Tube Orifice Research Articles

A study on the exit flow characteristics determined by the orifice configuration of multi-perforated tubes

A multi-perforated tube indicates the existence of multiple holes in various shapes on the surface of long cylinder-type or rectangular tubes, and the hole installed on the surface is called an orifice as it is relatively small in size, compared with the surface area of the tubes. In this study, flowrate distribution features and changes in discharge angle according to the blockage ratio resulting from the changes in the number of orifices and the thickness of multi-perforated tubes were investigated by means of analysis and experiment, targeting the multi-perforated tubes where rectangular orifices are installed on the both sides of square tubes. In addition, contraction coefficient and flow coefficient between orifices were analytically investigated. The more increase in blockage ratio of multi-perforated tubes, the more uniform flowrate distribution between orifices. The discharge angle becomes more and more perpendicular in the longitudinal direction of multi-perforated tubes as it gets closer to the end of orifices, exhibiting big differences at the entrance if blockage ratio is small. The more increase in the thickness of multi-perforated tubes, the more uniform flowrate distribution between orifices become as contraction coefficient increases. The flow coefficient distribution of orifices using the pressure at the entrance of the orifices of multi-perforated tubes increases in the longitudinal direction of the multi-perforated tubes, exhibiting values ranging from 0.66 to 0.68 as to BR = 0.893 ∼ 0.979.

Hypoxia-Inducible Factor and Vascular Endothelial Growth Factor Pathway for the Study of Hypoxia in a New Model of Otitis Media with Effusion

The hypoxia-inducible factor and vascular endothelial growth factor (HIF-VEGF) pathway in hypoxic conditions of the middle ear due to dysfunction of the eustachian tube is still unknown, but it is considered as one pathogenetic mechanism in otitis media. This study was designed to investigate the possible involvement of the HIF-VEFG pathway in otitis media with effusion induced by dysfunction of the eustachian tube. We adopted a soft palate approach to obstruct the orifice of the eustachian tube to establish otitis media in a rat model. Auditory evoked brainstem response and tympanometry were used as hearing function tests, hypoxia-related factors were examined by reverse transcriptase polymerase chain reaction (RT-PCR). The expression of hypoxia-related proteins was detected by Western blot and immunostaining. The model of otitis media with effusion was successfully induced by cauterizing the orifice of the eustachian tube. RT-PCR showed up-regulation of hypoxia-related factors in cauterized ears. Western blot and immunostaining showed that the expression of hypoxia-related proteins in cauterized ears was increased. Hypoxia-induced vascular proliferation and an increase in permeability may be one pathogenetic mechanism of otitis media due to dysfunction of the eustachian tube.

“Mucosal pocket” myringoplasty: a modification of underlay technique for anterior or subtotal perforations

PurposeChronic otitis media surgery is the most common procedure in otology in developing countries. Subtotal and total tympanic membrane (TM) perforation with inadequate anterior remnant is associated with higher rate of graft failure. It was the goal of this study to test the anatomical and functional outcomes of a modified underlay myringoplasty technique. Materials and methodsIn a prospective clinical study, 45 patients with subtotal or total TM perforation and inadequate anterior remnant underwent tympanoplasty (+/−mastoidectomy). The anterior tip of the temporalis fascia was secured in a mucosal pocket on the lateral wall of eustachian tube orifice. Data on graft take rate, preoperative and postoperative hearing status, and intraoperative findings were analyzed. ResultsWe achieved the graft success rate of 91.1%, without lateralization, blunting, atelectasia, or epithelial pearls. Approximately 24% patients had air-bone gap within 25 dB before intervention, which increased to 71% postoperatively (P < .001). ConclusionWe believe that this technique could be a convenient and suitable method for cases with subtotal or total TM perforation and inadequate anterior remnant.

Experimental investigation on flow modes of electrospinning

Electrospinning experiments are performed by using a set of experimental apparatus, a stroboscopic system is adopted for capturing instantaneous images of the conejet configuration. The cone and the jet of aqueous solutions of polyethylene oxide (PEO) are formed from an orifice of a capillary tube under the electric field. The viscoelastic constitutive relationship of the PEO solution is measured and discussed. The phenomena owing to the jet instability are described, five flow modes and corresponding structures are obtained with variations of the fluid flow rate Q, the electric potential U and the distance h from the orifice of the capillary tube to the collector. The flow modes of the cone-jet configuration involves the steady bending mode, the rotating bending mode, the swinging rotating mode, the blurring bending mode and the branching mode. Regimes in the Q-U plane of the flow modes are also obtained. These results may provide the fundamentals to predict the operating conditions expected in practical applications.

