bluuebunny/crossref_metadata_2025 huggingface dataset:
Best management practices for forest bioenergy programs
Authors: Neary Daniel G.
Published: May 2013

Forest ecosystems produce the best quality and most consistent supplies of water for human use. The increase in the use of woody biomass as a feedstock for bioenergy production has raised questions about potential impacts on water quality. Best management practices (BMPs) have been developed and implemented since the early 1970s to ensure that forest harvesting can be conducted with minimum impact on water quality. AlthoughBMPs were originally designed to minimize water quality impacts, they can be used for a variety of environmental concerns. The use ofBMPs is widespread in developed countries and it varies from mandatory to voluntary. In many countriesBMPs are incorporated in ‘Codes of Forest Practice’ that guide forest managers through the complete bioenergy life cycle. The development and application of BMPs is not a static process, but one that relies on a continual cycle of application, assessment and monitoring, and refinement. Although some countries have “national standards,“ the complex matrix of forest ecosystems, climates, soils and topography, and harvesting systems requires ongoing assessment, monitoring, and refinement to craftBMPs to best suit local conditions. Research and development studies play a key part in the refinement and communication of improvedBMPs. They are also crucial in validating the effectiveness ofBMPs. This is especially important where local environmental conditions or operational standards are unique.BMPs ensure that forest bioenergy programs can be a sustainable part of forest management and renewable energy production.

This article is categorized under:

Bioenergy > Science and Materials

Bioenergy > Climate and Environment
Valuing preferences over stormwater management outcomes including improved hydrologic function
Authors: Londoño Cadavid Catalina , Ando Amy W.
Published: May 2013

Stormwater runoff causes environmental problems such as flooding, soil erosion, and water pollution. Conventional stormwater management has focused primarily on flood reduction, while a new generation of decentralized stormwater solutions yields ancillary benefits such as healthier aquatic habitat, improved surface water quality, and increased water table recharge. Previous research has estimated values for flood reduction from stormwater management, but no estimates exist for the willingness to pay (WTP) for some of the other environmental benefits of alternative approaches to stormwater control. This paper uses a choice experiment survey of households in Champaign‐Urbana, Illinois, to estimate the values of several attributes of stormwater management outcomes. We analyzed data from 131 surveyed households in randomly selected neighborhoods. We find that people value reduced basement flooding more than reductions in yard or street flooding, but WTP for basement flood reduction in the area only exists if individuals are currently experiencing significant flooding themselves. Citizens value both improved water quality and improved hydrologic function and aquatic habitat from runoff reduction. Thus, widespread investment in low impact development stormwater solutions could have very large total benefits, and stormwater managers should be wary of policies and infrastructure plans that reduce flooding at the expense of water quality and aquatic habitat.
Representing atmospheric moisture content along mountain slopes: Examination using distributed sensors in the Sierra Nevada, California
Authors: Feld Shara I. , Cristea Nicoleta C. , Lundquist Jessica D.
Published: May 2013

Atmospheric moisture content is critical in hydrological modeling yet is sparsely measured in mountainous environments. We compared densely distributed measurements of dew point temperature in two study sites in the Sierra Nevada, California, against (1) simple empirical algorithms, (2) the Parameter‐elevation Regressions on Independent Slopes Model (PRISM), (3) radiosonde data, and (4) the Weather Research and Forecasting (WRF) mesoscale model. Empirical algorithms that used only one sea‐level measurement of dew point to extrapolate to higher elevations often did not match local dew point lapse rates and could be biased as high as 9.9°C. PRISM improved upon these methods by using local observations to determine the local average dew point lapse rate, with median bias values of −0.3°C and 3.3°C in our two study sites. Empirical algorithms that derived dew point from air temperature showed a seasonal variation in performance; summer median bias values were 0.6°C–8.2°C wetter than winter bias values. Radiosonde readings showed median biases of −6.5°C and −8.0°C from observations in our study sites. WRF improved on the radiosonde data, performing well in representing both the overall trends in the basin (with median biases of −0.9°C and −1.0°C in our study sites). One base station within the basin paired with PRISM lapse rates showed small biases from overall moisture trends. However, a physically resolved model such as WRF was better equipped to represent daily dew point variations and in basins with nonlinear trends.
Editorial: political abuse of psychiatry in authoritarian systems
Authors: Tobin J. P.
Published: May 2013

We are painfully aware: Psychiatry in some states of the international community is often used to subvert the political and legal guarantees of the freedom of the individual and to violate seriously his human and legal rights (Daes,1986).

Objective

It can be politically convenient to incarcerate political opponents in a psychiatric hospital. It saves any potential political embarrassment that a judicial trial may present. It also undermines the credibility of opponents by labelling them with the stigma of being mentally insane. For this to occur, there has to be the acquiescence of mental health professionals and a subservient legal system.

Method

This article examines the abuse of psychiatry in two authoritarian systems, Russia and China.

Result

New diagnostic categories such as sluggish schizophrenia were created to facilitate the silencing of dissenters and were a source of self-deception for psychiatrist to placate their consciences as they operated as a tool of oppression on behalf of a political system.

