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Technical efficiency of cocoa farms at varying elevation levels in Davao City, Philippines: implications to sustainable upland farming systems

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Journal of mountain Science 2024年第1期21卷 33-48页

作者： Francis Levi A.DURAnO Jon marx SARmIEnTO Larry n.DIGAL pedro A.ALVIOLA IV School of management University of the Philippines MindanaoDavao City 8000Philippines

Elevation is one of many components that influence agriculture, and this in turn affects the level of both inputs and outputs of farmers. This article focuses on the productivity and technical efficiency of 100 cocoa farms using cross-sectional data from areas ranging from 190 to 1021 m above sea level which were classified as low, medium, and high elevation in Davao City, considered as the chocolate capital of the Philippines. Using stochastic frontier analysis, the results showed that the cost of inputs per ha and the number of cocoa trees per ha significantly increase yield. Farms at high elevations were less technically efficient, as this entails lower temperatures and increased rainfall, and cocoa farming in those areas and conditions can be more challenging, especially with changes in farming practices, terrain, and distance to markets. Other significant variables were age of cocoa farms, married farmers, and age of the farmers. Older farms may be more developed, farmers who are married benefit from their spouses being able to readily contribute as farm labor, and lastly, older farmers' inefficiency may likely stem from nonadaptation of newer farming practices. With an average technical efficiency of 0.61, 0.63, and 0.26 in low, medium, and high elevation areas, respectively, farmers therefore have an incentive to improve farm practices and consider topographical variations found in high elevation areas. Recommendations for the improvement of technical efficiency of cocoa farms are better connectivity to markets, enhancing farm practices, and continuation and improvement of government programs on cocoa with an added emphasis on research. For farmers in high elevation areas, mitigating solutions such as sustainable agriculture practices and ecolabelling are key to improving efficiency and minimizing the potential negative impact on upland farming systems. moreover, such adaptation measures may also contribute to sustainability of cocoa farming in high elevation

关键词： Cocoa farms Cobb-Douglas production function Elevation Philippines Stochastic frontier analysis Technical efficiency

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Solar-assisted photocatalytic water splitting using defective UiO-66 solids from modulated synthesis

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nano Research 2024年第5期17卷 4134-4150页

作者： Celia m.Rueda-navarro maría Cabrero-Antonino Paula Escamilla Valentín Díez-Cabanes Dong Fan pedro Atienzar Belén Ferrer Ignacio Vayá Guillaume maurin Herme G.Baldoví Sergio navalón Departamento de Química Universitat Politècnica de ValènciaCamino de Vera s/nValencia 46022Spain Instituto de Ciencia molecular(ICmOL) Universitat de ValènciaPaterna 46980Spain ICGm Univ.MontpellierCNRSENSCMMontpellier34095France Instituto de Tecnología Química(UPV-CSIC) Universitat Politècnica de ValènciaAvenida de los Naranjos s/nValencia 46022Spain

metal-organic frameworks(mOFs)are attracting increasing interests as photocatalysts for solar-driven hydrogen production from *** paper reports on a comparative study of using either acetic acid(AA)or trifluoroacetic acid(TFA)as the representative UiO-66 organic modulators for synthesizing visible light responsive UiO-66(Zr)-X(X:nH_(2) or nO_(2))photocatalysts for water *** results show that photocatalytic hydrogen generation from a water/methanol mixture can be improved by varying the nature and amount of the modulator employed to prepare the different UiO-66(Zr)-X(X:nH_(2) or nO_(2))solid ***-66(Zr)-nH_(2) was the most active photocatalyst,followed by UiO-66(Zr)-nO_(2),both prepared with 12 equivalents of AA with respect to the organic *** UiO-66(Zr)-nH_(2) solid was more active than the parent mOF in photocatalytic overall water splitting(OWS)(H_(2) and O_(2) production of 450 and 160μmol·g^(-1),respectively,in 5 h;apparent quantum yield(AQY)at 400 nm of 0.06%)in the absence of methanol and compares favourably with analogous *** on the photocatalytic activity of the most active solids of both series was obtained by means of a series of techniques,including ultraviolet-visible(UV-vis)diffuse reflectance,X-ray photoelectron spectroscopy(XPS),laser flash photolysis(LFP),electron spin resonance(ESR),photoluminescence and photoelectrochemical measurements together with density functional theory(DFT)*** results showed that organic acid modulators can be used to enhance the photocatalytic activity of missing linker UiO-66 defective materials in solar-powered water splitting.

