bluuebunny/crossref_metadata_2025 huggingface dataset:
An Interactive Tool for Outdoor Computer Controlled Cultivation of Microalgae in a Tubular Photobioreactor System
Authors: Dormido Raquel , Sánchez José , Duro Natividad , Dormido-Canto Sebastián , Guinaldo María , Dormido Sebastián
Published: March 2014

This paper describes an interactive virtual laboratory for experimenting with an outdoor tubular photobioreactor (henceforth PBR for short). This virtual laboratory it makes possible to: (a) accurately reproduce the structure of a real plant (the PBR designed and built by the Department of Chemical Engineering of the University of Almería, Spain); (b) simulate a generic tubular PBR by changing the PBR geometry; (c) simulate the effects of changing different operating parameters such as the conditions of the culture (pH, biomass concentration, dissolved O2, inyected CO2, etc.); (d) simulate the PBR in its environmental context; it is possible to change the geographic location of the system or the solar irradiation profile; (e) apply different control strategies to adjust different variables such as the CO2 injection, culture circulation rate or culture temperature in order to maximize the biomass production; (f) simulate the harvesting. In this way, users can learn in an intuitive way how productivity is affected by any change in the design. It facilitates the learning of how to manipulate essential variables for microalgae growth to design an optimal PBR. The simulator has been developed with Easy Java Simulations, a freeware open-source tool developed in Java, specifically designed for the creation of interactive dynamic simulations.
Visions of Sustainability in Bioeconomy Research
Authors: Pfau Swinda , Hagens Janneke , Dankbaar Ben , Smits Antoine
Published: March 2014

The rise of the bioeconomy is usually associated with increased sustainability. However, various controversies suggest doubts about this assumed relationship. The objective of this paper is to identify different visions and the current understanding of the relationship between the bioeconomy and sustainability in the scientific literature by means of a systematic review. After a search in several databases, 87 scientific journal articles were selected for review. Results show that visions about the relationship between bioeconomy and sustainability differ substantially. Four different visions were identified, including: (1) the assumption that sustainability is an inherent characteristic of the bioeconomy; (2) the expectation of benefits under certain conditions; (3) tentative criticism under consideration of potential pitfalls; and (4) the assumption of a negative impact of the bioeconomy on sustainability. There is considerable attention for sustainability in the scientific bioeconomy debate, and the results show that the bioeconomy cannot be considered as self-evidently sustainable. In further research and policy development, good consideration should therefore be given to the question of how the bioeconomy could contribute to a more sustainable future. Furthermore, it is stressed that the bioeconomy should be approached in a more interdisciplinary or trans-disciplinary way. The consideration of sustainability may serve as a basis for such an approach.
Multiple Toxin-Antitoxin Systems in Mycobacterium tuberculosis
Authors: Sala Ambre , Bordes Patricia , Genevaux Pierre
Published: March 2014

The hallmark of Mycobacterium tuberculosis is its ability to persist for a long-term in host granulomas, in a non-replicating and drug-tolerant state, and later awaken to cause disease. To date, the cellular factors and the molecular mechanisms that mediate entry into the persistence phase are poorly understood. Remarkably, M. tuberculosis possesses a very high number of toxin-antitoxin (TA) systems in its chromosome, 79 in total, regrouping both well-known (68) and novel (11) families, with some of them being strongly induced in drug-tolerant persisters. In agreement with the capacity of stress-responsive TA systems to generate persisters in other bacteria, it has been proposed that activation of TA systems in M. tuberculosis could contribute to its pathogenesis. Herein, we review the current knowledge on the multiple TA families present in this bacterium, their mechanism, and their potential role in physiology and virulence.
TRAPPING ELECTROMAGNETIC SOLITONS IN CYLINDERS
Authors: Funaro Daniele
Published: March 2014

Electromagnetic waves in vacuum or dielectrics can be confined in unbounded cylinders in such a way that they turn around the main axis. For particular choices of the cylinder's section, interesting stationary configurations may be assumed. By refining some results obtained in previous papers, additional more complex situations are examined here. For such peculiar guided waves an explicit expression is given in terms of Bessel's functions. Possible applications are in the development of whispering gallery resonators.
PIKfyve, a Class III Lipid Kinase, Is Required for TLR-Induced Type I IFN Production via Modulation of ATF3
Authors: Cai Xinming , Xu Yongyao , Kim You-Me , Loureiro Joseph , Huang Qian
Published: March 2014

Type I IFN plays a key role in antiviral responses. It also has been shown that deregulation of type I IFN expression following abnormal activation of TLRs contributes to the pathogenesis of systemic lupus erythematosus. In this study, we find that PIKfyve, a class III lipid kinase, is required for endolysosomal TLR-induced expression of type I IFN in mouse and human cells. PIKfyve binds to phosphatidylinositol 3-phosphate and synthesizes phosphatidylinositol 3,5-bisphosphate, and plays a critical role in endolysosomal trafficking. However, PIKfyve modulates type I IFN production via mechanisms independent of receptor and ligand trafficking in endolysosomes. Instead, pharmacological or genetic inactivation of PIKfyve rapidly induces expression of the transcription repressor ATF3, which is necessary and sufficient for suppression of type I IFN expression by binding to its promoter and blocking its transcription. Thus, we have uncovered a novel phosphoinositide-mediated regulatory mechanism that controls TLR-mediated induction of type I IFN, which may provide a new therapeutic indication for the PIKfyve inhibitor.
Finiteness of 3-manifolds associated with non-zero degree mappings
Authors: Boileau Michel , Rubinstein J. Hyam , Wang Shicheng
Published: March 2014

