L-shaped Tube Research Articles

Experimental investigation of hydrogen addition in the intake air of compressed ignition engines running on biodiesel blend

This study investigates the effects on the performance of a diesel generator set at constant electric power of 2.43 kW (approximately 60% nominal engine load condition) and rotation at 3600 rpm operating with a 7% biodiesel-diesel blend (B7) and being doped with hydrogen into the intake air. Hydrogen was injected continuously into the engine intake manifold at different mass concentrations of 2, 6, 8 and 10% of the total fuel mass (B7 + hydrogen) which represents energy fractions of 5, 15, 20 and 24% of total fuel energy. To this, a small L-shaped tube installed at the center of the pipe was used. It is anticipated that the intake air fluctuations at that location, due to opening and closing the intake valve, allows a rapid mixture of hydrogen and air. Due to the addition of hydrogen the total amount of energy in the fuel (B7 + hydrogen) introduced into the engine was increased, so that the engine speed tends to increase, but this was prevented by the governor of the fuel injection pump which decreases the amount of B7 injected until the working frequency of the generator was 60 Hz. The test results showed a reduction in the specific fuel consumption as a function of the increase of hydrogen concentrations. Likewise, CO2, CO and HC emissions decreased proportionately as the hydrogen concentration was increased. On the other hand, the emissions of nitrogen oxides (NOx) increased due to the increase in the average temperature inside the cylinder. There was also an increase in the peak pressure and in the heat release rate inside the cylinder, since B7 ignition delay was reduced due to the increase in hydrogen content.

Genetic improvement of host-seeking ability in the entomopathogenic nematodes Steinernema carpocapsae and Heterorhabditis bacteriophora toward the Red Palm Weevil Rhynchophorus ferrugineus

Rhynchophorus ferrugineus (red palm weevil) is highly susceptible to infection by the entomopathogenic nematodes Steinernema carpocapsae and Heterorhabditis bacteriophora. However, to reach and penetrate the insect in its habitat with good efficacy, the nematode infective juveniles (IJs) need to move through the tunnels bored by the feeding insect larvae in the tree trunk. We used a genetic-improvement approach to enhance host-seeking ability (HSA) of these nematode species’ IJs. The IJs were allowed to move through a 45-cm L-shaped tube toward red palm weevil larvae. The IJs which reached within 5cm of the insect larvae were collected and reared. Selection cycles were repeated 15 times. The HSA of S. carpocapsae IJs was enhanced 11-fold (from 3.7 to 39.8% of all IJs reaching proximity of the larvae) and 8.5-fold (from 2.3 to 19.7%) for H. bacteriophora after 10 cycles of selection. Further selections (cycles 11–15) had no significant impact on improving HSA. HSA of the selected lines was highly specific to R. ferrugineus larvae. Selection for improved HSA also enhanced infectivity to R. ferrugineus, Galleria mellonella and Spodoptera littoralis. In addition, it enhanced host penetration 2.7-fold for S. carpocapsae and 1.5-fold for H. bacteriophora, and desiccation tolerance improved 1.2- and 1.7-fold, respectively. Heat tolerance and fecundity of the selected lines were somewhat reduced (MT50 by factors of 1.02 and 1.2 and fecundity by factors of 0.93 and 0.99, respectively) as compared to the foundation population. Improved HSA with substantial improvement of other traits may enhance field performance of these biocontrol agents.

A study of the improvement surface roughness and optimum machining characteristic of L-shaped tube STS 316L by electropolishing

Electropolishing (EP) is one of the most important processes for improving the corrosion resistance capability of a stainless steel (STS) 316L workpiece. This process removes nonmetallic inclusions and improves the mechanical and corrosion resistance of the stainless steel. The aim of this study was to investigate the influence of current and machining time on the effectiveness of electropolishing for an L-shaped tube. The workpiece was made of STS 316L stainless steel, and the cathode and anode were made of copper. The electrolyte was composed of sulfuric acid, phosphoric acid, and deionized (DI) water. To analyze the effectiveness of the electropolishing under various currents and machining times, the surface roughness of the workpiece was measured. The results showed that the EP process greatly decreased the surface roughness of the STS 316L stainless steel under all conditions tested.

