bluuebunny/crossref_metadata_2025 huggingface dataset:
Generic status of Quisqualis (Combretaceae), with notes on the taxonomy and distribution of Q. parviflora
Authors: Jordaan M. , Van Wyk A. E. , Maurin O.
Published: March 2014

The taxonomic status of Quisqualis L., a genus closely related to and sometimes considered congeneric with Combretum Loefl., is discussed. The genus Quisqualis is maintained to accommodate selected African, Indian, Asian and Malesian species (including Q. indica L. and Q. parviflora Sond.). Diagnostic characters for Quisqualis include: leaves with abundant subepidermal crystalliferous idioblasts, each containing a large druse of calcium oxalate; leaves, stems and flowers with stalked glands but no scales; persistent petiole bases that develop into curved spines; petals well developed; hypanthium tubular or cylindrical, usually longer than 20 mm; stamens and style not or scarcely exserted; style adnate to hypanthium for more than half its length. Quisqualis shares a number of morphological similarities with Combretum Loefl. subgen. Cacoucia (Aubl.) Exell Stace sect. Poivrea (Comm. ex DC.) G.Don. Some species of Combretaceae from West, West Central and East Africa have the style adnate to the upper hypanthium and display features reminiscent of both Quisqualis and Combretum. These species also have characters of their own and in the past were placed in different sections under Combretum. It is suggested that at least some of these species may be best classified in genera distinct from Combretum and Quisqualis, one of which is Campylogyne Hemsley. Combretum s.str. is defined on the basis of a combination of characters and includes species of which the upper hypanthium is variable in shape, but when tubular or cylindrical, then always shorter than 20 mm. Other diagnostic characters include: stamens exserted well beyond petals; style exserted and free, but when shortly adnate to upper hypanthium (only at the base or for a short distance), then stamens long-exserted. It is suggested that different pollination strategies have developed independently in the Combretum–Quisqualis clade, resulting in convergent morphological trends in floral morphology. These homoplasious similarities in floral morphology are at the root of the difficulties experienced to demarcate genera. An alternative classification is provided for those preferring to include the southern African Quisqualis parviflora under Combretum s. l. For this purpose, a new combination and name, Combretum sylvicola O.Maurin is provided. Quisqualis parviflora is confined to the Eastern Cape and KwaZulu-Natal coastal regions and does not extend beyond this area as has been claimed by some. A comparative table to differentiate among four groups in Quisqualis and Combretum in Africa, as well as a photo of a herbarium specimen and a distribution map of Quisqualis parviflora, are provided.
Asteraceae
Authors: Herman P. P. J. , Swelankomo N.
Published: March 2014

Vernonia (tribe Vernonieae) and related genera in southern Africa: updates and corrections.
Apocynaceae
Authors: Bester S. P. , Joubert L.
Published: March 2014

Distribution of Cryptolepis delagoensis (Periplocoideae–Cryptolepideae), a subcontinental southern African endemic and selection of a neotype.
Nyctaginaceae
Authors: Struwig M. , Siebert S. J. , Klaassen E. S.
Published: March 2014

Notes on Commicarpus in southern Africa, including a new record for Namibia.
Vitaceae - A new and an overlooked record of Cyphostemma in Angola
Authors: De Sousa F. , Figueiredo E. , Smith G. F.
Published: March 2014

A new and an overlooked record of Cyphostemma in Angola.
Iridaceae
Authors: Manning J. C. , Goldblatt P.
Published: March 2014

Gladiolus diluvialis (Crocoideae), a replacement name for the illegitimate homonym G. halophilus.
Hyacinthaceae
Authors: Manning J. C. , Goldblatt P.
Published: March 2014

New combinations in Ledebouria.
Fabaceae
Authors: Moteetee A. N. , Van Wyk B. E.
Published: March 2014

Ophrestia oblongifolia (Phaseoleae) in southern Africa.
Cyperaceae
Authors: Archer C. , Balkwill K.
Published: March 2014

Identity and typification of Carex cognata and status of C. drakensbergensis.
Colchicaceae
Authors: Maroyi A.
Published: March 2014

First record of Gloriosa sessiliflora in Angola.
Hyacinthaceae
Authors: Manning J. C. , Goldblatt P.
Published: March 2014

Nomenclatural corrections in sub-Saharan Africa, predominantly subfam. Urgineoideae.
Asteraceae
Authors: Boon R. , Glen H. F.
Published: March 2014

Distephanus (Asteraceae: Vernonieae): a new combination and a new record for southern Africa.
Notes on naturalised plants
Authors: Cheek M. D.
Published: March 2014

Petiveria alliacea in KwaZulu-Natal, South Africa.
Hyacinthaceae
Authors: Manning J. C. , Goldblatt P.
Published: March 2014

Five new combinations in Ornithogaloideae in southern Africa and a recommendation for optional combinations in the subfamily.
A new infrageneric classification for Mesembryanthemum (Aizoaceae: Mesembryanthemoideae)
Authors: Klak C. , Bruyns P. V.
Published: March 2014

