Sistem Pengendali Kecepatan Motor Dc Pada Lift Barang Menggunakan Kontroler Pid Berbasis Atmega 2560

Lift barang adalah angkutan transportasi vertikal digunakan untuk memindahkan barang. Lift ini sangat khusus fungsinya untuk barang saja, lift ini hampir sama dengan lift penumpang namun ada sedikit perbedaan dalam sistem keamanannya. Lift barang yang sekarang memang sudah otomatis tetapi hanya pada gedung bertingkat tinggi. Untuk minimarket atau home industry yang memiliki struktur bangunan 2 lantai, banyak dijumpai masih menggunakan pengkatrolan secara manual oleh tenaga manusia untuk memindahkan barang. Hal ini cukup tidak efisien. Pada penelitian ini telah dirancang sistem pengaturan kecepatan motor DC pada lift barang menggunakan kontoler PID dengan kontruksi sistem yang sederhana. Digunakan Kontroler PID untuk mengurangi kesalahan, sehingga putaran motor dapat sesuai dengan kecepatan yang diinginkan. Dengan bantuan kontroler PID maka lift barang mampu bergerak dengan aman dan halus. Pada skripsi ini digunakan metode Ziegler-Nichols tunning 2. Dalam pembuatannya digunakan Arduino Mega 2560, rotary encoder Autonic E40H8 500-6-L-5, limit switch, dan motor DC. Berdasarkan data respons sistem yang diperoleh dari pengujian dengan menggunakan metode kedua Ziegler-Nichols, maka parameter kontroler PID dapat ditentukan dengan gain Kp = 7.71, Ki = 7.035 dan Kd = 2.113.Kata Kunci— Lift barang, Pengendalian Kecepatan, PID, Arduino Mega 2560

Morphology Dependence of Catalytic Properties of Ni/CeO₂ Nanostructures for Carbon Dioxide Reforming of Methane

The comparative catalytic activity and coke resistance are examined in carbon dioxide reforming of methane over Ni/CeO₂ nanorods (NR) and nanopolyhedra (NP). The Ni/CeO₂–NR catalysts display more excellent catalytic activity and higher coke resistance compared with the Ni/CeO₂–NP. The high resolution transmission electron microscope reveals that the predominantly exposed planes are the unusually reactive {110} and {100} planes on the CeO₂–NR rather than the stable {111} one on the CeO₂–NP. The prepared samples were also characterized by X-ray diffraction, transmission electron microscopy, hydrogen temperature-programmed reduction, X-ray photoelectron spectroscopy, UV and visible Raman spectra, and oxygen temperature-programmed oxidation. The {110} and {100} planes show great superiority for the anchoring of Ni nanoparticles, which results in the existence of strong metal–support interaction effect (SMSI). The SMSI effect can be helpful to prevent sintering of Ni particles, which benefits to reduce the deactivation of catalytic activity. Besides, the oxygen vacancies and the mobility of lattice oxygen also show the morphology dependence. They can participate into the catalytic reaction and be beneficial to the activation of carbon deposition. In conclusion, the excellent catalytic activity and coke resistance of the Ni/CeO₂–NR should be attributed to the SMSI effect and abundant oxygen vacancies

Ubiquity of the 5 plant groups in North China between 33 and 5 ka cal BP.

<p>Ubiquity of the 5 plant groups in North China between 33 and 5 ka cal BP.</p

Photographs of <i>Setaria</i> grains.

<p>1 = Z668, 2 = Z335, 3 = Z399, 4 = Z557, 5 = Z280, 6 = Z169, 7 = Z737, 8 = Z734, 9 = W28, 10 = Qing24, 11 = Qing68, 12 = Qing44, 13 = Qing46, 14 = Qing28, 15 = Qing7-1, 16 = Qing59.</p

Ubiquity of the 5 plant groups in North China between 33 and 5 ka cal BP.

<p>Ubiquity of the 5 plant groups in North China between 33 and 5 ka cal BP.</p

Rational Design of High-Performance DeNO_<i>x</i> Catalysts Based on Mn_<i>x</i>Co_3–<i>x</i>O₄ Nanocages Derived from Metal–Organic Frameworks

Herein, we have rationally designed and originally developed a high-performance deNO_<i>x</i> catalyst based on hollow porous Mn_<i>x</i>Co_3–<i>x</i>O₄ nanocages with a spinel structure thermally derived from nanocube-like metal–organic frameworks (Mn₃[Co­(CN)₆]₂·<i>n</i>H₂O), which are synthesized via a self-assemble method. The as-prepared catalysts have been characterized systematically to elucidate their morphological structure and surface properties. As compared with conventional Mn_<i>x</i>Co_3–<i>x</i>O₄ nanoparticles, Mn_<i>x</i>Co_3–<i>x</i>O₄ nanocages possess a much better catalytic activity at low-temperature regions, higher N₂ selectivity, more extensive operating-temperature window, higher stability, and SO₂ tolerance. The feature of hollow and porous structures provides a larger surface area and more active sites to adsorb and activate reaction gases, resulting in the high catalytic activity. Moreover, the uniform distribution and strong interaction of manganese and cobalt oxide species not only enhance the catalytic cycle but also inhibit the formation of manganese sulfate, resulting in high catalytic cycle stability and good SO₂ tolerance. In light of the various characterization results, the excellent deNO_<i>x</i> performance of Mn_<i>x</i>Co_3–<i>x</i>O₄ nanocages can be attributed to the hollow and porous structures, the uniform distribution of active sites, as well as the strong interaction of manganese and cobalt oxide species. The excellent catalytic performance suggests that Mn_<i>x</i>Co_3–<i>x</i>O₄ nanocages are promising candidates for low-temperature deNO_<i>x</i> catalysts. More importantly, the present study indicates that the hollow porous architectures and well-dispersed active components can effectively enhance the performance of catalysts

Comparison of the ubiquity for several cereals, weeds, and edible wild plants in North China between 33 and 5 ka cal BP.

<p>Comparison of the ubiquity for several cereals, weeds, and edible wild plants in North China between 33 and 5 ka cal BP.</p

Papillae distribution on surfaces of the upper lemmas from foxtail millet and green foxtail.

<p>Papillae distribution on surfaces of the upper lemmas from foxtail millet and green foxtail.</p

Classification results of discriminant analysis for ΩIII type phytolith.

<p>78.4% of foxtail millet and 76.9% of green foxtail are classified accurately.</p

Comparison in the relative percentage (shaded color) and percentage ubiquity (solid color) of foxtail millet and common millet in North China at 9~6 and 6~5 ka cal BP.

<p>Comparison in the relative percentage (shaded color) and percentage ubiquity (solid color) of foxtail millet and common millet in North China at 9~6 and 6~5 ka cal BP.</p