1,598 research outputs found
A note on the Bryophytes of the Maltese Islands
No full textA small set of bryophytes collected on the islands of Malta and Gozo in April-May, 1968, and April, 1969, by K. U. Kramer and L. Y. Th. Westra (Utrecht) was handed to the author for identification. The results are presented here as a supplement to a paper on the vascular plants of the Maltese islands (Kramer et al. 1972). The collections are deposited in the herbarium of the State University of Utrecht.
In the past few years many new data have been published on the bryophytes of the Mediterranean islands, cf. Sunding (1967,1971), Koppe (1965), Lübenau & Lübenau (1970), Düll (1967), Gradstein (1971), and Townsend (1965). The liverwort flora of the Mediterranean coasts is being studied thoroughly by Jovet-Ast & Bischler (cf. 1968). Yet the bryophyte flora of the Maltese islands received very little attention in the literature. A brief survey of the main data follows here
A new Carex from Crete
No full textRhizoma caespitosum. Culmus erectus, triqueter, laevis, inferne foliatus, 15-30 cm altus. Folia culmo multo breviora, viridia vel cinereo-viridia, 1½-2½ mm lata, breviter acuminata, apice scaberula vel sublaevia, vaginis brunnescentibus; ligulae latiores quam longiores, obtusae vel subacutae. Bracteae foliaceae, inflorescentia breviores longioresve, superiores baud vel breviter vaginatae, inferiores vagina usque ad 1½ cm longa instructae; vaginae antice appendicula membranacea in sicco facile destructa provisae. Spiculae 3-4, terminalis ♂, cylindrica, 1½ cm longa, 2 mm lata, laterales ♀, in superiore parte culmi dispositae, oblongo-cylindricae, usque ad 1½ cm longae, 3-4 mm latae, densiflorae, suprema sessilis, inferiores subsessiles vel breviter pedunculatae, erectae, pedunculis laevibus usque ad ½ cm longis. Glumae ♂ obovato-lanceolatae, obtusae vel subacutae, glumae ♀ ovatae, acutae vel breviter acuminatae, muticae, tenuiter membranaceae, in carina viridi trinerves, marginibus enerviis albohyalinis demum brunnescentibus. Utriculi glumas superantes, oblique erecti, obovati, obtuse trigoni, basi subcontracti, cum rostro 2½-3 mm longi, 1 mm lati, praeter nervos 2 marginales prominentes enervosi, virides vel maturitate brunnescentes, vix nitidi, apice in rostrum usque ad 1 mm longum marginibus parce scabrum vel laeve ore breviter bidentatum abrupte contracti, crura intus scabriuscula. Nux utriculum explens, obovato-oblonga, trigona, 1½ mm longa, 1 mm lata, vix rostrata. Stigmata 3.
Crete, Nómos Chaniá: Distr. Kydónia, valley between Skinés and Néa Roúmata, on the bank of a brook in the maquis together with Carex remota, alt. 350 m, 6/5/1967, Gradstein & Smittenberg 304 (HOLOTYPE, U); id., on the bank of a brook in the “phrygana”, alt. 250 m, 5/5/1967, Gradstein & Smittenberg 277 (U, L, G); distr. Kíssamos, near Katsimatádos, schist-mountains, on the bank of a brook in the maquis, alt. 300 m, 17/4/1967, Gradstein & Smittenberg 148 (U, L)
S.R. Lewis letter to Z. Eastman, March 5, 1874
No full textBrief letter from S.R. Lewis to Z. Eastman, marking the announcement of an abolitionists' reunion to be held in Chicago in June of 1875. Lewis requests that Eastman, given his close acquaintance with Benjamin Lundy, prepare a public statement of remembrance on Lundy and his contributions to the anti-slavery movement. Benjamin Lundy (1789-1839) was a prominent Quaker abolitionist best known for his development of abolitionist periodicals. His Genius of Universal Emancipation was first published in 1821 from his home in Mt. Pleasant, Ohio, and enjoyed a wide circulation across the antebellum United States. In the 1820s, the young William Lloyd Garrison came to work for The Genius. Benjamin Lundy traveled widely seeking subscriptions to The Genius, giving talks about the anti-slavery movement, and observing and documenting the conditions of enslaved people across the Americas. He was also involved in the establishment of freed slave colonies in Mexico
Oil bodies in liverworts (Hepaticae)
No full textA characteristic feature of the liverwort cell is the presence of “oil bodies”. Chemically they are made up of rather volatile terpenoids, mainly sesquiterpenes and their derivatives (Suire 1975) which seem to be surrounded by a membrane. The nature of this membrane is still unknown.