We present a new infrageneric classification for Mesembryanthemum L. (Aizoaceae: Mesembryanthemoideae), based on a phylogeny of the genus published in 2007. We re-affirm that a broad generic circumscription for Mesembryanthemum (including all 103 species of the Mesembryanthemoideae) is the only group in the subfamily that can be recognized unambiguously by synapomorphies. We divide Mesembryanthemum into five subgenera, of which two are new: M. subg. Mesembryanthemum, M. subg. Cryophytum (N.E. Br.) Bittrich, M. subg. Opophytum (N.E. Br.) Bittrich, M. subg. Phyllobolus (N.E. Br.) Klak and M. subg. Volkeranthus (Gerbaulet) Klak. Furthermore, we recognize five sections in subg. Mesembryanthemum, six sections in subg. Phyllobolus and two sections in M. subg. Cryophytum. Descriptions and keys to all infrageneric taxa are provided.
Towards the identification of molecular constituents associated with the surfaces of isoprene-derived secondary organic aerosol (SOA) particles
Authors: Ebben C. J. , Strick B. F. , Upshur M. A. , Chase H. M. , Achtyl J. L. , Thomson R. J. , Geiger F. M.
Published: March 2014

Abstract. Secondary organic aerosol (SOA) particle formation ranks among the least understood chemical processes in the atmosphere, rooted in part in the lack of knowledge about chemical composition and structure at the particle surface, and little availability of reference compounds needed for benchmarking and chemical identification in pure and homogenous form. Here, we synthesize and characterize SOA particle constituents consisting of the isoprene oxidation products α-, δ-, and cis- and trans-β-IEPOX (isoprene epoxide), as well as syn- and anti-2-methyltetraol. Paying particular attention to their phase state (condensed vs. vapor), we carry out a surface-specific and orientationally selective chemical analysis by vibrational sum frequency generation (SFG) spectroscopy of these compounds in contact with a fused silica window. Comparison to the vibrational SFG spectra of synthetic isoprene-derived SOA particle material prepared at the Harvard Environmental Chamber yields a plausible match with trans-β-IEPOX, suggesting it is an abundant species on their surfaces, while the other species studied here, if present, appear to be SFG inactive and thus likely to be localized in a centrosymmetric environment, e.g., the particle bulk. No match is found for authentic SOA particle material collected at the site of the Amazonian Aerosol Characterization Experiment (AMAZE-08) with the surface SFG spectra of the compounds surveyed here, yet we cannot rule out this mismatch being attributable to differences in molecular orientation. The implications of our findings for SOA formation are discussed in the context of condensational particle growth and reactivity.
Determining the focal mechanisms of the events in the Carpathian region of Ukraine
Authors: Pavlova A. , Hrytsai O. , Malytskyy D.
Published: March 2014

Abstract. The modification of the matrix method for constructing the displacement field on the free surface of an anisotropic layered medium is presented. The source of seismic waves is modelled by a randomly oriented force and seismic tensor. A trial and error method is presented for solving the inverse problem of determining parameters of the earthquake source. A number of analytical and numerical approaches to determining the earthquake source parameters, based on the direct problem solutions, are proposed. The focal mechanisms for the events in the Carpathian region of Ukraine are determined by the graphical method. The theory of determinating the angles of orientation of the fault plane and the earthquake's focal mechanism is presented. The focal mechanisms obtained by two different methods are compared.
CALIBRATION OF PANORAMIC CAMERAS WITH CODED TARGETS AND A 3D CALIBRATION FIELD
Authors: Tommaselli A. M. G. , Marcato Jr. J. , Moraes M. V. A. , Silva S. L. A. , Artero A. O.
Published: March 2014

Abstract. The aim of this paper is to present results achieved with a 3D terrestrial calibration field, designed for calibrating digital cameras and omnidirectional sensors. This terrestrial calibration field is composed of 139 ARUCO coded targets. Some experiments were performed using a Nikon D3100 digital camera with 8mm Samyang Bower fisheye lens. The camera was calibrated in this terrestrial test field using a conventional bundle adjustment with the Collinearity and mathematical models specially designed for fisheye lenses. The CMC software (Calibration with Multiple Cameras), developed in-house, was used for the calibration trials. This software was modified to use fisheye models to which the Conrady-Brown distortion equations were added. The target identification and image measurements of its four corners were performed automatically with a public software. Several experiments were performed with 16 images and the results were presented and compared. Besides the calibration of fish-eye cameras, the field was designed for calibration of a catadrioptic system and brief informations on the calibration of this unit will be provided in the paper.
UAS Mapping as an alternative for land surveying techniques?
Authors: Devriendt L. , Bonne J.
Published: March 2014

Abstract. Can a UAS mapping technique compete with standard surveying techniques? Since the boom in different RPAS (remotely piloted air system), UAV (unmanned aerial vehicle), or UAS (unmanned aerial system), this is one of the crucial questions when it comes to UAS mappings. Not the looks and feels are important but the reliability, ease-to-use, and accuracy that you get with a system based on hardware and corresponding software. This was also one of the issues that the Dutch Land Registry asked a few months ago aimed at achieving an effective and usable system for updating property boundaries in new-build districts. Orbit GT gave them a ready-made answer: a definitive outcome based on years of research and development in UAS mapping technology and software.
Weightbearing CBCT, MDCT, and 2D imaging dosimetry of the foot and ankle
Authors: Ludlow John B. , Ivanovic Marija
Published: March 2014

