bluuebunny/crossref_metadata_2025 huggingface dataset:
Small printed meander symmetrical and asymmetrical antenna performances, including the RF cable effect, in the 315 MHz frequency band
Authors: Rabinovich Victor , Al‐Khateeb Basim , Oakley Barbara , Alexandrov Nikolai
Published: June 2006

An easily manufactured, reduced size, symmetrical printed meander dipole antenna for remote keyless entry (RKE) automotive applications in the 315 MHz frequency band is proposed. The efficiency and directionality of this symmetrical antenna is estimated and compared with the efficiency and directionality of an asymmetrical antenna. Numerical and experimental results are presented. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1828–1833, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21790
A novel wideband microstrip‐fed elliptical slot array antenna for Ku‐band applications
Authors: Angelopoulos Evangelos S. , Anastopoulos Argyris Z. , Kaklamani Dimitra I. , Alexandridis Antonis A. , Lazarakis Fotis , Dangakis Kostas
Published: June 2006

This study presents a broadband microstrip slot array structure with a novel feeding technique, which offers enhanced bandwidth and very low cross‐polarization levels, targeting the satellite reception application market in the Ku‐Band. The single element module and the antenna array formulations of two, four, and eight elements are examined, fabricated, and experimentally characterized. Details of the design procedure and experimental results are discussed. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1824–1828, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21791
The design of printed rectangular slot antenna with a small isosceles triangle slot for Wimax applications
Authors: Chen Wen‐Shan , Kao Bao‐Hung
Published: June 2006

Printed rectangular slot antenna fed by a 50‐Ω microstrip line with a small isosceles triangle slot for broadband operation is presented. Both impedance and radiation characteristics of this antenna are studied. Experimental results indicate that a 1:2 VSWR bandwidth of 3.97 GHz is achieved at operating frequencies around 1.85–5.83 GHz. By the proposed design, the broadband property and excellent impedance matching lead to practical performance that are good radiation patterns and antenna gain. The design of the proposed antenna is suitable for Wimax applications, which cover the band of 2.495–2.69, 3.4–3.8, and 5.25–5.85 GHz. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1821–1824, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21792
Material reflector for cellular/PCS array applications
Authors: Lee K. W. , Rojas R. G.
Published: June 2006

A material reflector composed of a metallic ground plane, resistive sheets and, if necessary, elongated rails along the edges of the sheet reflector is presented. The optimized design achieves a front‐to‐back ratio greater than 30 dB with minimal change in pattern beamwidth. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1890–1894, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21793
Effective constitutive parameters of structured chiral metamaterials
Authors: Ouchetto O. , Zouhdi S. , Razek A. , Miara B.
Published: June 2006

In this paper we present a novel procedure for predicting the effective constitutive parameters of three‐dimensional periodic materials with chiral component phases. The method combines the mathematical homogenization technique and the finite element method. The homogenization is accomplished by solving a local problem in the unit cell. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1884–1886, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21795
Radiation phenomena from pseudochiral cylinders at plane wave incidence
Authors: Polewski Michael , Lech Rafal , Mazur Jerzy
Published: June 2006

The influence of pseudochiral medium on the scattering patterns of cylindrical pseudochiral objects is presented. Combination of an extended iterative scattering procedure and the orthogonal expansion method is used to investigate multiple cylindrical obstacles. The far scattered field patterns as well as transmission characteristics of rectangular waveguides are presented for different configurations of pseudochiral and isotropic obstacles. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1880–1884, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21796
Electromagnetic wave scattering by a set of axially symmetric Ω‐medium cylinder
Authors: Lech Rafal , Kowalczyk Piotr , Mazur Jerzy
Published: June 2006

This paper presents the analysis of electromagnetic field scattering by a set of cylindrical objects made of pseudochiral material located in rectangular waveguide junctions and free space. Presented approach is based on the iterative scattering procedure (ISP) and the orthogonal expansion method. Several numerical examples for open and closed problems were presented. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1876–1880, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21797
Direct time domain solution for dielectric structure with time derivatives of the potential functions by central difference
Authors: Lee Wonwoo , Sarkar Tapan K.
Published: June 2006

In this article, we presented a new direct time domain solution for three‐dimensional arbitrarily shaped dielectric structures. To solve the time domain electric field integral equation (EFIE), a central differencing scheme is used to evaluate the time derivatives of the potential functions. The solution method is based on the method of moments (MoM) and marching‐on‐in‐time (MOT) technique. An implicit method with the time derivative evaluated by central difference is described to solve the EFIE, and the detailed mathematical procedures are included along with representative numerical results. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1795–1801, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21799
Equivalence between substrate‐integrated (SIRW) rectangular waveguide short‐circuit load and its equivalent rectangular waveguide short‐circuit load
Authors: Che Wenquan , Xu Lei , Wang Dapeng , Geng Liang , Deng Kuan , Chow Y. L.
Published: June 2006

Substrate integrated rectangular waveguide (SIRW) is an artificial rectangular waveguide (RW) constructed in planar substrate with two rows of periodic metallized posts or slots. In this letter, the equivalence formula between the locations of the corresponding short circuits by cylinder walls and by the solid wall was derived, based on the former width equivalence formula of the SIRW and its equivalent RW [(11)]]. The theoretical and simulation results are given for the SIRW short load and RW short load, good agreements have been observed. Such equivalences are convenient for the design of small waveguides, of millimeter wave, in a multilayer circuit structure, such as the LTCC etc. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1694–1698, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21805
Return loss of three types of arching bond wire structures for RF and microwave circuit applications
Authors: Chen Hsing‐Yi , Tai Chen‐Hsien
Published: June 2006

