Astronomical observations 2 .Prism method 3. Interferometer methods 4. Diffraction grating method 5. Summary of previous work II.Purpose 1. Wave length corrections for temperature and pressure of air 2. Wave length corrections to vacuum III.Experimental method 1. Fabry and Perot interferometer for measurement of n IV.Description of apparatus 1 .General plan 2. Sources 3 .Interferometers 4. Air chamber 5. Pressure gages 6. Constitution of the air 7. Photographic V. Experimental procedure 1. Optical adjustments 2. Temperature regulations 3. Pressure observations 4. Photographic exposures 5. Measurement of ring diameters VI.Reduction of observations 718 1 .Correction to 760 mm 7 2 .Final values of n -1 3. Cauchy dispersion formula 4. Sources of error VII.Applications 724 1. Correction of wave-length measurements made in air at other than normal temperatures and pressures 2 .Corrections for water vapor in the air 3. Corrections to convert to vacuum values 4. Astronomical refraction 5. Optical temperature coefficient 6. Dispersion formulas VIII.
II.The photo-electric cell 512 (a) Description of cell 512 (6) Preparation of cell 513 (c) Voltage-current characteristics 515 {d) Voltage-radiation sensitivity 515 {e) Spectral-radiation sensitivity 515 (J) The auxiliary galvanometer -518 (i^r) The auxiliary electrometer 520 {h) High resistance 521 (?) Source of potential 52 1 (J) Methods of operation 522 III, The selenium cell 526 IV.Photographic radiometry 530 V.
University of Minnesota Ph.D. dissertation. May 1917. Major: Physics. Advisor: Dr. Stratton. 1 computer file (PDF); 29 pages.
Purpose of this investigation 490 , II.Observations ' 490 1.The instrument 490 2. Photographic processes 491 , 3. Spectroscopic results 492 III.General discussion 501 1. Identification of band at wave length .760/x501 2. Distribution of energy in stellar spectra 502 IV.Summary 504 * Dicyanin, a synthetic dye used for sensitizing photographic plates. 1 Coblcntz and Emerson, this Bulletin, 14, p. 167; 1917.2 Throughout this paper X will be used as an abbreviation for wave length.In referring to wave lengths between 0.3 and 1.0 m (3000 and 10 000 angstroms) two or more significant figures will be given without decimal points or units.Thus, X 56 is to be understood as wave length 0.56 m (5600 angstroms); X 560 or X5600 would refer to the same wave length, but would indicate greater accuracy.4S7Bulletin of the Bureau of Standards \Voi.14 X69 (red) .From X69 on toward longer waves this value is halved every 100 angstroms, so that to produce a given sensation of vision 5000 times as much energy is required at X75 as at X56.The inefficiency of the eye for the red rays is, perhaps, not generally recognized, since it has not been emphasized so greatly as in the case of the violet rays by the success of photography.To the eye a continuous spectrum is usually terminated at the red end, not by the lack of energy but by the ineffectiveness of the longer waves in producing vision.This fact has been known, as far as the solar spectrum is con- cerned, since the days of the elder Herschel, and has for many years been inferred to hold true in stellar spectra from the assump- tion that the spectral -energy curve is comparable with that of a black body.Nichols's observations in 1900 showed the exist- ence of considerable infra-red energy, at least for the star Arcturus."The ratio greater than 2 to 1, of the total radiation of Arcturus to that of Vega (stars which by most observers are estimated to be of nearly equal photometric magnitude) indi- cates a proportionately more intense infra-red spectrum for the former than for the letter star." 3 By observations of stars with and without a water screen Coblentz 4 has recently proved that a large fraction of the energy in stellar spectra is of greater wave length than 1.4^(14 000 angstroms).