Two new species of Haliotrema Johnston & Tiegs, 1922 (Monogenea: Dactylogyridae) from Acanthurus nigrofuscus (Forsskål) and A. triostegus (Linnaeus) (Teleostei: Acanthuridae) in the South China Sea.

Haliotrema nanhaiense n. sp. and Haliotrema triostegum n. sp. are described respectively from the gills of Acanthurus nigrofuscus (Forsskål) and Acanthurus triostegus (Linnaeus) in the South China Sea. Haliotrema nanhaiense n. sp. differs from other existing congeneric species by its male copulatory complex, comprising a C-shaped copulatory tube, a saucer-shaped base and a sickle-shaped accessory piece. Haliotrema triostegum n. sp. can be differentiated from all other members of Haliotrema by having a unique copulatory complex, a cup-shaped base, inverted L-shaped copulatory tube with a small sclerotised piece arising from its distal portion, and a large accessory piece from the proximal portion of copulatory tube.

Anesthesia machine breathing tube holder

Breathing tubes connect the anesthesia machine to the endotracheal tube and are composed of inspiratory and expiratory corrugated limbs. The two breathing tubes carry respiratory gases with volatile anesthetics to and from patients during general anesthesia. Although longer corrugated breathing tubes allow the anesthesia machine to be located farther from the patients, they are so long and flexible that they tend to hang down below the operating table and strain the endotracheal tube. When the breathing circuit system is interrupted due to disconnection of the elbow connector or Y-piece connector or due to a kinked tracheal tube, a dangerous ventilation failure may result. Breathing tube holders may help to avoid these accidents. Various commercially available breathing tube holders are used for this purpose increasingly commonly, but it is the authors' opinion that they have some drawbacks along with their advantages. Breathing tubes can easily become unattached from conventional breathing tube holders, because the grooves for the tubes are too shallow and opened too wide. We have devised a new design of breathing tube holder that improves practicality, stability and portability (Fig. 1). The L-shaped breathing tube holder, which can be made of either metal materials such as stainless- steel or aluminum or acryl, comprises two right-angled limbs (15 cm wide and 35 cm long for the long limb and 15 cm wide and 25 cm long for the short limb). One limb is used as a supporting plate inserted beneath the patient's pillow or operation table mattress, and the other holds the breathing tube. The large grooves on the top and sides of the device support and organize the corrugated breathing tubes, and numerous small clefts hold intravenous fluid lines or the gas sampling line. Fig. 1 A new design of breathing tube holder. The first advantage of the device is practicality. The lengths of the two limbs of the device are different so as to be applicable to both adults and pediatrics; the longer tube holding limb for adults can be switched to the supporting limb when used for pediatrics. Second, to achieve greater stability, the grooves on the top have narrow openings with widths similar to the outer diameter of the single breathing tube. The breathing tubes may be placed securely without being pulled out of the grooves after being inserted one after another. Also, the right angle of the lateral grooves improves stability. Finally, our device has the additional advantage of portability. This L-shaped device can be fully folded into one panel, which facilitates storage and transport. The breathing tube holder may be inapplicable when the device interferes with the operation field, although there are few contraindications for its use. There are some chances of disastrous ventilation failure due to unexpected interruption of respiratory circuits in mechanically ventilated patients. Our breathing tube holder mitigates the risk with its superior practicality, stability and portability. Its many advantages make it more reliable and much safer than traditional models.

Experimental Study on Seismic Behavior of Concrete-Filled L-Shaped Steel Tube Columns

Concrete-filled L-shaped steel tube columns can be used to save architectural space at room corners, and may have many advantages of structural behavior of common concrete-filled steel tubes as columns. In this paper, the seismic behavior of concrete-filled L-shaped steel tube columns (CFLSTs) was investigated. Six specimens subjected to a constant axial load and cyclically varying lateral loading were tested to study the effects of width to depth ratio of section, depth to thickness ratio of steel tube and axial load level on the strength, as well as stiffness, ductility and energy dissipation of CFLST columns. Experimental results showed that the displacement ductility of CFLST columns decreased significantly with the increase of axial load level, and the strength and stiffness degradations of CFLST columns were more significant with higher axial load level. With the increase of depth-thickness ratio of steel tube and depth-width ratio of section, the ductility and the lateral ultimate load-carrying capacity of CFLST columns also decreased gradually. All CFLST columns exhibited favorable energy dissipation and ductility, even for the columns subjected to high axial load, which indicates that this type of composite columns is adoptable in practical engineering, especially in seismic regions.

