The effect of trapping superparamagnetic beads on domain wall motion

Domain walls may act as localized field sources to trap and move superparamagnetic beads for manipulating biological cells and DNA. The interaction between beads of various diameters and a wall is investigated using a combination of micromagnetic and analytical models. Domain walls can transport beads under applied magnetic fields but the mutual attraction between the bead and wall causes drag forces affecting the bead to couple into the wall motion. Therefore, the interaction with the bead causes a fundamental change in the domain wall dynamics, reducing the wall mobility by five orders of magnitude. (C) 2010 American Institute of Physics. [doi:10.1063/1.3428775

Transverse field-induced nucleation pad switching modes during domain wall injection

We have used magnetic transmission soft X-ray microscopy (M-TXM) to image in-field magnetization configurations of patterned Ni80F20 domain wall "nucleation pads" with attached planar nanowires. Comparison with micromagnetic simulations suggests that the evolution of magnetic domains in rectangular injection pads depends on the relative orientation of closure domains in the remanent state. The magnetization reversal pathway is altered by the inclusion of transverse magnetic fields. These different modes explain previous results of domain wall injection into nanowires

Direct imaging of domain-wall interactions in Ni80Fe20 planar nanowires

We have investigated magnetostatic interactions between domain walls in Ni80Fe20 planar nanowires using magnetic soft x-ray microscopy and micromagnetic simulations. In addition to significant monopole-like attraction and repulsion effects we observe that there is coupling of the magnetization configurations of the walls. This is explained in terms of an interaction energy that depends not only on the distance between the walls, but also upon their internal magnetization structure

Pengembangan Model Layanan Reservasi Berbasis Web Stasiun Kereta Api Solo Balapan Dengan Antarmuka Bahasa Sehari-hari

Development of web-based reservation service model at the train station Solobalapan with everyday language interface is a system application that makes it easy for the assengers who will make the process of booking train tickets and find information about Solobalapan station online. In a Web-based service system resevasi include any information about the schedule of train travel from the station Solobalapan, booking train tickets, rail passenger data, the cost of train tickets, and other information regarding Solobalapan station. The development of this system using the waterfall method and system design using the design model UML (Unified Modeling Language), and using the programming language PHP using MySQL database.. echniques in data collection using field study consisted of direct observation (observation), interviews and iterature. In this study resulted in the reservation system booking train tickets online using everyday language interface and contains the information about Solobalapan station

Perbaikan Final Drive Planetary Gear Wheel Loader WA320-3CS

Planetary gear final drive is one of the final driving components and as a connector for the power train component with wheels or tracks. The purpose of this study is to find out the mechanism of action, determine the damage, find out the cause of the damage and know the steps to repair the final drive planetary gear. Procedure for checking final drive planetary gear by performing a performance test, and checking visually, then doing a disassembly to check the components, then analyzing the results of the inspection to determine the damage that occurs in the final drive planetary gear. The results of the analysis show that there are damaged planetary gear final drive components, namely pinion gear, pinion gear bearings, ring gear, driveshaft gear so that the final drive planetary gear cannot work optimally. To find out the cause of damage to the planetary gear final drive, an analysis is calculation on the gear, the corrective steps carried out by replacing damaged components

Evaluasi Ergonomi untuk Mengurangi Muskuloskeletal Disorders Menggunakan Metode Novel Ergonomic Postural Assessment ( NERPA) dan Work Ergonomic Risk Assessment (WERA) (Studi Kasus: UKM Cipta Mandiri, Sidowayah, Polanharjo, Klaten)

Musculoskeletal injury is one of the work accidents that are often experienced by workers because of the wrong posture when doing work. Cipta Mandiri is a small business that produces barecore. The process of making barecore in Cipta Mandiri still uses human power so that it creates a lot of unnatural work postures and causes workers to have a health complaint about musculoskeletal disorder.This study uses the Work Ergonomic Risk Assessment (WERA) and Novel Ergonomic Postural Assessment (NERPA) methods to determine how much risk is posed by the posture of the activities carried out by workers. The results of calculations using the two methods show that of the 9 work stations studied were 12 work activities, obtained a medium score on the WERA method, while there were 3 activities that got a score of 7, 1 activity with a score of 6, 2 activities with a score of 5, 3 activities with scores 4, 3 activities with a score of 3 on the NERPA method. The proposal that can be given is the procurement of tools in the form of workpiece containers and changing work activities at the related work stations. Keywords : Ergonomic, MSDs, WERA, NERPA, OH

