Optimization of a type of elastic metamaterial for broadband wave suppression

The optimal design is studied for a type of one-dimensional dissipative metamaterial to achieve broadband wave attenuation at low-frequency ranges. The complex dispersion analysis is made on a super-cell consisting of multiple mass-in-mass unit cells. An optimization algorithm based on the sequential quadratic programming method is used to design the wave suppression of target frequencies by coupling multiple separate narrow bandgaps into a broad bandgap. A new objective function is proposed in the optimization process for a continuous bandgap. Then, the continuous frequency range with low-wave transmissibility is optimized to achieve the maximal width of bandgap. The stiffness optimization of super-cell gives the broad bandgap from 10 Hz to 22.9 Hz at low-frequency ranges. In addition, numerical simulations are conducted for a type of dissipative metamaterial composed of a finite number of periodicities. The level of vibration isolation can be tuned by adjusting a critical value in the optimization scheme. The wave suppression in the numerical simulation well coincides with the obtained bandgaps and verifies the optimization results.

IMPLEMENTASI SWOT STRATEGI PEMASARAN ONLINEPADA COUNTER SUPER CELL DI KECAMATAN RIMBO BUJANG KABUPATEN TEBO

Penelitian ini bertujuan untuk mengetahui penjualan produk kepadakonsumen dan ingin lebih tahu banyak tentang produk apa yang ditawarkan.Dari dua strategi yang lebih baik dan lebih efektif untuk dilakukan sehinggaproduk dapat digunakan dan dibeli oleh masyaraka. Penelitian ini menggunakanmetode kualitatif dan analisis deskriptif yang menggunakan analisis SWOTMetode kualitatif seperti Metode Observasi, yaitu metode data denganpengamatan langsung ke counter Super Cell Kecamatan Rimbo BujangKabupaten Tebo dalam memasarkan produk. Dalam penelitian ini penulismengambil data pada Counter Super Cell .Hasil dalam penelitian ini menunjukan bahwa pemasaran online counter Super Cell masuk pada tipe kuadran I. Posisi ini menandakan bahwa counter Super Cell berada di posisi yang kuat dan berpeluang, sehingga sangat memungkinkan untuk terus melakukan pemasaran secara online dan meraih kemajuan secara maksimal. Sedangkan pada analisis SWOT dengan membandingkan nilai IFAS dan EFAS menunjukan bahwa counter Super Cell berada pada situasi SO (strength, opportunities) dengan nilai 7,81 sehingga dapat disimpulkan bahwa strategi pemasaran secara online merupakan posisi yang sangat menguntungkan bagi counter Super Cell memiliki kekuatan dan peluang yang dapat digunakan secara maksimal dalam memasarkan produk secara online. Kata Kunci: Implementasi SWOT Pemasaran Online Dan Offline

Double-Hybrid DFT Functionals for the Condensed Phase: Gaussian and Plane Waves Implementation and Evaluation

Intermolecular interactions play an important role for the understanding of catalysis, biochemistry and pharmacy. Double-hybrid density functionals (DHDFs) combine the proper treatment of short-range interactions of common density functionals with the correct description of long-range interactions of wave-function correlation methods. Up to now, there are only a few benchmark studies available examining the performance of DHDFs in condensed phase. We studied the performance of a small but diverse selection of DHDFs implemented within Gaussian and plane waves formalism on cohesive energies of four representative dispersion interaction dominated crystal structures. We found that the PWRB95 and ωB97X-2 functionals provide an excellent description of long-ranged interactions in solids. In addition, we identified numerical issues due to the extreme grid dependence of the underlying density functional for PWRB95. The basis set superposition error (BSSE) and convergence with respect to the super cell size are discussed for two different large basis sets.

Substrate temperature effect on structural, electronic and optical properties of V2O5 thin films: experimental and ab initio study

Optical, structural and electronic properties of vanadium pentoxide (V2O5) thin films deposited with different values of substrate temperature have been investigated. First principles calculations were performed using the Full Potential Projector-Augmented Wave (PAW) method with the Generalized Gradient Approximation (GGA) implemented in Quantum Espresso code. The results are very promising and show that the temperature has an important effect on V2O5 thin films features. Dielectric functions for different thin films are calculated for 14-atom orthorhombic super-cell structure. The calculated band gaps are fitted with a linear equation: (αhv) 2 = A (hv − Eg) . For all types of deposited thin films the position of critical points (CPs) E0, E1 and E2 show good agreement with the experimental data.

Generation of over 1000 Diffraction Spots from 2D Graded Photonic Super-Crystals

For the first time, we are able to generate over 1000 diffraction spots from a graded photonic super-crystal with a unit super-cell size of 12a × 12a where a is the lattice constant and hole radii are gradually changed in dual directions. The diffraction pattern from the graded photonic super-crystal reveals unique diffraction properties. The first order diffractions of (±1,0) or (0,±1) disappear. Fractional diffraction orders are observed in the diffraction pattern inside a square with vertices of (1,1), (1,−1), (−1,−1) and (−1,−1). The fractional diffraction can be understood from lattices with a period of a. However, a dual-lattice model is considered in order to explain higher-order diffractions. E-field intensity simulations show a coupling and re-distribution among fractional orders of Bloch waves. There are a total of 12 × 12 spots in E-field intensity in the unit supercell corresponding to 12 × 12 fractional diffraction orders in the diffraction pattern and 12 × 12 fractional orders of momentum in the first Brillouin zone in k-space.