Search

The Raman spectrum of gaseous N2F4 at a pressure of 760 Torr was recorded with a spectral slit width of 3 kaysers. Ten of the expected eleven fundamentals of the symmetric motions of both the gauche and trans isomers give rise to strongly polarized Raman lines. These new data require a reassignment of some of the fundamentals for both the C2 and C2h conformers. The Raman of the solid at 18 K was also recorded. Both conformers were found in the solid even after annealing the sample for 9 hr at a temperature of 101.6 K and 3 hr at a temperature of 106.8 K. Bands attributable to the gauche isomer became more intense relative to those for the trans isomer after several hours of annealing.

1. 1. Some confusion has recently developed concerning the “correct” molar absorptivity (e) for use with the Ellman reagent, 5,5'-dithiobis (2-nitrobenzoate). 2. 2. For any compound E is dependent upon the experimental conditions under which it is determined and is correct for that system alone. 3. 3. General acceptance and use of a single reported value is invalid and can lead to inaccuracies. 4. 4. In support of this we discuss the effect on e of slit width, stray light, wavelength and photometric accuracy and the presence or absence of the parent compound in the analytical solution. 5. 5. We conclude that for any colorimetric reagent, a single “correct” e value should not be sought but rather that internal standardization should be the rule.

The L-absorption spectra of Sm in the metal and some of its compounds have been recorded for the first time. The spectra. have been recorded photographically using a 40 cm bent crystal X-ray spectrograph, kept inside a vacuum chamber. The white lines have been observed at the LIII and LII edges of Sm in the metal and its compounds and their occurrence have been attributed to the transition from 2p states to the vacant part of 5d bands. The values of the various parameters, used to define the position and size of the white line, have been presented. An empirical relation between these parameters has been established. The effective slit width of the spectrograph has been found to be about 10 eV from this relation. Die L-Absorptionsspektren von Sm im Metall und in einigen seiner Verbindungen wurden erstmalig aufgenommen. Die Spektren wurden mit einem gebogenen 40cm-Kristall-Rontgenspektrograph im Inneren einer Vakuumkammer registriert. Die weisen Linien wurden an den LIII- und LII-Kanten des Sm im Metall und seinen Verbindungen beobachtet und ihr Auftreten wurde dem Ubergang von 2p-Zustanden zum leeren Teil des 5d-Bandes zugeordnet. Die Werte der verschiedenen, zur Definition der Lage und Grose der weisen Linien benutzten Parameter werden mitgeteilt. Es wird eine empirische Beziehung zwischen diesen Parametern aufgestellt. Eine effektive Spaltbreite des Spektrographen von etwa 10 eV wurde aus dieser Beziehung gefunden.

Converging cylindrical detonations are produced using a Perry-Kantrovitz-type experimental apparatus. The usual straight detonation tube is followed by the converging part, with the intermediation of the diverging part containing a cone. The converging part is 130 mm in diameter and 2.4 mm in depth. Equi-molar oxyacetylene mixtures at 28 Torr are adopted to produce the most stable detonations. It is observed that at higher pressures triple-shock intersections propagating in the in-depth directions and appearing when the detonation curves along the periphery of the converging section are not damped, whereas at lower pressures the reproducibility of the location of the collapsing center is deteriorated. In both cases the scatter of the geometrical collapsing center has exceeded the slit width adopted. The rotational temperature is measured by the multi-line method using CH 4315 A system (0,0) R branch, where the obscuring effects of continuous and other spectra are small. The measured temperature is about 20,000 ± 10,000°K, which is closer to those measured by Belokon et al. and Huni than to those by Knystautas et al. and Roberts et al. The scatter of the data is caused by the slight deviation of the collapsing point from the predicted one where the slit is located.

