Gauge Tubes Research Articles

Performance Analysis of Emergency Ventilator #BPPT3S-LEN for In-Hospital Use

Covid-19 is a global pandemic that originated in Wuhan, China in 2019. It spread very fast around the globe. Many countries suffer from this disease. About 532.2 million people were confirmed and 6.3 million patients were reported dead globally. People infected by this disease will suffer from breathing problems, ranging from light problems to respiration failure. Mechanical ventilators are commonly used to treat patients with respiration failure. However, the increasing number of Covid-19 patients staying in the hospitals, caused the hospitals to lack mechanical ventilators. The emergency ventilator was a choice need to be developed to respond to the lack of mechanical ventilators in the hospitals. It is easy to develop, electronics and medical components available in the local market. Emergency Ventilator #BPPT3S-LEN is an automatic BVM-based resuscitator. This medical device was developed based on the Emergency Use Ventilator Design Guidance of AAMI/CR501:2020 of the USA and MHRA of the UK. It consists of a mechanical part for squeezing, airbag, breathing circuit, pressure gauge, one-way valve, relief valve, flow sensor, PEEP valve, mask or endotracheal tube. Ventilation parameters need to be set in this device including tidal volume, respiration rate, inspirations/expiration time ratio, and PEEP (positive end-expiratory pressure). Measured parameters were tidal volume, respiration rate, peak inspiratory pressure, inspiration/expiration time ratio. Alarm systems were set for maximum inspiration pressure, minimum battery voltage, AC power failure. Self-calibration software was installed in this device. Medical doctors tested about 5 emergency ventilators in regional public hospital RSUD Dr. Saiful Anwar Malang, Indonesia. It was reported that the devices gave better results than manual bagging for measurement results of tidal volume, respiration rate, and peak inspiratory pressure.

Методика вимірювання параметрів тиску та розрідження

Методика вимірювання параметрів тиску та розрідження

Investigation of statistical parameters of the evolving wind wave field using a laser slope gauge

Statistical parameters of water waves generated by wind in a small scale facility are studied using extensively a Laser Slope Gauge (LSG), in addition to conventional measuring instruments such as a wave gauge and Pitot tube. The LSG enables direct measurements of two components of the instantaneous surface slope. Long sampling duration in a relatively small experimental facility allowed accumulating records of the measured parameters containing a large number of waves. Data were accumulated for a range of wind velocities at multiple fetches. Frequency spectra of the surface elevation and of the instantaneous local slope variation measured under identical conditions are compared. Higher moments of the surface slope are presented. Information on the waves’ asymmetry is retrieved from the computed skewness of the surface slope components.

各種断面形状押出形材の回転引き曲げ加工限界

Extruded aluminum alloy sections are advanced materials composed of lightweight structural members. A secondary forming process such as bending is required when these materials are utilized for practical use. Some undesirable deformations such as flattening distortion, wrinkling and splitting occur during the bending process of light gauge tubes. Thus, the working limits for the shape and dimension of such sections are very important in designing lightweight constructions. In this study, a square tube, a square tube with a lateral direction rib, a square tube with a radial direction rib, an asymmetric channel, a hat channel and a channel were used in rotary draw bending with axial tension. Mandrels were selected to match the characteristics of the sections. The working limits for some thickness ratio and materials such as A6061S-O, A6061S-T6, A6063S-O and A6063S-T5 were introduced. This study shows that a working limit that depends on the type of cross section and on thickness ratio, and the application of axial tension to the draw bending of light gauge tubes are very effective in preventing wrinkling in rotary draw bending.

Bayard-Alpert ionization gauge sensitivity for C7F14

Various empirical methods are applied to estimate the Bayard-Alpert ionization gauge relative sensitivity for C7F14. These values are compared to a measured value obtained by calibrating the ion gauge tube pressure sensor against a capacitance manometer.

