bluuebunny/crossref_metadata_2025 huggingface dataset:
Nanoclusters of Dicyanocuprate(I) Anions in Aqueous Solutions: Investigating Cuprophilic Interactions
Authors: Nicholas Aaron D. , Connolly Roger P. , Szewczyk Thomas E. , Patterson Howard H.
Published: June 2019

The oligomerization of cyanocuprate(I) ions in aqueous solutions lacking and containing alkali cyanide salts (NaCN/KCN) has been investigated by infrared, Raman, and low temperature luminescence spectroscopy. In solution metallophilic interactions between Cu(I) metal centers bind the ions together into ∼1D chains. The structure and luminescence assignment of these nanoclusters was determined using simple Group Theory and Density Functional Theory calculations. Measurements show that the presence of KCN and NaCN in solution drives oligomerization of CuCN2− ions to higher order nanoclusters. Calculations of dimer and trimer clusters with K+ and Na+ ions indicate that alkali metals favor the formation of linear clusters as opposed to those that are bent. These findings fill an important gap in the understanding of d10 cyanometallate oligomers given the prevalence of cyanocuprate(I) in metal‐organic frameworks.
Bottlenecks, cooperation, and competition in nascent ecosystems
Authors: Hannah Douglas P. , Eisenhardt Kathleen M.
Published: June 2019

Douglas P. Hannah and Kathleen M. Eisenhardt were recognized as a runner up for the 2019 Ralph Gomory Best Industry Studies Paper Award.
Molecularly Designed Zinc (II) Phthalocyanine Derivative as Dopant‐Free Hole‐Transporting Material of Planar Perovskite Solar Cell with Preferential Face‐on Orientation
Authors: Hu Qikun , Rezaee Ehsan , Dong Lei , Dong Qingshun , Shan Haiquan , Chen Qian , Li Minzhang , Cai Siyuan , Wang Liduo , Xu Zong-Xiang
Published: June 2019

Efficient and stable hole‐transporting materials (HTMs) are necessary for perovskite solar cells (PSCs) with excellent efficiency and long‐term stability. Here, two A3B‐type metal phthalocyanine (MPc) compounds are prepared as dopant‐free HTMs for conventional n‐i‐p structured PSCs. Mono‐n‐butyl‐substituted zinc phthalocyanine and hexamethyl‐mono‐n‐butyl‐substituted zinc phthalocyanine (Me6Bu‐ZnPc) are synthesized through ring‐expansion method, and their exact structures are characterized using nuclear magnetic resonance and mass spectroscopy. The molecular orientation of the developed HTM thin films against the underlying surface is studied using X‐ray diffraction. Different substituents in MPcs can strongly affect their molecular orientation, resulting in different hole mobilities. The favored face‐on molecular alignment is only observed for Me6Bu‐ZnPc on the perovskite layer, proving the crucial role of methyl substituents in controlling the molecular alignment through the special interactions between the MPc molecule and different sites of perovskite material on the surface. PSCs using Me6Bu‐ZnPc as a dopant‐free HTM yields the highest reported power‐conversion efficiency (PCE) of 17.41%. With its high hydrophobicity and good coverage, Me6Bu‐ZnPc HTM thin film acts as an encapsulation layer, which leads to significantly increased long‐term stability. The Me6Bu‐ZnPc‐based devices retain over 90% of their initial PCE after 1400 h storage at 25 °C and with a relative humidity of 75%.
Development of a new solvent‐assisted dispersive solid‐phase extraction followed by ion mobility spectrometry for trace determination of organophosphorus pesticides in environmental water samples
Authors: Aladaghlo Zolfaghar , Fakhari Ali Reza
Published: June 2019

In this research, an effective sample preparation method called solvent‐assisted dispersive solid‐phase extraction followed by corona discharge ion mobility spectrometry was proposed for the trace determination of organophosphorus pesticides in environmental water samples. In this method, to maximize the interaction surface between target analytes and sorbent, the sorbent was dispersed into the aqueous sample. In this technique, the sorbent was dispersed at very low levels using a solution of sorbent and disperser solvent into the aqueous sample. Then, a cloudy solution was created by dispersing the sorbent particles in aqueous solution. After the interaction of organophosphorus pesticides and benzil, the cloudy solution was centrifuged and organophosphorus pesticides in the solid phase were dissolved in ethanol. In order to obtain the best extraction efficiency, the optimization of parameters affecting this method was examined. After optimization, the results were obtained as follows: pH of solution: 7.0, sorbent: benzil, 2% w/v, disperser solvent: ethanol, 500 µL, and centrifuge: centrifuged at 6000 rpm for 2 min. The presented method showed low method detection limit (0.3 ng mL−1), excellent preconcentration factor (368–376), good linearity (>0.994), repeatability (RSD < 4.1%), and high recoveries (92–94%).
A novel adaptive LFC based on MPC method
Authors: Rehiara Adelhard Beni , Yorino Naoto , Sasaki Yutaka , Zoka Yoshifumi
Published: June 2019