We prove a finiteness result for the

\partial

-patterned guts decomposition of all

3

-manifolds obtained by splitting a given orientable, irreducible and

\partial

-irreducible 3-manifold along a closed incompressible surface. Then using the Thurston norm, we deduce that the JSJ-pieces of all 3-manifolds dominated by a given compact 3-manifold belong, up to homeomorphism, to a finite collection of compact 3-manifolds. We show also that any closed orientable 3-manifold dominates only finitely many integral homology spheres and any compact orientable 3-manifold dominates only finitely many exteriors of knots in

S^3

.
Moments on Riemann surfaces and hyperelliptic Abelian integrals
Authors: Gavrilov Lubomir , Pakovich Fedor
Published: March 2014

In the present paper we solve the following different but interrelated problems: (a) the moment problem on Riemann surfaces, (b) the vanishing problem for polynomial Abelian integrals of dimension zero on the projective plane, (c) the vanishing problem for polynomial hyperelliptic Abelian integrals.
Denitrification by large NAT particles: the impact of reduced settling velocities and hints on particle characteristics
Authors: Woiwode W. , Grooß J.-U. , Oelhaf H. , Molleker S. , Borrmann S. , Ebersoldt A. , Frey W. , Gulde T. , Khaykin S. , Maucher G. , Piesch C. , Orphal J.
Published: March 2014

Abstract. Vertical redistribution of HNO3 through condensation, sedimentation and evaporation of large HNO3-containing particles inside polar stratospheric clouds (PSCs) plays an important role in the chemistry of the Arctic winter stratosphere. In situ observations by the particle probe FSSP-100 during the RECONCILE campaign indicate unexpected large potential NAT (nitric acid trihydrate) particles inside PSCs. The observations can hardly be explained assuming particles with compact morphology and spherical shape due to limited growing time at temperatures below the existence temperature of NAT (TNAT). Utilizing simulations by the CLaMS and measurements by the airborne Fourier transform infrared spectrometer MIPAS-STR we study the impact of reduced settling velocities of NAT particles on vertical HNO3 redistribution. Reduced settling velocities are expected for spherical NAT particles with low mass density or aspheric NAT particles that might explain the maximum sizes of the particles observed in situ. The results of our study support the hypothesis that denitrification is produced by significantly aspheric (i.e. columnar) compact NAT particles which are characterised by reduced settling velocities.
Polycyclic aromatic hydrocarbons in atmospheric aerosols and air–sea exchange in the Mediterranean
Authors: Mulder M. D. , Heil A. , Kukučka P. , Klánová J. , Kuta J. , Prokeš R. , Sprovieri F. , Lammel G.
Published: March 2014

Abstract. Polycyclic aromatic hydrocarbons (PAH) concentration in air of the central and eastern Mediterranean in summer 2010 was 1.45 (0.30–3.25) ng m−3, with ≈8% in the particulate phase, associated with particles < 0.25 μm. The diffusive air–sea exchange fluxes of fluoranthene and pyrene were mostly found net-depositional or close to phase equilibrium, while retene was net-volatilisational in a large sea region. Regional fire activity records in combination with box model simulations suggest that seasonal depositional input of retene from biomass burning into the surface waters during summer is followed by an annual reversal of air–sea exchange, while inter-annual variability is dominated by the variability of the fire season. It is concluded that future negative emission trends or interannual variability of regional sources may trigger the sea to become a secondary PAH source through reversal of diffusive air–sea exchange.
Development of a semi-parametric PAR partitioning model for the contiguous US
Authors: Kathilankal J. C. , O'Halloran T. L. , Schmidt A. , Hanson C. V. , Law B. E.
Published: March 2014

Abstract. A semi-parametric PAR diffuse radiation model was developed using commonly measured climatic variables from 44 site-years of data from 9 AmeriFlux sites. The model has a logistic form and improves upon previous efforts, using a larger data set and physically viable climate variables as predictors, including relative humidity, clearness index, surface albedo, and solar elevation angle. Model performance was evaluated by comparison with a simple cubic polynomial model developed for the PAR spectral range. The logistic model outperformed the polynomial model with an improved coefficient of determination and slope relative to measured data (logistic: R2 = 0.85; slope = 0.86; cubic: R2 = 0.82; slope = 0.83), making this the most robust PAR-partitioning model for the US subcontinent currently available.
Identification and simulation of space-time variability of past hydrological drought events in the Limpopo river basin, Southern Africa
Authors: Trambauer P. , Maskey S. , Werner M. , Pappenberger F. , van Beek L. P. H. , Uhlenbrook S.
Published: March 2014