Zastosowanie endoskopii w operacjach ucha środkowego

Endoscopy is used in the middle ear surgery for above twenty years when decrease of cholesteatoma recurrence due to employing endoscope was revealed in comparison to standard microscopic only visualisation. Endoscopy may be the only way of visualisation in transcanal myringoplasty for the retraction pocket, stapedoplasty and transcanal ossiculoplasty. In canal wall up or second look tympanoplasty with mastoidectomy and posterior tympanotomy endoscopy may serve as an additional point of view supported the classical microscopical technique. In result of many manners in surgical treatment of chronic otitis media, there are very concept for endoscopy application. In the ENT Department at Medical University of Warsaw were performed 53 procedures by aid of endoscopy in period from September 2009 to December 2010. In this study there were 18 canal wall up tympanoplasties, 12 second look tympanoplasties and 8 canal wall down tympanoplasties. According to authors' experience endoscopy is the most useful in: There were three cases of cholesteatoma recurrence in the study found only due to endoscope support. In authors' opinion, the endoscopy is the useful tool in surgical treatment of chronic otitis media. Application of endoscopy during the middle ear surgery results in decrease in frequency of cholestatoma recurrence and increase in the effectiveness of the ossiculoplasty.

Laser Eustachian Tuboplasty

Laser Eustachian tuboplasty (LETP) with ablation of the epipharyngeal orifice of the Eustachian tube (ET) shows good results in clinical observation. However, to this day, there are no reports evaluating the surgical procedure with valid test methods. The purpose of this study was to test the effect of minimally invasive LETP by means of a pressure chamber ET function test. Prospective surgical trial. Tertiary and university hospital. Thirty patients with a history of ET dysfunction during pressure changes were examined. Minimally invasive LETP was performed with an 812-nm diode laser under local anesthesia as an outpatient procedure. The ET function was tested preoperatively and postoperatively by pressure chamber ET function test. Eustachian tube closing pressure (ETCP) was evaluated as a measure of the tissue pressure of the ET. In cases of a severely impaired ET function, a "blocked" pattern was evident, and no measurement of ETCP was possible. Before minimally invasive LETP, 17 patients showed a completely blocked pattern. Postoperatively, 13 patients of this group showed an improved ET function with a restored normal opening pattern (p < 0.001). The ETCP was reduced from 6.24 ± 3.46 mbar preoperatively to 4.06 ± 2.36 mbar postoperatively (p < 0.013). The results strongly indicate that the effect of minimally invasive LETP can be proven by measuring the ET function in a pressure chamber. Results must be interpreted in combination with clinical methods like Valsalva maneuver and tympanometry. Patients with ET dysfunction during pressure changes seem to benefit from the minimally invasive LETP.

Micro-bubble generation rate and bubble dissolution rate into water by a simple multi-fluid mixer with orifice and porous tube

A multi-fluids mixer by Sadatomi and Kawahara [1] is described as well as its performance as a micro-bubble generator for several trial products. In the experiments, air micro-bubble generation rate at water depths up to 3.6m and the dissolution rates of oxygen in air and carbon dioxide into tap water at 20°C were measured. In the analyses, the micro-bubble generation rate data could be well predicted by Sadatomi et al.’s model [2] by choosing suitable energy loss coefficients needed in the model, and the oxygen dissolution rates in tap water could be well correlated with Kawahara et al.’s model [3]. The detail of the multi-fluid mixer and its practical significances together with a result of experiments and analyses are reported in the present paper.

