bluuebunny/crossref_metadata_2025 huggingface dataset:
Global legal pluralism as fact and norm
Authors: ISIKSEL TURKULER
Published: July 2013

This article interrogates the intellectual foundations of global legal pluralism as a descriptive and normative position, and assesses its core claims with reference to the changing status of individuals in the postnational realm. In order to uncover the normative core of the pluralist position, the article turns to the rich tradition of value pluralism in political philosophy, particularly as articulated by Isaiah Berlin. It argues that as a normative position, pluralism – whether applied to the abstract sphere of values or the concrete realm of legal regimes – is normatively underdetermined, offering too little guidance as to how the conflicts endemic to a pluralistic world ought to be resolved. Unless it is supplemented by other, more substantive principles of political legitimacy such as democracy, freedom, equality, or justice, the principle of pluralism applied to the global legal realm is poised to reproduce, even exacerbate, existing inequalities of power and resources among those whom it affects.
1914–2014: never again
Authors: Jacobs Howy
Published: July 2013

The coming year marks the centenary of the events that lead to the global catastrophe of July 1914. Howy appeals for a worldwide movement to prevent any possibility of such a disaster occurring in today's equally unstable world.
Extraordinary expansion of a Sorangium cellulosum genome from an alkaline milieu
Authors: Han Kui , Li Zhi-feng , Peng Ran , Zhu Li-ping , Zhou Tao , Wang Lu-guang , Li Shu-guang , Zhang Xiao-bo , Hu Wei , Wu Zhi-hong , Qin Nan , Li Yue-zhong
Published: July 2013

Complex environmental conditions can significantly affect bacterial genome size by unknown mechanisms. The So0157-2 strain ofSorangium cellulosumis an alkaline-adaptive epothilone producer that grows across a wide pH range. Here, we show that the genome of this strain is 14,782,125 base pairs, 1.75-megabases larger than the largest bacterial genome fromS. cellulosumreported previously. The total 11,599 coding sequences (CDSs) include massive duplications and horizontally transferred genes, regulated by lots of protein kinases, sigma factors and related transcriptional regulation co-factors, providing the So0157-2 strain abundant resources and flexibility for ecological adaptation. The comparative transcriptomics approach, which detected 90.7% of the total CDSs, not only demonstrates complex expression patterns under varying environmental conditions but also suggests an alkaline-improved pathway of the insertion and duplication, which has been genetically testified, in this strain. These results provide insights into and a paradigm for how environmental conditions can affect bacterial genome expansion.
A dynamically reconfigurable Fano metamaterial through graphene tuning for switching and sensing applications
Authors: Amin M. , Farhat M. , Baǧcı H.
Published: July 2013

We report on a novel electrically tunable hybrid graphene-gold Fano resonator. The proposed metamaterial consists of a square graphene patch and a square gold frame. The destructive interference between the narrow- and broadband dipolar surface plasmons, which are induced respectively on the surfaces of the graphene patch and the gold frame, leads to the plasmonic equivalent of electromagnetically induced transparency (EIT). The response of the metamaterial is polarization independent due to the symmetry of the structure and its spectral features are shown to be highly controllable by changing a gate voltage applied to the graphene patch. Additionally, effective group index of the device is retrieved and is found to be very high within the EIT window suggesting its potential use in slow light applications. Potential outcomes such as high sensing ability and switching at terahertz frequencies are demonstrated through numerical simulations with realistic parameters.
Catalysis at the Organic Ligands
Authors: Mondloch Joseph E. , Farha Omar K. , Hupp Joseph T.
Published: July 2013

Crystalline metal organic frameworks containing catalytically active organic linkers or ancillary ligands (i.e., catalysts at the organic ligands) are an intriguing sub‐set of heterogeneous catalysts. These catalysts are atomically defined and offer a platform to readily designed single‐site catalysts. The literature encompasses approximately fifty experimental examples from which we highlight a handful of what we perceive to be,key conceptual papers. It is clear that many of the attractive visions for MOF catalysts—including, “multi‐catalyst architectures”, “metal coordination environments that can be achieved in no other ways” and “reactivity‐defining microenvironments”—are starting to be realized.
Photocatalysis by MOFs
Authors: García Hermenegildo , Ferrer Belén
Published: July 2013

In this chapter it has been exemplified that MOFs can exhibit photoactivity derived from the interaction of the organic linker with the inorganic clusters. Comparison with analogous systems in solution shows that the crystal lattice of MOF, in which the linker and the organic cluster have intimate contact, originates a photochemical response that is not found for the homogeneous solution. Furthermore, MOFs can act as passive matrices to accommodate, in the internal voids, photoactive chromophores that can exhibit a distinctive response due to the properties of the surrounding media. All the discussed examples illustrate the possibility of obtaining interesting photoresponses that can open up applications beyond absorption and catalysis. Among these applications we have commented the use of MOFs as photocatalysts for environmental remediation and for the generation of solid fuels, particularly hydrogen, as well as applications in optoelectronics including solar cells and phosphors. All these applications derive from the consideration of MOFs as semiconductors.
Catalysis by Covalent Organic Frameworks (COFs)
Authors: Rose Marcus , Palkovits* Regina
Published: July 2013