Aims: This study compares effective doses associated with 2D lateral, oblique, and AP radiographs with 3D MDCT and Cone Beam CT images of the foot and ankle. Methods: An anthropomorphic phantom of the foot and ankle was constructed from an adult human skeleton and soft tissue equivalent material. Optical stimulated dosimeters were placed at 21 locations within and on tissues and anatomy of interest. Effective dose was calculated following 2007 ICRP recommendations. Three projections were exposed to simulate conventional 2D imaging. Standard and optimized dose MDCT scans were exposed to simulate typical CT options. Ten, 20, and 30cm fields of view, 100 and 120kVp and 4.5 and 6.8mAs exposures were tested using a PedCAT® CBCT device designed for weightbearing imaging. Dose was calculated for an adult as well as for a 5 and 10-year-old child to assess the impact of age on risk estimation. Results: Standard adult effective doses for single foot imaging were 0.6µSv for 2D, 3.8µSv for CBCT, and 25µSv for MDCT (p = 0.0013). Dose differed significantly with age (p = 0.0185). For a 5-year-old, doses rise to 0.8µSv for 2D, 18µSv for CBCT, and 200µSv for MDCT. Small and medium CBCT fields produced adult doses of 2.3 mSv and 0.9 mSv respectively. Conclusions: The effective dose for small FOV CBCT or conventional 2D series examinations is comparable to a few hours of equivalent background dose. Such doses are negligible; therefore, the dose of radiation should not be a concern when considering the use of CBCT imaging for foot/ankle examination.
Interspecific Competition between Microcystis aeruginosa and Anabaena flos-aquae from Taihu Lake, China
Authors: Zhang Xue-Wei , Fu Jie , Song Shuang , Zhang Ping , Yang Xian-Hui , Zhang Li-Rong , Luo Yin , Liu Chang-Hong , Zhu Hai-Liang
Published: March 2014

Microcystis and Anabaena are the main cyanobacteria that cause cyanobacterial blooms in Taihu Lake, China. The mechanism of population competition between M. aeruginosa and A. flos-aquae was studied by co-cultivation in the laboratory. The growth of M. aeruginosa was inhibited, while the growth of A. flos-aquae was promoted. The degree of inhibition or promotion was related to the ratio of the initial cell densities. Both cell-free filtrates of A. flos-aquae and co-culture inhibited M. aeruginosa growth, while both cell-free filtrates of M. aeruginosa and co-culture promoted A. flos-aquae growth. Analysis of the cell-free filtrate by gas chromatography-mass spectrometry indicated that M. aeruginosa and A. flos-aquae may secrete some extracellular allelochemicals that inhibit (promote) the growth of M. aeruginosa (A. flos-aquae) in co-culture. These compounds included sulfur compounds, naphthalene derivatives, cedrene derivatives, quinones, phenol derivatives, diphenyl derivatives, anthracene derivatives, and phthalate esters. This study can help to understand the characteristics of M. aeruginosa and A. flos-aquae and to provide new concepts for the control of cyanobacterial blooms in Taihu Lake.
Improved Ant Colony Optimization for Seafood Product Delivery Routing Problem
Authors: Yao Baozhen , Hu Ping , Zhang Mingheng , Tian Xiaomei
Published: March 2014

This paper deals with a real-life vehicle delivery routing problem, which is a seafood product delivery routing problem. Considering the features of the seafood product delivery routing problem, this paper formulated this problem as a multi-depot open vehicle routing problem. Since the multi-depot open vehicle routing problem is a very complex problem, a method is used to reduce the complexity of the problem by changing the multi-depot open vehicle routing problem into an open vehicle routing problem with a dummy central depot in this paper. Then, ant colony optimization is used to solve the problem. To improve the performance of the algorithm, crossover operation and some adaptive strategies are used. Finally, the computational results for the benchmark problems of the multi-depot vehicle routing problem indicate that the proposed ant colony optimization is an effective method to solve the multi-depot vehicle routing problem. Furthermore, the computation results of the seafood product delivery problem from Dalian, China also suggest that the proposed ant colony optimization is feasible to solve the seafood product delivery routing problem.
A proteomic chronology of gene expression through the cell cycle in human myeloid leukemia cells
Authors: Ly Tony , Ahmad Yasmeen , Shlien Adam , Soroka Dominique , Mills Allie , Emanuele Michael J , Stratton Michael R , Lamond Angus I
Published: March 2014

Technological advances have enabled the analysis of cellular protein and RNA levels with unprecedented depth and sensitivity, allowing for an unbiased re-evaluation of gene regulation during fundamental biological processes. Here, we have chronicled the dynamics of protein and mRNA expression levels across a minimally perturbed cell cycle in human myeloid leukemia cells using centrifugal elutriation combined with mass spectrometry-based proteomics and RNA-Seq, avoiding artificial synchronization procedures. We identify myeloid-specific gene expression and variations in protein abundance, isoform expression and phosphorylation at different cell cycle stages. We dissect the relationship between protein and mRNA levels for both bulk gene expression and for over ∼6000 genes individually across the cell cycle, revealing complex, gene-specific patterns. This data set, one of the deepest surveys to date of gene expression in human cells, is presented in an online, searchable database, the Encyclopedia of Proteome Dynamics (http://www.peptracker.com/epd/).
Study on processing step uniformity tuning during FET fabrication and sensor wafer response as a function of chuck temperature adjustment
Authors: Milenin Alexey P. , Boullart Werner , Quli Farhat , Wen Youxian
Published: March 2014