Experimental investigation on wall temperature of an air-breathing kerosene/air pulse detonation combustor with impingement cooling

Abstract The design of a practical pulse detonation combustor requires the components to be capable of enduring the severe thermal environment created by repetitive detonations. In the present study, an air-breathing kerosene/air detonation combustor was designed and fabricated. And the temperature distributions on the combustor liner were measured at various operating frequencies (from 10 Hz to 50 Hz) for both natural cooling and jet impinging cooling cases. The results show that the temperature distribution on detonation combustor liner under natural cooling mode is seriously non-uniform and the hottest region appears corresponding to where transition from deflagration to detonation occurs. The temperature rise amplitude corresponding to 10 Hz increase at higher operational frequency is smaller than that at lower operational frequency. As expected, the maximum temperature on detonation combustor liner is decreased as the increase of coolant flow rate. The impinging distance between jet orifice tube and circular liner is of important influence on the reasonable temperature distribution of a cooled combustor liner.

Pulsatile Tinnitus Arising from Aberrant Internal Carotid Artery at Nasopharynx

Pulsatile tinnitus arising from an aberrant internal carotid artery at the level of the nasopharynx is rarely found. We present a case of a 74-year-old woman complaining of pulsatile tinnitus in the right ear. The tinnitus was not audible by auscultation. Endoscopic examination revealed pulsating swelling of the nasopharyngeal wall on the right side. Computed tomography angiography of the head and neck region showed medial and superficial transposition of the right internal carotid artery at the level of the nasopharynx. The artery was located right next to the orifice of the Eustachian tube and coursed along the distal portion of the tube. The patient's perception of tinnitus was improved after explaining the cause of the tinnitus and reassuring her about the-condition.

A Case of a Child with a Lipoma of the Middle Ear and a Concomitant Chondroma of the External Auditory Canal

Journal of Case Reports in Medicine,2012,1,1,1-4.Published:June 2012Type:Case ReportAuthors:Tomoyasu Tachibana, Kazunori Nishizaki, Masayoshi Fujisawa, Yuya Ogawara, Yuko Matsuyama, Iku Abe, and Michihiro Nakada Author(s) affiliations:Tomoyasu Tachibana,1 Kazunori Nishizaki,2 Masayoshi Fujisawa,3 Yuya Ogawara,1 Yuko Matsuyama,1 Iku Abe,1 and Michihiro Nakada4 1Department of Otolaryngology, Himeji Red Cross Hospital, 12-1 Shimoteno 1-Chome, Himeji City, Hyogo 670-8540, JAPAN. 2Department of Otolaryngology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1, shikata-cho, kita-ku, Okayama City, Okayama 700-8558, JAPAN. 3Department of Pathology, Himeji Red Cross Hospital, 12-1 Shimoteno 1-Chome, Himeji City, Hyogo 670-8540, JAPAN. 4Nakada ENT Clinic, 2-2-20, Shirakuni, Himeji City, Hyogo 670-0808, JAPAN. Abstract:The case of a 2-year-old boy with a right middle ear lipoma and a concomitant chondroma of the left external auditory canal is presented. The patient’s preoperative diagnosis was cholesteatomas of the right middle ear and left external ear canal. A right-sided epitympanotomy was performed. A lump of fatty tissue in the right anterior middle ear cleft that obstructed the Eustachian tube orifice was found. The white mass in the left external auditory canal, which easily separated from the tympanosquamous fissure of the temporal bone, was excised with a Rosen needle. Histopathologic examination revealed a lipoma of the right middle ear and a chondroma of the external ear canal. No cases of concomitant lipoma and chondroma have been previously reported. In the present case, the middle ear lipoma could be classified as a congenital anomaly because of its association with a contralateral side chondroma, which would be a choristoma. Keywords:Chondroma; Choristoma; LipomaView:PDF (1.3 MB) PDF Images Figure 1: Macroscopic findings of the right (left panel) and left (right panel) ear during the operation. Otoscopy reveals an opacity in the anterosuperior quadrant of the right membrane and a flat, smooth, white mass in front of the short process of the malleus on the superior wall of the left bony external auditory canal.

