bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estimating epistemic and aleatory uncertainties during hydrologic modeling: An information theoretic approach
Authors: Gong Wei , Gupta Hoshin V. , Yang Dawen , Sricharan Kumar , Hero Alfred O. 
Published: March 2013

Key Points
Methods are provided to quantify information and uncertainty in data
Best achievable model performance for a given data set is estimated
Model adequacy is characterized in terms of Aleatory and Epistemic Uncertainties
Sensitivity analysis of a time-delayed thermo-acoustic system via an adjoint-based approach
Authors: Magri Luca , Juniper Matthew P. 
Published: March 2013

AbstractWe apply adjoint-based sensitivity analysis to a time-delayed thermo-acoustic system: a Rijke tube containing a hot wire. We calculate how the growth rate and frequency of small oscillations about a base state are affected either by a generic passive control element in the system (the structural sensitivity analysis) or by a generic change to its base state (the base-state sensitivity analysis). We illustrate the structural sensitivity by calculating the effect of a second hot wire with a small heat-release parameter. In a single calculation, this shows how the second hot wire changes the growth rate and frequency of the small oscillations, as a function of its position in the tube. We then examine the components of the structural sensitivity in order to determine the passive control mechanism that has the strongest influence on the growth rate. We find that a force applied to the acoustic momentum equation in the opposite direction to the instantaneous velocity is the most stabilizing feedback mechanism. We also find that its effect is maximized when it is placed at the downstream end of the tube. This feedback mechanism could be supplied, for example, by an adiabatic mesh. We illustrate the base-state sensitivity by calculating the effects of small variations in the damping factor, the heat-release time-delay coefficient, the heat-release parameter, and the hot-wire location. The successful application of sensitivity analysis to thermo-acoustics opens up new possibilities for the passive control of thermo-acoustic oscillations by providing gradient information that can be combined with constrained optimization algorithms in order to reduce linear growth rates.
Interplay among unstable modes in films over permeable walls
Authors: Camporeale C. , Mantelli E. , Manes C. 
Published: March 2013

AbstractThe stability of open-channel flows (or film flows) has been extensively investigated for the case of impermeable smooth walls. In contrast, despite its relevance in many geophysical and industrial flows, the case that considers a permeable rather than an impermeable wall is almost unexplored. In the present work, a linear stability analysis of a film falling over a permeable and inclined wall is developed and discussed. The focus is on the mutual interaction between three modes of instability, namely, the well-known free-surface and hydrodynamic (i.e. shear) modes, which are commonly observed in open-channel flows over impermeable walls, plus a new one associated with the flow within the permeable wall (i.e. the porous mode). The flow in this porous region is modelled by the volume-averaged Navier–Stokes equations and, at the wall interface, the surface and subsurface flow are coupled through a stress-jump condition, which allows one to obtain a continuous velocity profile throughout the whole flow domain. The generalized eigenvalue problem is then solved via a novel spectral Galerkin method, and the whole spectrum of eigenvalues is presented and physically interpreted. The results show that, in order to perform an analysis with a full coupling between surface and subsurface flow, the convective terms in the volume-averaged equations have to be retained. In previous studies, this aspect has never been considered. For each kind of instability, the critical Reynolds number (${\mathit{Re}}_{c} $) is reported for a wide range of bed slopes ($\theta $) and permeabilities ($\sigma $). The results show that the free-surface mode follows the behaviour that was theoretically predicted by Benjamin and Yih for impermeable walls and is independent of wall permeability. In contrast, the shear mode shows a high dependence on $\sigma $: at $\sigma = 0$ the behaviour of ${\mathit{Re}}_{c} (\theta )$ recovers the well-known non-monotonic behaviour of the impermeable-wall case, with a minimum at $\theta \sim 0. 05\textdegree $. However, with an increase in wall permeability, ${\mathit{Re}}_{c} $ gradually decreases and eventually recovers a monotonic decreasing behaviour. At high values of $\sigma $, the porous mode of instability also occurs. A physical interpretation of the results is presented on the basis of the interplay between the free-surface-induced perturbation of pressure, the increment of straining due to shear with the increase in slope, and the shear stress condition at the free surface. Finally, the paper investigates the extent to which Squire’s theorem is applicable to the problem presented herein.
Nonlinear disturbance growth during sedimentation in dilute fibre suspensions
Authors: Zhang Feng , Dahlkild Anders A. , Lundell Fredrik 
Published: March 2013