关键词： heterogeneous photocatalysis metal-organic frameworks(mOFs) UiO-66 materials carboxylic acid modulators water splitting solar light

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The effectiveness of different wear indicators in quantifying wear on railway wheels of freight wagons

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Railway Engineering Science 2024年第3期32卷 307-323页

作者： Philipe Augusto de Paula Pacheco m.magelli matheus Valente Lopes pedro Henrique Alves Correa n.Zampieri n.Bosso Auteliano Antunes dos Santos Federal Institute of the Southeast of minas Gerais(IF Sudeste mG) Técnico PanamáStreet 45Santos DumontMG 36246-311Brazil Railway Laboratory(Lafer) Universidade Estadual de Campinas(UNICAMP)Mendeleyev Street 200CampinasSP 13083-872Brazil Department of mechanical and Aerospace Engineering Politecnico Di TorinoC.so Duca degli Abruzzi 2410129 TurinItaly

Railway infrastructure relies on the dynamic interaction between wheels and rails;thus,assessing wheel wear is a critical aspect of maintenance and *** paper focuses on the wheel-rail wear indicator T-gamma(Tγ).Amidst its use,it becomes apparent that Tγ,while valuable,fails to provide a comprehensive reflection of the actual material removal and actual contact format,which means that using only Tγas a target for optimization of profiles is not *** this work,three different freight wagons are evaluated:a meter-gauge and a broad-gauge heavy haul vehicles from South American railways,and a standard-gauge freight vehicle operated in Europe,with different axle loads and dissimilar new wheel/rail *** vehicles are subjected to comprehensive multibody simulations on various *** simulations aimed to elucidate the intricate relationship between different wear indicators:Tγ,wear index,material removal,and maximum wear depth,under diverse curves,non-compensated lateral accelerations(A_(nc)),and *** findings showed a correlation of 0.96 between Tγand wear depth and 0.82 between wear index and material removed for the outer *** the results,the Tγis better than the wear index to be used when analyzing wear depth while the wear index is more suited to foresee the material *** results also show the low influence of A_(nc)on wear index and Tγ.By considering these factors together,the study aims to improve the understanding of wheel-rail wear by selecting the best wear analysis approaches based on the effectiveness of each parameter.

关键词： Wear index Wear volume Wear modeling Dynamic simulation

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Ca-based materials derived from calcined cigarette butts for CO_(2)capture and thermochemical energy storage

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Journal of Environmental Sciences 2024年第6期140卷 230-241页

作者： nabil Amghar Virginia moreno pedro E.Sánchez-Jiménez Antonio Perejón Luis A.Pérez-maqueda Instituto de Ciencia de materiales de Sevilla C.S.I.C.-Universidad de SevillaC.Américo Vespucio4941092 SevillaSpain Instituto de Tecnología de materiales(ITm) Universitat Politècnica de València(UPV)Plaza Ferrándiz y Carbonell 1AlcoyAlicante 03801Spain Departamento de Química Inorgánica Facultad de QuímicaUniversidad de Sevilla41012 SevillaSpain

Cigarette butts(CBs)are one of the most common types of litter in the *** to the toxic substances they contain,the waste generated poses a harmful risk to the environment,and therefore there is an urgent need for alternative solutions to landfill ***,this work presents a possible revalorization of this waste material,which implies interesting environmental *** were used as sacrificial templates for the preparation of CaO-based materials by impregnation with calcium and magnesium nitrates followed by flaming *** materials presented enhanced porosity for their use in the Calcium Looping process applied either to thermochemical energy storage or CO_(2)capture *** influence of the concentration of Ca and mg in the impregnating solutions on the multicycle reactivity of the samples was *** improved multicycle performance was obtained in terms of conversion for both applications.