Temporal Bone Study of the Internal Carotid Artery at the Tympanic Orifice of Eustachian Tube

Temporal Bone Study of the Internal Carotid Artery at the Tympanic Orifice of Eustachian Tube

Detecting Reflux in Adults with Eustachian Tube Dysfunction

Objective: 1) Ascertain whether adult patients with Eustachian tube dysfunction (ETD) have a higher incidence of reflux into the nasopharynx compared with controls. 2) Utilize recent advances in pH probe technology to detect acidity at the Eustachian tube orifice for direct comparison. Method: A prospective study was performed on 38 adult patients in an outpatient setting between November 2009 and February 2011. Seventeen patients with Eustachian tube dysfunction and 21 control subjects had a Dx-pH probe (Restech, San Diego, California 2006) placed near the torus tubarius in the posterior nasopharynx for 24 hours. Results: The average pH value obtained from the nasopharynx of adults with no history of ETD was 7.03 (range, 6.10-7.92; SD, 0.69). In comparison, the average pH for patients with ETD was 6.90 (range, 5.33-8.06; SD, 0.77). This P value for this difference was .48. The average number of reflux events for subjects was 0.55 events over a 24-hour period for controls and 2.1 for patients with ETD. Decreases in pH were considered reflux events if the pH dropped below 5.5 while in the upright position or below 5.0 in the supine position. Conclusion: By utilizing a novel pH probe that allows detection of acidity in a non-liquid environment, a comparison of nasopharyngeal pH between control patients and those with ETD was performed. A trend toward higher numbers of reflux events was found in patients with ETD when compared to control subjects.

Multidisciplinary Practical Guidelines for Gastrointestinal Access for Enteral Nutrition and Decompression From the Society of Interventional Radiology and American Gastroenterological Association (AGA) Institute, With Endorsement by Canadian Interventional Radiological Association (CIRA) and Cardiovascular and Interventional Radiological Society of Europe (CIRSE)

J INTRODUCTION Tube feeding has been practiced for more than 400 years (1). In addition to feeding, gastrointestinal (GI) access can be used for decompression in cases of enteral obstruction. Temporary access can be achieved with a nasogastric (NG), oral gastric (OG), nasojejunal (NJ), or oral jejunal (OJ) feeding tube. These tubes can be placed “blindly” at the bedside, with the use of image guidance (eg, fluoroscopy, ultrasound), or with the use of endoscopic guidance. Unfortunately, natural orifice tubes often fail because of clogging as a result of their relatively small diameter or inadvertent dislodgement (2). More permanent enteral access can be obtained

Intranasal delivery of drugs to eustachian tube orifice

Intranasal medication administration which aims to deliver to the eustachian tube orifice has been adopted for the management of a number of otological conditions, acting via a reduction in tubal oedema and improved ventilation. Evidence for the optimal head position for such drug administration is limited. We compared four different positions and also assessed spray versus drop formulation, to determine optimal delivery conditions. Prospective, five-period, cross-over study using methylene blue dyed saline in a drops or spray container. Five healthy volunteers tested the Mygind, Ragan, Mecca and 'head back' head positions. Nasal spray drug delivery in the most effective head position was then compared with drops drug delivery (administered in the head back position). Intranasal delivery was assessed photographically using a 30° rigid naso-endoscope. Maximal nasal drops delivery was achieved with the Mygind and Ragan positions. Drops were more successful than spray in reaching the eustachian tube orifice. The Mygind and Ragan positions are best for eustachian tube orifice drug delivery, and drops preparations are better than spray preparations.

Numerical analysis of stirling type pulse tube cryocoolers

A one-dimensional finite volume discretization method is proposed and is implemented as a computer program for the modeling of a family of stirling type Pulse Tube Cryocoolers (PTC). The set of unsteady, one-dimensional, viscous compressible flow equations are written in a general form such that all, porous and non-porous, sections of the PTC can be modeled with these governing equations. In present work, temperature dependency of thermo-physical properties are taken into account as well as the heat transfer between the working fluid and the solid parts, and heat conductions of the gas and solid. The simulation tool can be used to model both the inertance tube type and the orifice type cryocoolers equipped with regenerators made up of different matrix constructions. The PTC might have an arbitrary orientation with respect to the gravitational field. By using the computer program, an orifice type and an inertance tube type pulse tube cryocooler are simulated. Diameter of the orifice and length of the inertance tube are optimized in order to maximize the coefficient of performance. Furthermore, the cooling power of the two types is obtained as a function of the cooling temperature. The behavior of thermodynamic parameters of the inertance tube PTC is investigated. Mean cyclic values of the parameters are presented.

