bluuebunny/crossref_metadata_2025 huggingface dataset:
Same Phase Drive Type Ultrasonic Motors
Authors: Tomikawa Yoshiro , Takano Takehiro , Toda Kohji
Published: March 2014

This paper deals with some new ultrasonic motors of same phase drive type. First, a flexural disk ultrasonic motor using its two degenerate resonant modes, but not accompanied with rotation of them, is investigated. This motor has such a special merit that a small sized power source is enough to excite the motor because of using only one channel of electrical input. Secondly, same type ultrasonic motor using a single resonant mode of a flexural ring vibrator is studied. Experimental results have proved that the motors dealt with could produce relatively high thrust under not so much electrical power.
SAW Propagation Characteristics on Piezoelectric Layer/Diamond Substrate Structure
Authors: Yamamoto Shin-ichi , Tani Atsushi , Gounji Takashi
Published: March 2014

An A/N layer/Diamond substrate structure has been introduced to achieve production using present fabrication techniques of SAW devices for use in the 5 to 10 GHz band. The propagation characteristics have been analyzed. For the third Rayleigh wave, a phase velocity of 10,000 m/s or more in a wide A/N layer range and the coupling coefficient of more than 0.1% were obtained, thus meeting our requirements. The third Rayleigh wave of the A/N/SiO2/Diamond structure has also been analyzed in an attempt to simplify production of A/N layer. Satisfactory results were obtained assuming that the SiO2 layer thickness is 10% of that of A/N.
Reaction Mechanism and Dielectric Properties in the Pb(Mg1/2W1/2)O3–Pb(Ni1/3Nb2/3)O3–PbTiO3 System
Authors: Takahashi Seiji , Ochi Atsushi , Utsumi Kazuaki , Shirakata Masato
Published: March 2014

The effects of sample preparation conditions on dielectric properties of ceramics in the Pb(Mg1/2W1/2)O3–Pb(Ni1/3Nb2/3)O3–PbTiO3 system were investigated. The dielectric constant of this ceramic depended on the mixing condition of the raw powders, particularly. It was found to be lower when starting powders were poorly mixed than when they were properly mixed. This was attributed to the presence of a small amount of a Pb–W–O compound formed during preparation of dielectric powder when the mixing was insufficient. By increasing mixing time, the amount of Pb–W–O compound was decreased and the dielectric constant was increased.
Drive Voltage Dependence of Electromechanical Resonance in PLZT Piezoelectric Ceramics
Authors: Uchino Kenji , Negishi Hiroyasu , Hirose Terukiyo
Published: March 2014

Drive voltage dependence of electromechanical resonance has been investigated in PLZT piezoelectric ceramics. With increasing the ac drive voltage, some electromechanical parameters change remarkably: the resonance frequency f
m decreases, the anti-resonance frequency f
n does not shift, the mechanical quality factor Q
m decreases drastically, and the electromechanical coupling factor k
r increases. On the contrary, these parameters do not change significantly with changing the dc bias voltage, keeping the ac voltage amplitude. The changes in the parameters can be computer-simulated theoretically by introducing non-linear capacitive and resisitive terms into an electrical equivalent circuit.
Microstructure of Pb(Zr0.53Ti0.43)O3 Ceramic Synthesized by Partial Oxalate Method (Using Zr0.53Ti0.47O2 Hydrothermal Produced Powder as a Core of Pb(Zr0.53Ti0.47)O3)
Authors: Yamamoto Takashi , Tanaka Ryouji , Okazaki Kiyoshi , Ueyama Tamotsu
Published: March 2014

Pb(Zr0.53Ti0.47)O3 powder was produced by partial oxalate method using Zr0.53Ti0.47O2 powder which was derived by hydrothermal processing. The Pb(Zr0.53Ti0.47)O3 ceramics was sintered at fairly low temperature. This synthesized process was discussed with microstructures of powder and ceramics. The Zr0.53Ti0.47O2 hydrothermal produced powder was estimated to be a core of reaction.
Optics of Recording and Read-out in Optical Disk Systems
Authors: Braat Joseph
Published: March 2014

Successful read-out of digital optical disks largely depends on the system tolerances, e.g., with respect to defocusing. Different read-out schemes (integral detection and confocal detection) are treated and the corresponding tolerance range is discussed.
Garnet Films for Magneto-Optical Recording
Authors: Itoh Akiyoshi
Published: March 2014

This paper reviews the state of the art of garnet films for megneto-optical recording applications. The effects of impurity doping such as Ba, B, and P and heat treatment conditions during fabrication of the films by pyrolysis were reported. The maximum C/N of the film fabricated by pyrolysis on glass was 49 dB. Doping with B or P decreased the rate of crystallization and Ba was effective to rise coercive force of the film. Surface morphology of the films were observed and low temperature heat treatment was effective to have smooth surface.
Polarizing Grating Beamsplitter Using a Liquid Crystal Cell
Authors: Lehureau J. C. , Beguin J. Y. , Colineau J.
Published: March 2014

