205 research outputs found
Pengaruh Pemupukan Nitrogen Dan Sistem Olah Tanah Jangka Panjang Terhadap Pertumbuhan Dan Produksi Padi Gogo (Oryza Sativa L.) Tahun Ke-27 Di Lahan Politeknik Negeri Lampung
Padi gogo merupakan salah satu tanaman pangan yang berpotensi untuk dikembangkan. Pada tahun-tahun mendatang peranan padi gogo dalam penyediaan beras nasional menjadi semakin penting. Hal ini disebabkan karena semakin berkurangnya areal persawahan, sedangkan tingkat pertumbuhan penduduk cukup tinggi. Salah satu upaya dalam meningkatkan pertumbuhan dan produksi padi gogo adalah dengan sistem olah tanah dan pemupukan nitrogen. Tujuan penelitian adalah untuk mengetahui pengaruh pemupukan nitrogen jangka panjang dengan berbagai dosis terhadap pertumbuhan dan produksi padi gogo, mengetahui pengaruh sistem olah tanah jangka panjang terhadap pertumbuhan dan produksi padi gogo, dan mengetahui pengaruh interaksi antara sistem olah tanah dan pemupukan nitrogen jangka panjang dengan berbagai dosis terhadap pertumbuhan dan produksi padi gogo. Penelitian dilakukan di lahan Politeknik Negeri Lampung. Analisis tanaman dilakukan di Laboratorium Ilmu Tanaman Jurusan Agroteknologi Fakultas Pertanian Universitas Lampung. Penelitian dilaksanakan pada bulan Oktober 2014 sampai dengan Maret 2015. Penelitian dilakukan menggunakan Rancangan Acak Kelompok (RAK) yang disusun secara faktorial dengan 4 ulangan. Hasil penelitian menunjukkan bahwa pemupukan nitrogen dengan dosis 100 kg N ha -1 meningkatkan pertumbuhan dibandingkan tanpa pemupukan nitrogen tetapi tidak berbeda dengan pemupukan 50 kg N ha -1 . Pemupukan nitrogen dengan dosis 100 kg N ha -1 meningkatkan produksi padi gogo lebih tinggi dibandingkan tanpa pemupukan nitrogen tetapi tidak berbeda dengan pemupukan 50 kg N ha -1 . Sistem Olah Tanah Intensif mampu meningkatkan tinggi tanaman, dan bobot kering berangkasan lebih tinggi dibandingkan dengan Olah Tanah Konservasi, sedangkan sistem olah tidak memberikan pengaruh terhadap komponen hasil. Interaksi antara pemupukkan nitrogen dan sistem olah tanah terjadi pada variabel pengamatan tinggi tanaman, sedangkan terhadap komponen hasil tidak berpengaruh
An all-solid-state laser source at 671 nm for cold atom experiments with lithium
We present an all solid-state narrow line-width laser source emitting
output power at delivered in a
diffraction-limited beam. The \linebreak source is based on a
fre-quency-doubled diode-end-linebreak pumped ring laser operating on the
transition in Nd:YVO. By using
periodically-poled po-tassium titanyl phosphate (ppKTP) in an external build-up
cavity, doubling efficiencies of up to 86% are obtained. Tunability of the
source over is accomplished. We demonstrate the suitability of
this robust frequency-stabilized light source for laser cooling of lithium
atoms. Finally a simplified design based on intra-cavity doubling is described
and first results are presented
Cardiovascular Response to Intraneural Right Vagus Nerve Stimulation in Adult Minipig.
Objective: This study explored intraneural stimulation of the right thoracic vagus nerve (VN) in sexually mature male minipigs to modulate safe heart rate and blood pressure response.
Material and methods: We employed an intraneural electrode designed for the VN of pigs to perform VN stimulation (VNS). This was delivered using different numbers of contacts on the electrode and different stimulation parameters (amplitude, frequency, and pulse width), identifying the most suitable stimulation configuration. All the parameter ranges had been selected from a computational cardiovascular system model.
