bluuebunny/crossref_metadata_2025 huggingface dataset:
Giant Faraday rotation in Cd1–xMnx Te (0 < x < 0.82) crystals
Authors: Hwang Younghun , Chung Soo‐seong , Um Youngho
Published: December 2007

We investigated the magneto‐optical properties of diluted magnetic semiconductors Cd1–x Mnx Te crystals grown using a vertical Bridgman method. This material crystallizes in the zinc‐blende structure for values of x < 0.82. The band‐gap energy was depended on Mn mole fraction x linearly and increased with decreasing temperature. The increase of the energy gap with increasing x may be due to a decrease in the lattice constant. Faraday rotation as a function of photon energy with various Mn compositions for CdMnTe in the temperature range of 10–300 K has been measured. The Faraday rotation was increased as the photon energy increased near to that of the fundamental band gap. Verdet constant becomes larger since the effect of the sp ‐d exchange interaction is enhanced as the temperature is lowered. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magnetic properties of Co/Pt‐Pd multilayer thin film media
Authors: Inaba N. , Igarashi S. , Kirino F. , Fujita F. , Koike K. , Kato H.
Published: December 2007

We investigated the dependence of magnetic properties for Co/Pt100–x Pdx multilayer thin films on the concentration in the Pt‐Pd alloy layers. Perpendicular magneto anisotropy constant Kp increases with increasing Pt concentration in the Pt‐Pd layer, since the interface anisotropy between the Co and the Pt‐Pd layers is enhanced by the increase of the Pt concentration. The Curie temperature and the temperature dependence of Kp for the specimens increase with increasing the amount of Pt in the Pt‐Pd layer. These results may indicate that the lattice distortion of the Co layer caused by the interface from the Pt‐Pd layer becomes larger and the increase of the distortion enhances the interface anisotropy, since the lattice misfit between the Pt‐Pd and the Co increases with increasing the Pt concentration. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigation of sputtered tape media with an ultra‐thin magnetic layer
Authors: Lee Hwan‐Soo , Laughlin David E.
Published: December 2007

Recording characteristics of underlayers (NiAl/CrMn)/intermediate layer (CoCrTa)/CoCrPtBN thin film media sputter‐deposited on polymeric substrates were investigated as functions of the magnetic layer and the stack thicknesses. Even a very small thickness of 10 nm of the magnetic layer appeared to be sufficient to preserve the in‐plane Hc, and gave rise to the improved recording performances due to primarily the sharper effective head field gradient. The thicknees reduction provided benefits in the fabrication side along with presenting a substantial contribution to the overall recording performance. The overall stack thicknees was reduced down to 70 nm. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magnetoelastic properties of nanostructured FeCoSiB ribbons used for high‐sensitive stress sensors
Authors: Thang P. D. , Huong Giang D. T. , Tinh B. C. , Danh T. M. , Tuan N. H. , Duc N. H.
Published: December 2007

High‐sensitive stress sensor is simply constructed comprising magnetostrictive 30 μm‐thick (Fe80Co20)78Si12B10 ribbon acting as a sensitive magnetic core inside an induction coil. The stress can be determined indirectly by measuring the change in the output voltage in the two‐coil system. The results show that the sensitivity highly depends on the intrinsic properties of the ribbon cores. The optimum with both a high sensitivity and an almost linear stress dependence of output signal was obtained in the 250 °C‐annealed ribbon. This is attributed to the correlation between the magnetic and magnetoelastic softness governed by the fine 10 nm nanograin structure. These high sensitivity and simple fabrication sensors are widely applicable to various stress detecting fields. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magnetic and photocatalytic effect of Fe‐doped nano‐rod ZnO synthesized by the hydrolysis of metal powders
Authors: Uum Y. R. , Han B. S. , Lee H. M. , Hong S. M. , Kim G. M. , Rhee C. K.
Published: December 2007

Fe‐doped ZnO nano‐rods have been simply synthesized by a hydrolysis method. The starting Zn and Fe nano‐powders were incorporated into distilled water, and then the solution was refluxed at 60 °C for 24 h to obtain the precipitation of hydroxide gel from the hydrolysis of Zn and Fe. Finally the thermal treatment was carried out at 300 °C for 1 h. X‐ray diffraction patterns for all samples exhibited that the resultant precipitates were completely ZnO powder. The TEM result for Fe‐doped ZnO showed rod shape with diameter of 30nm and length of 300nm. With increasing Fe content up to 2 wt.%, the UV‐vis spectra were shifted to the long wave length and this result indicates that the band gap was shifted by Fe‐doping. Whereas the sample with 5wt.% Fe‐doping showed the ferromagnetic behavior at room temperature, the ferromagnetic properties disappeared at the samples with above 5 wt% Fe‐doping. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigation of magnetization reversal in chains of permalloy ellipses via magnetoresistance measurement and magnetic force microscopy
Authors: Chao C. T. , Ou J. Y. , Chang Y. C. , Chang C. C. , Lee H. M. , Wu J. C.
Published: December 2007

