SOFT MAGNETIC Fe-BASED METALLIC GLASSES PREPARED BY FLUXING AND WATER-QUENCHING

Abstract. [(Fe 0.5 Co 0.5 ) 0.75 B 0.20 Si 0.05 ] 96 Nb 4 soft magnetic bulk metallic glasses were prepared by fluxing and water-quenching in a silica tube. Dimension of the bulk metallic glass specimens was up to 7.7 mm in diameter, which is about 1.5 times larger than those prepared by Cu mold-casting. The critical cooling rate of [(Fe 0.5 Co 0.5 ) 0.75 B 0.20 Si 0.05 ] 96 Nb 4 alloys with fluxing for forming a metallic glass phase was 150 -170 K/s, which was considerably smaller than that without fluxing. Saturation magnetization was 1.13 T, and coercivity was lower than 20 A/m. Fluxing suppresses heterogeneous nucleation by isolating the nucleation sites from the molten alloys and improves their glass-forming ability

Exploiting open source 3D printer architecture for laboratory robotics to automate high-throughput time-lapse imaging for analytical microbiology

Growth in open-source hardware designs combined with the low-cost of high performance optoelectronic and robotics components has supported a resurgence of in-house custom lab equipment development. We describe a low cost (below USD700), open-source, fully customizable high-throughput imaging system for analytical microbiology applications. The system comprises a Raspberry Pi camera mounted on an aluminium extrusion frame with 3D-printed joints controlled by an Arduino microcontroller running open-source Repetier Host Firmware. The camera position is controlled by simple G-code scripts supplied from a Raspberry Pi singleboard computer and allow customized time-lapse imaging of microdevices over a large imaging area. Open-source OctoPrint software allows remote access and control. This simple yet effective design allows high-throughput microbiology testing in multiple formats including formats for bacterial motility, colony growth, microtitre plates and microfluidic devices termed ‘lab-on-a-comb’ to screen the effects of different culture media components and antibiotics on bacterial growth. The open-source robot design allows customization of the size of the imaging area; the current design has an imaging area of ~420 × 300mm, which allows 29 ‘lab-on-a-comb’ devices to be imaged which is equivalent 3480 individual 1μl samples. The system can also be modified for fluorescence detection using LED and emission filters embedded on the PiCam for more sensitive detection of bacterial growth using fluorescent dyes

Basic Study on an Optical Network Module Using Surface Emitting Lasers

Introduction The key part of the optical network module that we are proposing[1],[2] is a two dimensional optical element consisted of the vertical cavity surface-emitting laser (VCSEL) arrays and the switching devices with optical filter. In this paper, we report on a study of the fabrication technologies of a distributed Bragg reflector (DBR) for VCSEL and optical filter for the switching devices, and the basic experiments on multiwavelength free-space optical transmissions using the optical wavelength filter as a part of fundamental signal transmission experiments for an optical network module. 2. Distributed Bragg reflector The schematic structure of the VCSEL is shown in Fig. 1. In the present study, we use GaAs/AlAs superlattice (SL) layers in DBR, which is epitaxially-grown by using MBE method. The SL layer consisted of 12.5-pair GaAs/AlAs, while the basic structure of DBR consisted of 25-pair AlAs/SL as shown in Fig. 2. Fig. 3 shows the reflectivity spectra of the DBR consisti

Proposal for an Optical Network Module Using Surface Emitting Lasers

this paper, we report on a study of GaAlAs surface emitting lasers, and propose a reconfigurable and compact optical network module using surface emitting lasers for optical interconnection. 2. GaAlAs surface emitting lasers The schematic structure of the buried heterostructure distributed Bragg reflector (DBR) surface emitting (SE) lasers is shown in Fig.1. Light output is obtained through a top-side reflector consisting of a 4-pair SiO 2 /TiO 2 DBR. An n-type 25-pair GaAlAs/AlAs epitaxially-grown stacked layer is used as a bottom-side DBR with very high reflectivity of more than 99 %. A p-type Ga 1-x Al x As active layer is buried at about 10 µmf in diameter with a currrent blocking layer, thereby allowing nearly 1