The S‐parameters of a gold wire bonded in air to two microstrip lines are validated by measurements and HFSS software simulations at frequencies of 0.04–6 GHz. From simulation results and measurement data, it is found that an arching bond wire with a smaller arc angle can minimize the return loss. From simulations, it is also found that the return loss can be improved, and operation frequency shifts can be achieved by using multiple wires placed in parallel in bond wire arrays. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1701–1704, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21807
Compact broadband circularly polarized microstrip antenna
Authors: Zhang Jun‐Wen , Zhong Shun‐Shi , Xu Sai‐Qing
Published: June 2006

A compact broadband circularly polarized (CP) microstrip antenna is proposed, in which a square patch printed on the dielectric substrate is fed by a Wilkinson power divider through two orthogonal H‐shaped slots. Comparing with the conventional broadband CP antenna with an air or foam layer, the size of this antenna is reduced significantly and its fabrication is easier. The 10 dB return loss bandwidth of 45.9% and 2 dB axial‐ratio CP bandwidth of 17% were measured. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1730–1732, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21808
Phase verification of compact multilayered low temperature co‐fired ceramic composite right‐/left‐handed transmission line
Authors: Rajab Khalid Z. , Mittra Raj , Lanagan Michael
Published: June 2006

A novel compact multilayered composite right‐/left‐handed (CRLH) transmission line (TL), fabricated using low‐temperature cofired ceramic (LTCC) technology, is demonstrated. In common with the conventional planar CRLH lines, the signal in the multilayered CRLH TL propagates along a defined path; however with the use of parallel‐plate capacitors to create the series capacitances and loop inductors to create the shunt inductances, the size of the TL is significantly reduced compared to that of the planar CRLH TL. Phase‐portraits in the near‐field region as well as far‐field patterns are used to verify the operation in both the left‐ and the right‐handed frequency regions. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1792–1795, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21809
1H and 13C NMR assignments and X‐ray structures for three monocyclic benzoannelated dilactam polyethers
Authors: Smith Gary L. N. , Alguindigue Susan S. , Khan Masood A. , Powell Douglas R. , Taylor Richard W.
Published: June 2006

Three monocyclic polyether dilactams, 17,18‐dihydro‐5H, 9H‐dibenzo[e,n]1,4,10,7,13trioxadiazacyclopentadecine‐6,10(7H,11H)‐dione (1); 9,10,20,21‐tetrahydro‐5H, 12H‐dibenzo[e,q]1,4,10,13,7,16tetraoxadiazacyclooctadecine‐6, 13(7H,14H)‐dione (2); and 6,7,9,10‐tetrahydro‐16H, 20H‐dibenzo[h,q]1,4,7,13, 10,16tetraoxadiazacyclooctadecine‐17, 21(18H,22H)‐dione (3) were isolated during the synthesis of several benzoannelated cryptands. The complete assignments of the 1H and 13C NMR spectra of 1, 2 and 3 in CDCl3 were made using gCOSY, gHMBC, gHMQC, HMQC, HSQC, and NOESY 1D techniques. The ortho (H2) benzene protons show significant downfield shifts (1.16–1.43 ppm) that are consistent with an exodentate orientation for the amide carbonyl groups. The X‐ray crystal structures of 1, 2 and 3 show that the carbonyl groups adopt an exodentate conformation in the solid state. Copyright © 2006 John Wiley & Sons, Ltd.
Hyperactivation of monkey spermatozoa is triggered by Ca2+ and completed by cAMP
Authors: Ishijima Sumio , Mohri Hideo , Overstreet James W. , Yudin Ashley I.
Published: June 2006

Digital image analysis of the flagellar movements of cynomolgus macaque spermatozoa hyperactivated by caffeine and cAMP was carried out to understand the change in flagellar movements during hyperactivation. The degree of flagellar bending increased remarkably after hyperactivation, especially at the base of the midpiece. Mainly two beating patterns were seen in the hyperactivated monkey sperm flagella: remarkably asymmetrical flagellar bends of large amplitude and relatively symmetrical flagellar bends of large amplitude. The asymmetrical bends were often seen in the early stage of hyperactivation, whereas the symmetrical bends executed nonprogressive, figure‐of‐eight movement. Beat frequency of the hyperactivated spermatozoa significantly decreased while wavelength of flagellar waves roughly doubled. To determine the conditions under which the axonemes of hyperactivated sperm flagella have asymmetrical or symmetrical bends, the plasma membranes of monkey spermatozoa were extracted with Triton X‐100 and motility was reactivated with MgATP2− under various conditions. The asymmetrical flagellar bends were brought about by Ca2+, whereas the symmetrical flagellar bends resulted from low levels of Ca2+ and high levels of cAMP. Under these conditions, beat frequency and wavelength of flagellar waves of demembranated, reactivated spermatozoa were similar to those of the hyperactivated spermatozoa. These results suggest that during hyperactivation of monkey spermatozoa intracellular Ca2+ concentrations first rise, and then decrease while cAMP concentrations increase simultaneously. Mol. Reprod. Dev. 1129–1139, 2006. © 2006 Wiley‐Liss, Inc.
Induction of meiotic maturation in mouse oocytes by adenosine analogs
Authors: Downs Stephen M. , Chen Jing
Published: June 2006

