AN EXTENSION OF THE CHAPMAN-FERRARO THEORY OF GEOMAGNETIC STORMS

Extension of chapman-ferraro theory of geomagnetic storm

Short-lived Radio Bursts from the Crab Pulsar

Our high-time-resolution observations reveal that individual main pulses from the Crab pulsar contain one or more short-lived microbursts. Both the energy and duration of bursts measured above 1 GHz can vary dramatically in less than a millisecond. These fluctuations are too rapid to be caused by propagation through turbulence in the Crab Nebula or the interstellar medium; they must be intrinsic to the radio emission process in the pulsar. The mean duration of a burst varies with frequency as $\nu^{-2}$, significantly different from the broadening caused by interstellar scattering. We compare the properties of the bursts to some simple models of microstructure in the radio emission region.Comment: 34 pages, 10 figures; accepted for publication in Ap

NOTES ON MALAYSIAN CYPERACEAE

This is the first paper of a series, in which preparatory to a more comprehensive treatment for "Flora Malesiana," some noteworthy Malaysian Cyperaceae will be dealt with. It is based on the material of this family in the Herbaria at Bogor (BO), Leiden (L), and Singapore (S).My sincere thanks are extended to the Directors of these institutions for giving me the opportunity to study their rich collections.In 1935—36 Kiikenthal's excellent monograph on the genus Cyperus in Engler's "Pflanzenreich" appeared.Unfortunately that author revised only a few specimens of the herbaria already mentioned,so that the basis for the distribution of the genus in Malaysia, as given in his invaluable work, compares unfavourably with that of the species of other regions.Kiikenthal's delimitation of the genus is readily accepted; in general his arrangement of the species is also followed, although I cannot agree with Kiikenthal's assertion that his system should be in close accordance with the genetic development of the genus.On the whole only the synonymy important for the Malaysian region is given below. For a more complete account the reader is referred to Kiikenthal's monograph, in which of course the literature of merely regional interest could not always be fully considered.The accompanying plates are part of a series, drawn under mysupervision by two of the draughtsmen of Herbarium Bogoriense, Sukirno and Md. Anwar

A NEGLECTED INDIAN SPECIES OF CYPERUS

Cyperus iria var. rectangularis Ktikenth. in Engl., Pflanzenr., Heft 101: 152.1935. — Lectotypus: Duthie 23284 (Herb. Kew.).Cyperus iria (non L.) sensu Clarke, Illustr. Cyper. pi. H f. 1. 1909, non al. Duthie 4480. Subgen. Cyperus; sect. Iriae Kunth. — Annuus. Culmi erecti, tenues,triquetri, laeves, 1—7 dm alti, 1—2 mm crassi, inferne paucifoliati.Folia culmo breviora vel aequilonga, plana, flaccida, longe acuminata, in supe riore parte scabra, 1—5 mm lata. Anthela simplex vel subcomposita, laxa.Bracteae oblique patentes, 2—4 longissimae, foliis consimiles, anthelam valde superantes. Anthelae radii 3—9, e cladoprophyllis tubulosis ore oblique truncatis postice cuspidatis vel bidentatis basi bruneis 0.5—1.5 cm longis emergentes, inaequales, oblique patentes, graciles,compressi,laeves vel apice hispiduli, ad 16 cm longi,longiores nonnunquam apice pauci ramosi;radioli brevissimi ab ochreolo caudato suffulti. Spicae ovatae vel oblonga-ovatae, laxae vel subdensae, 1—3 cm longae, 8—25(—30) mm latae,5—20-spiculosae, rhachi flexuosa angulis hispida.Spiculae compressae,rectangule divaricatae vel imae subreflexae, ovatae usque ad oblongo-lineares, 3—12 mm longae, 2—2.5 mm latae, 4—18-f lorae, basi saepe a seta subuliformi suffultae. Rhachilla obscure brunea, recta, subexalata, internodiis 0.6—1 mm longis. Glumae membranaceae,1/3—1/2 parte imbricatae, patulae,concavae, fere orbiculatae, (1.75—)2mm longae ac latae, sub apice emarginato mucronulatae, dorso viridi 7-nerviae, lateribus fulvae purpureo notatae uninerviae, carina acuta arcuata superne angustissime alata,spinuloso-ciliata. Stamina 2; antherae breves, oblongae, interdum lineares; connectivum in appendicem brevem productum. Stylus fere nullus;stigmata 3, achenio multo breviora. Achenium ambitu obovatum, triquetrum, lateribus concavis, basi late stipitatum, apice mucronatum, atrobruneum, nitidum, dense puncticulatum, 1.5 mm longum, 0.8—0.9 mm latum