We show how a grated liquid crystal cell may be used for separating the reflected beam from the incident beam in an optical disc pick-up. The high polarizing efficiency of this beamsplitter allows the realization at low cost of optical pickup for write once and magnetooptic disc. Additional features may be implemented in the grating design in order to obtain easily the radial and focusing error signals. Furthermore the liquid crystal cell may have additional functions such as quarterwave plate for write once applications or electrically controllable compensation plate for magnetooptic applications.
We tested a prototype head using knife edge focusing sensor and push-pull radial sensor. The four quadrant detector is placed beneath the laser chip. All components of the pick-up with exception of the objective lens could be easily integrated in the laser case.
A New Flying Optical Head
Authors: Yasukawa K. , Yamaguchi S. , Murakami A. , Goto H. , Nishimura N. , Ueyanagi K.
Published: March 2014

A new flying optical head was developed for attaining the high speed accessing. The weight of the moving part of the flying optical head is reduced to less than 10 gr by using the flying slider. The variation of distance between an objective lens and a disk is largely reduced by floating the objective lens on the disk surface. The autofocusing is done by axially moving one of the relay lenses, which is mounted on the fixed part of the head. The moving part is carried by a linear motor to do track-following as well as track-seeking. The mechanical resonant frequency for the linear motor is as high as more than 5 kHz, and it can sufficiently follow disk tracks under the condition of the radial runout of ±45 µm and the rotational speed of 1800 rpm. The new flying optical head is successfully applied for read/write of optical disk data.
Low Energy Excitation Modes of Amorphous Polymers and Structural Relaxation at Low Temperatures Probed by PHB
Authors: Furusawa Akira , Horie Kazuyuki , Mita Itaru
Published: March 2014

Low energy excitation modes of amorphous linear and crosslinked polymers coupled with the photoreactive molecules and the temperature dependence of Debye-Waller factor for various chromophore/amorphous polymer matrix systems are estimated from PHB measurements. The requisites for high temperature hole formation are also discussed.
Photochemical Hole Burning in Highly Doped TPP/PMMA Systems. Energy Migration and Stabilization of Burnt Holes for Subsequent Hole-Burnings
Authors: Suzuki Hiroyuki , Shimada Toshiyuki , Nishi Toshihiro , Hiratsuka Hiroaki
Published: March 2014

Photochemical hole-burning experiments were performed on highly doped TPP/PMMA systems. Kinetics of the photophysical processes which compete with the PHB photochemistry, including the interguest energy migration, was analyzed. Reduction of the hole-filling efficiency accompanied by subsequent hole-burning was observed when ZnTPP was also incorporated in the system. Applicability of highly doped host-guest systems to the practical PHB optical memory was discussed.
A Possibility of Application of Photo-Etching of a-C:H Films to Relief Holograms
Authors: Irie Makoto , Kouzu Noriyuki , Kuramochi Yoshimi , Iida Seishi , Sakuda Kyohei
Published: March 2014

Amorphous C:H films prepared by glow discharge decomposition of C3H8 were found to exhibit thickness decrease under UV light exposure. Corresponding relation between the decrease of EPMA carbon signal intensity and the decreased amount of film thickness showed that this decrease was caused by photo-etching under UV light exposure. The estimated resolving power of this phenomenon is high enough to construct surface relief holograms. Direct formation of two beam interference relief holograms using an UV He–Cd laser has been tried for the first time. The photographed images reconstructed by a He–Ne laser (633 nm) and an Ar+ laser (488 nm) were shown to hold the diffraction relation and to give the correct value of grating period expected for optical configuration used at hologram recording. These results present confirmative evidence that the relief hologram was really constructed in the a-C:H film. Together with other experimental results, some discussions are given for an application of the film for high resolution write-once recording medium.
The Interface Wall Structure of Magnetic Triple-Layer Film for Overwriting by Light Intensity Modulation
Authors: Kaneko Masahiko , Aratani Katsuhisa , Mutoh Yoshihiro , Nakaoki Ariyoshi , Watanabe Kenjirou , Makino Hiroshi
Published: March 2014

The direction of the spin in the interface wall of magnetic double-layer and triple-layer films has been calculated using the variation method. The calculation as well as experimental results have shown that the interface wall of magnetic double-layer film is unstable in most cases unless it is supported by the applied magnetic field, while the wall in magnetic triple-layer film is stabilized at the intermediate layer. In addition to the stability of its wall, triple-layer film has been found to have advantages for overwriting by light intensity modulation in that the initializing field is as small as 2.5 kOe and the total magnetic layer thickness is only 1200 A.
High Speed Transformations in Phase-Change Optical Recording Media
Authors: Jung Ai-Lien , Situ Huo , Ye Qian-Qing , Wang Zhi-Tao , He Zhi-Gang , Xie Jun , Yu Hong-Tao , Zhang Zhong-Lin , Shi Li-Qing , Zhao Jing , Li Xiao-Bai
Published: March 2014

Characteristics of erasable phase-change optical recording media: SbTe-, SbSe-, InTe-, InSe- and GeTe-based thin films and their two binary compounds are reviewed, with particular focus on stability and fast reversibility. We first report that the photo-crystallization dominates in optical recording media since the time required for the transformation is much less than that for the pure thermal crystallization. When photo-crystallization is taken into account, the activation energy for crystallization, Δ
E, in J-M-A equation should be replaced by an effective activation energy ΔE
eff which is equal to ΔE-\hbarw. This substitution will suffice to explain the high speed crystallization, i.e. photo-crystallization.
Direct Overwrite in Magneto-Optical Recording Technology
Authors: Kryder M. H. , Schultz M. D.
Published: March 2014