The effect of chuck temperature adjustment on critical dimension uniformity was studied for the shallow trench isolation etch process by introducing a temperature gradient in a multi-temperature-zone electrostatic chuck. It is shown that the initial radial critical dimension non-uniformity can be improved by a gradual temperature adjustment of the electrostatic chuck and results in the target specification values of uniformity, 3σ ≤ 1.5 nm, for a critical dimension of about 35 nm. Both temperature and RF sensor wafers were used to analyze the impact of an electrostatic chuck temperature gradient on process uniformity by utilizing their unique in situ spatial and temporal mapping capabilities. Thus, the across-wafer thermal sensitivity of the critical dimension was estimated for dense structures: a temperature change of 1 °C leads to a critical dimension change of ∼0.7 nm. The RF sensor wafer was also shown to have a clear response of RF current uniformity to the electrostatic chuck temperature gradient that suggests there could be other phenomena affecting critical dimension uniformity besides temperature itself. The pure temperature contribution to critical dimension change was found to be less than 0.3 nm/°C for the temperature range studied. Finally, a possible mechanism of critical dimension tuning is discussed and an assessment of each separate etch step’s sensitivity to the electrostatic chuck temperature gradient is performed.
Selective etch of poly(methyl methacrylate) in block copolymer based on control of ion energy and design of gas chemistry for directed self assembly lithography
Authors: Yamamoto Hiroshi , Imamura Tsubasa , Omura Mitsuhiro , Sakai Itsuko , Hayashi Hisataka
Published: March 2014

The selective etching of poly(methyl methacrylate) (PMMA) in a block copolymer was studied with a focus on the material structures of polystyrene (PS) and PMMA. Based on our predictions, we investigated the effect of ion bombardment and designed a carbon-containing gas plasma to improve selectivity. The etching characteristics of the carbon-containing gas plasma on the polymers were examined. Highly selective etching of PMMA to PS was achieved using the carbon-containing gas plasma. The carbon species in the plasma increased with increasing carbon-containing gas ratio and suppressed the PS etch rate drastically. The CO plasma process was successfully applied to a dry development process for directed-self assembly lithography.
Line-edge roughness increase due to wiggling enhanced by initial pattern waviness
Authors: Kofuji Naoyuki , Negishi Nobuyuki , Ishimura Hiroaki , Nishida Toshiaki , Kobayashi Hitoshi
Published: March 2014

To clarify whether pattern waviness due to line-edge-roughness enhances wiggling, distortion of straight and wavy patterns was numerically analyzed by the three-dimensional (3D) elastic finite element method. Wiggling occurs only in wavy patterns but not in straight patterns at a stress or aspect ratio much lower than their buckling thresholds. More severe wiggling occurs when the wavelength of initial waviness approaches a value that is 3.3 times the pattern height. These phenomena were experimentally confirmed in the etching of amorphous carbon with a SiON mask. We consider that precise etching without wiggling is achieved by the elimination of the original line-edge roughness and the reduction in mechanical stress in an underlying film to which the pattern is transferred.
Nonequilibrium green function simulations of graphene-nanoribbon resonant-tunneling transistors
Authors: Mori Nobuya , Edagawa Takuya , Kamakura Yoshinari , Eaves Laurence
Published: March 2014

We have performed nonequilibrium Green function simulations on the transport characteristics in ultra-small graphene nanoribbon resonant-tunneling transistors (RTTs). For an ultra-narrow nanoribbon transistor, the current–voltage characteristics resemble those observed in large-size graphene-based RTTs. For a wider nanoribbon transistor, we find that two types of structure due to inter-subband transitions appear in addition to the main peak: one originates from the resonance at k

x
= 0, while the other is due to resonance at finite k

x
.
Analysis of SAW Scattering from Metallic Gratings
Authors: Koshiba Masanori , Iikawa Rika , Hasegawa Koji
Published: March 2014

A numerical approach based on the finite-element method is presented for the analysis of Rayleigh-wave scattering from reflective gratings on a piezoelectric substrate. To treat a large periodic structure in which a repetition of complicated components arises, the substructure method has been introduced. As a result, the mutual interaction between surface waves and bulk waves is automatically taken into account over the entire discontinuity region. To show the validity and usefulness of this approach, examples are computed for various metallic gratings on a 128° Y-X LiNbO3 substrate. The computed results agree approximately with the earlier experimental results.
Characteristics of Bolt-Clamped Langevin Type Ultrasonic Transducer with Square Radiating Surface
Authors: Yamamori Haruo , Ito Toshiharu , Ohya Kanji , Banno Hisao
Published: March 2014

A bolt-clamped Langevin type ultrasonic transducer having a square radiating surface was studied in relationship between amplitude distribution on the radiating surface and front-block size. A chamfered transducer with a 45 mm square surface showed uniform vibration amplitude distribution on its radiating surface. An immersible ultrasonic cleaner installed with optimized transducers was verified in terms of sound pressure in water.
Quick Response in Rotation of Ultrasonic Motor
Authors: Sugihara Miho , Kishi Toru , Inaba Ritsuo
Published: March 2014

Very quick response of less than 1 msec rotation is obtained with the development of a small-sized 17 mm diameter ultrasonic motor. This motor is driven by the mechanical vibration excited on the disk plate by piezoelectric ceramics.The observed response time in starting is 0.57 msec and the time in stopping is 0.33 msec at the no-load revolution speed of 700 rpm. These results coincide well with the calculation of the response time based on the experimental results between revolution speed and torque.
A Study on Nondestructive Inspection of Long-Term Degradation in Electric Power Plant Materials by Ultrasonics
Authors: Imaeda Hiromasa
Published: March 2014

An application of ultrasonics to diagnose material degradation by the long-term operation of power plants was discussed. The simulation of degradation caused by long-term operation was made by applying several heat treatments to alloy steels. The relationship between ultrasonic characteristics and microstructure of the plant steels was discussed. Ultrasonic measurement was recognized as a potential means for the diagnosis of degradation.
Temperature Dependences of The Nonlinearity Parameter of Liquid-Like Media
Authors: Asahina Tetsuya , Endoh Nobuyuki , Demura Kazuhiko , Niino Toshiki , Tomita Masatoshi
Published: March 2014

