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Modeling and optimization of non-isothermal convective drying process of Lavandula×allardii

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Information Processing in Agriculture 2024年第1期11卷 1-13页

作者： Vasileios Chasiotis Konstantinos-Stefanos Nikas Andronikos filios Laboratory of Thermo Fluid Systems(LTFS) Department of Mechanical EngineeringUniversity of West AtticaAncient Olive Grove CampusThivon Str.250GR12244 EgaleoGreece

Non-isothermal convective drying schemes were examined for Lavandula×allardii leaves and *** process parameters were optimized using response surface methodology(RSM)to ensure the peak operational *** effects of temperature increase rate(2–4°C/h)and the airflow velocity(1–3 m/s)on the essential oil yield,drying duration and consumption,were investigated.A face-centered central composite design was deployed and the experimental data was adapted to the most suitable polynomial models,as determined by the regression *** of variance was applied to assess the effects of the process variables,their interactions and the statistical significance of the examined *** factors of temperature increase rate and airflow velocity had a significant impact on the drying *** velocity had a greater effect on leaves’essential oil yield and inflorescences’process energy consumption,whereas the rates of temperature increase had a greater influence on the inflorescences’essential oil yield and leaves’energy *** minimum drying duration and energy consumption were obtained for the maximum temperature increasing rate at 3 and 1 m/s airflow velocities respectively;and the highest essential oil yield was obtained for the least rate of temperature increase and airflow velocity for both leaves and *** optimization was performed for minimizing drying duration and energy consumption by maximizing the essential oil *** rate of temperature increases of 4°C/h and the airflow velocity of 1 m/s,were proposed as the optimum non-isothermal drying conditions for both leaves and inflorescences of Lavandula×*** values of essential oil content have been 1.387/3.05 mL/g,4.21/4.18 h drying time and 0.809/0.732 kWh energy consumption at the optimum operation point for leaves and inflorescences,*** resulted optimized non-stationary temperature scheme considerably improved the drying

关键词： Convective drying Non-isothermal drying Lavender Essential oil Process optimization

Convection in the Rayleigh-Bénard Flow with all Fluid Properties Variable

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Journal of Thermal Science 2011年第5期20卷 454-459页

作者： athanasios Sassos Asterios Pantokratoras Mechanical Engineering Department Kavala Institute of Technology School of Engineering Democritus University of Thrace

In the present paper, the effect of variable fluid properties （density, viscosity, thermal conductivity and specific heat） on the convection in the classical Rayleigh-Benard problem is investigated. The investigation concerns water, air, and engine oil by taking into account the variation of fluid properties with temperature. The results are obtained by numerically solving the governing equations, using the SIMPLE algorithm and covering large temperature differences. It is found that the critical Rayleigh number increases as the temperature difference increases considering all fluid properties variable. However, when the fluid properties are kept constant, calculated at the mean temperature, and only density is considered variable, the critical Rayleigh number either decreases or remains constant.

关键词： Rayleigh-Benard variable properties onset numerical investigation.

Endovascular abdominal aortic aneurysm repair in the geriatric population

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Journal of Geriatric Cardiology 2012年第3期9卷 285-291页

作者： athanasios Saratzis SaifMohamed Warwickshire Vascular and Endovascular Unit University Hospital Coventry & Warwickshire Coventry CV22DX United Kingdom

Abdominal aortic aneurysm （AAA） is a relatively common pathology among the elderly. More people above the age of 80 will have to undergo treatment of an AAA in the future. This review aims to summarize the literature focusing on endovascular repair of AAA in the geriatric population. A systematic review of the literature was performed, including results from endovascular abdominal aortic aneurysm repair （EVAR） registries and studies comparing open repair and EVAR in those above the age of 80. A total of 15 studies were identified. EVAR in this population is efficient with a success rate exceeding 90% in all cases, and safe, with early mortality and morbidity being superior among patients undergoing EVAR against open repair. Late survival can be as high as 95% after 5 years. Aneurysm-related death over long-term follow-up was low after EVA_R, ranging fi＇om 0 to 3.4%. Endovascular repair can be offered safely in the geriatric population and seems to compare favourably with open repair in all studies in the literature to date.

