scholarly journals I. Experiments on the friction between water and air

1876 ◽  
Vol 24 (164-170) ◽  
pp. 441-442
Keyword(s):  
Water Column ◽  
Glass Tube ◽  
Soap Film ◽  
Feeding Tube ◽  
Vertical Position ◽  
Internal Diameter ◽  
Mutual Friction

The method adopted for estimating the mutual friction of water and air consisted in connecting a glass tube of 8 centims. in length and 0·72 internal diameter with the pipes which supply Vienna with water at a pressure of four atmospheres. Arrangements for securing a vertical position for the tube ensure a perfectly continuous jet, devoid of any broken surface; and a glass tube surrounding this jet, with its axis coinciding with that of the jet, acts as an aspirator into and along which air is drawn through a lateral feeding-tube. The amount of this indrawn air corresponding to the fall of a given amount of water was determined by observing the rate at which a film of soap was borne along the feeding-tube; and the velocity of the water causing the indraught was calculated from the diameter of the water column and the quantity of water discharged along it in a given time; but after having once determined the form of the slightly conical water column, the amount of water discharged was the only datum required for the calculation. The influence of a greater or less section of the air feeding-tube on the volume of the aspirated air was carefully determined, while also the absence of any appreciable retardation due to the soap film was established.

scholarly journals A Full Automatic Device for Sampling Small Solution Volumes in Photometric Titration Procedure Based on Multicommuted Flow System

2007 ◽  
Vol 2007 ◽  
pp. 1-6
Author(s):  
Sivanildo S. Borges ◽  
Gláucia P. Vieira ◽  
Boaventura F. Reis
Keyword(s):  
Flow System ◽  
Sodium Hydroxide Solution ◽  
Glass Tube ◽  
Automatic Device ◽  
Vertical Position ◽  
Good Precision ◽  
Small Solution ◽  
Relative Standard ◽  
Photometric Titration ◽  
Solution Volume

In this work, an automatic device to deliver titrant solution into a titration chamber with the ability to determine the dispensed volume of solution, with good precision independent of both elapsed time and flow rate, is proposed. A glass tube maintained at the vertical position was employed as a container for the titrant solution. Electronic devices were coupled to the glass tube in order to control its filling with titrant solution, as well as the stepwise solution delivering into the titration chamber. The detection of the titration end point was performed employing a photometer designed using a green LED (λ= 545 nm) and a phototransistor. The titration flow system comprised three-way solenoid valves, which were assembled to allow that the steps comprising the solution container loading and the titration run were carried out automatically. The device for the solution volume determination was designed employing an infrared LED (λ= 930 nm) and a photodiode. When solution volume delivered from proposed device was within the range of 5 to 105μl, a linear relationship (R = 0.999) between the delivered volumes and the generated potential difference was achieved. The usefulness of the proposed device was proved performing photometric titration of hydrochloric acid solution with a standardized sodium hydroxide solution and using phenolphthalein as an external indicator. The achieved results presented relative standard deviation of 1.5%.

scholarly journals IV. On the development of electric currents by magnetism and heat

1869 ◽  
Vol 17 ◽  
pp. 265-267
Keyword(s):  
Copper Wire ◽  
Glass Tube ◽  
Rubber Band ◽  
The Other ◽  
Internal Diameter ◽  
External Diameter ◽  
Thin Glass ◽  
Iron Wire ◽  
It Flexibility ◽  
Electric Current Passing

I have devised the following apparatus for demonstrating a relation of current electricity to magnetism and heat. A A, fig. 3, is a wooden base, upon which is supported, by four brass clamps, two, B, B, on each side, a coil of wire, C; the coil is 6 inches long, 1½ inch external diameter, and ⅜ of an inch internal diameter, lined with a thin glass tube; it consists of 18 layers, or about 3000 turns of insulated copper wire of 0·415 millim. diameter (or size No. 26 of ordinary wire-gauge); D is a permanent bar-magnet held in its place by the screws E, E, and having upon its poles two flat armatures of soft iron, F, F, placed edgewise. Within the axis of the coil is a straight wire of soft iron, G, one end of which is held fast by the pillar-screw H, and the other by the cylindrical binding-screw I; the latter screw has a hook, to which is attached a vulcanized india-rubber band, J, which is stretched and held secure by the hooked brass rod K and the pillar-screw L. The screw H is surmounted by a small mercury cup for making connexions with one pole of a voltaic battery, the other pole of the battery being secured to the pillar-screw M, which is also surmounted by a small mercury cup, and is connected with the cylindrical binding-screw I by a copper wire with a middle flattened portion O to impart to it flexibility. The two ends of the fine wire coil are soldered to two small binding-screws at the back; those screws are but partly shown in the sketch, and are for the purpose of connexion with a suitable galvanometer. The armatures F, F are grooved on their upper edges, and the iron wire lies in these grooves in contact with them; and to prevent the electric current passing through the magnet, a small piece of paper or other thin non-conductor is inserted between the magnet and one of the armatures. The battery employed consisted of six Grove’s elements (arranged in one series), with the immersed portion of platinum plates about 5 inches by 3 inches; it was sufficiently strong to heat an iron wire 1·03 millim. diameter and 20·5 centims. long to a low red heat.