In this study we have examined the meiosis‐inducing influence of adenosine analogs in mouse oocytes. When a varied group of nucleosides and nucleotides were tested on overnight cultures of hypoxanthine‐arrested, cumulus cell‐enclosed oocytes (CEO), halogenated adenosine nucleosides, but not native adenosine, exhibited a significant meiosis‐inducing capability. When tested under a variety of conditions, meiotic induction by 8‐bromo‐adenosine (8‐Br‐Ado) and a second adenosine analog, methylmercaptopurine riboside (MMPR), was especially potent in denuded oocytes (DO) compared to CEO and was not dependent on the type of inhibitor chosen to maintain meiotic arrest. Germinal vesicle breakdown (GVB) was stimulated with rapid kinetics and was preceded by an increase in AMP‐activated protein kinase (AMPK) activity. Moreover, compound C, an inhibitor of AMPK, blocked the meiosis‐inducing activities of both adenosine analogs. When tested for an effect on meiotic progression to metaphase II (MII) in spontaneously maturing CEO, 8‐Br‐Ado and the AMPK activator, 5‐aminoimidazole‐4‐carboxamide 1‐β‐D‐ribofuranoside (AICAR), increased the percentage of MII‐stage oocytes, but MMPR decreased this number. Adenosine and inhibitors of de novo purine synthesis had no effect on the completion of maturation, while compound C suppressed this process. These results support the proposition that oocyte AMPK mediates the positive influence of AICAR and 8‐Br‐Ado on both the initiation and completion of meiotic maturation. The role of AMPK in MMPR action is less clear. Mol. Reprod. Dev. 1159–1168, 2006. © 2006 Wiley‐Liss, Inc.
Molecular cloning and characterization of SRG‐L, a novel mouse gene developmentally expressed in spermatogenic cells
Authors: Ma Quanhong , Wang Haikun , Guo Rui , Wang Huizhen , Ge Yehua , Ma Jing , Xue Shepu , Han Daishu
Published: June 2006

Full‐length cDNA of a novel mouse gene upregulated in late stages of spermatogenic cells was cloned from mouse testis using overlapping RT‐PCR and RACE. The mRNA of the gene was expressed mainly in diplotene/pachytene spermatocytes, round and elongating spermatids. We named this gene as SRG‐L (Spermatogenesis Related Gene expressed in late stages of spermatogenic cells, GenBank Accession No. AY352586). The tissue‐specific analysis showed a higher expression level in testis and spleen. The gene is mapped on chromosome 8q33.1 and contains 18 exons. The full‐length of cDNA is 2,843 bp with an open reading frame (ORF) of 2,625 bp that encodes a 104 kDa protein (874 amino acids) with a putative transmembrane region. The bioinformatics analysis revealed that the SRG‐L has two conserved regions, transglutaminase‐like homologues domain and D‐serine dehydratase domain, rich phosphorylation sites and methylation sites. The SRG‐L protein was detected in diplotene/pachytene spermatocytes and spermatids by immunohistochemical staining and Western blot. The results suggest that SRG‐L may play definite roles regulating differentiation of germ cells during spermatogenesis, particularly during meiosis and spermiogenesis. Mol. Reprod. Dev. 1075–1083, 2006. © 2006 Wiley‐Liss, Inc.
Adenylyl cyclases in oocyte maturation: A characterization of AC isoforms in bovine cumulus cells
Authors: Lastro Michele , Collins Sarah , Currie W. Bruce
Published: June 2006

Mammalian oocytes are arrested at the G2/M transition in the meiotic cell cycle. It is well known that a decrease in intraoocyte cAMP concentrations accompanies resumption of meiosis, but the precise trigger of this decrease remains a mystery. Follicular somatic cells are intimately coupled to the oocyte and are thought to transmit maturation signals to the oocyte in response to hormonal stimulation. Here, we investigate the nature of the follicular somatic cell response to hormonal stimulation by identifying and characterizing the adenylate cyclase isoforms present in bovine cumulus cells. RT‐PCR and Western blot analysis revealed the presence of multiple adenylyl cyclase isoforms in bovine granulosa and cumulus cells. Pharmacological manipulation of the AC isoforms showed that multiple isoforms were indeed active. Our data indicate that the PKC inhibited adenylate cyclases IV and VI and the calcium‐stimulated isoform I predominate in bovine cumulus cells. Mol. Reprod. Dev. 1202–1210, 2006. © 2006 Wiley‐Liss, Inc.
Effects of cord motion on diffusion imaging of the spinal cord
Authors: Kharbanda Hardave S. , Alsop David C. , Anderson Adam W. , Filardo Giovanni , Hackney David B.
Published: June 2006

Measurement of diffusion and its dependence on direction has become an important tool for clinical and research studies of the brain. Diffusion imaging of the spinal cord may likewise prove useful as an indicator of tissue damage and axonal integrity; however, it is more challenging to perform diffusion imaging in the cord than in the brain. Here we report a study of the effects of motion on single‐shot fast spin echo (FSE) diffusion tensor imaging (DTI) of the spinal cord. Diffusion imaging was performed at four different times in the cardiac cycle both without and with velocity compensation of the diffusion gradients. Uncompensated diffusion images demonstrated substantial signal loss artifacts in the cord that were strongly dependent on the delay after the pulse‐oximeter trigger. Quantitative diffusion analysis was also strongly affected by this motion artifact. The use of flow‐compensated gradients helped to restore normal signal in the cord, especially at particular trigger delays. Theoretical arguments suggest that improved spatial resolution may help eliminate this signal loss. Even with higher spatial resolution, motion‐related signal attenuation may still occur in diffusion imaging of pathologies that alter the motion of the cord. However, this same cord motion may contain diagnostically valuable information when probed using appropriate diffusion imaging approaches. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
On extended formulations for the precedence constrained asymmetric traveling salesman problem
Authors: Gouveia L. , Pesneau P.
Published: June 2006

