PENGARUH DOSIS PUPUK N DAN TANAMAN SELA KACANG TANAH (Arachis hypogaea L.) PADA PERTUMBUHAN SERTA HASIL TANAMAN JAGUNG (Zea mays L.) YANG DITANAM SECARA TUMPANGSARI

Salah satu upaya yang dapat dilakukan untuk meningkatkan produksi tanaman jagung ialah melalui pertanaman secara  tumpangsari. Tujuan penelitian ialah Untuk mengetahui tingkat efisiensi dosis pupuk nitrogen dalam pembudidayaan tanaman jagung secara tumpangsari dan untuk mengetahui pengaruh tanaman sela kacang tanah terhadap pertumbuhan serta hasil tanaman jagung dalam sistem tumpangsari. Percobaan dilaksanakan pada bulan Juli sampai November 2014 di Desa Tegalgondo, Kecamatan Karangploso, Malang. Rancangan yang digunakan dalam penelitian ini adalah Rancangan Acak Kelompok (RAK) yang terdiri dari 9 kombinasi perlakuan dan 3 ulangan. Perlakuan terdiri dari P1K1 (30 kg N ha-1 1 tanaman sela), P2K1 (60 kg N ha-1 1 tanaman sela), P3K1 (90 kg N ha-1 1 tanaman sela), P1K2 (30 kg N ha-1 2 tanaman sela), P2K2 (60 kg N ha-1 2 tanaman sela), P3K2 (90 kg N ha-1 2 tanaman sela), P1K3 (30 kg N ha-1 3 tanaman sela), P2K3 (60 kg N ha-1 3 tanaman sela), P3K3 (90 kg N ha-1 3 tanaman sela). Hasil penelitian menunjukkan bahwa kombinasi perlakuan dosis 90 kg N ha-1 dan 1 tanaman sela memberikan hasil panen (t ha-1) berbeda nyata terhadap kombinas perlakuan dosis  30 kg N ha-1 1 tanaman sela. , tetapi kombinasi perlakuan 90 kg N ha-1 dan 1 tanaman sela tidak berbeda nyata dengan perlakuan lainnya

Oscillatory fracture path in thin elastic sheet

We report a novel mode of oscillatory crack propagation when a cutting tip is driven through a thin brittle polymer film. The phenomenon is so robust that it can easily be reproduced at hand (using CD packaging material for example). Careful experiments show that the amplitude and wavelength of the oscillatory crack path scale lineraly with the width of the cutting tip over a wide range of lenghtscales but are independant of the width of thje sheet and the cutting speed. A simple geometric model is presented, which provides a simple but thorough interpretation of the oscillations.Comment: 6 pages, submitted to Comptes Rendus Academie des Sciences. Movies available at http://www.lmm.jussieu.fr/platefractur

Enhancement of electrostrictive polymer efficiency for energy harvesting with cellular polypropylene electrets

The purpose of this paper is to propose new means for harvesting energy using electrostrictive polymers. The recent development of electrostrictive polymers has generated new opportunities for high-strain actuators. At the current time, the investigation of using electrostrictive polymer for energy harvesting, or mechanical-to-electrical energy conversion, is beginning to show its potential for this application. The objective of this work was to study the effect of cellular polypropylene electrets after high-voltage corona poling on an electrostrictive polyurethane composite filled with 1 vol.% carbon black at a low applied voltage in order to increase the efficiency of the electromechanical conversion with electrostrictive polymers. Theoretical analysis supported by experimental investigations showed that an energy harvesting with this structure rendered it possible to obtain harvested power up to 13.93 nW using a low electric field of 0.4 V/mu m and a transverse strain of 3% at a mechanical frequency of 15 Hz. This represents an efficiency of 78.14% at low frequency. This percentage is very significant compared to other structures. Finally, it was found that the use of polypropylene electrets with electrostrictive polymers was the best way to decrease the power of polarization in order to obtain a good efficiency of the electromechanical conversion for energy harvesting

Rifts in Spreading Wax Layers

We report experimental results on the rift formation between two freezing wax plates. The plates were pulled apart with constant velocity, while floating on the melt, in a way akin to the tectonic plates of the earth's crust. At slow spreading rates, a rift, initially perpendicular to the spreading direction, was found to be stable, while above a critical spreading rate a "spiky" rift with fracture zones almost parallel to the spreading direction developed. At yet higher spreading rates a second transition from the spiky rift to a zig-zag pattern occurred. In this regime the rift can be characterized by a single angle which was found to be dependent on the spreading rate. We show that the oblique spreading angles agree with a simple geometrical model. The coarsening of the zig-zag pattern over time and the three-dimensional structure of the solidified crust are also discussed.Comment: 4 pages, Postscript fil

Imprinting the memory into paste and its visualization as crack patterns in drying process

In the drying process of paste, we can imprint into the paste the order how it should be broken in the future. That is, if we vibrate the paste before it is dried, it remembers the direction of the initial external vibration, and the morphology of resultant crack patterns is determined solely by the memory of the direction. The morphological phase diagram of crack patterns and the rheological measurement of the paste show that this memory effect is induced by the plasticity of paste.Comment: 4 pages, 3 figures, submitted to JPS

Azetidine synthesis by La(OTf)3-catalyzed intramolecular regioselective aminolysis of cis-3,4-epoxy amines

Azetidine is a prevalent structural motif found in various biologically active compounds. In this research paper, we report La(OTf)3-catalyzed intramolecular regioselective aminolysis of cis-3,4-epoxy amines to afford azetidines. This reaction proceeded in high yields even in the presence of acid-sensitive and Lewis basic functional groups

Oscillating Fracture in Rubber

We have found an oscillating instability of fast-running cracks in thin rubber sheets. A well-defined transition from straight to oscillating cracks occurs as the amount of biaxial strain increases. Measurements of the amplitude and wavelength of the oscillation near the onset of this instability indicate that the instability is a Hopf bifurcation

Finger Motion Classification by Forearm Skin Surface Vibration Signals

The development of prosthetic hand systems with both decoration and motion functionality for hand amputees has attracted wide research interests. Motion-related myoelectric potentials measured from the surface of upper part of forearms were mostly employed to construct the interface between amputees and prosthesis