This review paper focuses on interdigital electrodes-a geometric structure encountered in a wide variety of sensor and transducer designs. Physical and chemical principles behind the operation of these devices vary so much across different fields of science and technology that the common features present in all devices are often overlooked. This paper attempts to bring under one umbrella capacitive, inductive, dielectric, piezoacoustic, chemical, biological, and microelectromechanical interdigital sensors and transducers. The paper also provides historical perspective, discusses fabrication techniques, modeling of sensor parameters, application examples, and directions of future research.

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Interdigital sensors and transducers

Metal-oxide semiconductors for carbon monoxide (CO) gas sensing: A review

Application of biocatalysis and biotransformations to the synthesis of pharmaceuticals

thin ﬁlms were grown on Si and quartz substrates underdifferent oxygen ﬂow ratios OFR by radio frequency reactive magnetron sputtering. TheTauc-Lorentz dispersion method was adopted to model the optical dispersion functions of the thinﬁlms. The optical bandgap was obtained by three different methods. It was found that refractiveindex and extinction coefﬁcient decrease, and the optical bandgap has a slight blue shift withincreasing the OFR. Factors inﬂuencing the optical constants and optical bandgap are discussed.©

Optical properties of -Bi 2 O 3 thin films grown by reactive sputtering

In particular embodiments, a method includes receiving a query for particular sensor data among multiple sensor data from multiple sensors. The plurality of sensor data has been indexed according to a multi-dimensional array. One or more first ones of the dimensions include time, and one or more second ones of the dimensions include one or more pre-determined sensor-data attributes. The method includes translating the query to correspond to the indexing of the plurality of sensor data. The translated query includes one or more values for one or more of the dimensions of the multi-dimensional array. The method includes communicating the translated query to search among the plurality of sensor data according to its indexing to identify the particular sensor data.

Searching sensor data

A micromachined gas sensor based on a catalytic thick film/SnO2 thin film bilayer and a thin film heater was investigated for CO sensing. The sensor demonstrated good sensitivity and high selectivity with low power consumption. The thin film heater and the SnO2 thin film sensing layer were deposited on an Si micromachined structure having a silicon oxide–silicon nitride membrane. On the SnO2 sensing layer, a Pd-Al2O3 catalytic thick film was formed to promote CO detection with a catalyst. The sensor realized low power consumption and fast thermal response owing to small heat capacity. This fast thermal response decreased the time required to detect CO and thus decreased the time to operate the sensor. The average power consumption was less than 0.03 mW when operated every 2 min. The sensor sensitively detected CO by high-and-low periodic operation of the heater, while the sensitivity to H2, the interfering gas used, was relatively suppressed.

A micromachined gas sensor based on a catalytic thick film/SnO2 thin film bilayer and a thin film heater: Part 2: CO sensing

Microorganisms producing D-β-acetylthioisobutyric acid from methyl D-β-acetylthioisobutyrate were screened from stock cultures. The D-β-acetylthioisobutyric acid-producing ability was found in 15 strains belonging to the genera Pseudomonas, Agrobacterium, Enterobacter, Cellulomonas, Rhodococcus, Brevibacterium, and Torulopsis. A strain of Pseudomonas fluorescens, IFO 3081, was selected as the best microorganism. The cells having activity (558 units/g of dry cells) could be easily prepared by cultivation at 25°C at pH 6.6 for 24 hr in a glucose-containing medium. The D-form of methyl DL-β-acetylthioisobutyrate was selectively hydrolyzed with the cells so that D-β-acetylthioisobutyric acid (97.2% enantiomeric excess) was produced in a high yield.

Screening of Microorganisms Producing D-β-Acetylthioisobutyric Acid from Methyl DL-β-Acetylthioisobutyrate

The process conditions concerned with the production of DL-β-acetylthioisobutyric acid were investigated. Methyl DL-β-acetylthioisobutyrate as an enzyme substrate was produced from methyl methacrylate in 96.6% yield by allowing 1.0 mol of methyl methacrylate to react with 1.6 mol of thioacetic acid at 80oC for 6 h. Through the study of hydrolytic reaction of methyl DL-β-acetylthioisobutyrate with the cells of Pseudomonas putida MR-2068, it was found that D-β-acetylthioisobutyric acid having more than 98% (e.e.) optical purity was obtained when the reaction was done below pH 7.0 and below 50oC. For example, 10% (w/v) methyl DL-β-acetylthioisobutyrate in the reaction mixture was asymmetrically hydrolyzed by 0.2% (w/v) cells at 45oC at pH 7.0 for 18h to give DAT having 98.2% (e.e.) optical purity in 49.7% yield. To prevent the decompositon and racemization of D-β-acetylthioisobutyric acid in the purification process, the use of a thin-film distillation apparatus for a continuous distillation was proposed to ...

Process Conditions for Production of D-β-Acetylthioisobutyric Acid from Methyl DL-β-Acetylthioisobutyrate with the Cells of Pseudomonas putida MR-2068

http://esl.ecsdl.org/content/1/2/107.full.pdf

Hisao Ohnishi

Papers

A micromachined gas sensor based on a catalytic thick film/SnO2 thin film bilayer and a thin film heater: Part 2: CO sensing

Screening of Microorganisms Producing D-β-Acetylthioisobutyric Acid from Methyl DL-β-Acetylthioisobutyrate

Process Conditions for Production of D-β-Acetylthioisobutyric Acid from Methyl DL-β-Acetylthioisobutyrate with the Cells of Pseudomonas putida MR-2068

Highly Selective NO Detection Using Bi2 O 3 ‐ Based Materials

A Newly Isolated Microorganism Producing D-β-Acetylthioisobutyric Acid from Methyl DL-β-Acetylthioisobutyrate