Plasma Bullets Propagation Inside of Agarose Tissue Model

This paper demonstrates plasma bullets generated by microsecond pulses in He flow propagation inside of conductive agarose gel tubes mimicking tissue. The objective of this paper is to understand the possibility of internal diseases' treatment (e.g., lung or intestinal cancer) using plasma jets. The propagation dynamics is studied using fast imaging technique, and production of reactive species is demonstrated both in gas phase (using optical emission spectroscopy) and inside of the agarose gel (using fluorescent dye). In addition, it is demonstrated that plasma bullets may propagate not only in a straight tubes, but also in L-shaped tubes, as well as be split in T-shaped tubes. All these facts offer an indication of possible successful application of plasma bullets for treatment of internal diseases, for example, lung cancers or intestinal diseases.

Study on Mechanism of L-Shaped Concrete-Filled Steel Tubular Columns Subjected to Axial Compression

In this paper, a constitutive relationship of the concrete core restrained by L-Shaped steel tube is put forward based on referring to the constitutive relations of core concrete in concrete-filled square steel tube columns, which takes the restraint of steel tube to concrete as an equivalent confinable effect coefficient . Load-deformation relationship of L-Shaped concrete-filled steel tubular column subjected to axial compression is analyzed by finite element analysis (using ABAQUS software). The predicted load versus deformation relationship cures are in good agreement with those of tests based on the finite element analysis, loads carried by steel tubes and concrete respectively during the loading process, as well as interactions between them are analyzed. Finally, influences of length-width ratio and width-thickness ratio on the interaction between steel tubes and concrete are investigated.

Theoretical and Experimental Studies of Hydraulic Characteristics of Discharge Tunnel with Vortex Drop

The velocities at given points in the volute chamber, the contracted section and the vertical dropshaft of a discharge tunnel with vortex drop were measured by a small specially designed L-shaped tube, as Laser Doppler Velocimetry (LDV) or Particle Image Velocimetry (PIV) would not work there due to the special structure of the discharge tunnel with vortex drop. Hydraulic empirical formulas were proposed to predict the velocities and the angles of the velocities made with the vertical direction θ. The theoretical analysis results were in good agreement with experimental data. Therefore, the method proposed in this paper can be used to analyze related characteristics of discharge tunnels with vortex drop. Additionally, different model scales were considered to predict the cavitation characteristics on the wall of a dropshaft in practical engineering.

Bacteriolytic activity and growth of marine isolates of labyrinthulids on dead bacterial cells

Thirteen strains of labyrinthulids were isolated from the coastal area of Kagoshima Bay, Kagoshima Prefecture, Japan and from Batan Bay, Panay Island, the Phillippines by using diatom double-layer agar plates. The cells of labyrinthulid isolates grew axenically on the dead bacterial cells and extract plus egg yolk agar medium (NSBEY agar). Three representative isolates were demonstrated to belong to the labyrinthulid phylogenetic group (LPG) based on 18S rDNA sequence analysis. As bacteriolytic activity of labyrinthulid isolates was examined, it was found that they could lyze only the dead cells of gram-negative bacteria and not those of gram-positive bacteria during incubation in both agar and liquid media. The optimum temperature range for bacteriolysis was 25–31°C. Orange carotenoid pigment was accumulated during the stationary growth phase of strain 00-Bat-05, Philippine isolate, cultured in an L-shaped tube containing a bacterial dead cell suspension. Concomitant rapid cell movement of developing zoospores was observed.

