Tube Orifice Research Articles

Unexpected difficulty in ventilating the lungs after tracheal intubation -A case report-

We experienced difficulty in ventilating the lungs of a patient after tracheal intubation. After intubation, an insufficient amount of tidal volume (VT) was delivered to the patient and the fiberoptic bronchoscopic examination identified partial abutment of the endotracheal tube (ETT) orifice against the tracheal wall. After various attempts to correctly place the ETT, a double-lumen endotracheal tube was placed to achieve a sufficient VT. It is important to notice that even an appropriately placed ETT may get obstructed due to the left sided bevel at its tip.

Numerical Modeling of Refrigerants Flowing through Short Tube Orifices

A numerical model is developed for predicting the mass flow rates of a refrigerant flowing through short tube orifices under various working conditions. The numerical model is theoretically based and not refrigerant-oriented though the majority of past works are based on semi-empirical correlations. The metastable state flow is considered in the numerical model, and the critical flow condition at the outlet is directly obtained by using the analytical two-phase critical model. The comparison between the predicted mass flow rates and the experiment data obtained from literatures shows that the mean absolute deviations (MADs) for R-410A, R-407C, and R-134a are 6.91%, 5.33%, and 7.09%, respectively. The accuracy of this numerical model provides the basis for a more detailed and theoretical analyses of refrigerant flowing characteristics in short tube orifices, such as the determination of flow regimes and variation of inception of vaporization. Also, the effects of working conditions such as upstream pressure and inlet subcooling degree on the mass flow rates are theoretically studied using the developed numerical modeling technique, which shows exact trends as experiment data.

Controlling the Adsorption Kinetics via Nanostructuring: Pd Nanoparticles on TiO2Nanotubes

Activity and selectivity of supported catalysts critically depend on transport and adsorption properties. Combining self-organized porous oxide films with different metal deposition techniques, we have prepared novel Pd/TiO(2) catalysts with a new level of structural control. It is shown that these systems make it possible to tune adsorption kinetics via their nanostructure. Self-organized TiO(2) nanotubular arrays (TiNTs) prepared by electrochemical methods are used as a support, on which Pd particles are deposited. Whereas physical vapor deposition (PVD) in ultrahigh vacuum (UHV) allows us to selectively grow Pd particles at the tube orifice, Pd/TiNT systems with homogeneously distributed Pd aggregates inside the tubes are available by particle precipitation (PP) from solution. Both methods also provide control over particle size and loading. Using in-situ infrared reflection absorption spectroscopy (IRAS) and molecular beam (MB) methods, we illustrate the relation between the nanostructure of the Pd/TiNT systems and their adsorption kinetics. Control over the metal nanoparticle distribution in the nanotubes leads to drastic differences in adsorption probability and saturation behavior. These differences are rationalized based on differences in surface and gas phase transport resulting from their nanostructure. The results suggest that using carefully designed metal/TiNT systems it may be possible to tailor transport processes in catalytically active materials.

Three-Dimensional Image Analysis of the Temporal Bone in Patients with Unilateral Attic Cholesteatoma

We determined temporal bone anatomy in patients with unilateral attic cholesteatoma. We compared the affected and normal ears of ten patients with unilateral attic cholesteatoma using three-dimensionally reconstructed high-resolution computed tomography images of the temporal bone. We determined the eustachian tube angle, eustachian tube length, sizes of the tympanic orifice of the eustachian tube, the pars flaccida, and the mastoid cavity, and distances of the pars flaccida and the tympanic orifice of the eustachian tube from the epitympanic roof. No significant differences were found between the normal and affected ears with regard to the size of the eustachian tube orifice, eustachian tube length or distances of the pars flaccida and the tympanic orifice of the eustachian tube from the epitympanic roof. By contrast, the mastoid cavity and the eustachian tube angle were significantly larger in the normal ears than in the affected ears [mean, 6.99 cm(3) (S.D.,4.9 cm(3)) vs. 1.28 cm(3) (0.81 cm(3)) and 16.7° (4.12°) vs. 13.89° (5.30°), respectively]. The pars flaccida was significantly smaller in the normal ears [1.07 cm (0.31 cm)] than in the affected ears [2.19 cm (0.77 cm)]. The inherent anatomy of the eustachian tube may be particularly important in the formation of attic cholesteatomas.