scholarly journals IX. On the solar variations of magnetic declination at Bombay

1869 ◽  
Vol 159 ◽  
pp. 363-386
Keyword(s):  
Circular Hole ◽  
Focal Length ◽  
Flat Glass ◽  
Glass Tube ◽  
Vertical Position ◽  
Glass Vessel ◽  
Magnetic Declination ◽  
The Government ◽  
Intelligent Assistants

1. The observations discussed in the following pages were made at the Government Observatory at Bombay, during the years 1859 to 1865, and constitute a portion of a much larger series of observations of which the remaining part is still awaiting reduc­tion. With the exception of Sundays, and eight or ten complete days in each year, the observations were taken continuously at hourly intervals throughout the period of seven years. The observers were carefully trained Brahmins, who were under the im­mediate oversight of highly intelligent assistants of the same caste. 2. The instrument used was made by Grubb of Dublin, and consists of a rectangular bar-magnet suspended horizontally, and carrying a divided scale and a lens, by means of which its position can be determined from time to time by reading the scale with a fixed telescope properly placed. The dimensions of the magnet are 15 inches by 0.86 inch by 0.25 inch, and the broad surface is made to lie horizontal; the suspension-thread was formed of about forty fibres of untwisted silk, and is 35 inches long, being protected (but not concealed from view) by a glass tube 1.3 inch in diameter: the bot­tom of the glass tube rests upon the top of a cylindrical mahogany box (8.5 inches in height) which surrounds the magnet, and the top supports a horizontal divided circle (the torsion-circle), and a brass cross piece to which the suspension-thread is attached. The tube is secured in a vertical position by a mahogany cross bar which has a circular hole in its centre that fits over the upper end of the tube, and which is fixed at its ex­tremities to two copper pillars whose feet are screwed into the marble basement of the instrument; and the upper aperture of the tube with the attachments is screened from the outer air and dust by an inverted hemispherical glass vessel. A sliding-frame which carries above a finely divided scale etched upon glass is fixed by a binding-screw near the northern extremity of the magnet, and a similar frame carrying a lens, whose focal length is about 12.7 inches, is secured to the magnet at that distance to the southward of the glass scale, so that the latter is approximately in the principal focus of the lens. The vertical lines which form the scale are equidistant and generally of uniform length; but every fifth division is slightly and every tenth division considerably prolonged, and over the tenth divisions numbers are marked in consecutive order, thus allowing a nume­rical designation to be given with facility to every point of the scale when viewed by the telescope. To permit the scale to be viewed through its lens by a telescope outside the mahogany box, the latter has two small windows of flat glass suitably inserted in its curved side, and a lamp is placed on a stool to the northward of the masonry pillar which supports the declinometer, and is kept constantly burning. The joints and crevices, and for greater security, the whole outside surface of the cylindrical box was covered with paper to keep out small spiders or other insects.

Vertical Distribution of Northern Shrimp (Pandalus borealis) Larvae in the Gulf of St Lawrence; Implications for Trophic Interactions and Transport

1994 ◽  
Vol 51 (1) ◽  
pp. 123-132 ◽  
Author(s):  
Patrick Ouellet ◽  
Denis Lefaivre
Keyword(s):  
Vertical Distribution ◽  
Water Column ◽  
Suspended Particle ◽  
Stage I ◽  
Vertical Position ◽  
Pandalus Borealis ◽  
Northern Shrimp ◽  
Residual Transport ◽  
Larval Emergence ◽  
The Vertical Distribution

In the northwestern Gulf of St. Lawrence in spring 1987 and 1988, stage I and II northern shrimp (Pandalus borealis) larvae were concentrated in the upper (<30 m) layers above the permanent pycnocline and coincident with subsurface chlorophyll a and suspended particle concentration maxima; this was above other macrozooplankton taxa in the daytime. Shrimp larvae maintained their vertical position relative to the maximum density gradient in the water column in daytime but moved towards the surface at night. Estimation of larval residual transport (~66 km) during the first developmental stage (12 d) corresponded to the horizontal scale of patches of stage I shrimp larvae in the northwest sector of the Gulf. The result is consistent with the suggestion of localized and short-duration larval emergence in the sector. The direction of mass transport and current speed were similar throughout the upper layers of the water column; consequently, the direction and magnitude of larval shrimp transport were not dependent on their vertical position. We suggest that the vertical distribution maintained by shrimp larvae is a mechanism to ensure maximum food availability and to optimize development time in the stratified water of the northwestern Gulf of St. Lawrence.

