Nomenclature for glass bulb designation system for lamps

2015 ◽  
Keyword(s):  
Glass Bulb

scholarly journals XXI. On the construction of a new calorimeter for determining the radiating powers of surfaces in air; and its application to the surfaces of various mineral substances

1860 ◽  
Vol 150 ◽  
pp. 379-408
Keyword(s):  
Surrounding Medium ◽  
The Other ◽  
Absolute Amount ◽  
Present Communication ◽  
Atmospheric Air ◽  
Glass Bulb ◽  
Heated Body ◽  
Series Of Experiments ◽  
Quantity Of Heat ◽  
Limited Induction

When my paper on the Conductivity of various Substances was presented to the Society, it was intimated to me on the part of the Council of the Society, that it might be advisable to determine absolute instead of relative conductivities, the latter being alone attempted in my previous experiments. It has been partly in consequence of this intimation, as well as from the desire to make my investigations the more complete, that I have given my attention to the construction of a calorimeter which might serve for this purpose. The present communication contains a description of this instrument, with the results which it has enabled me to obtain respecting the absolute quantities of heat which emanate from the surfaces of certain substances under given conditions. 1. When a body is placed in atmospheric air (or any gas), the quantity of heat which is lost from its surface in a given time, when its temperature is higher than that of the surrounding medium, will be greater than if it were placed in a vacuum, other conditions remaining unaltered. In the latter case the heat escapes by simple radiation; in the other case a portion of the heat also escapes in consequence of the contact of the air with the surface of the heated body. Dulong and Petit ascertained by a careful series of experiments, the laws according to which the mercury contained in the bulb of a thermometer cools, or those which govern the quantity of heat which escapes from the surface of the containing bulb, when placed in a vacuum, in air, or in several kinds of gases. These experiments were made with the glass bulb naked, and also when it was silvered, so that the laws of radiation which they established were strictly in reference only to surfaces of glass and those of silver. Certain laws were identical in both these cases, and hence it was concluded, though by a limited induction, that the same laws were applicable to all other surfaces. They did not, however, give the absolute quantity of heat which, under given circumstances, and in a given time, emanates from the surfaces of the glass or silver with which they experimented. The instrument which I have constructed gives very easily this absolute amount of heat, as I believe, with very approximate accuracy.

Electrodeless breakdown in elliptically polarized fields at 60 Hz

1983 ◽  
Vol 61 (9) ◽  
pp. 1284-1290
Author(s):  
D. E. Friedmann ◽  
F. L. Curzon ◽  
M. Feeley
Keyword(s):  
Field Strength ◽  
Linear Polarization ◽  
Breakdown Strength ◽  
Breakdown Threshold ◽  
Glass Bulb ◽  
Maximum Field Strength ◽  
High Fields ◽  
Strength Formula ◽  
Elliptically Polarized ◽  
Maximum Field

Theoretical and experimental results are presented on the frequency of electrodeless breakdown (fB) of a gas in a spherical glass bulb immersed in an elliptically polarized field of maximum field strength [Formula: see text] and frequency fA (~60 Hz). It is found that the breakdown threshold is independent of the ellipticity and that graphs fB versus [Formula: see text] are stepped at low fields and linear at high ones. At high fields, fB = fAl/e0 where l is the circumference of the phasor and e0 is the breakdown strength of the gas ([Formula: see text] and [Formula: see text] respectively for circular and linear polarization). The implications of the results for measuring environmental fields are given.

scholarly journals I. On the absolute expansion of mercury

1912 ◽  
Vol 211 (471-483) ◽  
pp. 1-32 ◽  
Keyword(s):  
Hydrostatic Method ◽  
Physical Problems ◽  
Glass Bulb ◽  
Different Temperatures ◽  
The Mean ◽  
The Absolute ◽  
Made In

The determination of the expansion of mercury by the absolute or hydrostatic method of balancing two vertical columns maintained at different temperatures does not appear to have been seriously attempted since the time of Regnault (‘Mém. de l’Acad. Roy. des Sci. de l’Institut de France,' tome I., Paris, 1847). His results, though doubtless as perfect as the methods and apparatus available in his time would permit, left a much greater margin of uncertainty than is admissible at the present time in many cases to which they have been applied. The order of uncertainty may be illustrated by comparing the value of the fundamental coefficient of expansion (the mean coefficient between 0° and 100°C.) given by Regnault himself, with the values since deduced from his observations by Wüllner and by Broch. They are as follows:— Regnault . . . . . . 0·00018153. Wüllner . . . . . . 0·00018253. Broch . . . . . . . 0·00018216. The discrepancy amounts to 1 in 180 even at this temperature, and would be equivalent to an uncertainty of about 4 per cent, in the expansion of a glass bulb determined with mercury by the weight thermometer method. The uncertainty of the mean coefficient is naturally greater at higher temperatures. If, in place of the mean coefficient, we take the actual coefficient at any temperature, the various reductions of Regnault’s work are still more discordant, and the rate of variation of the coefficient with temperature, which is nearly as important as the value of the mean coefficient itself in certain physical problems, becomes so uncertain that the discrepancies often exceed the value of the correction sought. It is only fair to Regnault to say that these discrepancies arise to some extent from the various assumptions made in reducing his results, and are not altogether inherent in the observations themselves.