In this article we study the use of formulations with precedence relation variables for the Precedence Constrained Asymmetric Travelling Salesman (PCATS) problem. Contrary to previous articles, the emphasis of this article is on formulations involving exponential sized sets of inequalities and on the development of a cutting plane method together with polynomial routines for separating the new inequalities. Our computational results, taken from a set of benchmark instances, show that our methods improve significantly on most of the best previously known lower bound values. © 2006 Wiley Periodicals, Inc. NETWORKS, Vol. 48(2), 77–89 2006
Deformation mechanism of polystyrene toughened with sub‐micrometer monodisperse rubber particles
Authors: Gao Guanghui , Zhang Jingshu , Yang Haidong , Zhou Chao , Zhang Huixuan
Published: June 2006

Core–shell polybutadiene‐graft‐polystyrene (PB‐g‐PS) rubber particles with different ratios of polybutadiene to polystyrene were prepared by emulsion polymerization through grafting styrene onto polybutadiene latex. The weight ratio of polybutadiene to polystyrene ranged from 50/50 to 90/10. These core‐shell rubber particles were then blended with polystyrene to prepare PS/PB‐g‐PS blends with a constant rubber content of 20 wt%. PB‐g‐PS particles with a lower PB/PS ratio (≤70/30) form a homogeneous dispersion in the polystyrene matrix, and the Izod notched impact strength of these blends is higher than that of commercial high‐impact polystyrene (HIPS). It is generally accepted that polystyrene can only be toughened effectively by 1–3 µm rubber particles through a toughening mechanism of multiple crazings. However, the experimental results show that polystyrene can actually be toughened by monodisperse sub‐micrometer rubber particles. Scanning electron micrographs of the fracture surface and stress‐whitening zone of blends with a PB/PS ratio of 70/30 in PB‐g‐PS copolymer reveal a novel toughening mechanism of modified polystyrene, which may be shear yielding of the matrix, promoted by cavitation. Subsequently, a compression‐induced activation method was explored to compare the PS/PB‐g‐PS blends with commercial HIPS, and the result show that the toughening mechanisms of the two samples are different. Copyright © 2006 Society of Chemical Industry
Tokamak und Stellarator – zwei Wege zur Fusionsenergie: Fusionsforschung
Authors: Milch Isabella
Published: June 2006

Im Laufe der Fusionsforschung haben sich zwei Bautypen für ein zukünftiges Kraftwerk als besonders aussichtsreich erwiesen: Tokamak und Stellarator. Mit dem geplanten Tokamak‐Experimentalreaktor ITER steht die internationale Fusionsforschung vor der Demonstration eines Energie liefernden Plasmas. Parallel soll die in Greifswald entstehende Forschungsanlage Wendelstein 7‐X die Kraftwerkstauglichkeit des alternativen Bauprinzips der Stellaratoren zeigen.
Sandsturm kontra Wassersturm: Physik im Alltag
Authors: Müller Andreas
Published: June 2006

Sandstürme ereignen sich oft, “Wasserstürme” hingegen so gut wie nie. Eine Abschätzung zeigt, dass man beim Herauslösen eines Wassertropfens beispielsweise aus dem Meer eine sehr große Kraft benötigt und sehr viel Arbeit verrichten muss. Das scheint die Erklärung zu sein. Führt man eine entsprechende Energiebetrachtung durch, so könnte es durchaus Wasserstürme geben. Diese Überlegung ist zwar mathematisch richtig, aber unvollständig.
Hochtemperatur‐Supraleiter in der Technik: 20 Jahre Hochtemperatur‐Supraleitung
Authors: Malozemoff Alex , Mannhart Jochen , Scalapino Doug
Published: June 2006

Zwanzig Jahre nach ihrer Entdeckung halten Hochtemperatur‐Supraleiter Einzug in kommerzielle Anwendungen. Elektromotoren und Generatoren, etwa für Schiffe, supraleitende Strombegrenzer und Schwungradsysteme werden gegenwärtig entwickelt. Solche elektrischen Maschinen sind kompakter und leichter als konventionelle und besitzen ein großes Marktpotenzial. Die häufigsten kommerziellen Anwendungen sind gegenwärtig Mikrowellenfilter für Mobilfunk‐Basisstationen, Synchronmotoren zur dynamischen Regelung der Blindleistung in Stromnetzen sind auf dem Markt, erste Maschinen wurden schon kommerziell vertrieben.
Wenn Nudeln fingerhakeln
Authors: Vilgis Thomas
Published: June 2006

Gekochte Pasta klebt gern zusammen, weil sie ihren eigenen Klebstoff mitbringt. Dieser kann durch die Weißfärbung des Kochwassers gesichtet werden. Die Trübung und ebenfalls die Schaumbildung sind stets auf gelöste beziehungsweise an die Oberfläche getragene Proteine und Stärke zurückzuführen. Je länger Pasta gekocht wird, desto mehr treten derartige Polymerketten aus den Nudeln aus und gehen baden. Aber nicht nur, denn auch die Oberfläche der Nudeln gestaltet sich, hätten wir die Möglichkeit genauer hinzusehen, recht haarig.
Crystallization behavior and morphological development of isotactic polypropylene blended with nanostructured polyhedral oligomeric silsesquioxane molecules
Authors: Chen Jean‐Hong , Chiou Young‐Di
Published: June 2006

