pinecone/core-2020-05-10-deduplication huggingface dataset:
Query performance prediction for information retrieval based on covering topic score

We present a statistical method called Covering Topic Score (CTS) to predict query performance for information\ud
retrieval. Estimation is based on how well the topic of a user's query is covered by documents retrieved from a certain retrieval system. Our approach is conceptually simple and intuitive, and can be easily extended to incorporate features beyond bag-of-words such as phrases and proximity of terms. Experiments demonstrate that CTS significantly correlates with query performance in a variety of TREC test collections, and in particular CTS gains more prediction power benefiting from features of phrases and proximity of terms. We compare CTS with previous state-of-the-art methods for query performance prediction including clarity score and robustness score. Our experimental results show that CTS consistently performs better than, or at least as well as, these other methods. In addition to its high effectiveness, CTS is also shown to have very low computational complexity, meaning that it can be practical for real applications
Optimization of tensile strength of ferritic / austenitic laser welded components

Ferritic/Austenitic (F/A) joints are a popular dissimilar metals combination used in many applications. F/A joints are usually produced using conventional processes. Laser beam welding (LBW) has recently been successfully used for the production of F/A joints with suitable mechanical properties. In this study, a statistical design of experiment (DOE) was used to optimise selected laser beam welding parameters (laser power, welding speed, and focus length). The Taguchi approach was used for the selected factors, each having five levels (L-25; 5*3). Joint strength was determined using the notched tension strength (NTS) method. The results were analysed using analyses of variance (ANOVA) and the signal-to-noise ratios (S/N) ratio for the optimal parameters, and then compared with the base material. The experimental results indicate that the F/A laser welded joints are improved effectively by optimizing the input parameters using the Taguchi approach
Level Set Segmentation with Shape and Appearance Models Using Affine Moment Descriptors

We propose a level set based variational approach that incorporates shape priors into edge-based and region-based models. The evolution of the active contour depends on local and global information. It has been implemented using an efficient narrow band technique. For each boundary pixel we calculate its dynamic according to its gray level, the neighborhood and geometric properties established by training shapes. We also propose a criterion for shape aligning based on affine transformation using an image normalization procedure. Finally, we illustrate the benefits of the our approach on the liver segmentation from CT images
Geochemistry and risk assessment of street dust in Luanda, Angola, a tropical urban environment

A total of 92 samples of street dust were collected in Luanda, Angola, were sieved below 100 μm, and analysed by ICP-MS for 35 elements after an aqua-regia digestion. The concentration and spatial heterogeneity of trace elements in the street dust of Luanda are generally lower than in most industrialized cities in the Northern hemisphere. These observations reveal a predominantly “natural” origin for the street dust in Luanda, which is also manifested in that some geochemical processes that occur in natural soils are preserved in street dust: the separation of uranium from thorium, and the retention of the former by carbonate materials, or the high correlation between arsenic and vanadium due to their common mode of adsorption on solid particles in the form of oxyanions. The only distinct anthropogenic fingerprint in the composition of Luanda's street dust is the association Pb–Cd–Sb–Cu (and to a lesser extent, Ba–Cr–Zn). The use of risk assessment strategies has proved helpful in identifying the routes of exposure to street dust and the trace elements therein of most concern in terms of potential adverse health effects. In Luanda the highest levels of risk seem to be associated (a) with the presence of As and Pb in the street dust and (b) with the route of ingestion of dust particles, for all the elements included in the study except Hg, for which inhalation of vapours presents a slightly higher risk than ingestion. However, given the large uncertainties associated with the estimates of toxicity values and exposure factors, and the absence of site-specific biometric factors, these results should be regarded as preliminary and further research should be undertaken before any definite conclusions regarding potential health effects are drawn
Modal contribution and state space order selection in operational modal analysis

The estimation of modal parameters of a structure from ambient measurements has attracted the attention of many researchers in the last years. The procedure is now well established and the use of state space models, stochastic system identification methods and stabilization diagrams allows to identify the modes of the structure. In this paper the contribution of each identified mode to the measured vibration is discussed. This modal contribution is computed using the Kalman filter and it is an indicator of the importance of the modes. Also the variation of the modal contribution with the order of the model is studied. This analysis suggests selecting the order for the state space model as the order that includes the modes with higher contribution. The order obtained using this method is compared to those obtained using other well known methods, like Akaike criteria for time series or the singular values of the weighted projection matrix in the Stochastic Subspace Identification method. Finally, both simulated and measured vibration data are used to show the practicability of the derived technique. Finally, it is important to remark that the method can be used with any identification method working in the state space model
Poly(neutral red): Electrosynthesis, Characterization, and Application as a Redox Mediator