The high resolution infrared spectra of 10 BD 3 CO and 11 BD 3 CO were obtained in the region of the ν 2 fundamentals. The K = 0 subbands of the ν 2 and ν 2 + ν 8 − ν 8 bands were assigned. The K structure is unresolvable with a spectral slit width of 0.03 cm −1 . A series, almost as strong as the main series, has been identified in the spectrum of the 11 B molecule but has not been assigned. It is shown that the four structural parameters of borine carbonyl cannot be accurately determined using only the B 0 rotational constants of four isotopically substituted molecules.

An interferometric technique for measuring the spectral slit width of i.r. spectrophotometers has been described. This method involves the evaluation of the visibility of the interferences of a Fabry-Perot interferometer observed in the spectrophotometer. The reflexion of the interferometer plates approximates to R = 0.41. The profile of the slit function is assumed to be the Gauss curve. However, measuring conditions can be given, for which the measurement result is rather independent of this assumption.

The stochastic method of analysis of band spectra of asymmetric rotors involves the calculation of line strengths and positions for successive estimates of six molecular constants, until the calculated intensities at all wave‐lengths agree satisfactorily with the observed. This paper shows that these extensive calculations, as based on tables previously published, are well adapted to standard punched‐card equipment. In addition to the above calculations, it is possible to construct the appearance of the rotational structure for various values of slit width. The procedure is carried through for H2S with some approximate constants. Very satisfactory representations of observed spectra are obtained for completely resolved spectra, as in the photographic region; for slit width 1 and 2 cm−1, as in the near infra‐red; for slit width 10 cm−1, as in poorly resolved infra‐red spectra.

This work is a beginning attempt to determine how the properties of the process of measurement limit the maximum attainable knowledge of the value of a measured quantity. The problem considered here is whetherboth the scale pointer reading errors must approach zeroand the number of observations approach infinity in order to know the exact value of a measured quantity or whether just the number of observations must approach infinity. After a preliminary discussion of the methods of treating experimental data and their relation to reading errors, the measurement of the width of a slit is discussed in some detail. A single measurement consists in placing an opaque sheet containing the slit on an array of detectors, illuminating the system with a strong source of light and counting the number of altered detectors. It is found that, at best, the uncertainty in the measured width of the slit is an. interval equal to the width of the smallest detector used. Consequently in order to determine exactly a slit width at least the detector width roust approach zero. It also turns out that under conditions often used for such measurements the number of observations must approach infinity.

Half maximum breadth (Bo) of a diffraction profile of carbon increased with the increase of sample thickness. When sample thickness was less than 0.2mm, Bo value came closely to the value obtained by the reflection only from the surface. When silicon powder was used as an internal standard, Bo value of (002) diffraction line was almost constant regardless of sample thickness. But Bo value of (004) and (110) lines showed still some broadness due to penetration of X-ray beam into sample, even if silicon powder was used as an internal standard. Therefore, it is concluded that it is preferable to use sample thickness less than 0.2mm and to use slit width as small as possible in order to reduce low absorption effect of the sample.Shape of (00l) diffraction profiles was also affected by the reflection from an internal well-oriented layer in the sample which might be produced during mounting process. If the internal well-oriented layer is made at a distance from the rotation axis, the reflection from the layer appears at displaced position, and the reflection overlaps the profile which is reflected from surface layer.

The spectrum of the night sky from 1.0 to 2.0 μ has been obtained, using a scanning spectrometer equipped with a PbS cell detector. The spectral slit width employed varies from 100 A to 200 A. It has been concluded, from a comparison with synthetic spectra, that the observed spectrum must arise predominantly from the rotation-vibration bands of the OH molecule.

Synopsis The measurements of Winkel, Broese van Groenou and Gorter on the heat conduction in liquid helium II have been extended to lower temperatures. At 1.1 and 1.2°K the heat conduction still appears to be proportional to the cube of the slit width h in not too narrow slits. The viscosity computed from these data thus appears to have physical significance. There is a tendency for the viscosity to rise at the lowest temperatures but this effect is not so pronounced as has been found in oscillating disc and rotating viscometer experiments. No Knudsen or Klemens effects have been found.

