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Optimization of the Performance of Marine Diesel Engines to Minimize the Formation of SO_x.Emissions

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Journal of Marine Science and Application 2020年第3期19卷 473-484页

作者： Mina Tadros Manuel Ventura C.Guedes soares Centre for Marine Technology and Ocean Engineering(CENTEC) Instituto Superior TécnicoUniversidade de Lisboa1049-001 LisboaPortugal

Optimization procedures are required to minimize the amount of fuel consumption and ex.aust emissions from marine *** study discusses the procedures to optimize the performance of any marine engine implemented in a 0D/1D numerical model in order to achieve lower values of ex.aust *** that point,an ex.ension of previous simulation researches is presented to calculate the amount of SOx.emissions from two marine diesel engines along their load diagrams based on the percentage of sulfur in the marine fuel *** variations of SOx.emissions are computed in g/k W·h and in parts per million(ppm)as functions of the optimized parameters:brake specific fuel consumption and the amount of air-fuel ratio ***,a surrogate model-based response surface methodology is used to generate polynomial equations to estimate the amount of SOx.emissions as functions of engine speed and *** developed non-dimensional equations can be further used directly to assess the value of SOx.emissions for different percentages of sulfur of the selected or similar engines to be used in different marine applications.

关键词： Marine diesel engine Standard procedures SO_x.emissions Surrogate model Response surface methodology

x.D and x.S Analysis of TiO2 Thin Films Annealed in Different Environments

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材料科学与工程（中英文B版） 2014年第6期4卷 163-170页

作者： tamara Potlog Petru Dumitriu Marius Dobromir Dumitru Luca Department of Physics and Engineering Moldova State University MD 2009 Chisinau Moldova Faculty of Physics Alexandru loan Cuza University lasi 700506 Romania

Multiple Imputation of Missing Data:A Simulation Study on a Binary Response

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Open Journal of Statistics 2013年第5期3卷 370-378页

作者： Jochen Hardt Max.Herke tamara Brian Wilfried Laubach Medizinische Psychologie und Medizinische Soziologie Klinik fur Psychosomatische Medizin und PsychotherapieUniversitatsmedizin MainzMainzGermany

Currently, a growing number of programs become available in statistical software for multiple imputation of missing values. Among others, two algorithms are mainly implemented: Ex.ectation Max.mization (EM) and Multiple Imputation by Chained Equations (MICE). They have been shown to work well in large samples or when only small proportions of missing data are to be imputed. However, some researchers have begun to impute large proportions of missing data or to apply the method to small samples. A simulation was performed using MICE on datasets with 50, 100 or 200 cases and four or eleven variables. A varying proportion of data (3% - 63%) was set as missing completely at random and subsequently substituted using multiple imputation by chained equations. In a logistic regression model, four coefficients, i.e. non-zero and zero main effects as well as non-zero and zero interaction effects were ex.mined. Estimations of all main and interaction effects were unbiased. There was a considerable variance in the estimates, increasing with the proportion of missing data and decreasing with sample size. The imputation of missing data by chained equations is a useful tool for imputing small to moderate proportions of missing data. The method has its limits, however. In small samples, there are considerable random errors for all effects.

关键词： Multiple Imputation Chained Equation Large Proportion Missing Main Effect Interaction Effect

Reduced Recombination Current Due to Sputtered CdO Nanolayer at CdS/CdTe Interface

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Materials Sciences and Applications 2023年第3期14卷 186-207页

作者： Amjad Al-Qassem Vladimir Fedorov Ludmila Gagara tamara Potlog Physics Department and Engineering Moldova State University Chisinau Republic of Moldova Institute of Electronic Engineering and Nanotechnologies Chisinau Republic of Moldova