The magnetization reversal processes of single and chained permalloy thin film ellipses were investigated by using magnetoresistance measurements and magnetic force microscopy. The permalloy ellipses with fixed short axis of 1 micrometer and various long axes of 6, 8, 10 micrometers, respectively, were fabricated by standard electron beam lithography through a lift‐off process. It was found that the switching field increases with increasing the long axis of the ellipse in the case of single ellipse. The switching field of two ellipses in series is higher than that of each individual one. The stronger shape anisotropy is accounted for the increasing of switching field in longer element, in which two ellipse in series can be seen as a longer element as a whole. In the case of two identical and a longer ellipses in series, the switching field falls in‐between those two measured on individual shorter and longer ones. Magnetic force microscopy reveals a wavelike domain configuration nucleated during magnetization reversal only in the middle one of three chained ellipses, in which this kind of non‐coherent reversal process may contribute to the decreasing of the switching field. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Research for magnetocaloric effect of Gd1–xDyx alloy
Authors: Hou Xueling , Shitao Li , An Zhang , Hui Xu , Ni Jiansen , Zhou Bangxin
Published: December 2007

The magnetocaloric effect (MEC) in Gd1–xDyx (x = 0.13, 0.20, 0.27, 0.34, 0.40) alloys is investigated using commercial elements with purity of up to 99.80% for Gd and Dy. These alloys are prepared by arc melting in stoichiometric proportions on a water‐cooled copper crucible under high pure argon atmosphere. As a result, when x was changed from 0 to 40at%, the adiabatic temperature change (ΔT) increases from 1.6 K to 3.1 K, the Curie temperature decreased from 288 K to 245.5 K. Gy73Dy27 exhibits the largest ΔTmax value of 3.1 K at the TC value of 260 K among the alloys investigated up to 1.2 T (tesla) applied field, it is almost same as the ΔT of high pure unitary Gd (99.99%) and is clearly superior to commercial unitary Gd (99.80%). The TC of Gy73Dy27 alloy is minor to high pure unitary Gd (99.99%) and commercially unitary Gd (99.80%). But this alloy prepared by commercial elements with low cost has better MEC to be a promising candidate for magnetic working substances for room temperature magnetic refrigeration. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Figures of merit of magneto‐optic spatial light modulators with magnetophotonic crystals
Authors: Takahashi K. , Takagi H. , Shin K. H. , Uchida H. , Lim P. B. , Inoue M.
Published: December 2007

This paper presents the simulated and measured results of two types of one dimensional magnetophotonic crystals (1‐D MPC) with single cavity and dual cavity respectively for applcation to thin film type magneto‐optic spatial light modulators (MOSLMs). The use of MPC is expected to be effective for thin film type MOSLM, because the apparent Faraday rotation is largely enhanced due to light localization in magnetic defect layer of MPC with a large number of periodic dielectric layers. The complex chracteristics of MPCs are discussed in this paper – Faraday rotation θF, transmittance T, and figure of merit F = T sin(2θF). It is key point of finding optimal structure of MPC for application of MOSLM to use F, because the T decreased with increase of k, while Faraday rotation θF increased, indicating that the enhancement of light modulation rate could be achieved by optimizing the figure of merit F defined by F ≈ T ·sin2θF. The maximum F = 13.7 was obtained in dual cavity MPC, while F = 12.5 was obtained in single cavity MPC. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magnetization curves of dipolar coupled nanomagnets
Authors: Mamiya H. , Nakatani I. , Nimori S. , Furubayashi T.
Published: December 2007

Interacting superparamagnet (ISP) model that describes the effects of dipolar coupling on the magnetizing process is examined for assemblies of anisotropic nanomagnets by controlling the coupling strength using two different methods. In the first method, the magnetic moment of each nanomagnet is grown by annealing CoAg nanogranular films. In the second method, the number density of nanomagnets in solidified iron‐nitride magnetic fluids is controlled by the dilution in their melted states. Both the systems show temperature‐independent magnetizing curves at lower temperatures, as predicted by the ISP model. However, in contrast to the prediction, this feature can be primarily attributed not to the dipolar coupling but to magnetic anisotropy of each nanomagnet. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Design of a slim optical image stabilization actuator for mobile phone cameras
Authors: Yu Hsing‐Cheng , Liu T. S.
Published: December 2007

Mechanical optical image stabilization actuator (OISA) will quickly become a standard feature in a high resolution mobile phone camera (MPC) and the quantity of MPC will exceed that of digital still cameras in several years. Whenever jitter arises from shaky hands or environment in taking photos, optical images projected upon an image sensor blur. Designing a slim OISA in MPC is an effective solution that addresses image quality. Therefore, this work presents a slim OISA utilized in MPC to compensate jitter form camera shake in taking photos. Two proportional‐integral‐derivative controllers based on transfer functions for dual axes of the slim OISA system in MPC obtained from system identification have been designed. The settling time of dual axes are less than 0.03 sec. Furthermore, a thrust ball bearing in this study has reduced the friction force between the movable and the stationary parts, so as to minimize the driving current to be less than 5 mA. Hence, the slim OISA has satisfied low power consumption requirement, and is also possible to reduce dimension in the MPC application. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Detection of inverse spin‐Hall effect in palladium
Authors: Harii K. , Ando K. , Sasage K. , Saitoh E.
Published: December 2007