The theory of comatic spectral lines is developed in the Seidel approximation and the results of the theory are applied to the interpretation of experimental data obtainable from focus tests by the method of separation of beams. It is shown that this technique, in conjunction with the theory, allows us to evaluate the performance of any spectrograph where coma is the major aberration. The method is thus particularly suitable for use with the Wadsworth mount of the concave grating and the stigmatic mounts of Ebert and Czerny—Turner types for the plane grating. A theoretical result of particular interest is a quantitative estimate of coma limited slit width, which restricts the validity of van Cittert's criterion in the presence of coma.

A preliminary note with regard to our finding of chromium in certain human tumors was published in 1932 (1) and a detailed description of the new technic for the determination of transmittancy was given in a recent communication (2). The present paper deals with the application of this method to the quantitative determination of chromium in certain human tumors. In the above mentioned note it was pointed out that chromium could be determined in the presence of iron from transmission values at wavelengths between 5040 A and 5800 A. In order to choose the most suitable spectrum lines for use in determining transmission values in this region, microphotometer (Moll type A) record was made of a tungsten spark spectrogram. The air lines 5045 A and 5710.7 A gave records that were sharp and sufficiently distant from neighboring lines to be satisfactory for this purpose. A series of spectrograms was made using various slit widths. An investigation of the microphotometer records of the lines mentioned led to the choice of 0.05 mm. slit width as being the most desirable. The length of exposure time was determined from the characteristic curve to the Wratten M plates used. Fifteen seconds was found to be the longest exposure time that produced density values falling on the straight line portion of the curve, and this was accordingly chosen as the standard time.

A spectrochemical procedure to determine the ratio of the concentration of argon in a sample slightly different from air to the concentration of argon in air was developed using an electrodeless discharge tube and a 22-foot direct-reading optical spectrometer. A precision of ±0.43% at the 95% confidence level was obtained for a single determination made in 1 minute. A method of relative precisions to obtain optimum adjustments of the equipment is described. This method was used to determine the optimum discharge tube pressure and the optimum entrance slit width.

1. The discharge frequency of simple neurones in the cat striate cortex responding to the two edges of a slit of light moving over their receptive fields was studied as a function of slit width. While one edge of the slit was discharging the cell, the other edge had a modifying influence on that discharge either by way of facilitation or of inhibition.2. The most common form of the curve relating discharge frequency and slit width had a maximal discharge at narrow slit widths (< 0.5 degrees ) and relative inhibition at medium widths (between 0.5 degrees and 2 degrees ). At greater slit widths there was usually a region of facilitation before the effects of the two edges became independent of one another. Three other response patterns to slits of different width are described.3. The curve relating slit width and response amplitude for a particular cell provides an important clue to the various activity profiles for that cell. An activity profile plots the excitability of a cell along a line through the receptive field in the direction of stimulus movement. Each type of edge, light and dark, has its own set of activity profiles which differ depending upon stimulus parameters such as the direction of the movement of the edge.4. Two other methods were used to provide further data concerning the activity profiles and as a check on the evidence provided by the responses to slits of different width. One of these two methods used the test stimulus against the background of an artificially produced maintained discharge and the other involved the interaction of the two receptive fields of binocularly activated cells.5. A model is put forward to explain the receptive field organization of simple striate neurones which takes into account not only the main features of what is known concerning the synaptology of the visual cortex but also the new data provided by the present paper and the one which precedes it.

The E1cm.1% values of infra-red absorptions of picolines in cyclohexane solution vary with the concentration of the solutes. Variation of the E values due to slit width effects is not the only factor contributing to the failure of Beer's Law; a second factor is interaction between the solute molecules. Serious errors in infra-red absorption analysis of picoline mixtures are demonstrated when such interactions are not taken into account.