Performance of the 20-minute whole blood clotting test in detecting venom induced consumption coagulopathy from Russell’s viper (Daboia russelii) bites

2017 ◽  
Vol 117 (03) ◽  
pp. 500-507 ◽  
Author(s):  
Indira Ratnayake ◽  
Fathima Shihana ◽  
Dhammika M. Dissanayake ◽  
Nicholas A. Buckley ◽  
Kalana Maduwage ◽  
...  
Keyword(s):  
Whole Blood ◽  
Blood Clotting ◽  
Glass Tube ◽  
Coagulation System ◽  
Internal Diameter ◽  
Consumption Coagulopathy ◽  
Snake Bites ◽  
Supplementary Material ◽  
Russell’S Viper ◽  
Research Assistants

SummaryThe 20-minute whole blood clotting test (WBCT20) is used as a bed-side diagnostic test for coagulopathic snake envenoming. We aimed to assess the performance of the WBCT20 in diagnosis of venom induced consumption coagulopathy (VICC) in Russell’s viper envenoming. Adult patients admitted with suspected snake bites were recruited from two hospitals. WBCT20 and prothrombin time (PT) test were performed on admission. WBCT20 was done by trained clinical research assistants using 1 ml whole blood in a 5 ml borosilicate glass tube with a 10 mm internal diameter. The PT was measured by a semi-automated coagulation system and international normalised ratio (INR) calculated. VICC was defined as present if the INR was >1.4. The diagnostic utility of WBCT20 was determined by calculating the sensitivity and specificity of the WBCT20 on admission for detecting VICC. There were 987 snake bites where both WBCT20 and PT were done on admission samples. This included 79 patients (8 %) with VICC. The WBCT20 was positive in 65/79 patients with VICC (sensitivity 82 %; 95 % confidence interval [CI]: 72–90 %) and was falsely positive in 13/908 with no coagulopathy. The WBCT20 was negative in 895/908 snake bites with no coagulopathy (specificity: 98 % 95 % CI: 97–99 %) and was falsely negative in 14/79 with VICC. Using trained clinical staff, the WBCT20 test had a relatively good sensitivity for the detection of VICC, but still missed almost one fifth of cases where antivenom was potentially indicated.Supplementary Material to this article is available online at www.thrombosis-online.com.

A Numerical and Physical Comparison of a Geometrically Simple Fixed and Floating Oscillating Water Column

2008 ◽  
Author(s):  
Rebecca K. Sykes ◽  
Anthony W. Lewis ◽  
Gareth Thomas
Keyword(s):  
Numerical Modelling ◽  
Water Column ◽  
Physical Modelling ◽  
Element Model ◽  
The Body ◽  
Internal Diameter ◽  
Oscillating Water Column ◽  
And Performance ◽  
Fixed Cylinder ◽  
Walled Cylinder

A truncated hollow vertical circular cylinder provides a useful conduit for analysing the behaviour and performance of an offshore Oscillating Water Column wave energy device. This paper presents the preliminary results from a numerical and physical modelling study of a fixed thin-walled and a floating thick-walled cylinder, together with the numerical modelling of a thick-walled fixed cylinder of the same internal diameter. Comparisons of the measured pressures internal to the column, and external to the body in the case of the floating model, are made with the predictions obtained using the numerical boundary-element model WAMIT. Body motions are also given for the floating model. The numerical modelling enables a comparison to be made between the diffraction pressure on a thin and thick walled cylinder of the same internal diameter.

scholarly journals The effect of temperature on the hissing of water when flowing through a constricted tube

1915 ◽  
Vol 91 (632) ◽  
pp. 481-485
Keyword(s):  
Glass Tube ◽  
Effect Of Temperature ◽  
Internal Diameter ◽  
General Description ◽  
Common Occurrence ◽  
Flexible Hose ◽  
The Subject ◽  
Pass Through ◽  
Constricted Tube ◽  
Moving Liquid