This article presents a novel load frequency control (LFC) method using an adaptive internal model of a power system, where model predictive control (MPC) technique is applied to the internal model, which is being updated on‐line. The proposed method will improve the LFC performance by reducing model identification error and by handling the disturbance effectively. Novelty lies in the combination of MPC and the effective use of the internal model to meet the response time of real world LFC control, which is typically equivalent to generation dispatch control cycle. The effectiveness of the proposed control is confirmed by simulations using a three‐area power system model. The results show that the proposed method can accurately identify the target plant and successfully handle disturbances to realize a reliable LFC. © 2019 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Localization of flow structures using -norm optimization
Authors: Foures D. P. G. , Caulfield C. P. , Schmid P. J.
Published: June 2019

Stability theory based on a variational principle and finite-time direct-adjoint optimization commonly relies on the kinetic perturbation energy density ${E}_{1} (t)= (1/ {V}_{\Omega } )\int \nolimits _{\Omega } e(\boldsymbol{x}, t)\hspace{0.167em} \mathrm{d} \Omega $ (where $e(\boldsymbol{x}, t)= \vert \boldsymbol{u}{\vert }^{2} / 2$) as a measure of disturbance size. This type of optimization typically yields optimal perturbations that are global in the fluid domain $\Omega $ of volume ${V}_{\Omega } $. This paper explores the use of $p$-norms in determining optimal perturbations for ‘energy’ growth over prescribed time intervals of length $T$. For $p= 1$ the traditional energy-based stability analysis is recovered, while for large $p\gg 1$, localization of the optimal perturbations is observed which identifies confined regions, or ‘hotspots’, in the domain where significant energy growth can be expected. In addition, the $p$-norm optimization yields insight into the role and significance of various regions of the flow regarding the overall energy dynamics. As a canonical example, we choose to solve the $\infty $-norm optimal perturbation problem for the simple case of two-dimensional channel flow. For such a configuration, several solutions branches emerge, each of them identifying a different energy production zone in the flow: either the centre or the walls of the domain. We study several scenarios (involving centre or wall perturbations) leading to localized energy production for different optimization time intervals. Our investigation reveals that even for this simple two-dimensional channel flow, the mechanism for the production of a highly energetic and localized perturbation is not unique in time. We show that wall perturbations are optimal (with respect to the $\infty $-norm) for relatively short and long times, while the centre perturbations are preferred for very short and intermediate times. The developed $p$-norm framework is intended to facilitate worst-case analysis of shear flows and to identify localized regions supporting dominant energy growth.
Slow Law: Temporal Logics in US Death Penalty Mitigation Investigations
Authors: Cheng Jesse
Published: June 2019

From arrest to sentencing, cases in which the defendant is charged with capital murder in the United States take substantially longer to resolve than homicide cases in which prosecutors choose not to seek the death penalty. One might reasonably attribute the slowness of capital trials to heightened procedural safeguards that attend the potential deprivation of life. In this article, I suggest that this explanation, straightforward as it is, glosses over more probing and analytically interesting truths about the complex temporal dimensions of death penalty trials. Based on my experiences as both a former defense advocate and an ethnographic researcher of capital defense practices, the slowness of capital cases revolves in large measure around the investigative pursuits of sentencing mitigation. Mitigation investigation’s knowledge practices are informed by distinct temporal operations whose interrelations feed into a deeper logic to capital defense advocacy. This article parses out and traces the connections between these inner workings, using social theory on time to articulate the processes by which mitigation’s temporal logics produce the characteristically slow pace of death penalty cases. I conclude with brief thoughts speculating how the temporal analysis experimented with here might be extended to processes of US criminal adjudication more broadly.
Locating parameters of interest in a conic section
Authors: Mahony John D.
Published: June 2019

In an interesting Note [1] a method for constructing the directrices of a conic section using simple tools, viz. a pencil, a pair of compasses and a straight edge, was presented and it was wondered if the method might have been known before. From earlier days at school this author was aware that for a specific conic section (parabola, ellipse or hyperbola) displayed without reference on a piece of paper it was possible to determine not just the directrices but also the focal points and the usual axis set, again using just the simple tools. Others might also be aware of these facts, but if they are not so well known it might be of interest to present an argument in recipe format that will enable readers to appreciate a route to fathom the business, although there might well be other paths leading also to the same end-result, depending on the starting point.
Latin square matrices and their inverses
Authors: McLean K. Robin
Published: June 2019

Magic squares have long been popular in recreational mathematics. Their potential for introducing students to ideas in linear algebra was recognised over forty years ago in [1] and later in [2]. More recently they have proved to be a fascinating topic for undergraduate exploration, especially when students have access to a computer algebra package [3]. Some results on powers of magic square matrices can be found in [4], [5] and [6]. (Readers who google the title ‘Odd magic powers’ of Thompson’s paper [5] will be treated to a wide variety of non-mathematical exotica!)
Launching a projectile to cover maximal area
Authors: Kantrowitz Robert , Neumann Michael M.
Published: June 2019

The launch and subsequent motion of a projectile provide a context for several quantities that yearn to be optimised. Most notable is the horizontal range of the projectile, a problem dating back to Galileo and still studied in modern times; see, for example [1], [2], [3], [4]. In a different direction, the articles [5] and [6] provide a solution to the problem of finding the angle of launch that results in the trajectory of longest arc length.
Evidence of Field Twisting in Integrated Profiles Observed Over a Wide Frequency Range
Authors: Izvekova V. A. , Kuz'min A. D. , Lyne A. G. , Shitov Yu. P. , Graham-Smith F.
Published: June 2019