Abstract. Droughts are widespread natural hazards and in many regions their frequency seems to be increasing. A finer resolution version (0.05° x 0.05°) of the continental scale hydrological model PCR-GLOBWB was set up for the Limpopo river basin, one of the most water stressed basins on the African continent. An irrigation module was included to account for large irrigated areas of the basin. The finer resolution model was used to analyse droughts in the Limpopo river basin in the period 1979–2010 with a view to identifying severe droughts that have occurred in the basin. Evaporation, soil moisture, groundwater storage and runoff estimates from the model were derived at a spatial resolution of 0.05° (approximately 5 km) on a daily time scale for the entire basin. PCR-GLOBWB was forced with daily precipitation, temperature and other meteorological variables obtained from the ERA-Interim global atmospheric reanalysis product from the European Centre for Medium-Range Weather Forecasts. Two agricultural drought indicators were computed: the Evapotranspiration Deficit Index (ETDI) and the Root Stress Anomaly Index (RSAI). Hydrological drought was characterised using the Standardized Runoff Index (SRI) and the Groundwater Resource Index (GRI), which make use of the streamflow and groundwater storage resulting from the model. Other more widely used drought indicators, such as the Standardized Precipitation Index (SPI) and the Standardized Precipitation Evaporation Index (SPEI) were also computed for different aggregation periods. Results show that a carefully set up process-based model that makes use of the best available input data can successfully identify hydrological droughts even if the model is largely uncalibrated. The indicators considered are able to represent the most severe droughts in the basin and to some extent identify the spatial variability of droughts. Moreover, results show the importance of computing indicators that can be related to hydrological droughts, and how these add value to the identification of droughts/floods and the temporal evolution of events that would otherwise not have been apparent when considering only meteorological indicators. In some cases, meteorological indicators alone fail to capture the severity of the drought. Therefore, a combination of some of these indicators (e.g. SPEI-3, SRI-6, SPI-12) is found to be a useful measure for identifying hydrological droughts in the Limpopo river basin. Additionally, it is possible to make a characterisation of the drought severity, indicated by its duration and intensity.
A review of droughts in the African continent: a geospatial and long-term perspective
Authors: Masih I. , Maskey S. , Mussá F. E. F. , Trambauer P.
Published: March 2014

Abstract. This paper presents a comprehensive review and analysis of the available literature and information on droughts to build a continental, regional and country level perspective on geospatial and temporal variation of droughts in Africa. The study is based on the review and analysis of droughts occurred during 1900–2013 as well as evidence available from past centuries based on studies on the lake sediment analysis, tree-ring chronologies and written and oral histories and future predictions from the global climate change models. Most of the studies based on instrumental records indicate that droughts have become more frequent, intense and widespread during the last 50 yr. The extreme droughts of 1972–1973, 1983–1984 and 1991–1992 were continental in nature and stand unique in the available records. Additionally, many severe and prolonged droughts were recorded in the recent past such as the 1999–2002 drought in Northwest Africa, 1970s and 1980s droughts in West Africa (Sahel), 2010–2011 drought in East Africa (Horn of Africa) and 2001–2003 drought in Southern and Southeast Africa, to name a few. The available (though limited) evidence before the 20th century confirms the occurrence of several extreme and multi-year droughts during each century, with the most prolonged and intense droughts that occurred in Sahel and Equatorial East Africa regions. Complex and highly variant nature of many physical mechanisms such as El Niño-Southern Oscillation (ENSO), Sea Surface Temperature (SST) and land–atmosphere feedback adds to the daunting challenge of drought monitoring and forecasting. The future predictions of droughts based on global climate models indicate increased droughts and aridity at the continental scale but large differences exist due to model limitations and complexity of the processes especially for Sahel and North Africa regions. However, the available evidence from the past clearly shows that the African continent is likely to face extreme and widespread droughts in future. This evident challenge is likely to aggravate due to slow progress in drought risk management, increased population and demand for water and degradation of land and environment. Thus, there is a clear need for increased and integrated efforts in drought mitigation to reduce the negative impacts of droughts anticipated in future.
Groundwater as an emergency source for drought mitigation in the Crocodile River catchment, South Africa
Authors: Mussá F. E. F. , Zhou Y. , Maskey S. , Masih I. , Uhlenbrook S.
Published: March 2014

Abstract. Global climate change has received much attention worldwide in the scientific as well as in the political community, indicating that changes in precipitation, extreme droughts and floods may threaten increasingly many regions. Drought is a natural phenomenon that may cause social, economical and environmental damages to the society. In this study, we assess the drought intensity and severity and the groundwater potential to be used as a supplement source of water to mitigate drought impacts in the Crocodile River catchment, a water-stressed sub-catchment of the Incomati River catchment in South Africa. The research methodology consists mainly of three parts. First, the spatial and temporal variation of the meteorological and hydrological drought severity and intensity over the catchment were evaluated. The Standardized Precipitation Index (SPI) was used to analyse the meteorological drought and the Standardized Runoff Index (SRI) was used for the hydrological drought. Second, the water deficit in the catchment during the drought period was computed using a simple water balance method. Finally, a groundwater model was constructed in order to assess the feasibility of using groundwater as an emergency source for drought impact mitigation. Results show that the meteorological drought severity varies accordingly with the precipitation; the low rainfall areas are more vulnerable to severe meteorological droughts (lower and upper crocodile). Moreover, the most water stressed sub-catchments with high level of water uses but limited storage, such as the Kaap located in the middle catchment and the Lower Crocodile sub-catchments are those which are more vulnerable to severe hydrological droughts. The analysis of the potential groundwater use during droughts showed that a deficit of 97 Mm3 yr−1 could be supplied from groundwater without considerable adverse impacts on the river base flow and groundwater storage. Abstraction simulations for different scenarios of extremely severe droughts reveal that it is possible to use groundwater to cope with the droughts in the catchment. However, local groundwater exploitation in Nelspruit and White River sub-catchment will cause large drawdowns (> 10 m) and high base flow reduction (> 20%). This case study shows that conjunctive water management of groundwater and surface water resources is the necessary to mitigate the impacts of droughts.
Education/obrazovanie as an experience of an encounter
Authors: Lobok Alexander
Published: March 2014