Through the light microscope the oil bodies appear as colourless, rarely brownish or blueish organelles in the cytoplasm, showing great variation in shape, size, number and structure. The morphological characteristics of the oil bodies, which have been studied over 80% of the genera of Hepaticae, have been shown to be taxonomically significant (cf. Schuster 1966). While in the subclass Marchantiidae they are restricted to special, chloroplast-free “oil cells” of the gametophyte, in the remaining groups (subclass Jungermanniidae) they are abundant in the green cells of gametophyte and sporophyte. In the course of our investigations on tropical American liverworts we recognized four morphological types (Gradstein et al. 1977): 1) Massula type – oil bodies homogeneous, small (2-6 μm) and numerous, in median leaf cells more than 8 per cell. 2) Bazzania type – oil bodies homogeneous, large (4-15 μn long) and few, up to 8 per cell. 3) Jungermannia type – oil bodies finely segmented, consisting of numerous minute, indistinct globules surrounded by a common membrane. Size and number variable. 4) Calypogeia type-oil bodies coarsely segmented, consisting of distinct globules aggregated to form a “grape-cluster”; a common membrane seemingly lacking. Size and number variable
Modelling and optimization of a permanent-magnet machine in a flywheel
No full textThis thesis describes the derivation of an analytical model for the design and optimization of a permanent-magnet machine for use in an energy storage flywheel. A prototype of this flywheel is to be used as the peak-power unit in a hybrid electric city bus. The thesis starts by showing the feasibility of using a flywheel energy storage system for this application, as opposed to other energy storage technologies. It then continues by describing a prototype flywheel system and the required electrical machine: a radial-flux external-rotor permanent-magnet synchronous machine without slots in the stator iron and with a shielding cylinder. An analytical model for the machine is derived, based on 2D electromagnetic field calculations, including the reaction field of the eddy currents in the shielding cylinder. Torque and losses are calculated by means of the Theorem of Poynting and the Lorentz force. Such a machine was built and the analytical model has been validated by experimental measurements. Lastly, the thesis suggests and implements a machine optimization algorithm.Information Technology and System
Studies on Colombian cryptogams. IIB. Hepaticae – Oil body structure and ecological distribution of selected species of tropical Andean Jungermanniales
No full textOil bodies 7-12 in upper leaf cells, 10-20 in elongated basal leaf cells; globose to ellipsoid, 3-7(-10)x3-5 μm; colourless, coarsely segmented, consisting of c. 15-30 aggregated droplets (Colombia, Boyacá, páramos NW of Belén, Cabeceras Q. El Toral, 3765 m, Cleef 2292e; Ecuador, páramos de El Angel, 17 km. S. of Tulcán, 3350 m, Gradstein, Lanier & Weber s.n.).
The presence of segmented oil bodies in Colura patagonica is remarkable because previous studies of living Colura (from Japan) reported homogeneous oil bodies (cf. Schuster & Hattori 1964; Inoue 1974)
Design metrics for evaluating the propulsive efficiency of future ships
No full textThere is an increasing need for the ship design process to take account of environmental issues such as the emission of greenhouse gases and the likely extension of a carbon dioxide charging mechanism to international shipping. These issues, together with the need for economic viability, provide further incentives to improve the efficiency of propulsion of ships. The main components of powering are firstly reviewed. Individual components and other power saving devices are identified which should contribute to improvements in the overall efficiency of propulsion. Suitable design metrics and procedures, taking into account economic and environmental factors, are recommended for the design of future ships
Results of a botanical expedition to mount Roraima, Guyana. I. Bryophytes
No full textA bryological inventory of the Upper Mazaruni District, Guyana (former British Guiana) yielded almost three hundred species, including 2 genera and 11 species new to science and 130 species new to the Guianas. The densely forested and very humid north slope of Mount Roraima (500-2300 m.) proved to be the richest area for bryophytes and most of the novelties were found there. The present paper provides an enumeration of the species collected with a brief characterization of their habitat. The following species are described as new: Haesselia acuminata Gradst., Plagiochila gymnocalyx Inoue, Radula gradsteinii Yamada, Radula guyanensis Yamada, Radula mazarunensis Yamada and Stenorrhipis grollei Gradst. Anastrophyllum subg. Vanaea Inoue & Gradst. from Mount Roraima is elevated to generic rank
Description of S.R. Krom's system and machinery for dry crushing and concentrating ores.
No full textCover title.Mode of access: Internet.MAIN; TN500.K7 1876: Introduction signed by author, S.R. Krom
New or otherwise interesting Bryophytes from Crete
No full textThis report deals with the results of the determination of bryophytes collected by the author in 1967 in the western District of Chanià on the island of Crete. 33 species new to Crete were discovered and a number of bryophytes were collected for the first time in the District Chanià. Some species listed here were previously known from only very few European localities: Riella notarisii, Solenostoma handelii, Rhamphidium rechingeri and Trematodon longicollis. Rhamphidium rechingeri has been found to be conspecific with the west-mediterranean Rhamphidium purpuratum Michx. A few remarks are made on the distribution of the bryophytes on the island. A relatively rich flora of liverworts is present in District Chanià, which is due to a high annual precipitation-rate and to the presence of well-irrigated schistose mountain-areas in this region
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