Progress on implementing direct overwrite in magneto-optical recording is reviewed.
Observations made with a 10 nsec exposure time magneto-optic camera system show that in single-layer media in which a constant bias field may be used for writing and erasing, circular domains erase by a collapse process. Observations made on stripe erasure show that erasure proceeds most easily from the end of the stripe. Experiments with high-speed scanning indicate that both circular domains and stripes may be overwritten at scanning speeds at least as high as 15 m/sec.
Three techniques for achieving direct overwrite with these single-layer media are described. The single-beam technique utilizes only a single laser beam with a modulated power level to achieve direct overwrite. Because stripes are easier to erase from the ends, this technique may require restricted modulation codes in which two ones are separated by no more than one zero such as the (1, 7) code. The erase-before-write technique uses two beams through a single lens. The first beam erases any previously written data on the track and the second writes the new data. This technique requires no restriction on modulation codes and also prevents interactions between the previously existing data and the new data. The read-before-overwrite technique requires that the previously written data be read and selectively altered to produce the new data pattern. Because of the added complexity of the electronics, this is the least favored technique.
The single-beam and erase-before-write techniques compare favorably with respect to approaches using field modulation or exchange-coupled multilayers, because both the head and media are relatively simple. On the other hand, data reported thus far in the literature indicate the best carrier-to-noise ratio is obtained with field modulation. Since research is still underway in a number of laboratories, the reported CNR, for all techniques are likely to improve, however.
Modeling the Magneto-Optic Recording Process
Authors: Perlov C. M. , Birecki H.
Published: March 2014

A theoretical model for domain formation in magneto-optic media is presented. Model results are compared to experimental data on a disk with known optical and thermal properties. Application of the model to the magneto-optic data channel is discussed.
Magneto-Optical Recording in Co/Pt Multilayers
Authors: Greidanus F. J. A. M. , Zeper W. B. , Jacobs B. A. J. , Spruit J. H. M. , Carcia P. F.
Published: March 2014

In this paper the magnetic and magneto-optical properties as well as the recording performance of Co/Pt layered structures are described. Two different structures are investigated: One with 4 Å Co and 9 Å Pt layers and the other with 4 Å Co and 18 Å thick Pt layers. We show with Lorentz microscopy that very regular domains can be written in these layers and we relate these results to the measured recording performance. Domain patterns are written in two different ways, with laser modulation (LM) and magnetic field modulation (MFM). With LM very regularly shaped domains are formed. With MFM we find a strong tendency for subdomain formation.
A Write-Once Optical Card Reader/Writer Using Two Optical Sources
Authors: Yoda Shigeru , Tsutsui Keiichi , Koshiba Yoshihito , Tsuboi Kazuo , Tsuji Michio , Yamashita Tsukasa
Published: March 2014

An optical card has many advantages such as portability, large storage capacity, and low cost. We have developed an optical card reader/writer using two optical sources: a laser diode (LD) for writing and an LED for reading. We have demonstrated that this method is effective for stable and high speed reading/writing because of (1) wide tracking dynamic range, (2) stable data reading signal vs. tracking error, (3) no card damage by reading light, (4) two track reading, and (5) direct read during write.
Boosting the Opportunities of Open Learning (MOOCs) through Learning Theories
Authors: Fasihuddin Heba A. , Skinner Geoff D. , Athauda Rukshan I.
Published: March 2014

The recent evolution of computing technology has led to dramatic developments and changes in online learning. Open learning is a new form of online learning that allows learning materials to be freely available on the Internet and accessible to anyone who is interested. Different initiatives, which are based on the open learning concept, have been initiated by various prestigious institutions. Although all of these initiatives provide courses with free access to content, each has its own approach in terms of teaching, assessment and even their own goals of defining an open learning environment. Massive Open Online Courses is the term for courses provided in these open environments. These courses attract a large number of learners, however their success and efficacy in terms of the learning process has yet to be determined. The authors found that there is no clear model for open learning environments and therein lies our research objective. Many aspects still need to be considered and addressed in order to achieve a reliable and sustainable model. These aspects can be addressed with consideration to the principles of cognitive science so that better learning models can be obtained. This paper presents some learning theories that can be considered and applied to enhance open learning environments. The use of knowledge maps, as an approach to implement schema theory, was selected to present and organize the learning concepts. In addition, the Felder-Silverman learning styles theory was selected to personalize the learning environment and provide learning materials based on every learner’s needs and preferences.
Preparation and characterization of 2‐methacryloyloxyethyl phosphorylcholine polymer nanofibers prepared via electrospinning for biomedical materials
Authors: Maeda Tomoki , Hagiwara Katsuya , Yoshida Soki , Hasebe Terumitsu , Hotta Atsushi
Published: March 2014