The nonlinearity parameters B/A of liquid and liquid-like media such as soft tissue were measured by the thermodynamic method. The temperature dependences of B/A were obtained from 20 to 40°C. We also got B/A of water mixed with methanol, and varied the methanol mixture weight ratio from 10 to 75%. The B/A of water, methanol mixture and soft tissues are approximately proportional to the temperature. However, that of the methanol mixture did not change linearly with the methanol mixture ratio; it appeared to be constant at the ratio from 0 to 25% and from 75 to 100%, but changed rapidly at the ratio of about 50%.
Ultrasonic Measurement of Lipid Bilayer Transition in The Presence of Melittin
Authors: Hirose Norimitsu , Yamamoto Kazunori , Mitaku Shigeki
Published: March 2014

Ultrasonic relaxation was measured for suspensions of sonicated dimyristoyl phosphatidylcholine (DMPC) vesicles in the presence of melittin, the lipid/melittin ratio being 100/1. The results showed that a DMPC/melittin suspension at pH 5 was characterized by much larger relaxation strength and relaxation time than a pure DMPC vesicle suspension. The relaxation phenomenon indicated anomalous enhancement in the vicinity of a gel-to-liquid crystal transition point, which was the characteric feature of a critical phenomenon. The transition temperature increased by about 1°C with the addition of melittin.
Photoacoustic Dispersion Measurements by Pseudo Random Modulation at Low Temperature
Authors: Kashiwada Tomonori , Nakahira Shin'ichi , Kojima Seiji , Suzuki Tetsuro
Published: March 2014

The glass transition of glycerol was investigated by photoacoustic measurements, and the frequency dependence of photoacoustic signals was obtained by both a single frequency and the M sequence modulation. The temperature dependence of the photoacoustic amplitude and phase were measured in the neighborhood of a glass transition temperature. A shift of the glass transition temperatures with the modulation frequency was obtained.
Evaluation of Amorphous Semiconductors by Photoacoustic Spectroscopy Using a Transparent Transducer
Authors: Kanemitsu Yoshihiko , Nabeta Hiroyuki
Published: March 2014

Optical properties of amorphous semiconductors were studied by photoacoustic (PA) spectroscopy using a transparent LiNbO3 transducer. The PA signal detected at the light-irradiated front surface of the sample has a large value and a good signal-to-noise ratio compared with that at the back surface. It is demonstrated that a light-induced change in the PA signal at the surface in thick samples and PA spectra of multilayered semiconductor films can be obtained using the transparent transducer.
An Acoustic Imaging System Using Phase Conjugate Waves
Authors: Ohno Masahiro
Published: March 2014

A scanning acoustic imaging system at 50 MHz using phase conjugate waves is proposed. The phase-shift-undoing property of the phase conjugation was used to remove the wave front distortion of the sound beam. Obtained images showed the attenuation property of the samples and were free from the influence of surface roughness.
Analysis of Magnetostatic Wave Transducers by a New Equivalent Circuit Model
Authors: Koike Takuro
Published: March 2014

A new equivalent circuit analysis for magnetostatic wave (MSW) devices, which is constructed in a different way from that given previously by the author, is discussed. As before, a magnetomotive force F, a magnetostatic current l, and a magnetostatic characteristic impedance z
0 are so defined that the power carried by the MSW through the cross-section of the sample is correctly described. The validity of the model is examined by calculating the frequency dependence of radiation admittance of parallel-strip (grating) transducers.
New Research Fields of Ultrasonic Electronics and Underwater Acoustics
Authors: Kuyama Tamio
Published: March 2014

Recent developments in the reduction of underwater noise radiated from a surface ship and a submarine are presented. The importance of the same signal processing architecture is indicated for astrophysics.
High Performance Ultrasonic Transducers Employing ZnO/Pyrex-glass Diaphragm Structure on a Si Substrate
Authors: Yamada Yoshihisa , Hashimoto Ken-ya , Rajendran Velayutham , Yamaguchi Masatsune
Published: March 2014

The paper describes the development of high performance underwater ultrasonic transducers employing ZnO/Pyrex-glass composite diaphragm structure on a Si substrate. It is shown that the transducer successfully radiates and detects ultrasonics at the fundamental frequency of 155 MHz with a relative -3 dB band width of 11.1% and a minimum transduction loss of 4.3 dB, both of which are in good agreement with theoretical prediction. The possibility of the application of the transducer to sensor devices is described for the measurement of ultrasonic wave velocity in liquid.
A Method of Measuring the Vibration Level Dependence of Impedance-Type Equivalent Circuit Constants
Authors: Hirose Seiji , Yamayoshi Yasuhiro , Taga Masashi , Shimizu Hiroshi
Published: March 2014

In piezoelectric transducers with high electromechanical coupling and finite dielectric loss angle, the mechanical quality factor of the transducer resonating under the short-circuit condition of the electric terminal is usually lower than that under the open-circuit condition. This fact is well explained by the impedance-type improved equivalent circuit including the effect of dielectric loss. This circuit is available for design of high power ultrasonic devices. A method of measuring the vibration level dependence of the impedance-type circuit constants is described and some experimental results are shown.
Free-Field Voltage Sensitivities of Flexible Piezoelectric Rubbers
Authors: Hasegawa Akio , Kikuchi Toshiaki , Yoshii Satoshi
Published: March 2014