AbstractDisturbances in a dilute fibre suspension are studied with an Eulerian approach. Based on a linear stability analysis, it is shown that inertia and hydrodynamic diffusion damp perturbations at long wavelengths and short wavelengths, respectively, leading to a wavenumber selection. For small but finite Reynolds number of the fluid bulk motion, the most unstable wavenumber is a finite value, which increases with Reynolds number. Furthermore, the diffusion narrows the range of unstable wavenumbers. Numerical simulations of the full nonlinear evolution in time of a normal-mode perturbation show that the induced flow may either die out or saturate on a finite amplitude. The character of this long-time behaviour is dictated by the wavenumber and the presence or absence, as well as nature, of the translational and rotational diffusivities.
Generalized logarithmic law for high-order moments in turbulent boundary layers
Authors: Meneveau Charles , Marusic Ivan 
Published: March 2013

AbstractHigh-Reynolds-number data in turbulent boundary layers are analysed to examine statistical moments of streamwise velocity fluctuations ${u}^{\prime } $. Prior work has shown that the variance of ${u}^{\prime } $ exhibits logarithmic behaviour with distance to the surface, within an inertial sublayer. Here we extend these observations to even-order moments. We show that the $2p$-order moments, raised to the power $1/ p, $ also follow logarithmic behaviour according to $\langle \mathop{({u}^{\prime + } ){}^{2p} \rangle }\nolimits ^{1/ p} = {B}_{p} - {A}_{p} \ln (z/ \delta )$, where ${u}^{\prime + } $ is the velocity fluctuation normalized by the friction velocity, $\delta $ is an outer length scale and ${B}_{p} $ are non-universal constants. The slopes ${A}_{p} $ in the logarithmic region appear quite insensitive to Reynolds number, consistent with universal behaviour for wall-bounded flows. The slopes differ from predictions that assume Gaussian statistics, and instead are consistent with sub-Gaussian behaviour.
Modelling circulation, impulse and kinetic energy of starting jets with non-zero radial velocity
Authors: Krieg Michael , Mohseni Kamran 
Published: March 2013

AbstractThe evolution of starting jet circulation, impulse and kinetic energy are derived in terms of kinematics at the entrance boundary of a semi-infinite axisymmetric domain. This analysis is not limited to the case of parallel jet flows; and the effect of non-zero radial velocity is specifically identified. The pressure distribution along the entrance boundary is also derived as it is required for kinetic energy modelling. This is done without reliance on an approximated potential function (i.e. translating flat plate), making it a powerful analytical tool for any axisymmetric jet flow. The pressure model indicates that a non-zero radial velocity is required for any ‘over-pressure’ at the nozzle exit. Jet flows are created from multiple nozzle configurations to validate this model. The jet is illuminated in cross-section, and velocity and vorticity fields are determined using digital particle image velocimetry (DPIV) techniques and circulation, impulse and kinetic energy of the jet are calculated from the DPIV data. A non-zero radial velocity at the entrance boundary has a drastic effect on the final jet. Experimental data showed that a specific configuration resulting in a jet with a converging radial velocity, with a magnitude close to 40 % of the axial velocity at its maximum, attains a final circulation which is 90–100 % larger than a parallel starting jet with identical volume flux and nozzle diameter, depending on the stroke ratio. The converging jet also attains a final impulse which is 70–75 % larger than the equivalent parallel jet and a final kinetic energy 105–135 % larger.
Modeling temperature-dependent survival with small datasets: insights from tropical mountain agricultural pests
Authors: Crespo-Pérez Verónica , Dangles Olivier , Régnière Jacques , Chuine Isabelle 
Published: March 2013

AbstractMany regions are increasingly threatened by agricultural pests but suffer from a lack of data that hampers the development of adequate population dynamics models that could contribute to pest management strategies. Here, we present a new model relating pest survival to temperature and compare its performance with two published models. We were particularly interested in their ability to simulate the deleterious effect of extreme temperatures even when adjusted to datasets that did not include extreme temperature conditions. We adjusted the models to survival data of three species of potato tuber moth (PTM), some major pests in the Tropical Andes. To evaluate model performance, we considered both goodness-of-fit and robustness. The latter consisted in evaluating their ability to predict the actual altitudinal limits of the species in the Ecuadorian Andes. We found that even though our model did not always provide the best fit to data, it predicted extreme temperature mortality and altitudinal limits accurately and better than the other two models. Our study shows that the ability to accurately represent the physiological limits of species is important to provide robust predictions of invasive pests' potential distribution, particularly in places where temperatures approach lethal extremes. The value of our model lies in its ability to simulate accurate thermal tolerance curves even with small datasets, which is useful in places where adequate pest management is urgent but data are scarce.
The experience of family care-givers and migrant paid care-givers' relief of burden: a contrasted qualitative analysis
Authors: DE LA CUESTA-BENJUMEA CARMEN , ROE BRENDA 
Published: March 2013

