Arrangement Of Apparatus Research Articles

An Experimental Study of Parasitic Wire Reflectors on 2.5 Meters

This paper presents the results of an experimental investigation of the energy distribution in a horizontal plane due to the juxtaposition of a vertical antenna and parallel parasitic rod-shaped conductors. The reduction of spurious radiation to a minimum, through a special arrangement of the apparatus, results in symmetry of the polar radiation patterns and makes it possible to appraise accurately the dependency of the forward radiation, directivity, and backward radiation on the dimensions of the reflector system. Typical polar distributions of single, double, trigonal, trapezoidal, plane, and parabolic arrays are shown. The distance between antenna and reflector for optimum forward effect, for plane and other multiple-wire arrays, was found to depend, in general, on the number, length, and spacing of the reflector elements. The parabolic reflector is considered in greater detail and, while most of the results are seen to be in qualitative agreement with experiments reported abroad, it is evident that the aperture of a grid reflector is not always a consistent "figure of merit" of its performance. The results of the parabolic arrays are used, finally, to discuss a theoretical formula derived by Ollendorff.

Micro-Manipulation of Cells in Mammals

An arrangement of apparatus for applying micro-manipulative procedures to cells in living mammals is described. It was found satisfactory for manipulation of pericapillary cells and capillary endothelium in the greater omentum of the cat.An animal board, a Bausch and Lomb triple purpose micro-projector and a double Fitz micro-manipulator were mounted on a spring platform. The micro-needles were drawn from Pyrex rods by hand. The stage of the microscope was modified to protect the condenser from fluids. Warm saline solution was carried to the exposed omentum thru flexible rubber tubing.The use of a micro-dissection chamber which immobilized the part of the omentum under manipulation is explained. The construction of this chamber is shown by diagrams. A camera support was bolted to the base of the micro-manipulator.The arrangement of apparatus is shown by a photograph.

Power supply for the Pennsylvania railroad

An energy consumption of 238,000,000 kwhr per year will be required to handle through passenger trains on the electrified portion of the Pennsylvania Railroad system between New York City and Philadelphia, Pa., on which through service recently was initiated. This article describes the system used to supply that energy to the moving trains. The arrangement of apparatus and circuits adopted has resulted in low first cost, low operating maintenance, and reliability and simplicity of operation.

A New Determination of the Disintegration Constant of Uranium by the Method of Countingα-Particles

Alpha-particles emitted by a known amount of pure ${\mathrm{U}}_{3}$${\mathrm{O}}_{8}$ in the form of thin films were restricted in their passage into an ionization vessel by cylindrical channels of a grid placed over the material. The method of counting $\ensuremath{\alpha}$-particles alone was that of Greinacher. All $\ensuremath{\alpha}$-particles entering the ionization chamber automatically registered on a mechanical counter, for which an elaborate electrical and mechanical arrangement of apparatus was used. Over 100,000 counts were made from two specimens differing in surface density in the ratio of nearly 5 to 1. The ${\ensuremath{\lambda}}_{\mathrm{UI}}$ obtained is ${1.53}_{2}$${(10)}^{\ensuremath{-}10}$ ${\mathrm{yr}}^{\ensuremath{-}1}$ or $T={4.52}_{4}{(10)}^{9}$ yr, a value consistent with Gleditsch's ${\ensuremath{\lambda}}_{\mathrm{Ra}}=4.11{(10)}^{\ensuremath{-}4}$ ${\mathrm{yr}}^{\ensuremath{-}1}$, Boltwood's radium to uranium ratio of 7.40${(10)}^{\ensuremath{-}7}$ and branching ratio between 0.96 and 0.97.

Ultrasonic Radiation and Yeast Cells

A system capable of producing a series of high frequency waves in fluid may be constructed by placing a piezoelectric crystal of carefully prepared quartz in a di-electric liquid such as xylol. A pair of electrodes is then placed upon opposite sides of the quartz crystal and should be connected with a high frequency oscillator. Such an arrangement of apparatus allows one to set up compression waves even of radio frequency in the liquid. A system similar to this has been described by Wood and Loomis.1 Radiation by the resultant ultrasonic vibration has been shown by Wood and Loomis1 to be destructive to certain varieties of organisms including algae, but it was their opinion that bacteria are not injured by such treatment. Radiation by ultrasonic vibration may be attended by cavitation of included gases and it is considered probable by Johnson2 and by Schmitt and Uhlemeyer3 that this mechanical expulsion of the gases is the cause of disruption of living cells. Recent observations of Wu and Liu4 indicate th...