The evolution of integrated pulse profiles from high to low frequencies does not conform exactly to the simple model of a dipole field. Several groups (DavÃ®es et al. 1984, Kuz'min 1986, Shitov, Malofeev, and Izvekova 1988) have suggested large field twisting due to the rotation of the pulsar, which leads to a delay in pulse arrival times for low frequencies whose sources are located in the outer parts of the magnetosphere. We are, therefore, comparing profiles of about 30 pulsars, observed at frequencies from 40 to 1400 MHz. Our preliminary analysis shows that significant delay at low frequencies occurs in many pulsars and we present here some typical examples.
Meridional Compression of Radio Pulsar Beams
Authors: Biggs James D.
Published: June 2019

We have studied the radio pulsar emission beam assuming a) a magnetic dipole field geometry and b) that the beam geometry is defined by the field lines that are not contained within the light cylinder. In general, the beam is compressed in the meridional direction. When the magnetic and rotation axes are aligned the beam is circular and as, the angle between these axes increases, the ratio of meridional to longitudinal dimension decreases monotonically to the minimum value 0.62 when the axes are orthogonal. This beam shape is thus consistent with that inferred from the study of circular polarization in average pulse profiles by Radhakrishnan and Rankin. Evidence for meridional compression is also found in the extensive observational study of Lyne and Manchester (1988).The beam evolution was determined using this data set, the beamwidth being found proportional to P–1/2, where P is the pulsar period. This relation implies that the more rapidly rotating pulsars should have larger beams, and this should aid in their detection. The more numerous, slower pulsars should have somewhat smaller beams than previously determined. This implies that the pulsar birthrate is probably close to the highest current estimates (1 in 25yr).
Some Aspects of Radio Pulsar Evolution
Authors: Beskin V. S. , Gurevich A. V. , Istomin Ya. N.
Published: June 2019

It is shown that pulsar statistics are in good agreement with the theory of current (plasma) energy losses of a neutron star. Up to now two theories of pulsar braking have been considered. The first well known model is connected with the radiation of vacuum magneto-dipole waves (Ostriker and Gunn 1969). However, according to the electrodynamical theory of pulsars, the presence of a rather dense plasma in the magnetosphere of a neutron star leads inevitably to a complete suppression of magneto-dipole losses—the dynamics of the stellar slow down is determined by the longitudinal current only (Beskin, Gurevich, and Istomin 1983).
The Vela Pulsar Glitch of Christmas 1988
Authors: McCulloch P. M. , Hamilton P. A.
Published: June 2019

We report the results of detailed observations of the Vela pulsar glitch which occurred on 24 December 1988. The period decrease occurred without warning and took place in much less than 2 minutes. The recovery, which commenced immediately, requires a complex function to model it, including three exponential terms and a damped sinusoid. An offset between data at two observing frequencies commenced at about the glitch epoch and continued for about 40 days; this is consistent with a small increase in dispersion measure or a change in the pulsar magnetic field configuration.
Results of Pulsar Timing Observations at 102.5 MHz
Authors: Shabanova T. V.
Published: June 2019

A program of pulse arrival time observations made at Pushchino during 1978-1986 is described. The period, period derivative and position derived from the full timing solutions were obtained for 16 pulsars. Comparison of our results with others obtained during 1970-1980 by different groups has shown that the parameters for a number of pulsars have suffered a significant change.
Pulsars, their Evolution, Winds and Radiation
Authors: Kundt W.
Published: June 2019

Controversial interpretations of the functioning and evolution of (radio) pulsars are discussed and confronted with the constraints. It is argued that (i) polarized e± bunches are ejected from near the polar caps at high Lorentz factors γ ≳ 102, that (ii) coherent radio pulses are emitted by them during transit to the outer magnetosphere via curvature radiation, (iii) in the shape of (transverse) fan beams, that (iv) there is no indication of magnetic field decay (or buildup), and that (v) pulsars die either by alignment or by interstellar quenching.

The so-called “millisecond” pulsars (outside globular clusters) are likely to be an abundant, young population of fast-born pulsars.
Particle Acceleration in Spherical Wave Fields
Authors: Thielheim K. O.
Published: June 2019

A magnet rotating in vacuo with its vector of angular velocity ω perpendicular to its vector of magnetic dipole moment μ is able to act as a particle accelerator. The dynamic features involved may be relevant for the understanding of rotating magnetized neutron stars as cosmic accelerators (Thielheim 1989) and may be useful for the designing of new mechanisms for accelerating devices.
On the Shape of the Pulsar Emission Diagram
Authors: Yusifov I. M.
Published: June 2019

On the basis of pulse profiles in a limited interval of wavelength for ~260 pulsars, the dependence of the shape and width of the pulsar radiation pattern on pulsar period is investigated. The relative pulse duration is compared with the ratio of numbers of single and multicomponent pulsars. It is shown that the simple circular hollow cone model does not agree with observational data. Preliminary estimates show that the young pulsars (with short periods) have an elliptical pattern which at long periods becomes circular.
Polarimetric Observations of 20 Weak Pulsars at 1720 Mhz
Authors: Xilouris Kiriaki M. , Rankin Joanna M. , Seiradakis John H. , Sieber Wolfgang
Published: June 2019