Porous covalent organic frameworks (COFs) are an emerging class of versatile materials. They provide novel possibilities for application as solid catalysts in heterogeneous catalysis due to their defined tailorable structures and surface chemistry, in combination with a high porosity. Thus, access to highly disperse catalytic centers is enabled and mass transport effects can be easily tuned. Catalytic active centers in COFs result from one of three different ways: (i) utilization of the porous frameworks as supports for metal nanoparticles or clusters with additional stabilization via coordination effects. (ii) Immobilization of molecular metal species within coordinating heteroatom moieties at well‐defined organic linkers, which is comparable to a heterogenization of homogeneous catalyst species. (iii) Intrinsic catalytic properties of metal‐free organic frameworks due to heteroatoms or defined functional groups especially in organocatalysis. In recent years many novel COF materials have been tested in various catalytic reactions proving their suitability as solid catalysts.
Towards Future MOF Catalytic Applications
Authors: Llabrés i Xamena Francesc X. , Gascon Jorge
Published: July 2013

In this last chapter of the book, we highlight additional aspects, also very relevant for the future application of MOFs in catalytic processes at the industrial scale, but that have not been explicitly treated in the other chapters. On one hand, we discuss the potential of (multi-functional) MOF catalysts for one-pot tandem reactions or multicomponent coupling reactions as a means of process intensification to improve the economy of the system. On the other hand, we highlight the different approaches followed for the shaping of MOF catalysts, one of the critical steps before industrial implementation.
Advanced Thermal Treatment of Wastes for Fuels, Chemicals and Materials Recovery
Authors: Wu Chunfei , Williams Paul T.
Published: July 2013

The advanced thermal technologies of pyrolysis and gasification provide important economic and environmental options to convert waste materials into useful and high‐value materials, fuels and chemicals. In this chapter, pyrolysis is described in terms of the production of oils, char and gas, with examples of various reaction systems. Gasification is also reviewed in terms of example process systems, influences of gasification temperature and the presence of catalysts. Commercial examples of both technologies are also described.
Resource Recovery from Mine Waste
Authors: Shaw Richard A , Petavratzi Evangelia , Bloodworth Andrew J
Published: July 2013

Rock and mineral waste from the extraction of metals and minerals from the Earth is produced on a vast scale. The characteristics of mine waste are described, along with how this material relates to the nature of original mineral deposits. The influence of the method of mining and processing on the type and volume of waste is described, along with various potential environmental impacts of the waste material. The economic and environmental factors that influence the recovery of resources from mine waste are discussed and a brief overview is given of the various metallurgical technologies available to separate resources from waste. A series of case studies are given which focus on the recovery of relatively high value metals from various waste streams which result from the extraction and processing of alumina (scandium, yttrium, vanadium and rare earth elements), nickel (cobalt, nickel), gold (gold, silver), copper (cobalt, copper) and zinc (indium). The current low level of resource recovery from mine waste is noted and some of the reasons behind this low level of utilisation are explored. Increased future demand for metals is likely to drive up prices. This will provide a strong incentive for mine operators to re‐examine their waste streams as potential sources of alternative products. The environmental and ethical requirements to improve mine output whilst minimising the environmental footprint might also prove a powerful driver to better utilisation of mine waste as a resource.
Recent Developments in the Area of Waste as a Resource, with Particular Reference to the Circular Economy as a Guiding Principle
Authors: Pinjing He , Fan Lü , Hua Zhang , Liming Shao
Published: July 2013

Nowadays, an increasing number of countries realise the need for a circular economy; similar concepts, such as “sustainable society” and “recyclable society”, have been proposed, together with a series of practices such as those embodied in the terms “Roadmap to a Resource Efficient Europe”, “Biomass Refinery Industrial Complex” (Japan) and “EcoAgrobusiness Park” (New Jersey, USA). Resource‐ and energy‐recovery from waste plays an essential role in the context of a circular economy. In this chapter, the relationship of waste to the circular economy is discussed on the basis of recent successful practices. The technical and economic viability of waste as a resource is described.
Composting and Compost
Authors: Stentiford Ed
Published: July 2013

Composting is a complex biological process which, when engineered and controlled, can deliver a high quality product which returns nutrients to the soil and improves its structure. This chapter looks at the fundamental processes which drive the composting process and then the key features which the process needs to deliver a quality product.

The biological degradation process can be represented by a series of exponential decay terms, each one representing a different component of the feedstock. Researchers have found that, in practice, the decay of most material mixtures can be represented by using two components, one of which has a ‘fast’ rate, e.g. starch and sugars, and the other having a ‘slow’ rate, e.g. cellulose. The decay of typical wastes used in composting, such as domestic refuse and mixtures of sewage sludge and woodchips, can be represented by using two rate constants. The degradation releases heat, the use of which is the key to effective composting, producing pile core temperatures in the 55 to 70°C range. The elevated temperature serves two purposes, firstly to sanitise the material (kill off most of the pathogens) and secondly to maximise the rate of degradation. Each 10°C increase in temperature, up to around 55°C, effectively doubles the reaction rate, making the process far more rapid than if it occurred at ambient temperatures. The key requirements to produce these conditions in a practical situation, i.e. pile structure (to facilitate aeration), available nutrients (primarily the C : N ratio) and the appropriate moisture content, are considered.
Structural basis for phosphorylation-triggered autophagic clearance of Salmonella
Authors: Rogov Vladimir V. , Suzuki Hironori , Fiskin Evgenij , Wild Philipp , Kniss Andreas , Rozenknop Alexis , Kato Ryuichi , Kawasaki Masato , McEwan David G. , Löhr Frank , Güntert Peter , Dikic Ivan , Wakatsuki Soichi , Dötsch Volker
Published: July 2013