We report that a Pd film exhibits strong inverse‐Spin‐Hall effect (ISHE) at room temperature using the spin pumping operated by ferromagnetic resonance. The intensity of ISHE in Pd was found to be comparable to that in a Pt film. This result indicates an important role of the spin‐orbit scattering in the spin‐Hall effects. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Soft magnetic properties of patterned Co‐based amorphous wires with various dimensions
Authors: Park Chang Bean , Kim Do Hun , Chun Dong Won , Han Jun Hyun , Choi Heon Jin , Jeung Won Young
Published: December 2007

Soft magnetic properties of melt spun Co‐based amorphous wires fabricated by photo lithography and wet etching processes were examined with length (1 ∼ 10 mm), width (200 μm ∼ 6 mm), and thickness (3 ∼ 20 μm) variation. The value of coercivity Hc, susceptibility κ and squareness were extracted from M‐H curve measured using a vibrating sample magnetometer (VSM). Monotonic increase of these values with aspect ratio of the wires was observed, which shows that the magnetic properties of the samples were largely determined by shape anisotropy. The observed phenomena were explained by the competition between domain wall pinning and demagnetizing field. It was shown that, when the sample's residual stress is constant, demagnetizing factor largely determines its magnetic properties. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Research progress on high performance Nd‐Fe‐B permanent magnet
Authors: Li W. , Pan W. , Guo Y. Q. , Guo Z. H. , Zhu M. G. , Li A. H. , Li X. M. , Cui J. W.
Published: December 2007

We have systemically investigated the correlations among magnetic characterization and lattice distortion as well as multiphase couplings during the fabrication process of the high performance Nd‐Fe‐B magnets. Rietveld structural refinement is employed to determine the atomic occupations in every phase in Nd‐Fe‐B magnet. The magnetism of Nd‐Fe‐B was studied with a modified magnetic valence model. It reveals that the magnetic moment only depends on the total number of d and s‐p as well as f electrons, not on the band shape. The coercivity of Nd‐Fe‐B magnet is related to the Nd‐Fe coupling, and its hard magnetic characteristics is derived from the Nd‐B layers. The extra Nd atoms are necessary to be arranged near to the Fe‐Fe layers or Fe atomic clusters for forming Nd‐Fe pairs, which enhances the coercivity. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Novel actuator with flat movable part for optical pickup head
Authors: Ke Chau‐Yuan , Huang Ruey‐Shing
Published: December 2007

In an optical pick‐up head, the objective lens actuator is a key component used to move the objective lens to the exact position for focusing the laser spot on the disc recording layer and keeping the laser spot following certain track on the disc. In order to be used in a compact pick‐up head for high density drives, the objective lens actuator must be compact and controllable in focusing, tracking, and radial tilt directions. In this paper, an electromagnetic three‐axis‐controllable actuator with a novel structure was designed and verified. Magnetic circuit analysis and structural modal analysis were also done in this work. Results of the frequency response tests done with the prototypes corresponded with the simulation results, and the reading tests done by using a pick‐up head with the actuator designed in this work proved the feasibility of this design. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High‐frequency ferromagnetic properties of FeCoZr nanocrystalline films
Authors: Peng Yung‐Wang , Li Shandong , Liu Kai‐Xin , Duh Jenq‐Gong , Yamaguchi Masahiro
Published: December 2007

FeCoZr magnetic thin films with high uni‐axial anisotropy were fabricated by RF co‐sputtering followed by post magnetic annealing. The crystal size of FeCoZr films was less than 15 nm, as calculated by Scherrer equation from X‐ray diffraction patterns. By adding Zr element, FeCoZr films exhibited a uni‐axial anisotropy after magnetic field annealing at 400 °C for 1 hr. Optimal high frequency ferromagnetic properties were achieved in film with 19 at.% Zr, in which strong uni‐axial anisotropy field of 300 Oe and high ferromagnetic resonance frequency in excess of 5.2 GHz were obtained. These facts suggest that FeCoZr nano‐crystalline film is a potential candidate in high frequency electromagnetic devices operating at GHz bands. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Double‐layered microwave absorbers composed of ferrite and carbon fiber composite laminates
Authors: Kim Sun‐Hong , Park Yong‐Gwon , Kim Sung‐Soo
Published: December 2007

Microwave absorbing properties of ferrite‐epoxy composite (absorbing layer) attached on the carbon fiber polymer composite (reflective substrate) are analyzed on the basis of wave propagation theory. A modified equation for wave‐impedance‐matching at the front surface of absorbing layer including the effect of electrical properties of the quasi‐conducting substrate is proposed. Based on this analysis, the frequency and layer dimension that produce zero‐reflection can be estimated from the intrinsic material properties of the absorbing layer and the substrate. It is demonstrated that the microwave reflectivity of carbon fiber composite has a strong influence on the microwave absorbance of front magnetic layer. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nano‐order depth control in magnetic grating
Authors: Maeda Atsushi , Susaki Masami
Published: December 2007

Apodized grating, in which the groove depth was gradually and systematically changed, was carved on the surface of yttrium‐iron‐garnet (YIG) single crystal film by using high‐precision dicing saw. Scanning probe microscope observation indicated that nano‐order modulation was realized in the grating depth as designed. Both of the periodicity and linearity in the grating structure were also controlled well. These experimental results suggest that the mechanical process utilizing the dicing saw is promising as the micro‐fabrication technique with the nano‐order depth control. In comparison with the normal YIG grating filters, the ripples disappeared from the frequency response of the apodized YIG grating filters. The superb propagation characteristics are probably associated with the gentle change in impedance. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Measurement of AC current using an optical fibre sensor
Authors: Cheng C. H. , Chen M. H. , Liu W. F.
Published: December 2007

