262 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
Asymptotical photon distributions in the dissipative Dynamical Casimir Effect
Asymptotical formulas for the photon distribution function of a quantum
oscillator with time-dependent frequency and damping coefficients, interacting
with a thermal reservoir, are derived in the case of a large mean number of
quanta. Different regimes of excitation of an initial thermal state with an
arbitrary temperature are considered. New formulas are used to predict the
statistical properties of the electromagnetic field created in the experiments
on the Dynamical Casimir Effect which are now under preparation.Comment: 11 pages, accepted contribution to CEWQO 2009 proceedings (to appear
in Physica Scripta
Action of the gravitational field on the dynamical Casimir effect
In this paper we analyze the action of the gravitational field on the
dynamical Casimir effect. We consider a massless scalar field confined in a
cuboid cavity placed in a gravitational field described by a static and
diagonal metric. With one of the plane mirrors of the cavity allowed to move,
we compute the average number of particles created inside the cavity by means
of the Bogoliubov coefficients computed through perturbative expansions. We
apply our result to the case of an oscillatory motion of the mirror, assuming a
weak gravitational field described by the Schwarzschild metric. The regime of
parametric amplification is analyzed in detail, demonstrating that our computed
result for the mean number of particles created agrees with specific associated
cases in the literature. Our results, obtained in the framework of the
perturbation theory, are restricted, under resonant conditions, to a short-time
limit.Comment: 2 Figures, comments are welcom
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 ΌA, frequency of 10 Hz, and pulse width of 200 Όs, 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
Neural Stimulation Hardware for the Selective Intrafascicular Modulation of the Vagus Nerve
The neural stimulation of the vagus nerve is able to modulate various functions of the parasympathetic response in different organs. The stimulation of the vagus nerve is a promising approach to treating inflammatory diseases, obesity, diabetes, heart failure, and hypertension. The complexity of the vagus nerve requires highly selective stimulation, allowing the modulation of target-specific organs without side effects. Here, we address this issue by adapting a neural stimulator and developing an intraneural electrode for the particular modulation of the vagus nerve. The neurostimulator parameters such as amplitude, pulse width, and pulse shape were modulated. Single-, and multi-channel stimulation was performed at different amplitudes. For the first time, a polyimide thin-film neural electrode was designed for the specific stimulation of the vagus nerve. In vivo experiments were performed in the adult minipig to validate to elicit electrically evoked action potentials and to modulate physiological functions, validating the spatial selectivity of intraneural stimulation. Electrochemical tests of the electrode and the neurostimulator showed that the stimulation hardware was working correctly. Stimulating the porcine vagus nerve resulted in spatially selective modulation of the vagus nerve. ECAP belonging to alpha and beta fibers could be distinguished during single- and multi-channel stimulation. We have shown that the here presented system is able to activate the vagus nerve and can therefore modulate the heart rate, diastolic pressure, and systolic pressure. The here presented system may be used to restore the cardiac loop after denervation by implementing biomimetic stimulation patterns. Presented methods may be used to develop intraneural electrodes adapted for various applications
Implementation of an epicardial implantable MEMS sensor for continuous and real-time postoperative assessment of left ventricular activity in adult minipigs over a short- and long-term period
The sensing of left ventricular (LV) activity is fundamental in the diagnosis and monitoring of cardiovascular health in high-risk patients after cardiac surgery to achieve better short- and long-term outcome. Conventional approaches rely on noninvasive measurements even if, in the latest years, invasive microelectromechanical systems (MEMS) sensors have emerged as a valuable approach for precise and continuous monitoring of cardiac activity. The main challenges in designing cardiac MEMS sensors are represented by miniaturization, biocompatibility, and long-term stability. Here, we present a MEMS piezoresistive cardiac sensor capable of continuous monitoring of LV activity over time following epicardial implantation with a pericardial patch graft in adult minipigs. In acute and chronic scenarios, the sensor was able to compute heart rate with a root mean square error lower than 2 BPM. Early after up to 1 month of implantation, the device was able to record the heart activity during the most important phases of the cardiac cycle (systole and diastole peaks). The sensor signal waveform, in addition, closely reflected the typical waveforms of pressure signal obtained via intraventricular catheters, offering a safer alternative to heart catheterization. Furthermore, histological analysis of the LV implantation site following sensor retrieval revealed no evidence of myocardial fibrosis. Our results suggest that the epicardial LV implantation of an MEMS sensor is a suitable and reliable approach for direct continuous monitoring of cardiac activity. This work envisions the use of this sensor as a cardiac sensing device in closed-loop applications for patients undergoing heart surgery
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
- âŠ