The tensile strength of liquids has been the subject of study under two (different conditions, the first of which may be called the statical condition, and was used by Berthelot and Worthington, and more recently by H. H. Dixon. In this method some liquid, at rest in regard to the walls of the containing vessel, is submitted to a stretching force. The second condition, in which the liquid is moving in relation to the walls of the vessel, and is at the same time submitted to a stretching force, has not been studied in detail. Osborne Reynolds has given a general description of the phenomenon, which is of common occurrence. When a liquid is flowing through a pipe of varying section, at the constriction the velocity may be so high that the corresponding diminished pressure in the liquid is sufficient to break it. This was the subject of his paper read before the British Association at Oxford, 1894. He regarded the effect as a boiling of the liquid under diminished pressure, just as boiling may be produced in warm water by removing the surface pressure. The experiments about to be described suggest that the phenomenon in the constricted tube is a true tensile rupture produced in the moving liquid. Osborne Reynolds describes his experiment thus: "Take a glass tube, say, ½ inch internal diameter and 6 inches long, and draw it down in the middle so as to form a restriction with easy gradual curves so that the inside diameter in the middle is something less than 1/10 inch, leaving the parallel ends of the tube something like 2½ inches each. And then connect one of these parallel ends by flexible hose to a water main which is controlled by a tap. Then, on first opening the tap, the water entering from the main will fill the tube as far as the restriction, and pass through the restriction, but it will not, in the first instance, of necessity fill the tube on the far side of the restriction. If the water is turned on very slowly and the open end of the tube is inclined upwards, then the water will accumulate and fill the tube, displacing the air. But if the water is turned on sharply so that when it reaches the neck it has a velocity of 40 or 50 feet a second, the water after passing the minimum section will preserve its velocity and shoot out. as a jet from u squirt, not touching the sides of the glass, while if the open end of the tube be held downwards the water, whatever the velocity, will, after passing the restriction, run out of the tube without filling it.

scholarly journals Description of a mountain barometer, the column of which is divisible into two portions for safer and more convenient transport

1837 ◽  
Vol 3 ◽  
pp. 39-40
Keyword(s):  
Glass Tube ◽  
Hardened Steel ◽  
Internal Diameter ◽  
Total Height ◽  
Intermediate Space ◽  
Perfect Security ◽  
Internal Screw

The object of the contrivance described in this paper is to reduce the length of the barometer, when not in use, to one-half the usual length; and to render the position in which it may be carried indifferent. It consists of a glass tube eighteen inches long, cemented into a steel cistern two inches long, and one inch internal diameter, which is furnished with an internal screw, for receiving a hardened steel screw and hemisphere cemented to the end of a syphon tube. The long leg of this tube has an internal diameter of only the six or eight hundredths of an inch, and it is further contracted at the end to the twenty-fifth of an inch, so that no air can pass when the mercury is descending through it. The shorter leg of the syphon has the same bore as the tube. When the two parts are screwed together, and the whole inverted, the mercury descends from the cistern, fills the long leg of the syphon, and ascends to a certain height in the shorter leg. Any air that may have existed in that part of the cistern which was not occupied by the mercury, is collected in an intermediate space, external to the column of mercury, and therefore can have no influence on the total height of that column, which is determined solely by the pressure of the external atmosphere. On gently reversing the position of the barometer, the mercury will repass from the syphon into the cistern, where it is confined by a stopper, as in a bottle: and may then be carried about in any position in perfect security.

II. Experiments to ascertain the cause of stratification electrical discharges in vacuo

1875 ◽  
Vol 23 (156-163) ◽  
pp. 356-361 ◽  
Keyword(s):  
Thin Sheet ◽  
Glass Tube ◽  
Silver Wire ◽  
The Other ◽  
Detailed Account ◽  
Common Salt ◽  
Internal Diameter ◽  
Electrical Discharges ◽  
Vulcanized Rubber ◽  
Gutta Percha

Some results obtained in working with a chloride-of-silver battery 1080 cells in connexion with vacuum-tubes appear to be of sufficient interest to induce us to communicate them to the Society, in anticipating of the more detailed account of an investigation which is now being prosecuted, and which it is intended to continue, shortly, with a battery 5000 cells, and possibly with a far greater number. The battery used up till now consists of 1080 cells, each being formed a glass tube 6 inches (15·23 centims.) long and ¾ of an inch (1·9 centims) internal diameter; these are closed with a vulcanized rubber stopp (cork), perforated eccentrically to permit the insertion of a zinc rod, carefully amalgamated, 3/16 (0·48 centim.) of an inch in diameter and 4·5 inch (11·43 centims.) long. The other element consists of a flattened silver wire passing by the side of the cork to the bottom of the tube a covered, at the upper part above the chloride of silver and until it pass the stopper, with thin sheet gutta percha for insulation, and to protect from the action of the sulphur in the vulcanized corks; these wires a 1/16 of an inch (0·16 centim.) broad and 8 inches (20·32 centims.) long. the bottom of the tube is placed 225·25 grains (14·59 grms.) chloride silver in powder; this constitutes the electrolyte: above the chloride silver is poured a solution of common salt containing 25 grammes chloride of sodium to 1 litre (1752 grains to 1 gallon) of water, to with about 1 inch (2·54 centims.) of the cork.

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