In the power industry, current is measured for metering and protection purposes. For said measurement, we demonstrated an optical fibre sensor using a single Fibre Bragg Grating (FBG) for measuring AC current for this paper. The sensor head is based on an FBG encased in a polymer‐half‐field metal cylinder, embedded in a magnetic material at the measuring point with the characteristics of an all‐optical high pressure sensitivity. The operating mechanism is that the sensor can be attracted by the induced magnetic force created by the solenoid along one radial direction only, and responds to an axial force on the magnetic rod attached to the round plate, creating an axial attraction on the FBG. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Performance and applications of a small PM generator
Authors: Hwang C. C. , Tien C. L. , Chang H. C.
Published: December 2007

This paper presents a high‐speed low‐power small permanent magnet (PM) generator for aerospace applications where environmental requirements are very severe. Since Alnico magnet material has a low temperature coefficient of remanent flux density and maximum service temperature, it is suitable for the application. Furthermore, the main disadvantage of PM generators is the difficulty of output voltage regulation to compensate for speed and load variation, due to the lack of a simple means of field control. Hence, a circuit is used to connect to the generator to provide a fixed dc voltage to the load. The steady‐state performance is analyzed by the finite element (FE) method. Experimental tests are conducted to verify the FEM predictions. Agreement between FE analysis work and testing results is good. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Correlation between crystal structure and exchange bias of FePt/FeMn multilayers in parallel and perpendicular directions
Authors: Phuoc Nguyen N. , Suzuki Takao
Published: December 2007

A systematic study of parallel and perpendicular exchange biases and blocking temperatures in correlation with the crystal structure of FePt/FeMn multilayers fabricated onto MgO(001) substrates by ion beam sputter‐deposition system was conducted. It was evident that the exchange bias and blocking temperature have a close relation with the formation of the fcc FeMn phase. Besides, the blocking temperature of parallel exchange bias was found to be higher than that of the perpendicular one. The discrepancy was interpreted as due to the spin canting out of plane at the interface. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Current status and future of magnetic heads for HDD
Authors: Terunuma K.
Published: December 2007

The cover picture of this issue of physica status solidi (c) has been taken from the article [1]. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Preface: phys. stat. sol. (c) 4/12
Authors: Lim Sang Ho
Published: December 2007

ISAMMA 2007 was the first consolidated symposium of the three previous symposia held in the Asian region: ISPMM (International Symposium on Physics of Magnetic Materials) of Japan which started in 1987, ISAMT (International Symposium on Spintronics and Advanced Magnetic Technologies) of Taiwan and SOMMA (International Symposium on Magnetic Materials and Applications) of Korea, both of which started in 1999. Considering that there are too many international and domestic meetings around in recent years, I am sure that this kind of consolidation will benefit the people working in magnetics research in the region.

ISAMMA 2007 was held on Jeju island, Korea, during the period 28 May to 1 June 2007. The number of participants was 533 from 26 countries. These statistics clearly indicate that the meeting was truly international! The number of presentations was even higher, there being a total of 613 presentations (174 oral presentations including invited talks and 439 poster presentations). A wide range of subjects were covered in the symposium. The technical sessions included:

– Biomagnetics

– Magnetotransport

– Thin films and multilayers

– Magnetoresistive Random Access Memory (MRAM)

– Nanostructured materials

– Spintronics

– Magnetic oxides and multiferroics

– Magnetic recording and magneto‐optical recording

– Magnetic theory and calculation

– Hard magnetic materials

– Soft magnetic materials

– Magnetic sensors and devices

– Spin dynamics

– Magnetic oxides

The number of manuscripts submitted was approximately 320, among which ∼200 manuscripts were accepted and included in the proceedings. It was a challenging task to deal with such a large number of manuscripts in a short period of time. The formidable task has been completed successfully mainly thanks to the great efforts by the Publication Editors: Dr. Naoki Honda (Akita Research Institute of Advanced Techology, Japan), Prof. Minn‐Tsong Lin (National Taiwan University, Taiwan), Prof. Masahiro Yamaguchi (Tohoku University, Japan), and Prof. Kyung‐Jin Lee (Korea University, Korea). The assignment of reviewers in some sessions was problematic, causing extra burden to the Editors. Due to this and other unexpected problems, the job the editors have done is much beyond the originally anticipated one. My sincere thanks go to you all for your professional service and time, without which the proceedings would have not been issued in the present form. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
QSAR Study of Cyclic Urea Type HIV‐1 PR Inhibitors Using Ab Initio MO Calculation of Their Complex Structures with HIV‐1 PR
Authors: Yoshida Tatsusada , Yamagishi Kenji , Chuman Hiroshi
Published: December 2007

