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In a previous paper (‘Philosophical Transactions,’ A, 1897, vol. 189, p. 137) we have drawn attention to the fact that the disturbance set up in a liquid by the impact of a rough sphere falling into it, differs in a very remarkable manner from that which follows the entry of a smooth sphere. In the present paper we describe further experiments, made with the object of ascertaining the reason of this difference, and give the conclusions reached. It appeared desirable, in the first place, to take instantaneous photographs of the disturbed liquid below the water-line. These were easily obtained by letting the splash take place in an approximately parallel-sided thin glass vessel (an inverted clock-shade) illuminated from behind. The liquid surface when undisturbed was about level with the middle of the camera-lens, which was focussed for the sphere when under water. The general arrangement of the optical apparatus will be suffi­ciently understood from the accompanying cut (fig. 1). The method of timing the illumination was that already described ( loc. cit. ).

The collection efficiency of nine types of filter papers for air sampling was determined for monodispersed polystyrene latex aerosols by using a forward light scattering photometer. The aerosols were 0.091, 0.198, 0.365, 0.500 and 1.099 mu m in dia., which flowed through a test filter paper at a face velocity from 4.2 to 200 cm/sec. Toyo No. 660, No. 60 and No. LP filter papers exhibited minimum efficiencies at the face velocity range between 10 and 80 cm/ sec, and in the particle size range between 0.1 and 0.5 mu m. The collection efficiencies of Toyo No. 5A and Whatman No. 41 filter papers were over 95% for all the particle sizes at a face velocity higher than 100 cm/sec. Toyo HE-40, HV- 70, Toyo GB-100 and Gelman E filter papers showed collection efficiencies higher than 99%. The theoretical filter efficiency based on single fiber filtering mechanisms and the effect of neighboring fiber interference on the collection efficiency are also discussed. (auth)

Deposits of coal dust collected on filter paper from airborne clouds have been studied in connexion with their light screening power. This depends on the nature of the paper as well as the size and concentration of the particles. Nine kinds of paper were investigated, two of them in detail. Some idea has been obtained of the qualities necessary in a filter paper in order that the dust deposits will have maximum optical density. Theoretical expressions are derived for light screening according to how the particles are dispersed in the paper. Maximum screening would result if each particle shadowed individually, but this is only possible in very sparse deposits; otherwise, overlapping of the particles has to be allowed for. Diffraction of light by the particles and the effects of diffusion of light in the paper are discussed.

This short paper describes a proposed structure of a broad-band electrooptical modulator and an application of existing microstrip analysis programs to determine dimensions of the structure for a broad-band property. Results of numerical computations indicate that it is possible to obtain a broad-band modulator by using LiNbO/sub 3/ or LiTaO/sub 3/.

ELECTROPHORESIS and ionophoresis on paper are being widely used, and a number of different forms of apparatus for carrying out this technique have already been described. The purpose of this communication is to give further details of an apparatus already briefly described1, which has been used for a considerable time with satisfactory results. While we do not claim that it is superior to other types of apparatus, it has the advantage of simplicity, results are reproducible, and the movement of a given substance varies linearly with time. The cross-section is shown in the accompanying diagram. The apparatus consists of a flat rectangular glass tray in which stands a closely fitting glass frame which carries the paper strip and rectangular ‘Perspex’ electrolyte boxes. The dimensions of the apparatus are not critical, but glass drip-trays from refrigerators are very convenient, the outside measurements being about 35 cm. × 20 cm. × 5 cm. The frame is constructed of two rectangles of glass rod, mounted one over the other, and separated from each other by about 1.5 cm. by means of sealed-on pieces of glass, or by pieces of cork at the corners. The frame stands on short legs to keep the paper away from the floor of the tray. Each electrode box has a hole drilled through the end about 1 cm. above the bottom. This enables electrolyte-levels in both boxes to be balanced prior to electrophoresis, and also permits old electrolyte to be run out and replaced by fresh, should this be desired.

ESTIMATION of microquantities of purines by paper chromatography was first suggested by Hotchkiss1. Later, detection by photographing with an ultra-violet source has amplified the method2. Tennent et al. 3 and others have designed adaptors for the Beckman spectrophotometer to enable direct estimation of the purines from paper chromatograms. This method requires costly instrumentation, and is time-consuming unless an automatic recorder is provided.