Ultra-simple adaptor to convert batch cells with mercury drop electrodes in voltammetric detectors for flow analysis

A simple, robust and fast-responding flow adaptor for mercury drop electrodes (MDEs) is described. An L-shaped PTFE tube with an internal diameter of 0.5 mm is fixed with a silicone ring on the glass capillary of a MDE, in such a way as to direct the outcoming flow onto the mercury drop, from a distance of about 0.5 mm. Any commercial or laboratory-made batch cell, provided with an MDE, serves for the purpose. The level of supporting electrolyte in the cell is maintained constant through a siphon or a lateral draining orifice. The adaptor is compatible with all the different brands and operating modes of the MDEs (free dropping, controlled drop time, renewable static drop, hanging drop or sessile drop). Flow injection experiments were conducted with the following amperometric detection modes: sampled-DC, reverse pulse amperometry (RPA), and anodic stripping voltammetry (ASV). The FIA-RPA peaks presented a R.S.D.<0.8% for 1.0×10 −5 mol l −1 lead(II) (N=30, V sample=100 μl). The response time (0–63% of the signal maximum) to a concentration step is 1.2 s for 500 μl injections of 0.1 mmol l −1 ascorbic acid in acetate buffer at a flow rate of 1 ml min −1, which corresponds to a response volume of 20 μl. As an example of practical application, copper(II) was determined in fertilizers by RPA using the standard addition method, at an analytical frequency of 90 injections per h.

Analysis Method of the Nonstationary Response of Acoustical-Structural Coupling Systems.

This paper presents the numerical analysis method of the nonstationary response of acoustical-structural coupling systems. The acoustical analysis is formulated by the Boundary Element Method based on the hyper-singular boundary integral equation in order to deal with very thin elastic structures in the open space. The structural analysis is formulated by the Finite Element Method using the triangular thin plate element. Those fundamental equations are coupled by using the force equilibrium and the flux continuity conditions in the Laplace transformed domain, and the time history of nonstationary responses are obtained by the numerical inverse Laplace transform. The validity of the proposed method is examined in comparison with an analytical result and besides by conducting the experiments of nonstationary excitation of thin plates installed in the rectangular acoustic tube which is excited by a sinusoidal sound pressure from the planewave-driving type speaker. Finally, a few numerical calculation examples are shown. Those analyses treat the flexible I-shaped and L-shaped acoustic tubes which are excited by the sinusoidal pressure generated at the one end of acoustic tubes, and air medium displacements and sound pressures traveling in the tube and transmitted to the out of tubes are visually shown.

Ventriculocoronary artery bypass results using a mesh-tipped device in a porcine model

Background. In this report we describe the in vivo evaluation of a device and ventriculocoronary artery bypass procedure that creates a permanent transmyocardial channel between the left ventricle and a coronary artery. Methods. The transmyocardial device, an L-shaped titanium tube with a meshed distal tip and an exterior polyester cuff, was implanted from the base of the left ventricle to the proximal left anterior descending coronary artery in 11 healthy juvenile domestic pigs using a beating-heart approach. Flow rates were measured at implant. Patency was assessed at explant for surviving animals at 2 (n = 3) and 4 weeks (n = 4). Results. Flow through the transmyocardial device after implantation was 74% of base line. Forward flow occurred during systole. Luminal patency was 100% at 2 weeks and 75% at 4 weeks. Histologic analysis showed little to no intimal proliferation at the coronary interface. Conclusions. This short-duration study shows promise for perfusing ischemic myocardium with systolic flow. The transmyocardial titanium conduit and treated coronary artery patency was good at 2 and 4 weeks and warrants further studies.

Development of an apparatus for cultivation of anaerobic microorganisms

A novel apparatus with an L-shaped test tube was developed for anaerobic cell cultivation. Anaerobic condition was achieved without the rigorous gassing with CO2 during the various stages of medium preparation. dispensation and cell inoculation. The growth of both moderate and strict anaerobes in this apparatus were similar to those obtained with the glove box method.

Reconstruction of the cervical trachea with a free forearm flap

With the aim of voice restoration after repair of a total defect or obstruction of the cervical trachea, we developed a new method of total cervical tracheal reconstruction with a free forearm flap. The forearm flap is inverted to form a tube and then interposed between the subglottic trachea and an adjacent cutaneous fistula created at the upper portion of the tracheostoma. A permanent tracheostoma is preserved, and an L-shaped silicone tube is inserted in the reconstructed cervical trachea and the tracheostoma as a stent. In two patients, both became able to speak.