1. The purposes of this investigation were to obtain quantitative data on the photoreactions that prevent flowering of short-day plants, from which an action spectrum relating wave length to photoperiodic effectiveness of light could be derived, and to draw such inferences concerning the nature of the photoreactions as the action spectrum would permit. 2. Experiments designed to give the action spectrum made use of a specially designed prism spectrograph having a dispersion of 15 A. per cm. at 5000 A. At this wave length and with an effective slit width of 100 A. the energy was about 3000 ergs per sq. cm. per second with the slit illuminated by a carbon arc operated at 12 kw. input. 3. Plants investigated were soybean, Soja max (L.) Piper var. Biloxi, and cocklebur, Xanthium saccharatum Wallr. To facilitate irradiation, the foliar surface of the plants of each species at the beginning of an experiment was reduced to a single leaflet or leaf, respectively. 4. The experimental treatment was based on the fac...

The measurement of stressss by x-ray methods is usually considered to gain in precision as the backreflection angle is reduced. This result is true only if the line width is effectively determined by the slit width and is therefore independent of the angle. If, however, the main cause for the observed line width ie stress inhomogeneity, or if there is an appreciahie instrumental uncertainty in the readings of the line position, then the error in the relative change of the interplanar distance is independent of the back-reflection angle and of the distance from the sample to the plane film. The possibility of determining stresses by means of fairly wide lines removes hitherto embarrassing restrictions on the application of the method. (auth)

Flame photometric determination of 0.001% Na in primary standard potassium iodate by applying the “ Linear Extraporation Method ” is reported.By reason of the working curve of Na in 1% KIO3 solution being linear up to 1 p.p.m. Na content and its background flat, the above method becomes applicable.Under the condition of oxygen pressure 13 psi, acetylene pressure 3.5 psi, slit width 0.02 mm, and by using Beckman DU flame photometer with photomultiplier, 0.001% Na in KIO3 was determined with good precision. If sufficient care is taken to prevent the intrusion of Na, this method is more simple and more rapid as compared with the usual method.

The mechanism of discharge of a cohesive solid from a vibrating hopper is studied using a simplified block-flow model. The model is used to derive a flow criterion and a flow rate equation for a two-dimensional hopper. Confirmatory experiments have been performed in which the moisture content of powder, the slit width of the hopper and the frequency of vibration were varied. The results show that a vertical sinusoidal vibration of low frequency is most effective in promoting flow from a blocked hopper.

A spectrophotometric method for the determination of plutonium in the range of 0.2–140 mg/1 is described. The method is based on the measurement of the absorption of plutonium (VI) at 831 nm. A recording spectrophotometer with variable slit width, 10-cm cells and scale expansion facilities, is necessary. Uranium up to 20 g/1 does not interfere.

Determination of the relative transition probabilities for lines 2 to 16 in the principal series of sodium.---Direct measurement of line absorption intensities was made by a precise method of photographic photometry previously described. On each plate 11 spectra were photographed, 5 absorption spectra of light from an aluminum underwater spark which had passed through 10 cm of vapor, and 6 calibrating spectra of a constant cadmium spark. Corrections were applied for densitometer slit width, plate characteristics, band absorption, and sensitometer slit width and dispersion curve. The doublets were unresolvable at the vapor pressures used and were treated as single lines. Line shapes were measured at 18 different vapor densities, covering a four-fold variation, and from these were determined the constants ${C}_{1}$ and ${C}_{2}$ in Slater's formula for transition probabilities as given by his theory of virtual oscillators, $\mathrm{Nxh}{\ensuremath{\lambda}}_{0}{B}_{\mathrm{ij}}=c\ensuremath{\pi}{log}_{e}10\ifmmode\times\else\texttimes\fi{}\sqrt{\frac{{C}_{1}}{{C}_{2}}}$, and the relative transition probabilities ${B}_{\mathrm{ij}}$ for the various lines 2 to 16. No decrease in relative probability of the higher numbers with increasing vapor pressure was found, the curves for ${log}_{10}N{B}_{\mathrm{ij}}$ as a function of term number for different pressures being practically parallel. From the smoothed curves average relative values of ${B}_{\mathrm{ij}}$ were obtained with a variation of 2 to 4 percent, and from these the corresponding relative values of ${A}_{\mathrm{ij}}$ were calculated from Einstein's relation ${c}^{3}{A}_{\mathrm{ij}}=8\ensuremath{\pi}hv_{0}^{}{}_{}{}^{3}{B}_{\mathrm{ij}}$. Hoyt's preliminary theoretical calculation of the ratio of the first two terms was found to agree closely with these results.