We present average polarization profiles for 20 pulsars at 1720 MHz made with the 100-m Effelsberg radio telescope. All four Stokes parameters were appropriately delayed in a linear dedisperser to correct the interstellar dispersion on-line. Our sample includes a number of complex profiles which were observed polarimetrically for the first time at a high frequency, with the aim of describing their frequency evolution. Classification of the corrected profiles is attempted according to the empirical pulsar model described earlier by Rankin(1990).
Pulsar Observations at Decameter Wavelengths using the Gauribidanur Telescope
Authors: Deshpande A. A. , Radhakrishnan V.
Published: June 2019

We report measurement of pulse profiles at 34.5 MHz of 8 pulsars using the Decameter-wave Radio Telescope at Gauribidanur, India. The dispersion measures of these pulsars range from 3 to 35 pc cm–3. None of the pulsars show any significant interpulse emission at this frequency which conflicts with earlier claims from 25-MHz observations (Bruck and Ustimenko 1976, Bruck and Ustimenko 1977a, Bruck and Ustimenko 1979). The intrinsic pulse width of PSR 1919+21 at 34.5 MHz appears to be smaller than at higher frequencies. These observations were made during the period 1984-86 and were reported by Deshpande (1987).
On the Primary Importance of Pulsars with Five-Component Profiles
Authors: Rankin Joanna M.
Published: June 2019

Some 15 members of the class of profiles with five components have been identified. These profiles have a central core component and two pairs of conal outriders, thus exhibiting the highest degree of formal complexity observed. No good examples of pulsars with six or more profile components are known.

Members of the five-component class have very similar physical parameters and emission-region geometries. An analysis of their emission geometry indicates both that the core and conal beams scale as P–1/2 and that the 1-GHz conal emission comes from a height of some 100-200 km.
Observations of the Millisecond Pulsar PSR 1855+09 At 102 MHz
Authors: Kuz'min A. D. , Alekseev Yu. I. , Lapaev K. A. , Losovsky B. Ya. , Salnikov A. A.
Published: June 2019

The study of millisecond pulsars is of great astrophysical interest. One may expect that the rotation effect on the structure of the magnetosphere should be very significant. In view of the short duration of the pulses they are very suitable for investigations of the interstellar medium; at least they hold the promise for the pulsar time scale.

Millisecond pulsars were discovered and have been studied on the basis of their radio-emission at decimeter wavelengths. At longer wavelengths scattering of the radio emission in the interstellar medium is the principal limitation of millisecond pulsar observations.
Profile Changes in the Binary Pulsar PSR 1913+16
Authors: Weisberg J. M. , Taylor J. H.
Published: June 2019

According to general relativity, the spin axis of binary pulsar PSR 1913+16 should precess at a rate of 1.21 degrees per year. This precession will cause the pulse profile to change as our line of sight samples different pulsar latitudes. In order to search for this phenomenon, we have carefully monitored the pulse profile at 1408 MHz for 8.5 years. The ratio of flux density of the first to second pulse component has declined at a rate of approximately 1.65% per year, with some evidence of a steeper decrease over the past three years. We have detected no evidence for a change in the separation of the two components. We discuss the nature of the pulsar emission region in light of these results.
The Maximum Moment of Inertia of Neutron Stars and its Implications for Pulsar Observations
Authors: Haensel Pawel
Published: June 2019

A simple approximate formula, expressing the maximum moment of inertia of a neutron star as a function of the mass and radius of the configuration with a maximum allowable mass, is shown to be a quite precise representation of the results obtained for a broad set of equations of state of dense matter. The resulting possible observational constraints in the mass-radius plane for neutron star models are discussed.
The Effect of Light Bending and Redshift on Pulsar Beaming: The Case of Shorter Rotation Periods
Authors: Kapoor R. C.
Published: June 2019

An estimate of the effect of light bending and redshift on pulsar beam characteristics has been made using a weak Kerr metric for the case of a 1.4 M⊙ neutron star with a radius in the range 6-10 km and rotation periods of 1.56 ms and 33 ms, respectively. Assuming that the pulsar emission has the form of a narrow conical beam directed away from the surface and is located within two stellar radii, the beam is found to be widened by a factor of ≤ 2 and to suffer a reduction in the intensity (flattening of the profile) by an order of magnitude or less. The effect is largest for the most rapidly rotating the neutron stars. For an emission region located beyond 20 km, the flattening is generally insignificant. The pulse profile is slightly asymmetrical due to dragging of the inertial frames. For millisecond periods, aberration tends to reverse the flattening effect of space-time curvature by narrowing the pulse and can completely overcome it for emission from a location beyond ≃30km. Although the pulse must slightly brighten up, a large redshift factor overcomes this effect to keep the pulse flattened for all neutron star radii considered here.
Pair-Production Avalanches Revisited
Authors: Michel F. Curtis
Published: June 2019

As noted previously in this meeting, any millisecond pulsar that is not perfectly aligned must obviously be strongly charged electrostatically simply because the wave zone is so close to the surface that any trapped neutralizing electrosphere over the polar caps will be driven away beyond 6 or 7 neutron-star radii. Acceleration of stray charges (e.g., from the ISM or a nearby orbiting disk) in such a highly charged system automatically produces coherently radiating bunches of downward moving particles (Michel 1990), this coherent radiation simply reflecting from the surface (or missing the star entirely, as an alternative possibility). This mechanism, suggestive of how pulsars might operate, we will call a pair-production avalanche.
Probing Magnetospheres of Rotation-Driven Neutron Stars
Authors: Cordes James M.
Published: June 2019