VERY recently, Matthias1 has described a modified technique which may be looked upon as a combination of uni-dimensional and circular paper chromatography. In this case, substances to be chromatographed are applied near the edge of a strip of paper, the end of which is made in the form of a cone; thus the substances are at first radially distributed, which results in better separation.

Measuring principle of Bekk's smoothness is analysed and it is clarified that there exists in measuring Bekk's smoothness excessive leakage of air which depends on permeability of paper and the roughness of paper of the opposite side of the tested surface. And so the excessive leakage is measured experimentally to be found out that it can not neglected for determining surface roughness of paper by Bekk's method.A direct reading instrument of smoothness of paper are designed applying a similar principle of air micrometer. Theoretical and experimental analyses show that a flow of air through spaces between a test surface and a flatly finished surface obeys Hagen-Poiseuille's law. From this respect the relation between a value of Bekk's smoothness and pressure drop of the new instrument can be given theoretically.Experimental researches show that the observations of smoothness of paper, which is obtained by the new instrument, coincide with those of Bekk's instrument when they are corrected by estimating the excessive leakage.

In the above-mentioned paper Mr. Ward communicates theoretical and experimental investigations which, as far as they are correct, are in their essential parts already published, and indeed somewhat more completely in three papers by Gouy and ourselves, the latter investigations having been suggested by Professor Kundt. Experiments on the rotation of the plane of polarisation of light by means of interrupted currents, like those of Bichat and Blondlot, are here excluded. Since the above-mentioned papers have not been noticed by Mr. Ward, and are hence probably not well known, it may be of interest to reproduce here their essential contents.

I have studied the visco-elastic properties of paper by vibrating reed method at super low frequency range and I measured, Youngs modulus internal frictional coefficient (viscosity).Youngs modulus and viscosity varies by direction in hand made paper, but Youngs modulus is independent of frequency in the range of low frequency. It reduces as increasing frequency. This viscosity is so-called apparent viscosity so, I will convert it true viscosity by next method let us shearing stressv2lv : frequency, l : length.rate of shear v2l/η I plot v2l, v2l/η I obtain consistency curve.I will regard consistency curve as two kinds straight line.I think this straight line means the true viscosity. Let us those viscosities ηHF (Viscosity at high frequency) ηLF (Viscosity at low frequency). Reasonable solution of these two kinds viscosity ηHEηLFis the problem of future.Youngs modulusEand ηHF, ηLFincrease as reducing its freeness in hand made paper.but increasing process changes by pulp sorts.

Direct exposure to the sunlight causes Japanese-paper to deteriorate its physical qualities.This deterioration appears after about 100 hours' direct exposure.(1) Strength, elasticity and other qualities are weakened.(2) In case of whether bleached or unbleached, the latter are more affected.(3) Elasticity is particularly weakened by exposure.(4) Breaking-length is bigger by 100-200 hour's exposure than by 0-100 hours' exposure.(5) Diffractiveness is remarkably lessened by exposure.(6) Gampi-paper becomes fragile in particular by the sun-light.

Hmax and smoothness were measured by needle touch type unevenness tester and Bekk automatic smoothness tester, respectively, and relation between h and Hmax or smoothness was examined.It was found that h was closely conected with Hmax or smoothness.When thickness of paper was measured in superposition by micrometer, and h was obtained with the formula showed in part 1, thereby the surface condition of paper is briefly known.

