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Geoid undulation modeling through the Cokriging methode——A case study of Guayaquil, Ecuador

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Geodesy and Geodynamics 2021年第5期12卷 356-367页

作者： Iván Palacios Orejuela César Leiva González Xavier Buenano Guerra Elena Chicaiza Mora Theofilos Toulkeridis universidad de las fuerzas armadas espe SangolquíEcuador universidad Politécnica de Madrid MadridSpain

The determination of vertical component plays a fundamental role in the initial phase of engineering applications. However, its acquisition is technically and economically demanding, mainly due to the precise heights relative to a reference surface, such as the mean sea level. The Cokriging technique is a necessary input for the calculation of the vertical component of the geodetic control points measured by GNSS, and it requires less auxiliary data and uses complementary available variables for the calculation.Therefore, the main goal is to use Cokriging to establish a geoid undulation prediction model for the rural area of the canton of Guayaquil, Ecuador. Ordinary, Residual and Universal Cokriging and Kriging techniques were used to compare their results and select the best for achieving accuracy. The validation of the application techniques yielded that Universal Cokriging was the most accurate with an RMSE of 8 cm and RSR of 2 cm, obtained just with 66 samples(20% of the dataset). Furthermore, considering the comparison with other regional geoid undulation models, the proposed model increased the accuracy of the results by a ratio of 9.68 and 6.96 in relation to EGM96 and EGM08, respectively.

关键词： Universal Cokriging Kriging Mean sea level GNSS

The need to develop tailored tools for improving the quality of thematic bibliometric analyses: Evidence from papers published in Sustainability and Scientometrics

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Journal of Data and Information Science 2023年第4期8卷 10-35页

作者： Alvaro Cabezas-Clavijo Yusnelkis Milanés-Guisado Ruben Alba-Ruiz Ángel Mdelgado-Vázquez universidad Internacional de La Rioja(UNIR) Avenida de la Paz137Logroño26006Spain universidad Pablo de Olavide Ctra.de UtreraKm 1Sevilla41013Spain Hospital Universitario Virgen de las Nieves Avenida de las Fuerzas Armadas2Granada 18014Spain

Purpose: The aim of this article is to explore up to seven parameters related to the methodological quality and reproducibility of thematic bibliometric research published in the two most productive journals in bibliometrics, Sustainability(a journal outside the discipline) and Scientometrics, the flagship journal in the field.design/methodology/approach: The study identifies the need for developing tailored tools for improving the quality of thematic bibliometric analyses, and presents a framework that can guide the development of such tools. A total of 508 papers are analysed, 77% of Sustainability, and 23% published in Scientometrics, for the 2019-2021 period.Findings: An average of 2.6 shortcomings per paper was found for the whole sample, with an almost identical number of flaws in both journals. Sustainability has more flaws than Scientometrics in four of the seven parameters studied, while Scientometrics has more shortcomings in the remaining three variables.Research limitations: The first limitation of this work is that it is a study of two scientific journals, so the results cannot be directly extrapolated to the set of thematic bibliometric analyses published in journals from all fields.Practical implications: We propose the adoption of protocols, guidelines, and other similar tools, adapted to bibliometric practice, which could increase the thoroughness, transparency, and reproducibility of this type of research.Originality/value: These results show considerable room for improvement in terms of the adequate use and breakdown of methodological procedures in thematic bibliometric research, both in journals in the Information Science area and journals outside the discipline.

关键词： Thematic bibliometric analyses Sustainability Scientometrics Reproducibility Methodological quality

Capuli cherry-mediated green synthesis of silver nanoparticles under white solar and blue LED light

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Particuology 2016年第1期14卷 123-128页

作者： Brajesh Kumar Yolancla Angulo Kumari Smita Luis Cumbal Alexis debut Centro de Nanociencia y Nanotecnologia Universidad de las Fuerzas Armadas-ESPE Av. Gral. Rumifiahui s/n Sangolqui P.O. BOX 171-5-231B Ecuador