Function of the Columnar Epithelium of the Ciliary Body of Albino Rabbits.

The assumption of secretory function of the non-pigmented epithelium of the ciliary body (Leber,1 Seidel2) has not been satisfactorily confirmed. Some clinical experience of quick absorption of vitreous hemorrhages, however, seems to point to a possible absorbing function; and Meller3 was able to show blood pigments in the inner layer of ciliary epithelium in such a case. Experiments were therefore attempted on albino rabbits to investigate this question.The ciliary body of the rabbit is covered by an inner and an outer layer of epithelium. The inner epithelial cells are not uniform, some being columnar, others cubic or flat, while those of the outer layer are uniformly cubic. Each of the columnar cells, which are concerned in this study, is limited sidewise by a very thin membrane and outwardly by a definite thick membrane closely similar to the cuticular membrane of the intestinal columnar cells. Further, the intracellular arrangement of mitochondria and Golgi apparatus is identical to that of the intes...

The electrical condition of hot surfaces during the adsorption of gases. Part I.-Gold and silver surfaces at temperatures up to 850°C

In 1914, Dr. H. Hartley published an account of an investigation upon the electrical condition of a gold surface heated in contact with various gases, in the course of which he found, inter alia , that gold acquired a negative charge when in contact with hydrogen or carbonic oxide, or a mixture of either of these gases with oxygen, and a positive charge when in contact with oxygen alone. In view of the fact that these interesting and significant results indicate a possible clue to the mechanism and nature of the heterogeneous catalysis of gaseous reactions by hot surfaces, the present investigation was undertaken with the object of confirming and extending Dr. Hartley’s work. The main difficulty encountered in the course of this investigation lay in the avoiding of spurious electrical effects. We believe, however, that the design and arrangement of apparatus finally adopted by us were such as to preclude the occurrence of such effects. It was also found necessary to employ a pumping system which would permit of the rapid attainment of a high degree of vacuum, and to prevent ingress of any traces of mercury vapour into the vessel containing the metal surface, which would otherwise have been contaminated with mercury.

The Fabry and Perot parallel plate talon

A concise account is given of the theory and use of the instrument, together with descriptions of the customary arrangements of apparatus and the methods of etalon adjustment. An approximate expression for resolving power is deduced; values obtained with it are tabulated and shown. Details are given of a photographic method of finding the reflecting power of the metallic films of the etalon. If it is desired to use the instrument in the infra-red or ultra-violet, combinations other than silver films on glass must be used. A list of such combinations is given, with the region for which each is best suited. Finally, as an aid to comparison, some of the most important properties of the etalon, Lummer plate, and echelon are gathered together and tabulated.

A DEPARTMENT OF PHYSICAL THERAPY

Beekman Street Hospital was reorganized in the spring of 1924. When the new staff decided to devote more attention to the care of industrial patients, it was believed necessary that they should receive physical therapy. I was asked to organize and take charge of the new department. The original space allotted for the department was about 1,100 square feet, and this was sufficient for about nine months, when plans had to be made to enlarge it. At present even the new department of 1,900 square feet is proving to be too small. When space is considered in planning a department of physical therapy, it always would be wise to make the minimum 2,000 square feet, even in a small hospital of 100 beds. It is particularly difficult to expand a department, as the wiring and arrangement of apparatus should be planned originally to last for a long time. The apparatus

The Fabry and Perot parallel plate talon

A concise account is given of the theory and use of the instrument, together with descriptions of the customary arrangements of apparatus and the methods of étalon adjustment. An approximate expression for resolving power is deduced; values obtained with it are tabulated and shown. Details are given of a photographic method of finding the reflecting power of the metallic films of the étalon. If it is desired to use the instrument in the infra-red or ultra-violet, combinations other than silver films on glass must be used. A list of such combinations is given, with the region for which each is best suited. Finally, as an aid to comparison, some of the most important properties of the étalon, Lummer plate, and echelon are gathered together and tabulated.