Oxygen and "strictly anaerobic" intestinal bacteria. I. Effects of dissolved oxygen on growth.

The effects of oxygen on 29 strains of „strictly anaerobic„ bacteria, which are often found in human intestinal tracts, were studied. The initiation and rate of growth, together with the maximum extent of growth, in sealed L-shaped tubes containing a medium through which a gas mixture containing 5% O2 had been bubbled were compared with those under anaerobic conditions. On the basis of the results, these anaerobic bacteria could be divided into three general types: Type A; strains which grew in almost the same way as under anaerobic conditions, type B; strains which grew less well than under anaerobic conditions, and type C; strains incapable of growth initiation in the initial presence of the dissolved O2. After the experiments no residual O2 was found in the medium of type A strains. The decrease in O2 concentration was small, if any, in media of type B and C strains. Using representative examples of these three types, physical changes in the culture medium accompanying growth were observed in a stirred fermenter equipped with three electrodes; Eh, oxygen, and pH. The results were as follows: Type A: Growth of Veillonella alcalescens in the fermenter started after the complete comsumption of dissolved oxygen and when Eh had dropped below - 300 mV. A slight drop in pH occurred in parallel with the growth. Type B: In the culture of Bifidobacterium adolescentis, growth was simultaneous with the changes in O2 concentration, Eh, and pH. Type C: Growth of Bacteroides vulgatus was not initiated in the presence of the dissolved O2. Little change in O2 concentration, Eh or pH was observed. When bacterial cells which had grown in the medium initially containing dissolved O2 were subjected to serial transfer to similar fresh media, growth activity appeared to decrease progressively.

Determination of nitrogen-15 by combined system of sealed tube pyrolysis and mass spectrometer

A combined system of sealed tube combustion of nitrogen-containing sample and a simple mass spectrometer for detecting 14N-14N and 15N-14N has been established for the ultramicro sampling scale.A sample was placed in a heat-resistant glass tube having a capillary tip at one end as illustrated in Fig. 1, and highpurity oxygen from a stainless steel tube was passed through the glass tube for 8 min to purge the air, then the glass tube was sealed by a small hydrogen flame. The sealed tube was heated in a cylindrical electric furnace at 650°C for 90 min to ensure complete decomposition. The tube was introduced into the bottom of an inverted L-shaped tube as shwon in Fig. 2, while an iron piece was placed at the horizontal part. The inlet system was then evacuated and the iron piece was dropped onto the capillary end of the sealed tube to extract the combustion gas through the broken tip.A simple mass spectrometer, Yanaco Isotope Analyzer Model MSI-10, with the maximum M/e=200, the scan was between M/e = 28 and 29, where 14N-14N+, 14N-14N+ ions were determined. It has been found that an excessive signal response was obtained when the combustion time of the sealed tube was less than 50 min at the heating temperature of 650°C, probably because by incomplete combustion. The analytical results for approximately 10 μg of nitrogen with the proposed method was accurately coincided with those of the Rittenberg method using wet combustion, the latter being carried out by using at least 200 μg of nitrogen.

THE VERTEBRATE NOSE, REMARKS ON ITS STRUCTURAL AND FUNCTIONAL ADAPTATION AND EVOLUTION.