Magnetospheric issues are discussed as they relate to radio intensity variations, spindown, rotational noise, and emission altitudes. Radio fluctuations trace the overall state(s) of the magnetosphere in spite of the fact that Lradio ≪ IΩ. Five methods for estimating emission altitudes re are discussed. Four measure either the transverse width or radial depth of the emission region; assumption of a dipolar field and, in some cases, a radius to frequency mapping, yields estimates for the absolute radius of the emission region. The fifth method (v/c effects in Stokes parameter waveforms) provides direct altitude estimates. Most results suggest that re ≲ 0.02 RLC at v = 0.4 GHz. A radius to frequency mapping appears viable for some but not necessarily all objects. The mapping need not be one-to-one. Prospects are discussed for using simultaneous radio and high energy observations to make further progress in our understanding of magnetospheres.
On the Subpulse Drift in PSR 2303+30
Authors: Gil J. A. , Hankins T. H. , Nowakowski L.
Published: June 2019

We present an analysis of high signal-to-noise ratio, 430-MHz total intensity single pulse observations from PSR 2303+30 recorded at the Arecibo Observatory in August 1986. We believe that the regular subpulse modulation observed in this pulsar can be explained only in terras of subpulse-associated emission beams rotating around the axis of the pulsar beam. This idea was first introduced by Ruderman and Sutherland (1975) in their spark model. We use the quantitative prediction of this model to calculate the pulsar magnetic field. For this reason we need to estimate the rotation period of a spark around the magnetic pole. We estimate this period by reproducing the observed pulse sequences within an angular beaming model of subpulse emission and fitting this model to the data.
Causal Relationship between Drifting Subpulse Parameters and Some Pulsar Quantities
Authors: Shapirovskaya Natasha
Published: June 2019

Correlation analysis of subpulse spacing P2, subpulse bands P3, subpulse drift rate with some quantities such as pulsar period P, profile width We, characteristic age r and others indicates some new casual dependencies not previously confirmed. Relations obtained in this paper possibly point out that interaction between pulsar radio emission and the interstellar environment may exert some influence on the drift appearance.
A Model for the Drifting-Subpulse Phenomenon
Authors: Kazbegi A. Z. , Machabeli G. Z. , Melikidze G. I.
Published: June 2019

The subpulse drift phenomena—that is, periodic subpulse phase variations in the individual-pulse sequences—was discovered by Drake and Craft (1968) in the beginning of the pulsar era. Many observational programs have been carried out since then, and it has been shown a) that only a minority of pulsars exhibit the phenomenon, and b) that only some of these can be characterized by a definite drift rate (Huguenin, Taylor, and Troland 1970, Backer 1970, Taylor and Huguenin 1971).
Oscillations of Rotating Neutron Stars
Authors: Strohmayer T. E.
Published: June 2019

We use a perturbation technique to compute the rotational corrections to the non-radial oscillation spectrum of a realistic neutron-star model. We compute, to first order in the rotation rate, the corrections to the normal mode eigenfrequencies and eigenfunctions. We find that l = l0 oscillations are coupled to l = l0 ± 1 oscillations by the Coriolis force. For the toroidal modes, this coupling introduces a non-zero radial component to the velocity field. We have used this result to compute the neutrino damping rates for several corrected toroidal modes. This damping mechanism is inoperative for toroidal modes in a non-rotating star because these modes produce no density nor temperature perturbations. The neutrino damping time can approach the gravitational radiation damping time in rotating neutron stars if the central temperature is high enough, (Tc ≥ 108 K). The rotationally induced coupling of spheroidal oscillations to toroidal modes can also produce significant displacements at the stellar surface. This may have interesting implications for channeling energy, e.g., that associated with a glitch, to the surface of the star. Perhaps this might produce observable effects in the pulsar emission process or a γ-ray burst event.
A Non-Linear Emission Mechanism for Pulsar Radio Radiation
Authors: Asseo E. , Pelletier G. , Sol H.
Published: June 2019

Among the various plasma instabilities which could be responsible for coherent pulsar radio emission, we investigate the two-stream instability, first introduced by Ruderman and Sutherland (1975) in order to account for the physical situation expected in the environment of neutron stars. They describe how, in a polar cap model, pair creation arises and leads to the formation of a very energetic beam of e+ (and/or e−) and of an e−e+ plasma, both with relativistic bulk motion along the bundle of dipolar magnetic field lines. The study of their interaction is limited to the cone of open B lines, a site which provides a natural geometry for the radio emission zone, observed as core and/or conal emission by Lyne and Manchester (1988) and Rankin (1983, 1986, 1990).
The Phase Stability of Micropulses from PSR 1133+16
Authors: Pugachev V. D. , Shitov Yu. P. , Soin A. G.
Published: June 2019

As is very well known, there are two different kinds of time structure of the individual pulses of pulsars. There are microstructures with time scales less than 1 ms and subpulse structures, the usual scale of which is of the order of 10 ms. Subpulses are a result of the radiation beam rotation and in many cases demonstrate some regularity of arrival phases. In contrast, microstructure looks rather like a short pulse of noise with random phases of micropulse appearance in the radio emission window of the pulsar. Because the appearance phases of micropulses are random in the pulsar period, it is very difficult to establish what the fundamental character of these micropulses is: are they a temporal variation of radio emission intensity or the result of narrow beam rotation?
Observation of the Linear Polarization of Pulsar Integrated Pulses and Sub-Pulses at Meter Wavelengths
Authors: Suleymanova S. A. , Pugachev V. D.
Published: June 2019