关键词： Cigarette butts Calcium-Looping CO_(2)Capture Thermochemical energy storage

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Employing electrochemically derived pH gradients for Lab-on-PCB protein preconcentration devices

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microsystems & nanoengineering 2024年第1期10卷 79-87页

作者： Grace maxted pedro Estrela Despina moschou Department of Electronic and Electrical Engineering University of BathBath BA27AYUK Centre for Bioengineering and Biomedical Technologies(CBio) University of BathBath BA27AYUK

Protein preconcentration is an essential sample preparation step for analysis in which the targeted proteins exist in low concentrations,such as bodily fluids,water,or ***,very few practical implementations of miniaturized protein preconcentration devices have been demonstrated in practice,and even fewer have been integrated with other microanalytical *** approaches rely heavily on additional chemicals and reagents and introduce complexity to the overall *** this paper,we propose a novel miniaturized isoelectric focusing-based protein preconcentration screening device based on electrochemically derived pH gradients rather than existing chemical reagent *** this way,we reduce the need for additional chemical reagents to zero while enabling device incorporation in a seamlessly integrated full protein analysis microsystem via Lab-on-PCB *** apply our previously presented Lab-on-PCB approach to quantitatively control the pH of a solution in the vicinity of planar electrodes using electrochemical acid generation through redox-active self-assembled *** presented device comprises a printed circuit board with an array of gold electrodes that were functionalized with 4-aminothiophenol;this formed a self-assembled monolayer that was electropolymerized to improve its electrochemical *** preconcentration was performed in two *** first was open and needed the use of a holder to suspend a well of fluid above the electrodes;the second used microfluidic channels to enclose small volumes of *** here are the resulting data for protein preconcentration in both these forms,with a quantitative concentration factor shown for the open form and qualitative proof shown for the microfluidic.

关键词： electrochemical proof qualitative

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Conformational dynamics as an intrinsic determinant of prion protein misfolding and neurotoxicity

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neural Regeneration Research 2024年第10期19卷 2095-2096页

作者： Alessandro Cembran pedro Fernandez-Funez Department of Chemistry and Biochemistry University of Minnesota DuluthDuluthMNUSA Department of Biomedical Sciences University of Minnesota Medical SchoolDuluth CampusDuluthMNUSA

The prion protein(PrP) is the key molecular and pathological mediator of prion diseases,a heterogeneous group of brain disorders with fatal *** diseases are rare but deserve special attention because of their unique f... 详细信息

关键词： folding intrinsic dynamics

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Effect of the Coulomb and dielectric forces on the onset of Rayleigh-Bénard convection

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Acta mechanica Sinica 2024年第6期40卷 64-77页

作者： Zhonglin Du pedro A.Vázquez Jian Wu School of Energy Science and Engineering Harbin Institute of TechnologyHarbin150001China Heilongjiang Key Laboratory of micro-and nano-scale Fluid Flow and Heat Transfer Harbin150001China Departamento de Física Aplicada III ETSIIUniversidad de SevillaSevilla41092Spain

In this paper,the effect of Coulomb and dielectric forces on the onset of Rayleigh-Bénard convection(RBC)in a dielectric liquid layer contained between two parallel electrode plates has been numerically *** different operating conditions have been considered in electrohydrodynamic(EHD)conduction:ohmic and saturation,and variations in the physical properties of the dielectric fluid with *** electric equations and the state equations based on the Boussinesq approximation are integrated in the framework of OpenFOAm buoyantBoussinesqPimpleFoam *** results show that in the ohmic regime,the combined effect of Coulomb and dielectric forces promotes the onset of RBC flow,while in the saturation state,the inhibition of RBC flow by Coulomb force is more *** value of the critical Rayleigh number Ra decreases with increasing electric Reynolds number ReE in the ohmic regime,whereas in the saturation state,the critical Ra increases with increasing *** the saturation regime,the flow field always has a steady flow in the range of parameters ***,the onset of the RBC flow promoted by the dielectric force is more pronounced in the ohmic *** to the presence of the dielectric force,the flow field exhibits periodic oscillatory flow at low electric Reynolds numbers for the range of parameters considered.