Gold mineralization during the Late Cretaceous produced an epithermal deposit of the low-sulfur (adularia-sericite) type, consisting of disseminated gold, gold-copper veins, and stockworks in Jurassic volcanic rocks and Upper Cretaceous quartz monzodiorite and quartz diorite intrusions. The host rock of the disseminated deposits is a silica cap, which represents the near-surface expression of the epithermal system, and the ore mineralogy consists of pyrite, gold, and minor cinnabar. Silicic alteration is represented by cryptocrystalline quartz, and argillic and advanced alteration by kaolinite, jarosite, and minor alunite. Fluid inclusion studies indicate that alteration occurred at 100–200°C from fluids with a salinity of 0.5–5 wt% NaCl equiv. These were probably acid-sulfate waters formed by oxidation of H2S at the water table. In veins and stockworks, the ore assemblage consists of pyrite, gold, sphalerite, argentite, galena, electrum, chalcopyrite, copper-sulfosalts, bismuthinite, molybdenite, and cinnabar. Adularia-illite-chlorite alteration is closely connected with the stockorrk and vein mineralization. Alteration assemblage and fluid inclusion studies suggest mineralization by near-neutral alkali-chloride boiling fluids at 225–250°C, ranging in salinity from 1 to 14 wt% NaCl equiv., and pressure estimates based on fluid-inclusion data suggest a depth of 300–400 m below the paleosurface. Fracture permeability, combined with a large geothermal gradient, favored the circulation of fluids and development of the geothermal system that caused the mineralization and associated alteration.El estudio de la geología del Distrito Inca de Oro indica que la mineralización ocurrió durante el Cretácico Tardío, y que corresponde a depósitos epitermales de sulfidización baja. La mineralización consiste en diseminación de Au, vetas y stockwork de AuCu emplazados en rocas volcánicas Jurásicas y rocas intrusivas Cretácico Superior. La diseminación de Au se formó en un cobertura silícic, que representa la expresión superficial del sistema epitermal. La mineralización consiste en pirita, oro y menor cinabrio. La silicificación está representada por cuarzo criptocristalino y la argilización por caolinita, jarosita y menor alunita. Estudios de inclusiones fluídas indican que la alteración ocurrió a temperatures entre 100 y 200°C con fluídos cuya salinidad varía entre 0.5 y 5% NaCl equiv. Probablemente la alteración fue producida por aguas ácido-sulfatadas, formadas por oxidación de H2S en la tabla de aguas. En vetas y stockwork la mineralización consiste en pirita, oro, esfalerita, argentina, galena, electrum, calcopirita, sulfosales de cobre, bismutinita, molibdenita y cinabrio. una alteración adularia-illita-clorita está estrechamente relacionada con la mineralización. La paragénesis de alteración y el estudio de inclusiones fluídas indican que la mineralización fue producida por fluidos neutros alcalino-clorurados en ebullición, en un rango de temperature entre 225 y 250°C, y salinidad entre 1 y 14% NaCl equiv. La presión estimada sobre la base de datos de inclusiones fluídas, sugieren que la mineralización ocurrió entre 300 y 400 m bajo la paleosuperficie. Una permeabilidad estructural combinada con un amplio gradiente geotermal, favoreció la circulación de fluidos y el desarrollo de un sistema geothermal, con la consecuente alteración hidrotermal y mineralización aurífera.
Formulas for the correct and the effective inductance, capacity, and resistance of an antenna are given. The relation of the values given to the corresponding static values is studied. The resul$s obtained are shown to agree closely with the experimentally determined values for a coil-loaded antenna.
This paper gives transmission data in the spectrum extending from o.6n to 3/u, using a mirror spectrometer, a quartz prism, and a vacuum thermopile.The sub- stances examined are a group of mineral, animal, and vegetable oils (containing fatty acids), nitrocellulose, bakelite, and selenite.It is shown that the absorption spectra of the oils are so nearly identical that they can not be used for detecting the adultera- tion of one oil with another.The paper concludes with an examination of the accuracy of the author's previous work using a rock-salt prism.It is found that, using the recently determined refractive indices of rock salt, the corrections to the observations of 1903 to 1905 are of the order of o.oi to o.o2/tt and hence negligible.
II. Thermal expansion of alpha and of beta brass 574 1 .
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTLATENT HEAT OF VAPORIZATION OF AMMONIA.Nathan S. Osborne and Milton S. van DusenCite this: J. Am. Chem. Soc. 1918, 40, 1, 14–25Publication Date (Print):January 1, 1918Publication History Published online1 May 2002Published inissue 1 January 1918https://pubs.acs.org/doi/10.1021/ja02234a002https://doi.org/10.1021/ja02234a002research-articleACS PublicationsRequest reuse permissionsArticle Views674Altmetric-Citations10LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
Introduction 59 II.Sucrose solutions 61 1 Purification of sucrose . . . .61 2 Preparation of solutions 62 III.Measurement of viscosity 64 1.The viscometer 64 2. Viscosity formula 64 3. Calculation of constants in formula 65 4. Calculation of the pressure 65 5. Details in regard to instrument and measurements 69 IV.The Centipoise 72 V. Viscosity and fluidity of water 73 VI.Viscosity and fluidity of ethyl alcohol-water mixtures 76 VII.Viscosity of sucrose solutions 77 VIII.Summary 85 Appendixes 86 Appendix A. -Density in grams per milliliter of mixtures of ethyl alcohol and water 86 Appendix B. -Density in grams per milliliter of sucrose solutions 86 Bulletin of the Bureau of Standards Voi.14determined.But water is ill-suited for the calibration of the short-capillary technical viscometer, since water is so very much more fluid than most oils for which these instruments were intended.In spite of the oft-repeated statement to the contrarv, the viscosities of two substances are by no means directly pro- portional to the times of flow of equal volumes through a given capillary under the same head.The chief cause of this lack of proportionality is the fact that the energy is not all expended in overcoming viscous resistance, a part of it being used up in imparting kinetic energy to the fluid entering the capillary.Thus in the flow of water through an Engler instrument only about 10 per cent ' of the total energy expended is used in overcoming viscous resistance, the remaining 90 per cent being used in impart- ing kinetic energy to the liquid.The presence of so large a kinetic energy correction renders it manifestly desirable to have at hand some substance of high viscosity which can easily be obtained in a pure condition and whose viscosity is accurately known.Castor oil and olive oil have been studied, but it has not been determined to what extent the viscosity may vary with the con- ditions of manufacture and exposure to light and air.No pure hydrocarbon is readily available which possesses suffi- ciently high molecular weight.Monoacid alcohols of high molec- ular weight, like amyl alcohol, are not cheaply and easily obtained in the pure and anhydrous condition.A mixture of 45 per cent by volume of ethyl alcohol and water has a viscosity which is almost exactly four times that of water at o°C.Since the viscos- ity of ethyl alcohol-water mixtures passes through a maximum for this concentration, the viscosity does not change rapidly with the concentration, which is a marked advantage.The viscosities of alcohol and water mixtures have been determined with care by several observers.When more viscous substances are desired, the poly-acid alcohols are available, and of these glycerol is perhaps the best for the purpose.It is, however, hygroscopic and not readily obtainable in the pure anhydrous condition so that the preparation of a solution of predetermined concentration offers some difficulty.The sugars are valuable substances for the purpose.They are not hygroscopic; they are crystalliz able so that they may easily be obtained in a very pure condition.The concentration of sucrose 1 Obtained by substituting the dimensions given in Ubbelohde's Tabellen zum Enqlerschen Viskosimeter, p. 24, in our equation (;) assuming the viscosity of water at 20 to be 0.01005 and the time of flow to be 51 seconds.