When the intricacy of the subject, on which my two last papers have been treating, is considered, it will not appear singular that a few supplementary articles should be given. The compression of the account of the experiments into a small compass, where many material circumstances must be left unnoticed, may throw some obscurity on the results, which can only be removed by examining the subject in a fuller ex­tent, and from various points of view. I hope the following illustration and additional explanations will have the effect of clearing up what may possibly to some appear obscure or doubtful, in either the first or second part of my paper, and serve also to make the conclusions, which in the second have been chiefly supported by prismatic experiments, directly applicable to such as have in the first been made by convex glasses. That the colours in all prismatic phenomena, which have been examined in the 44th, 45th, 46th, 47th, and 48 articles of my paper, are produced either by the interior critical separa­tion arising from the different reflexibility of the rays which cause the blue bow, or by the exterior critical separation arising from the different intromissibility of the rays which cause the red bow, has been so clearly and circumstantially proved that it can admit of no doubt; it may even be con­ceived by some that I have been too particular in giving the precise angles, when we see in the LectionesOptica , Sect. II. Par . 2, page 257, 258, how far Sir I. Newton has explained the blue bow ; but a sufficient reason for this minuteness was to give greater clearness to my explanation of the new pheno­menon of a red bow, which I have with equal precision de­scribed, and which by this means may be, step by step, compared with the production of the blue bow; but a sufficient reason for this minuteness was to give greater clearness to my explanation of the new phenomenon of a red bow, which I have with equal precision described, and which by this means may be, step by step, compared with the production of the blue bow. By this precaution I hoped to anticipate any objection that might occur, such as, for instance, that Sir I. N ewton has also explained the red bow which (it may be supposed) merely the converse of the blue bow. This conception, although N ewton no where speaks of a red bow, seems to be countenanced by what is said after he has shown that the blue bow is caused by the different reflexibility of the rays of light; for as he affirms that the red, orange, and yellow colours are transmitted, he contrives a method of proving it experimentally, by adding a second prism, placed under that which gives the blue bow, and thus making the transmitted rays visible. The full import of this Newtonian experiment will be considered in the following articles.

By the use of Micro-Interferometer Niodel MI, the features of smoothness for various coated papers are observed. These features seem to closely relate with the visual degrees of smoothness of papers.Samples used are varnished art papers, brushed art papers and east coated papers.

A novel technique for the color visual display of two-dimensional electrostatic fields is described. Temperature-sensitive encapsulated liquid crystals in sheet form are bonded to carbon-impregnated conducting paper on which a prescribed electrode configuration has been painted. The joule heating of the conducting paper creates a non-uniform two-dimensional temperature field to which the liquid crystals respond with color changes. Bands of uniform color identify isotherms which under certain conditions correspond to lines of constant electric field magnitude. The technique is applied to the study of various problems in electrostatics and potential fluid flow.

The surface color of paper changes depending on observed angle. Such variations in surface color and their relationship to gloss are examined with the aid of a goniophotometer equipped with an interference filter. The results obtained are as follows:1) The smoother the surface and the more uniform the orientation of the constituent fibers of the sample, the closer the chromaticity coordinates get to the light-source color on the chromaticity diagram, when the sample is measured in a specular reflection direction.In other words, the larger the amount of specular reflection light in the goniophotometric reflection curve, the closer the chromaticity coordinates get to the light-source color on the chromaticity diagram.2) The larger the incidence-receiving angle, the larger the tristimulus values is, when the sample is measured in the direction of specular reflection. When the sample has a rugged surface, the angle which shows the maximum quantity of reflection light may deviate toward the direction larger in angle than the direction of the specular light. In this case, when the sample is measured by a goniophotometer at an angle showing the maximum quantity of reflection light, it shows the maximum tristimulus values.3) The goniophotometric color measured is shown by color mixture between the lightsource color and the object color on the chromaticity diagram.4) When the incidence-receiving angle of a paper is changed, its tristimulus values vary, resulting in color differences.5) When gloss is measured in the direction of specular relation, the angle showing the maximum quantity of reflected light may deviate toward a direction larger in angle than the direction of specular light. It is, therefore, recommended that the gonio-photometric reflection curve of the sample is measured before gloss is examined.

The effect of ohmic and dielectric losses, conductor thickness, and frequency dispersion on the performance of edge-coupled microstrip directional couplers and interdigital filters have been determined in this short paper. The odd- and even-mode attenuation constants due to ohmic losses in the conductor have been calculated using Wheeler's inductance formula. The theoretical results for the characteristic impedance and propagation constants are in good agreement with the experimental results of Napoli and Hughes. Among the parameters that can be calculated from this theory are the isolation, directivity, and coupling coefficients of lossy directional couplers and the midband insertion loss of interdigital filters.

This short paper shows how nonseparable solutions of the Helmholtz wave equation can be used in the synthesis of waveguides and cavities with nonconventional cross section, and also investigates the attenuation and Q factor.

