Insertion of Vertically Aligned Nanowires into Living Cells by Inkjet Printing of Cells

Effective insertion of vertically aligned nanowires (NWs) into cells is critical for bioelectrical and biochemical devices, biological delivery systems, and photosynthetic bioenergy harvesting. However, accurate insertion of NWs into living cells using scalable processes has not yet been achieved. Here, NWs are inserted into living Chlamydomonas reinhardtii cells (Chlamy cells) via inkjet printing of the Chlamy cells, representing a low‐cost and large‐scale method for inserting NWs into living cells. Jetting conditions and printable bioink composed of living Chlamy cells are optimized to achieve stable jetting and precise ink deposition of bioink for indentation of NWs into Chlamy cells. Fluorescence confocal microscopy is used to verify the viability of Chlamy cells after inkjet printing. Simple mechanical considerations of the cell membrane and droplet kinetics are developed to control the jetting force to allow penetration of the NWs into cells. The results suggest that inkjet printing is an effective, controllable tool for stable insertion of NWs into cells with economic and scale‐related advantages.     

Localized Electrochemical Deposition of Copper Monitored Using Real‐Time X‐ray Microradiography

We have developed a novel strategy for localized electrochemical deposition (LECD) to improve both the lateral resolution of the process and the porosity of the fabricated high‐aspect‐ratio microstructures. The strategy is based on accurately controlling the motion of the anode. Its implementation is made possible by the use of coherent, synchrotron X‐ray microradiography with high time and lateral resolution, enabling the observation of the copper LECD process in real time. Microradiography reveals a deposition mechanism that differs as a function of the distance between the electrode (anode) and the growing structure (cathode). Specifically, the interplay of migration and diffusion of the metal ions in the baths affects the deposition rate and the characteristics of the fabricated structure. This enables us to optimize the anode motion control and greatly improve the quality of the structure grown.     

Photoluminescence and low-voltage cathodoluminescence characteristics of blue phosphor, ZnGa2O4:M (M = Na, Ag)

Photoluminescence and low-voltage cathodoluminescence characteristics of ZnGa₂O₄ phosphor doped with monovalent ions has been studied. Monovalent ions such as Na⁺ and Ag⁺ are incorporated into ZnGa₂O₄ lattices in order to increase the concentration of oxygen vacancies in the spinel lattice. By doping low concentrations of monovalent ions (Na⁺, Ag⁺) into ZnGa₂O₄, the self-activated blue luminescence originated from oxygen vacancies is enhanced. Also, the blue luminescence intensity is enhanced more along with a good color purity by annealing ZnGa₂O₄:Na⁺ in a reducing atmosphere, which is due to increasing the concentration of oxygen vacancies even more. The luminescence band at the UV region (λ_max=360 nm) does not become the major luminescence band by introducing Na⁺ ion into the ZnGa₂O₄ lattice, while the UV luminescence band becomes the major one by annealing the undoped ZnGa₂O₄ in a reducing atmosphere.     

A study on the restoration method of friction, wear and fatigue performance of remanufactured crankshaft

Crankshaft translates reciprocating linear piston motion into rotation in internal combustion engine. So it receives complex combination of stresses. Therefore, crankshaft remanufacturing process is designed thoroughly with special attention to fatigue and tribological performance. Experimental study is carried out in order to show that UNSM (ultrasonic nanocrystal surface modification) technology which will be used as final surface treatment after 0.2 mm depth surface grinding, could restore original fatigue strength and tribological performance. Furthermore the feasibility steady to replace conventional overlay welding in crankshaft remanufacturing process by UNSM (ultrasonic nanocrystal surface modification) technology is carried out. Effects of UNSM technology are established through rotary bending test, rolling contact fatigue (RCF) test and wear simulation test. The test specimen used SCM435 material of crankshaft and commercial bush. The test result showed fatigue limit improved by 30% and RCF life increased by 40% for UNSM treated specimen. And friction coefficient decreased by 24% and wear amount decreased by 85%.     