A brief review of polarization observations at 103, 60, and 40 MHz is given. Our peculiar measurement technique allows us to obtain average polarization profiles as well as statistical distributions of the polarization parameters of individual pulses and subpulses. Some examples are given in this paper.
Radiation Damping and the Two Mode Behavior in Pulsars
Authors: Björnsson C. -I.
Published: June 2019

It is argued that both observations and theory indicate that radiation damping plays an important rôle in pulsar emission. The two-mode behavior as well as the observed value of the brightness temperature can both be understood as a result of radiation damping. In this context, a possible cause for the enhanced depolarization in the wings of pulsar profiles is discussed.
On Curved Barriers
Authors: Brodetsky S.
Published: June 2019

In two-dimensional discontinuous fluid motion one point of considerable importance has not hitherto been given sufficient attention. I raise it formally in a paper to be published soon (Fluid Motion past Circular Barriers, Scripta Universitatis atque Bibliothecae Heirosolymitanarum, 1923, Vol. I., XI., 1–14) in the following manner. Given the form of the barrier by means of, say, the radius of curvature in terms of the angle of contingence, how does the solution take into account the angular extent of the barrier? Clearly barriers which are defined by the same curve, but differ in the extent of curve used, must necessarily give rise to different solutions. Further, there must be a limiting extent of barrier, so that if it extends beyond this limit the part of the barrier in excess must lie in the “dead” fluid.
On a Linear Partial Differential Equation of Hyperbolic Type
Authors: Copson E. T.
Published: June 2019

Riemann's method of solution of a linear second order partial differential equation of hyperbolic type was introduced in his memoir on sound waves. It has been used by Darboux in discussing the equation

where α, β, γ are functions of x and y.
The Vibrations of a Particle about a Position of Equilibrium—Part III
Authors: Baker Bevan B.
Published: June 2019

In the two parts of this investigation previously published it has been shown that the solution in terms of elliptic functions represents the motion of the particular dynamical system under consideration throughout the whole range of values of s and g for which a real solution exists, except for those values for which s = 2g and k = 1, but that, on the other hand, the series solution is convergent and represents the motion only so long as

for values of s and g for which the sign of this inequality is reversed the trigonometric series representing the solution are divergent. It is of importance to investigate what discontinuities, if any, of the system correspond to values of s and g which lie on the boundary of the region of convergence; the present part is concerned primarily with showing that under such circumstances no discontinuity of the system exists, thus confirming the suggestions made in Part I., § 12.
The Vibration of a Particle about a Position of Equilibrium—Part IV
Authors: Baker Bevan B.
Published: June 2019

It has been shown in the previous three parts of this work, that the whole question of the convergence of the series solution, for the particular dynamical system under consideration, has turned upon the cubic equation

Before proceeding to generalize the results it will be shown how this cubic equation may be derived in a slightly different fashion.
Palaeomagnetic dating of hydrothermal alteration in the Woodford Shale, Oklahoma, USA
Authors: Roberts Jennifer , Heij Gerhard , Elmore R. Douglas
Published: June 2019

An oriented Woodford Shale core from the eastern Ardmore Basin was sampled to test if the shale was an open or closed system to hydrothermal fluids, and to determine the timing of alteration. Mineralized fractures are ubiquitous in the core, and the shale exhibits a complex paragenesis with multiple hydrothermal minerals, including biotite, magnesite, norsethite, gorceixite and potassium feldspar present in and around the fractures. These minerals suggest that the Woodford Shale was an open system during part of its diagenetic history. Vitrinite reflectance (Ro) measurements indicate values of ∼1.81 % (∼230 °C). Palaeomagnetic analysis reveals a characteristic remanent magnetization (ChRM) with south-southeasterly declinations and shallow inclinations that resides in magnetite. This ChRM is interpreted to be either a chemical remanent magnetization (CRM) or a thermochemical remanent magnetization (TCRM) that was acquired at 245 ± 10 Ma during Late Permian time based on the pole position (51.0° N, 115.6° E). Because the palaeomagnetic specimens show evidence of extensive hydrothermal alteration, the CRM/TCRM is interpreted to date the migration of hydrothermal fluids through the shale. The agreement in timing with other studies that report hydrothermal alteration in southern Oklahoma and the Ouachita Mountains in Late Permian time, suggest that there were post-collisional fluid-flow events which accessed reservoirs of warm fluids.
Siliceous-sulphate rock coatings at Zhenzhu Spring, Tengchong, China: the integrated product of acid-fog deposition, spring water capillary action, and dissolution
Authors: Wen Huaguo , Xu Wenli , Li Yi , You Yaxian , Luo Xiaotong
Published: June 2019