Experience is something which cannot be received like knowledge from someone else. Experience is what you live through yourself. Therefore experience is something that belongs only to the person him/herself. It is his/her absolutely individual and irreplaceable testament to reality. Every person without exception has HIS/HER absolutely unique experience of the encounter with culture (= experience of education/obrazovanie). The multiple trajectories of this inner experience are the most profound and significant result of the educational process. And the increase in the diversity of such trajectories of inner experience can be seen as a key indicator of what we call the quality of education/obrazovanie.Video 1 https://vimeo.com/88029209 Video 2 https://vimeo.com/88032506
Multiple Visions, Multiple Viewpoints: Apparitions in a Polish-German Borderland, 1877-1880
Authors: Dabrowski Patrice M.
Published: March 2014

The article views the little-known apparitions of the Blessed Virgin Mary in the village of Dittrichswalde (Gietrzwałd) in 1877-80 through the prism of the varied religious imagery they evoked and promoted. After considering pre-1877 fixed images of and attitudes toward the Virgin Mary in their historical and cultural context in the Polish-German borderland of Ermland (Warmia), the initial images of the apparitions as well as the three primary dramatis personae, two young female visionaries and the parish priest, are introduced. Further visionaries, the pilgrims, the official ecclesiastic investigation (including the doctors’ examination of the visionaries), and a number of disquieting revelations complicate the picture more, as did the identification of Poles from across the German-Polish border as well as the local Warmians. Ultimately, a multiplicity of religious images, fluid as well as static, became available to the faithful during this challenging period for the Roman Catholic Church that was the Kulturkampf in the German Empire.
Preservation of Kidneys by Machine Perfusion Influences Gene Expression and May Limit Ischemia/Reperfusion Injury
Authors: Wszola Michal , Kwiatkowski Artur , Domagala Piotr , Wirkowska Agnieszka , Bieniasz Monika , Diuwe Piotr , Kieszek Rafał , Durlik Magdalena , Chmura Andrzej
Published: March 2014

Context

Machine perfusion improves graft survival. Histopathologic analysis reveals a lower incidence of chronic rejection and interstitial fibrosis in kidneys preserved with machine perfusion. Ischemic/reperfusion injury may help to explain these findings.

Objective

To assess the activation of genes correlated with ischemic/reperfusion injury in kidneys preserved under different conditions before transplant.

Design/Patients

Between 2005 and 2006, 69 kidney biopsy specimens were collected and patients were followed up for 5 years after that.

Intervention

Before transplant, kidneys were preserved with machine perfusion or cold storage. Donors from the machine perfusion and cold storage groups did not differ with regard to age, sex, or hemodynamic status. Recipients were divided into 5 groups: expanded criteria donor–machine perfusion (n = 16), standard criteria donor–machine perfusion (n = 10), expanded criteria donor–cold storage (n = 9), and standard criteria donor–cold storage (n = 27); 7 kidneys were retrieved from living related donors.

Main Outcome Measures

Biopsies were done 30 minutes after reperfusion. Interleukin-1β, vascular endothelial growth factor, heme oxygenase-1, and hypoxia-inducible factor–1 gene expression levels were analyzed.

Results

Mean expression levels of hypoxia-inducible factor–1α were significantly higher in the cold storage groups, and lower in the machine perfusion and living-related donor groups. Five-year graft survival was significantly ( P < .05) lower in the expanded criteria donor–cold storage group (66%) than in the standard criteria donor–machine perfusion group (90%). Machine perfusion influences gene expression related to hypoxia during reperfusion and may improve the long-term results of kidney transplant.
Evaluation of the junction interface of the crystalline germanium heterojunction solar cells
Authors: Nakano Shinya , Takeuchi Yoshiaki , Kaneko Tetsuya , Kondo Michio
Published: March 2014

A junction interface of hydrogenated amorphous silicon/crystalline germanium heterojunction solar cells that employ substrates of different crystalline orientations and PH3 exposure interface treatment was evaluated. We confirmed that the degree of heteroepitaxial growth depends on the crystalline orientation and is suppressed by PH3 exposure treatment. In addition, the PH3 exposure treatment forms a depletion layer near the interface in the crystalline germanium substrate. The heteroepitaxial growth and depletion layers have a great effect on the solar cell performance. Accordingly, a conversion efficiency of 6.54% was obtained by optimizing the interface properties.
SAW Resonator and Resonator Filter on Li2B4O7 Substrate
Authors: Ebata Yasuo , Koshino Masayoshi
Published: March 2014

Lithium tetraborate (Li2B4O7) single crystal has attracted attention as a piezoelectric substrate for SAW devices. This paper focuses on its application to a SAW resonator. Reflection characteristics for aluminum strips and configuration suppressing surface-to-bulk-wave conversion are discussed. Results prove that the strips on Li2B4O7 substrate reflect efficiently, compared with those on the other substrates, and that a newly developed configuration improves the resonator Q at least twice. Further, a low insertion loss of 2.5 dB is achieved for a paging receiver filter.
A New Unidirectional SAW Transducer with a Simplified External Network
Authors: Fujita Yuji , Shiba Takashi , Takahashi Toshimitsu , Yamada Jun
Published: March 2014

A group-type unidirectional SAW transducer with new electrode constitution and new phase shifter has been developed. It is designed to have non-quadratic geometrical phase difference between sending and reflecting electrodes and the electrodes have different finger pairs. In addition, the phase shifter is constituted by only one capacitor and is fabricated on the same piezoelectric substrate. Consequently, inductors of the external network can be reduced. Furthermore, as suppression of backward response is more optimal, the transducer eliminates any adjustment with low loss and low
ripple.
Role of Whispering Gallery Mode and Ray in Concave Boundary
Authors: Ishihara Toyohiko , Nakata Atsushi , Toda Kohji
Published: March 2014