A new slideline/eroding algorithm for EPIC2

This paper describes a new slideline/eroding algorithm implemented into EPIC2 code (Johnson , 1986). It also presents some results of impact calculations which show that this new algorithm not only better resolved the interface between two impacting bodies, but also smoothed out the curvature of the slideline. This was all done without an undue increase of CPU (central processing unit) time.     

Corrosion and wear characteristics of pulse-plated chromium deposits

Corrosion and wear characteristics of pulse-plated chromium deposits, obtained from a self-regulating highspeed (SRHS) bath have been studied as a function of pulse current parameters such as duty cycle, average current density and pulse period. The chromium deposits obtained at duty cycles of 100 (direct current) to 60% were composed of a hemispherical nodular growth with a body centred cubic (b c c) lattice while those obtained at 20% duty cycle were composed of a needle-like structure containing a mixture of b c c lattice and hexagonal hydride. Corrosion rate, wear loss of chromium deposits and occluded hydrogen content in the deposits decreased up to 60% duty cycle, and then increased with further decrease in duty cycle to 20%. A two-stage variation of corrosion and wear properties with decreasing duty cycle is discussed in terms of crack density and the crystal structure of chromium deposits.     

Relationship between hydrogen-assisted crack propagation rate and the corresponding crack path in AISI 4340 steel

In the present investigation, relationship between hydrogen-assisted (HA) crack propagation rate and the corresponding fracture mode in AISI 4340 steel has been elucidated with critical hydrogen concentration concept. Hydrogen assisted crack-propagation rate and the corresponding fracture surface morphology were determined from double cantilever beam (DCB) specimens as a function of hydrogen pressure and temperature. As hydrogen pressure decreased, threshold stress intensity factor necessary for the onset of hydrogen-assisted crack propagation increased and the stage II (plateau) crack-propagation rate decreased. The kinetics of stage II crack propagation indicated substantial difference, i.e., positive and negative responses in the two investigated low and high temperature regions, respectively. Fractographic analysis showed that increased amounts of the microvoid coalescence mode resulted in slower crack-propagation rates. The observed changes in crack-propagation rate and the corresponding fracture mode with hydrogen pressure and temperature are discussed in terms of critical stress or strain and critical hydrogen concentration concepts.     

Improvement of linewidth enhancement factor in 1.55-μmmultiple-quantum-well laser diodes

The improvement of the linewidth enhancement factor in complex-coupled laser diode (CC-LD), or loss-coupled, was confirmed by measuring the spontaneous emission spectra below threshold from the sidewall of laser diodes. In addition, the serial resistance of the device was measured. The linewidth enhancement factor is improved by the presence of a light absorbing InGaAs grating for loss coupled distributed-feedback (DFB) laser diode (LD). We report the comparison of the linewidth enhancement factors of Fabry-Perot (FP) LD, conventional DFB-LD, and loss coupled DFB-LDs     

Calretinin and calbindin D28K immunoreactivity in the superficial layers of the rabbit superior colliculus

Calretinin and calbindin D28K were localized in the superficial layers of rabbit superior colliculus (SC). Calretinin and calbindin D28K-immunoreactive (-IR) neurons were concentrated in the upper superficial gray layer. Calretinin-IR fibers were found in the optic layer. The majority of calretinin-IR cells were small- to medium-sized vertical fusiform neurons and neurons with round or stellate-shaped somas with small varicose dendrites. The morphology of calbindin D28 K-IR neurons was different from that of calretinin neurons. Anti-calbindin D28K-IR neurons usually had fusiform cell bodies and a thick primary dendrite with small branches forming a dendritic bouquet. Two-color immunofluorescence revealed that no cells expressed both proteins. Following unilateral enucleation a marked reduction of calretinin-IR fibers in the contralateral side to the enucleation was found. Enucleation appeared to have no effect on the cell bodies labeled with either protein. The results suggest the anti-calretinin immunoreactivity in the superficial layer of rabbit SC contrasts starkly with that of other animals.