The thermal properties and morphological development of isothermally crystallized isotactic polypropylene (iPP) blended with nanostructured polyhedral oligomeric silsesquioxane (POSS) molecules at very small loading of POSS were studied with differential scanning calorimeter (DSC), thermal gravimetric analysis, dynamic mechanical analysis, polarized optical microscopy (POM), and wide‐angle X‐ray diffraction (WAXD). The result of DSC indicated that the crystallization rate of iPP increases with the increase in POSS contents during crystallization; moreover, the melting temperature of iPP/POSS nanocomposites slightly decreases, while the heat of fusion increases with the addition of POSS molecules at melting and remelting traces. The storage modulus and thermal stability, respectively, remarkably decrease, while the glass transition temperature of isothermally crystallized iPP/POSS nanocomposites increases slightly with the increase in POSS contents. The morphologies results of WAXD and POM show that the POSS molecules form about 35 nm sized nanocrystals and aggregate to form thread‐like and network structure morphologies, respectively, in the molten state even when the POSS content is very small. These results, therefore, suggest that the interaction force between the POSS molecules should be larger than the force between POSS molecules and iPP matrix; however, those interactions depend on the chain length of functionalized substituents on the POSS cage. Therefore, the POSS molecules aggregate forming nanocrystals and act as an effective nucleating agent for iPP and influence the thermal properties of iPP/POSS nanocomposites due to the shorter chain length of functionalized substituents, methyl, on the POSS cage. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2122–2134, 2006
Investigations of secondary explosions induced by venting
Authors: Chen Zhihua , Fan Baochun , Jiang Xiaohai , Ye Jingfang
Published: June 2006

A series of vented explosion tests were performed in a small‐scale cylindrical vessel using a short discharge duct. Overpressure–time profiles were recorded with five transducers both inside and outside of the vessel. Visualization of the flow field is provided by a high‐speed shadowgraph imaging system using sequential shadowgraphs. As is well known, two or more pressure peaks can occur during explosion venting, one from the vent rupture and the other from a secondary explosion induced by combustion of the vented combustible gases. Three typical distinct processes of vented explosions were found. Variations in intensity of the secondary explosion were measured as a function of vent burst pressure, ignition location, blockage ratio at the vent, and equivalence ratio of the fuel. © 2006 American Institute of Chemical Engineers Process Saf Prog, 2006
Effect of packaging film on the quality of ‘Chaoyang’ honey peach fruit in modified atmosphere packages
Authors: An Jianshen , Zhang Min , Zhan Zhonggang
Published: June 2006

The quality of honey peach fruit stored at 2°C in modified atmosphere packages was studied. Three different thickness low‐density polyethylene (LDPE) films were used as packaging films. Honey peach fruits of ‘chaoyang’ were packaged in LDPE bags 15, 25 and 40µm thick and control (air). The respiration rate, O2 and CO2 concentrations in the packages, flesh colour, total soluble solid (TSS), titratable acidity (TA), flesh firmness (FF) and membrane integrity of the fruits were monitored. Compared to the control, MAP treatments inhibited the climacteric peak, avoided the increase of flesh colour, decreased the development of softness and retarded the reduction of TTS, TA and membrane integrity. Significant differences in the quality of the fruits were found between the three packages and the control (p ≤ 0.05). After 20 days at 2°C within the LDPE25 bags, a steady‐state atmosphere of 5% CO2 + 4% O2 was reached. Honey peaches stored in these bags showed the best quality at the end of the storage. Copyright copy; 2006 John Wiley & Sons, Ltd.
The Effect of Variable Selection on the Non‐linear Modelling of Oestrogen Receptor Binding
Authors: Ghafourian Taravat , Cronin Mark T. D.
Published: June 2006

Oestrogen Receptor Binding Affinity (RBA) is often used as a measure of the oestrogenicity of endocrine disrupting chemicals. Quantitative Structure–Activity Relationship (QSAR) modelling of the binding affinities has been performed by three‐dimensional approaches such as Comparative Molecular Field Analysis (CoMFA). Such techniques are restricted, however, for chemically diverse sets of chemicals as the alignment of molecules is complex. The aim of the present study was to use non‐linear methods to model the RBA to the oestrogen receptor of a large diverse set of chemicals. To this end, various variable selection methods were applied to a large group of descriptors. The methods included stepwise regression, partial least squares and recursive partitioning (Formal Inference Based Recursive Modelling, FIRM). The selected descriptors were used in Counter‐Propagation Neural Networks (CPNNs) and Support Vector Machines (SVMs) and the models were compared in terms of the predictivity of the activities of an external validation set. The results showed that although there was a certain degree of similarities between the structural descriptors selected by different methods, the predictive power of the CPNN and SVM models varied. Although the variables selected by stepwise regression led to poor CPNN models they resulted in the best SVM model in terms of predictivity. The parameters selected by some of the FIRM methods were superior in CPNN.
Methanolothermal Synthesis of [Mn(en)3][Mn2(SbSe4)2(en)4(H2O)] [Mn(en)3][{Mn(en)2(H2O)}2(μ‐SbSe4)][Mn(μ‐SbSe4)(en)2]Cl2 representing the First Example of a Transition Metal‐containing Ternary Catena‐Selenidoantimonate(V)
Authors: van Almsick Tobias , Sheldrick William S.
Published: June 2006