Selective autophagy is mediated by the interaction of autophagy modifiers and autophagy receptors that also bind to ubiquitinated cargo. Optineurin is an autophagy receptor that plays a role in the clearance of cytosolic Salmonella. The interaction between receptors and modifiers is often relatively weak, with typical values for the dissociation constant in the low micromolar range. The interaction of optineurin with autophagy modifiers is even weaker, but can be significantly enhanced through phosphorylation by the TBK1 {TANK [TRAF (tumour-necrosis-factor-receptor-associated factor)-associated nuclear factor κB activator]-binding kinase 1}. In the present study we describe the NMR and crystal structures of the autophagy modifier LC3B (microtubule-associated protein light chain 3 beta) in complex with the LC3 interaction region of optineurin either phosphorylated or bearing phospho-mimicking mutations. The structures show that the negative charge induced by phosphorylation is recognized by the side chains of Arg11 and Lys51 in LC3B. Further mutational analysis suggests that the replacement of the canonical tryptophan residue side chain of autophagy receptors with the smaller phenylalanine side chain in optineurin significantly weakens its interaction with the autophagy modifier LC3B. Through phosphorylation of serine residues directly N-terminally located to the phenylalanine residue, the affinity is increased to the level normally seen for receptor–modifier interactions. Phosphorylation, therefore, acts as a switch for optineurin-based selective autophagy.
Tamoxifen inhibits macrophage FABP4 expression through the combined effects of the GR and PPARγ pathways
Authors: Jiang Meixiu , Zhang Ling , Ma Xingzhe , Hu Wenquan , Chen Yuanli , Yu Miao , Wang Qixue , Li Xiaoju , Yin Zhinan , Zhu Yan , Gao Xiumei , Hajjar David P. , Duan Yajun , Han Jihong
Published: July 2013

Macrophage adipocyte fatty acid-binding protein (FABP4) plays an important role in foam cell formation and development of atherosclerosis. Tamoxifen inhibits this disease process. In the present study, we determined whether the anti-atherogenic property of tamoxifen was related to its inhibition of macrophage FABP4 expression. We initially observed that tamoxifen inhibited macrophage/foam cell formation, but the inhibition was attenuated when FABP4 expression was selectively inhibited by siRNA. We then observed that tamoxifen and 4-hydroxytamoxifen inhibited FABP4 protein expression in primary macrophages isolated from both the male and female wild-type mice, suggesting that the inhibition is sex-independent. Tamoxifen and 4-hydroxytamoxifen inhibited macrophage FABP4 protein expression induced either by activation of GR (glucocorticoid receptor) or PPARγ (peroxisome-proliferator-activated receptor γ). Associated with the decreased protein expression, Fabp4 mRNA expression and promoter activity were also inhibited by tamoxifen and 4-hydroxytamoxifen, indicating transcriptional regulation. Analysis of promoter activity and EMSA/ChIP assays indicated that tamoxifen and 4-hydroxytamoxifen activated the nGRE (negative glucocorticoid regulatory element), but inhibited the PPRE (PPARγ regulatory element) in the Fabp4 gene. In vivo, administration of tamoxifen to ApoE (apolipoprotein E)-deficient (apoE−/−) mice on a high-fat diet decreased FABP4 expression in macrophages and adipose tissues as well as circulating FABP4 levels. Tamoxifen also inhibited FABP4 protein expression by human blood monocyte-derived macrophages. Taken together, the results of the present study show that tamoxifen inhibited FABP4 expression through the combined effects of GR and PPARγ signalling pathways. Our findings suggest that the inhibition of macrophage FABP4 expression can be attributed to the anti-atherogenic properties of tamoxifen.
New active islanding detection scheme for constant power and constant current controlled inverter‐based distributed generation
Authors: Samui Ankita , Samantaray Subhransu Ranjan
Published: July 2013

This study presents an active islanding detection scheme based on voltage positive feedback control strategy in synchronous d–q frame with a variable voltage gain. The proposed method employs the injection of a variable voltage gain at the DG end in order to monitor the responses of the proposed islanding detection technique. In this study, a complex frequency‐dependent ZIP‐exponential load model is included to assess the impact of load's active power frequency dependence on the performance of the proposed islanding detection scheme. The upper and lower limits of the voltage gain are designed for constant power and constant current controlled inverter with frequency‐dependent ZIP‐exponential load. The complete scheme is developed and tested in MATLAB/simulink environment and the results obtained after extensive testing indicate that the proposed scheme can be reliably detect islanding events in distributed generation.
Utilising energy storage systems to mitigate power system vulnerability
Authors: Teng Jen‐Hao , Chen Chia‐Yen , Martinez Ivan Curtis
Published: July 2013