Effect of orifice and pressure of counter flow vortex tube

Effect of orifice and pressure of counter flow vortex tube

Using a Fabricated Forearm Free Flap for Simultaneous Reconstruction of Cervical Esophageal Circumferential Defect and Speech Function

Sir: Reconstruction of defects resulting from extensive oncologic surgery of the cervical aerodigestive track in advanced hypopharyngeal cancer is one of the most challenging procedures. In these patients, both functional swallowing and voice restoration are important.1 A 60-year-old man was admitted to our ward in February of 2005 because of a 5-cm nodule (squamous cell carcinoma) over the posterior pharyngeal wall. The stage of the tumor was T3N0M0. After ablative surgery, a 10-cm segmental defect of the cervical esophagus was noted. A fabricated forearm flap was designed based on the defect and the expected length of the phonation tube (Fig. 1). The flap was elevated using the standard method, and the skin paddles of the phonation tube and esophageal tube were repaired with fine Dexon suture to make it a tube (Fig. 2). The esophageal tube was used to replace the cervical esophageal defect. The phonation tube is placed as a curvilinear shape to reduce the amount of retrograde leakage (Fig. 3). The distal part of the phonation tube was placed beside the orifice of the permanent tracheostomy. Microanastomosis was performed with 10-0 nylon. The flap was monitored by the distal part of the phonation tube (Fig. 3).Fig. 1.: Drawing showing the design of the fabricated forearm free flap. The skin flap included two parts, the phonation tube (right) and the esophageal part (left), and was connected with tracheoesophageal puncture. a, 10-cm length of esophageal defect; b, 6-cm circumference of esophagus; c, 2-cm circumference of tracheoesophageal puncture; d, 8-cm circumference of oropharynx; e, 6-cm circumference of outer orifice of phonation tube.Fig. 2.: The esophageal part was rolled be a tube to replace the segmental cervical esophageal defect. The phonation tube (15 cm) was placed as a curvilinear shape. The distal part of the phonation tube was placed beside the orifice of the permanent tracheostomy.Fig. 3.: Transplantation of flap to the neck. The outer orifice of the phonation tube was placed beside the orifice of the permanent tracheostomy, where we could also monitor the flap.The fabricated forearm free flap survived uneventfully and the patient started his diet smoothly (liquid then solid diet) 3 weeks after the operation. The patient refused chemotherapy or radiotherapy. Two years later, he could still take a full diet without any difficulty. The phonation was obtained by diverting the expiratory airflow through the phonation tube to pass the tracheoesophageal puncture into the neoesophagus (Fig. 4) and evaluated by the ability of voice production, phonation efficacy, maximal phonation time per breath, loudness, and grading of wet voice. Speech intelligibility was evaluated by Hirose's classification,2 a five-point rating scale.Fig. 4.: Close-up view of the outer orifice of the phonation tube, 1 year after surgery.Regarding phonation and speech outcomes, the patient was able to produce sounds vocally 3 weeks after surgery. Eighteen months later, the phonation efficacy was 95 percent and the maximal phonation time was more than 6 seconds. The wet voice was graded as mild and the loudness was decreased mildly. The pitch was low and vocal fry sometimes occurred. Regarding speech outcome, the range of number counting was over 15. He could speak at least three syllables per breath. The speech intelligibility of this patient was classified as excellent. Two types of free flaps have been used for reconstruction of advanced cancer of the hypopharynx: the intestinal flap and the fasciocutaneous flap.3–5 Since the 1980s, the radial forearm free flap has been used for single-stage reconstruction of defects after laryngopharyngectomy,4 and it was proved to be a reliable reconstruction. Options for voice restoration with surgical procedures in pharyngolaryngectomized patients include tracheoesophageal puncture and tracheojejunal puncture, with or without prosthesis.1,5 In advanced hypopharyngeal carcinoma, the ileocecal valve in ileocolic flap reconstruction3 and the functional tracheopharyngeal shunt in jejunal flap reconstruction5 have also been used. In this report, besides the restoration of swallowing function, we used a phonation tube based on the same fabricated forearm free flap. After 2 years, this patient showed excellent swallowing and could take an ordinary diet. The phonation tube leakage was mild. The phonation efficacy was high and the speech outcome was satisfactory. Shih-Hsin Chang, M.D. Kwang-Yi Tung, M.D. Hung-Tao Hsiao, M.D. Department of Plastic and Reconstructive Surgery Mackay Memorial Hospital Taipei, Taiwan Jehn-Chuan Lee, M.D. Department of Otolaryngology Mackay Memorial Hospital Taipei, Taiwan Cheng-Chien Yang, M.D. Department of Otolaryngology Mackay Memorial Hospital, and Department of Speech and Hearing Disorders and Sciences National Taipei College of Nursing Taipei, Taiwan