[Mn(en)3][Mn2(SbSe4)2(en)4(H2O)] (1) and [Mn(en)3][{Mn(en)2(H2O)}2 (μ‐SbSe4)] [Mn(μ‐SbSe4)(en)2]Cl2 (2) may be prepared by methanolothermal reaction of Mn(OOCCH3)2 · 4H2O with elemental Sb and Se in the presence of CsCl in a 1:1 CH3OH/en mixture at 190°C. The [Mn2(SbSe4)2(en)4(H2O)]2− anions of 1 contain two [Mn(en)2]2+ fragments bridged by a single Se atom of an SbSe44− anion in a 1κSe: 2κSe manner. The remaining sites in the MnII octahedral coordination spheres are occupied by a κSe coordinating [SbSe4]3− anion and a water ligand, respectively. In contrast, black coloured 2 contains both polymeric $^{1}_{\infty}$[{Mn(μ‐SbSe4)(en)2}‐] anions and disordered dinuclear [{Mn(en)2(H2O)}2(μ‐SbSe4)]+ cations.
Layered Crystal Structure and Vibrational Spectra of Sodium Trichloromethanesulfonate – An Eperimental and Theoretical Study
Authors: Tuttolomondo M. E. , Piro O. E. , Varetti E. L. , Altabef A. Ben
Published: June 2006

The NaCCl3SO3.H2O salt was studied by X‐ray diffraction methods, which show that it crystallizes in the monoclinic P21/c space group, with a = 12.558(5), b = 5.814(3), c = 10.679(5) Å, β = 103.76(3)°, and Z = 4. The solid is arranged into neutral slabs, parallel to each other and to the crystal bc plane, being each slab held mainly by ionic forces. An infrared and Raman study of that compound was also performed and an assignment of the observed spectral features was made, correcting results previously reported by other authors. The vibrational study was supported by quantum chemistry calculations at the DFT level, from which the theoretical frequencies of vibration and a force field for the anion were obtained. That force field was subsequently adjusted to reproduce the set of experimental frequencies.
Fußball verstehen - Beiträge der Sozialpsychologie
Authors: Plessner Henning , Freytag Peter , Strauß Bernd
Published: June 2006

Zusammenfassung: Mit der Fußballweltmeisterschaft 2006 in Deutschland werden erneut einige Problemfelder des Fußballs, die im Kern psychologischer Natur sind, eine erhöhte öffentliche Aufmerksamkeit erzeugen. Dazu zählen unter anderem die Frage nach dem Heimvorteil des ausrichtenden Verbandes, die Fehleranfälligkeit von Schiedsrichterentscheidungen und die Gefahr von Zuschauerausschreitungen. Anhand eines Überblicks über empirische Arbeiten zu diesen ausgewählten Themenbereichen wird deutlich gemacht, dass es insbesondere Beiträge mit sozialpsychologischem Hintergrund sind, die es ermöglichen, zu entsprechenden Fragestellungen fundiert Stellung zu beziehen und Ansätze für Problemlösungen zu erarbeiten. Darüber hinaus wird aufgezeigt, dass der Fußballsport unter Umständen ein besonders günstiges Anwendungsfeld zur Überprüfung sozialpsychologischer Theorien bietet.
Spatial distributions of volatile sulfur compounds in surface seawater and overlying atmosphere in the northwestern Pacific Ocean, eastern Indian Ocean, and Southern Ocean
Authors: Inomata Yayoi , Hayashi Masahiko , Osada Kazuo , Iwasaka Yasunobu
Published: June 2006

Distributions of volatile sulfur compounds (carbonyl sulfide (COS), carbon disulfide (CS2), hydrogen sulfide (H2S), dimethyl sulfide (DMS)) in surface seawater and overlying atmosphere were measured in the northwestern Pacific, eastern Indian, and Southern Oceans (40°N–66°S, 40°E–140°E) in November–December 1996 during the 38th Japanese Antarctic Research Expedition cruise. Seawater measurements revealed that DMS was the dominant sulfur compound, with concentrations of 0.5–15.8 nM. High values were found in the Southern Ocean's marginal ice zone (84°E–63°E, 59°S–63°S), suggesting that the area during the bloom acts as an important source of atmospheric DMS. Atmospheric concentrations were 456–471 pptv for OCS, n.d. (not detected level) −13 pptv for CS2, n.d. −17 pptv for H2S, and n.d. −755 pptv for DMS. Concentrations of OCS were nearly constant. Concentrations of CS2 and H2S were high in terrigenic air masses and low in those of oceanic origin. Comparison of atmospheric DMS data and a steady state box model using sea‐to‐air fluxes of DMS and assumed OH radical concentrations revealed that atmospheric DMS concentrations in the equatorial region and most of the Southern Ocean were balanced with local oceanic emission residues and photochemical oxidation. Simultaneous measurements in the atmosphere showed DMS was the dominant sulfur gas that was oxidized rapidly to sulfate aerosols in the marine atmosphere.
Interannual variability of winter oceanic CO2 and air‐sea CO2 flux in the western North Pacific for 2 decades
Authors: Midorikawa Takashi , Ishii Masao , Nemoto Kazuhiro , Kamiya Hitomi , Nakadate Akira , Masuda Shinji , Matsueda Hidekazu , Nakano Toshiya , Inoue Hisayuki Y.
Published: June 2006