Vulnerability mitigation is one of the most important issues for power system planning and operation. Recent research reveals that energy storage systems (ESSs) have a great potential to be used to mitigate power system vulnerability. However, their benefits greatly depend on the locations and capacities of ESSs installed. Therefore this study aims to find the optimal locations and capacities of ESSs for power system vulnerability mitigation. A vulnerability assessment is proposed in this study to calculate the impact factors for power systems based on generator and line outages. A bus impact severity (BIS) analysis is then designed and used to find the vulnerable buses in the power system. Formulations of optimal locations and capacities for ESS placement are derived and solved by a genetic algorithm‐based method. Since better locations for ESS placement can be found, the search space for ESS placement can be reduced effectively. Accordingly, the computational time for finding the optimal solution can be saved and the possibility to obtain a global optimum solution can be improved. Test results show that the proposed method can be used to find the optimal locations and capacities for ESS placement and mitigate system vulnerability effectively.
Co‐designed substrate‐integrated waveguide filters with patch antennas
Authors: Yusuf Yazid , Cheng Haitao , Gong Xun
Published: July 2013

A new approach to integrate high‐quality (Q)‐factor three‐dimensional vertical cavity filters with patch antennas into a single unit is presented. This integrated filter/antenna system exhibits small footprint, high efficiency and enhanced bandwidth. The patch antenna is designed to provide an additional transmission pole for the filtering function and works as a highly efficient radiator. In addition, this integrated patch antenna with a filter can achieve a bandwidth larger than that of a standalone patch antenna with the same geometry. A prototype three‐pole Chebyshev filter/antenna is demonstrated at X band. The centre frequency and fractional bandwidth of the filter/antenna system are 10.27 GHz and 8.7%, respectively. Owing to the high Q factor ( ∼650) of the cavity resonator and near loss‐less transition between the antenna and filter, the overall efficiency of the filter/antenna system is simulated to be as high as 91.8%. The reduced footprint, enhanced bandwidth and low‐loss performance of these integrated filter/antenna systems make them particularly useful for phased array applications. Prototypes of the filter/antenna systems as well as a filter/antenna array are fabricated and measured. An excellent agreement between the simulated and measured results is observed.
Integration of three‐dimensional high‐Q filters with aperture antennas and bandwidth enhancement utilising surface waves
Authors: Yusuf Yazid , Gong Xun
Published: July 2013

Seamless integration of three‐dimensional cavity filters with a new antenna is presented. The antenna consists of an open‐ended waveguide aperture mounted on a ground plane. The energy coupling between the last cavity resonator and free space, which is related to the external quality (Q) factor of the integrated filter/antenna system, can be significantly enhanced. The low external Q factor (Qext), which is necessary for the design of wide‐band filter/antenna systems, is due to the excitation and radiation of surface waves. A three‐pole cavity filter integrated with the proposed antenna is demonstrated at X band. The centre frequency and fractional bandwidth of the filter/antenna system are 10.2 GHz and 34.0%, respectively, in simulations. A prototype filter/antenna system is fabricated and measured. Good agreement between the simulated and measured results is observed.
Distortion and impairments mitigation and compensation of single‐ and multi‐band wireless transmitters (invited)
Authors: Ghannouchi Fadhel M. , Younes Mayada , Rawat Meenakshi
Published: July 2013

Transmitter digital domain linearisation solutions are constantly evolving to extract optimum benefits in terms of cost, performance and flexibility. This study highlights the current and futuristic trends in the arena of transmitter system modelling and digital domain compensation for radio frequency distortions of non‐linear power amplifiers and wireless transmitters in case of single‐band wireless transmitter, which is further extended to a dual‐band transmitter. Indeed, the dual‐band transmitter results in severe non‐linear distortion as compared to the single‐band transmitter when operated in concurrent mode, due to the additional inter‐modulation products generated by the dual‐band transmitted signals. Hence, in addition to the intermodulation products and memory effects exhibited in a single‐band transmitter, the cross‐modulation effects of the dual‐band signals should be compensated for as well in a dual‐band transmitter. The effects of the modulator imperfections such as gain and phase imbalances, phase errors and DC offsets and their impact on the feedback loop of a digital predistortion system are also analysed. A thorough comparison between the state‐of‐the‐art behavioural models and their application to digital predistortion technique of power amplifier is presented in terms of performance and complexity. Model performance assessment is discussed through simulation and experimental results for both single‐ and dual‐band systems.
Multipath‐dominant analysis of rotating blades using a pulsed waveform
Authors: Robinson Michael
Published: July 2013

Wind turbines present an opportunity for real‐time, clear weather wind observations. By remotely measuring the speed and direction of turbine rotation, one could opportunistically measure wind speed and direction. However, current methods do not allow for rotation direction measurement if one uses a stationary monostatic radar platform. The authors present a novel angular fingerprinting algorithm that fills this gap. Unlike other approaches, the authors assume that the target's centroid is stationary and exploit doppler multipath signals to resolve the otherwise unavoidable ambiguities that arise. Since the algorithm is based on an underlying differential topological theory, it is robust to distortions in the collected data. The authors demonstrate performance of this algorithm experimentally, by exhibiting a pulsed doppler sonar collection system that runs on a smartphone.
Single molecule simulations in complex geometries with embedded dynamic one-dimensional structures
Authors: Hellander Stefan
Published: July 2013

