1,935 research outputs found
SPATIAL DISTRIBUTION OF DICOTYLEDONOUS WEED ARCHITECTURES IN A SHRUB VEGETATION OF MENGGALA, CENTRAL JAVA
B. SUNARNO & F. HALLE. 1986. Distiibusi spasial model arsitektur gulma dikotil di daerah vegetasi semak, Menggala, Jawa Tengah. Berita Biologi 3(6): 253 - 260. Ketapatan dan frekuensi kehadiran model-model arsitektur gulma dikotil di daerah vegetasi semak Menggala, Jawa Tengah telah dipelajari.Model CHAMPAGNAT yang diwakili oleh Mimosa invisa dan Rubus chrysophyllus merupakan model yang nilai kerapatannya paling tinggi (17,97%) dan merupakan pola pertumbuhan yang umum dijumpai di setiap stratum.Semakin tinggi tingkat stratumnya semakin rendah jumlah model dan jumlah individunya. Perbandingan antara gulma masa mendatang dengan gulma masa kini di daerah semak ini, adalah 3 : 2, menunjukkan a,danya proses suksesi yang sedang berjala
ARCHITECTURE OF DICOTYLEDONOUS WEEDS IN SOME AREAS OF BANYUMAS REGENCY CENTRAL JAVA
B. SUNARNO & F. HALLE. 1986, Arsitektur jenis-jenis gulma dikotil di beberapa daerah Banyumas, Jawa Tengah. Bcriia Biologi 3(4): 146 - 154 Pengamatan lapangan dilakukan untuk mengetahui jenis-jenis gulma dikotil yang pola pertumbuhannya mirip dengan model arsitektur pohon.Hasilnya menunjukkan adanya 14 model pada 180 jenis gulma yang tumbuh di 4 daerah Kecamatandi Kabupaten Banyumas.Model yang paling umum dijumpai adalah model STONE, model LEETJWENBERG dan model ATTIMS.Suku yang dianggap kaya dengan model antara lain Euphorbiaceae (10 jenis).Lamiaceae (14 jenis), Papilionaceae (20 jenis) yang masing-masing memiliki 5 model dan Asteraceae (37 jenis) dengan 4 model.Marga polimorfik dijumpai pada Cassia, Desmodium, dan Lindernia yang masing-masing dengan 3 model dan pada Mimosa. Ocimum, Polygala serta Pluchea masing-masing memiliki 2 model.Dalam penelitian ini tidak diketemukan model arsitektur yang baru
Reaction of Cr+, Mn+, Fe+, Co+, and Ni+ with O2 and N2O. Examination of the translational energy dependence of the cross sections of endothermic reactions
Journal ArticleReactions of Cr+, Mn+, Fe+, Co+, and Ni+ with 02 and N20 to yield metal oxide ions are examined using an ion beam apparatus. Reaction cross sections a as a function of ion translational energy E are reported. With one exception, Fe+ + N20, the cross sections exhibit an energy threshold E0
Speech Analysis
Contains research objectives and reports on one research project.National Science Foundatio
On the run for water - Root growth of two phreatophytes in the Taklamakan Desert
Desert phreatophytes require extremely fast root growth for a successful establishment We measured the speed of seedling root growth of two phreatophytic plant species, Alhagi sparsifolia and Karelinia caspia, which form dominant or codominant stands around the river oases at the southern fringe of the Taklamakan Desert. As A sparsifolia occurs at sites with deeper groundwater, we expected the roots of this species to reach down more rapidly than those of K caspia. Furthermore, we expected seedlings experiencing no irrigation and low fertilization to have deeper reaching roots than seedlings with irrigation and fertilization. Seeds of both species were sown into 1 and 2 m long tubes in a glasshouse and in a field experiment, respectively. After 16 weeks of growth in the field roots of K. caspia and A. sparsifolia reached down 2 2 m and 1.7 m, respectively. In accordance with a faster growth, K. caspia had a higher water use, which resulted in a faster decrease of water content in the tubes. Species differences in the vertical reach of roots in the glasshouse experiment were comparable to those in the field experiment After 12 weeks without irrigation, A sparsifolia had a higher rooting depth (0.45 m) than with irrigation (0 30 m), while root depths of K caspia showed the opposite pattern with 062 m and 0 72 m, respectively Fertilizing increased total biomass of both species, while low level of fertilization had the tendency to increase the root shoot ratio and the specific root lengths (SRL), most likely a response to acquire nutrients at lower costs. However, plants of K. caspia showed an increase in SLR already after 12 weeks, while it took 16 weeks for A sparsifolia to increase SRL in the low fertilization level. Our results show clearly that both species are able to reach the groundwater table in the river valleys (6 5 m) within a time span of five to six months after germination However, the encountered vegetation pattern is probably not caused by differences in the speed of rooting depth, but might be the result of a higher capability of growing up with sand accumulation of A sparsifolia. As additional irrigation and fertilization did not enhance rooting depth in both species, these factors will have little impact in restoration procedures (C) 2010 Elsevier Ltd All rights reserve
Reaction of Cr + , Mn + , Fe + , Co + , and Ni + with O2 and N2O. Examination of the translational energy dependence of the cross sections of endothermic reactions
Reactions of Cr + , Mn + , Fe + , Co + , and Ni + with O2 and N2O to yield metal oxide ions are examined using an ion beam apparatus. Reaction cross sections sigma as a function of ion translational energy E are reported. With one exception, Fe + +N2O, the cross sections exhibit an energy threshold Eo. Several models are used to interpret the excitation functions for the O2 reactions and it is concluded that the classical line-of-centers form sigma alpha (1–Eo/E) is most useful. Bond energies derived in this manner are D°(CrO + ) = 3.45±0.1 eV, D°(MnO + ) = 2.48±0.1 eV, D°(FeO + ) = 3.01±0.1 eV, D°(CoO + ) = 2.76±0.1 eV, and D°(NiO + ) = 1.95±0.1 eV. Since these bond energies are all greater than D°(N2–O) = 1.7 eV, the observation of energy thresholds for the reactions with N2O are surprising. These results are explained in terms of a qualitative view of the electronic potential energy surfaces involved
Linguistics
Contains research objectives and reports on two research project.National Institute of Mental Health (Grant 5 P01 MH-13390-04
Realfast: Real-Time, Commensal Fast Transient Surveys with the Very Large Array
Radio interferometers have the ability to precisely localize and better
characterize the properties of sources. This ability is having a powerful
impact on the study of fast radio transients, where a few milliseconds of data
is enough to pinpoint a source at cosmological distances. However, recording
interferometric data at millisecond cadence produces a terabyte-per-hour data
stream that strains networks, computing systems, and archives. This challenge
mirrors that of other domains of science, where the science scope is limited by
the computational architecture as much as the physical processes at play. Here,
we present a solution to this problem in the context of radio transients:
realfast, a commensal, fast transient search system at the Jansky Very Large
Array. Realfast uses a novel architecture to distribute fast-sampled
interferometric data to a 32-node, 64-GPU cluster for real-time imaging and
transient detection. By detecting transients in situ, we can trigger the
recording of data for those rare, brief instants when the event occurs and
reduce the recorded data volume by a factor of 1000. This makes it possible to
commensally search a data stream that would otherwise be impossible to record.
This system will search for millisecond transients in more than 1000 hours of
data per year, potentially localizing several Fast Radio Bursts, pulsars, and
other sources of impulsive radio emission. We describe the science scope for
realfast, the system design, expected outcomes, and ways real-time analysis can
help in other fields of astrophysics.Comment: Accepted to ApJS Special Issue on Data; 11 pages, 4 figure
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