The 2‐decade records of the partial pressure of CO2 in surface waters (pCO2sea) and the resulting air‐sea CO2 flux in the extensive subtropical to equatorial area along 137°E in the western North Pacific in winter exhibited significant interannual variations that differed in different regions. The pCO2sea varied largely in the equatorial region of 3°N to 6°N, depending on the oceanographic conditions related to the El Niño–Southern Oscillation (ENSO) events. The magnitude of the variations differed year by year, corresponding to the different degrees of compensation between the sea surface temperature (SST) and dissolved inorganic carbon (DIC) effects on pCO2sea during the events. Small pCO2sea variations in the subtropical gyre north of 23°N were due to highly counteracting effects between anticorrelated SST and DIC anomalies through the entrainment process. In contrast, a low negative correlation existed between SST and DIC, associated with the lateral advection in the region restricted around 15°N to 18°N in the North Equatorial Current, resulting in a large amplitude of variations of pCO2sea and hence CO2 influx. The interannual variations of CO2 flux depended predominantly on the difference in pCO2 between air and sea south of 18°N, but on wind speed in the northern region. It is important to monitor how the contributions of different properties to the CO2 flux could change in the western North Pacific, responding to possible shifts of the ENSO conditions and the future progress of global warming.
Optical scattering patterns from single urban aerosol particles at Adelphi, Maryland, USA: A classification relating to particle morphologies
Authors: Aptowicz K. B. , Pinnick R. G. , Hill S. C. , Pan Y. L. , Chang R. K.
Published: June 2006

Angularly resolved elastic light scattering patterns from individual atmospheric aerosol particles (diameter 0.5–12 micrometers) sampled during fall (October 2004) at an urban site in the Baltimore‐Washington metroplex are reported. These two‐dimensional angular optical scattering (TAOS) patterns were collected for polar scattering angles θ varying from approximately 75° to 135° and azimuthal angles ϕ varying from 0° to 360°. Approximately 6000 scattering patterns were sampled over a span of 18 hours from an inlet located above our laboratory roof at Adelphi, Maryland. Our instrument recorded light scattering patterns of higher resolution and accuracy than have previously been achievable. The patterns suggest that background aerosol particles have diverse morphologies ranging from single spheres to complex structures. The frequency of occurrence of particle morphologies inferred from the TAOS patterns is strongly dependent on size. For nominally 1‐μm particles, 65% appear spherical (or perturbed sphere) and only about 9% have complex structure (as suggested by their complex scattering features); whereas for nominally 5‐μm particles, only 5% appear spherical (or perturbed sphere) and 71% appear to have complex structure. The patterns are quantitatively characterized using a degree of symmetry (Dsym) factor, calculated by examining both mirror and rotational symmetries in each pattern. In our measurements, atmospheric particles have two distinct populations: mostly micron‐sized particles with Dsym values close to that of spheres and a population of mostly supermicron particles having a low but broad range of Dsym values. These observations are consistent with the commonly accepted notion that most micron‐sized particles (in the accumulation mode) appear to be nearly spherical and are probably formed in the atmosphere through gas‐particle reactions; whereas most supermicron particles appear to be nonspherical and are likely directly injected into the atmosphere. Our observations suggest that Lorenz‐Mie theory may be adequate for most micron‐sized particles but not for supermicron particles.
Online gas and aerosol measurement of water soluble carboxylic acids in Zurich
Authors: Fisseha Rebeka , Dommen Josef , Gaeggeler Kathrin , Weingartner Ernest , Samburova Vera , Kalberer Markus , Baltensperger Urs
Published: June 2006

We discuss the diurnal and seasonal variability of low molecular weight organic acids in Zurich city on the basis of online quasi‐continuous measurement in the gas and aerosol phase using a wet effluent diffusion denuder/aerosol collector (WEDD/AC) coupled to ion chromatography. The measurements were performed during August–September 2002 and March 2003. Acetic acid exhibited the highest concentration in the gas phase during all the measurement periods, followed by formic acid. Oxalic acid was predominantly found in the aerosol phase and often below the detection limit in the gas phase. In addition, filter samples were analyzed using ion chromatography–mass spectrometry (IC‐MS) to provide more information on organic acids in the aerosol phase. From the offline IC‐MS measurements, 20 monocarboxylic, dicarboxylic, and tricarboxylic acids were determined. In addition, more than 20 different masses were detected with the MS; however, identification of the organic acids was not possible. The sum of the carboxylic acids contributed on average 2% to the water soluble organic carbon (WSOC). The fraction of dicarboxylic acids to the WSOC was higher in summer compared to winter suggesting that dicarboxylic acids are mainly a result of photochemical reactions in summer whereas in winter they mainly result from primary sources.
How does underlying geology affect coastline change? An initial modeling investigation
Authors: Valvo Lisa M. , Murray A. Brad , Ashton Andrew
Published: June 2006

Conceptual geologic framework models predict that areas of the coast underlain by a weak or very fine grained lithology retreat landward faster than adjacent, more resistant or coarser‐grained segments. These apparently commonsense predictions seem inconsistent with observations that sandy coastlines underlain by heterogeneous lithology remain fairly smooth. We have developed a numerical model to explore the interaction between shoreface lithology effects and alongshore transport processes on scales greater than years and kilometers. Shoreline indentations, or sections of the coast that are slightly landward of adjacent sections, tend to form in the model where the shoreface weathers more rapidly or is composed of finer‐grained material. However, alongshore transport tends to fill in these indentations, slowing the weathering rates there while increasing them in adjacent areas where mobile sediment is preferentially removed. Over the long term this leads to an alongshore uniform retreat rate. Subtle shoreline undulations reflecting the heterogeneous geologic framework exist in the model, but their amplitude reaches a steady state rather than increasing with time. Compositional heterogeneities determine the morphology of the coast while weathering rate heterogeneities control the thickness of sediment on the shoreface. Thus indentations can form in sections composed of harder (less erodible) rocks if they are finer grained.
Specification of >2 MeV geosynchronous electrons based on solar wind measurements
Authors: Burin des Roziers E. , Li X.
Published: June 2006