Conclusion

If we do not know the past, we will be condemned to repeat it.
On lambda operations on mixed motives
Authors: Biglari Shahram
Published: May 2013

We study the natural λ-ring structure on the Grothendieck ring of the triangulated category of mixed motives. Basic properties of a natural notion of characteristic-like series are developed in the context of equivariant objects.
Meta-analysis of the HTR2A–1354C/T polymorphism in schizophrenia and bipolar disorder
Authors: Gu Lian , Tan Jinjing , Su Li , Qin Yuwang , Long Jianxiong , Chen Qing , Xie Juanjuan , liang Baoyun , Yan Yan , Wu Guangliang
Published: May 2013

Objective

Schizophrenia (SCZ) and bipolar disorder (BD) are common psychotic disorders, which show some overlaps in genetic aetiology. Researchers have conducted a number of studies to investigate the relationship between SCZ and the 1354C/T genetic polymorphism of 5-hydroxytryptamine receptor 2A (HTR2A–1354C/T), as well as the associations between BD and the HTR2A–1354C/T polymorphism. However, the results were conflicting. To provide a more robust estimate about the effects of the HTR2A–1354C/T polymorphism on the risk of these two psychotic disorders, we performed this meta-analysis.

Methods

We used the pooled odds ratios (ORs) with 95% confidence intervals (95% CIs) to investigate the relationships between SCZ and the 1354C/T polymorphism of HTR2A, as well as the associations between BD and HTR2A–1354C/T. Publication bias was tested by Begg's test and inverted funnel plot, and heterogeneity was checked by Cochran's Q statistic and the inconsistency index (I2).

Results

Eight studies were concerned with SCZ, analysing a cumulative total of 2953 cases and 3153 controls; six papers studied BD, using a total of 923 cases and 928 controls. There was no significant association found between HTR2A–1354C/T and SCZ in the overall population (T allele vs. C allele, OR = 1.035, 95% CI 0.912–1.175, p = 0.596) or in the subgroups Caucasian population and Asian population. Moreover, there was no significant association between the HTR2A–1354C/T polymorphism and BD in the overall population (T allele vs. C allele, OR = 1.038, 95% CI = 0.607–1.772, p = 0.892).

Conclusion

On the basis of these results, the HTR2A–1354C/T polymorphism is unlikely to be a risk factor for SCZ and BD.
The Structure of Galaxies: II. Fitting Functions and Scaling Relations for Ellipticals
Authors: Schombert J. M.
Published: May 2013

Surface photometry of 311 ellipticals from the 2MASS imaging database is analyzed with respect to the two most common fitting functions: the r1/4 law and the Sérsic r1/n model. The advantages and disadvantages of each fitting function are examined. In particular, the r1/4 law performs well in the middle regions, but is inadequate for the core (inner 5 kpc) and the outer regions (beyond the half-light radius) which do not have r1/4 shapes. It is found that the Sérsic r1/n model produces good fits to the core regions of ellipticals (r<rhalf), but is an inadequate function for the entire profile of an elliptical from core to halo due to competing effects on the Sérsic n index and the fact that the interior shape of an elliptical is only weakly correlated with its halo shape. In addition, there are a wide range of Sérsic parameters that will equally describe the shape of the outer profile, degrading the Sérsic model's usefulness as a describer of the entire profile. Empirically determined parameters, such as half-light radius and total luminosity, have less scatter than fitting function variables. The scaling relations for ellipticals are often non-linear, but for ellipticals brighter than MJ < −23 the following structural relations are found: L ∝ r0.8±0.1, L ∝ Σ−0.5±0.1, and Σ ∝ r−1.5±0.1.
The cat as a model for human obesity: insights into depot-specific inflammation associated with feline obesity
Authors: Van de Velde H. , Janssens G. P. J. , de Rooster H. , Polis I. , Peters I. , Ducatelle R. , Nguyen P. , Buyse J. , Rochus K. , Xu J. , Verbrugghe A. , Hesta M.
Published: May 2013

According to human research, the location of fat accumulation seems to play an important role in the induction of obesity-related inflammatory complications. To evaluate whether an inflammatory response to obesity depends on adipose tissue location, adipokine gene expression, presence of immune cells and adipocyte cell size of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) were compared between lean and obese cats. Additionally, the present study proposes the cat as a model for human obesity and highlights the importance of animal models for human research. A total of ten chronically obese and ten lean control cats were included in the present study. Body weight, body condition score and body composition were determined. T-lymphocyte, B-lymphocyte, macrophage concentrations and adipocyte cell size were measured in adipose tissue at different locations. Serum leptin concentration and the mRNA expression of leptin and adiponectin, monocyte chemoattractant protein-1, chemoligand-5, IL-8, TNF-α, interferon-γ, IL-6 and IL-10 were measured in blood and adipose tissues (abdominal and inguinal SAT, and omental, bladder and renal VAT). Feline obesity was characterised by increased adipocyte cell size and altered adipokine gene expression, in favour of pro-inflammatory cytokines and chemokines. Consequently, concentration of T-lymphocytes was increased in the adipose tissue of obese cats. Alteration of adipose tissue was location dependent in both lean and obese cats. Moreover, the observed changes were more prominent in SAT compared with VAT.
BonJour’s Way Out of the Sellarsian Dilemma and his Explanatory Account
Authors: LEE BYEONG D.
Published: May 2013