Anomalous hypoxic acidification of medullary ventral surface

1991 ◽  
Vol 71 (6) ◽  
pp. 2211-2217 ◽  
Author(s):  
F. D. Xu ◽  
M. J. Spellman ◽  
M. Sato ◽  
J. E. Baumgartner ◽  
S. F. Ciricillo ◽  
...  
Keyword(s):  
Ventral Surface ◽  
High Pco2 ◽  
Nerve Roots ◽  
Arterial Pco2 ◽  
Glass Bulb ◽  
Response Slope ◽  
Left Posterior ◽  
End Tidal ◽  
Arterial O2 Saturation ◽  
Ph Electrodes

In castrated male goats, two flexible catheters, one open ended for reference and the other ending in a 1-mm-diam glass bulb pH electrode, were advanced ventrally through a left posterior fossa craniotomy into the subarachnoid space between the 9th and 10th cranial nerve roots, passing medially into cerebrospinal fluid (CSF) over the medullary ventral surface (MVS). They were anchored to dura and fascia, tunneled under the scalp, and terminated in connectors on the left horn. After several days for recovery, while the animals were awake, the effects of CO2 and hypoxia on pH of the film of CSF between the pia and arachnoid (pHMVS) were recorded along with end-tidal PCO2 and PO2 (mass spectrometer), ventilation (pneumotachometer) through a permanent tracheostomy, and, when possible, ear arterial O2 saturation (SaO2). High PCO2 acidified MVS as expected: delta pH MVS/delta log PCO2. = -0.64 +/- 0.14, producing a ventilatory response slope delta VI/delta pHMVS = 372 l/min. Hypoxia resulted in acid shifts even when PCO2 was allowed to fall. The development of hypoxic acidosis was related to the location of pH electrodes determined at necropsy. In isocapnic hypoxia, pH over putative chemoreceptor surfaces fell in proportion to desaturation: delta pHMVS = 0.0033(SaO2)-0.34, r = 0.80, Sy.x = 0.025. With uncontrolled arterial PCO2, similar acidosis occurred when SaO2 fell below 85–90%: delta pHMVS = 0.0039(SaO2)-0.34, r = 0.88, Sy.x = 0.032. With constant hypoxia, pH fell (tau = 3.7 +/- 2.2 min) to a plateau after 10–20 min and showed rapid recovery (tau = 2.0 +/- 1.3 min).(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals The infra-red secondary spectrum of hydrogen

1926 ◽  
Vol 112 (760) ◽  
pp. 196-212 ◽  
Keyword(s):  
Diffraction Grating ◽  
Capillary Tube ◽  
Internal Diameter ◽  
Large Glass ◽  
Glass Bulb ◽  
Infra Red ◽  
The Many ◽  
Disc Electrodes ◽  
Accurate Record ◽  
Aluminium Disc

The first observations of the "many lined" spectrum of hydrogen in the infra-red made by Croze, who measured the wave-lengths of 72 lines between 6838 Å. U. to the nearest on the Rowland system. Porlezza measured the wave-lengths of 43 lines between H a , though his plates were treated to record up to 8000 Å. U. Croze corrected some of his earlier lines and added some 27 more, but did not extend the further limit beyond 8027 Å. U., and his later results were still only given to the nearest integer. As Merton and Barratt had investigated the secondary spectrum only for wave-lengths less than H a , it was thought desirable to re-investigate the infra-red region, to obtain a more accurate record of the wave-lengths of the lines, and to push the limit, if possible, to longer wave-lengths. A plain diffraction grating spectroscope fitted with quartz lenses was used. The grating had 14,500 lines to the inch and gave a dispersion of 25 Å. per mm. An H-shaped vacumm-tube, fitted with aluminium disc electrodes at the heads of the upright stems, contained hydrogen, and to one stem of the tube a large glass bulb was sealed, so that a considerable volume of gas was available at about 2 mm. pressur. The capillary tube connecting the stems was 2 mm. internal diameter, and light emerging from the end of this tube parallel to the tube was directed on to the slit of the spectroscope with a quartz lens. In this "end-on" position the intensity of the secondary spectrum was at a maximum.

The action of magnetised electrodes upon electrical discharge phenomena in rarefied gases. Preliminary note

1899 ◽  
Vol 64 (402-411) ◽  
pp. 172-176 ◽  
Keyword(s):  
Electrical Discharge ◽  
Rarefied Gases ◽  
Preliminary Note ◽  
External Stimulation ◽  
Soda Glass ◽  
Iron Electrodes ◽  
Glass Bulb ◽  
Residual Gas

The experiments herein described were undertaken in order to ascertain what would be the action of strongly magnetised electrodes upon electrical discharge phenomena in rarefied gases, and especially upon the charged residual gas, when all external stimulation had ceased. For this purpose an apparatus was constructed, as shown in Fig. 1, consisting of a soda-glass bulb, B, open at both ends for the purpose of inserting the pointed soft iron electrodes, E 1 and E 2 , and with the leading tube L attached for connection to a Sprengel air pump.

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