The synthesis by electropolymerization, the characterization, and applications of poly(neutral red) (PNR), including as a redox mediator, are reviewed. PNR's high electrical conductivity and its redox characteristics have led to special applications of the polymer, and it has been used for the development of electrochemical and optical sensors. Moreover, the attractive properties of PNR allow it to be applied in the development of electrochemical biosensors. Future perspectives are indicated.http://dx.doi.org/10.1002/elan.20080421
Causality assessment of adverse drug reactions: comparison of the results obtained from published decisional algorithms and from the evaluations of an expert panel

To compare the results of causality assessments of reported adverse drug reactions (ADR's) obtained from decisional algorithms with those obtained from an expert panel using the WHO global introspection method (GI) and to further evaluate the influence of confounding variables on algorithms ability in assessing causality.Two hundred sequentially reported ADR's were included in this study. An independent researcher used algorithms, while an expert panel assessed the same reports using the GI, both aimed at evaluating causality. Reports were divided into three groups according to the presence, absence or lack of information on confounding variables.For the total sample, observed agreements between decisional algorithms compared with GI varied from 21% to 56%, average of 47%. When confounding variables were taken into account, agreements varied between 41% and 69%, average of 58%; 8% and 65%, average of 46% and 15% and 53%, average of 42% accordingly to the absence, lack of information or presence of confounding variables, respectively. The extend of reproducibility beyond chance was low for the total sample (average Kappa = 0.26) and within the groups considered.The overall observed agreement between algorithm and GI was moderate although poorly different from chance, confounding variables being a shortcoming of algorithms ability in assessing causality. Copyright © 2005 John Wiley & Sons, Ltd.http://dx.doi.org/10.1002/pds.113
Metabolic and Genetic Diversity of Mesophilic and Thermophilic Bacteria Isolated from Composted Municipal Sludge on Poly-e-caprolactones

Thirty mesophilic and thermophilic bacteria were isolated from thermobiotically digested sewage sludge in culture medium supplemented with poly-e-caprolactone (PCL). The ability of each purified isolate to degrade PCL and to produce polymer-degrading extracellular enzymes was assessed. Isolates were characterized based on random amplified polymorphic DNA (RAPD), 16S rDNA sequence-based phylogenetic affiliation and carbohydrate-based nutritional versatility. Mesophilic isolates with ability to degrade PCL were attributed to the genera Acinetobacter, Burkholderia, Pseudomonas, and Staphylococcus. Thermophilic isolates were members of the genus Bacillus. Despite the restricted phylogenetic and genotypic diversity observed for thermophiles, their metabolic versatility and wide range of growth temperatures suggest an important activity of these organisms during the whole composting process.http://dx.doi.org/10.1007/s00284-004-4353-
Assessing the suitability and safety of a well-known bud-galling wasp, Trichilogaster acaciaelongifoliae, for biological control of Acacia longifolia in Portugal

Acacia longifolia is a widespread invasive plant species in Portugal. In South Africa, it is controlled by a bud-galling wasp, Trichilogaster acaciaelongifoliae, which could also be used in Portugal. Biological control of invasive alien plants has received little consideration anywhere in Europe and has never been attempted in Portugal. The lack of a suitably-large quarantine facility necessitated the use of a novel approach to test non-target species in Portugal. Mature T. acaciaelongifoliae galls were shipped to Portugal from South Africa to obtain adult female wasps which were confined in Petri dishes each with a bud-bearing branch of one of 40 non-target plant species. The time spent by the wasps exploring and probing the buds was measured after which buds were dissected to detect any egg deposition. The results showed that T. acaciaelongifoliae did not respond to the buds of most (23) species. The females spent time on the buds of the other 17 species but only laid eggs in three species besides A. longifolia. Oviposition on Acacia melanoxylon was expected but was not anticipated on Vitis vinifera, vines, (where eggs were deposited externally in the pubescent coat of the buds) or on Cytisus striatus, broom, (where eggs were inserted into the buds as they are on A. longifolia). Subsequent trials on potted plants showed that galls only developed on A. longifolia. Field surveys in South Africa and Australia showed that galls never occur on either vines or broom. The implications of these findings for the use of T. acaciaelongifoliae for biological control of A. longifolia in Portugal are considered in relation to the wealth of experience and knowledge about the specificity of the wasp and the reliability of conducting host-specificity tests under confined conditions of cages
General Three-Point Functions in 4D CFT