The purpose of this short paper is to construct the dissipation and scattering matrices of lossy junctions in terms of the eigenvalues of the dissipation matrix. This removes the need to rely on inequality relations between the scattering parameters of lossy circulators. The eigenvalues of the dissipation, scattering, and admittance matrices are related. The eigenvalues of the dissipation matrix give the dissipation associated with each possible way of exciting the junction. The ones of the scattering matrix give the reflection coefficients associated with these different excitations. The admittance eigenvalues define in each instance the eigennetworks of the junction. This leads to the definition of the entries of the dissipation matrix in terms of the loaded and unloaded Q-factors of the junction eigennetworks. The scattering matrices of a number of lossy 3-port junctions are also constructed directly in terms of the elements of the eigennetworks.

Research has shown that the determination of absorbed microwave energy as well as the control of environmental parameters are important in relating biological-effect data to, radiation protection. This short paper describes the development of an environmentally controlled waveguide irradiation facility for the exposure of small animals to 2450-MHz CW microwave energy. Integral dose rate is determined without perturbing the microwave field interacting with the irradiated animal.

(1926). Measurements by Means of the Siemens' Dosimeter and the Sabouraud Pastille, And by the Former in Connection with a Tube of Sabouraud Paper. Acta Radiologica: Vol. 5, No. 4, pp. 333-371.

The researches detailed in the present paper were commenced in May 1871. The results arrived at were largely obtained from using the microscope. Similar but less brilliant and more scanty appearances can be obtained with the telescope; but the very high power and ready adaptability of the former confers some advantages not offered by the latter. In both, however, the same principles are illustrated. A cone of rays of small angular aperture having the object-glass for its base in each case engages the eyepiece and emerges parallel, and the eyepieces are similar in each.

(1833). LXIX. Remarks on Sir David Brewster's paper “On the absorption of specific rays”. In a Letter to Sir David Brewster, K.H. LL.D. F.R.S.. The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science: Vol. 2, No. 12, pp. 419-424.

An improved method for the liquid scintillation counting of 14C-phytoplankton material on membrane filter papers is described. The method involves the incorporation of standard 14C-sucrose into the filter, and it clearly demonstrates that the counting efficiency of the sample is affected by the amount of material present. It is concluded that the cells and the membrane filter have a self-absorptive effect that previous methods of counting, using internal and external standardization, cannot have fully detected.

We have made researches in absorbing-quantity, absorbing-velocity and absorbing condition of Japanese paper.As the absorption probes to be the capillary phenomenon between fibres, paper with the smaller closeness has the bigger absorptiveness.Absorbing-velocity is different according to the direction, whether lengthwise or widthwise. Generally speaking, the widthwise is slower than the lengthwise.Absorbing conditions also differ from each other ; in the lengthwise directions the top tapers off, mean while, in the widthwise directions it looks nealy horizontal.Papers of obscure length and width find it uneasy to distinguish the tops of absorption.

Magnetostatic surface waves propagating along the ferrite slab adjacent to a semiconductor are discussed in this paper. Our numerical results indicate that the conductivity of the semiconductor plays an important role in the determination of the dispersion relation in the case of nondrifting carriers. The backward wave appears for a finite value of the conductivity.

As a non-destructive method in the examination of paintings infrared photography has an increasing importance in practical restoration and the study of underdrawings: infrared photographs are frequently compared with x-radiographs for such purposes. Infrared photographs generally show a superposition of the visible image and other elements not differentiated by the human eye, but revealed in the wavelength region for which the infrared film has an extended response. Overpaintings can be discriminated in this way and damaged areas localized; changes in composition and underdrawings can be partially revealed. The image of the elements in the infrared photograph \vhich are also visible to the human eye has a density much superior to that of the specific infrared elements: the photographer has thus to work with very high densities in order to obtain a correct contrast in these elelnents made visible by infrared photography. In this respect the infrared negative contains nlore information than the positive print on paper, which is often incomplete. By using certain masking techniques [1] in which the infrared negative is superimposed upon a positive of a panchromatic film exposed with a red filter, this problem has been solved in part: great differences in density of the negative are balanced with a contrary density, and the visible image is thus annulated. Although this technique emphasizes the specific aspects of infrared photography, it demands an exact and complete superposition of the infrared negative and the panchromatic positive, which is very difficult to achieve when enlargements are required. Frequently in infrared photographs the underdrawing is visible in some areas and invisible in others; utilizing the superposition process may then annihilate the visible underdrawing. In view of these difficulties an attempt was made to obtain reasonable prints of infrared negatives permitting an easy enlargement to the scale of the painting by utilizing translucent photographic paper. This paper (Kodak Kodalith TP) nlust be developed in a normal paper developer until the areas with a high density in the negative have a good definition. In viewing the print in reflected light it appears too dark and foggy. In transmitted light, however, the various densities are well differentiated, allowing a complete 'reading' of the infrared negative. The prints on translucent paper can be studied on a negatoscope together with x-radiographs; as they can be easily enlarged to the format of the x-radiographs a precise comparison is made possible.