Stochastic models of reaction-diffusion systems are important for the study of biochemical reaction networks where species are present in low copy numbers or if reactions are highly diffusion limited. In living cells many such systems include reactions and transport on one-dimensional structures, such as DNA and microtubules. The cytoskeleton is a dynamic structure where individual fibers move, grow, and shrink. In this paper we present a simulation algorithm that combines single molecule simulations in three-dimensional space with single molecule simulations on one-dimensional structures of arbitrary shape. Molecules diffuse and react with each other in space, they associate with and dissociate from one-dimensional structures as well as diffuse and react with each other on the one-dimensional structure. A general curve embedded in space can be approximated by a piecewise linear curve to arbitrary accuracy. The resulting algorithm is hence very flexible. Molecules bound to a curve can move by pure diffusion or via active transport, and the curve can move in space as well as grow and shrink. The flexibility and accuracy of the algorithm is demonstrated in five numerical examples.
Different-scale convective structures in a cooled liquid layer with a horizontal shear flow
Authors: Reutov V. P. , Rybushkina G. V.
Published: July 2013

The paper is concerned with three-dimensional different-scale convective structures arising in a thin liquid layer cooled from above and subjected to a horizontal shear flow produced by tangent wind stresses on a free surface. In accord with the previous experiment the region of moderately large Grashof and Marangoni numbers and not too large Reynolds numbers is examined. The problem is solved numerically using a spectral method constructed on the basis of a spectral representation of the standard equations governing the gravity-capillary convection. Spectral decomposition with periodicity condition along the horizontal coordinates together with discretization in the vertical direction is used. The planeforms obtained in a horizontal subsurface section of vertical velocity field are analyzed. The mechanism of formation of coherent different-scale structures arising due to surface cooling and thermocapillarity effects is elucidated and the cell-to-roll transition occurring with the increase of horizontal flow velocity is studied. Roll patterns containing longitudinal (aligned in the mean flow direction) basic rolls and predominantly transversal small-scale rolls are revealed. The problem of upflow and downflow cells in question is discussed and the agreement of the computational results with the available experimental data is confirmed.
Erratum: “A characterization of causal automorphisms by wave equations” [J. Math. Phys. 53, 032507 (2012)]
Authors: Kim Min Kyu , Kim Do-Hyung
Published: July 2013

The last part of the proof of Theorem 2.3 in the paper of Kim [J. Math. Phys. 53, 032507 (2012)]10.1063/1.3698288 is corrected. None of the results or conclusions is affected by this error. It is discussed that the proof of Theorem 2.3 in the paper of Kim [J. Math. Phys. 53, 032507 (2012)]10.1063/1.3698288 can be simplified by use of known results. This explains the differences between Minkowski 2-space and higher dimensional Minkowski space, clearly.
Four-vortex motion around a circular cylinder
Authors: Moura Marcel N. , Vasconcelos Giovani L.
Published: July 2013

The motion of two pairs of counter-rotating point vortices placed in a uniform flow past a circular cylinder is studied analytically and numerically. When the dynamics is restricted to the symmetric subspace—a case that can be realized experimentally by placing a splitter plate in the center plane—it is found that there is a family of linearly stable equilibria for same-signed vortex pairs. The nonlinear dynamics in the symmetric subspace is investigated and several types of orbits are presented. The analysis reported here provides new insights and reveals novel features of this four-vortex system, such as the fact that there is no equilibrium for two pairs of vortices of opposite signs on the opposite sides of the cylinder. (It is argued that such equilibria might exist for vortex flows past a cylinder confined in a channel.) In addition, a new family of opposite-signed equilibria on the normal line is reported. The stability analysis for antisymmetric perturbations is also carried out and it shows that all equilibria are unstable in this case.
An ultra-high Q silicon compound cantilever resonator for Young's modulus measurements
Authors: Metcalf Thomas H. , Liu Xiao
Published: July 2013

We describe the design of ultra-high Q mechanical cantilever resonators, fabricated from single-crystal silicon wafers. The mechanical resonance mode at f ≈ 8.5 kHz achieves a background damping of Q−1 ≲ 2 × 10−8 at temperatures below 30 K, which is equal to that of a successful silicon torsional resonator with which the cantilever resonator shares several design elements. The new resonator can be used for accurate measurements of the Young's modulus and internal friction of thin films. It is compatible with both the mounting apparatus and measurement electronics of the torsional resonator, and the two resonators together can be used to provide a complete description of the elastic properties of isotropic thin films.
Piezoelectric micromachined microphones with out-of-plane directivity
Authors: Kim Donghwan , Hewa-Kasakarage Nishshanka N. , Kuntzman Michael L. , Kirk Karen D. , Yoon Sang H. , Hall Neal A.
Published: July 2013