Electrospun nanofibers of poly (2‐methacryloyloxyethyl phosphorylcholine) (MPC) possessing excellent hemocompatibility were successfully fabricated first. These nanofibers were investigated as drug‐delivery vehicles for suppressing the acute thrombogenicity of vascular grafts to lower the risk of coronary artery disease by improving the graft patency rate; the graft patency rate is the percentage of patients who do not have any blockage in a graft after a stent‐graft treatment. We varied the MPC concentrations in ethanol from 1 to 10 wt % to fabricate electrospun MPC fibers. Scanning electron microscopy images revealed that when the MPC concentration was lower than 5 wt %, beads instead of fibers were formed. When the MPC concentration was increased (>5 wt %), uniform fibers were produced with average fiber diameters of about 160 nm (5 wt %), 640 nm (7.5 wt %), and 1270 nm (10 wt %). In vitro drug‐release tests showed that a higher amount of drugs was diffused from MPC fibers with small diameters; this indicated a faster drug‐release rate for the thinner MPC fibers. Diameter‐controlled MPC fibers could be used as a new vascular graft materials. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40606.
The likelihood of death from prostate cancer in men with favorable or unfavorable intermediate‐risk disease
Authors: Keane Florence K. , Chen Ming‐Hui , Zhang Danjie , Loffredo Marian J. , Kantoff Philip W. , Renshaw Andrew A. , D'Amico Anthony V.
Published: March 2014

BACKGROUND

Recently, men with intermediate‐risk prostate cancer (PC) were classified into favorable and unfavorable categories; however, whether the risk of PC‐specific mortality (PCSM) among men with high‐risk PC versus unfavorable intermediate‐risk PC is increased is unknown.

METHODS

In a prospective, randomized trial conducted between 1995 and 2001, 206 men with intermediate‐risk or high‐risk PC were randomized to receive 70 Gy with or without 6 months of androgen‐suppression therapy (AST). The subgroup of 197 patients with information available on the percentage of positive biopsies formed the cohort. Fine and Gray regression analysis was used to assess whether men with high‐risk PC versus unfavorable intermediate‐risk PC had an increased risk of PCSM.

RESULTS

After a median follow‐up of 14.3 years, there were 127 deaths (64.5%), including 22 deaths (17.3%) from PC. There were no PC deaths in the favorable intermediate‐risk group. There was an increase in the risk of PCSM among men with high‐risk PC versus unfavorable intermediate‐risk PC, but the difference was not significant (adjusted hazard ratio, 1.59; 95% confidence interval, 0.66‐3.83; P = .30) after adjusting for age, randomized treatment arm, and comorbidity.

CONCLUSIONS

The lack of PC deaths among men with favorable intermediate‐risk PC suggests that adding AST may not reduce their risk of PCSM; whereas many men with unfavorable intermediate‐risk PC are at risk for harboring occult PC with Gleason scores from 8 to 10 and, if proven, would benefit from long‐term AST. Multiparametric magnetic resonance imaging and targeted biopsy of suspicious lesions should be considered to identify PC with Gleason scores from 8 to 10 in these men. Cancer 2014;120:1787–1793. © 2014 American Cancer Society.
Interference‐aware MAC scheduling and admission control for multiple mobile WBANs used in healthcare monitoring
Authors: Mahapatro Judhistir , Misra Sudip , Mahadevappa Manjunatha , Islam Nabiul
Published: March 2014

In this paper, we address the problem of interference when multiple time division multiple access‐based wireless body area networks (WBANs) come in the proximity of one another. We propose a simple solution that creates common non‐conflicting schedule between these interfering WBANs. Our proposed scheme allows the reuse of maximum possible time slots among WBANs that are two‐hop neighbors of one another. A flow admission control scheme is applied to control the flows during the period of interference. We show that the percentage of flows admitted because of flow control decreases with the increase in the network size and flow rate. We simulated a scenario where WBANs move randomly within a simulation area with a certain speed and meet at a particular point. We show that the signal to interference noise ratio (SINR) value of WBANs changes as long as they are within the transmission range of one another. Also, we show that the exchanges of common schedule (which is dependent on the number of times the SINR value drops below the threshold) are required in order to improve the packet delivery ratio in WBANs. Copyright © 2014 John Wiley & Sons, Ltd.
Influence of an electromagnetic field on the bioreduction of chromium (VI) using a mixed culture of microorganisms
Authors: de Oliveira Moura Alex Anderson , Terra Natália Mazzarioli , da Silva Borges Wesley , Xavier Costa Ernane José , Cardoso Vicelma Luiz , de Resende Miriam Maria
Published: March 2014

In this study, the bioreduction of chromium (VI) and Chemical Oxygen Demand (COD) were obtained using a mixed culture of microorganisms originating from the tannery industry. The influence of an electromagnetic field on the reduction of chromium (VI), together with the removal of COD and total chromium, were evaluated. Batch reactors were used, one in the presence of an electromagnetic field and another without exposure to the field. The bioreduction was conducted with various initial concentrations of chromium (VI) (50, 100, 150, and 200 mg L−1) at different electromagnetic field frequencies (1, 2, 5, and 10 Hz) with different initial volumes of the effluent (300, 500, and 1000 mL). Using an initial concentration of chromium (VI) of 100 mg L−1 in 500 mL of effluent at a frequency of 5 Hz, the maximum chromium (VI) bioreduction was 100% after 8 h, but the total removal of chromium was 38%. Using the same conditions but with a volume of 1000 mL, the same reduction of chromium (VI) was achieved, but there was a need for a longer processing time, ∼14 h. When using concentrations above 100 mg L−1, the same efficiency for the bioreduction of chromium (VI) was not obtained relative to the experiments performed without the presence of an electromagnetic field. The concentration of cells in both reactors remained almost constant over time, except when a frequency higher than 5 Hz was used, where we could observe the occurrence of cell death. © 2014 American Institute of Chemical Engineers Environ Prog, 34: 88–98, 2015
Analysis of 14 years of broadband ground‐based solar UV index observations in Barcelona
Authors: Bech J. , Sola Y. , Ossó A. , Lorente J.
Published: March 2014

