Correction to: Buckling of magneto-electro-hygro-thermal piezoelectric nanoplates system embedded in a visco-Pasternak medium based on nonlocal theory

Microsystem Technologies - The original version of this article unfortunately contained a mistake. Farzad Ebrahimi was not listed among the authors.     

VIS/NIR spectroscopy for non-destructive freshness assessment of Atlantic salmon (Salmo salar L.) fillets

Visible/near-infrared spectroscopy has been evaluated for use in freshness prediction and frozen-thawed classification of farmed Atlantic salmon fillets, where fresh samples were stored as whole fish in ice. A handheld interactance probe for performing rapid measurements of single fillets and an imaging spectrometer for online analysis at an industrial speed of one fillet per second, have been used. Freshness as storage days in ice is predicted with an accuracy of 2.4 days for individual fillets, whereas frozen-thawed salmon fillets are completely separated from fresh fillets. The prediction results are comparable to previous results using the Quality Index Method with trained panelists. The region between 605 and 735 nm, which excludes interference by carotenoids and water, is appropriate for both frozen-thawed classification and freshness prediction of salmon fillets. The results indicate that the spectral changes are explained mainly by oxidation of heme proteins during the freeze–thaw cycle and during chilled storage in ice.     

Development of a two-dimensional dual pendulum thrust stand for Hall thrusters

A two-dimensional dual pendulum thrust stand was developed to measure thrust vectors [axial and horizontal (transverse) direction thrusts] of a Hall thruster. A thruster with a steering mechanism is mounted on the inner pendulum, and thrust is measured from the displacement between inner and outer pendulums, by which a thermal drift effect is canceled out. Two crossover knife-edges support each pendulum arm: one is set on the other at a right angle. They enable the pendulums to swing in two directions. Thrust calibration using a pulley and weight system showed that the measurement errors were less than 0.25 mN (1.4%) in the main thrust direction and 0.09 mN (1.4%) in its transverse direction. The thrust angle of the thrust vector was measured with the stand using the thruster. Consequently, a vector deviation from the main thrust direction of +/-2.3 degrees was measured with the error of +/-0.2 degrees under the typical operating conditions for the thruster.     

Evaluation of plume characteristics of arc-heaters with various oxygen injection systems

Arc-heater plumes generated by various oxygen injection systems were investigated by laser absorption spectroscopy. Firstly, oxygen was directly injected into a high-temperature cathode-jet region through a thoriated-tungsten hollow cathode. Although number density of atomic oxygen was increased, erosion of the cathode was too severe to maintain stable discharge. Then, zirconium was used as a cathode material to reduce cathode erosion by oxidation. As a result, stable discharge was maintained for 3 h with pre-mixed argon–oxygen injection and number density of atomic oxygen was successfully increased.     

A 1.8-V operation RF CMOS transceiver for 2.4-GHz-band GFSK applications

This paper describes a single-chip RF transceiver LSI for 2.4-GHz-band Gaussian frequency shift-keying applications, such as Bluetooth. This chip uses a 0.18-/spl mu/m bulk CMOS process for lower current consumption. The LSI consists of almost all the required RF and IF building blocks: a transmit/receive antenna switch, a power amplifier, a low noise amplifier, an image rejection mixer, channel-selection filters, a limiter, a received signal strength indicator, a frequency discriminator, a voltage controlled oscillator, and a phase-locked loop synthesizer. The bandpass filter for channel selection was difficult to achieve since it operates at a low supply voltage. However, because large interference is roughly rejected at the output of the image rejection mixer and a wide-input-range bandpass filter with an optimized input bias is realized, the transceiver can operate at a supply voltage of 1.8 V. In the IF section, we adopted a circuit design using the minimum number of passive elements, resistors and capacitors, for a lower chip area of 10.2 mm/sup 2/.     

Buckling of magneto-electro-hygro-thermal piezoelectric nanoplates system embedded in a visco-Pasternak medium based on nonlocal theory

Microsystem Technologies - In this present work the critical loading of magneto-electro-viscoelastic-hygro-thermal (MEVHT) piezoelectric nanoplates embedded in a viscoelastic foundation are...     

PEDOT/PSS bending actuators for autofocus micro lens applications

This paper reports on the development of micro autofocus lens actuators using conducting polymer actuators. We propose a hydrophilic treatment for polyvinylidene difluoride (PVDF) membranes and a polyethylenedioxythiophene/poly(styrene sulfonic acid) (PEDOT/PSS) casting method for easily producing bending conducting polymer actuators with high mechanical strength.We first designed micro autofocus lens actuators using bending conducting polymer actuators, and then determined experimentally that the electrical conductivity and breaking strain of the PEDOT/PSS films could be improved by the addition of polyethylene oxide (PEO). Furthermore, we made hydrophobic PVDF membrane surfaces hydrophilic using polyethylene glycol methacrylate (PEGMA) and coated a solution of a mixture of PEDOT/PSS and PEO on the membrane surfaces to form a laminated film. We produced bending conducting polymer actuators by processing this film. Tests simulating the actuator's use in micro autofocus lenses showed the actuators to operate stably for more than a million cycles.     

Acetylacetoin synthase as a marker enzyme for detecting the 2,3-butanediol cycle

Acetylacetoin synthase (AACSase) and acetylacetoin reductase (AACRase) are representative enzymes of the 2,3-butanediol cycle. After examining their induction conditions in various bacteria, the former was induced by acetoin and the latter by glucose. All strains carrying AACSase also had AACRase, but the reverse was not true. Therefore, AACSase indicates the existence of the cycle. Acetylacetoin (AAC) accumulation or the ratio of 2,3-butanediol isomer formed also indicated the presence of the cycle in bacteria. This cycle is present in some strains and not in others even for those belonging to the same species. The cycle was not always associated with the representative 2,3-butanediol-producing bacteria or bacterial sporogenesis as reported previously.     

Amplitude-division three-electron-wave interference for observing pure phase objects having low spatial frequency

A new interferometry is presented for direct visualization of pure phase objects having low spatial frequency, such as electromagnetic microfields. A thin crystal of silicon prepared using argon ion milling is installed at the standard specimen position. This silicon crystal works as an electron beam splitter and forms diffraction spots in the back focal plane. Using the objective aperture, [000], [111] and [111] spots are selected as coherent electron sources to illuminate the specimen located at the area-selecting aperture position. The lattice image of silicon is formed below the area-selecting aperture position by decreasing the electric current of the objective lens. Three defocused images of the specimen are observed in the fluorescent screen by overexciting the first intermediate lens. We have successfully visualized equipotential lines around a latex particle charged by electron beam irradiation. The computer-simulated image was consistent with the experimental image.     

Optical frequency-domain reflectometry with a rapid wavelength-scanning superstructure-grating distributed Bragg reflector laser

Superstructure-grating distributed Bragg reflector lasers are particularly suited for optical frequency-domain reflectometry optical-coherence tomography with wide wavelength tunability and frequency agility. We report theoretical estimates of and experimental results for the data acquisition speed, the observable depth range, the resolution, and the dynamic range of an optical frequency-domain reflectometry system that uses a superstructure-grating distributed Bragg reflector laser whose wavelength can be tuned from 1533 to 1574 nm with a tuning speed of 10 micros/0.1-nm step.