The aim of this paper is to study, with the help of electronic computers, the relations between maximum true optical densities ( D 0 ) vrai and true widths B vrai of infra-red absorption bands on one hand, maximum apparent optical densities ( D 0 ) app and apparent widths B app on the other hand, when some laws (Lorentz function; triangular slit function) are assumed to be valid. We at first explain the mathematical methods used for this purpose. We then give the results obtained in the range 0 ⩽ s / B app ⩽ 0·95 and 0 ⩽ ( D 0 ) app ⩽ 1 ( s = spectral slit width), paying particular attention to the slit range s / B app ⩽ 0·65 for which computations were previously hand-made by Ramsay and (independently from him) by Pirlot, and for which the present work makes a choice about divergences found between the results obtained by these two authors. Finally, from the results of our study, we suggest two simple graphical methods allowing, the former to compute integrated absorptions, the latter to determine B vrai in case s is not known with sufficient accuracy.

The band (v 1 + v 4) of gaseous HCCl3 has been remeasured with a spectral slit width of about 0,06 cm-1. By using the technique of computer simulation the following constants have been evaluated: (v 1 + v 4)0, α C (1+4), α B (1+4) and ξ Z (1+4).

The infrared absorption due to localized vibrations of H− and D− ions in NaF and LiF is measured between 20 and 300 °K. The oscillator strengths are temperature independent. Measurements with uniaxial pressure show that the frequency of the local mode in NaF:H− is shifted by lattice distortions of the symmetry of Γ and Γ but not of Γ. In NaF:D−, LiF:H−, and LiF:D− two-phonon decays are allowed resulting in relatively large halfwidths at low temperatures. In NaF:H− a two-phonon decay is not possible and the halfwidth becomes smaller than the minimum spectral slit width of the grating spectrometer. The temperature dependence can be described by a scattering process in NaF:H− and by a composition of a scattering process with a two-phonon decay process in the other systems. The anharmonic frequency shift is calculated to a first approximation. In a simple density approximation the side band spectra can be described better by anharmonicity than by nonlinear dipole moments. Die Ultrarotabsorption lokalisierter Schwingungen von H−-und D−-Ionen in NaF und LiF wird zwischen 20 und 300 °K gemessen. Die Oszillatorenstarken sind temperaturunabhangig. Messungen mit uniaxialem Druck an NaF:H− zeigen, das die Frequenz der lokalisierten Schwingung durch Gitterverzerrungen der Symmetrien Γ und Γ, aber nicht durch Γ verschoben wird. In NaF:D−, LiF:H− und LiF:D− sind Zweiphononen-Zerfallsprozesse erlaubt, so das man bei tiefen Temperaturen relativ grose Halbswertsbreiten erhalt. In NaF:H− ist ein solcher Zerfall nicht moglich, und die Halbwertsbreite wird kleiner als die spektrale Spaltbreite des Gitterspektrometers. Der Temperaturverlauf kann in NaF:H− durch einen Streuprozes, in den anderen drei Systemen durch Uberlagerung eines Zweiphononen-Zerfallsprozesses mit einem Streuprozes erklart werden. Die anharmonische Frequenzverschiebung wird in erster Naherung berechnet. Mit einer einfachen Dichtenaherung konnen die Seitenbanden durch Anharmonizitat besser beschrieben werden als durch nichtlineare Dipolmomente.

Synopsis Further experiments are carried out on the flow of liquid helium II in an annular flat slit, with a length of 0.134 cm. The slit width varied between 0.4–6 microns. The frictional force F, defined as the difference between the observed and theoretical fountain effect, was studied in its dependence on the (relative) velocity v. It was found to vary with a power of this velocity, which in most cases was not very different from three. Comparison of the absolute values of the frictional forces with those obtained earlier in a longer slit (0.434 cm) indicates that the forces are roughly proportional to the slit length. This result suggests that the friction phenomena do occur in the whole slit and not only at the (narrowest) entrance.