Relativistic electron flux measurements from geosynchronous satellites show a local time dependence. This local time dependence is due to the radial profile of the electron fluxes and the dayside/nightside asymmetry of the Earth's magnetosphere and is also affected by geomagnetic activity, which is in turn affected by the solar wind. Statistical asynchronous regression (SAR), a statistical method recently adapted for magnetospheric studies, was used to determine the relationship between electron fluxes measured at different local times, as a function of the Kp index (O'Brien et al., 2001). In this study, we use measurements directly from the solar wind, instead of the Kp index, and the SAR method as the basis for determining the local time dependence of geosynchronous energetic electron fluxes. We use solar wind parameters as input in our model to map GOES 10 > 2 MeV electron measurements to other local times and compare them with electron measurements from five widely spaced LANL geosynchronous satellites when they pass through these local times. We cross calibrate the electron measurements from the five LANL satellites and find that the averaged electron flux from individual satellites can differ by up to 50% even though the particle detectors were identically designed. In this study, we normalize measurements from each LANL spacecraft to the average value of all five LANL spacecraft. We also cross calibrate the electron measurements from the LANL satellites and from GOES 10 and find that the energy spectrum is best described by a power law index which is a function of the current average LANL 1.1–1.5 MeV electron flux level. We explore the effects of solar wind velocity, dynamic pressure, and density on the local time dependence of geosynchronous electron fluxes. We find that for the given 4.3 year data set, using only solar wind velocity gives rise to the best results. We check the efficacy of the model by mapping GOES 10 > 2 MeV electron measurements at other local times to local noon and comparing with electron measurements from LANL satellites when they pass through local noon: We achieve an out‐of‐sample prediction efficiency (PE) of 0.83 and a linear correlation coefficient (LC) of 0.93 for January 2000, whereas we achieve a PE of 0.81 and LC of 0.92 for the year 2000. The PE and LC are different when mapping GOES 10 > 2 MeV electron measurements at one local time to other local times, with the highest PE around prenoon and afternoon and the lowest near midnight.
Geometrical factors and interfacial processes affecting complex dielectric permittivity of partially saturated porous media
Authors: Chen Yongping , Or Dani
Published: June 2006

Methods for remote and ground‐based sensing of soil water content often rely on determination of bulk dielectric permittivity which may be affected by factors other than water content, such as interfacial polarization (Maxwell‐Wagner effect), phase configuration, and electrical conductivity. The complex interactions among these factors were modeled by the Maxwell‐Wagner‐Bruggeman‐Hanai formalism on the basis of self‐consistent differential effective medium approximation. The modeling framework considers porous media composed of coated inclusions and enables systematic evaluation of various factors on determination of water content at different measurement frequencies associated with different sensors. Simulation results illustrate the importance of accounting for phase configuration; using a simple saturation‐dependent weight function and only two typical phase configurations provided good agreement with a wide range of dielectric measurements spanning different porous media, saturations, and measurement frequencies. The model provides the necessary framework for incorporation of the Maxwell‐Wagner effect on standard measurements obtained by time domain reflectometry and through frequency response enables evaluation and a wide array of other sensors. Work is under way to incorporate effects of ambient conditions (temperature) and of bound water on bulk dielectric measurements.
Observations of amplitude saturation in ELF/VLF wave generation by modulated HF heating of the auroral electrojet
Authors: Moore R. C. , Inan U. S. , Bell T. F.
Published: June 2006

We present detailed observations of the onset of amplitude saturation in ELF/VLF waves generated via modulated HF heating of naturally‐forming, large‐scale current systems, such as the auroral electrojet. Broadband ELF/VLF measurements at a ground‐based receiver located near the High‐Frequency Active Auroral Research Program (HAARP) HF transmitter in Gakona, Alaska, exhibit variations in signal amplitude which are qualitatively consistent with a hard‐limiting approximation of the saturation process. A method to approximate the saturation curve as a function of HF power from experimental data is presented, and the results indicate that a ∼5–10% reduction in generated ELF signal amplitude is typical at the maximum radiated HF power level (771 kW) for modulation frequencies between 1225 Hz and 3365 Hz. For HF transmissions using sinusoidal amplitude modulation, the saturation dominantly affects the second harmonic of the generated ELF/VLF signal, with amplitudes on average 16% lower than expected at the maximum HF power level.
Horizontal dispersion in the sea caused by recurring changes of the depth of the wind drift
Authors: Nerheim Signild , Stigebrandt Anders
Published: June 2006

This paper explores a new horizontal dispersion mechanism due to recurrent changes of the depth of the wind drift. In the shallow mode, the wind drift moves the upper part of the surface layer relative to the lower part, giving an increased horizontal area being covered by a tracer present in the layer. When returning to the deep mode, the accompanying vertical mixing increases the volume of the cloud. The rate of increase of the tracer cloud area is proportional to the wind drift velocity in the shallow mode and the area itself, and therefore proportional to the elapsed time squared t2. The t2‐law is demonstrated by a numerical experiment and supported by published experimental results. The quadratic dependence is explained by the larger and larger exposure to wind driven advection and not by larger and larger scales of motions taking part in the process known from eddy dispersion.