All adult tetrapods have in common that they can breathe while their mouth' is shut. Air is generally taken to lungs either via external nostril, nasal tube (vestibulum), nasal sac, choanal tube (nasopharyngeal duct), choana (internal noistril), mouth cavity, trachea and bronchi, or, shorter way, via latter three structures. When tracing origin of tetrapods and original function of air passage, it is therefore logical to look for fish having same type of communication between nose and mouth cavity, and to try to solve its evolution. Most attention has been paid to choana. Theories on origin of this internal opening of nose may be classified into five categories: (1) from a posterior excurrent nostril which has migrated down to edge of jaw and then, medially, into mouth cavity; (2) from an anterior incurrent nostril which has migrated same way; (3) by separation from an excurrent nostril at margin of jaw; (4) from posterior part of an adult naso-buccal groove; (5) from an accessory nasal sac developed from posterior end of an embryonic naso-buccal groove (paedomorphosis according to Panchen, 1967). These theories and their evidence have recently been reviewed by Panchen (1967). For various reasons, he and present author (Bertmar, 1966b) considered first three theories to be unacceptable. The fourth theory was recently presented by myself (Bertmar, 1966a). It was based on embryological evidence of lungfish and amphibians, but I remarked that no fossil evidence has yet been found to support it. However, Panchen was obviously inspired by this theory when he set up fifth theory a year later, but he was also influenced by works of Dahlgren, Atz, and Teichmann. Dahlgren (1908, 1927) and Atz (1952a, b) described teleost Astroscopus of family Uranoscopidae. Adults of this genus have both anterior and posterior external nostrils, as well as an internal opening of nasal sac which was considered by e.g., Szarski (1962) to be an independent new communication between nasal sac and mouth cavity. Atz also mentioned that nasal sac of related Uranoscopus has a blind, L-shaped tube, which almost reaches roof of mouth. As course of internal nasal passageway of Astroscopus is identical, and as roof of mouth cavity is pierced, Atz concluded that choanate condition thus formed should be derived from an accessory nasal sac. However, he also declared that the presence of internal nostrils in Astroscopus has little bearing on problem of origin of these structures in ancestors of tetrapods. The structures are, of course, not homologous. (Atz, 1952b: 375). However, neither in this nor in his other paper did he give any evidence of his opinion of nonhomology between internal nostril of Astroscopus and choana. Teichmann (1964) did not try to compare morphogenesis and position of tetrapodean choana and accessory nasal sacs in fish, and it is probably for this reason that he used quotation marks around words homologous and choana. As a matter of fact, neither Atz nor Teichmann have published any decisive opinion on structural evolution of choana. With regard to its functional evolution, however, Atz

II.—Aeolipiles as Fire-blowers

An aeolipile is a device whose essential feature is that vapour confined in it under pressure can issue from it only through a small aperture. Although the Oxford English Dictionary agrees with the French Academy in deriving ‘aeolipile’ from a combination of the name of the god of the winds, Aeolus, and the Latin pylae or the Greek Πύλαι, implying thus that originally it meant something like ‘doorway of Aeolus’ or ‘gates of the winds’, I am inclined to accept rather its derivation from ‘Aeolus’ and the Latin pila, a ball, and an original meaning ‘ball of Aeolus’ or ‘of the winds’. Vitruvius, writing during the reign of Augustus, says, in a passage concerned with the winds, ‘id autem verum esse ex aeolipilis aereis licet aspicere … fiunt enim aeolipilae aereae cavae. hae habent punctum angustissimum quo aquae infunduntur conlocanturque ad ignem, et antequam calescent non habent ullum spiritum, simul autem ut fervere coeperint, efficiunt ad ignem vehementem flatum’. This seems to show pretty clearly, by both the form of the word and the description of the object to which Vitruvius applies it, that the word was based on pila and not on pylae. Conceivably it was the spherical shape of early aeolipilic fire-blowers which suggested the trunnioned steam-filled ball provided with projecting L-shaped tubes from which the steam could issue and, by its reaction, cause the ball to revolve, which Hero of Alexandria describes in his Pneumatika, and which is still used to demonstrate to students a jet of steam's inherent reactive force. Hero's text does not, however, include any word relatable to the term Vitruvius applied to his fire-blowing spheres.

The Demonstration Ocular

Research Article| April 01 1946 The Demonstration Ocular Mary D. Rogick Mary D. Rogick Search for other works by this author on: This Site PubMed Google Scholar The American Biology Teacher (1946) 8 (7): 162–164. https://doi.org/10.2307/4437724 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation Mary D. Rogick; The Demonstration Ocular. The American Biology Teacher 1 April 1946; 8 (7): 162–164. doi: https://doi.org/10.2307/4437724 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentThe American Biology Teacher Search This content is only available via PDF. Article PDF first page preview Close Modal You do not currently have access to this content.