A quantitative structure‐activity relationship study was carried out on a series of cyclic urea type HIV‐1 protease inhibitors. In order to determine the atomic and electronic mechanisms in detail, three‐dimensional and electronic descriptors were calculated with the molecular dynamics and ab initio fragment molecular orbital calculation of the whole complex structure of HIV‐1 protease with each inhibitor. Two descriptors showing correlation with the inhibitory potency were the total interaction energy and the change in the accessible surface area on complex formation with HIV‐1 protease. The major contributions to the total electronic interaction energy were found to be from Asp25/25′, Asp30/30′ and Ile50/50′. The interaction energy with Asp30/30' was nicely correlated with the total electronic interaction energy and also with the charge transfer from Asp30/30′, which is in close contact with the substituted moiety in each inhibitor. As well as the hydrophobic interaction, the charge redistribution among the inhibitor and surrounding residues was suggested to govern the variation in the inhibitory potency. The results obtained in this work can help us to reinterpret the classical QSAR descriptors proposed by Garg et al.
Rescue robots for mudslides: A descriptive study of the 2005 La Conchita mudslide response
Authors: Murphy Robin R. , Stover Sam
Published: December 2007

The Center for Robot‐Assisted Search and Rescue (CRASAR) assisted the Ventura County Fire Rescue Department with the January 2005 La Conchita, California, mudslide response. CRASAR provided commercially available urban search and rescue robots and expert operators which were deployed twice into damaged structures. The waterproof robots were able to tolerate wet conditions but proved unable to handle the densely packed rubble, vegetation, and soil and failed within two and four minutes, respectively on their two deployments. Informal interviews were conducted with responders as well. The experience forms a descriptive study of what mudslide responses are like, what tasks robots are needed for, how the rescue robots performed, and how responders viewed the robots. Our observations are captured in fourteen findings on robot performance (3), domain characteristics of mudslides (8), and general rescue robot design issues (3). These findings are expected to be of interest to robot designers, software developers, and the human‐robot interaction communities. The experience at La Conchita illustrates that terrain understanding, critical for both robot design and for control, remains an important open research question for rescue robotics. © 2008 Wiley Periodicals, Inc.
Evolution and field performance of a rescue robot
Authors: Micire Mark J.
Published: December 2007

Robots are slowly finding their way into the hands of search and rescue groups. One of the robots contributing to this effort is the Inuktun VGTV‐Xtreme series by American Standard Robotics. This capable robot is one of the only robots engineered specifically for the search and rescue domain. This paper describes the adaptation of the VGTV platform from an industrial inspection robot into a capable and versatile search and rescue robot. These adaptations were based on growing requirements established by rescue groups, academic research, and extensive field trials. A narrative description of a successful search of a damaged building during the aftermath of Hurricane Katrina is included to support these claims. Finally, lessons learned from these deployments and guidelines for future robot development is discussed. © 2008 Wiley Periodicals, Inc.
Development of “Souryu‐IV” and “Souryu‐V:” Serially connected crawler vehicles for in‐rubble searching operations
Authors: Arai Masayuki , Tanaka Yoshinori , Hirose Shigeo , Kuwahara Hiroyuki , Tsukui Shingo
Published: December 2007

The authors have developed Souryu‐I, Souryu‐II and Souryu‐III, connected crawler vehicles that can travel in rubble. These machines were developed for the purpose of finding survivors trapped inside collapsed buildings. However, when conducting experiments in post‐disaster environments with Souryu‐III, mechanical and control limitations have been identified. This led the authors to develop novel crawler units using crawler tracks strengthened with metal, and develop two improved models, called Souryu‐IV (composed of three double‐sided crawler bodies, a joint driving unit, a blade‐spring joint mechanism, and cameras) and Souryu‐V (composed of mono‐tread‐crawler bodies, elastic‐rod‐joint mechanisms, and cameras). The authors then conducted basic motion experiments and teleoperated control experiments on off‐road fields with Souryu‐IV and Souryu‐V. Their high performance in experiments of urban rescue operations was confirmed. However, several problems were identified during the driving experiments, and are reported in this paper, as well as a few possible solutions to solve them. This paper describes Souryu‐IV and Souryu‐V, their mechanisms, their cameras, and the experiments to test their mobile performance. © 2008 Wiley Periodicals, Inc.
Assessing the Effect of Surface Chemistry on Gold Nanorod Uptake, Toxicity, and Gene Expression in Mammalian Cells
Authors: Hauck Tanya S. , Ghazani Arezou A. , Chan Warren C. W.
Published: December 2007

Through the use of various layer‐by‐layer polyelectrolyte (PE) coating schemes, such as the common poly(diallyldimethylammonium chloride)–poly(4‐styrenesulfonic acid) (PDADMAC‐PSS) system, the mammalian cellular uptake of gold nanorods can be tuned from very high to very low by manipulating the surface charge and functional groups of the PEs. The toxicity of these nanorods is also examined. Since the PE coatings are individually toxic, the toxicity of nanorods coated in these PEs is measured and cells are found to be greater than 90% viable in nearly all cases, even at very high concentrations. This viability assay may not be a complete indicator of toxicity, and thus gene‐expression analysis is used to examine the molecular changes of cells exposed to PDADMAC‐coated nanorods, which enter cells at the highest concentrations. Indicators of cell stress, such as heat‐shock proteins, are not significantly up‐ or down‐regulated following nanorod uptake, which suggests that PDADMAC‐coated gold nanorods have negligible impact on cell function. Furthermore, a very low number of genes experience any significant change in expression (0.35% of genes examined). These results indicate that gold nanorods are well suited for therapeutic applications, such as thermal cancer therapy, due to their tunable cell uptake and low toxicity.
The Association of Daily Hassles and Uplifts with Family and Life Satisfaction: Does Cultural Orientation make a Difference?
Authors: Lavee Yoav , Ben-Ari Adital
Published: December 2007