II. Luminous flux emitted by a black body 356 III.Radiant luminous efficiency of a black body 359 IV.Mechanical equivalent of light determined from black-body radiation. . .360 V. Radiant luminous efficiency of a tungsten lamp and the mechanical equivalent of light 363 VI .
To critically review developments over the first fifty years of research (1967–2017) on (a) how people feel when they participate in exercise and physical activity, and (b) the implications of these responses for their willingness to become and remain active.Non-systematic narrative review.Representative sources were selected through a combination of computer searches and cross-referencing.For over three decades, exercise psychology exhibited a fixation on the idea that exercise and physical activity make people feel better. This notion, however, seemed to contrast with evidence that most adults in industrialized countries exhibit low levels of activity. In the last two decades, a critical examination and overhaul of the methodological platform resulted in the delineation of a dose-response pattern that encompasses positive as well as negative affective responses, and revealed marked interindividual differences. An emerging literature is aimed at refining and testing integrative dual-process models that can offer specific predictions about the behaviors that may result from the interaction of automatic processes (theorized to be heavily influenced by past affective experiences) and deliberative processes (such as cognitive appraisals).Affective responses to exercise and physical activity are more complex than the long-popularized "feel-better" effect, encompassing both pleasant and unpleasant experiences and exhibiting marked interindividual variation. The potential of affective experiences to influence subsequent behavior offers an opportunity for an expanded theoretical perspective in exercise psychology.
Report issued by the Bureau of Standards over the measurements of critical ranges of pure iron wire. The methods and materials used for the measurements are discussed. This report includes tables, and illustrations.
Introduction i68 II.Methods for dktkrmining the visibility of radiation i68 1. Threshold of vision i68 2 .Visual acuity 3. Critical frequency 4. Equality of brightness 5.The flicker photometer III.Apparatus and methods 1.The spectrometer lenses 2. The prism 3. The light sources 4. The energy measurements 5.The Nicol prisms 6.The flicker photometer 7. Methods of observation IV. Discussion of data 1.Total color blindness 2. Partial color blindness 3. Red sensitiveness 4. Blue sensitiveness 5. Green sensitiveness 6. Red-blue sensitiveness 7. Subnormal blue sensitiveness 8. Subnormal red sensitiveness 9. Average color vision 10.Remarks on observational data. 1 1 .Fatigue and adaptation 12 .Flicker versus equality-of-brightness measurements 20S 13.Effect of age upon visibility V.The visibiuty curve of the average Eye VI.Some practical applications to radiation problems 1.A visibility of radiation equation 2. The minimum radiation visually perceptible VII.Summary Appendixes Appendix i.On diffuse light and spectral-energy measurements EmZ%\ i?e/a/z2;e Visibility of Radiation 169 ' §tf«pqp^'3Pij^0^363 CO CO ^CO CO H ^H w p; h; CO fe, f^P P', pj p4 p4 Q ^S eC 2 i^-CO S ^' ^.
Human embryonic stem cells (hESCs) are derived from the inner cell mass of the blastocyst. Despite sharing the common property of pluripotency, hESCs are notably distinct from epiblast cells of the preimplantation blastocyst. Here we use a combination of three small-molecule inhibitors to sustain hESCs in a LIF signaling-dependent hESC state (3iL hESCs) with elevated expression of NANOG and epiblast-enriched genes such as KLF4, DPPA3, and TBX3. Genome-wide transcriptome analysis confirms that the expression signature of 3iL hESCs shares similarities with native preimplantation epiblast cells. We also show that 3iL hESCs have a distinct epigenetic landscape, characterized by derepression of preimplantation epiblast genes. Using genome-wide binding profiles of NANOG and OCT4, we identify enhancers that contribute to rewiring of the regulatory circuitry. In summary, our study identifies a distinct hESC state with defined regulatory circuitry that will facilitate future analysis of human preimplantation embryogenesis and pluripotency.