Acoustical fields excited on a concave rigid wall by a source located on the wall are represented by a combination of either a whispering gallery (WG) mode and continuous spectrum or geometric acoustical ray and lowest order WG mode. The role of the WG mode and acoustical ray is clarified and the relation between the WG modes in the normal mode theory and the acoustical rays in the ray theory is investigated based on numerical calculations from an analytically derived formula. The pressure fields appreciably far from the source in the azimuthal direction can be obtained by super-posing specific WG modes only in the high frequency limit.
Evaluation of Semiconductor Wafers Utilizing Superconducting Photorelaxation Spectroscopy
Authors: Kasai Yuji , Sugishita Akimitsu , Mochiku Takashi , Iguchi Ienari
Published: March 2014

We report a new technique which utilizes a superconducting tunnel junction as a phonon detector to detect none-quilibrium phonons through a nonradiative process in optically illuminated semiconductors. The observed phonon
signal as a function of wavelength of the light exhibits a clear bandgap structure for semiconductor crystals such as Si or GaAs wafers. This result indicates that the method is very promising for studying the energy structure of semiconductors.
Interference Fringes in Reflection Acoustic Microscopy
Authors: Kojima Seiji
Published: March 2014

Two types of interference fringes have been studied in reflection acoustic microscopy. Firstly, the asymmetric fringe patterns around an inclined domain wall have been investigated and it has been proved that the inclination caused the asymmetry due to the difference of the reflectivities of the leaky Rayleigh waves on both sides of the wall. Next, the elongated interference rings around a very small hole have been investigated and it has been found that the elongation is due to the anisotropy of acoustic phase velocities.
Measurement of Ultrasonic Shear Wave Amplitude Using Raman-Nath Parameter
Authors: Kojoh Hiroki , Arakawa Kazuo , Takahashi Kiyoshi , Nagai Satoshi
Published: March 2014

The acousto-optic-diffraction method was employed to measure the amplitude of ultrasonic shear waves in a glassy polymer, poly(methyl methacrylate). The frequency was near 400 kHz, which is typically used in ultrasonic fractography studies of this material. The waves measured have an amplitude of 104-105 Pa and the amplitude attenuates almost exponentially. The attenuation coefficient obtained is about 0.21 Np/cm.
Multi-Channel External Modulation Using Acousto-Optic Diffraction
Authors: Urabe Heijiro , Toda Kohji
Published: March 2014

Acousto-optic diffraction with multiple acoustic waves in water is examined to realize multi-channel modulation of an optical beam. Ultrasound, operating as a diffraction grating, is generated via a mode conversion from a surface acoustic wave (SAW) on the free surface of a piezoelectric plate. The operation principle and practical result are described for two independent signals in the Bragg regime. This is supported by experimental measurement.
Use of Acoustic Emission and Seismic Tomography Techniques to Study Sinkhole Development
Authors: Jr. H. Reginald Hardy, , Belesky Robert M.
Published: March 2014

The uncontrolled development of cavities near the earth's surface, due to natural or man-made causes, pose a major engineering hazard. Regardless of the cause, these cavities can result in localized instabilities such as the collapse of highway or airport runway pavements, foundation subsidence or collapse, and dam leakage. The purpose of the study outlined in this paper was to investigate the feasibility of using acoustic emission and seismic tomography techniques to study the development of one type of near-surface cavity known as a “sinkhole.” In recent years, sinkholes have developed under large sections of the airport runway and taxiway complex at the Capital City Airport, near Harrisburg, Pennsylvania, U.S.A.. During the study, instrumentation for carrying out low-frequency acoustic emission and near-surface S-wave seismic tomography studies were installed at selected areas. This paper will present preliminary results of this ongoing study.
Ultrasonic Generation by Laser-induced Grating and its Application to Chemical Measurements
Authors: Harata Akira , Sawada Tsuguo , Gohshi Yohichi
Published: March 2014

Thermal grating and tunable ultrasonic waves are generated by the intersection of two laser beams of the same frequency, and are detected by Bragg diffraction technique. Using this technique, trace analysis and ultrasonic velocity and attenuation measurements were carried out for liquid samples. This method has been proved to be a useful tool for the nondestructive and noncontact evaluation of condensed matter such as liquids.
High Temperature Cell Using Polyimide Buffer for Ultrasonic Spectroscopy
Authors: Hiramatsu Nobuyasu , Taki Seiji , Matsushige Kazumi
Published: March 2014

A high temperature cell for ultrasonic spectroscopy is made by utilizing a polyimide buffer rod with good acoustic impedance matching and high thermal stability and by cooling a wide band PVDF transducer with running water. The temperature limit of the polyimide as a buffer is above 220°C in the frequency range from 2 to 6 MHz, while it is 300°C for the low frequency (2–3 MHz) region. To prove its performance, temperature dependence of the acoustic properties of nylon 6 are measured using this cell. Its dispersion and melting behavior are clearly observed.
Experimental Study of Ultrasonic Velocity Measurement Using the Pulse Superposition Method
Authors: Kameyama Hiroshi
Published: March 2014