Piezoelectric microphones with out-of-plane directivity are introduced. Structures are comprised of circular diaphragms suspended on compliant circumferential springs and open to ambient at front and back sides. The springs contain thin piezoelectric films for integrated piezoelectric readout. Prototypes are presented in which diaphragm and springs are etched into a 10-μm-thick epitaxial Si layer with 800-nm-thick lead-zirconate-titanate films on the spring surface. Directivity and frequency response measurement confirm anticipated device functionality. A discussion of signal-to-noise ratio (SNR) merits of the approach is presented, concluding that up to 20-dB SNR improvements may be possible beyond what is achievable with present state-of-the-art commercial microphones.
Symbolic methods for the evaluation of sum rules of Bessel functions
Authors: Babusci D. , Dattoli G. , Górska K. , Penson K. A.
Published: July 2013

The use of the umbral formalism allows a significant simplification of the derivation of sum rules involving products of special functions and polynomials. We rederive in this way known sum rules and addition theorems for Bessel functions. Furthermore, we obtain a set of new closed form sum rules involving various special polynomials and Bessel functions. The examples we consider are relevant for applications ranging from plasma physics to quantum optics.
The ordered double perovskite PrBaCo2O6: Synthesis, structure, and magnetism
Authors: Motin Seikh Md. , Pralong V. , Lebedev O. I. , Caignaert V. , Raveau B.
Published: July 2013

The stoichiometric layered perovskite cobaltite PrBaCo2O6 has been synthesized using an oxidative reaction of PrBaCo2O5.80 by sodium hypochlorite. The ferromagnetic properties of this oxide, which exhibits the highest TC of 210 K among the “112” layered cobaltites, are interpreted by double exchange mechanism. In contrast, the creation of oxygen vacancies in this framework leads for the oxides PrBaCo2O5+δ (0.80 ≤ δ < 1) to a strong competition between ferromagnetism and antiferromagnetism due to the appearance of superexchange Co3+—O—Co3+ antiferromagnetic interactions.
Near-infrared quantum cutting in OH− free Nd3+-Yb3+ co-doped low-silica calcium aluminosilicate glasses
Authors: Borrero-González L. J. , Nunes L. A. O. , Bianchi G. S. , Astrath F. B. G. , Baesso M. L.
Published: July 2013

Near-infrared (NIR) quantum cutting (QC) through downconversion (DC) in OH− free Nd3+-Yb3+ co-doped low-silica calcium aluminosilicate glasses (LSCAS) was observed. Luminescence and time-resolved measurements allowed the investigation of the origin of the Yb3+ DC emission. Our results showed that only one NIR photon is emitted by the Yb3+ ion through one-step energy transfer after excitation with a VIS photon absorbed by the Nd3+ ion. However, after excitation with an UV photon absorbed by the Nd3+ ion, two NIR photons are emitted by the Yb3+ ion through two-step energy transfer. The Yb3+ DC normalized intensities after excitation at 325 nm showed an increase of a factor of two compared to that of 514 nm excitation. In addition, the energy transfer probabilities from Nd3+ to Yb3+ were estimated by analyzing the Yb3+ DC kinetics. The overall results showed an efficient QC through DC process in Nd3+-Yb3+ co-doped LSCAS glasses, and the energy transfer mechanisms are discussed.
Transverse domain wall scattering and pinning by magnetic impurities in magnetic nanowires
Authors: Ferreira V. A. , Toscano D. , Leonel S. A. , Coura P. Z. , Dias R. A. , Sato F.
Published: July 2013

We used numerical simulations to study the dynamical behavior of the transverse domain wall (TDW) in nanowires made of Permalloy-79 contaminated by pointlike magnetic impurities. It was observed that the magnetic impurities can behave both as pinning (attractive) and as scattering (repulsive) sites for the TDW. We have found that the nearer to the bottom edge of the nanowire is located the magnetic impurity, the larger is the magnitude of the pinning and the scattering energy, which agrees with experimental observation. We also observed that the interaction energy and the range of the interaction potential depend on the width of the nanowire. The presence of magnetic impurity affects the motion of the TDW.
TiO2-Au nanocomposite materials modified photoanode with dual sensitizer for solid-state dye-sensitized solar cell
Authors: Pandikumar Alagarsamy , Ramaraj Ramasamy
Published: July 2013

The dual-photosensitizer consisting of cadmium sulphide quantum dots (CdS QDs) and basic blue-3 (BB-3) was employed in a solid-state dye-sensitized solar cell (DSSC) composed of aminosilicate sol-gel functionalized titanium dioxide-gold nanocomposite material (EDAS/(P25-Au)nps) photoanode and degussa-TiO2 (P25) nanoparticles incorporated poly(ethylene oxide) polymer electrolyte (PEO-P25-KI-I2). The UV-vis spectral analysis revealed that a large part of visible light is absorbed by the dual-photosensitizer (BB-3 + CdS QDs), particularly in the red region of the solar spectrum, and as a result the DSSC showed improved solar to electrical energy conversion efficiency of 0.37% under simulated AM 1.5G at 100 mW cm−2 solar irradiation. The photovoltaic performance of (BB-3 + CdS QDs) sensitized solid-state DSSC was compared to the BB-3 sensitized solar cell, in which the former exhibited around ∼3-fold increase in the overall solar to electrical energy conversion efficiency than that of the later. The solar to electrical energy conversion efficiency of the standard N719 dye sensitized DSSC was found to be higher than the dual sensitizer (BB-3 + CdS QDs) employed solid-state DSSC.
Urban Infrastructure Dynamics: Market Regulation and the Shaping of District Energy in UK Cities
Authors: Bolton Ronan , Foxon Timothy J
Published: July 2013