Although the Davis Halide Meter is one of the best portable instruments so far encountered for the evaluation of health hazards which may result from the inhalation of organic chloride vapors, it has not been completely free of difficulties. These problems are described along with corrective measures which have been developed. A partial list of items considered includes: effect of water vapor, inability to zero the instrument, effect of slit width, effects of high concentrations of organic halide vapors upon subsequent use and required calibration.

THE development of the roentgen kymograph and its increasingly important position in x-ray diagnosis make it desirable at this time to correlate the physical principles underlying the method. This is peculiarly important in this field which is primarily concerned with a physical process movement. Slit kymography is essentially a process in which an image of a moving object formed by any type of radiation is permitted to fall upon a screen opaque to the radiation and bearing one or more transparent slits. A surface sensitive to the radiation is moved past the slit, or the slit-bearing screen is moved past the sensitive surface. The developed image is the kymogram.2 Fundamental Considerations.—We shall designate the slit width by s (cm.) and assume that the movement of the film is in a direction at right-angles to the slit and with constant speed v (cm. per sec). Every point of the film which passes the slit is exposed to the ray during a time equal to s/v seconds. This may be called the characteristic time...

The contribution of diffraction to the limit of resolution at various slit widths has been derived. The resolving power at slit width “S” has been shown to be given by the relation R8 = R0[δ + h(δ)] where R0 is the resolving power for slit width zero and δ = [(S2f)(λ|D)]. h(δ)(ν/R0 represents the contribution of diffraction to the limit of resolution in cm−1.

The influence of the optical system of four microphotometers viz. Zeiss, Leeds and Northrup, A.R.L. and Optica Milano on the plate calibration curve of a photographic plate is described. The following general conclusions are reached: (1) That, when the Zeiss and Optica Milano instruments are used for the blackening determination of spectrum lines the slit width of the detector must at least be a sixth of the width of the projected image of the spectrum lines, which are being measured. These instruments show little stray light effects, when measuring weak lines but for intense lines stray light effects must be taken in to consideration. (2) When using A.R.L. instruments it is very important to use a slit which is about a third of the width of the spectrum lines which are being measured. (3) Of the instruments tested the Leeds and Northrup instrument has the least amount of stray light. This means that a very limited amount of stray light is dispersed in the optical system of a microphotometer when (a) the light source is a strip filament of restricted diameter; (b) the image of the light source formed in the gelatine layer of the photographic plate is at least a third of the absolute width of the weakest spectrum lines.

The experimental and theoretical factors influencing the measurement of the profiles and intensities of infrared absorption bands for materials in condensed states are reviewed. The effects of the spectral slit function and of the time constants of the spectrophotometer recording system on the band shape are discussed, and the methods available for the experimental evaluation of these quantities are described. The theoretical and experimental problems associated with the determination of the true band-intensity parameters from the corresponding apparent band-intensity parameters are examined critically and the interrelationships among the various spectrophotometric variables, including spectral slit width, amplifier time constant, scanning rate and amplifier gain are considered both in terms of the theory of errors and with respect to general laboratory practice.

The effect of spectrometer slit width upon the shapes of some vibrational absorption bands in solution was examined and the applicability of Ramsay's direct integration method for intensity measurement was discussed. The 1737-cm −1 band of ethyl caproate, the 1216-cm −1 band of chloroform, and the 878-cm −1 band of 1, 2, 4, 5-tetrachlorobenzene in nonpolar solvents, all shapes of which are close to Lorentzian, were observed under various conditions. It was concluded that Ramsay's direct integration method applied with adequate care is useful for intensity measurement satisfactorily within experimental error, when the band in question is Lorentzian or nearly Lorentzian.