THE GENUS VIBURNUM (CAPRIFOLIACEAE) IN MALAYSIA

1. In the following pages an account of the genus Viburnum in Malaysia is presented.2. The distribution of its species is briefly discussed and a map relating to it added.3. The main part of the present paper consists of keys to the sections and species, followed by a systematic treatment of the 16 species admitted for the region.4. Three new subsections are proposed, viz. Viburnum subsect. Punctata Kern,subsect. Sambucina Kern, and subsect. Lutescentia Kern. Viburnum subseries Coriacea Maxim, is reduced to the rank of a subsection. 5. Three species and two varieties are described as new, viz. Viburnum amplificatum Kern, V. clemensae Kern, V. hispidulum Kern, V. coriaceum, var. longiflorutn Kern, and V. sambucinum var. subglabrum Kern. 6. The following species are reduced to the rank of varieties: Viburnum floribundum Merr. has become V. luzonicum var. floribundum (Merr.) Kern, and V. sinuatum Merr. has become V. luzonicum var. sinuatum (Merr.) Kern. 7. The following reductions'to synonymy are made: Viburnum longistamineum Ridl. to V. sambucinum- var. subglabrum Kern; V. sumatranum Miq., V.villosum Ridl., and V. inopinatum Craib all to V. sambucinum var. tovientosum Hallier f.;V. forbesii Fawc. partly to V. sambucimim Bl., partly to V. coriaceum BL; and V. zippelii Miq. to V. japonicum (Thunb.) Spr.8. Emended descriptions of Viburnum beccarii Gamble and of V. junghuhnii Miq. are given

AN ADDITIONAL NOTE ON VIBURNUM CLEMENSAE KERN

In "Reinwardtia" (1: 157. 1951) I published a new species of Viburnum from Mount Kinabalu, Borneo, under the name of V. clemensae.The description was drawn up after fruiting specimens in the Herbarium of the Arnold Arboretum. Unfortunately flowers were wanting in the specimens available.Some time ago Dr. A. J. G. H. Kostermans came across much more complete material among the indeterminata of the Bogor Herbarium, profusely flowering as well as fruiting. This enables the amplification of the description

FLORAE MALESIANAE PRAECURSORES XIII*Notes on Malaysian and some S. E. Asian Cyperaeeae IV*

The difficulties encountered in this group could not be solved by the application of this key to the numerous specimens I could study. In the type specimen of Scirpus pakapakensis Stapf from Borneo, Mt. Kinabalu, the stems are not trigonous. Although in Thwaites CP306 (type collection of Scirpus subcapitatus) the mucros of the leaf-sheaths and of the outermost glume are practically smooth, they are scaberulous in several Indian specimens otherwise quite agreeing with the type collection. In some specimens from Mt. Kinabalu the stems are slightly scaberulous at the top; for the rest they agree very well with the type of Scirpus clarkei Stapf

Bat Exclusion Methods

This publication is intended to serve as a review of currently accepted methods of bat exclusion. Inappropriate house bat control methods are destructive to our decreasing bat populations and often cause additional problems for the building\u27s owner or occupant. These problems include odor from dead bats, infestations of carrion-feeding flies, and increasing human and pet exposure to bats. Appropriate exclusion methods like winter structure modification for cave hibernating bats or one-way excluders using hardware cloth, plastic sheeting, or plastic birdnetting are the best ways to protect these beneficial wildlife species and correct situations where humans and bats come into conflict

Ag-coverage-dependent symmetry of the electronic states of the Pt(111)-Ag-Bi interface: The ARPES view of a structural transition

We studied by angle-resolved photoelectron spectroscopy the strain-related structural transition from a pseudomorphic monolayer (ML) to a striped incommensurate phase in an Ag thin film grown on Pt(111). We exploited the surfactant properties of Bi to grow ordered Pt(111)-xMLAg-Bi trilayers with 0 < x < 5 ML, and monitored the dispersion of the Bi-derived interface states to probe the structure of the underlying Ag film. We find that their symmetry changes from threefold to sixfold and back to threefold in the Ag coverage range studied. Together with previous scanning tunneling microscopy and photoelectron diffraction data, these results provide a consistent microscopic description of the coverage-dependent structural transition.Comment: 10 pages, 9 figure

Culvert hydrodynamics to enhance upstream fish passage: fish response to turbulence

Waterway culverts are very common structures along water systems, ranging from rural roads to national highways and urban drainage networks. Current design guidelines are inadequate for fish passage, especially small-bodied Australian native fish species. Physical modelling was conducted in the laboratory under controlled flow conditions with the aim to maximise slow flow and recirculation regions suitable to upstream passage of small fish. An asymmetrical boundary roughness configuration was tested, consisting of a rough invert and rough sidewall, and the results were compared to a smooth boundary configuration. The hydrodynamic measurements showed the marked effect of boundary roughness on the distributions of time-averaged velocity and velocity fluctuations. Experiments were also conducted on two small fish species (Silver perch, Duboulay's Rainbowfish). This roughness configuration appeared to provide secondary current regions next to the rough sidewall and at the corner between the rough sidewall and channel bed