while protecting the delicate and expensive equipment. Subsequently, a simplified technique algorithm can be followed that may encourage more surgeons to adopt the routine performance of LCBDE.

DETERMINATION OF CIPROFLOXACIN AND ITS METABOLITES IN URINE, USING ON-LINE SPE

An isocratic high-performance liquid chromatographic method with column switching and a direct injection system was developed to determine ciprofloxacin, a kind of quinolone derivative and its four kinds of metabolites in urine. A manually actuated system equipped with six port valves allowed a clean-up step with 0.01 M NaH2PO4 (pH 7.0) and the transfer of the analyte by a backflush mode. Also, the sample pretreatment condition for spiked urine was investigated to determine the optimum SPE condition for all analytes. All analytes showed over 92% recovery, using C18(10 μm, 30−50 μm), XAD-2 and XAD-4 as precolumn.

Sigmoid irrigation tube for the management of chronic evacuation disorders

Background/Purpose: Antegrade colonic irrigation, in which the right colon is accessed via appendicostomy or cecostomy, now is an important adjunct in the management of children with chronic evacuation disorders. However, in most children, the major area of dysfunction is the left rather than the right colon. The authors developed a simple, percutaneous endoscopic, laparoscopically controlled sigmoid irrigation tube placement and evaluated the results in 4 children. Methods: A rigid sigmoidoscope is advanced into the upper sigmoid and the loop brought in contact with the abdominal wall under laparoscopic control. A small skin incision is made and a needle pushed across the abdominal and sigmoid walls into the lumen of the sigmoidoscope. A guide wire is advanced through the needle into the scope and retrieved. After the scope is removed, a PEG-type catheter is attached to the guide wire and pulled back, securing the sigmoid loop to the abdominal wall. The tube is subsequently converted to a skin-level device by simply adding an external port valve. Results: All 4 patients achieved prompt evacuation in the sitting position. Conclusions: Sigmoid tube for antegrade irrigation is an appealing alternative to conventional cecal access. The procedure is simple and may offer physiologic advantages.

DETERMINATION OF CIPROFLOXACIN AND ITS METABOLITES IN URINE, USING ON-LINE SPE

An isocratic high-performance liquid chromatographic method with column switching and a direct injection system was developed to determine ciprofloxacin, a kind of quinolone derivative and its four kinds of metabolites in urine. A manually actuated system equipped with six port valves allowed a clean-up step with 0.01 M NaH2PO4 (pH 7.0) and the transfer of the analyte by a backflush mode. Also, the sample pretreatment condition for spiked urine was investigated to determine the optimum SPE condition for all analytes. All analytes showed over 92% recovery, using C18(10 μm, 30−50 μm), XAD-2 and XAD-4 as precolumn.

A ceramic electrochemical microreactor for the methoxylation of methyl-2-furoate with direct mass spectrometry coupling.

A ceramic electrochemical reactor (CEM) devoted to electrosyntheses was developed. The CEM was constituted by the assembly of five structured ceramic layers. On one layer, platinum interdigitated band electrodes with a submillimetre interelectrode gap were screen-printed. The microreactor chamber was constituted by seven channels and its volume was less than 100 microL. After a sintering step at 850 degree C for 1 h, the CEM appeared as a solid and compact unit. The CEM was directly connected to the six port valve of a mass spectrometer allowing an on-line sampling and analysis of the reaction mixture. The methoxylation of the methyl-2-furoate was carried out and the effect of the residence time in the CEM was investigated thanks to mass spectrometry analyses.

On‐line solvent evaporator for coupled normal phase‐reversed phase high‐performance liquid chromatography systems: Heavy polycyclic aromatic hydrocarbons analysis

AbstractAn on‐line system for coupling a normal phase liquid chromatography (LC) column to a reversed‐phase LC column is described. The interface consists of an on‐line solvent evaporator working on the principles of concurrent eluent evaporation and vapor overflow, and two additional 10 port valves. Optimization of the on‐line procedure as well as recoveries, repeatability and linearity characteristics were tested in a simplified system simulating determination of heavy polycyclic aromatic hydrocarbons in edible oils. An application on a real extra virgin olive oil sample is also reported. © 2001 John Wiley & Sons, Inc. J Micro Sep 13: 13–18, 2001

A simple and reliable method of detecting variant transthyretins by multidimensional liquid chromatography coupled to electrospray ionization mass spectrometry

Transthyretin (TTR) variants cause amyloidosis. A method, originally reported by us, of detecting the variants by high performance liquid chromatography / electrospray ionization mass spectrometry (ESIMS) using materials precipitated with anti-TTR antiserum, has been successfully applied by several institutions. The method is simple and reliable, but some variants may not precipitate with the antiserum or may precipitate in different yields compared to normal TTR. Moreover, unidentified minor peaks were observed, which may have been derived from cross reactive materials. We have now devised a new procedure to overcome these problems. An anion exchange and reversed phase liquid chromatography system and ESI mass spectrometer were connected in a tandem fashion using a 6 port valve and a protein trap cartridge. The profile of ion peaks by the method was the same as that by MS with immunopre-cipitates. The minor peaks were proved not to be derived from cross reactive materials, and the molecular species of these peaks were characterized. This method is faster than immunoprecipitation method and using no antibody is a great benefit. The method can be applied widely to the study various proteins, when antibodies are not available.