Results: Clinically relevant responses were observed when stimulating with low current intensities and relatively low frequencies delivered with a single contact. Selecting a biphasic, charge-balanced square wave for VNS with a current amplitude of 500 μA, frequency of 10 Hz, and pulse width of 200 μs, we obtained heart rate reduction of 7.67 ± 5.19 beats per minute, systolic pressure reduction of 5.75 ± 2.59 mmHg, and diastolic pressure reduction of 3.39 ± 1.44 mmHg.
Conclusion: Heart rate modulation was obtained without inducing any observable adverse effects, underlining the high selectivity of the intraneural approach
A multi-scale regional landslide susceptibility assessment approach: the SUFRA_SICILIA (SUscettibilit\ue0 da FRAna in Sicilia) project
The SUFRA project is based on a three level susceptibility mapping. According to the availability of more detailed data, the three scale for susceptibility mapping are increased respect to the ones suggested by the TIER group to 1:100,000, 1:50,000 and 1:25,000/1:10,000.
The mapping levels exploit climatic, soil use (CORINE2009) and seismic informative layers, differentiating in the details of the core data (geology and topography), in the quality and resolution of the landslide inventory and in the modelling approach (Tab. 1).
SUFRA_100 is based on a heuristic approach which is applied by processing a geologic layer (produced by ARTA integrating pre-CARG 1:100,000 geologic maps); the DEM exploited are IGMI 250m and the mapping units are 1km side square cells. Models are validated with respect to the PAI LIPs (Landslide Identification Points) which are reclassified adopting a simplified scheme. Output cuts of SUFRA100 will be referred to administrative boundaries (provinces).
SUFRA50 is based on statistical analysis of new CARG geologic maps and 20m (ITA2000) - 2m (ATA2007) DEM. The mapping units are 500m and 50m cells, hydrographic and hydro-morphometric units. The landslide inventory is the IFFI2012_LIPs (first level) which is the result of the conversion in IFFI format of the PAI archive, which will be supported by remote landslide mapping (exploiting the ATA2007 aerial photos), according to the IFFI first level approach. Validation of the models will be performed exploiting both random spatial partition and temporal partition methods. Output cuts of SUFRA50 will be based on physiographic (basin) and administrative (municipalities) boundaries.
SUFRA10/25 is based on statistical analysis of new CARG geologic maps (remotely and field adapted) and 2m (ATA2007) DEM. The mapping units are the slope units (SLUs) which are derived by further partitioning the hydro-morphometric units so to obtain closed morphodynamic units. The landslide inventories is the IFFI2012 which is the results of a field supported (on focus) landslide remote systematic mapping, according to the IFFI full level approach.
Examples of SUFRA_100, SUFRA_50 and SUFRA_10 are presented for some representative key sector of Sicily. First results attest for the feasibility and goodness of the proposed protocol.
The SUFRA program aims at enabling the regional governmental administration to cope with landslide prevision, which is the required operational concept in land management and planning. PAI has been a great advance with respect to the \u201cpre-SARNO\u201d conditions, but it is very exposed to fail: it is a blind approach for new activations; it is critically dependent on the quality of the landslide inventories; it cannot project the susceptibility outside the landslide area
CaloCube: a novel calorimeter for high-energy cosmic rays in space
In order to extend the direct observation of high-energy cosmic rays up to
the PeV region, highly performing calorimeters with large geometrical
acceptance and high energy resolution are required. Within the constraint of
the total mass of the apparatus, crucial for a space mission, the calorimeters
must be optimized with respect to their geometrical acceptance, granularity and
absorption depth. CaloCube is a homogeneous calorimeter with cubic geometry, to
maximise the acceptance being sensitive to particles from every direction in
space; granularity is obtained by relying on small cubic scintillating crystals
as active elements. Different scintillating materials have been studied. The
crystal sizes and spacing among them have been optimized with respect to the
energy resolution. A prototype, based on CsI(Tl) cubic crystals, has been
constructed and tested with particle beams. Some results of tests with
different beams at CERN are presented.Comment: Seven pages, seven pictures. Proceedings of INSTR17 Novosibirs
Justification of the symmetric damping model of the dynamical Casimir effect in a cavity with a semiconductor mirror
A "microscopic" justification of the "symmetric damping" model of a quantum
oscillator with time-dependent frequency and time-dependent damping is given.