In this paper, interface engineering via sputtering of CdO nanolayer at the buffer-CdS/CdTe-absorber interface is demonstrated as an efficient approach to improve the performance of solar cell device. The i-CdO interfacial layer with various thicknesses from 5 nm to 35 nm was deposited by DC magnetron sputtering. Comparative studies on TCO/CdS/CdTe and TCO/CdS/CdO/CdTe interfaces have been conducted by current-voltage, capacitance-voltage and admittance spectroscopy measurements. The current-voltage characteristics of the devices with an area of 0.45 cm2 under 100 mW/cm2 illumination, at the optimum thickness of CdO intermediate layer in the proposed structures, show increases of the short circuit current density and the open circuit voltage by 5% and 25%, respectively. The efficiency improvement of 3.1% of p-i-n cell over p-n cell is observed. Results of the temperature-dependent current-voltage and admittance measurements revealed the removing of the deep level defect with the activation energy of 0.43 eV and the reducing of the ideality factor from 1.9 to 1.8 via buffer/absorber interfacial passivation method. Interface passivation appears to be critical to improve the short circuit current density and the open circuit voltage, and CdO thin film is clearly effective for this purpose.

关键词： CdS/CdTe Photovoltaic Devices CdO Interface Engineering Defects

Nucleation of methane hydrate and ice in emulsions of water in crude oils and decane under non-isothermal conditions

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Chinese Journal of Chemical Engineering 2019年第3期27卷 668-676页

作者： Andrey S. Stoporev Lidiya I. Svarovskaya Larisa A. Strelets Lubov’ K. Altunina Galina V. Villevald tamara D. Karpova Tatyana V. Rodionova Andrey Yu. Manakov Nikolaev Institute of Inorganic Chemistry SB RAS Novosibirsk State University Institute of Petroleum Chemistry

Achievable supercooling for the formation of methane hydrate from water emulsions was studied in seven different crude oils and in decane. The ex.eriments were performed under constant rate cooling from + 20 to-15 °C and a pressure of methane of 12 MPa. It was demonstrated that the shapes and positions of the resulting survival curves depend on the density, viscosity and dispersive power of oil samples used in the ex.eriments, as well as on the degree of oil ox.dation. In addition, results of the ex.eriments on ice freezing under the same emulsions are presented. The results obtained in the work allowed us to discuss the possibility and features of primary and secondary nucleation of the hydrate and ice in the systems under consideration.

关键词： Methane hydrate Crude oil Oil dispersive system Nucleation

Ex.racavity Parametric Oscillation with Continuous and/or Discontinuous Frequency Tuning

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Optics and Photonics Journal 2012年第2期2卷 119-122页

作者： Valerik S. Ayrapetyan tamara A. Shirokova Siberian State Academy of Geodesy 10 Novosibirsk Russia

A continuously or/and discontinuously tunable LiNbO3 Optical Parametric Oscillator (OPO) with the spectral range of 1.42 - 4.24 um and shifting of 0…12 nm is created and investigated. The OPO resonator ring circuit provides for the radiation energy output value of up to 50 mJ. Radiation bandwidth narrowing of up to 0.7 cm–1 by introducing of the Fabry-Perot etalon into the OPO resonator has been obtained.

关键词： Optical Parametric Oscillator Fabry-Perot Etalon Analog-Digital Converter

Recent Developments in Fatigue Assessment of Ships and Offshore Structures

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Journal of Marine Science and Application 2022年第4期21卷 3-25页

作者： Yan Dong Y.Garbatov C.Guedes soares Yantai Research Institute of Harbin Engineering University Harbin Engineering UniversityYantaiChina College of Shipbuilding Engineering Harbin Engineering UniversityHarbinChina Centre for Marine Technology and Ocean Engineering(CENTEC) Instituto Superior TécnicoUniversidade de LisboaLisbonPortugal HEU-UL International Joint Laboratory of Naval Architecture and Offshore Technology HarbinChina

A review is provided of various approaches that have been adopted recently to assess the fatigue of ships and offshore *** relevant fatigue loading is reviewed first,focusing on the successive loading and unloading of the cargo and the transient *** factors influencing fatigue strength are discussed,including the geometrical parameters,material,residual stress,and ones related to the *** approaches for fatigue analyses of seam-welded joints are covered,i.e.,the structural stress or strain approach,the notch stress or strain approach,notch intensity approach,and the crack propagation approach.