BonJour claims that he has found a way out of the Sellarsian dilemma. In this paper, I argue for three claims to show that his alleged solution fails. First, there are two requirements for being a good reason, and BonJour’s notion of non-conceptual awareness of sensory experience faces a serious dilemma with regard to these requirements. Second, he derives his idea of the so-called “constitutive awareness of content” from his conception of conscious occurrent belief. But this conception also faces an analogous dilemma with regard to these requirements. Third, his explanatory account faces the problem of representation.
Best linear unbiased prediction for genetic evaluation in reciprocal recurrent selection with popcorn populations
Authors: VIANA J. M. S. , MUNDIM G. B. , DELIMA R. O. , E SILVA F. F. , DE RESENDE M. D. V.
Published: May 2013

The objective of the present study was to present the theory and application of best linear unbiased prediction (BLUP) in reciprocal recurrent selection (RRS). Seven progeny tests from two RRS programmes with popcorn (Zea mays L. ssp. mays [syn. Zea mays L. ssp. everta (Sturtev.) Zhuk.]) populations were conducted and analysed for expansion volume and grain yield. The interpopulation half- and full-sib family models were fitted using ASReml software. Half-sib selection is equivalent to selection for the general combining ability (GCA) of the common parents. With inbred full-sib progeny and BLUP analysis, it is possible to predict the general and specific combining ability effects. The standard error of prediction of the progeny effect was lower than the standard deviation of the best linear unbiased estimation (BLUE) estimate. For half- and full-sib RRS, the BLUE and BLUP provided highly correlated estimates of progeny genotypic values. The coincidence between selected parents ranged from 64 to 95%. With inbred full-sib progeny, the correlations between the BLUE of progeny genotypic values and the BLUP of GCA effects were lower. Consequently, the coincidence between selected parents was lower, ranging from 0 to 57%. The percentage of common selected inbred progeny based on the BLUE and BLUP of the progeny genotypic value ranged from 57 to 100%.
Political Extremism in the 1920s and 1930s: Do German Lessons Generalize?
Authors: de Bromhead Alan , Eichengreen Barry , O'Rourke Kevin H.
Published: May 2013

We examine the impact of the Great Depression on the share of votes for right-wing extremists in elections in the 1920s and 1930s. We confirm the existence of a link between political extremism and economic hard times as captured by growth or contraction of the economy. What mattered was not simply growth at the time of the election, but cumulative growth performance. The impact was greatest in countries with relatively short histories of democracy, with electoral systems that created low hurdles to parliamentary representation, and which had been on the losing side in World War I.
Container Slot Co-Allocation Planning with Joint Fleet Agreement in a Round Voyage for Liner Shipping
Authors: Chen Jihong , Yahalom Shmuel
Published: May 2013

In the liner shipping market carriers share container slots to offer better service and realize economies of scale. This paper studies slot co-allocation planning for a joint fleet in a round trip for a shipping alliance in the liner shipping industry. In particular, a conceptual model is developed based on joint fleet and slot co-allocation management. The factors affecting slot co-allocation planning are explored in detail. A large-scale integer programming model is formulated to guide carriers in an alliance in pursuing an optimal slot co-allocation strategy. In contrast to the existing research, this approach leads to a more accurate representation of the situation for cooperative services in the liner shipping market. Extensive numerical experiments based on a true Asia-Europe cooperative route of COSCO and HANJIN show that the proposed model can be efficiently solved by LINGO11.0 for the case study. The computational results suggest that the mechanism and model can be used to benefit carriers in making better decisions in shipping cooperation services.
Health Care Services Use in Assisted Living: A Time Series Analysis
Authors: McGrail Kimberlyn M. , Lilly Meredith B. , McGregor Margaret J. , Broemeling Anne-Marie , Salomons Kia , Peterson Sandra , McKendry Rachael , Barer Morris L.
Published: May 2013

Cet article décrit le modèle réglementaire de la Colombie-Britannique pour l’aide à la vie autonome et était basée sur une analyse des séries chronologiques qui a examiné l’utilisation individuelle des services de soins de santé avant et après leur arrivée en résidence-services. Les 4 219 résidents étudiés dans résidences assistées étaient vieilles et surtout des femmes, 73 pour cent d’entre eux ayant une ou plusieurs principales maladies chroniques. L’utilisation des services de soins de santé a eu la tendance à augmenter avant le passage à la vie autonome, de diminuer au moment du déménagement (notamment pour les médecins généralistes, les médecins spécialistes, et les soins actifs), et de rester faible au cours des 12 mois de la période suivie. Ces effets positifs apparents ne sont pas insignifiantes; la cohorte de 1 894 résidents de la vie assistée utilisaient moins de 18 000 jours de soins actifs dans l’année après, par rapport à l’année précédente, de leur déménagement. La recherche dans l’avenir devrait examiner si et comment aide à la vie autonome affecte à long terme les voies de soins de santé pour les personnes âgées et, finalement, comment leur fonction et la qualité de la vie sont touchés.
Biological soil crusts in continental Antarctica: Garwood Valley, southern Victoria Land, and Diamond Hill, Darwin Mountains region
Authors: Colesie Claudia , Gommeaux Maxime , Green T.G. Allan , Büdel Burkhard
Published: May 2013