Details of the pulse superposition method have been studied using an automatic control equipment. With this equipment, a state in phase is easily determined by three justifying conditions so that the absolute value of velocity can be precisely decided. By controlling the number (n) of the driving pulse, it is found that the number of sub-peaks between the larger peaks of the summed wave is n-2 and that, in proportion to n, the ratio of the peak value decreases and the ratio of half width increases. Sensitivity of the absolute value of velocity reached 1.4×10-4.
Real-Time Two-Dimensional Blood Flow Imaging Using Ultrasound Doppler
Authors: Kasai C. , Namekawa K.
Published: March 2014

A newly developed two-dimensional blood flow imaging system which uses ultrasound is described, in which blood flow in a given cross section of a live organ is displayed in real time. To perform this, an autocorrelation technique is used. Obtained blood flow data are displayed in color on a TV screen superimposed on black/white tissue images. The flow direction, speed and variance are expressed by differences in color and brightness. Experiments were conducted with a mechanical and an electrical scanner and good agreement with the theory was obtained. Studies on clinical significance have also been carried out for normal and diseased hearts with successful results.
Quasi-Ideal Beam Pattern Transducer
Authors: Sasakura Toyoki , Endo Yasuhiko
Published: March 2014

Recent advancements in electronics technology have led to the development of a new generation of underwater acoustic equipment. However, the development of the transducer, the sensor used in this equipment, has not advanced to the same degree as other components.
For that reason, we have developed a transducer with a quasi-ideal beam pattern to perform highly accurate underwater acoustic measurements. In this paper, the basic principles for beam forming and the directivity pattern obtained in some of the experiments are introduced.
Electrical and Optical Properties of Fluorinated Ferroelectric Liquid Crystal
Authors: Taniguchi Hiroki , Ozaki Masanori , Yoshino Katsumi
Published: March 2014

Ferroelectric liquid crystals with spontaneous polarization exceeding 10-7 C/cm2 have been prepared introducing a fluorinated carbon, which also indicate anomalous dielectric behaviour due to the wall and field effect. Their electro-optic effects have been studied and it is clarified that these materials demonstrate high response speed electro-optic effects corresponding to their large spontaneous polarization.
Reversal of Spontaneous Polarization Direction in Ferroelectric Liquid Crystal with Temperature
Authors: Nakao Kenji , Ozaki Masanori , Yoshino Katsumi
Published: March 2014

Anomalous dielectric behavior in biphenyl ester series of ferroelectric liquid crystals are reported. Even in the chiral smectic-C phase, the spontaneous polarization becomes zero at a certain temperature-T
m and increases again below T
m with decreasing temperature. Moreover, At T
m the reversal of the sign of tilt angle is observed, indicating the reversal of the sign of the spontaneous polarization. However, this anomaly is not observed in the measurement of the helicoidal pitch and is not influenced by the application of pressure below several kbar. The origin of this anomaly is also discussed in terms of molecular interactions and conformation.
Sintering of Submicron Powders Prepared by Ball Milling
Authors: Tashiro Shinjiro , Sasaki Norio , Tsuji Yuuji , Igarashi Hideji , Okazaki Kiyoshi
Published: March 2014

The calcined powders of PLZT 2/50/50 and low temperature sinterable dielectric ceramics were ball milled for a maximum of 240 h using small zirconia balls of 1 mm and 3 mm in diameter. The powders were ground down to 0.2 µm in average particle size. The sintering temperature could be lowered 100∼200°C by making the particle size of powders very fine. Furthermore, the combination of the fine powder and the liquidus sintering aid was able to make the sintering temperature low additionally. Dielectric and piezoelectric properties of the ceramics fabricated at relatively low temperature from the fine powders are compared with those of the ceramics fabricated from the usual powders.
Pulse Mode Operation for Piezoelectric Ceramic Actuator
Authors: Takahashi Sadayuki , Yano Takeshi , Hori Shinichi , Sato Eiichi
Published: March 2014

Multilayer piezoelectric ceramic actuators were driven in large amplitude pulse modes by a new charge-discharge circuit with a series inductor. About 56% of the supplied electrical energy was recovered for the mechanically unloaded actuator. About 21% was lost as heat at the actuator. The maximum electro-mechanical energy conversion efficiency for the mechanically loaded actuator was 36%.
Measurments of Equivalent Circuit Parameters of Piezoelectric Ceramic Resonators
Authors: Kato Terumasa , Imai Atsuo
Published: March 2014

Evaluation method of piezoelectric ceramics has been investigated. The center of admittance circle was determined by the least square method, and the parallel complex capacitance C
0(=C
0'-j
C
0'') were deduced. From C
0 and the measured data, motional capacitance C
1, motional inductance L
1 and motional resistance R
1 were calculated by using the least square method. The equivalent circuit parameters were determined on PZT ceramics Pb(Zr1-x
Ti
x
)O3. At x=0.47, the real parts of the parallel capacitance C
0' and motional capacitance C
1 showed maximum value, 2.685 nF and 454 pF, respectively and at x=0.44, electromechanical coupling factor k

p
showed the maximum value 51%.
Dielectric-Properties of Ceramics in the System Pb(Mg1/2W1/2)O3–Pb(Ti1-xZrx)O3–ZnO
Authors: Sakabe Yukio , Nishioka Goro , Fujino Masaru
Published: March 2014