Experimental performance of an automobile air conditioning system using a variable capacity compressor for two different types of expansion devices

An experimental R134a automotive air conditioning (AAC) system with a variable capacity compressor has been developed and equipped with various mechanical instruments. The system has the capability of using both a thermostatic expansion valve (TXV) and an orifice tube (OT) as an expansion device. The system has been tested by varying the compressor speed and temperatures of the air streams entering the condenser (Tcond,ai) and evaporator (Tevap,ai). Using experimental data, the performance parameters of the AAC system for TXV and OT operations have been evaluated. The results show that the cooling capacity usually increases with the compressor speed. However, the exergy destruction in the system also increases and the coefficient of performance (COP) decreases with the compressor speed. The cooling capacity and COP decrease on rising Tcond,ai, while they increase on rising Tevap,ai. The TXV operation usually yields slightly higher cooling capacity and COP and lower exergy destruction compared with OT operation.

Middle ear endoscopy and trans‐tympanic drug delivery using an interventional sialendoscope: a feasibility study in human cadaveric temporal bones

The aim of our study was to assess feasibility of using a 1.3mm semi-rigid interventional salivary endoscope for middle ear endoscopy and as a route for trans-tympanic delivery of medication in human cadaveric temporal bones. Five temporal bones harvested from human cadavers were examined. A 1.3mm diameter 0 degree. Marchal interventional sialendoscope equipped with an interventional channel (0.4 mm) and an irrigation/suction channel was used. Middle ear endoscopy was performed via endoscopic guided postero-inferior and antero-superior myringotomies. The round window niche (RWN) was easily identified, and a guide wire was placed within the RWN. Also, the Eustachian tube orifice was identified and cannulated with a guide wire. Access to the RWN was obtained via a postero-inferior myringotomy in all five temporal bones (100%). A guide wire could be navigated to the RWN without difficulty in all patients. The opening to the ET was visualized and could be cannulated with a guide wire in all patients where it was attempted (N=3). The 1.3 mm interventional sialendoscope allowed adequate visualization of the ET, middle ear space, and the RWN with interventional capabilities in a cadaveric model. Our result validates the feasibility of its use for trans-tympanic drug delivery. However, the proposed indication for the use of the sialendoscope needs to be evaluated in a clinical setting. Additional cadaveric and human studies are necessary to further investigate additional applications for its use in the field of otolaryngology.

Rhinosinusitis and Otitis Media: The Link with Adenoids

Rhinosinusitis and otitis media are very common diseases observed in pediatric patients. A clear association has been reported in literature between these two conditions. Even concordance in the microbiologic findings has been reported. These findings lead to a discussion in regard of a possible relationship between the two diseases and an eventual interference of another concomitant condition promoting this association. A key role in the linkage between rhinosinusitis and otitis media has been attributed to hypertrophic adenoidal tissue because of its mechanical obstruction of both choanae and Eustachian tube orifices. Recently some works in literature evidenced the presence of bacterial biofilms on adenoids and suggested a responsibility of bacterial biofilms in both chronic rhinosinusitis and otitis media. The debate is still active and more investigations are needed to clarify these topics.