This study presents an analysis of a 14‐year data set of 30‐min averaged experimental UVI values derived from ground‐based broadband irradiance measurements, satellite‐derived total ozone observations and total solar radiation recorded in Barcelona (NE Spain). Most maximum daily UVI values do occur at noon (82% of cases between 11:30 and 13:00 UTC). Considering all seasons, the maximum daily UVI presents a bimodal, approximately symmetrical, frequency distribution with a maximum around UVI class 2 (22%) and UVI 7 and 8 classes (23%) while June median presents a value of 8.2. According to attenuation criteria there is a preponderance of Clear sky days (77%) compared to Broken (22%) and Overcast (8%) conditions, which concentrate mostly in October, November and December (reaching 20% of days). An additional classification in terms of World Health Organisation UVI intensity categories indicates that 40% of days exceeded the Lower threshold of UVI category Moderate (UVI values above 5.5), from them 21% of days had UVI values considered Very High (above 9.5) and one single case was classified as Extreme (UVI above 10.5). UVI values above 7.5 were found under Broken sky conditions in June, July and August. Additionally UVI diurnal daily cycles have also been analyzed in terms of selected percentile values and maximum levels. Under all sky conditions UVI median values exceed the lower threshold of category High (5.5) from April to late August around noon (in June from 10:00 to 14:30 UTC). These results provide an exhaustive quantitative description of average and extreme values of experimental UVI values observed in the region and can be of interest for a wide range of applications, including ground‐based UV modelling through the use of radiative transfer models, trend analysis or verification of UVI forecasts.
Development and application of an analytical method using gas chromatography/triple quadrupole mass spectrometry for characterizing alkylated chrysenes in crude oil samples
Authors: John G. F. , Yin F. , Mulabagal V. , Hayworth J. S. , Clement T. P.
Published: March 2014

RATIONALE

Recent advances in analytical techniques have led to the development of gas chromatography/triple quadrupole mass spectrometry methods that allow the identification of target analytes in complex environmental samples. We have employed this technology to develop a method for characterizing alkylated chrysenes, which are environmental toxins that are resistant to weathering.

METHODS

An Agilent 7890 gas chromatograph coupled to an Agilent 7000B triple quadrupole mass spectrometer was used. The mass spectral fragmentation of seven commercially available alkylated chrysene standards was studied under full‐scan and product‐ion scan conditions. The calibration curves used were in the linear range with r2 values greater than 0.99. The recovery and limit of detection of target analytes in the samples were in the range of 80–120% and 0.11–1.09 ng/mL, respectively.

RESULTS

The information inferred from full‐scan and product‐ion scan data was combined with literature data to develop a GC/MS/MS method for the identification and quantification of C1‐, C2‐, C3‐, and C4‐chrysene homologues. The method was employed to characterize MC252 crude oil which was released during the 2010 Deepwater Horizon accident. The results showed that the chrysene concentrations estimated by the proposed method were well within the range of previously reported values.

CONCLUSIONS

The proposed method is useful for analyzing chrysene and its alkylated homologues in crude oil samples. Copyright © 2014 John Wiley & Sons, Ltd.
Modeling the intracellular organization of calcium signaling
Authors: Dupont Geneviève
Published: March 2014

Calcium (Ca2+) is a key signaling ion that plays a fundamental role in many cellular processes in most types of tissues and organisms. The versatility of this signaling pathway is remarkable. Depending on the cell type and the stimulus, intracellular Ca2+ increases can last over different periods, as short spikes or more sustained signals. From a spatial point of view, they can be localized or invade the whole cell. Such a richness of behaviors is possible thanks to numerous exchange processes with the external medium or internal Ca2+ pools, mainly the endoplasmic or sarcoplasmic reticulum and mitochondria. These fluxes are also highly regulated. In order to get an accurate description of the spatiotemporal organization of Ca2+ signaling, it is useful to resort to modeling. Thus, each flux can be described by an appropriate kinetic expression. Ca2+ dynamics in a given cell type can then be simulated by a modular approach, consisting of the assembly of computational descriptions of the appropriate fluxes and regulations. Modeling can also be used to get insight into the mechanisms of decoding of the Ca2+ signals responsible for cellular responses. Cells can use frequency or amplitude coding, as well as take profit of Ca2+ oscillations to increase their sensitivity to small average Ca2+ increases.

This article is categorized under:

Models of Systems Properties and Processes > Cellular Models

Biological Mechanisms > Cell Signaling
A starch‐binding domain identified in α‐amylase (AmyP) represents a new family of carbohydrate‐binding modules that contribute to enzymatic hydrolysis of soluble starch
Authors: Peng Hui , Zheng Yunyun , Chen Maojiao , Wang Ying , Xiao Yazhong , Gao Yi
Published: March 2014

A novel starch‐binding domain (SBD) that represents a new carbohydrate‐binding module family (CBM69) was identified in the α‐amylase (AmyP) of the recently established alpha‐amylase subfamily GH13_37. The SBD and its homologues come mostly from marine bacteria, and phylogenetic analysis indicates that they are closely related to the CBM20 and CBM48 families. The SBD exhibited a binding preference toward raw rice starch, but the truncated mutant (AmyPΔSBD) still retained similar substrate preference. Kinetic analyses revealed that the SBD plays an important role in soluble starch hydrolysis because different catalytic efficiencies have been observed in AmyP and the AmyPΔSBD.
The Economics of Climate Change
Authors: Stern Nicholas
Published: March 2014