Biological soil crusts are associations of lichens, mosses, algae, cyanobacteria, microfungi and bacteria in different proportions forming a thin veneer within the top centimetres of soil surfaces. They occur in all biomes, but particularly in arid and semi-arid regions, even in the most extreme climates. They carry out crucial ecosystem functions, such as soil stabilization, influencing water and nutrient cycles, and contribute to the formation of microniches for heterotrophic life. In continental Antarctica especially, these roles are essential because no higher plants provide such ecosystem services. We provide a detailed description of biological soil crusts from Garwood Valley, McMurdo Dry Valleys region (78°S) and Diamond Hill (80°S) in the Darwin Mountains region. The coverage was low at 3.3% and 0.8% of the soil surface. At Garwood Valley the crusts were composed of green algal lichens, cyanobacteria, several species of green algae and the mossHennediella heimii(Hedw.) R.H. Zander. Diamond Hill crusts appear to be unique in not having any species of cyanobacteria. Major parts are embedded in the soil, and their thickness correlates with higher chlorophyll contents, higher soil organic carbon and nitrogen, which are fundamental components of this species poor cold desert zone.
Characterization of Inertial Confinement Fusion (ICF) Targets Using PIXE, RBS, and STIM Analysis
Authors: Li Yongqiang , Liu Xue , Li Xinyi , Liu Yiyang , Zheng Yi , Wang Min , Shen Hao
Published: May 2013

Quality control of the inertial confinement fusion (ICF) target in the laser fusion program is vital to ensure that energy deposition from the lasers results in uniform compression and minimization of Rayleigh–Taylor instabilities. The technique of nuclear microscopy with ion beam analysis is a powerful method to provide characterization of ICF targets. Distribution of elements, depth profile, and density image of ICF targets can be identified by particle-induced X-ray emission, Rutherford backscattering spectrometry, and scanning transmission ion microscopy. We present examples of ICF target characterization by nuclear microscopy at Fudan University in order to demonstrate their potential impact in assessing target fabrication processes.
A critical review and re-assessment of theories of smallholder decision-making: a case of conservation agriculture households, Zambia
Authors: Umar Bridget Bwalya
Published: May 2013

Different theories have been posited that try to explain the decision-making process of smallholders especially regarding the adoption of new technologies or new agricultural techniques. The objective of this paper is to review and re-assess the dominant household production theories to explain the decision making of smallholders practicing conservation agriculture (CA) in the southern, eastern, and central provinces of Zambia. It also discusses the potential role of CA toward economic development. It finds that the CA smallholders studied did not aim to maximize profits but tried to secure household consumption from their own production before any other considerations in risky and uncertain environments. Their response to economic incentives was contingent on minimizing risks associated with securing a minimum level of livelihood and investing into local forms of insurance. This paper concludes that the ability for CA to contribute to rural livelihoods and economic development would depend on how adequately the factors that hinder smallholder agricultural development in general are addressed.
Community transcriptomic assembly reveals microbes that contribute to deep-sea carbon and nitrogen cycling
Authors: Baker Brett J , Sheik Cody S , Taylor Chris A , Jain Sunit , Bhasi Ashwini , Cavalcoli James D , Dick Gregory J
Published: May 2013

The deep ocean is an important component of global biogeochemical cycles because it contains one of the largest pools of reactive carbon and nitrogen on earth. However, the microbial communities that drive deep-sea geochemistry are vastly unexplored. Metatranscriptomics offers new windows into these communities, but it has been hampered by reliance on genome databases for interpretation. We reconstructed the transcriptomes of microbial populations from Guaymas Basin, in the deep Gulf of California, through shotgun sequencing and de novo assembly of total community RNA. Many of the resulting messenger RNA (mRNA) contiguous sequences contain multiple genes, reflecting co-transcription of operons, including those from dominant members. Also prevalent were transcripts with only limited representation (2.8 times coverage) in a corresponding metagenome, including a considerable portion (1.2 Mb total assembled mRNA sequence) with similarity (96%) to a marine heterotroph, Alteromonas macleodii. This Alteromonas and euryarchaeal marine group II populations displayed abundant transcripts from amino-acid transporters, suggesting recycling of organic carbon and nitrogen from amino acids. Also among the most abundant mRNAs were catalytic subunits of the nitrite oxidoreductase complex and electron transfer components involved in nitrite oxidation. These and other novel genes are related to novel Nitrospirae and have limited representation in accompanying metagenomic data. High throughput sequencing of 16S ribosomal RNA (rRNA) genes and rRNA read counts confirmed that Nitrospirae are minor yet widespread members of deep-sea communities. These results implicate a novel bacterial group in deep-sea nitrite oxidation, the second step of nitrification. This study highlights metatranscriptomic assembly as a valuable approach to study microbial communities.
Finite Element Analysis and Biomechanical Comparison of Short Posterior Spinal Instrumentation with Divergent Bridge Construct versus Parallel Tension Band Construct for Thoracolumbar Spine Fractures
Authors: Ouellet Jean A. , Richards Corey , Sardar Zeeshan M. , Giannitsios Demetri , Noiseux Nicholas , Strydom Willem S. , Reindl Rudy , Jarzem Peter , Arlet Vincent , Steffen Thomas
Published: May 2013