Nasogastric Tube Position and Intragastric Air Collection in a Neonatal Intensive Care Population

For neonates receiving intensive care, nasogastric tube feeding is essential. Since nasogastric tube placement techniques are not well standardized and common verification methods can be unreliable, placement errors may lead to unsafe situations. In mechanically ventilated neonates and neonates on continuous positive airway pressure, malpositioning of the nasogastric tube may prevent excess air within the stomach to escape. In this study, we aimed to relate tube position to amount of air. The hypothesis was: the better the position of the tube, the smaller the amount of air in the stomach. A 1-year cohort of neonates in a level IIIc neonatal intensive care unit with a nasogastric tube. We retrospectively reviewed 326 radiographs and classified nasogastric tube position and gastric air. Descriptive statistics were used to describe demographic data. Kendal's tau statistic was applied to explore the relationship between nasogastric tube position and amount of gastric air. A Mann-Whitney U test was performed to confirm the differences in gastric air in neonates with Ch5 and Ch6 gastric tubes and neonates with Ch8 gastric tubes. One or both orifices of nasogastric tubes were in the esophagus in 7.1% of cases, tubes were curled up in the stomach in 35.3% of cases, and tube tips were beyond the pyloric sphincter in 5.5% of cases. Substantial or excessive air was found in 37.7% of cases. Kendal's tau value indicated that there was no significant correlation between nasogastric tube position and gastric air. The Mann-Whitney U value indicated that children with Ch5 and Ch6 gastric tubes had significantly more gastric air than children with Ch8 gastric tubes. Nasogastric tubes were malpositioned in nearly half of cases, and substantial or excessive air was found in more than one-third of cases. The hypothesis-the better the position of the tube, the smaller the amount of gastric air-was not confirmed by the data. However, a significant relationship was found between tube size and gastric air.

Single-Phase Microscale Jet Stagnation Point Heat Transfer

An investigation of the pressure drop and impingement zone heat transfer coefficient trends of a single-phase microscale impinging jet was undertaken. Microelectromechanical system (MEMS) processes were used to fabricate a device with a 67-μm orifice. The water jet impinged on an 80-μm square heater on a normal surface 200 μm from the orifice. Because of the extremely small heater area, the conjugate convection-conduction heat transfer process provided an unexpected path for heat losses. A numerical simulation was used to estimate the heat losses, which were quite large. Pressure loss coefficients were much higher in the range Red,o<500 than those predicted by available models for short orifice tubes; this behavior was likely due to the presence of the wall onto which the jet impinged. At higher Reynolds numbers, much better agreement was observed. Area-averaged heat transfer coefficients up to 80,000 W/m2 K were attained in the range 70<Red<1900. This corresponds to a 400 W/cm2 heat flux at a 50°C temperature difference. However, this impingement zone heat transfer coefficient is nearly an order-of-magnitude less than that predicted by correlations developed from macroscale jet data, and the dependence on the Reynolds number is much weaker than expected. Further investigation of microjet heat transfer is needed to explain the deviation from expected behavior.

Atmospheric pressure plasma jet: Effect of electrode configuration, discharge behavior, and its formation mechanism

Atmospheric pressure plasma jet (APPJ) can protrude several centers into the ambient air; therefore it holds remarkable promise for many innovative applications. The mechanism underlying this nonthermal discharge, however, remains unsettled that it has been often taken as resulting from dielectric barrier discharge or vaguely referred as streamerlike. We generated APPJ by using a quartz capillary tube with three distinct electrode configurations: conventional double dielectric electrodes for making dielectric barrier discharges, single dielectric electrode, and single bare metal electrode attached to the tube orifice. The jets generated by using the double dielectric electrodes were found consisting of three distinct parts and of different origins. The plasma jet starting from the active electrodes is essentially the propagation of streamers induced by corona discharge. With one single electrode, plasma jets can be generated in both downstream and upstream directions simultaneously; and more importantly at a significantly reduced voltage (peak-to-peak value from 3.6 kV on, at 17 kHz), this is particularly the case with the bare metal electrode configuration which also helps promote the jet velocity. The typical jet velocity at 104 m/s, the occurrence of a second streamer observed in the optical emission as well as the voltage and/or gas flow dependence of jet length can be reasonably accounted for by a streamer mechanism. These results may help steer the research into the underlying physics and will also facilitate a safer and more flexible implementation of this marvelous cold plasma source.