ABSTRACTOlder people are increasingly being cared for in the community across Europe. Dependent care in Spain largely remains a private issue involving family carers and migrant women from developing countries. Qualitative research on respite care has contributed to our understanding of respite as a subjective experience. Nonetheless, how care-givers relieve the burden of care is still not fully understood. Migrant care-givers are present in family life but their need for rest remains unseen. The aim of the study presented in this paper was to contrast family care-givers and migrant care-givers' strategies for relief from their caring role. Care-givers rest by thinking, doing and being but in a different manner from that of care-giving, that is: when they are a different person.To leave the life of care-givingis the general strategy that family care-givers use to rest from their care-giving selves whileturning to one's own worlddescribes the way migrant care-givers seek to relieve the burden of care. The comparative analysis shows that both strategies have in common the necessity to disconnect from the care-giving identity and that both migrant and family care-givers employ strategies that arefalse exits to a care-giving identity: they apparently relieve the burden of care. Respite goes beyond places, times and activities; as family care itself, it requires identity.
A two dimensional lattice of knots by C2m-moves
Authors: HORIUCHI SUMIKO , OHYAMA YOSHIYUKI 
Published: March 2013

AbstractWe consider a local move on a knot diagram, where we denote the local move by λ. If two knots K1 and K2 are transformed into each other by a finite sequence of λ-moves, the λ-distance between K1 and K2 is the minimum number of times of λ-moves needed to transform K1 into K2. A λ-distance satisfies the axioms of distance. A two dimensional lattice of knots by λ-moves is the two dimensional lattice graph which satisfies the following: the vertex set consists of oriented knots and for any two vertices K1 and K2, the distance on the graph from K1 to K2 coincides with the λ-distance between K1 and K2, where the distance on the graph means the number of edges of the shortest path which connects the two knots. Local moves called Cn-moves are closely related to Vassiliev invariants. In this paper, we show that for any given knot K, there is a two dimensional lattice of knots by C2m-moves with the vertex K.
Adapting environmental conservation legislation for an enlarged European Union: experience from the Habitats Directive
Authors: EVANS DOUGLAS , DEMETER ANDRÁS , GAJDOŠ PETER , HALADA ĽUBOŠ 
Published: March 2013

SUMMARYThe European Union's (EU's) Habitats Directive includes annexes listing the habitats and species requiring protection. As new countries join the EU these lists need to be amended to remain pertinent. In 2004 and 2007, 12 countries, mostly in central Europe, joined the EU and were asked to propose native species or habitats that required protection; this formed an initial base for negotiations with the European Commission in consultation with the existing member states and with scientific support from the European Topic Centre on Biological Diversity. The 12 countries made 831 proposals, resulting in the addition of 191 species and 33 habitats, and geographical exemptions for eight species. Although the Directive provided definitions, these needed to be supplemented with additional criteria to permit assessments of the proposals. The process involved many actors at both European and national level. This illustrates the development of biodiversity governance and provides potential lessons for future activities, including the need for scientific guidance and the importance of involving all relevant actors.
ZEROS OF THE ESTERMANN ZETA FUNCTION
Authors: DUBICKAS A. , GARUNKŠTIS R. , STEUDING J. , STEUDING R. 
Published: March 2013

AbstractIn this paper we investigate the zeros of the Estermann zeta function $E(s; k/ \ell , \alpha )= { \mathop{\sum }\nolimits}_{n= 1}^{\infty } {\sigma }_{\alpha } (n) \exp (2\pi ink/ \ell ){n}^{- s} $ as a function of a complex variable $s$, where $k$ and $\ell $ are coprime integers and ${\sigma }_{\alpha } (n)= {\mathop{\sum }\nolimits}_{d\vert n} {d}^{\alpha } $ is the generalized divisor function with a fixed complex number $\alpha $. In particular, we study the question on how the zeros of $E(s; k/ \ell , \alpha )$ depend on the parameters $k/ \ell $ and $\alpha $. It turns out that for some zeros there is a continuous dependency whereas for other zeros there is not.
PROBING THE INNER REGIONS OF PROTOPLANETARY DISKS WITH CO ABSORPTION LINE SPECTROSCOPY
Authors: McJunkin Matthew , France Kevin , Burgh Eric B. , Herczeg Gregory J. , Schindhelm Rebecca N. , Brown Joanna M. , Brown Alexander 
Published: March 2013

ABSTRACT
Carbon monoxide (CO) is the most commonly used tracer of molecular gas in the inner regions of protoplanetary disks. CO can be used to constrain the excitation and structure of the circumstellar environment. Absorption line spectroscopy provides an accurate assessment of a single line of sight through the protoplanetary disk system, giving more straightforward estimates of column densities and temperatures than CO and molecular hydrogen (H2) emission line studies. We analyze new observations of ultraviolet CO absorption from the Hubble Space Telescope along the sightlines to six classical T Tauri stars. Gas velocities consistent with the stellar velocities, combined with the moderate-to-high disk inclinations, argue against the absorbing CO gas originating in a fast-moving disk wind. We conclude that the far-ultraviolet observations provide a direct measure of the disk atmosphere or possibly a slow disk wind. The CO absorption lines are reproduced by model spectra with column densities in the range N(12CO) ∼ 1016–1018 cm−2 and N(13CO) ∼ 1015–1017 cm−2, rotational temperatures T
rot(CO) ∼ 300–700 K, and Doppler b-values, b ∼ 0.5–1.5 km s−1. We use these results to constrain the line-of-sight density of the warm molecular gas (n
CO ∼ 70–4000 cm−3) and put these observations in context with protoplanetary disk models.
A study of misaligned hole‐entry worn journal bearing operating in turbulent regime
Authors: Ram Nathi , Sharma Satish 
Published: March 2013