The ideal treatment for unstable thoracolumbar fractures remains controversial with posterior reduction and stabilization, anterior reduction and stabilization, combined posterior and anterior reduction and stabilization, and even nonoperative management advocated. Short segment posterior osteosynthesis of these fractures has less comorbidities compared with the other operative approaches but settles into kyphosis over time. Biomechanical comparison of the divergent bridge construct versus the parallel tension band construct was performed for anteriorly destabilized T11–L1 spine segments using three different models: (1) finite element analysis (FEA), (2) a synthetic model, and (3) a human cadaveric model. Outcomes measured were construct stiffness and ultimate failure load. Our objective was to determine if the divergent pedicle screw bridge construct would provide more resistance to kyphotic deforming forces. All three modalities showed greater stiffness with the divergent bridge construct. The FEA calculated a stiffness of 21.6 N/m for the tension band construct versus 34.1 N/m for the divergent bridge construct. The synthetic model resulted in a mean stiffness of 17.3 N/m for parallel tension band versus 20.6 N/m for the divergent bridge (p = 0.03), whereas the cadaveric model had an average stiffness of 15.2 N/m in the parallel tension band compared with 18.4 N/m for the divergent bridge (p = 0.02). Ultimate failure load with the cadaveric model was found to be 622 N for the divergent bridge construct versus 419 N (p = 0.15) for the parallel tension band construct. This study confirms our clinical experience that the short posterior divergent bridge construct provides greater stiffness for the management of unstable thoracolumbar fractures.
The Role of the Vertebral End Plate in Low Back Pain
Authors: Lotz J. C. , Fields A. J. , Liebenberg E. C.
Published: May 2013

End plates serve as the interface between rigid vertebral bodies and pliant intervertebral disks. Because the lumbar spine carries significant forces and disks don't have a dedicated blood supply, end plates must balance conflicting requirements of being strong to prevent vertebral fracture and porous to facilitate transport between disk cells and vertebral capillaries. Consequently, end plates are particularly susceptible to damage, which can increase communication between proinflammatory disk constituents and vascularized vertebral bone marrow. Damaged end plate regions can be sites of reactive bone marrow lesions that include proliferating nerves, which are susceptible to chemical sensitization and mechanical stimulation. Although several lines of evidence indicate that innervated end plate damage can be a source of chronic low back pain, its role in patients is likely underappreciated because innervated damage is poorly visualized with diagnostic imaging. This literature review summarizes end plate biophysical function and aspects of pathologic degeneration that can lead to vertebrogenic pain. Areas of future research are identified in the context of unmet clinical needs for patients with chronic low back pain.
A combined DFT and restricted open-shell configuration interaction method including spin-orbit coupling: Application to transition metal L-edge X-ray absorption spectroscopy
Authors: Roemelt Michael , Maganas Dimitrios , DeBeer Serena , Neese Frank
Published: May 2013

A novel restricted-open-shell configuration interaction with singles (ROCIS) approach for the calculation of transition metal L-edge X-ray absorption spectra is introduced. In this method, one first calculates the ground state and a number of excited states of the non-relativistic Hamiltonian. By construction, the total spin is a good quantum number in each of these states. For a ground state with total spin S excited states with spin S′ = S, S − 1, and S + 1 are constructed. Using Wigner-Eckart algebra, all magnetic sublevels with MS = S, …, −S for each multiplet of spin S are obtained. The spin-orbit operator is represented by a mean-field approximation to the full Breit-Pauli spin-orbit operator and is diagonalized over this N-particle basis. This is equivalent to a quasi-degenerate treatment of the spin-orbit interaction to all orders. Importantly, the excitation space spans all of the molecular multiplets that arise from the atomic Russell-Saunders terms. Hence, the method represents a rigorous first-principles approach to the complicated low-symmetry molecular multiplet problem met in L-edge X-ray absorption spectroscopy. In order to gain computational efficiency, as well as additional accuracy, the excitation space is restricted to single excitations and the configuration interaction matrix is slightly parameterized in order to account for dynamic correlation effects in an average way. To this end, it is advantageous to employ Kohn-Sham rather than Hartree-Fock orbitals thus defining the density functional theory/ROCIS method. However, the method can also be used in an entirely non-empirical fashion. Only three global empirical parameters are introduced and have been determined here for future application of the method to any system containing any transition metal. The three parameters were carefully calibrated using the L-edge X-ray absorption spectroscopy spectra of a test set of coordination complexes containing first row transition metals. These parameters are universal and transferable. Hence, there are no adjustable parameters that are used to fit experimental X-ray absorption spectra. Thus, the new approach classifies as a predictive first-principles method rather than an analysis tool. A series of calculations on transition metal compounds containing Cu, Ti, Fe, and Ni in various oxidation and spin states is investigated and a detailed comparison to experimental data is reported. In most cases, the approach yields good to excellent agreement with experiment. In addition, the origin of the observed spectral features is discussed in terms of the electronic structure of the investigated compounds.
The two-loop sunrise graph with arbitrary masses
Authors: Adams Luise , Bogner Christian , Weinzierl Stefan
Published: May 2013

We discuss the analytical solution of the two-loop sunrise graph with arbitrary non-zero masses in two space-time dimensions. The analytical result is obtained by solving a second-order differential equation. The solution involves elliptic integrals and in particular the solutions of the corresponding homogeneous differential equation are given by periods of an elliptic curve.
On the thermoelectric transport properties of graphyne by the first-principles method
Authors: Wang Xiao-Ming , Mo Dong-Chuan , Lu Shu-Shen
Published: May 2013