A SIMPLE METHOD OF ELIMINATING DANGER OF EXPLOSION DUE TO STATIC SPARK IN GAS-OXYGEN APPARATUS

Ethylene has been used at the Battle Creek Sanitarium for nearly all the major and minor surgery since February, 1924, and has proved a most satisfactory anesthetic. We have had no accidents thus far, although the new anesthetic has been used under conditions similar to those in other hospitals until the present apparatus was devised. Luckhardt, 1 Brown, 2 and Davis 3 have in recent articles given conditions under which ethylene might explode, but have not made definite suggestions or recommendations as to the arrangement of the anesthesia apparatus to avoid these accidents. As far as we know, up to the present time the manufacturers of anesthesia apparatus have not equipped their machines with any device that will eliminate the possibility of explosions. We have made various tests by means of a static machine and the electroscope, and have demonstrated that a simple arrangement that grounds every part of the

THE VISIBILITY OF MONOCHROMATIC RADIATION AND THE ABSORPTION SPECTRUM OF VISUAL PURPLE

1. After a consideration of the existing data and of the sources of error involved, an arrangement of apparatus, free from these errors, is described for measuring the relative energy necessary in different portions of the spectrum in order to produce a colorless sensation in the eye. 2. Following certain reasoning, it is shown that the reciprocal of this relative energy at any wave-length is proportional to the absorption coefficient of a sensitive substance in the eye. The absorption spectrum of this substance is then mapped out. 3. The curve representing the visibility of the spectrum at very low intensities has exactly the same shape as that for the visibility at high intensities involving color vision. The only difference between them is their position in the spectrum, that at high intensities being 48 micromicro farther toward the red. 4. The possibility is considered that the sensitive substances responsible for the two visibility curves are identical, and reasons are developed for the failure to demonstrate optically the presence of a colored substance in the cones. The shift of the high intensity visibility curve toward the red is explained in terms of Kundt's rule for the progressive shift of the absorption maximum of a substance in solvents of increasing refractive index and density. 5. Assuming Kundt's rule, it is deduced that the absorption spectrum of visual purple as measured directly in water solution should not coincide with its position in the rods, because of the greater density and refractive index of the rods. It is then shown that, measured by the position of the visibility curve at low intensities, this shift toward the red actually occurs, and is about 7 or 8 micromicro in extent. Examination of the older data consistently confirms this difference of position between the curves representing visibility at low intensities and those representing the absorption spectrum of visual purple in water solution. 6. It is therefore held as a possible hypothesis, capable of direct, experimental verification, that the same substance-visual purple-whose absorption maximum in water solution is at 503 micromicro, is dissolved in the rods where its absorption maximum is at 511 micromicro, and in the cones where its maximum is at 554 micromicro (or at 540 micromicro, if macular absorption is taken into account, as indeed it must be).

Milwaukee Experience with Compound Meters

Milwaukee's experience with compound meters dates from May, 1912, when the Meter Department installed, for service test, a 4-inch compound meter of a reliable make, on the service of the meter repair shop. This service is used solely for the testing apparatus and one hydraulic sidewalk lift. The stream flows on this line are from 3 inches to y^-inch. On April 1, 1920, with a total registration of 3,455,022 cubic feet on the dial of the current section of the meter, and 689,652 cubic feet on the dial of the disc section, this meter was subjected to a weight test and the following results were obtained. On the 2-inch stream size (the largest permissible with present arrangement of testing apparatus) the current section meter showed an accuracy of 100.1 per cent and on the f -inch stream 96.6 per cent, while on the disc section operation the percentage of accuracy on the J-inch stream was 100.8, on the f-inch stream 99.2, on the r^-inch stream 99.2, and on the y^-inch stream 84.4. In this meter there is a point of alternation or change over of stream flow through the current and disc section at about the f -inch stream. That is, at this point the valve is in a state of suspension or leakage and permits the diversion of a stream through each section too small for accurate registration on either. This condition, however, is not of very great concern, as it is not very probable that in actual service use the valve would remain in this suspended position for any period, due to the fluctuation of pressure and variation in consumption. With a view to determining the relative accuracy of the compound type and the disc type of meters, a test was conducted for a period of one week by installing a 3-inch bronze case meter on the line in conjunction with the 4-inch compound, the compound meter being a sub-meter to the disc meter. The disc meter is one which