Measurement of airflow of air-conditioning in a car with PIV

In the present study, a model experiment is performed in order to clarify the airflow characteristics of a car cabin. In addition, this study provides high precision data for a benchmark test using the CFD (Computational Fluid Dynamics) analysis method. Initially, the study focuses on the ventilation mode that describes the flow field in the car cabin obtained from an experiment with PIV. The car cabin model is made of transparent acrylic resin and measures 1,450 mm × 700 mm × 900 mm, almost half the size of a real car, and was installed in a thermostatic chamber. In the experiment, the cabin model was controlled by an orifice tube and a pressure gauge in order to confirm the airflow rate. The PIV measurement was performed at a total of 18 regions within the section. The analyzed PIV data provides the mean velocity profile, the standard deviation distribution and the turbulence intensity distribution at each region.

Modified neural network correlation of refrigerant mass flow rates through adiabatic capillary and short tubes: Extension to CO 2 transcritical flow

This paper presents a modified dimensionless neural network correlation of refrigerant mass flow rates through adiabatic capillary tubes and short tube orifices. In particular, CO 2 transcritical flow is taken into account. The definition of neural network input and output dimensionless parameters is grounded on the homogeneous equilibrium model and extended to supercritical inlet conditions. 2000 sets of experimental mass flow-rate data of R12, R22, R134a, R404A, R407C, R410A, R600a and CO 2 (R744) in the open literature covering capillary and short tube geometries, subcritical and supercritical inlet conditions are collected for neural network training and testing. The comparison between the trained neural network and experimental data reports 0.65% average and 8.2% standard deviations; 85% data fall into ±10% error band. Particularly for CO 2, the average and standard deviations are −2.5% and 6.0%, respectively. 90% data fall into ±10% error band.

Round window fistula

A72-year-old woman was referred for a tympanic-mastoid cholesteatoma with erosion of the tegmen and right-sided complete deafness. Otoscopic examination showed near-complete atelectasis with a small tubal region perforation, scutum and facial canal erosion, absence of ossicles, and enlargement of the round window niche (Fig 1). The patient underwent canal-wall-down mastoidectomy under general anesthesia after providing written informed consent. Erosion of the round window promontory with endosteum sparing was observed after matrix removal (Fig 2). Temporalis fascia was used to protect the inner ear and facial nerve. Squama periosteum was used to obliterate the tubal orifice; bone dust was used to repair the tegmen tympani. The patient was discharged on the first postoperative day. She is well and free of disease 15 months later.

A Case of Inverted Papilloma Originating from the Middle Ear

Inverted papilloma (Schneiderian-type papilloma) involving the middle ear is extremely rare. Most of cases originate from the mucosa of the lateral nasal wall, extending into the paranasal sinuses and orbits. Inverted papilloma involving the middle ear has a high recurrence rate and a possibility of malignant change. We experienced a case of inverted papilloma of the middle ear secondary to congenital cholesteatoma surgery. A nine-year old male who was diagnosed with congenital cholesteatoma was treated with intact canal wall tympanomastoidectomy. Nine months later, he underwent a second look operation. In the second surgery, a 3 mm round pinkish mass which was located at the tympanic orifice of Eustachian tube was identified as inverted papilloma. There was no recurrence of cholesteatoma or inverted papilloma four months after the 2 nd operation. Korean J Otorhinolaryngol-Head Neck Surg 2009;52:781-3 Key WordsZZInverted papilloma·Middle ear·Cholesteatoma.