Graphyne, another two-dimensional carbon allotrope, has received increased attentions in recent years. By using the first-principles density functional calculations combined with the non-equilibrium Green's function formalism, we investigated the electronic, thermal, and thermoelectric transport properties of graphyne systematically and comparatively. It is found that the phonon thermal conductance of graphyne is greatly reduced compared to that of graphene in most temperature regions while larger than that of graphene at low temperatures, which is attributed to the different bond strengths and phonon spectra of graphyne and graphene. Due to the semiconductor property of graphyne, the thermoelectric power (TEP) is found to be one magnitude larger than that of graphene. Besides, distinct peak value regions of TEP in the contour of chemical potential and temperature are displayed for graphyne and graphene. Finally, the thermoelectric figure of merit (ZT) of graphyne is found to be much larger than that of graphene as a result of large TEP and greatly reduced thermal conductance in graphyne, which indicates preferred thermoelectric applications for graphyne.
Experimental realization of a variable index transmission line metamaterial as an acoustic leaky-wave antenna
Authors: Naify Christina J. , Layman Christopher N. , Martin Theodore P. , Nicholas Michael , Calvo David C. , Orris Gregory J.
Published: May 2013

Development and experimental realization of an acoustic leaky wave antenna are presented. The antenna uses a one-dimensional composite right/left hand transmission line approach to tune radiation angle continually from backfire-to-endfire, including broadside, as a function of input frequency. An array of acoustically loaded membranes and open channels form a structure with negative, zero, or positive refractive index, depending on excitation frequency. The fast-wave radiation band of the antenna is determined using acoustic circuit analysis. Based on the designs specified by circuit and finite element analysis, an acoustic leaky wave antenna was fabricated, and the radiation direction measured at discrete frequencies.
Effect of growth oxygen pressure on anisotropic-strain-induced phase separation in epitaxial La0.67Ca0.33MnO3/NdGaO3(001) films
Authors: Zhi Bowen , Gao Guanyin , Huang Zhen , Wang Lingfei , Tan Xuelian , Chen Pingfan , Wu Wenbin
Published: May 2013

The effect of deposition oxygen pressure (PO) on phase separation (PS) induced in epitaxial La0.67Ca0.33MnO3/NdGaO3(001) films was investigated. Fully oxygenated films grown at high PO are anisotropically strained. They exhibit PS over a wide temperature range, because of the large orthorhombicity of NdGaO3 substrates. The paramagnetic insulator-to-ferromagnetic metal (FM) and FM-to-antiferromagnetic insulator (AFI) transitions gradually shift to lower temperatures with decreasing PO. The AFI state is initially weakened (PO ≥ 30 Pa), but then becomes more robust against the magnetic field (PO < 30 Pa). The out-of-plane film lattice parameter increases with decreasing PO. For films grown at PO ≥ 30 Pa, the slight oxygen deficiency may enlarge the lattice unit cell, reduce the anisotropic strain, and suppress the AFI state. Films deposited at PO < 30 Pa instead experience an average compressive strain. The enhanced compressive strain and structural defects in the films may lead to the robust AFI state. These results aid our understanding of PS in manganite films.
Anisotropic optical and thermoelectric properties of In4Se3 and In4Te3
Authors: Li Xingfu , Xu Bin , Yu Gongqi , Xue Li , Yi Lin
Published: May 2013

The anisotropic optical and thermoelectric properties of In4Se3 and In4Te3 are studied by the first-principles calculation using the full-potential linearized augmented plane-wave method and the semiclassical Boltzmann theory. The optical properties show highly anisotropic in the energy range between 0.0 and 12.0 eV for In4Se3 and between 0.0 and 10.0 eV for In4Te3 while it is isotropic in the higher energy range for In4Se3. In contrast to S, the anisotropies of the electrical conductivities and power factors are great affected by the change of the temperature. Their anisotropies become larger along three directions with the growth of the temperature. S2σ/τ along the y direction is much higher than that along the x and z directions for In4Se3, which shows that the thermoelectric thin films with excellent performance can be obtained along the (010) surface. By studying the anisotropy of transport properties, we find that the transport properties of In4Se3 are better than that of In4Te3, which mainly comes from the small band gap of In4Se3. The anisotropy of S2σ/τ for In4Se3 is larger than that for In4Te3, and the anisotropy of S2σ/τ is mainly due to the anisotropy of σ/τ.
Intermittency in Hall-magnetohydrodynamics with a strong guide field
Authors: Rodriguez Imazio P. , Martin L. N. , Dmitruk P. , Mininni P. D.
Published: May 2013

We present a detailed study of intermittency in the velocity and magnetic field fluctuations of compressible Hall-magnetohydrodynamic turbulence with an external guide field. To solve the equations numerically, a reduced model valid when a strong guide field is present is used. Different values for the ion skin depth are considered in the simulations. The resulting data are analyzed computing field increments in several directions perpendicular to the guide field, and building structure functions and probability density functions. In the magnetohydrodynamic limit, we recover the usual results with the magnetic field being more intermittent than the velocity field. In the presence of the Hall effect, field fluctuations at scales smaller than the ion skin depth show a substantial decrease in the level of intermittency, with close to monofractal scaling.
Cu-substitution effect on thermoelectric properties of the TiNi-based shape memory alloys
Authors: Ramachandran B. , Tang R. C. , Chang P. C. , Kuo Y. K. , Chien C. , Wu S. K.
Published: May 2013