Conventional PZT ceramics are hard materials. This hardness exhibits noticeable resonances and causes a narrow bandwidth. Flexible piezoelectric rubbers are very promising piezoelectric materials for wide bandwidth applications because of their lower Q and lower dielectric constant than those of PZT ceramics. The free-field voltage sensitivities are measured over the frequency ranges 20–150 kHz and 100–1000 kHz, and the results of these measurements are compared with those obtained from PZT and anisotropic (Pb, Ca)TiO3 ceramics. It is clarified that piezoelectric rubbers as well as (Pb, Ca)TiO3 are very useful for underwater hydrophone applications over wider frequency ranges.
Rapid Tracking of Resonance and Antiresonance of a Piezoelectric Reasonator: A Phase-Locked Loop for Capacitive Loads
Authors: Hayashi Shigeo , Sasaki Yukihiko
Published: March 2014

A simple phase detector/loop filter is devised which makes possible the tracking of resonances and antiresonances at which the sign of the phase angle remains positive. Successful lock-capture is observed at fundamental and higher-order modes of a PZT resonator for various values of initial frequency. Depending on Q-factor, final frequency values are affected more or less by the initial values. The overall lock-capture behavior is accounted for largely by computer simulations in which the VCO is described by a first-order delay function.
Evaluation of Metal Films Utilizing the Cross Effect of Interaction Spectra of Surface Plasmons with Surface Acoustic Waves
Authors: Sun Xiaochun , Shiokawa Showko , Matsui Yoshikazu
Published: March 2014

Utilizing the interaction spectra of surface plasmons with surface acoustic waves, the properties of three types of surface plasmon active layers: Ag, Au and Cu films and the oxidization effect of Ag film were studied. The “cross effect”, which results from the superposition of two resonant components of surface plasmons in the first order diffracted spectra shows high sensitivity to changes in the dielectric properties of metals and demonstrates the potential for evaluating metal films by utilizing this physical phenomenon.
Second Harmonic Generation of Surface Acoustic Waves from a Dot Array
Authors: Nakagawa Yasuhiko , Koyama Akihiro , Nakayama Hideki
Published: March 2014

This paper surveys the generation of a second harmonic component of surface acoustic waves from a dot array which replaces a surface acoustic waveguide on the piezoelectric substrate. The direction of propagation for second harmonic can be controlled by frequency and periodic length of dots.
Elastic Constants and Temperature Coefficients of LiTaO3 for SAW Application
Authors: Murota Masao , Shimizu Yasutaka
Published: March 2014

A method to obtain material constants for SAW application is proposed and new elastic constants and temperature coefficients of LiTaO3 are displayed. They were numerically calculated from experimental SAW velocities using the method of least squares and n-th dimension Newton's iterative method. Theoretical values with the new constants are in very good agreement with experimental data on X, Y, and Z-cuts at all temperatures. These constants should be practical for theoretical prediction.
Precise Fabrication Technique of UHF SAW Al Electrodes and Leaky SAW Propagation Characteristics on 36° Y-X LiTaO3
Authors: Hosaka Norio , Yuhara Akitsuna , Kobayashi Takao , Watanabe Hitoshi , Yamada Jun
Published: March 2014

Fabrication technique and leaky SAW (LSAW) propagation characteristics for GHz SAW filters are studied. Dyed photoresist and RIE are employed for fine dimension control of Al electrodes in these SAW filters and the deviation of the pattern width is remarkably decreased, for example, to a value of 110 nm (3σ) in a 0.6 µm line/space pattern. LSAW velocity dispersion and propagation loss on 36° Y-X LiTaO3 are also experimentally investigated. The results suggest requirement of some improvements in the substrates, the filter design and the fabrication technique.
Wide Bandwidth Low Loss Filters Using Piezoelectric Leaky SAW Unidirectional Transducers with Floating Electrodes
Authors: Yamanouchi Kazuhiko , Takeuchi Masao , Meguro Toshiyasu , Doi Kenji , Murata Kenji
Published: March 2014

A new configuration of SAW floating electrode unidirectional transducer (FEUDT) previously proposed is theoretically investigated using Green's function method and is also experimentally studied. The improved FEUDTs provide easier fabrication, higher operating frequency, and better characteristics for a piezoelectric leaky SAW with a low propagation attenuation and a high electromechanical coupling coefficient. Experimental filters consisting of FEUDTs and narrow gap FEUDTs (NGFEUDT) with minimum electrode width 2.5 µm on a 41° Y
X LiNbO3 substrate show the low insertion loss of 2.6 dB at 360 MHz and 2.8 dB at 700 MHz, respectively.
Studies on Ultrasonic Butt Welding System Using A Large Capacity Static Induction Thyristor Power Amplifier
Authors: Tsujino Jiromaru , Ueoka Tetsugi , Suzaki Yukihide , Uchida Kazutoshi , Watanabe Ichiro , Andoh Akikazu
Published: March 2014

Ultrasonic butt welding using one powerful 15 kHz vibration source and a large capacity power amplifier is studied. The vibration source designed has eight 15 kHz boltclamped Langevin type PZT transducers with 150% capacity of a 19 kHz transducer and are driven by a newly designed 50 kW or 100 kW solid-state power amplifier. Vibration characteristics under large vibration amplitude are measured. For good welding results, a matching circuit appropriate for the welding load is required to improve the power factor of the system. Welding specimens of 6 mm thick aluminum plate are successfully joined end to end.
The Effect of Crosslinks on Ultrasonic Properties in Glassy Epoxy Resin
Authors: Matsukawa Mami , Nagai Isao , Tanaka Toshimitsu , Kondo Haruki
Published: March 2014