Siliceous-sulphate rock coatings were observed at Zhenzhu Spring, an acid sulphate hot spring in the Tengchong volcanic field, China. These rock coatings are mainly formed of gypsum and amorphous silica. Some alum-(K), voltaite, α-quartz and muscovite were also found. Four different laminae are developed in the rock coatings: gypsum layer, tight siliceous layer, tabular siliceous layer and siliceous debris layer. The gypsum layer is located at the top of the rock coatings, while other siliceous layers appear below the gypsum layer. Geochemical modelling of the fluids was performed to identify the mechanisms responsible for the formation of gypsum and amorphous silica. The results indicated that the occurrence of gypsum is related to the acid-fog deposition and amorphous silica mainly originates from spring water. Fog deposition provided the rock coatings with abundant SO42−and Ca, and the subsequent complete evaporation of the condensed fluids produced gypsum. Seasonal climate change (especially variation in rainfall) determines the fluctuations of capillary action and dissolution. Rainfall events in the wet season led to periods of non-precipitating gypsum and promoted the capillary rise of the spring water. Slightly diluted capillary water (a small amount of rainwater) covered the rock coatings, formed a tight siliceous layer on the rock-coating surface and/or filled the pores among the gypsum crystals forming many tabular siliceous aggregates. Heavy rainfall (high dilution), however, resulted in non-precipitating amorphous silica and accelerated the gypsum dissolution, leaving tabular pores around tabular siliceous aggregates and forming a tabular siliceous layer.
The Apollo Temple on Sikinos
Authors: Dawkins R. M.
Published: June 2019

Modern archaeological effort, in its zeal to exhibit every surviving vestige of antiquity, has removed from most ancient buildings all the accretions of later ages, and although much has been gained for our knowledge of their original condition quite as much has often been lost to our realisation of history. The buildings of the ancients, when no longer needed for their first purposes, were not always or even generally destroyed; they were adapted to the needs of the newer world, and of this process, by which the Parthenon became first a church and then a mosque, and the theatre of Marcellus at Rome is still an inhabited block of shops and dwellings, a small but interesting example is to be found on the island of Sikinos, where the temple of the Pythian Apollo, at some period converted into a church by the addition of the features necessary to the Greek rite, still remains in that condition as the church of the Episkope. It is, therefore, not the cleaned-up ruin to which our eyes have grown so accustomed, but an untouched historical document of the vicissitudes undergone by so many of the buildings of antiquity.
Prehistoric Remains in South-Western Asia Minor.—II
Authors: Ormerod H. A.
Published: June 2019

The village of Senirdje is situated some 15 km. to the N.N.W. of Isbarta (Baris), in northern Pisidia, in a gap in the hills dividing the plain of Isbarta from the plain of Ketchiborlu, through which the line of the railway-extension from Ketchiborlu to Egerdir now passes. Close to the village is a low, flat mound, in marshy ground, which, when I visited it in 1911, was entirely flooded owing to the severity of the previous winter. The mound, the northern part of which is traversed by the railway-cutting, rises to a height of 13 feet above the level of the plain, and 11 ft. 6 in. above the rail, at a point 150 feet to the right of the centre-line. The top of the northern bank of the cutting is about five feet above the rail, the southern bank about 9 feet. Some 18 inches down to the level of the plain remain unexcavated.
A Possible Egyptian Dating for the End of the Third Late Minoan Period
Authors: Peet T. E.
Published: June 2019

In the last number of the Zeitschrift für Aegyptische Sprache Max Burchardt publishes two swords lately acquired from Egypt by the Berlin Museum. The first (Inventory Number 20447), (Fig. 1), almost perfectly preserved, is a fine example of Naue's Type II. It is a cutting sword with edges almost parallel and the end bluntly pointed. The handle is made in one piece with the blade. Its edges are raised on either side and it is fitted with eight rivet holes. Down the blade, whose faces are slightly convex, run on either face four fine furrows parallel to the edges. The total length is 715 mm. The sword was found at Zagazig (Bubastis) in the Delta.

The second sword (Inventory Number 20305) is unfortunately badly damaged but probably belongs to the same type. It certainly has the same section and the same almost parallel edges. There is, too, the same thickening of the handle at the point where it joins the blade and the disposition of the rivets is similar in the case of such as remain. I have not yet had the opportunity of examining the original and so must be content with quoting Burchardt's opinion on this point.
I. The site and its environs
Authors: Cook J. M.
Published: June 2019

The site of Old Smyrna lies on a low spur at the foot of the Yamanlar Daği, or Mountain of Unco Things, at a distance of 450 metres east of the present coastline. The spur is 365 metres long on a north-south axis, with a maximum breadth of 250 metres. On the north-east and east its outline is marked by a bank, revetted in large part by a high terrace wall of small stones. The elevated north-west corner of the site is encircled by superimposed terraces leading up to a circular platform or belvedere, which dominates the site, at an altitude of 21·3 m. above sea-level (Plates 2c, 6a, Squares G–Hix). On the west side the spur is bounded by a cart road leading inland to Bornova, and at the south tip it merges into the low-lying pasturage by a sluggish stream. The terracing of the hillock, which in the north-west presents a picturesque aspect, is believed in the main to be the work of a landowner named Turlita in the nineteenth century. A zone along the north side of the site, corresponding in width to the main sector of our excavations there, is planted with olive trees, of which we were obliged to cut down a score; there is also a narrow fringe of olives along the eastern edge of the site. The greater part of the surface of the hillock is divided between two vineyards, the upper on the north and the lower on the south, separated by a bank which is bordered near its east end by a row of fig trees (Squares Nxvi to Gxix); there is also a smaller vineyard of triangular outline on the slope between the upper vineyard and the Bornova road.
The bronzes
Authors: Sandars Nancy
Published: June 2019

The Knives. Three complete one-edged knives, and one fragmentary, were found in the tombs. The bronze knive (I. 5) belongs to a small group in which the whole of the handle including a T-shaped pommel extension was cast in one piece with the blade, while inset panels of perishable material were secured by rivets and deep flanges in the metal. Apart from this pommel-flange it is similar to a large contemporary group of bronze knives to be found throughout the Aegean.