The measurement of transmission-factor

An investigation has been made of various arrangements of apparatus designed for the determination of transmission-factor by the measurement of a single quantity. An integrating method has been studied, and under certain conditions appears to be satisfactory. The results appear satisfactory for practical purposes. The transmission-factors have been obtained for several representative slightly diffusive glasses for two kinds of illumination; namely, (1) a narrow beam of light directed perpendicularly to the surface of the specimen, and (2) uniformly diffused light reaching the specimen from all directions above its plane. The latter may be known as hemispherical illumination. Some of these specimens may be described as coarsely refractive. In general the transmission-factor is less for diffused (hemispherical) illumination than for a narrow beam of light directed perpendicularly. It has been shown that the transmission-factor of such glasses as studied in this investigation depends upon the position of the glass with respect to the light-source for a narrow beam of light directed perpendicularly to the specimen. In other words, the transmission-factors are generally considerably greater when the rought surface faces the light-source than when the smooth side is toward it. This difference is very apparent visually in the case of ribbed glasses, but it has been found to exist even for so-called “frosted” or etched glasses. Several simple photographic procedures have been carried out with the aim of representing certain characteristics of such glasses for which verbal description is unsatisfactory. These include the surface character, the cross-section, the appearance, and the scattering of light after passing through a specimen.

PRESENT STATUS OF THE MINERAL WATER INDUSTRY

PRESENT STATUS OF THE MINERAL WATER INDUSTRY Affiliation Frank L. Rector CopyRight https://doi.org/10.2105/AJPH.7.10.868 Published Online: August 30, 2011

Indoor and Outdoor Substations in Pennsylvania

This paper covers some points in substation design for installations for the lower voltages, including choice of location, type of building and arrangement of electrical apparatus. The subject is treated in three divisions, namely: customers' substations fed from the distribution system, customers' substations fed from the transmission system and company's substations. Attention is called to some of the advantages of both the outdoor and indoor substations for each of the different divisions. Points to be considered in the selection of locations for substations are outlined and several types of buildings, particularly the one of concrete slab construction, are described. Attention is also called to different arrangements of electrical equipments, which may be employed for installations of various sizes. Different schemes for installing high-tension switchboard apparatus are considered, attention being called to the open wire and the cell structure installations, with special reference to the concrete cell structure and the method employed in its construction.

The Measurement of Energy Losses in Condensers Traverse, by High-Frequency Electric Oscillations

In this Paper an arrangement of apparatus is described for the purpose of measuring the internal energy losses in condensers traversed by high frequency (H.F.) currents. It is shown that these energy losses in condensers may be considered as if they were due to a resistance loss in a hypothetical resistance in series with the condenser, the condenser itself being supposed to have a perfect non-dissipative dielectric of the same dielectric constant. This hypothetical resistance is not constant, but is a function of the condenser current. The experiments were conducted by the use of a special form of impact dischargers comprising two flat plates immersed in oil, one stationary and the other revolving at a high speed. This discharger was placed in series with a primary circuit and condenser, and H.F. oscillations were set up in the primary having any desired frequency. A secondary circuit loosely coupled consisted of a wire whose H.F. resistance could be determined, the condenser to be examined and a hot-wire ammeter and variable resistances. The measurements consisted in observing the reading of the ammeter, and then changing the current created in the secondary circuit by a small amount by adding a known resistance which altered the decrement of the circuit, but not its inductance. From these readings an equation is obtained for the hypothetical condenser resistance. It is shown that the product of the square of the secondary current A2 and the total resistance R of the secondary circuit is constant, and hence that the unknown condenser resistance ρ can be found from observations of the change in A2 when an additional resistance r1 is interpolated in the condenser circuit. The energy loss in the condenser is then A2ρ watts. Condensers with various dielectrics, air, oil, glass and ebonite, were examined, and the dielectric energy losses D are stated in micro watts per cubic centimetre of dielectric for given values of the electric force E. It is shown thus D can be expressed as a function of E in the form D=XEY, where X is a constant depending on the current density, and Y is a constant depending on the nature of the dielectric. For oil and air these power losses are relatively small, but for glass and ebonite large. The necessity for measuring these losses in the case of radiotelegraphic condensers is emphasised.

Power plant economics

Three years ago the steam-power plant for the generation of electricity had apparently settled down to an almost uniform arrangement of standard apparatus in which one power plant differed from another only in details of construction of engines, generators, and auxiliaries. As only about twenty years had then elapsed since the first central station Was put in operation on a commercial basis, this uniformity of design seemed to indicate that in the near future it would only be necessary to purchase a standard set of power-plant drawings, and make the necessary changes in size of units in order to have a station of the best type known to the art.