Experiments on the two-dimensional flow of sand were carried out to investigate the flow behavior of granular materials in a container.Following results were obtained from the observation of the non-steady flow boundary.(1) Container width B does not affect the shape and development-rate of the flow boundary (Figs. 8, 11, 15).(2) Container depth L produces the remarcable effect upon the flow region (Fig. 10).(3) Slit width S has no effect upon the shape of the flow boundary.(4) An expression giving the shape of the flow boundary is presented in Section 2.6.

In a generalization of Guinier's approximation, the scattering functions in small angle scattering are represented by series of Hermite orthonormal functions. This allows a general solution of the slit height problem in terms of a simple coefficient formalism. To correct the slit width resolution error and the polychromatic effect on the basis of Hermite functions, orthonormal systems are constructed which lead to recurrence relations for the coefficients appearing in the solution. The methods have been numerically tested for various types of functions.

Measurements of the spectra of the night airglow emission in the 1.40–1.65 μ region have been made at a spectral slit width of 25 A, with a grating spectrometer using a germanium photoconductive detector. The rotational fine structure of the 3,1 and 4,2 OH bands was partially resolved and the 2,0 OH band was observed for the first time. Rotational temperatures between 200 and 225°K were obtained from the P-branch of the 3,1 band. A mean value of 66 kR was obtained for the absolute zenith brightness of the 4,2 OH band. A van Rhijn measurement of the height of the OH emitting layer gave a value of 69 km.

The experimental determination of the resolving power of infrared spectrometers by means of sharp absorption lines is discussed. Under certain conditions the convolution of the true line profile with the monochromator function approximates completely to the latter, from where the spectral slit width can be obtained immediately. Some suitable lines in the absorption spectra of small gas molecules are suggested for calibration purposes.

The analysis of the pure rotational spectra of symmetric top molecules with unresolved K-structure is discussed. Expressions are derived giving the displacement of the observed peak maxima from the K = 0 lines using two approximations. The first, valid at large spectral slit widths, assumes that the observed maximum occurs at the center of gravity of the component K-lines. The second takes into account the effect of spectral slit width on the band contours. Both approximations yield rotational constants for NT3 which are in closer agreement with those obtained from rotation-vibration analyses than were the original far-infrared constants reported by McDowell and Jones, but the second approximation gives a much better statistical agreement. It is shown that when the second approximation is used, DJK can be obtained from far-infrared data even when the K-structure is not resolved. For NT3 the treatment yields DJK = −(12 ± 4) × 10−5cm−1, in good agreement with the theoretical value.

A rapid sensitive (1 p.p.m.) ultraviolet method of analysis has been developed and successfully applied to the determination of repellent in cloth and on glass plates. The absorbance of a sample in ethanol is read on a spectrophotometer at 230 mµ with the slit width maintained constant. The concentration is determined from a calibration curve relating absorbance to concentration. Absorption spectra of the purified ortho, meta, and para isomers have no peaks, but at constant slit width their absorbances at 230 mµ, obey Beer’s Law. Insufficient differences in the spectra of the three isomers precluded a satisfactory mathematical determination of the individual isomers.

The fluctuation of the flowing-out quantity of granules from the flat-bottomed hopper was investigated. Results are as follows;(i) The model hopper are made to continuing its vibration by the momentum change caused by the flowout of granules, because the hopper used is supported by two canti-levers (whose other ends are fixed) at its side walls.(ii) For the measured signals (that seems to be a kind of random waves), mainly, statistical analysis was performed for the discrete time series which are sliced from the alove random waves, and was drawn out the so-called ‘hidden-periodicity’ through the calculation of ‘autocorrelation coefficient’, ‘power-spectral density’ and ‘energy spectrum distribution’.(iii) The dominant periodical components or frequencies, thus obtained, vary with the width of the outlet at the underside of our model hopper. (First, the main frequency component increases slowly, then rapidly increasing as the width of the slit becomes larger.)(iv) These results (tendencies) are thought to correspond to the tendency exsisting between the slit width and the frequency of the arching action of granules occuring at the vicinity of the outlet of the hopper.