The study examined similarities and differences between people having individualist and collectivist cultural orientations in terms of what they perceive as stressful and uplifting experiences in their daily lives, and the relation between daily experiences and family and life satisfaction. Data were collected from two representative community samples (697 Jews and 303 Arabs). Each sample was grouped into individualist and collectivist cultural orientations. The two cultural orientation groups differed with respect to the appraisal of positive and negative daily experiences. A structural equation modeling (SEM) multi‐group analysis indicated a similar factor structure for hassles and uplifts in both groups. However, the two groups differed in the effects of positive and negative daily occurrences on family and life satisfaction.
The generalized Logit-Linear Item Response Model for Binary-Designed Items
Authors: Revuelta Javier
Published: December 2007

This paper introduces the generalized logit-linear item response model (GLLIRM), which represents the item-solving process as a series of dichotomous operations or steps. The GLLIRM assumes that the probability function of the item response is a logistic function of a linear composite of basic parameters which describe the operations, and the coefficients depend on three design matrices X, Y and Z. The GLLIRM provides a tool for testing hypotheses on the item-solving process and generalizes existing models. An empirical application is included, in which the model is applied to evaluate sources of difficulty and pairwise item interactions in a logical analysis test.
Capturing Proteins that Bind Polyunsaturated Fatty Acids: Demonstration Using Arachidonic Acid and Eicosanoids
Authors: Brock Thomas G.
Published: December 2007

Polyunsaturated fatty acids (PUFA) and their biological derivatives, including the eicosanoids, have numerous roles in physiology and pathology. Although some eicosanoids are known to act through receptors, the molecular actions of many PUFA remain obscure. As the three‐dimensional structure of eicosanoids allows them to specifically bind and activate their receptors, we hypothesized that the same structure would allow other proteins to associate with PUFA and eicosanoids. Here, we demonstrate that biotinylation of arachidonic acid and its oxygenated derivatives 5‐hydroxyeicosatetraenoic acid (5‐HETE) and leukotriene (LT) B4 can be used to pull down associated proteins. Separation of proteins by two‐dimensional gel electrophoresis indicated that a large number of proteins bound each lipid and that proteins could distinguish between two enantiomers of 5‐HETE. Individual proteins, identified by matrix assisted laser desorption/ionization‐time of flight mass spectrometry, included proteins that are known to bind lipids, including albumin and phosphatidylethanolamine‐binding protein, as well as several novel proteins. These include cytoskeletal proteins, such as actin, moesin, stathmin and coactosin‐like protein, and G protein signaling proteins, such as Rho GDP dissociation inhibitor 1 and nucleoside diphosphate kinase B. This method, then, represents a relatively simple and straightforward way to screen for proteins that directly associate with, and are potentially modulated by, PUFA and their derivatives.
Primary Hypercholesterolemia, Carotid Atherosclerosis and Insulin Resistance Among Chinese
Authors: Chien Kuo‐Liong , Liau Chiau‐Suong , Chen Ming‐Fong , Lee Yuan‐Teh , Jeng Jiann‐Shing , Hwang Bao‐Show , Su Ta‐Chen
Published: December 2007

We investigated the genetic contributions to carotid atherosclerosis and insulin resistance in Chinese patients with primary hypercholesterolemia. A family study of probands from the outpatient clinics in patients with high low‐density‐lipoprotein cholesterol levels was conducted. A total of 62 families (360 subjects) underwent carotid ultrasonography and insulin resistance measurement. The correlation coefficients of carotid intima‐media thickness (IMT) were high among spouse, parent–offspring, and sibling pairs (0.39, 0.38 and 0.35, respectively). All insulin indices and IMT had significant estimates of heritability, of which fasting insulin had the highest heritability (0.410 ± 0.104, P = 0.0001), followed by homeostasis model assessment (HOMA) (0.395 ± 0.108, P = 0.0001). The estimated heritability of IMT was significant (0.185 ± 0.103, P = 0.025) but not of plaque score. Bivariate genetic coefficient between IMT and HOMA was 0.569 ± 0.292, while the environmental coefficient was 0.028 ± 0.103. The study confirms a relationship between insulin resistance and atherosclerosis and, in particular, between insulin resistance and the thickening of the arterial wall. Moreover, it shows that genetics influence both insulin resistance and atherosclerosis, implying that the management of insulin resistance may benefit the prevention of atherosclerotic disease in familial hypercholesterolemia.
Obtaining Butter Oil Triacylglycerols Free from β‐Carotene and α‐Tocopherol via Activated Carbon Adsorption and Alumina‐Column Chromatography Treatments
Authors: Karabulut Ihsan , Topcu Ali , Akmil‐Basar Canan , Onal Yunus , Lampi Anna‐Maija
Published: December 2007