Encapsulating peritoneal sclerosis-a life-threatening condition treated successfully with adhesiolysis and Jones tube insertion.

Sir, Encapsulating sclerosing peritonitis, a life-threatening abdominal disease, is characterized by the formation of multiple fibrous adhesions. This leads to a ‘cocoon’ of fibrous tissue, encapsulating either the small or whole bowel— causing intestinal obstruction. It was first recognized as a complication of peritoneal dialysis (PD) in 1980 [1], where it usually presents as small bowel obstruction, ascites or ultrafiltration failure. It is thought to be related to both duration of catheter use and peritoneal membrane transport characteristics, being more common in ‘fast transporters’ [2]. Convincing evidence of cure has come only from adhesiolysis, which releases the fibrous adhesions [1]. Intraluminal stenting after adhesiolysis for small bowel obstruction was first described by White in 1956. Despite the technique being modified by Munro and Jones in 1978 [3], it has never gained widespread popularity in the UK. The major complication of surgery is a high recurrence rate. In one series, 11/47 patients (23.4%) experienced recurrence, 10 undergoing a second operation, and 4 requiring a third operation [4]. The mortality is uncertain, with a wide range reported (2–56%). The rationale for our technique was to further reduce mortality and recurrence rate, and provide an alternative to drug treatments (e.g. immunosuppression) whose side effects carry considerable morbidity. A 69-year-old woman, on PD for 10 years for ERF, was converted to haemodialysis in January 2003 due to recurrent peritonitis. In June 2003, she presented with recurrent ascites. An abdominal CT scan (below) suggested multiple encapsulating loculated collections in the abdomen. TPN was given for 6 weeks before surgical intervention. In September 2003, a laparotomy revealed encysted dense adhesions and a large pseudocyst in the pelvis entrapping the bowel. The adhesions were released and a Jones tube was placed through the entire length of the gastrointestinal tract. A Jones tube is a 3 m (18 gauge) tube with side perforations and a balloon at the distal end. During surgery, the tube was advanced via the nasogastric route through the entire length of the bowel and the distal end came out of the rectum. The balloon was inflated and the small bowel arranged in orderly fashion, so that even if fibrosis did occur, the bowel did not get entrapped. This was left in situ for 1 week, with TPN and haemodialysis continuing. She was discharged 7 months later and is currently well on haemodialysis, with no evidence of recurrence. In ERF patients, encapsulating peritoneal sclerosis is a rare disease and is usually a long-term complication of peritoneal dialysis. This type of surgery has to be slow (4 h in our case) and careful, releasing bowel from fibrous bands all along its length. Adhesiolysis with intraluminal stenting should be considered as an option in the treatment of encapsulating peritoneal sclerosis. Conflict of interest statement. None declared.

熱間サイジングミルにおける小断面極厚肉角形鋼管成形の有限要素解析

Ultra heavy gauge steel square tubes have been required as columns to promote the beautiful design of such as glass-faced buildings and shopping arcades. There have been some methods of manufacturing square columns, but manufacturing heavy gauge tubes was difficult in either method. Then hot forming was suggested as a method of manufacturing heavy gauge tubes by reshaping round cross-sectional mother pipe into square shape. Sharpness of the corners and flatness of the sides are both essentially required. Rigid plastic finite elemental method was applied to simulate the deformation of the material during the hot forming, and influence of forming condition on the both requirements was discussed. 2-roll-type hot sizing mill was applied as the instrument of the hot forming. The simulations were carried out in 4 cases with difference of total reduction or distribution of reduction at each stand. The square tube was experimentally formed under one of the above 4 cases.The calculated result was in a good accordance with the experimental result. The shapes of corners become sharper as growth of the total reduction. The sides become flatter as the reduction at the final stand is smaller. Large total reduction with small reduction at the final stand is recommendable to satisfy the both of sharp corners and flat sides.