关键词： Abdominal aortic aneurysm Octogenarians Geriatric population

REMARKS ON THE CONTRIBUTIONS OF CONSTANTINE *** TO THE SUBJECT OF CONSERVATION LAWS

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Acta Mathematica Scientia 2012年第1期32卷 3-14页

作者： athanasios E.Tzavaras Department of Applied Mathematics University of Crete and Institute for Applied and Computational Mathematics

Constantine M. Dafermos has done extensive research at the interface of partial differential equations and continuum physics. He is a world leader in nonlinear hyperbolic conservation laws, where he introduced several fundamental methods in the subject including the methods of relative entropy, generalized characteristics, and wave-front tracking, as well as the entropy rate criterion for the selection of admissible wave fans. He has also made fundamental contributions on the mathematical theory of the equations of thermomechanics as it pertains in modeling and analysis of materials with memory, thermoelasticity, and thermoviscoelasticity. His work is distinctly characterized by an understanding of the fundamental issues of continuum physics and their role in developing new techniques of mathematical analysis.

关键词： REMARKS ON THE CONTRIBUTIONS OF CONSTANTINE M.DAFERMOS TO THE SUBJECT OF CONSERVATION LAWS

BOUND STATES FOR A CLASS OF QUASILINEAR SCALAR FIELD EQUATIONS WITH POTENTIALS VANISHING AT INFINITY

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Acta Mathematica Scientia 2012年第1期32卷 197-208页

作者： athanasios N.Lyberopoulos Department of Mathematics University of the Aegean

We study the existence and non-existence of bound states （i.e., solutions in W1,P（RN）） for a class of quasilinear scalar field equations of the for -△pu＋V（x）｜u｜p-2u=a（x）｜u｜q-2u,x∈RN,1〈P〈N,mwhen the po... 详细信息

关键词： p-Laplacian bound states decaying potentials Hardy potential weightedSobolev spaces

Confined masonry as practical seismic construction alternative-the experience from the 2014 Cephalonia Earthquake

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Frontiers of Structural and Civil Engineering 2018年第3期12卷 270-290页

作者： Fillitsa KARANTONI Stavroula PANTAZOPOULOU athanasios GANAS Department of Civil Engineering University of Patras Rio Achaia 26504 Greece The Lassonde Faculty of Engineering Deptartment of Civil Engineering York University Toronto M3J 1P3 Canada Institute of Geodynamics National Observatory of Athens Athens Greece

During August 1953 three strong earthquakes of magnitude ranging from 6.3 to 7.2 shook the Ionian Island of Cephalonia （Kefalonia）, Greece, and destroyed almost the entire building stock of the Island which consisted primarily of traditional unreinforced masonry （URM） houses. The authorities went on to restructuring of the building stock, using a structural system that is most like what is known today as confined masonry. They designed about 14 types of one- to two-storey buildings providing the engineers with detailed construction plans. These buildings are known as ＂Arogi＂ buildings （Arogi in Greek meaning Aid）. On the 24th of January and 3rd of February 2014, two earthquakes of magnitude 6.1 and 6.0 struck the island, causing significant soil damages, developing excessively high ground accelerations. Surprisingly, no damage was reported in the ＂Arogi＂ buildings. The seismic behavior of the buildings is examined by FEM linear analysis and it is compared to that of URM structures. Computed results illustrate that the displacements of identical URM buildings would be about twice the magnitudes observed in the corresponding ＂Arogi＂ ones, with the implication that the earthquake sequence of 2014 would have caused critical damage should the type of structure be of the URM type. Furthermore, it is illustrated that this low cost alternative method of construction is a very effective means of producing earthquake resilient structures, whereas further reduction of seismic displacement may be achieved in the order of 50% with commensurate effects on damage potential, when reinforced slabs are used to replace the timber roofs.