Ultrasonic properties in epoxy resins cured with three different curing agents, methylnadic anhydride (MNA) and two kinds of aliphatic diamine, were investigated in the MHz region. The apparent moduli calculated from ultrasonic velocities and longitudinal absorptions in glassy resins show a decrease of elasticity with crosslinking in the MNA cured system, whereas the elasticity of rubbery resins has been reported to be proportional to the amount of crosslinks. The elasticity in glassy resins depends on the glass transition process, and we observed a similar phenomenon in the diamine system cured at high temperature.
Surface Curvature Effect on Optical Beam Deflection Signal from a Single Microparticulate Sample
Authors: Wu Jiaqi , Kitamori Takehiko , Sawada Tsuguo
Published: March 2014

A three-dimensional theoretical treatment was established for the photothermal deflection signal from a two-layered single microparticulate sample. The proprieties of the analytical results were confirmed by comparing the theoretical values of the frequency characteristics with the experimental ones. This theory suggests that the microparticle surface curvature localizes the temperature field and enhances its gradient, resulting in unique size dependences of sensitivity for the beam deflection signal, i.e. more sensitivity for smaller microparticles.
Introduction to Japan of the Technology of the Echo Sounder and Active Sonar Developed by Professor Paul Langevin
Authors: Nirei Kiyoshi
Published: March 2014

From my position related to the technology of marine acoustics, I have been studying how the achievements of Professor Paul Langevin were introduced to Japan. I would first like to provide a little background to this, and then ask for some of your opinions.
Ultrasonic Study of Gelation and Vitrification in Curing Process of Allyl-Oligomer
Authors: Okabe Hirotaka , Takashima Wataru , Taki Seiji , Matsushige Kazumi
Published: March 2014

An automatic ultrasonic velocity measuring system was utilized to investigate an isothermal curing process of allyl-ester, a new thermosetting resin composed of an allyl-oligomer and a curing agent. The logarithmic curing time vs sound velocity curves showed apparent bends at curing temperatures below 140 °C, while a monotonous relation above 150 °C. The analysis based on a reaction rate equation suggested that such ultrasonic behavior resulted from the different mechanism of gelation and/or vitrification, which became dominant depending on the curing temperature.
Measurement Method for Acoustic Nonlinearity Parameter of Small Volume Samples Using a Focused Gaussian Beam
Authors: Saito Shigemi
Published: March 2014

The nonlinear distortion of the sound in a focused beam is accentuated at the focus. Utilizing this phenomenon, a measurement method for the acoustic nonlinearity parameter of a small-volume liquid sample is presented. The
nonlinearity parameter is derived through comparison between experimental and theoretical values of a newly defined variable R
s, which describes the influence of the sample on the amplitudes and phases of the fundamental and second harmonic components of the transmitting sound. The present method is especially useful for lossy samples.
Development of Scanning Photoacoustic Microscope
Authors: Tokunaga Yoshiaki , Minamide Akiyuki
Published: March 2014

The paper describes the advantages of our scanning photoacoustic microscope (SPAM) as a nondestructive equipment for evaluating and imaging surface flaws and subsurface cracks in advanced materials. Hardware and software of the SPAM were discussed. It was found that surface flaws and subsurface drill holes in epoxy resin well analyzed by using the SPAM. This microscope was also effective in imaging the distributions of carbon fiber fluxes in a carbon fiber reinforced plastic.
Influence of Piezoelectric and Pyroelectric Effects on Signal of PAS Using a Transparent Transducer
Authors: Horita Susumu , Saikawa Takeshi , Hata Tomonobu
Published: March 2014

Photoacoustic spectroscopy (PAS) using a transparent transducer LiNbO3 detects not only thermoelastic waves but also thermal waves because LiNbO3 has pyroelectricity as well as piezoelectricity. Then, we investigated the influence of the piezoelectric and pyroelectric effects on PA signal theoretically and experimentally, using three kinds of transparent transducers, Y-, 128° rotated Y- and Z-cut LiNbO3's. It was found that the pyroelectric effect predominates over the signal of the transducer more than the piezoelectric effect when the incident direction of an excitation light was toward to the transducer.
Optical and Thermal Evaluation of Semiconductor by Differential Photothermal Deflection Spectroscopy
Authors: Hata Tomonobu , Ishimaru Masahiko , Horita Susumu
Published: March 2014

This paper concerns the experimental evaluation of optical and thermal properties of a semiconductor by our newly proposed differential PDS method. A thermal conductivity and a large absorption coefficient are determined from the saturation region and the linear region of the signal, respectively. The thermal conductivity of Si is evaluated to be 1.42 [W/cm·K] which is almost identical with a handbook data 1.48 [W/cm·K] and the maximum absorption coefficient obtained by differential PDS is one order larger than that obtained by conventional PDS.
Photoacoustic Flowcell Using Acoustic Resonance
Authors: Tabuchi Yukito , Matsunaka Toshiyuki
Published: March 2014

A resonant photoacoustic flowcell with a sensitivity of 50 µV-cm/ABS for incident light with a peak power of 90 mW was constructed. The feasible range of measurements with this type of cell was from less than 0.01 ABS/cm to more than 10 ABS/cm. This cell is suitable as a monitor of photoabsorptive materials with a strong scattering ability in liquid.
Optimum Electrode Design for Effective Excitation of the Edge Mode by Taking Account of Its Electric Potential Distribution
Authors: Watanabe Hiroshi , Saito Hironobu , Shimizu Hiroshi
Published: March 2014