IN a letter to NATURE,1 J. R. Ashworth mentioned the use of a stepped wedge of fine quality tissue paper in describing a method of measuring ultra-violet light from the sky, photographically. In a later issue,2 P. W. Cunliffe pointed out that “a step wedge constructed of a diffusing medium, such as thin tissue paper, does not obey the logarithmic ‘law’ which is valid only for transparent media”. It so happens that I obtained data last spring which bear on this subject.

Studying systematically the variations of electrical characteristics of microstrip lines with the width w of the line, the thickness h, and the dielectric constant epsilon/sub r/ of the substrate, we have obtained a perfect linear variation with epsilon/sub r/. Then using a least squares method, we have been able to give an analytical expression of capacitances usable for 1 /spl les/ epsilon/sub r/ /spl les/ 100 and 0.04 /spl les/ w/h /spl les/ 10. The importance of this result is that we can give impedances and phase velocities without any computation.

Modifications to a normal microstrip transmission line are proposed, with the aim of reducing the attenuation constant of the line. The results of a computer analysis of a structure containing multilayers of dielectric show that significant reductions in attenuation appear possible.

The beam mode expansion method used to discuss the distraction problem by an aperture is applied to the analysis of the noise reduction structure consisting of two aperture stops. The incident field is a fundamental wave beam whose amplitude distribution is Gaussian. The transmitted field through the structure can be represented as a sum of beam mode functions and is regarded as a signal. The noise which is originated from the spontaneous emission is added to the incident Gaussian wave beam. The signal-to-noise ratio (SNR) in the output is discussed and optimum conditions are obtained numerically.

The influence of radiation losses on the Q of microstrip resonators is shown for a variety of frequencies, characteristic impedances, substrate materials, and thicknesses. Radiation becomes a dominant factor at higher frequencies, especially for low-impedance lines and thick substrates with a low dielectric constant.

A theoretical study, backed by experimental verification, was undertaken to determine the modal characteristics of quadruple-ridged circular and square waveguides. Field lines for the first few important modes and cutoff frequencies were determined. It is shown that for square waveguides quadruple-ridge loading always decreases the TE/sub 10/-TE/sub 11/ bandwidth whereas for circular waveguides only a small amount of additional separation between the first two fundamental modes may be obtained over a limited parameter range. Symmetrical excitation will not excite the asymmetrical higher-order modes. This feature makes these waveguides acceptable as feeds for wide-band reflector antennas and for similar applications but raises a question mark regarding their use as radiators in wide-band phases arrays.

Losses in microstrip on fused-silica and alumina substrates have been experimentally evaluated for various values of stripwidth. Radiation losses in circuits, commonly used for measuring losses in microstrips, depend on the dimensions of the circuit and affect the total losses considerably. Radiation and conduction losses of open-ended line resonators have been separately determined. These measurements have also drawn attention to discrepancies between published theories and our experiments. The effect of surface roughness upon conduction losses has been measured.

Half-wavelength line resonators are employed to enlarge the bandwidth of a 50-GHz Y-circulator. The bandwidth is successfully increased from 3.5 to 5.5 GHz. The characteristics of the half-wavelength line resonator are described.