Dielectric properties of the relaxor ferroelectric ceramics in the system Pb(Mg1/2W1/2)O3–PbTiO3–PbZrO3–ZnO were investigated. The dielectric constant vs temperature curve for these dielectrics exhibited dual peaks with increasing zinc oxide up to 8 mol%. This resulted in a small capacitance change over widely extended temperature ranges. A double hysteresis loop and the dual peaks of dielectric constant curve were explained as a result of dielectric aging phenomenon associated with nonstoichiometry of the compositions caused by the addition of zinc oxide.
Piezoelectric Anisotropy in Lead Titanate System Ceramics
Authors: Tashiro Shinjiro , Oikawa Yukio , Igarashi Hideji , Okazaki Kiyoshi
Published: March 2014

Pizoelectric anisotropy of PbTiO3 ceramics were experimentally investigated and discussed. The correlation between piezoelectric anisotropy and elastic constants were obtained in (Pb, (Bi, Na))((Fe, Nb)Ti)O3 ceramics. (Pb, Ca)((Co, W)Ti)O3 ceramics with k

t
=0.54 and k

p
∼0 was expanded and contracted in a transverse direction by application of a dc electric field in spite of the disappearance of the resonance of radial mode vibration, and the magnitude of displacement was equivalent to that of other modified PbTiO3 ceramics. It was estimated that the disappearance of radial mode vibration for (Pb, Ca)((Co, W)Ti)O3 ceramics was caused by a frequency dependence of transverse displacement.
PbTiO3 Based Pyroelectric Ceramics Modified with Stannate Compounds
Authors: Sasazawa Kazuo , Oshima Kazuyuki , Yamaoka Nobutatsu
Published: March 2014

The properties of PbCa(Cu, Nb)TiO3–NiSnO3 based pyroelectric ceramics were investigated.
Microstructures were examined by a X-ray microanalysis. The pyroelectric ceramics were consisted of three individual of PbCa(Cu, Nb)TiO3 phase NiSnO3–NiTiO3 compound phase and SnO2 rich phase in a ceramic composition. Pyroelectric properties of the ceramics were F
v of 8.5×10-11 C cm/J and Curie point of 272°. By an addition of NiSnO3 to Pb0.7Ca0.3(Cu1/3Nb2/3)0.05Ti0.95O3, F
v were up to the high value with an increase of P(P=5.8×10-8 C/cm2°C) and a decrease of ε

s
(ε

s
=220).
Medium Voltage Large Capacitance Multilayer Ceramic Capacitors Employing Lead Perovskite Ferroelectric Material
Authors: Yamashita Yohachi , Mukaeda Satoshi , Inagaki Katsumi , Ohba Norikazu , Handa Kiyoji
Published: March 2014

Multilayer ceramic capacitors (MLCs), having 1 µF actual capacitance value at 200 V, have been fabricated using modified lead zinc niobate-lead magnesium niobate-lead titanate relaxor dielectric material. The MLCs can meet each of Y5U and Y5S specifications in Electronic Industries Association (EIA) standard. These MLCs are promising candidates replacing conventional film capacitor or aluminum electrolytic capacitor,especially for the medium voltage application such as a input filter of switching power supply in a high frequency region.
Piezoelectric Anisotropy of (Pb, Ca)(Ti, (Co, W))O3 Ceramics
Authors: Tashiro Shinjiro , Gotoh Kenichi , Igarashi Hideji
Published: March 2014

In order to make clear the origin of zero value of k31 in calcium-modified PbTiO3 ceramics, the transverse displacements induced by application of high dc and ac electric fields were experimentally investigated, and were compared with those of PZT ceramics with the composition of a morphotropic phase boundary. The d31 coefficient of Ca-modified PbTiO3 ceramics changed with the amplitude of the applied ac field, and it was not zero under high electric field, although k31 was zero under small signal field. The mechanism of the zero value of transverse coupling factor k31 was discussed on the basis of the experimental results.
Fabrication of Li2B4O7 Piezoelectric Thin Films
Authors: Uno Takehiko
Published: March 2014

Piezoelectric thin films of Li2B4O7 are fabricated by two methods, RF sputter deposition and vapor deposition under a low gas pressure. RF sputter deposition is found unsuitable because the sputtered Li2B4O7 tends to decompose during the process, c-axis oriented Li2B4O7 films with good piezoelectric characteristics, on the other hand, are prepared by vapor deposition under a low gas pressure.
Design of SAW Sensor in Liquid
Authors: Shiokawa Showko , Moriizumi Toyosaka
Published: March 2014

A SAW sensor in a liquid medium utilizing a leaky SAW mode having a shear horizontal displacement has been studied, and the device sensitivities have been investigated both theoretically and experimentally. Sensors of liquid viscosity and mass loading have been demonstrated utilizing the present mode on 36° rotated Y-cut X-propagation LiTaO3.
Zero Slope Temperature SiC/SiO2/LiTaO3 Substrate for Boundary Acoustic Waves
Authors: Irino Toshio , Watanabe Takaya , Shimizu Yasutaka
Published: March 2014

Zero slope temperature SiO2/X-148°Y LiTaO3 substrate has been proposed for use in packageless SAW devices. However, the SiO2 film is required to be about three times the wavelength and, therefore, is easily removed by temperature variation. In this paper, SiC overcoat on SiO2 to reduce the film thickness is proposed. The calculated energy concentration to the middle layer is better than the two media structure. The experimental result agreed with the theory and zero slope temperature was obtained when the total thickness of SiC and SiO2 was about 2.5 times the wavelength.
BGS-type Magneto-Surface-Acoustic-Wave Devices Utilizing Horizontally Polarized PZT-Substrates
Authors: Fujita Naoyuki , Inoue Mitsuteru , Tsuboi Yoshihiro , Fujii Toshitaka
Published: March 2014