Dynamics of high-velocity domain wall motion and spin wave excitation in trilayer structures

Propagation of dipolar-coupled transverse domain walls in a permalloy/non-magnetic/permalloy trilayer was investigated using micromagnetic modeling. Circulating stray fields meant that the walls adopted a composite structure with behavior analogous to walls seen in nanotubes. Wall velocities were sensitive to the chirality of the stray field circulation, with velocities of the most favored chirality enhanced by 32% compared with velocities seen in the individual constituent layers just below their Walker breakdown field. Additionally, Walker breakdown was completely suppressed within the trilayer for both chiralities, despite occurring in the constituent layers when modelled in isolation, leading to a maximum of 317% velocity enhancement. Wall velocity saturated around 1100 m/s due to the Cherenkov-like emission of spin waves, comparable to the magnonic regime of nanotubes. By reproducing the advantageous domain wall dynamics of nanotubes within a planar system, we demonstrate that ultrafast magnetic switching may feasibly be realized within a lithographically produced system

Perbandingan Kuat Tekan Dan Serapan Air Paving Block Hydraulic Dengan Variasi Bahan Tambah Fly Ash

Paving block is one of the building materials used as the top layer of the road structure. Paving block is a building material composition made from a mixture of portland cement, water and fine aggregate with or without other additives. The main ingredient most influential in making paving blocks is cement, because inside the cement contains tricalsium silicate (C3S) calcium silicate (C2S). Then added another binder that is Fly Ash. Paving Block in this study used Hydraulic printing press with 1: 4, 1: 6, 1: 8 test specimen with 10% Fly Ash added ingredient in each test specimen and then performed morning and afternoon watering for 10 days later air drying for 10 days and testing done at 21 days. Effect of 10% Fly Ash addition on Paving Block with variation of specimen (1PC + 10% Fly Ash): 4Ps obtained the maximum compressive strength value is 10.278 MPa with minimum water absorption of 10.112%. From the result of the research, it can be concluded that Paving Block can be included in the quality of D used for garden and other usage. So in the next research is expected to research to try various variations of the addition of Fly Ash, Fly Ash functioned as a substitute for cement as a binder so obtained economic terms resulting from the replacement of cement into Fly Ash as a binder

Bailing Out the Milky Way: Variation in the Properties of Massive Dwarfs Among Galaxy-Sized Systems

Recent kinematical constraints on the internal densities of the Milky Way's dwarf satellites have revealed a discrepancy with the subhalo populations of simulated Galaxy-scale halos in the standard CDM model of hierarchical structure formation. This has been dubbed the "too big to fail" problem, with reference to the improbability of large and invisible companions existing in the Galactic environment. In this paper, we argue that both the Milky Way observations and simulated subhalos are consistent with the predictions of the standard model for structure formation. Specifically, we show that there is significant variation in the properties of subhalos among distinct host halos of fixed mass and suggest that this can reasonably account for the deficit of dense satellites in the Milky Way. We exploit well-tested analytic techniques to predict the properties in a large sample of distinct host halos with a variety of masses spanning the range expected of the Galactic halo. The analytic model produces subhalo populations consistent with both Via Lactea II and Aquarius, and our results suggest that natural variation in subhalo properties suffices to explain the discrepancy between Milky Way satellite kinematics and these numerical simulations. At least ~10% of Milky Way-sized halos host subhalo populations for which there is no "too big to fail" problem, even when the host halo mass is as large as M_host = 10^12.2 h^-1 M_sun. Follow-up studies consisting of high-resolution simulations of a large number of Milky Way-sized hosts are necessary to confirm our predictions. In the absence of such efforts, the "too big to fail" problem does not appear to be a significant challenge to the standard model of hierarchical formation. [abridged]Comment: 12 pages, 3 figures; accepted by JCAP. Replaced with published versio

Unbound Particles in Dark Matter Halos

We investigate unbound dark matter particles in halos by tracing particle trajectories in a simulation run to the far future (a = 100). We find that the traditional sum of kinetic and potential energies is a very poor predictor of which dark matter particles will eventually become unbound from halos. We also study the mass fraction of unbound particles, which increases strongly towards the edges of halos, and decreases significantly at higher redshifts. We discuss implications for dark matter detection experiments, precision calibrations of the halo mass function, the use of baryon fractions to constrain dark energy, and searches for intergalactic supernovae.Comment: Significant improvements following referee suggestion