Safety Devices in Central Stations and Sub-Stations

A review of general principles followed in the design and arrangement of electrical apparatus of generating stations, transmission lines and sub-stations and a list of safeguards against breakdowns and devices for localizing and clearing faulty elements of the system. Advantages of storage and reserve supply to ensure continuity of service to customers.

Societies and Academies

PARIS. Academy of Sciences, August 13.—M. Maurice Lévy in the chair.— On the neogenic regions of Lower Egypt and the Isthmus of Suez, by MM. C. Depéret and R. Fourtau. Of the Miocene formation the following were recognised:—The Burdigalian, or first Mediterranean stratum, by the presence of Echinolampas amplus, Scutella Innesi, Lovenia, Cidaris avenionensis, Amphiope truncata and other fossils; the Vindobonian, or second Mediterranean stratum, by a blue lime containing Pecten cristato-costatus and numerous echinoderms. Of the Pliocene, in the neighbourhood of Cairo, are layers of yellowish sand containing Clypeaster aegyptiacus and other characteristic fossils.—The area of the basins of Russia in Asia, by M. J. de Schokalsky. The map is made upon the scale of I in 4,200,000, and the area evaluated by means of a sheet of celluloid divided in square millimetres. The area found is 16,085,000 sq. kilometres.—On a hypsometric map of European Russia, by M. J. de Schokalsky. The previous map of M. de Tillo was limited by the latitude 60° N.; the present map includes the whole of European Russia upon a scale of I in 15,300,000.—Observations of the Borelly comet, made at the Observatory of Algiers with the 31.8 cm. equatorial, by M. F. Sy.—A new arrangement of apparatus serving to measure geodesic bases, by M. Alphonse Berget. Ruled plates of iron floating in a bath of mercury are used instead of the ordinary scales. The method has the advantage of securing without trouble the absolute horizontally of the rules; two consecutive rules are necessarily in the same horizontal plane, since their mercury baths are connected; there is no correction necessary for the flexure of the rules, and the temperature correction is much more certain.—Stereoscopic vision of curves traced by a phase apparatus, by M. Marc Dechevrens.—Properties of magnetic deposits obtained in a magnetic field, by M. Ch. Maurain. Iron was deposited in a magnetic field either from a solution of ferrous and ammonium chlorides, or from a solution of ferrous sulphate in sodium pyrophosphate. It was found that the intensity of magnetisation of different layers of the deposit growing in a uniform field has the same value, and that the uniform magnetisation acquired by a deposited strip increases with the strength of field in which the deposit is obtained.—The rôle of discontinuities in the propagation of explosive phenomena, by M. Paul Vieille. On the assumption of an adiabatic elasticity, together with continuity, the velocities of wave propagation found in certain cases are too great. It is necessary to assume that the phenomenon is discontinuous.—Action of hydrogen upon the sulphides of arsenic, by M. H. Pélabon. Details of experiments of the interaction of realgar and hydrogen in sealed tubes at 610° C. The reaction is a reversible one, and the limit is affected by the introduction of an excess of arsenic.—The properties of the blue oxide of molybdenum, by M. Marcel Guichard. The blue oxide is a molybdate, and could not be obtained free from water, two oxides of molybdenum only existing in the anhydrous state, MoO2 and MoO3.—On the colouring matter of Echinus esculentus, by M. Griffiths.—On the composition of the ashes of some medicinal plants, by M. Griffiths.—On a cause of error in the examination of wines for salicylic acid, by M. J. Ferreira da Silva. The method of Petlet and Grobert will indicate the presence of salicylic acid in a pure wine that is really free from it. The official German method gives exact results.— On a variety of the anthrax bacillus; a short asporogenic form, Bacillus anthracis brevigemmans, by M. C. Phisalix. In the organism of the dog the B. anthracis undergoes important modifications, becoming shorter with a rapid and complete segmentation. It is still uncertain whether this should be regarded as a variety or a new species.—Anti-hepatic serum, by M. C. Delezenne.—Application to man of the regeneration of confined air by means of sodium peroxide, by MM. A. Desgrez and V. Balthazard. The apparatus described weighs twelve kilograms, and by its means a man can penetrate easily into an irrespirable atmosphere.