In this article, the Capuli （Prunus serotina Ehrh. var. Capuli） cherry extract was used for the synthesis of silver nanoparticles （AgNPs） in the presence of white/visible solar and blue light-emitting diode （LED） light. For the characterization of the extract and the AgNPs, Fourier transform infrared spectroscopy and ultraviolet-visible spectroscopy were employed, along with hydrodynamic particle size analysis, trans- mission electron microscopy and X-ray diffraction. The Ag nanospheres obtained using white light were 40-100 nm in diameter and exhibited an absorption peak at λmax= 445 nm, whereas those obtained using blue LED light were 20-80 nm in diameter with an absorption peak at λmax= 425 nm. Thermal analysis revealed that the content of biomolecules surrounding the AgNPs was about 55-65%, and it was also found that blue LED light AgNPs （56.28%, 0.05 mM） had a higher antioxidant efficacy than the white solar light AgNPs （33.42%, 0.05 mM） against l,l-diphenyl-2-picrylhydrazyl. The results indicate that obtaining AgNPs using a blue LED light may prove to be a simple, cost-effective and easily reproducible method for creating future nanopharmaceuticals.

关键词： Silver nanoparticles Capuli LED light Fourier transform infrared spectroscopy Transmission electron microscopy Antioxidant

Prevalence of the terrain reversal effect in satellite imagery

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International Journal of Digital Earth 2015年第8期8卷 640-655页

作者： Miguel-Angel Bernabé-Poveda Arzu Çöltekin universidad de las fuerzas armadas–espe Departamento de Ciencias de la Tierra y de la ConstrucciónSangolquíPichinchaEcuador Geographic Information Visualization and Analysis Group Department of GeographyUniversity of ZurichSwitzerland

The terrain reversal effect is a perceptual phenomenon which causes an illusion in various 3D geographic visualizations where landforms appear inverted,e.***.we perceive valleys as ridges and vice versa.Given that such displays are important for spatio-visual analysis,this illusion can lead to critical mistakes in interpreting the terrain.However,it is currently undocumented how commonly this effect is experienced.In this paper,we study the prevalence of the terrain reversal effect in satellite imagery through a two-stage online user experiment.The experiment was conducted with the participation of a diverse and relatively large population(n=535).Participants were asked to identify landforms(valley or ridge?)or judge a 3D spatial relationship(is A higher than B?).When the images were rotated by 180°,the results were reversed.In a control task with‘illusion-free’original images,people were successful in identifying landforms,yet a very strong illusion occurred when these images were rotated 180°.Our findings demonstrate that the illusion is acutely present;thus,we need a better understanding of the problem and its solutions.Additionally,the results caution us that in an interactive environment where people can rotate the display,we might be introducing a severe perceptual problem.

关键词： terrain reversal relief inversion false topographic perception phenomenon photo interpretation visual illusion user study

用亚马逊地区水果提取物(Eugenia stipitata McVaugh)细胞体外绿色合成银纳米颗粒（英文）

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Transactions of Nonferrous Metals Society of China 2016年第9期26卷 2363-2371页

作者： Brajesh KUMAR Kumari SMITA Alexis deBUT Luis CUMBAL Centro de Nanociencia y Nanotecnologia Universidad de las Fuerzas Armadas ESPE department of Chemistry TATA College Kolhan UniversityChaibasa- 833202 Jharkhand India

提出一种用亚马逊地区水果提取物（液态）细胞体外合成银纳米颗粒（AgNPs）的生态友好方法,并研究其抗氧化活性。结果表明：AgNPs的紫外-可见光吸收峰与各参数如pH值、温度和时间相关。初始黄色样品在波长为430～450nm范围的强吸收峰、... 详细信息

提出一种用亚马逊地区水果提取物（液态）细胞体外合成银纳米颗粒（AgNPs）的生态友好方法,并研究其抗氧化活性。结果表明：AgNPs的紫外-可见光吸收峰与各参数如pH值、温度和时间相关。初始黄色样品在波长为430～450nm范围的强吸收峰、透射电镜、扫描电镜及X射线衍射分析结果表明,形成了尺寸为15～45nm、球状AgNPs晶体。傅里叶变换红外光谱表明AgNPs的合成与苹果酸、柠檬酸和类胡萝卜素有关。此外,经表面改性的AgNPs（77.42%,1mL）对2,2-二苯基-1-苦肼基的抗氧化效率是Araza果实提取物的（35.30%,1mL）的2倍。此研究为采用Araza果实提取物合成AgNPs提供了可行性,所合成的AgNPs可用作有效的抗氧化剂。

关键词：细胞体外合成银纳米颗粒抗氧化剂生态友好

A Complete Diophantine Characterization of the Rational Torsion of an Elliptic Curve

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Acta Mathematica Sinica,English Series 2012年第1期28卷 83-96页

作者： Irene GARCíA-SELFA Jos M.TORNERO departamento de Matemáticas Universidad de HuelvaFacultad de Ciencias ExperimentalesCampus de El CarmenAvenida de las Fuerzas Armadass/n21071 HuelvaSpain departamento de ' Algebra Universidad de SevillaP.O.116041080 SevillaSpain

We give a complete characterization for the rational torsion of an elliptic curve in terms of the （non-）existence of integral solutions of a system of diophantine equations.