This paper explores the interaction between urban-scale energy infrastructure and the regulatory regime which underpins the liberalisation of energy systems. Using the example of district energy in a number of UK cities, we outline the ways in which the structure of national electricity markets and the activities of the energy regulator influence and shape the development of low-carbon infrastructure in cities. We draw upon recent contributions to the sociotechnical systems literature which highlights the role of cities in shaping infrastructure transitions and argue that the influence of sector regulation has been underrepresented and underexplored. Our study points to significant tensions and misalignments between a regulatory regime designed to promote economic efficiencies in incumbent national infrastructure sectors and the development of district energy systems at the urban scale. We propose that regulation needs to evolve from its traditional emphasis on promoting competition and short-term efficiencies towards a more dynamic model which is open to alternative logics and low-carbon transition pathways.
Complexation of Crystal Violet, Pyronine B, and Rhodamine B by Linked β-Cyclodextrin Trimers
Authors: Nguyen Hanh-Trang , Pham Duc-Truc , Easton Christopher J. , Lincoln Stephen F.
Published: July 2013

The host-guest complexation by β-cyclodextrin (βCD), 1,3,5-N,N,N-tris-(6A-deoxy-6A-β-cyclodextrin)-benzene (βCD3bz), and 1,3,5-N,N,N-tris(6A-(2-aminoethyl)amino-6A-deoxy-6A-β-cyclodextrin)-benzene (βCDen3bz) of cationic crystal violet (CV+) and pyronine B (PB+) and zwitterionic rhodamine B (RB) in aqueous phosphate buffer at pH 7.0 and I = 0.10 mol dm–3 has been studied by UV-Vis and 1H NMR spectroscopy. The complexation constants 10–3K1 (298.2 K) are 4.68, 86.3, and 7.08 dm3 mol–1 for the 1 : 1 host-guest complexes: βCD.CV+, βCD3bz.CV+, βCDen3bz.CV+, respectively, and those for the analogous PB+ and RB complexes have also been determined. The associated ΔHo and TΔSo for all nine complexes coincide with an entropy-enthalpy compensation plot for the formation of a wide range of βCD and modified βCD host-guest complexes reported in the literature. Crystal violet also forms (βCD)2.CV+, (βCD3bz)2.CV+ and (βCDen3bz)2.CV+ complexes characterised by 10–2K2 (298.2 K) = 2.14, 4.57, and 3.86 dm3 mol–1 and analogous (βCD)2.PB+, (βCDen3bz)2.PB+ and (βCDen3bz)2.RB complexes also form, but the (βCD3bz)2.PB+, (βCD)2.RB, and (βCD3bz)2.RB complexes were not detected. The effects of the structures of the hosts and guests on the complexation processes are discussed.
Leveraging changing gender norms to address concurrency: focus group findings from South African university students
Authors: Psaki Stephanie R. , Ayivi-Guedehoussou Nono , Halperin Daniel T.
Published: July 2013

Background This study aims to complement recent research on sexual concurrency in South Africa by providing a deeper understanding of women’s roles and motivations for engaging in and accepting their partners’ concurrency. Our goal is to inform the implementation of more effective interventions that embrace the powerful role that women can play in healthy sexual decision-making in consensual relationships. Methods: We conducted 12 focus groups with male and female students at the University of KwaZulu-Natal. Drawing on a subset of those focus groups, we examined the gender norms underpinning the apparently widespread acceptance of concurrent sexual partnerships. Our analysis focusses on women’s attitudes and behaviours towards concurrency – from both men’s and women’s perspectives – with a goal of identifying opportunities to engage women as agents of change in sexual partnership patterns in their communities. Results: Our findings indicate that: (1) concurrent sexual partnerships were the norm among male students and increasingly common among female students; (2) material gain and changes in women’s perceptions of their roles and power in relationships were the primary female motives for concurrency; (3) peer pressure, a perceived innate need and a fear of being alone were the primary male motives for concurrency; (4) women often know that their partners are cheating and stay with them because they believe they are the most important partner, for financial reasons, or because they worry they will not find another partner. Conclusions: HIV prevention interventions in populations where concurrency is common would benefit from emphasising women’s role and power in taking greater control of their own sexual decision-making in consensual and nonviolent relationships.
On the Julia set of König’s root–finding algorithms
Authors: Honorato Gerardo
Published: July 2013

As is well known, the Julia set of Newton’s method applied to complex polynomials is connected. The family of König’s root–finding algorithms is a natural generalization of Newton’s method. We show that the Julia set of König’s root–finding algorithms of order

σ
≥
3

\sigma \geq 3

applied to complex polynomials is not always connected.
A Borel-Cantelli lemma and its applications
Authors: Luzia Nuno
Published: July 2013

We give a version of the Borel-Cantelli lemma. As an application, we prove an almost sure local central limit theorem. As another application, we prove a dynamical Borel-Cantelli lemma for systems with sufficiently fast decay of correlations with respect to Lipschitz observables.
Comparative genomics as a tool to understand evolution and disease
Authors: Alföldi Jessica , Lindblad-Toh Kerstin
Published: July 2013