Experiments on Dicing Monocrystalline Silicon Wafer Using Micro Abrasive Water Jet

The experiments on dicing monocrystalline silicon wafer using micro abrasive water jet turning were performed. A specifically designed water jet machine tool with four axes was developed and a specially designed cutting head has developed, in which the inside diameter of orifice and focusing tube is f125 mm and f500 mm respectively, while the silicon carbide solid abrasives with average diameter of 25-100 mm was used. In order to control the flow rate of micro abrasives precisely, an abrasive feed system with auger mechanism driven by DC motor reducer was used. The diameters of monocrystalline silicon bars are around 50 mm. Two basic turning methods, i.e. turning with stationary jet and turning with moving jet were applied. The preliminary experimental results such as kerf width, wafer thickness, surface quality etc. were analyzed. It was found that micro abrasive water jet can be used to precisely turn brittle materials like monocrystalline silicon. The turned wafer with thickness of 1 mm above could be achieved. A thinner wafer less than 1 mm is difficult to obtain during experiments because of cracking or chipping. Experiments demonstrate that the wafer surface has macro stripping characteristics similar to linear cutting. It was observed that there is less waviness and smooth surface on the turned wafer when with moving jet. And it depends greatly on the water jet pressure, feed rate of the jet, rotation speed of silicon bar, abrasive particle size as well as flow rate of abrasive. The detailed analysis indicates that the surface roughness of turned wafer with moving jet is around Ra 1.5-5.6 μm, while that of turned wafer with stationary jet is around Ra6.3 μm, when other conditions are same. The results show that surface quality turning with moving jet is obviously better than that of stationary jet. Smaller surface roughness of turned wafer could be obtained when finer abrasive is used. The experiment shows also that the wafer is typically tapered with either the stationary jet or moving jet. There is a concave on the turned surface when feed rate of the jet is too low or dwell time is too long. This is attributed to the jet rebound from one face to the other. Therefore there is an optimizing rotational speed during turning. This study indicates that dicing mono crystalline silicon wafer using micro abrasive water jet turning has potential application in semiconductor industry.

Characteristics of R-123 two-phase flow through micro-scale short tube orifice for design of a small cooling system

We present a new discharge coefficient correction method for the orifice equation for R-123 two-phase flows. In this method, an evaporator is mounted after the orifice as a vapor refrigeration cycle, and the evaporator is used to measure the quality of downstream flow through the orifice. Quality is estimated from the measured temperature and pressure of the evaporator inlet and outlet, respectively, instead of by direct measurement of quality. The condition of upstream flow of the orifice is the liquid state at 3 bar and 60 °C. The liquid flow is changed to two-phase flow after passing through the orifice. Orifice diameters of 300, 350, 400, and 450 μm are used for the experiment, and the results are analyzed. Experiments are conducted for various conditions of flow rate between 20 and 70 ml/min and for cooling loads of 60, 80, and 100 W. The results show that the quality of flow downstream from the orifice can be calculated using the enthalpy difference between the inlet and outlet of the evaporator. An equation to determine the discharge coefficient is formulated as a function of quality. We expect that these results can be used to help design a small cooling system.

Tympanic membrane and nasopharyngeal orifice of Eustachian tube of former leprosy patients

Tympanic membrane and nasopharyngeal orifice of Eustachian tube of former leprosy patients

A guinea pigs model of otitis media with effusion caused by reversible Eustachian tube obstruction

To develop a animal model for acute otitis media with effusion (OME). In 22 guinea pigs, the left nasal orifice of Eustachian tube was approached via a transpalatal incision and obstructed with polyvinyl acetal material. Right ears were set as the control. Then all the ears were evaluated by otomicroscopy every day. Seven, 14 and 21 days after the intervention, six guinea pigs were killed for histologic study. Of the 22 guinea pigs included in this study, 20 ears (90.9%) were found to have effusion 3 - 7 days after the operation, two cases were excluded for purulent otorrhea 10 days postoperatively. The epithelium initially developed hyperplasia, and the submucosa showed vascular and lymphatic dilatations with inflammatory cells infiltration. None of the contralateral control ears had evidence of disease by otomicroscopic examination and histologic study. This experimental methods provoked reproducible pathologic characteristics similar to those for otitis media with effusion.

An insertable orifice tube for in situ contamination counts of solutions in opened ampoules and vials using the Coulter Counter.

An insertable orifice tube for in situ contamination counts of solutions in opened ampoules and vials using the Coulter Counter.