Multiscale Kinetic Monte-Carlo for Simulating Epitaxial Growth

We present a fast Monte-Carlo algorithm for simulating epitaxial surface growth, based on the continuous-time Monte-Carlo algorithm of Bortz, Kalos and Lebowitz. When simulating realistic growth regimes, much computational time is consumed by the relatively fast dynamics of the adatoms. Continuum and continuum-discrete hybrid methods have been developed to approach this issue; however in many situations, the density of adatoms is too low to efficiently and accurately simulate as a continuum. To solve the problem of fast adatom dynamics, we allow adatoms to take larger steps, effectively reducing the number of transitions required. We achieve nearly a factor of ten speed up, for growth at moderate temperatures and large D/F.Comment: 7 pages, 6 figures; revised text, accepted by PR

Perbandingan Kondisi Optimum Pereduksi Natrium Tiosulfat (Na2S2O3) Dan Hidroksilamin Hidroklorida (NH2OH.HCl) Pada Analisa Kadar Total Besi Secara Spektrofotometri UV-Vis

Pada penelitian ini dibandingkan aktivitas pereduksi Na2S2O3 dan NH2OH.HCl yang meliputi pH optimum, waktu pembentukan kompleks dan konsentrasi optimum. Penentuan maks diperoleh pada 512 nm. Selanjutnya optimasi pH buffer suasana asam diperoleh pH 4,5 untuk pereduksi Na2S2O3 dan pH 5,5 untuk NH2OH.HCl. Kedua pereduksi masing-masing dapat mereduksi optimum pada pendiaman 15 menit. Na2S2O3 ditemukan masih stabil di atas 15 menit, sedangkan NH2OH.HCl sudah rusak. Selain itu, dilakukan penentuan konsentrasi optimum pereduksi, dihasilkan 10 ppm pereduksi Na2S2O3 dan 11 ppm NH2OH.HCl untuk mereduksi 5 ppm larutan Fe3+

First Measurement of the Double Spin Asymmetry in e⃗ p⃗ →e′π+n in the Resonance Region

The double spin asymmetry in the ep→e′π+n reaction has been measured for the first time in the resonance region for four-momentum transfer Q2=0.35–1.5GeV2. Data were taken at Jefferson Lab with the CLAS detector using a 2.6 GeV polarized electron beam incident on a polarized solid NH3 target. Comparison with predictions of phenomenological models shows strong sensitivity to resonance contributions. Helicity- 1/2 transitions are found to be dominant in the second and third resonance regions. The measured asymmetry is consistent with a faster rise with Q2 of the helicity asymmetry A1 for the F15(1680) resonance than expected from the analysis of the unpolarized data

Implementasi Algoritma Fuzzy Logic Pada Robot Arm Dengan Memanfaatkan Accelerometer Smartphone Android

Now the development of smart phone technology has evolved rapid, especially Smartphone Android. Where multiple sensors embedded in a mobile phone, primarily an accelerometer sensor support be used of smartphone phone. Accelerometer is used to measure the acceleration reviews Angle X, Y and Z smartphone. So that the sensor is used to review the Movement Robot Arm matching is done with corner acceleration motion X, Y and Z smartphone Method on the system is backed with Fuzzy Logic the which serves to Determine the movement of the robot arm that is sent to the microcontroller. Arm robot system is processed using Matlab 6.1 and using the Software Arduino, and then implanted into the microcontroller, so that the robot goes According movement. Keywords : Android, Accelerometer, Robot Arm, Fuzzy Logi

Penerapan Model Pembelajaran Kooperatif TIME Token Untuk Meningkatkan Prestasi Belajar Siswa Pada Pokok Bahasan Reaksi Reduksi Oksidasi Di Kelas X SMA Negeri 2 Siak Hulu

Research on the application of cooperative learning model Time Token has been conducted to improve student learning achievement on the topic stoichiometry at class X SMAN 2 Siak Hulu. This research is experimental research with randomized control group pretest-posttest design. The sample took in the month February – maret 2013. The sample consisted of two class, X3 class as control class. Experimental class is the with cooperative learning model Time Token and Control Class is the class with cooperative learning model Time Token. Analyze of data by used t-test formula. Result of data processing obtained t count>t table is 2,07 > 1,67. It means that the application of cooperative learning model Time Token can improve student achievement on the topic redoks at class X SMAN 2 Siak Hulu with the increasing percentage of 6,299%

Evaluasi Potensi Jalur Trekking Hutan Pendidikan USU, Taman Hutan Raya Bukit Barisan, Kabupaten Karo (Evaluation of Potential Tracking Rute at Educational Forest of USU, Bukit Barisan Grand Forest Park, Regency of Karo)

Educational Forest of USU has many interesting objects, unfortunately it has not had development activity yet that can support Educational Forest of USU as a ecotourism destination. Therefore, a research about potential evaluation of ecotourism had been conducted at track of Educational Forest of USU in July – August 2012. This research aimed to evaluate the potential use of track of Educational Forest of USU for ecotourism activities. The research was conducted by using force field analysis method to decide supporting factors and obstacle factors that influenced at Educational Forest of USU. Usu has many ecotourism potencies such as the beauty of nature, flora and fauna. Educational Forest of USU has excellent potential to be developed as a tourist area and needs a great strategy from the administrator to be an interesting ecotourism region