关键词： Elliptic curves diophantine equations

Lantana camara berry for the synthesis of silver nanoparticles

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Asian Pacific Journal of Tropical Biomedicine 2015年第3期5卷 192-195页

作者： Brajesh Kumar Kumari Smita Luis Cumbal Alexis debut Centro de Nanociencia y Nanotecnologia Universidad de las Fuerzas Armadas-ESPE.Av.Gral.Ruminahui s/n

Objective:To synthesize the silver nunoparticles(AgNPs) by reduction of silver ions into nano silver,using ripened berry extract of Lantana camara and evaluate its antioxidant activity against 1.1-diphenyl-2- picrylhydrazyl.Methods:The prepared AgNPs were characterized by visual,UV-visible spectrophotometer.dynamic light scattering and transmission electron microscopy with selected area electron diffraction.Results:Transmission electron microscopy and dynamic light scattering analysis confirmed the AgNPs are spherical and 75.2 nm average sized.Selected area electron diffraction analysis supports that the obtained nanoparticles were in crystalline form.In addition,the antioxidant efficacy of prepared AgNPs was found to be higher than berry extract against 1.1-diphenyl-2-picrylhydrazyl.Conclusions:From the results obtained it is suggested that surface modified AgNPs at lower concentration,showed higher antioxidant activity than berry extract against 1,1-diphenyl-2-picrylhydrazyl and could be used effectively in future ethno pharmacological concerns.

关键词： Green synthesis Lantana camara Silver nanoparticles Transmission electron microscopy DPPH·

Bilinear Model Proposal for Seismic Analysis Using Triple Friction Pendulum (TFP) Bearings

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Open Journal of Civil Engineering 2017年第1期7卷 14-31页

作者： Iván delgado Roberto Aguiar Pablo Caiza departamento de Ciencias de la Tierra y la Construcción universidad de fuerzas Amadas espe Av. Gral. Rumiñ ahui s/n Quito Ecuador

An analytical model is presented for seismic analysis of triple friction pendulum bearings and validated using 81 bearing tests, each subjected to three cycles, with a duration of 12 seconds and using 250, 200 and 100 tons vertical loads. The main objective is to develop formulas for bilinear behavior using maximum, average and minimum friction coefficients to check which is the closest to the real behavior in the laboratory tests and comparatives curves plotting to observe the standard derivation. Parameters such as friction coefficients, effective stiffness, damping factor and vibration periods are analyzed to understand the structural behavior of the TPF bearings.

关键词： Triple Friction Pendulum Bearings

Duodenal duplication cyst and pancreas divisum causing acute pancreatitis in an adult male

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World Journal of Gastrointestinal Endoscopy 2010年第9期2卷 318-320页

作者： Eduardo Redondo-Cerezo Julio Pleguezuelo-Díaz Mercedes López de Hierro José F Macias-Sánchez Cristina Violo Ubia María del Mar Martín-Rodríguez Javier de TeresaGalván Endoscopy Unit Gastroenterology DepartmentHospital Universitario Virgen de las NievesAvenida de las Fuerzas Armadas 2Granada 18014Spain

Duodenal duplication cysts are rare congenital abnormalities which are more commonly diagnosed in infancy and childhood.However,in rare cases,these lesions can remain asymptomatic until adulthood.The combination of duplication cyst and pancreas divisum is extremely rare and both conditions have been linked with acute recurrent pancreatitis.We present the case of a 37 years-old patient who presented with repeated episodes of acute pancreatitis.By means of magnetic resonance imaging and endoscopic ultrasonography we discovered a duplication cyst whose cavity received drainage from the dorsal pancreas.After opening the cyst cavity to the duodenal lumen with a needle knife the patient presented no further episodes in the clinical follow-up.Comparable literature findings and therapeutic options for these abnormalities are discussed with regard to the presented case.

关键词： Duplication cyst Pancreas divisum Acute recurrent pancreatitis Endoscopic ultrasonography