The functional forms of the fields in a single-ridge waveguide are presented. Bethe's small-hole diffraction theory is used to determine the coefficient for coupling from various parts of the guide to a Fabry-Perot (FP) resonator. It is shown that frequency-independent coupling over a very broad band is possible, and specific examples are given for the band from 18.0 to 40.0 GHz.

Strong dielectric-constant anisotropy exists in muscle tissue at the lower microwave frequencies. Based on a model derived from tissue measurements, an analysis is carried out for single and multiple tissue layers. Calculated effects of tissue anisotropy on microwave fields and power absorption in the tissues are presented.

The resonance frequencies and the fields of a microstrip double-ring resonator are discussed. It is shown that no pure even or odd mode can be excited on the resonator. Therefore it is concluded that the rnicrostrip double-ring resonator principally cannot be used to measure the phase velocities of the even and the odd modes on a coupled microstrip line.

The reflection and transmission of electromagnetic waves by a slant interface between two dielectric media is investigated. By using suitable Green's functions and a geometrical optics approximation for the field on the dielectric interface, expressions for the transmitted and reflected fields are derived. The approximate results obtained in this manner are compared with the available numerical data and are shown to be fairly accurate for a number of cases of interest.

Carpenter and Livstone's experiments on beetle pupae are repeated and extended. In the experiments conducted, increased incidence of abnormal development occurred due to exposure to microwave energy, both CW and pulsed. This effect was observed at the power level of 8.6 mW/cm/sup 2/. Measurements are reported which specify the microwave environment encountered by the insect.

Mixed mode bandpass filters are described which utilize alternating TE/sub 011//spl deg/ and TE/sub n11//spl deg/ circular waveguide cavity modes. This novel filter configuration exhibits both excellent unloaded Q and spurious mode response characteristics. The use of mixed resonant modes makes possible the design of microwave filters for both in-line side wall connected cylindrical resonators as well as folded planar filter configurations, whereby cross-coupling between selected resonators can be realized.

Operation modes of a waveguide Y circulator with a circular and a triangular ferrite post are investigated both theoretically and experimentally. Field analysis is carried out taking into consideration the field variation along the ferrite axis. Frequencies are calculated by assuming TM modes nearly agree with measured frequencies. It is shown that the circulator action occurs at frequencies where two HE modes interfere with each other, besides occurring at HE mode resonance frequencies. Effects of Teflon spacers on circulator performances are investigated in detail.

The transmission properties of spherical TE and TM modes in a perfectly conducting conical waveguide are treated in detail. To start with, an analytically simple and highly accurate digital-computer based iterative algorithm has been employed to evaluate the eigenvalues associated with the spherical TE and TM modes within the guide irrespective of the flare angle (2alpha/sub 0/) of the conical waveguide (theta < 2alpha/sub 0/ < 360/spl deg/). Subsequently, explicit expressions for the attenuation constant, phase constant, phase velocity, and wave impedance are obtained for the spherical modes transmitted within the guide. Accurate eigenvalues obtained numerically are used to study the variation of attenuation constant, phase constant, phase velocity, and wave impedance as a function of the radial distance from the apex with alpha/sub 0/ as a parameter. Measured data on the phase constant of a conical waveguide for the TE/sub 11/ mode have been compared with the analytical results obtained by calculation and an excellent agreement between the two justifies the validity of the analysis presented. Finally, a study of the phase coherence between the dominant spherical TE and TM modes within the guide is presented which may be fruitfully employed in the design of dual-mode conical waveguides.

The relations are established between the scalar modes in an infinite lenslike medium and the vector modes in a self-focusing optical fiber with a finite homogeneous cladding. It is shown that both the transverse fields and the longitudinal fields of the vector modes can be expressed in terms of the scalar modes, provided the fiber is operated in the core mode region. Otherwise, significant discrepancies could arise. The scalar modes, however, cannot describe the cladding modes which are caused by the index discontintuity at the outer surface of the cladding.

The design, development, and construction of a very compact decade-(1-10-GHz) bandwidth microstrip --8.34-dB coupler are described. Calculations are given for the voltage coupling coefficient and the low-frequency cutoff, and the method of determing the physical dimensions of the circuit is described. Also, the feasibility of a decade-bandwidth microstrip magic tee by cascading two -- 8.34-dB couplers is demonstrated by comparing the actual and theoretical results of a coupler.