We have studied the effects of Cu substitution on thermoelectric properties of Ti50Ni50-xCux (0 ≤ x ≤ 30 at. %) shape memory alloys by means of electrical resistivity (ρ), Seebeck coefficient (S), and thermal conductivity (κ) measurements. From the electrical resistivity and Seebeck coefficient studies, it is found that the Cu substituted TiNi alloys show a metallic nature in the entire temperature range. However, thermal hysteresis behavior was observed in all the TiNi-based alloys near martensitic transition, which confirms the first order phase transition. Transformation starting temperature of B19′ martensite (Ms) is found to be decreased with increase in Cu substitution (x > 5), whereas that of B19 martensite (M′s) increased gradually with Cu content, and the thermal hysteresis behavior becomes weaker upon substitution of Cu. It is also found that the separation between B19 and B19′ phases in the 7.5% Cu doped TiNi alloy is clearly evident in the Seebeck coefficient measurement, which is not seen in the resistivity data. Finally, analysis of thermal conductivity reveals that the anomalous feature in κ at the B19 ↔ B19′ transformation for 7.5, 10, and 15% Cu-substituted TiNi alloys which can be mainly attributed to the electronic contribution, while a large anomalous peak observed at the B19 → B2 transformation in the warming process is due to change in the lattice thermal conductivity. The relative change in thermal conductivity (Δκ/κ) near martensitic transformation is found to be increased with increase in Cu content, reaches a giant value of 200% for 10% Cu-substituted TiNi alloy and then starts to decrease with further Cu substitution.
Characteristics of terahertz pulses from antireflective GaAs surfaces with nanopillars
Authors: Kang Chul , Woo Leem Jung , Wook Lee Joong , Su Yu Jae , Kee Chul-Sik
Published: May 2013

We investigated the characteristics of terahertz pulses generated from antireflective GaAs surfaces with nanopillars under femtosecond laser excitation. Although the antireflective nanostructures contribute to the enhancement of free photocarrier excitation in GaAs, they could reduce the transient photocurrent density and advance the start time of the photocurrent decay. Thus, the relative amplitudes of the high-frequency spectral components of terahertz pulses increased, whereas the energies of the pulses decreased. However, we showed that thinly distributed nanopillar structures could generate a short terahertz pulse without a reduction in the pulse energy.
Sub-wavelength ultrasonic therapy using a spherical cavity transducer with open ends
Authors: Li Faqi , Wang Hua , Zeng Deping , Fan Tingbo , Geng Hao , Tu Juan , Guo Xiasheng , Gong Xiaobo , Zhao Chunliang , Wang Zhilong , Zhang Dong , Wang Zhibiao
Published: May 2013

High intensity focused ultrasound (HIFU) focusing precision is limited by conventional focusing ultrasound methods. The aim of this study is to develop an ultrasonic focusing modality by using a spherical cavity transducer with open ends. Experimental measurements and numerical simulations were performed to study the acoustic field and the induced tissue lesion using this transducer. The results demonstrate that the focusing zone is smaller while the focusing gain of sound pressure is higher (about 3 times) than the conventional concave focusing method. The results demonstrate great clinical potentials of enhancing the precision of HIFU therapy to the sub-wavelength level.
Electronically tunable aperiodic distributed feedback terahertz lasers
Authors: Marshall O. P. , Chakraborty S. , Khairuzzaman Md. , Folland T. , Gholinia A. , Beere H. E. , Ritchie D. A.
Published: May 2013

Focussed ion beam milling can be used to introduce aperiodic distributed feedback (ADFB) gratings into fully packaged, operational terahertz (THZ) quantum cascade lasers to achieve electronically controlled, discretely tunable laser emission. These aperiodic gratings—designed using computer-generated hologram techniques—consist of multiple slits in the surface plasmon waveguide, distributed along the length of the laser cavity. Tuning behaviour and output power in ADFB lasers operating around 2.9 THz are investigated with a variety of slit dimensions and grating scales. Mode selectivity and grating losses are found to be strongly dependent on milling depth into the upper waveguide layers, dramatically increasing as the metallic layers are penetrated, then rising more slowly with deeper milling into the laser active region. Grating scale and placement along the laser cavity length are also shown to influence mode selection.
Improving light-emitting electrochemical cells with ionic additives
Authors: Shen Yulong , Kuddes Daniel D. , Naquin Clint A. , Hesterberg Travis W. , Kusmierz Caroline , Holliday Bradley J. , Slinker Jason D.
Published: May 2013

Light-emitting electrochemical cells with ionic transition metal complexes (iTMCs) comprising the active layer have great potential for lighting applications, but to date high luminance and fast turn on times have been challenging to attain without significant loss of lifetime. Here, we demonstrate iridium iTMC devices with high luminances of 3000–5000 cd/m2, reduced turn on times, and long lifetimes through incorporation of ionic additives. Furthermore, we show additional reduction of turn on time to seconds through heat processing. We rationalize these results as the enhancement of carrier injection through improved double-layer formation at the electrodes.
A nonlinear analysis of the transport Barkhausen-like noise measured in (Bi,Pb)2Sr2Ca2Cu3O10+δ superconductors
Authors: García-Fornaris I. , Millán H. , Jardim R. F. , Govea-Alcaide E.
Published: May 2013