There is now clear scientific evidence that emissions from economic activity, particularly the burning of fossil fuels for energy, are causing changes to the Earth´s climate. A sound understanding of the economics of climate change is needed in order to underpin an effective global response to this challenge. The Stern Review is an independent, rigourous and comprehensive analysis of the economic aspects of this crucial issue. It has been conducted by Sir Nicholas Stern, Head of the UK Government Economic Service, and a former Chief Economist of the World Bank. The Economics of Climate Change will be invaluable for all students of the economics and policy implications of climate change, and economists, scientists and policy makers involved in all aspects of climate change.
Design, Optimization and Fabrication of a 28.3 THz Nano-Rectenna for Infrared Detection and Rectification
Authors: Gadalla M. N. , Abdel-Rahman M. , Shamim Atif
Published: March 2014

The increasing energy demands of the world's population and the quickly diminishing fossil fuel reserves together suggest the urgent need to secure long-lasting alternative and renewable energy resources. Here, we present a THz antenna integrated with a rectifier (rectenna) for harvesting infrared energy. We demonstrate a resonant bowtie antenna that has been optimized to produce highly enhanced localized fields at the bow tip. To benefit from this enhancement, the rectifier is realized between the overlapped antenna's arms using a 0.7 nm copper oxide. The thin film diode offers low zero bias resistance of 500 Ω, thus improving the impedance matching with the antenna. In addition, the rectenna prototype demonstrates high zero bias responsivity (4 A/W), which is critical in producing DC current directly from THz signals without the application of an external electric source, particularly for energy harvesting applications.
Photoinduced electron transfer across molecular bridges: electron- and hole-transfer superexchange pathways
Authors: Natali Mirco , Campagna Sebastiano , Scandola Franco
Published: March 2014

A tutorial review outlining a general conceptual framework, based on superexchange, to discuss the role of chemical bridges in photoinduced electron transfer processes.
The important role of the Mo–Mo quintuple bond in catalytic synthesis of benzene from alkynes. A theoretical study
Authors: Chen Yue , Sakaki Shigeyoshi
Published: March 2014

The reaction mechanism of catalytic synthesis of benzene from alkynes by the Mo–Mo quintuple bond and the electronic structure and bonding nature of dimetallacyclobutadiene and dimetallabenzyne were studied theoretically.
Colloidal nickel/gallium nanoalloys obtained from organometallic precursors in conventional organic solvents and in ionic liquids: noble-metal-free alkyne semihydrogenation catalysts
Authors: Schütte Kai , Doddi Adinarayana , Kroll Clarissa , Meyer Hajo , Wiktor Christian , Gemel Christian , van Tendeloo Gustaaf , Fischer Roland A. , Janiak Christoph
Published: March 2014

The Hume-Rothery phase NiGa as nanoparticles in an ionic liquid is a recyclable catalyst for selective semihydrogenation with yields of about 90% and selectivities of up to 94%.
Directional Counter for the Determination of the Complete Azimuthal Effect of Primary Cosmic Radiation
Authors: Baños alfredo , Perusquía M. L.
Published: March 2014

The apparatus which the authors designed, constructed, and operated at the Institute of Physics of the National University of Mexico for the purpose of determining the azimuthal variation of primary cosmic radiation at fixed zenith angles consists essentially of four triple-coincidence Geiger-Müller telescopes mounted at zenith angles of 0°, 20°, 40°, and 60°, and are so arranged that, by rotation around a vertical axis, the directional intensity or counting rate can be measured at 16 equally spaced azimuths. The rotation and photographic recording are fully automatic. Several novel features of the apparatus are discussed here, most notable of which is the feature that, in contradistinction to the usual parallel connection of the three counters, as used in the conventional Rossi circuit and necessitating an amplifier tube for each Geiger-Müller counter, a material simplification of the circuits was obtained by connecting the three counters in series feeding a single stage of amplification.
State observers and Kalman filtering for high performance vibration isolation systems
Authors: Beker M. G. , Bertolini A. , van den Brand J. F. J. , Bulten H. J. , Hennes E. , Rabeling D. S.
Published: March 2014

There is a strong scientific case for the study of gravitational waves at or below the lower end of current detection bands. To take advantage of this scientific benefit, future generations of ground based gravitational wave detectors will need to expand the limit of their detection bands towards lower frequencies. Seismic motion presents a major challenge at these frequencies and vibration isolation systems will play a crucial role in achieving the desired low-frequency sensitivity. A compact vibration isolation system designed to isolate in-vacuum optical benches for Advanced Virgo will be introduced and measurements on this system are used to present its performance. All high performance isolation systems employ an active feedback control system to reduce the residual motion of their suspended payloads. The development of novel control schemes is needed to improve the performance beyond what is currently feasible. Here, we present a multi-channel feedback approach that is novel to the field. It utilizes a linear quadratic regulator in combination with a Kalman state observer and is shown to provide effective suppression of residual motion of the suspended payload. The application of state observer based feedback control for vibration isolation will be demonstrated with measurement results from the Advanced Virgo optical bench suspension system.
Structure and magnetic properties of low-temperature phase Mn-Bi nanosheets with ultra-high coercivity and significant anisotropy
Authors: Liu Rongming , Zhang Ming , Niu E , Li Zhubai , Zheng Xinqi , Wu Rongrong , Zuo Wenliang , Shen Baogen , Hu Fengxia , Sun Jirong
Published: March 2014