PurposeThe purpose of this paper is to study theoretically the combined influence of journal misalignment and wear on the performance of a hole‐entry hybrid journal bearing system. The bearing is assumed to be operating in a turbulent regime.Design/methodology/approachThe modified Reynolds equation based on Constantinescu lubrication theory has been solved by using finite element method together with orifice and capillary restrictors flow equations as a constrain together with appropriate boundary conditions.FindingsIt has been observed that for a symmetric hole‐entry journal bearing configuration the value of h¯min is more for the bearing compensated by orifice restrictor as compared to capillary restrictor when bearing operates in turbulent regime under worn/unworn conditions. From the point of view of stability threshold speed ω¯th, the reduction in the value of ω¯th for capillary compensated bearing is around −3.89 percent whereas for orifice compensated bearing it is −7.85 percent when misaligned worn bearing is operating in turbulent regime.Originality/valueThe present work is original of its kind, in case of misaligned hole‐entry worn journal bearing. The results are quite useful for the bearing designer.
Determinants of knowledge transfer in inter‐firm new product development projects
Authors: Lawson Benn , Potter Antony 
Published: March 2013

PurposeThe purpose of this paper is to explore the factors which determine the degree of knowledge transfer in inter‐firm new product development (NPD) projects. The authors test a theoretical model exploring how inter‐firm knowledge transfer is enabled or hindered by a buyer's learning intent, the degree of supplier protectiveness, inter‐firm knowledge ambiguity, and absorptive capacity.Design/methodology/approachA sample of 153 R&D intensive manufacturing firms in the UK automotive, aerospace, pharmaceutical, electrical, chemical, and general manufacturing industries was used to test the framework. To analyse the data, two‐step structural equation modeling in AMOS 7.0 was used.FindingsThe results indicate that a buyer's learning intent increases inter‐firm knowledge transfer, but also acts as an incentive for suppliers to protect their knowledge. Such defensive measures increase the degree of inter‐firm knowledge ambiguity, encouraging buyer firms to invest in absorptive capacity as a means to interpret supplier knowledge, but also increase the degree of knowledge transfer.Practical implicationsThe paper illustrates the effects of focusing on acquisition, rather than accessing supplier technological knowledge. The paper shows that an overt learning strategy can be detrimental to knowledge transfer between buyer‐supplier, as suppliers react by restricting the flow of information. Organisations are encouraged to consider this dynamic when engaging in multi‐organisational, NPD projects.Originality/valueThe paper examines the dynamics of knowledge transfer within inter‐firm NPD projects, showing how transfer is influenced by the buyer firm's learning intention, supplier's response, characteristics of the relationship and knowledge to be transferred.
Agri‐fresh produce supply chain management: a state‐of‐the‐art literature review
Authors: Shukla Manish , Jharkharia Sanjay 
Published: March 2013

PurposeThe purpose of this paper is to present a literature review of the fresh produce supply chain management (FSCM). FSCM includes the processes from the production to consumption of fresh produce (fruits, flowers and vegetables).Design/methodology/approachLiterature review is done by systematically collecting the existing literature over a period of 20 years (1989‐2009) and classifying it on the basis of structural attributes such as problem context, methodology and the product under consideration. The literature is also categorized according to the geographic region and year of publication.FindingsThere is an increase in interest towards FSCM still there is an absence of a journal with the prime attention towards FSCM. The key finding of this review is that the main interest is towards consumer satisfaction and revenue maximization with post‐harvest waste reduction being a secondary objective. It is revealed from the review that most of the literature is fragmented and is in silos. Lack of demand forecasting, demand and supply mismatch, lesser integrated approach etc are the major causes of concerns.Research limitations/implicationsThe authors have taken only the fresh produce (fruits, flowers and vegetables), authors may also look at other perishable items such as milk, meat, etc.Practical implicationsResult shows a product‐problem‐methodology mapping which may serve as a framework for the managers addressing issues in FSCM.Originality/valueMost of the prior literature reviews are focused on a specific issue such as production planning or inventory management and ignore the broader perspective. There exists a need of having a detailed literature review covering all the operational issues in FSCM. This review fills this gap in the FSCM literature.