Effective excitation of the edge mode in a thin piezoelectric ceramic strip is studied on the basis of its electric potential distribution, and a method of optimum electrode design for strongly exciting the mode is proposed. Applying this method, miniaturized piezoelectric resonators and filters are developed for use in the medium frequency range below several megahertz.
A Miniaturized Face Shear Mode Quartz Crystal Resonator
Authors: Kawashima Hirofumi , Matsuyama Masaru
Published: March 2014

This paper describes a miniaturized face shear mode quartz crystal resonator of 4.2 to 6.0 MHz. An object of this paper is to clarify theoretically and experimentally frequency characteristics, frequency temperature behavior and electrical characteristics for the resonator. Another object is to provide a miniaturized resonator with high shock-resistance. The analysis results are then compared with the measured data. As a result, the frequency constant derived from the theoretical analysis agrees well with the measured values and the resonators with high shock-resistance are also found to have a sufficiently small series resistance R
1, a high quality factor and a zero temperature coefficient, even if it was extremely miniaturized.
Fundamental Equations of Electro-Acoustic Conversion for an Interdigital Surface-Acoustic-Wave Transducer by Using Force Factors
Authors: Kojima Toshihiro , Suzuki Tatsuo
Published: March 2014

This paper presents the new fundamental equations of electro-acoustic conversion for N-pair of IDT by using force factors. From these equations, the simplified three-port equivalent circuits have been derived. As an application, in the case that one of two acoustic ports is connected with the characteristic impedance, the two-port equivalent circuits for an IDT have also been derived in much simpler forms.
Magneto-Optic Devices using Interaction between Magnetostatic Surface Wave and Optical Guided Wave
Authors: Hasegawa Kazuo , Miyazaki Yasumitsu
Published: March 2014

An analysis of the optical TE-TM mode conversion by magnetooptic effect induced by magnetostatic surface wave (MSSW) is discussed. A typical MSSW waveguide has a thick layer for the convenient excitation of MSSW. However, the waveguide is not a single mode waveguide but multi-mode for the optical wavelength of 1.3 [µm]. We propose here the multi-layer waveguide consisting of the thin and thick magnetic layers that improves the characteristics of optical mode conversion. The efficiency of 100% is achieved over the interaction length of about 1.0 [cm] for the applied microwave power density of a few [mW/mm].
Note on Shimizu-Saito's Tracking Methods
Authors: Hayashi Shigeo , Sasaki Yukihiko
Published: March 2014

A flow-chart model is presented for Shimizu-Saito's resonance-tracking method which is based on rectification feedback. The model is solved numerically for a model resonator. The method is shown to be much faster than the phase-locked loop method if the values of the gain-admittance product are large, although too large values induce unstable oscillations into the system frequency.
An Encoder-Less Ultrasonic Stepping Motor Using Open-Loop Control System
Authors: Kusakabe Chiharu , Tomikawa Yoshiro , Takano Takehiro , Narita Kenetsu
Published: March 2014

The construction of a light-load ultrasonic stepping motor for a watch device, and its angular displacement control by the open-loop control are described. In this control system, a rotary encoder as an angular displacement sensor is not used.
A function of an angular displacement self-correction is added to an ultrasonic motor itself, applying a new type rotor and a new drive method. As a result, the correct setting of an angular displacement has been achieved with no use of the rotary encoder.
Inspection of Rotor and Stator Vibration of the Ultrasonic Motor Using Longitudinal and Torsional Vibrations
Authors: Aoyagi Manabu , Tomikawa Yoshiro
Published: March 2014

The present paper deals with some experimental inspections of vibration generated in a rotor and a stator of an ultrasonic motor using longitudinal and torsional vibrations. It is pointed out that the nonlinear phenomena of the vibration should be considered in the motor construction. The signal was picked up by adhered piezoelectric ceramics to inspect the vibration behaviors of the rotor and the stator. The signal contains some frequency components to distinguish nonlinear vibration unwanted for the motor generated in the rotor and the stator.
Ultrasonic Welding of Thin Metal Plates Using a Complex Vibration Welding Tip
Authors: Tsujino Jiromaru , Ueoka Tetsugi , Konda Hiroyuki , Kimura Yusuke
Published: March 2014

Ultrasonic welding of thin metal plates using a complex vibration welding tip is studied. The welding tip vibration locus shape is changed from linear, elliptical, to circular using a pair of the same frequency 27 kHz complex vibration systems. Aluminum and copper plate specimens of 0.5 to 1.0 mm thickness were welded successfully using this welding system. Required vibration amplitude is about half compare to a conventional system. Weld strength and weld area obtain by this system are larger, and welded area becomes more concentrated than these by a conventional system. The weld strength also was independent of specimen direction.
Measurements of Gel Rigidity Using Surface Waves
Authors: Choi Pak-Kon
Published: March 2014

Surface waves are used to measure gel rigidity on gelatin and agarose gels. The method employs the detection of a laser light deflected by surface waves excited with a PZT bimorph. Propagation time vs propagation distance gives surface wave velocity which provides the rigidity. The sol-gel transition, ageing effect and frequency dependence of the surface wave velocity are observed for gelatin. Frequency and temperature dependences of the surface wave velocity are observed for agarose. These results show the usefulness of the present system as a rigidity measuring method of soft materials.
Mechanical Properties of Chemical Gel In a Low Frequency Range
Authors: Miura Toshiaki , Tanaka Hajime
Published: March 2014

Chemical gelation kinetics and volume phase transition in poly-N-isopropyl acrylamide gel have been studied focusing on the low-frequency mechanical properties. The complex shear modulus of gel has been measured by a newly developed instrument. The method is turned out to be very powerful for characterizing the mechanical properties of soft condensed matters including the low-frequency relaxational behavior.