关键词： EHD conduction Dielectric force Rayleigh-Bénard convection OpenFOAm

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Distributed phase-matching measurement for dynamic strain and temperature sensing based on stimulated Brillouin scattering enhanced four-wave mixing

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Photonics Research 2024年第1期12卷 141-153页

作者： YUAn WAnG pedro TOVAR JUnTOnG YAnG LIAnG CHEn XIAOYI BAO nexus for Quantum Technologies University of OttawaOttawaOntario K1N 6N5Canada

A Brillouin dynamic grating(BDG) can be used for distributed birefringence measurement in optical fibers,offering high sensitivity and spatial resolution for sensing ***,it is quite a challenge to simultaneously achieve dynamic measurements with both high accuracy and high spatial *** this work,we propose a sensing mechanism to achieve distributed phase-matching measurement using a chirped pulse as a probe *** BDG reflection,the peak reflection corresponds to the highest four-wave mixing(FWm) conversion efficiency,and it requires the Brillouin frequency in the fast and slow axes to be equal,which is called the phase-matching *** condition changes at different fiber positions,which requires a range of frequency injection for the probe *** proposed method uses a chirped pulse as a probe wave to cover this frequency range associated with distributed birefringence *** allows us to detect distributed phase matching for birefringence changes that are introduced by temperature and strain *** to the single shot and direct time delay measurement capability,the acquisition rate in our system is only limited by the fiber ***,unlike conventional BDG spectrum recovery-based systems,the spatial resolution here is determined by both the frequency chirping rate of the probe pulse and the birefringence profile of the *** the experiments,an acquisition rate of 1 k Hz(up to fiber length limits) and a spatial resolution of 10 cm using a 20 ns probe pulse width are *** minimum detectable temperature and strain variation are 5.6 mK and 0.37 με along a 2 km long polarization-maintaining fiber(PmF).

关键词： fiber scattering polarization

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Inversion of walkaway VSP data in the presence of lateral velocity heterogeneity

Energy Geoscience

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Energy Geoscience 2024年第2期5卷 304-313页

作者： Vladimir Grechka Ilya Tsvankin pedro Contreras CWP Department of GeophysicsColorado School of MinesGoldenCO80401USA PDVSA-InTEVEP Apartado 76343Caracas1070AVenezuela Borehole Seismic LLC USA Department of Physics ULAVenezuela

multi-azimuth walkaway vertical seismic profiling is an established technique for the estimation of in situ slowness surfaces and inferring anisotropy ***,this technique requires the assumption of lateral homogeneity,which makes the horizontal slowness components at depths of downhole receivers equal to those measured at the *** violations of this assumption,such as lateral heterogeneity or nonzero dip of intermediate interfaces,lead to distortions in reconstructed slowness surfaces and,consequently,to errors in estimated anisotropic *** this work,we relax the assumption of lateral homogeneity and discuss how to correct vertical seismic profile data for weak lateral *** describe a procedure of downward continuation of recorded traveltimes that accounts for the presence of both vertical inhomogeneity and weak lateral heterogeneity,which produces correct slowness surfaces at depths of downhole receivers,noticing that sufficiently dense receiver coverage along a borehole is required to separate influences of vertical and lateral heterogeneity on measured traveltimes and obtain accurate estimates of the slowness *** the slowness surfaces are found and a desired type of anisotropic model to be inverted is selected,the corresponding anisotropic parameters,providing the best fit to the estimated slownesses,can be *** invert the slowness surfaces of P-waves for parameters of the simplest anisotropic model describing dipping fractures(transversely isotropic medium with a tilted symmetry axis).Five parameters of this model,namely,the P-wave velocity V0 in the direction of the symmetry axis,Thomsen's anisotropic coefficients e and d,the tilt n,and the azimuth b of the symmetry axis,can be estimated in a stable manner when maximum source offset is greater than half of receiver depth.

关键词： Walkaway vertical seismic profile Lateral velocity heterogeneity Anisotropic parameter estimation Vertical inhomogeneity

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new pharmacological tools:the use of diterpenes to promote adult hippocampal neurogenesis

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neural Regeneration Research 2024年第8期19卷 1629-1630页

作者： Ricardo Gomez-Oliva pedro nunez-Abades Carmen Castro Department of Biomedicine Biotechnology and Public HealthDivision of PhysiologyUniversity of CadizCadizSpain Biomedical Research and Innovation Institute of Cadiz(IniBICA) CadizSpain Department of Physiology University of SevilleSevilleSpain

Tissue regeneration maintains homeostasis and preserves the functional features of each ***,not all tissues show a strong repairing *** is the case of the central nervous *** is now well established that the generation of new functional neurons from stem cells in the adult brain occurs in specific regions of the brain of different species such as rodents,birds,primates,and humans(Eriksson et al.,1998).

关键词： capacity maintain preserve

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