This model is used to predict results of experiments on simulating the
dynamical Casimir effect in a cavity with a photo-excited semiconductor mirror.
It is shown that the most general bilinear time-dependent coupling of a
selected oscillator (field mode) to a bath of harmonic oscillators results in
two equal friction coefficients for the both quadratures, provided all the
coupling coefficients are proportional to a single arbitrary function of time
whose duration is much shorter than the periods of all oscillators. The choice
of coupling in the rotating wave approximation form leads to the "mimimum
noise" model of the quantum damped oscillator, introduced earlier in a pure
phenomenological way.Comment: 9 pages, typos corrected, corresponds to the published version,
except for the reference styl
Fluctuations, dissipation and the dynamical Casimir effect
Vacuum fluctuations provide a fundamental source of dissipation for systems
coupled to quantum fields by radiation pressure. In the dynamical Casimir
effect, accelerating neutral bodies in free space give rise to the emission of
real photons while experiencing a damping force which plays the role of a
radiation reaction force. Analog models where non-stationary conditions for the
electromagnetic field simulate the presence of moving plates are currently
under experimental investigation. A dissipative force might also appear in the
case of uniform relative motion between two bodies, thus leading to a new kind
of friction mechanism without mechanical contact. In this paper, we review
recent advances on the dynamical Casimir and non-contact friction effects,
highlighting their common physical origin.Comment: 39 pages, 4 figures. Review paper to appear in Lecture Notes in
Physics, Volume on Casimir Physics, edited by Diego Dalvit, Peter Milonni,
David Roberts, and Felipe da Rosa. Minor changes, a reference adde
CaloCube: an innovative homogeneous calorimeter for the next-generation space experiments
The direct measurement of the cosmic-ray spectrum, up to the knee region, is one of the instrumental challenges for next generation space experiments. The main issue for these measurements is a steeply falling spectrum with increasing energy, so the physics performance of the space calorimeters are primarily determined by their geometrical acceptance and energy resolution. CaloCube is a three-year R&D project, approved and financed by INFN in 2014, aiming to optimize the design of a space-born calorimeter. The peculiarity of the design of CaloCube is its capability of detecting particles coming from any direction, and not only those on its upper surface. To ensure that the quality of the measurement does not depend on the arrival direction of the particles, the calorimeter will be designed as homogeneous and isotropic as possible. In addition, to achieve a high discrimination power for hadrons and nuclei with respect to electrons, the sensitive elements of the calorimeter need to have a fine 3-D sampling capability. In order to optimize the detector performances with respect to the total mass of the apparatus, which is the most important constraint for a space launch, a comparative study of different scintillating materials has been performed using detailed Monte Carlo simulation based on the FLUKA package. In parallel to simulation studies, a prototype consisting in 14 layers of 3 x 3 CsI(Tl) crystals per layer has been assembled and tested with particle beams. An overview of the obtained results during the first two years of the project will be presented and the future of the detector will be discussed too
Diode-pumped ultrafast Yb:KGW laser with 56 fs pulses and multi-100 kW peak power based on SESAM and Kerr-lens mode locking
A high-power sub-60Â fs mode-locked diode-pumped Yb:KGW laser based on hybrid action of an InGaAs quantum-dot saturable absorber mirror and Kerr-lens mode locking was demonstrated. The laser delivered 56Â fs pulses with 1.95Â W of average power corresponding to 450Â kW of peak power. The width of the generated laser spectrum was 20.5Â nm, which was near the gain bandwidth limit of the Yb:KGW crystal. To the best of our knowledge, these are the shortest pulses generated from the monoclinic double tungstate crystals (and Yb:KGW laser crystal in particular) and the most powerful in the sub-60Â fs regime. At the same time, they are also the shortest pulses produced to date with the help of a quantum-dot-based saturable absorber. High-power operation with a pulse duration of 90Â fs and 2.85Â W of average output power was also demonstrated
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