One-edged knives with flanged handles are at least as old as the Shaft-grave period at Mycenae. In Crete a riveted handle without flanges was preferred from Middle Minoan times, but the flanged handle appears at the end of Late Minoan II or the beginning of IIIA. The pommel-flange is rare, though found occasionally on both riveted and unriveted knives. The earliest dated example is probably that from the Palace of Mycenae found with other objects of Late Helladic II or early III date; one comes from Dendra, Chamber Tomb 7, and one unriveted from Chamber Tomb 2, dated L.H. IIIB. The Mycenae knife has not the true T-projection but only a broadening at the end of the handle which is in shape very like handles of Levantine daggers and two-edged knives found in the so-called ‘Hyksos tombs’ of Ras Shamra and at Tell el Ajjul, Tell Fara, and elsewhere in Palestine.
Excavations at Pindakas in Chios
Authors: Boardman John
Published: June 2019

Pindakas is a small and low hill lying about 1·5 km. from the harbour at Emporio in South Chios. It is at the foot of the hills which divide the modern town of Pyrgi from the Emporio valley, but it also commands access to the adjacent valley to the north, that leading to modern Kalamoti (see Figs, 1 and 2). The position is, however, one which is better called convenient than strategic. The name must derive from πίδαξ, ‘spring’ or ‘fountain’, and, although there is no water on the hill itself, an excellent well lies close to its slopes on the west. Ano- and Kato-Pindakas have been distinguished, but the distinction is lost today, and Ano-Pindakas, rather nearer Emporio, is as bare of human habitation as Kato-Pindakas, which is our site.

Today the flat top of the hill is bare and rocky with scattered olive trees, though the fields around are rich in corn and mastika. Zolotas had noted antiquities there but it is the great polygonal walls at the west which make two terraces of the hill-top that are the most conspicuous remains (Plate 72a–b). It was on these two terraces that excavations were conducted by the writer in July 1954, in the course of the British School at Athens' excavations at Emporio. Sections were cut east–west through the upper and lower terraces, and north–south through the upper terrace (Figs. 3 and 4, AA and BB) and these, with minor trenches and some ground observation, tell a clear story of the site's history and buildings.
Cannda’s Role in the International Commission for Supervision and Control in Laos
Authors: Dai Poeliu
Published: June 2019

Unlike the International Commissions for Supervision and Control in Vietnam and Cambodia which were established pursuant to the 1954 Geneva Accord, the International Commission for Laos was the product of two Geneva Conferences held in 1954 and 1962. The two Geneva Agreements on Laos envisaged the fulfilment of different political objectives. Whereas the 1954 Agreement was designed to reestablish the independence and integrity of Laos and to insure the withdrawal of the Viet Minh forces therefrom, the distinctive features of the 1962 Agreement included the legitimization of a Government of National Unity embracing all three Laotian factions, that is, the Royalists, the Leftists and the Neutralists, as well as an international recognition of the independence and neutrality of Laos.
Certificats présentés en cour par le Ministère des Affaires extérieures: La pratique canadienne
Authors: Hardy Vincent
Published: June 2019

J’ai eu l’occasion de consulter de façon exhaustive, au cours de l’été 1976 les dossiers du Ministère canadien des Affaires extérieures susceptibles de contenir des certificats destinés à être présentés en Gour. Je me propose de donner ici un bref résumé des principes qui en guident l’émission, ainsi qu’un aperçu de la forme qu’ils revêtent.

1. Les principes

Un certificat du Ministère des Affaires extérieures est un document émis par le Secrétaire d’Etat aux Affaires extérieures ou par un fonctionnaire du Ministère, établissant l’existence de certains faits et dans certains cas de certaines règles de droit qui y sont liées, dont le Ministère est susceptible d’avoir connaissance de par ses attributions. Normalement, la Cour ne mettra pas en doute le contenu du certificat, dont elle prendra connaissance judiciaire.
Deux récents accords bilatéraux en matière de pêche en 1977
Authors: de Mestral A. L. C.
Published: June 2019

Le 1er Janvier 1977 le Canada porta la limite de ses zones de pêche au large de la côte est et de la côte ouest à 200 milles marins de la côte. Une autre zone de pêche semblable fut créée deux mois plus tard au large de l’archipel arctique. Même si les intérêts de nombreux pays membres de la commission internationale des pêcheries de l’Atlantique du nord-ouest (C.I.P.A.N.) et de la commission des pêcheries du Pacifique du nord risquaient d’être sérieusement compromis, aucun état ne contesta cette décision du gouvernement canadien. Ceci résultait de plusieurs facteurs, entre autres les développements au sein de la troisième conférence des Nations Unies sur le droit de la mer et l’évolution des relations entre les 16 états membres de la C.I.P.A.N. Mais sur le plan pratique, le facteur principal, du moins à court terme, semble avoir été la signature par le Canada d’une série d’accords bilatéraux avec les principaux états membres de la C.I.P.A.N. Les aspects saillants de ces accords bilatéraux ont été décrits par l’auteur dans une note antérieure publiée dans cette revue.