When the human genome project started, the major challenge was how to sequence a 3 billion letter code in an organized and cost-effective manner. When completed, the project had laid the foundation for a huge variety of biomedical fields through the production of a complete human genome sequence, but also had driven the development of laboratory and analytical methods that could produce large amounts of sequencing data cheaply. These technological developments made possible the sequencing of many more vertebrate genomes, which have been necessary for the interpretation of the human genome. They have also enabled large-scale studies of vertebrate genome evolution, as well as comparative and human medicine. In this review, we give examples of evolutionary analysis using a wide variety of time frames—from the comparison of populations within a species to the comparison of species separated by at least 300 million years. Furthermore, we anticipate discoveries related to evolutionary mechanisms, adaptation, and disease to quickly accelerate in the coming years.
Immunoblotting Histones from Yeast Whole-Cell Protein Extracts
Authors: Rossmann Marlies P. , Stillman Bruce
Published: July 2013

Histones are small basic proteins that are core components of chromatin. As such, they are essential for cell viability and genomic stability and their levels are tightly controlled. In addition, histone tails are subject to extensive posttranslational modifications, including acetylation, methylation, phosphorylation and ubiquitylation, that play critical roles in many cellular processes. To quickly screen for alterations in histone levels and/or their modifications in yeast mutants under different growth conditions, we present a fast and reliable protocol for whole-cell protein extract preparation and immunoblotting.
Measuring Interstitial pH and pO2 in Mouse Tumors
Authors: Jain Rakesh K. , Munn Lance L. , Fukumura Dai
Published: July 2013

This protocol outlines methods to measure two extravascular parameters, interstitial pH and partial pressure of oxygen (pO2), in mouse tumors. The method for measuring interstitial pH uses fluorescence ratio imaging microscopy (FRIM) of the pH-sensitive fluorescent dye 2′,7′-bis-(2-carboxyethyl)-5,6-carboxyfluorescein (BCECF). The method for measuring interstitial pO2 is based on the oxygen-dependent quenching of the phosphorescence of albumin-bound palladium meso-tetra(4-carboxyphenyl)porphyrin, and can be used to measure microvascular as well as interstitial pO2. In addition, the two methods can be used sequentially to measure both pH and pO2 in the same tissues.
Dehydration and Clearing of Whole Mouse Brains and Dissected Hippocampi for Ultramicroscopy
Authors: Becker Klaus , Jährling Nina , Saghafi Saiedeh , Dodt Hans-Ulrich
Published: July 2013

This protocol describes the preparation of whole mouse brains and dissected hippocampi for ultramicroscopy (UM), a powerful imaging technique that achieves precise and accurate three-dimensional (3D) reconstructions of intact macroscopic specimens with micrometer resolution. In UM, a specimen in the size range of ∼1–15 mm is illuminated perpendicular to the observation pathway by two thin counterpropagating sheets of laser light. Thus, specimens for UM need to be sufficiently transparent, which requires chemical clearing in most cases. In this protocol, mouse brains and hippocampi are carefully dissected and dehydrated, and then cleared in a solution of benzyl benzoate and benzyl alcohol.
Interpreting Statutory Purpose – Lessons from Yemshaw v Hounslow London Borough Council
Authors: Bevan Chris
Published: July 2013

Yemshaw v Hounslow LBC is a significant case in the fields of housing and family law, as well as giving rise to important issues as to the judicial role and statutory interpretation more broadly. This note critically analyses the reasoning of the Supreme Court in Yemshaw, in which the principal issue was whether the definition of ‘violence’ for the purposes of the Housing Act 1996 extended to non‐physical as well as physical forms of harm. In rejecting the view of the Court of Appeal, the Supreme Court adopted a wider definition of violence to encompass emotional and psychological as well as financial abuse. This commentary adopts a fresh stance by examining closely the context surrounding the enactment of the Housing Act 1996 and how this informs the question of statutory interpretation. In so doing, the author suggests that the interpretation employed by the court is significantly undermined.
Metabolic potential of the organic‐solvent tolerant Pseudomonas putida DOT‐T1E deduced from its annotated genome
Authors: Udaondo Zulema , Molina Lazaro , Daniels Craig , Gómez Manuel J. , Molina‐Henares María A. , Matilla Miguel A. , Roca Amalia , Fernández Matilde , Duque Estrella , Segura Ana , Ramos Juan Luis
Published: July 2013

Pseudomonas putida DOT‐T1E is an organic solvent tolerant strain capable of degrading aromatic hydrocarbons. Here we report the DOT‐T1E genomic sequence (6 394 153 bp) and its metabolic atlas based on the classification of enzyme activities. The genome encodes for at least 1751 enzymatic reactions that account for the known pattern of C, N, P and S utilization by this strain. Based on the potential of this strain to thrive in the presence of organic solvents and the subclasses of enzymes encoded in the genome, its metabolic map can be drawn and a number of potential biotransformation reactions can be deduced. This information may prove useful for adapting desired reactions to create value‐added products. This bioengineering potential may be realized via direct transformation of substrates, or may require genetic engineering to block an existing pathway, or to re‐organize operons and genes, as well as possibly requiring the recruitment of enzymes from other sources to achieve the desired transformation.