We classify and compute, by means of the six-dimensional embedding formalism in twistor space, all possible three-point functions in four dimensional conformal field theories involving bosonic or fermionic operators in irreducible representations of the Lorentz group. We show how to impose in this formalism constraints due to conservation of bosonic or fermionic currents. The number of independent tensor structures appearing in any three-point function is obtained by a simple counting. Using the Operator Product Expansion (OPE), we can then determine the number of structures appearing in 4-point functions with arbitrary operators. This procedure is independent of the way we take the OPE between pairs of operators, namely it is consistent with crossing symmetry, as it should be. An analytic formula for the number of tensor structures for three-point correlators with two symmetric and an arbitrary bosonic (non-conserved) operators is found, which in turn allows to analytically determine the number of structures in 4-point functions of symmetric traceless tensors
Multi-level selectional stalemate in a simple artificial chemistry

We describe a simple artificial chemistry which abstracts a small number of key features from the origin of life "replicator world" hypotheses. We report how this can already give rise to moderately complex and counter-intuitive evolutionary phenomena, including macro- evolutionary deterioration in replication fidelity (which corresponds to intrinsic replicator fitness in this model). We briefly describe the extension of this model to incorporate a higher, protocell, level of selection.  We\ud
show that the interaction between the two levels of selection then serves to control parasitic exploitation at the molecular level, while still significantly constraining accessible evolutionary trajectories at the protocell level. We conclude with a brief discussion of the implications for further work
Plasma sprayed hydroxyapatite coatings: understanding process relationships using design of experiment analysis

The biocompatibility and osteoconductivity of hydroxyapatite (HA) coatings have led to their use in a wide range of applications in dentistry and orthopaedics. One such application is for the uncemented fixation of implants, where coatings are commonly applied to titanium implants using a plasma thermal spraying process. The spraying process is affected by a large number of parameters leading to highly complex process – property – structure relationships. In a step forward from one-at-a-time analyses, this study used Design of Experiment (DOE) methodology to investigate the simultaneous effects of key plasma spray process parameters on hydroxyapatite coatings for biomedical applications. The effects of five plasma spray process parameters (current, gas flow rate, powder feed rate, spray distance and carrier gas flow rate) on the roughness, crystallinity and purity of hydroxyapatite coatings was determined using a fractional factorial design. The results of this study enabled identification of consistent and competing influences within the process and the identification of some first order interactions. In particular, the diffuse particle size of the HA feedstock powder was found to influence the responses observed within the parameter range investigated. The roughness of HA coatings was found to relate to the particle velocity and the degree of particle melting occurring, withhigher coating roughness resulting when current was high, gas flow rate was low and powder feed rate was high. Highest coating crystallinity resulted at high current, low spray distance and low carrier gas flow rate. Under these conditions deposition of larger HA particles resulted leading to higher amounts of bulk crystalline material and the low spray distance increased the substrate temperature allowing amorphous material to recrystallise. Coating purity relates directly to thermal decomposition of the particles within the plasma jet with a high purity coating resulting at low particle temperatures i.e at the lower ranges of powder feed rate, spray distance and carrier gas flow rate. This study thus brings greater clarity on the effects of plasma spray process parameters on the properties of resultant hydroxyapatite coatings
Increasing gap in human height between rich and poor countries associated to their different intakes of N and P

We analyzed mean height of men born in the 1960s, 1970s and 1980s in 80 countries. Both height and the change in height during the last decades were correlated with N and P intake, as well as the N:P intake ratio. Rich countries had higher per capita N and P intake than poor countries (on average 19.5 ± 0.3 versus 9.66 ± 0.18 kg N y-1 and 2.17 ± 0.04 versus 1.35 ± 0.02 kg P y-1), and also larger increases in per capita N intake (12.1 ± 2.0% vs. 7.0 ± 2.1%) and P intake (7.6 ± 1.0% vs 6.01 ± 0.7%), during the period 1961-2009. The increasing gap in height trends between rich and poor countries is associated with an increasing gap in nutrition, so a more varied diet with higher N, P, and N:P intake is a key factor to improve food intake quality in poor countries and thus shorten the gap with rich countries. More N and P are needed with the consequent requirements for a better management of the socioeconomic and environmental associated problems
Representations of the occupation number matrix on the LDA/GGA+U method

An analysis of the general represntation of the occupation number matrix on density functional theory in conjunction with the generalized Hubbard model is presented. A central fact that will be addressed is that the total charge density cannot be broken down into simple atomic contributions. This fact means that the orbital occupations are not well defined. Different representations of the occupation number matrix, both that it conserves and that it does not conserve the number of electrons of the system, are compared. A localized basis set is used, which is suitable for large-scale electronic structure calculations based on the density functional theory. This methodology is applied to typical and well-analysed transition-metal oxide bulk systems and to Cr-doped zinc chalogenides and chalcopyrites. The bandgap, magnetic moment and detailed electronic structures are investigated and discussed with the different choices of the occupation number matrix. The results are in good agreement with previous theoretical and experimental studies
Weakly-nonlinear analysis of the Rayleigh–Taylor instability in a vertically vibrated, large aspect ratio container