BGS-type magneto-surface-acoustic-wave(MSAW) devices were constructed by depositing highly magnetostrictive amorphous Fe-Co-B ternary alloy films by RF-sputtering on horizontally polarized PZT-substrates, since this type of MSAW is expected from our theory to have wide controllability of the propagation properties with externally applied magnetic field in comparison with those of the Rayleigh-type MSAW. We measured changes of attenuation and phase velocity as a function of magnetic field, and the results agree qualitatively with those obtained by the theoretical analysis.
Diminution of Micro-Eddy-Current Losses in Magneto-Surface-Acoustic-Wave Propagation Utilizing Multilayered Magnetostrictive Film Separated by Insulating Layers
Authors: Inoue Mitsuteru , Fujita Naoyuki , Tsueoi Yoshihiro , Fujii Toshitaka
Published: March 2014

Propagation properties of the Rayleigh-type magneto-surface-acoustic-wave in multilayered magnetic alloy films were studied theoretically, where the films consisted of highly magnetostrictive layers separated by insulating layers. The analysis revealed that multilayer structure is very effective for improvement of magneto-acoustic quantities by reducing micro-eddy-current losses. We further found that the key factor in obtaining optimal conditions in the layered structure is total thickness of the insulating layers (=number of the layers × thickness of the individual layer).
Modal Vibration Control of Elastic Systems Using Wave-Trapped Horns
Authors: Adachi Kazunari , Ueha Sadayuki
Published: March 2014

A method for modal vibration control of elastic systems using additional vibrators called `wave-trapped horns' is proposed. Experimental verification of the method has been done for several vibrating tools whose shapes are often adopted in ultrasonic plastic welding. The validity of the method is confirmed.
Quantitative Measurement of Ultrasonic Wave Stress in a Solid by Stroboscopic Photoelasticity
Authors: Date Kazuhiro , Shimada Heihachi
Published: March 2014

We have developed a method of visually measuring and evaluating an ultrasonic wave stress emitted from a probe into a model similar to the actual material to be used, by using Stroboscopic photoelasticity. The visualization of sound pressure distribution can be achieved by synthesizing two photoelastic pictures, in which the direction of the principal axis of linear polariscopes are different by 45 degrees. The measurement of sound pressure field generated by commercial ultrasonic probes was done using this method.
Nondestructive Evaluation for Distribution of Stress Using Photoacoustic Microscope
Authors: Kasai Masanobu , Matsui Yuji , Miyauchi Kouji , Sawada Tsuguo
Published: March 2014

The distribution of stress in a model sample of metal was measured by photoacoustic microscope (PAM) nondestructively. Experimental results were compared with calculated results using finite elements method. PAM imaging of the area of ion implantation in metal was demonstrated as one possible application.
Anomalous Oscillatory Structure in Heat Pulse Diffusion Profiles at a High Power
Authors: Ikari Hiroshi
Published: March 2014

Heat pulse diffusion profiles of thin slabs (0.25 mm thick vitreous silica, crystalline quartz and sapphire) have been measured in liquid helium at 3.33 K. The tail parts of the profiles show anomalous oscillatory structure at a critical high power, which is caused by film boiling at the heater. Around the critical power, the ballistic profiles of 10 mm thick sapphire remain unchanged. It is unusual that the sharp oscillatory structure has been observed in vitreous silica in the same way as crystals. This structure possibly suggests some coherent phonon propagation at high frequency in glass.
Effect of Ultrasonic Vibrations on the Growth of InxGa1-xSb Mixed Crystals
Authors: Tsuruta Takuya , Hayakawa Yasuhiro , Kumagawa Masashi
Published: March 2014

Effects of ultrasonic vibrations were investigated on In
x
Ga1-x
Sb mixed crystals grown by the Czochralski method. During the growth, ultrasonic vibrations were introduced into the melt through the carbon crucible. In
x
Ga1-x
Sb (0<x<0.07) was grown in the single crystalline state to a fair thickness with the introduction of ultrasonic vibrations, but no single crystals were obtained without vibrations. The growth thickness in the single crystalline state was increased with an increase of the output power of ultrasonic vibrations introduced.
Detection of Starved Joints in Plywood by Acoustic Emissions
Authors: Shimotsu Masaki , Kotaki Mitsukazu , Ogasawara Yuji , Yoshimura Noboru , Okuyama Daitaro
Published: March 2014

The automatic evaluatation of the adhesive strength of plywood is beyond the capabilities of methods proposed to date, and development of such a test methods is most important. Detection of starved joints in plywood by acoustic emissions (AE) method was therefore attempted. Test specimens with and without starved joints were prepared of 2-ply plywood. AEs generated from plywood specimens with and without starved joints were measured during the cooling of plywood thermally stressed by a hot press, and AE characteristics of the two kinds of specimens were compared.
Dynamic Analysis of Vapor Bubble in Liquid Using Acoustic Emission Measurement
Authors: Sakurai Kikukazu , Kawaharada Miho , Tsuzuki Mitsuo
Published: March 2014

Acoustic source wave analysis was carried out to examine quantitatively the dynamic motion of a vapor bubble generated on a superheated surface in a liquid. In this analysis, the response function for the transmission medium and the transducer was taken into account, and the source wave was obtained in terms of the pressure-time function through FFT and IFFT. The relationship between the acoustic energy of the source wave and the characteristics of the ink droplet ejection was evaluated for the purpose of applying high pressure vapor bubbles to use in thermal ink jet technology.