Drosophilatalin and integrin genes are required for maintenance of tracheal terminal branches and luminal organization

Epithelial tubes that compose many organs are typically long lasting, except under specific developmental and physiological conditions when network remodeling occurs. Although there has been progress elucidating mechanisms of tube formation, little is known of the mechanisms that maintain tubes and destabilize them during network remodeling. Here, we describe Drosophila tendrils mutations that compromise maintenance of tracheal terminal branches, fine gauge tubes formed by tracheal terminal cells that ramify on and adhere tightly to tissues in order to supply them with oxygen. Homozygous tendrils terminal cell clones have fewer terminal branches than normal but individual branches contain multiple convoluted lumens. The phenotype arises late in development: terminal branches bud and form lumens normally early in development, but during larval life lumens become convoluted and mature branches degenerate. Their lumens, however, are retained in the remaining branches, resulting in the distinctive multi-lumen phenotype. Mapping and molecular studies demonstrate that tendrils is allelic to rhea, which encodes Drosophila talin, a large cytoskeletal protein that links integrins to the cytoskeleton. Terminal cells mutant for myospheroid, the major Drosophila beta-integrin, or doubly mutant for multiple edematous wings and inflated alpha-integrins, also show the tendrils phenotype, and localization of myospheroid beta-integrin protein is disrupted in tendrils mutant terminal cells. The results provide evidence that integrin-talin adhesion complexes are necessary to maintain tracheal terminal branches and luminal organization. Similar complexes may stabilize other tubular networks and may be targeted for inactivation during network remodeling events.

The effect of ambient temperature on the sensitivity of hot-cathode ionization gauges

We measured the sensitivities of five hot-cathode ionization gauges for ambient laboratory temperatures between 23 and 31 °C. All of the ionization gauges exhibited very similar behavior, and the sensitivity could be adequately modeled with a linear function of temperature. The slopes of the fits were smaller than one would expect due to changes in the calibration chamber number density. The thermal transpiration effect, due to local heating of the gauge structures, can account for this, and a characteristic gauge tube temperature can be inferred from the temperature dependence of the sensitivity. A recent comparison of the high vacuum standards of several National Metrology Institutes (NMIs) was performed over the range of 10 −6–10 −3 Pa using hot-cathode and spinning rotor gauges as transfer standards. Among the participants, laboratory temperatures varied by as much as 5 °C. It is necessary to know how laboratory temperature affects the sensitivity of the hot-cathode transfer standards (spinning rotor gauges explicitly account for the gas temperature) so that individual laboratory results can be corrected to a common temperature.

Cleaning a Cold Cathode Gauge Tube

Abstract This topic appeared on the MSA list server In December 2002 and January 2003. While cleaning my gauge tube recently, I documented the steps. In this article I describe cleaning a Varian 524-2 gauge tube. There are a number of other cold cathode and penning style gauge tubes on the market, Edwards CP-25 (old penning), CVC GPH-001A(old cold cathode), Pfeiffer IRK 250 (new cold cathode) to name a few. The cleaning steps are very similar. Consult the instructions that came with the gauge tube or visit the vendor's websites.

Stable cancellation of x-ray errors in Bayard–Alpert gauges

X-ray induced emission of electrons from the ion collectors of Bayard–Alpert gauges has long been recognized as a cause of falsely high readings at low pressures. Less well known is the existence of a reverse x-ray effect leading to a superimposed, but usually smaller, error signal in the opposite direction. First explained by Redhead and others in the 1960s as being caused by photoemission from the gauge envelope, this phenomenon was immediately recognized as potentially useful in cancelling the forward x-ray effect. Although promising experimental results were obtained with special gauge tubes, these early researchers concluded that the cancellation process was too unstable to be of any practical use. We report the results of an attempt to stabilize the cancellation process by the use of identical materials at the two photoemission sites. Experimental Bayard–Alpert gauge tubes were built with gold coatings on the insides of the gauge envelopes and on the surfaces of the ion collectors. The envelope coatings were operated at approximately 15–25 V below the potential of the ion collector. Stable reduction of the x-ray errors by a factor of more than 20 has been demonstrated. Short-term improvements by a factor of 100 have been achieved. Useful improvements have also been observed in sensitivity and in stability at high pressures. Results of long-term stability tests at pressures in the 10−10 Torr range are described.