The microstructure, crystal structure, and magnetic properties of low-temperature phase (LTP) Mn-Bi nanosheets, prepared by surfactant assistant high-energy ball milling (SA-HEBM) with oleylamine and oleic acid as the surfactant, were examined with scanning electron microscopy, X-ray diffraction, and vibrating sample magnetometer, respectively. Effect of ball-milling time on the coercivity of LTP Mn-Bi nanosheets was systematically investigated. Results show that the high energy ball milling time from tens of minutes to several hours results in the coercivity increase of Mn-Bi powders and peak values of 14.3 kOe around 10 h. LTP Mn-Bi nanosheets are characterized by an average thickness of tens of nanometers, an average diameter of ∼1.5 μm, and possess a relatively large aspect ratio, an ultra-high room temperature coercivity of 22.3 kOe, a significant geometrical and magnetic anisotropy, and a strong (00l) crystal texture. Magnetization and demagnetization behaviors reveal that wall pinning is the dominant coercivity mechanism in these LTP Mn-Bi nanosheets. The ultrafine grain refinement introduced by the SA-HEBM process contribute to the ultra-high coercivity of LTP Mn-Bi nanosheets and a large number of defects put a powerful pinning effect on the magnetic domain movement, simultaneously. Further magnetic measurement at 437 K shows that a high coercivity of 17.8 kOe and a strong positive temperature coefficient of coercivity existed in the bonded permanent magnet made by LTP Mn-Bi nanosheets.
Study of the interaction of solutes with Σ5 (013) tilt grain boundaries in iron using density-functional theory
Authors: Jin Hao , Elfimov Ilya , Militzer Matthias
Published: March 2014

Substitutional alloying elements significantly affect the recrystallization and austenite-ferrite phase transformation rates in steels. The atomistic mechanisms of their interaction with the interfaces are still largely unexplored. Using density functional theory, we determine the segregation energies between commonly used alloying elements and the Σ5 (013) tilt grain boundary in bcc iron. We find a strong solute-grain boundary interaction for Nb, Mo, and Ti that is consistent with experimental observations of the effects of these alloying elements on delaying recrystallization and the austenite-to-ferrite transformation in low-carbon steels. In addition, we compute the solute-solute interactions as a function of solute pair distance in the grain boundary, which suggest co-segregation for these large solutes at intermediate distances in striking contrast to the bulk.
A multi-scale controlled tissue engineering scaffold prepared by 3D printing and NFES technology
Authors: Yan Feifei , Liu Yuanyuan , Chen Haiping , Zhang Fuhua , Zheng Lulu , Hu Qingxi
Published: March 2014

The current focus in the field of life science is the use of tissue engineering scaffolds to repair human organs, which has shown great potential in clinical applications. Extracellular matrix morphology and the performance and internal structure of natural organs are required to meet certain requirements. Therefore, integrating multiple processes can effectively overcome the limitations of the individual processes and can take into account the needs of scaffolds for the material, structure, mechanical properties and many other aspects. This study combined the biological 3D printing technology and the near-field electro-spinning (NFES) process to prepare a multi-scale controlled tissue engineering scaffold. While using 3D printing technology to directly prepare the macro-scaffold, the compositing NFES process to build tissue micro-morphology ultimately formed a tissue engineering scaffold which has the specific extracellular matrix structure. This scaffold not only takes into account the material, structure, performance and many other requirements, but also focuses on resolving the controllability problems in macro- and micro-forming which further aim to induce cell directed differentiation, reproduction and, ultimately, the formation of target tissue organs. It has in-depth immeasurable significance to build ideal scaffolds and further promote the application of tissue engineering.
Mechanisms of macroaggregate stabilisation by carbonates: implications for organic matter protection in semi-arid calcareous soils
Authors: Fernández-Ugalde Oihane , Virto Iñigo , Barré Pierre , Apesteguía Marcos , Enrique Alberto , Imaz María J. , Bescansa Paloma
Published: March 2014

Carbonates interfere with soil aggregation in semi-arid calcareous soils, promoting the stability of macroaggregates and decelerating the decomposition of the organic matter within them. Our aim was to determine the process through which carbonates participate in aggregation. We hypothesised (i) a tendency to accumulate reactive clay minerals via Ca2+ bridging, and (ii) a precipitation of carbonates within aggregates due to dissolution/re-precipitation phenomena. The <250-µm fractions of a Typic Calcixerept (CALC) and a decarbonated Calcic Haploxerept (DECALC) were incubated from the same agricultural field in semi-arid Spain with added maize straw during 28 days. A size-based fractionation was used to separate different aggregates in incubated and field-moist samples, and aggregates were analysed for organic C and maize-derived C, clay mineralogy by X-ray diffraction, and micromorphology in digital images of thin sections. Contrary to the first hypothesis, the two soils showed a similar tendency to accumulate smectite in aggregates, probably because the cation exchange capacity was saturated by Ca2+ in both CALC and DECALC. Macroaggregates showed a less porous structure in CALC than in DECALC due to the accumulation of calcite microcrystals, as formulated in the second hypothesis. We propose that low porosity of macroaggregates is mainly responsible for the slower turnover of organic matter observed in CALC than in DECALC. These results explain the greater concentration of organic C in microaggregates within macroaggregates in field-moist samples in CALC than in DECALC. The different porosity of macroaggregates may also result in differences in physical properties between CALC and DECALC. These observations suggest a different response of calcareous soils in terms of organic matter protection, resistance to erosion, and water storage compared with other soil types in semi-arid lands.
Nuclear pore complex evolution: a trypanosome Mlp analogue functions in chromosomal segregation but lacks transcriptional barrier activity
Authors: Holden Jennifer M. , Koreny Ludek , Obado Samson , Ratushny Alexander V. , Chen Wei-Ming , Chiang Jung-Hsien , Kelly Steven , Chait Brian T. , Aitchison John D. , Rout Michael P. , Field Mark C.
Published: March 2014