We consider a horizontal liquid layer supported by air in a wide (as compared to depth) container, which is vertically vibrated with an appropriately large frequency, intending to counterbalance the Rayleigh-Taylor instability of the fíat, rigid-body vibrating state. We apply a long-wave, weakly-nonlinear analysis that yields a generalized Cahn-Hilliard equation for the evolution of the fluid interface, with appropriate boundary conditions obtained by a boundary layer analysis. This equation shows that the stabilizing effect of vibration is like that of surface tensión, and is used to analyze the linear stability of the fíat state, and the local bifurcation at the instability threshold
A new class of symbolic abstract neural nets

Starting from the way the inter-cellular communication takes place by means of protein channels and also from the standard knowledge about neuron functioning, we propose a computing model called a tissue P system, which processes symbols in a multiset rewriting sense, in a net of cells similar to a neural net. Each cell has a finite state memory, processes multisets of symbol-impulses, and can send impulses (?excitations?) to the neighboring cells. Such cell nets are shown to be rather powerful: they can simulate a Turing machine even when using a small number of cells, each of them having a small number of states. Moreover, in the case when each cell works in the maximal manner and it can excite all the cells to which it can send impulses, then one can easily solve the Hamiltonian Path Problem in linear time. A new characterization of the Parikh images of ET0L languages are also obtained in this framework
Chinese energy and climate policies after Durban: save the Kyoto Protocol

Nowadays, one of the urgent issues regarding global climate change is to discuss the future of the second period of the Kyoto Protocol. However, the divergence of views and opinions among parties in the last Conference of the Parties of the United Nations Framework Convention on Climate Change, held in Durban in December 2011, is still large. One of the bones of contention is whether the emerging developing countries, like China, should make commitments and legally bind themselves to a Green House Gas (GHG) reduction target in near future. As the largest GHG emitting country, China and its energy and climate policies will play an important role in global climate change and will also significantly influence the other countries? policies and the global climate negotiation. In this paper, we review the current differences among parties in the Durban Conference, and we analyze the recent situation, barriers, and future policies in China. Finally we highlight the impact and potential effect of Clean Development Mechanisms in avoiding China?s barriers regarding climate change. Results show that China is making a great effort to mitigate climate change by establishing and reforming its energy and climate policies in order to achieve a low-carbon development. At the same time, more innovation and international collaboration is needed in China to achieve this goal
Synthetic strategy of porous ZnO and CdS nanostructures doped ferroelectric liquid crystal and its optical behavior

A simple and scalable chemical approach has been proposed for the generation of 1-dimensional nanostructures of two most important inorganic materials such as zinc oxide and cadmium sulfide. By controlling the growth habit of the nanostructures with manipulated reaction conditions, the diameter and uniformity of the nanowires/nanorods were tailored. We studied extensively optical behavior and structural growth of CdS NWs and ZnO NRs doped ferroelectric liquid crystal Felix-017/100. Due to doping band gap has been changed and several blue shifts occurred in photoluminescence spectra because of nanoconfinement effect and mobility of charges
Hybrid dome with total internal reflector as a secondary optical element for CPV

Secondary optical elements (SOEs) are used in Concentrator Photovoltaic (CPV) modules to allow the concentration ratio to exceed those typically achievable by Fresnel lenses, reducing cell costs, without sacrificing tolerance to tracking errors. One option is a “dome” SOE: a simple, single surface refractive optic that images the primary lens onto the cell while immersing it. In this article, we explore the limits of this type of SOE and propose an evolved version, which we dub the Hybrid Dome Reflector (HDR), which offers advantages especially for high concentration modules with large cells, where reflective secondaries do not offer sufficient acceptance angle, but other dielectric secondaries, such as the Dielectric Totally Internally Reflecting Concentrator DTIRC, may be too large for\ud
economical manufacture. We discuss aspects of HDR design and share selected ray-tracing simulations and experimental results. We show that the new HDR design improves acceptance angle and tolerances to manufacturing error and lens temperature as compared to a reflective SOE built while offering similar efficiencies
Room temperature photo-response of titanium supersaturated silicon at energies over the bandgap

Silicon samples were implanted with high Ti doses and subsequently processed with the pulsed-laser melting technique. The electronic transport properties in the 15-300 K range and the room temperature spectral photoresponse at energies over the bandgap were measured. Samples with Ti concentration below the insulator-metal (I-M) transition limit showed a progressive reduction of the carrier lifetime in the implanted layer as Ti dose is increased. However, when the Ti concentration exceeded this limit, an extraordinary recovery of the photoresponse was measured. This result supports the theory of intermediate band materials and is of utmost relevance for photovoltaic cells and Si-based detectors