Partial rejuvenation of Bayard–Alpert ionization gauge tubes

We describe a simple procedure for the partial restoration of Bayard–Alpert ionization gauge tubes that have been contaminated by a combination of mechanical and silicone diffusion pump oil vapors. The method consists in filling the tube with 1 M NaOH, immersing it in a hot water bath (>80 °C, ca. 1 h), thorough rinsing with deionized water and reagent acetone, and air drying. This procedure was tested on nine inoperable gauges; after restoration seven of the gauges read within a factor of 2 of a new gauge.

A primary standard high vacuum calibration station for industrial applications

The Metrology Laboratory at Lockheed Martin Missiles & Space in Sunnyvale, CA, has developed a primary standard high vacuum calibration station. Maintaining an in-house capability for calibrating Bayard–Alpert gauge tubes and spinning rotor gauges (SRGs) at the primary level eliminates the need for external sources of calibration. This not only significantly reduces costs but also provides for continuous monitoring of the reference standards used to support research programs and manufacturing processes. A constant volume, pressure drop flowmeter is used to generate known pressures in a vacuum chamber partitioned by an orifice of calculable conductance. Data are presented which show vacuum chamber pressure to be directly proportional to flowmeter pressure drop in the three decades of vacuum spanned by the SRGs (10−3–10−6 Torr). Using a SRG calibrated at the National Institute of Standards and Technology, the proportionality constant is determined and shown to agree well with the constant calculated from system fixed parameters and measured pressure ratios. A new design of flowmeter is discussed. An estimate of when the system will be fully utilized as a primary reference will be made.

ABC of general surgery in children. Surgically correctable causes of vomiting in infancy.

Surgically correctable causes of vomiting in infancy are unusual, but an awareness of this possibility is important in order to prompt appropriate referral and management. It is possible to consider the various conditions by the age of the infant. #### Surgically correctable causes of vomiting in infancy Infants up to one week old Infants up to one month old Infants up to one year old #### Clinical features suggesting a surgically correctable cause of vomiting Infants with oesophageal atresia may well present on the postnatal ward or delivery suite with regurgitation of saliva, although clearly this is not strictly vomiting. Such babies are characteristically described as mucousy or bubbly, and there may have been a history of maternal polyhydramnios. The clinical diagnosis can be confirmed by attempting to pass a large nasogastric tube (8-10 French gauge) and then taking an x ray picture of the chest. Smaller gauge tubes may well coil in the upper pouch. Radiograph showing nasogastric tube curled in upper pouch of oesophageal atresia (arrow) and large isolated stomach bubble caused by an associated duodenal atresia. Almost all upper gastrointestinal atresias such as duodenal or jejunal atresia present on the first or second day of life. The key clinical feature is vomiting of bile, and this certainly requires a surgical review. Polyhydramnios may again have been a feature during pregnancy, and in some infants prenatal vomiting of bile may mimic meconium stained liquor. Even the absence of bile from the vomit does not exclude duodenal atresia, as some 15% of even complete duodenal occlusions are supra-ampullary. Unlike other causes of a high intestinal obstruction, up to 30% of infants with duodenal atresia also have Down's syndrome. These can be less clear cut, and successful feeding may become established with perhaps only occasional …

Technical report: intubation fluoroscopy times using a new enteroclysis tube

Initial experience with a new 10 F gauge version of the Nolan enteroclysis tube is reported. The mean intubation fluoroscopy time in 80 patients was 1.53 min. The more flexible smaller gauge tube is ideal for rapid duodenal intubation via the nasal route.