关键词： Cephalonia confined masonry comparative FEM analysis unreinforced masonry seismic damage

Exploring injury severity of children and adolescents involved in traffic crashes in Greece

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Journal of Traffic and Transportation Engineering(English Edition) 2021年第4期8卷 596-604页

作者： athanasios Theofilatos Constantinos Antoniou George Yannis School of Architecture Building and Civil EngineeringLoughborough UniversityLeicestershire LE113TUUK Department of Civil Geo and Environmental EngineeringTechnical University of MunichMunich 80333Germany Department of Transportation Planning and Engineering School of Civil EngineeringNational Technical University of AthensZografou 15773Greece

For the purpose of exploring the factors affecting injury severity of children and adolescents involved in traffic crashes in Greece,disaggregate crash data including 13,431 involving children and adolescents from all regions of Greece for the period 2006–2015 were *** order to identify factors affecting injury severity and account for potential unobserved heterogeneity,a series of mixed logit models were *** explore and address potential temporal instability of crash-related risk factors,the likelihood ratio test was *** indicated that night crashes,crashes outside urban areas as well as crashes involving bicycles or powered-two-wheelers are associated with higher injury severity of children and ***,crashes involving pedestrians are associated with lower injury severity than head-on collisions and run-off-road collisions with fixed *** and sideswipe crashes also result in lower injury *** likelihood ratio test indicated that crash-related factors are instable when comparing the models utilizing data before and after 2010 *** study contributes to the current knowledge in the field,as to the best of our knowledge this is the first study that addresses unobserved heterogeneity when analyzing child and adolescent injury ***,the findings of this study provide useful insights and could assist in unveiling crash risk factors and prioritize programs and measures to promote road safety of children and adolescents.

关键词： Traffic engineering Traffic crash Injury severity Children Adolescents Unobserved heterogeneity

In vitro corrosion behaviour of phenolic coated nickel–titanium surfaces

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Biosurface and Biotribology 2020年第1期6卷 25-30页

作者： Simon Longela athanasios Chatzitakis IRC Tz P.O.Box 106048Dar es SalaamTanzania Department of Chemistry Centre for Materials Science and NanotechnologyUniversity of OsloFERMiOGaustadalléen 21NO-0349 OsloNorway

The biocompatibility of implantable nickel-titanium biomaterials relies on the quality of their *** this study,nickel-titanium surfaces are coated with phenolic thin films of tannic acid and pyrogallol with the purpose of studying their corrosion resistance in physiological *** tests are performed:the open-circuit potential test,potentiodynamic polarisation and potentiostatic electrochemical impedance *** measurements are scrutinised in order to gain knowledge concerning the kinetics of the cathodic and anodic reactions,while the open-circuit potentials and impedance spectroscopy help to study the electrolyte-surficial *** is found that coating nitinol with polyphenols results in the depletion of the native oxide layer and thus a decrease of corrosion *** treated nitinol surfaces(with a corrosion rate of 0.119 mm/year)are half as electrochemically corrosion resistive as tannic acid-coated ***,it is proposed that tannic treated nitinol would be a better option if implanted on biomaterial surfaces.

关键词： spectroscopy titanium phenolic

Review:Partial discharge diagnostics in wind turbine insulation

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Journal of Zhejiang University-Science C(Computers and Electronics) 2011年第6期12卷 515-522页

作者： Michael G.DANIKAS athanasios KARLIS Power Systems Lab Department of Electrical and Computer Engineering Democritus University of Thrace Electrical Machines Lab Department of Electrical and Computer Engineering Democritus University of Thrace

The purpose of this paper is to review work undertaken on partial discharges and their influence on the insulation of wind turbines. No matter whether partial discharges can be considered as the main cause of deterioration of the insulation material, the initial cause of failure or not but an indication of the material degradation, there is no doubt that they are intimately linked to the aging of machine insulation. Material degradation can be detected by non-destructive techniques (e.g., partial discharge measurements, change of tan δ) or by destructive techniques, such as by cutting small pieces of the insulating material and by putting them under the scrutiny of the scanning electron microscope (SEM). Wind generators are a modern subject of research, especially in view of the growing demands of electric energy worldwide and the problems facing the environment all over the globe. Wind turbines are a novel field of research regarding partial discharge diagnostics since they are subjected to a variety of aging factors, which are different from conventional turbines. In this respect, particular attention should be paid to the multi-factor stressing of insulation and their consequences on the partial discharges.

关键词： Partial discharges Rotating machine insulation Wind turbines