关键词： Ships and offshore structures Fatigue loading Influencing factors Fatigue analysis approaches

Inversion of the paleo-geothermal gradient using low-temperature thermochronology: A case study of the Haiyuan -Liupanshan region

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Journal of Earth Science 2023年

作者： Rux.n Ding Zhenghai Wang Kyoungwon Min Nina Liu Cleber soares Jing Liu-Zeng Weitao Wang Guangdong Provincial Key Lab of Geodynamics and Geohazards， School of Earth Sciences and Engineering， Sun Yat-sen University Guangdong Provincial Key Laboratory of Mineral Resources & Geological Processes Southern Laboratory of Ocean Science and Engineering Department of Geological Sciences， University of Florida ChronusCamp Research-Thermochronology Analysis LTD School of Earth System Science， Tianjin University

The paleo-geothermal gradient is a crucial parameter for converting the thermal history to the ex.umation history. However， the precise estimation of this parameter has been a challenge. This paper presents a simple two-step method to model the paleo-geothermal gradient using low-temperature thermochronology. (1) It uses the Monte Carlo approach to generate thermal histories in a vertical section randomly and calculates the entire thermal history within the goodness-of-fit thresholds based on different paleo-geothermal gradients. (2) It selects the optimum paleo-geothermal gradient by comparing the entire thermal history within different goodness-of-fit thresholds. We validated the method with apatite (U-Th)/He and fission track data collected from two drill cores in the Haiyuan-Liupanshan region. The result revealed that the best-fit paleo-geothermal gradient was ～42 ℃/km during the Early Cretaceous–Miocene and has decreased rapidly to 20 ℃/km since ～10 Ma. The crust thickening in the study area may ex.lain the rapid reduction in the paleo-geothermal gradient since ～10 Ma. Our results are consistent with earlier studies in the region， suggesting that our simple and more intuitive approach provides an alternative method for paleo-geothermal gradient modeling.

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Ni/Carbon Hybrid Prepared by Hydrothermal Carbonization and Thermal Treatment as Support for PtRu Nanoparticles for Direct Methanol Fuel Cell

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Journal of Materials Science & Technology 2013年第8期29卷 747-751页

作者： Marcelo Marques Tusi Michele Brandalise Nataly soares de Oliveira Polanco Olandir Vercino Correa Antonio Carlos da Silva Juan Carlo Villalba Fauze Jaco Anaissi Almir Oliveira Neto Estevam Vitorio Spinac Universidade Regional Integrada do Alto Uruguai e das Missoes-URI Av.Batista Bonoto Sobrinhos/nSao Vicente97700-000 SantiagoRSBrazil Instituto de Pesquisas Energticas e Nucleares-IPEN/CNEN-SP Av.Prof.Lineu Prestes2242Cidade Universitria05508-900 Sao PauloSPBrazil Universidade Estadual do Centro-Oeste-UNICENTRO R.Simeao Varela de S 03Vila Carli85040-080 GuarapuavaPRBrazil

Ni/Carbon was prepared in two steps： initially cellulose as carbon source and NiCl2·6H2O as catalyst of the carbonization process were submitted to hydrothermal treatment at 200 ℃ and further to thermal treatment at 900 ℃ under argon atmosphere. The obtained material contains Ni nanoparticles with face-centered cubic （fcc） structure dispersed on amorphous carbon with graphitic domains. PtRu/C electrocatalysts （carbon- supported PtRu nanoparticles） were prepared by an alcohol-reduction process using Ni/Carbon as support. The materials were characterized by thermogravimetric analysis, energy-dispersive x.ray spectroscopy, Fourier transform infrared spectroscopy, x.ray diffraction, transmission electron microscopy and tested as anodes in single direct methanol fuel cell （DMFC）. The performances of PtRu/C electrocatalysts using Ni/Carbon as support were superior to those obtained for PtRu/C using commercial carbon black Vulcan x.72 as support.

关键词： Cellulose Hydrothermal carbonization Alcohol-reduction process PtRu/C electrocatalysts Direct methanol fuel cell