Performance of the cold cathode gauges in a high and misaligned magnetic field

Cold cathode gauge tubes without their permanent magnets will be used to monitor the vacuum systems of a muon storage ring, presently under construction at Brookhaven. The fringe field of the storage ring’s superconducting magnet will be used to sustain the gauge discharge. Three commercial cold cathode gauges, a Penning type, a grounded Penning and an inverted magnetron, have been studied for their suitability under this high and misaligned magnetic field. Using an electromagnet, the discharge intensities of these gauges have been measured at pressures from 10−8 to 10−5 Torr, magnetic fields from a few hundred Gauss to 15 kG, and alignment angles from 0° to 50°. The discharge intensity of the Penning gauge increases with increasing magnetic field misalignment and decreases gradually with increasing pressure and magnetic field. At small misalignment, the discharge intensity of the grounded Penning decreases with increasing magnetic field, and if the misalignment is large, it drops off abruptly at high magnetic field. The discharge intensity of the grounded Penning peaks around 1×10−6 Torr if the magnetic field is low; and at a high magnetic field, it drops off gradually with increasing pressure. At lower pressures, the discharge intensity of the inverted magnetron gauge remains fairly constant with an increasing magnetic field, but decreases with increasing magnetic field at higher pressure ranges. Its discharge intensity also decreases rapidly with increasing misalignment.

A linearly displayed ionization-gauge controller implemented with automatic range switching

A vacuum ionization-gauge controller using a CMOS bilateral switch for automatic range selection is described. It provides a linear analogue pressure display in the 10-3-10-8 mbar range. The use of a fast stabilization loop in the filament current supply gives a wide range of emission current control which fits various kinds of gauge tubes. The application of a standard integrated circuit greatly simplifies the electronic system and makes the gauge meter very stable, compact and of low cost.

Using microchannels to improve the performance of vacuum technology instrumentation

Many instruments used in vacuum technology for the measurement and diagnosis of the gas content of systems use electrons and ions directed by electric and magnetic fields. Examples include mass spectrometer leak detectors, residual gas analyzers, and ion gauge tubes. Microchannel technology, originally developed to implement night vision devices for the military, can be used to make beams of electrons and ions visible. This technology is very useful in the development and improvement of devices that depend on the electric and magnetic optics to form and guide such beams. The development of a new tube for a leak detector provides a good example of the application of this technology. The basic structure of microchannel devices requires special vacuum enclosures and electrical circuitry; some examples used in the development of the new tube are presented, along with photographs of ion beam images. The images demonstrate a previously unrecognized focusing phenomenon, a good example of the utility of the approach.

Vacuum

Varian has introduced a new innovation in vacuum measuring equipment – the multigauge. Multigauge is microprocessor-driven and allows users to power-up and control various combinations of vacuum gauge tubes using a single control box. Multigauge can accommodate combinations of up to three ionisation gauges (UHV, Bayard-Alpert or Penning) and two thermocouple boards, each board capable of driving up to four gauge tubes. All gauge tubes are poweredup and function simultaneously, and with its multi-colour front panel display and key pad, total system control including set-points, auto-filament turn-on, degas and many other features, can be achieved with this user-friendly vacuum controller. T1

Neonatal pneumothorax drainage systems: in vitro evaluation.

We studied, in vitro, different commercially available components for pneumothorax drainage, i.e. drainage tubes, Heimlich flutter valve and vacuum control units. The drainage of a pneumothorax by a drainage tube was, as expected, directly dependent on Poiseuille's law and was influenced more by diameter than length. Of practical importance, a size 6 French gauge tube, used for the very small newborn, may not efficiently evacuate a pneumothorax due to a large air leak. The Heimlich flutter valve, though useful clinically, adds to the resistance of the system especially if fluids accumulate in the valve. All vacuum control units, adaptations of the basic three- or four-bottle pleural drainage system, functioned adequately but simple changes in construction may increase the safety of some of these systems.