We investigated the transport Barkhausen-like noise (TBN) by using nonlinear time series analysis. TBN signals were measured in (Bi,Pb)2Sr2Ca2Cu3O10+δ ceramic samples subjected to different uniaxial compacting pressures (UCP). These samples display similar intragranular properties but different intergranular features. We found positive Lyapunov exponents in all samples, λm≥0.062, indicating the nonlinear dynamics of the experimental TBN signals. It was also observed higher values of the embedding dimension, m>9, and the Kaplan-Yorke dimension, DKY>2.9. Between samples, the behavior of λm and DKY with increasing excitation current is quite different. Such a behavior is explained in terms of changes in the microstructure associated with the UCP. In addition, determinism tests indicated that the TBN masked determinist components, as inferred by |k→| values larger than 0.70 in most of the cases. Evidence on the existence of empirical attractors by reconstructing the phase spaces has been also found. All obtained results are useful indicators of the interplay between the uniaxial compacting pressure, differences in the microstructure of the samples, and the TBN signal dynamics.
Robust sensing methodology for detecting change with bistable circuitry dynamics tailoring
Authors: Harne R. L. , Wang K. W.
Published: May 2013

In contrast to monitoring natural frequency shift, bifurcation-based sensing techniques utilize dramatic switches in response amplitude to detect structural change. We demonstrate a highly sensitive bifurcation-based sensing method requiring only the monitored structure, a transduction mechanism, and bistable electric circuitry. The system configuration is broadly applicable from, e.g., microscale mass sensing to structural health monitoring. In contrast to single bifurcation events of past techniques, the present methodology introduces new bifurcations that may be utilized sequentially for monitoring numerous thresholds of structural parameter change. We show that bifurcation-based sensing potential and versatility is greatly advanced.
Scaling and saturation of high-power terahertz radiation generation in two-color laser filamentation
Authors: Oh T. I. , You Y. S. , Jhajj N. , Rosenthal E. W. , Milchberg H. M. , Kim K. Y.
Published: May 2013

Broadband terahertz generation via two-color femtosecond laser filamentation is studied with laser input energies up to 60 mJ. In the small f-number focusing regime, the output THz energy strongly saturates, which is attributed to ionization-induced laser defocusing in filamentation. This saturation effect can be minimized by elongating the plasma filament with weak focusing. A conversion efficiency of >10−4 is achieved in elongated filamentation.
Subversive Patterning: The Surficial Qualities of Camouflage
Authors: Forsyth Isla
Published: May 2013

During the mid-20th century there was new utility in combining scientific, artistic, and military knowledge for the development of effective military camouflage. When WWII was declared the military began recruiting seemingly disparate specialists, such as surrealist artists, a zoologist, and a magician to train in concealment: to become camoufleurs. Across diverse environments and battlefields these camoufleurs plied their trade of secrecy, in the process militarising landscapes and their knowledges. This paper will explore how camouflage was developed for different interrelated surfaces during war, whether for the sea in WWI, the earth, or in response to aerial warfare. In particular this paper will explore the surface of sand in the Desert War in WWII, which demanded a new relationship between modern militarism and knowledge of the earth's surface, in order to develop effective camouflage. In turn, it will reveal that camouflage was a defining factor influencing the geographies of the desert as a theatre of war, transforming it into a bewildering topography requiring, as one soldier put it, ‘mental guts’.
Crossing Surfaces in Search of the Holy: Landscape and Liminality in Contemporary Christian Pilgrimage
Authors: Maddrell Avril , della Dora Veronica
Published: May 2013

This paper examines the role of surfaces in pilgrimage practices and experiences in two denominational and cultural contexts and landscape settings for Christian pilgrimage: a week of Ecumenical pilgrimage walks in the Isle of Man and Orthodox pilgrimage to the monasteries of Meteora in Greece. Surfaces are examined as dynamic textured platforms for journeying and stages for the performance of ritual; as part of visual aesthetic and multisensory embodied experiences; as hermeneutical texts; as perceived liminal thresholds through which the divine might be experienced; and as tangible material fragments encapsulating and facilitating the ‘taking home’ of the pilgrim experience. Surfaces are found to be significant for pilgrims in a variety of shared ways, but also ways which are inflected by different theological and cultural contexts. Through its analysis of faith adherents and practices, this study offers (i) a spiritually informed perspective on both perceptions and experiences of surfaces, and (ii) understanding of faith-inflected mobilities and ‘more-than-representational’ meanings and practices.
A Decade of Learning about Publics, Participation, and Climate Change: Institutionalising Reflexivity?
Authors: Pallett Helen , Chilvers Jason
Published: May 2013

Building on previous studies of participatory learning amongst individuals within discrete participation processes, the authors examine organisationally situated processes of learning related to public participation in science and environmental governance. Qualitative analysis of documents and semistructured interviews is used to explore frames of participation, publics, and the issue of climate change, both transforming and stable. This illuminates trends of learning in the context of the organisational network around the UK Government-funded body Sciencewise and related organisations, from 2000 to 2010. It is argued that formal organisational learning mechanisms foster instrumental learning, precluding reflective and relational learning which could potentially transform organisational assumptions and routines around participation. However, informal social networks have promoted transformative social learning and reflexivity at particular moments during the decade.