The nuclear pore complex (NPC) has dual roles in nucleocytoplasmic transport and chromatin organization. In many eukaryotes the coiled-coil Mlp/Tpr proteins of the NPC nuclear basket have specific functions in interactions with chromatin and defining specialized regions of active transcription, whereas Mlp2 associates with the mitotic spindle/NPC in a cell cycle–dependent manner. We previously identified two putative Mlp-related proteins in African trypanosomes, TbNup110 and TbNup92, the latter of which associates with the spindle. We now provide evidence for independent ancestry for TbNup92/TbNup110 and Mlp/Tpr proteins. However, TbNup92 is required for correct chromosome segregation, with knockout cells exhibiting microaneuploidy and lowered fidelity of telomere segregation. Further, TbNup92 is intimately associated with the mitotic spindle and spindle anchor site but apparently has minimal roles in control of gene transcription, indicating that TbNup92 lacks major barrier activity. TbNup92 therefore acts as a functional analogue of Mlp/Tpr proteins, and, together with the lamina analogue NUP-1, represents a cohort of novel proteins operating at the nuclear periphery of trypanosomes, uncovering complex evolutionary trajectories for the NPC and nuclear lamina.
Haloactinopolyspora alkaliphila sp. nov., and emended description of the genus Haloactinopolyspora
Authors: Zhang Yong-Guang , Liu Qing , Wang Hong-Fei , Zhang Dao-Feng , Zhang Yuan-Ming , Park Dong-Jin , Kim Chang-Jin , Li Wen-Jun
Published: March 2014

A facultatively alkaliphilic actinomycete strain, designated EGI 80088T, was isolated from a saline-alkali soil sample from Xinjiang province, north-west China, and subjected to a polyphasic taxonomic characterization. Strain EGI 80088T formed fragmented aerial hyphae and short spore chains, and rod-like spores aggregated at maturity. Whole-cell hydrolysates of the isolate contained ll-diaminopimelic acid as the diagnostic diamino acid, and glucosamine, mannose, galactose, glucose and rhamnose as the marker sugars. The major fatty acids identified (>5 %) were anteiso-C15 : 0, iso-C15 : 0, summed feature 4 (iso-C17 : 1I/anteiso-C17 : 1B), iso-C16 : 0 and anteiso-C17 : 0. The predominant menaquinone was MK-9(H4). The G+C content of the genomic DNA of strain EGI 80088T was 70.6 mol%. EGI 80088T showed the highest 16S rRNA gene sequence similarity to its closest phylogenetic neighbour

Haloactinopolyspora alba

YIM 93246T (98.5 %). The DNA–DNA relatedness value of the strain EGI 80088T and

H. alba

YIM 93246T was 59.3±5.2 %. On the basis of morphological, chemotaxonomic and phylogenetic characteristics and DNA–DNA hybridization data, strain EGI 80088T represents a novel species of the genus

Haloactinopolyspora

, for which the name Haloactinopolyspora alkaliphila sp. nov. (type strain EGI 80088T = BCRC 16946T = JCM 19128T) is proposed. The description of the genus

Haloactinopolyspora

has also been emended.
Graduate students' perceptions of supply chain skills for supply chain managers
Authors: Rahman Shams , Qing Nie
Published: March 2014

Purpose

– The aim of this research is to identify the relevant skills and their relative importance, required by supply chain managers, and to suggest the key skill items that require improvement.

Design/methodology/approach

– Using a survey questionnaire, data were collected against 41 supply chain management skills. Using expert opinion, these skill items were then grouped to create four higher level supply chain skill-categories. These are supply chain general management (SCG) skill-category, supply chain analytical (SCA) skill-category, supply chain information technology (SCIT) skill-category, and supply chain environmental-related (SCE) skill-category. Subsequently, the importance-performance matrix (IPM) analysis was conducted to these higher level skill-categories to assess the strengths and weaknesses of the offered skills as perceived by the respondents.

Findings

– The analysis revealed that in order to prepare supply chain managers to face up to the future challenges educational institutions are required to devote their attention on areas such as warehousing management, distribution planning, demand forecasting, negotiation skill, cross-functional coordination skill, and knowledge of environmental issues in supply chains.

Originality/value

– This research provided insight into skills need for supply chain managers using IPM analysis. The results of the study could be adopted to upgrade the existing logistics and supply chain management program or design new logistics education and training programs to meet the current and future needs.