It is difficult to remove β‐carotene from oils with alumina‐column chromatography, because β‐carotene is even less‐polar than triacylglycerols (TAGs) are. The objective of this study was to obtain butter oil TAGs free from β‐carotene and antioxidants via sequential treatments with activated carbon (AC) adsorption and alumina column chromatography. The AC used was prepared from waste apricots. The effects of AC dosages, temperatures and time courses on β‐carotene adsorption were studied. The Langmuir and Freundlich isotherms were used to describe the adsorption of β‐carotene onto AC, and it was found to be more consistent with the Freundlich isotherm with a higher R2 value (0.9784). Adsorption kinetics of β‐carotene was analyzed by pseudo‐first order and pseudo‐second order models. The pseudo‐second order model was found to explain the kinetics of β‐carotene adsorption more effectively (R2 = 0.9882). The highest β‐carotene reduction was achieved (from 31.9 to 1.84 mg/kg) at an AC dosage of 10 wt%, temperature of 50 °C, and adsorption time of 240 min. A considerable amount of α‐tocopherol was also adsorbed during the AC treatment. Remaining portions of α‐tocopherol were completely removed with alumina adsorption chromatography. The method described may be used for purification of vegetable oil TAGs, which will be used as model compounds in model oxidation studies.
Effect of Processing Conditions on the Crystallization Behavior and Destabilization Kinetics of Oil‐in‐Water Emulsions
Authors: Martini Silvana , Tippetts Megan
Published: December 2007

The objective of this research was to systematically study the effect of processing conditions on the crystallization behavior and destabilization mechanisms of oil‐in‐water emulsions. The effect of crystallization temperature (Tc) and homogenization conditions on both thermal behavior and destabilization mechanisms were analyzed. Results show that the crystallization of lipids present in the emulsions was inhibited when compared with bulk lipids as evidenced by a lower onset and peak temperature (Ton and Tp, respectively) in differential scanning calorimetry crystallization exotherms. The smaller the droplet size in the emulsion, the more significant the inhibition (lower Ton and Tp). Lower values of Ton and Tp were not necessarily indicators of emulsion stability. Homogenization conditions not only affected the Ton and Tp of crystallization but also the crystallization profile of the samples. Lipids present in emulsions with small droplets were crystallized and melted in a less fractionated manner when compared to lipids in bigger droplets or even to the bulk lipids. The amount of lipid crystallized as evidenced by enthalpy values, did not have a direct relationship with the emulsions stability. Although enthalpy values increased as Tc decreased, the destabilization kinetics did not follow the same tendency as evidenced by back scattering measurements.
Clonal turnover of MACE-carrying peach-potato aphids (Myzus persicae (Sulzer), Homoptera: Aphididae) colonizing Scotland
Authors: Kasprowicz L. , Malloch G. , Foster S. , Pickup J. , Zhan J. , Fenton B.
Published: December 2007

Peach-potato aphids, Myzus persicae (Sulzer), collected in Scotland in the years 1995 and 2002–2004 were characterized using four microsatellite loci and three insecticide resistance mechanisms. From 868 samples, 14 multilocus genotypes were defined (designated clones A–N). Five of these (denoted A, B, H, M and N) carried modified acetylcholinesterase (MACE) resistance, the most recent resistance mechanism to have evolved in M. persicae. The current paper shows that the continued presence of MACE aphids is due to turnover, as clones A and B were replaced in field samples by clones H, M and N in later seasons. Thus, insecticide-resistant populations in Scotland can be attributed to multiple waves of rapid clone colonisations and not to the continued presence of stable resistant clones or mutation or sexual recombination in local populations. The MACE clones carried varying levels of the other insecticide resistance mechanisms, kdr and esterase. The presence of these mechanisms could alter the clones success in the field depending on insecticide spraying (positive selection) and resistance fitness costs (negative selection).
The Economic Aftermath of the 1960s Riots in American Cities: Evidence from Property Values
Authors: Collins William J. , Margo Robert A.
Published: December 2007

In the 1960s many American cities experienced violent, race-related civil disturbances. This article examines census data from 1950 to 1980 to measure the riots' impact on the value of central-city residential property, and especially on black-owned property. Both OLS and IV estimates indicate that the riots depressed the median value of black-owned property between 1960 and 1970, with little or no rebound in the 1970s. Census tract data for a small number of cities suggest relative losses of population and property value in tracts that were directly affected by riots compared to other tracts in the same cities.
Lost Decades: Postindependence Performance in Latin America and Africa
Authors: Bates Robert H. , Coatsworth John H. , Williamson Jeffrey G.
Published: December 2007

Africa and Latin America secured independence from European colonial rule a century and half apart: most of Latin America by the 1820s and most of Africa by 1960. Despite the distance in time and space, they share important similarities. In each case independence was followed by political instability, violent conflict, and economic stagnation lasting for about a half-century. The parallels suggest that Africa might be exiting from a period of postimperial collapse and entering one of relative political stability and economic growth, as did Latin America almost two centuries ago.
The Impact of Globalization in the Roman Empire, 200bc—ad100
Authors: Geraghty Ryan M.
Published: December 2007