リニアモータ駆動・水静圧案内テーブルの開発 : テーブルシステムの設計・開発と静的特性(機械要素,潤滑,工作,生産管理など)

A linear-motor-driven table sustained by constant-flow hydrostatic water bearings which are free from environmental pollution is developed. The static characteristic of the developed table system is experimentally investigated. Since the constant-flow hydrostatic bearings needs no restrictor, such as orifice or capillary tube, blocking of the restrictor by bacteria, sludge, and rust of steel can be avoided. A miniature gear pump applied showed good constant flow performance for the hydrostatic bearing without pump pulsation. A simple one-side-recess type bearing is chosen for the system. In order to obtain high sustaining stiffness, preload is given to the bearings using attractive force of a core-type linear motor. The preload is effective in both vertical and horizontal directions by using the slant arrangement of the linear-motor magnet. The measured sustaining force is 4.5kN and static stiffness is 0.66kN/μm under bearing clearance h=16μm and flow rate Q=0.92mL/s.

Transoral Endoscopic Adenoidectomy

Objective. Adenoid curette guided by an indirect transoral mirror and a headlight is a simple and quick procedure that has already been in use for a long time, but this method carries a high risk of recurrence unless done by a well-experienced surgeon. The purpose of this paper was to evaluate the efficacy of transoral endoscopic adenoidectomy in relieving the obstructive nasal symptoms. Methods. 300 children underwent transoral endoscopic adenoidectomy using the classic adenoid curette and St Claire Thomson forceps with a 70∘ Hopkins 4-mm nasal endoscope introduced through the mouth and the view was projected on a monitor. Telephone questionnaire was used to follow-up the children for one year. Flexible nasopharyngoscopy was carried out for children with recurrent obstructive nasal symptoms to detect adenoid rehypertrophy. Results. No cases presented with postoperative complications. Only one case developed recurrent obstructive nasal symptoms due to adenoid regrowth and investigations showed that he had nasal allergy which may be the cause of recurrence. Conclusion. Transoral endoscopic adenoidectomy is the recent advancement of classic curettage adenoidectomy with direct vision of the nasopharynx that enables the surgeon to avoid injury of important structures as Eustachian tube orifices, and also it gives him the chance to completely remove the adenoidal tissues.

A Case of Middle Ear Lipoma

We present a case report of primary middle ear lipoma diagnosed in right ear of a 25-month-old girl with right otitis media. We identified injection and retraction at right ear drum. Impedance tympanometry of right ear was type B and temporal bone CT was suggestive of a congenital cholesteatoma. During the tympanoplasty, a mass of tissue obstructing the eustachian tube orifice was noted in the middle ear. We have treated a case of a lipoma that originated from the middle ear; only 5 such cases have been reported worldwide. (Korean J Otorhinolaryngol-Head Neck Surg 2009;52:273-5)

Multi-gene phylogeny of the pantropical subfamily Chrysophylloideae (Sapotaceae): evidence of generic polyphyly and extensive morphological homoplasy.

We present a molecular phylogeny of 26 out of the 28 currently accepted genera in the subfamily Chrysophylloideae (Sapotaceae) using parsimony, parsimony jackknifing, and Bayesian inference. A data matrix of 8984 characters was obtained from DNA sequences of seven chloroplast loci, two nuclear loci, indels coded as binary characters, and morphology. Our phylogenetic reconstruction suggests that Chrysophyllum, Pouteria, and Pradosia, as well as some sections within Chrysophyllum and Pouteria, are all polyphyletic. These taxa were previously described largely on the basis of unique combinations of states for a set of morphological characters. Mapping some of these characters onto one of the most parsimonious trees indicates that the symplesiomorphic flower in the subfamily was probably 5-merous, had stamens inserted in the tube orifice, staminodes, seeds with foliaceous cotyledons, exserted radicle, and endosperm. These characters have subsequently been lost multiple times and cannot be used as synapomorphies to support broad generic concepts. Despite the high degree of homoplasy some well-defined clades can be described on the basis of alternative character state combinations. Also, many of these well-supported clades appear to be restricted to particular geographical areas (e.g. all taxa in Australasia form a monophyletic group). Hence, we suggest that the segregate genera Aningeria, Malacantha, and Martiusella may ultimately be resurrected, and probably also Donella and Gambeya, but their circumscriptions are still unclear. One species, Chrysophyllum cuneifolium, may have originated from a hybridization event between continents where the maternal genome (cpDNA) comes from South America and the nuclear genome comes from Africa. © The Willi Hennig Society 2008.