The article employs a general equilibrium model to describe Italy's response to commodity and factor market integration during the expansion of the Roman Empire. This novel approach constructs a comprehensive story of the Italian economy that corroborates established developments and sheds light on controversial and unanswered questions. The success of the model supports arguments that Romans were rational economic actors and that the Roman economy was a well-integrated market system.
Local thermal non-equilibrium effects arising from the injection of a hot fluid into a porous medium
Authors: REES D. ANDREW S. , BASSOM ANDREW P. , SIDDHESHWAR PRADEEP G.
Published: December 2007

We examine the effect of local thermal non-equilibrium on the infiltration of a hot fluid into a cold porous medium. The temperature fields of the solid porous matrix and the saturating fluid are governed by separate, but coupled, parabolic equations, forming a system governed by three dimensionless parameters. A scale analysis and numerical simulations are performed to determine the different manners in which the temperature fields evolve in time. These are supplemented by a large-time analysis showing that local thermal equilibrium between the phases is eventually attained. It is found that the thickness of the advancing thermal front is a function of the governing parameters rather than being independent of them. This has the implication that local thermal equilibrium is not equivalent to a single equation formulation of the energy equation as might have been expected. When the velocity of the infiltrating fluid is sufficiently large, the equations reduce to a hyperbolic system and a thermal shock wave is formed within the fluid phase. The strength of the shock decays exponentially with time, but the approach to local thermal equilibrium is slower and is achieved algebraically in time.
Nonlinear evolution, travelling waves, and secondary instability of sheared-film flows with insoluble surfactants
Authors: HALPERN DAVID , FRENKEL ALEXANDER L.
Published: December 2007

The nonlinear development of the interfacial-surfactant instability is studied for the semi-infinite plane Couette film flow. Disturbances whose spatial period is close to the marginal wavelength of the long-wave instability are considered first. Appropriate weakly nonlinear partial differential equations (PDEs) which couple the disturbances of the film thickness and the surfactant concentration are obtained from the strongly nonlinear lubrication-approximation PDEs. In a rescaled form each of the two systems of PDEs is controlled by a single parameter C, the ‘shear-Marangoni number’. From the weakly nonlinear PDEs, a single Stuart–Landau ordinary differential equation (ODE) for an amplitude describing the unstable fundamental mode is derived. By comparing the solutions of the Stuart–Landau equation with numerical simulations of the underlying weakly and strongly nonlinear PDEs, it is verified that the Stuart–Landau equation closely approximates the small-amplitude saturation to travelling waves, and that the error of the approximation converges to zero at the marginal stability curve. In contrast to all previous stability work on flows that combine interfacial shear and surfactant, some analytical nonlinear results are obtained. The Hopf bifurcation to travelling waves is supercritical for C < Cs and subcritical for C > Cs, where Cs is approximately 0.29. This is confirmed with a numerical continuation and bifurcation technique for ODEs. For the subcritical cases, there are two values of equilibrium amplitude for a range of C near Cs, but the travelling wave with the smaller amplitude is unstable as a periodic orbit of the associated dynamical system (whose independent variable is the spatial coordinate). By using the Bloch (‘Floquet’) disturbance modes in the linearized PDEs, it transpires that all the small-amplitude travelling-wave equilibria are unstable to sufficiently long-wave disturbances. This theoretical result is confirmed by numerical simulations which invariably show the large-amplitude saturation of the disturbances. In view of this secondary instability, the existence of small-amplitude periodic solutions (on the real line) bifurcating from the uniform flow at the marginal values of the shear-Marangoni number does not contradict the earlier conclusions that the interfacial-surfactant instability has a strongly nonlinear character, in the sense that there are no small-amplitude attractors such that the entire evolution towards them is captured by weakly-nonlinear equations. This suggests that, in general, for flowing-film instabilities that have zero wavenumber at criticality, the saturated disturbance amplitudes do not always have to decrease to zero as the control parameter approaches its value at criticality.
Influence of insoluble surfactant on the deformation and breakup of a bubble or thread in a viscous fluid
Authors: HAMEED M. , SIEGEL M. , YOUNG Y.-N. , LI J. , BOOTY M. R. , PAPAGEORGIOU D. T.
Published: December 2007

The influence of surfactant on the breakup of a prestretched bubble in a quiescent viscous surrounding is studied by a combination of direct numerical simulation and the solution of a long-wave asymptotic model. The direct numerical simulations describe the evolution toward breakup of an inviscid bubble, while the effects of small but non-zero interior viscosity are readily included in the long-wave model for a fluid thread in the Stokes flow limit.

The direct numerical simulations use a specific but realizable and representative initial bubble shape to compare the evolution toward breakup of a clean or surfactant-free bubble and a bubble that is coated with insoluble surfactant. A distinguishing feature of the evolution in the presence of surfactant is the interruption of bubble breakup by formation of a slender quasi-steady thread of the interior fluid. This forms because the decrease in surface area causes a decrease in the surface tension and capillary pressure, until at a small but non-zero radius, equilibrium occurs between the capillary pressure and interior fluid pressure.

The long-wave asymptotic model, for a thread with periodic boundary conditions, explains the principal mechanism of the slender thread's formation and confirms, for example, the relatively minor role played by the Marangoni stress. The large-time evolution of the slender thread and the precise location of its breakup are, however, influenced by effects such as the Marangoni stress and surface diffusion of surfactant.