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Predicting uniaxial compressive strength of serpentinites through physical,dynamic and mechanical properties using neural networks

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Journal of Rock Mechanics and Geotechnical Engineering 2021年第1期13卷 167-175页

作者： vassilios C.Moussas Konstantinos Diamantis Department of Civil Engineering School of EngineeringUniversity of West AtticaCampus 1Ag.Spiridona Str.EgaleoAthens12243Greece

The uniaxial compressive strength(UCS)of intact rock is one of the most important parameters required and determined for rock mechanics studies in engineering *** limitations and difficulty of conducting tests on rocks,specifically on thinly bedded,highly fractured,highly porous and weak rocks,as well as the fact that these tests are destructive,expensive and time-consuming,lead to development of soft computing-based *** of artificial neural networks(ANNs)for predicting UCS has become an attractive alternative for geotechnical engineering *** this study,an ANN was designed with the aim of indirectly predicting UCS through the serpentinization percentage,and physical,dynamic and mechanical characteristics of *** this purpose,data obtained in earlier experimental work from central Greece were *** ANN-based results were compared with the experimental ones and those obtained from previous *** proposed ANN-based formula was found to be very efficient in predicting UCS values and the samples could be classified with simple physical,dynamic and mechanical tests,thus the expensive,difficult,time-consuming and destructive mechanical tests could be avoided.

关键词： Rock mechanic Serpentinites Uniaxial compressive strength(UCS) Artificial neural networks(ANNs) Physical,dynamic and mechanical properties

Global transplantation:Lessons from organ transplantation organizations worldwide

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World Journal of Transplantation 2025年第1期15卷 44-56页

作者： Solonas Symeou Eleni Avramidou vassilios Papalois Georgios Tsoulfas Medical School University of IoanninaIoannina 45110Greece Department of Transplantation Surgery Center for Research and Innovation in Solid Organ TransplantationSchool of MedicineAristotle University of ThessalonikiThessaloniki 54642Greece Imperial College Renal and Transplant Centre Imperial College Healthcare NHS TrustHammersmith HospitalLondon W120HSUnited Kingdom Department of Surgery and Cancer Imperial College LondonLondon SW72AZUnited Kingdom

Although national transplant organizations share common visions and goals,the creation of a unified global organization remains *** in ethnicity,culture,religion,and education shape local practices and infrastructure,making the establishment of a single global entity *** with these social disparities aside,logistical factors such as time and distance between organ procurement and transplantation sites pose significant *** technological advancements have extended organ preservation times,they have yet to support the demands of transcontinental transplantations *** review presents a comparative analysis of the structures,operational frameworks,policies,and legislation governing various transplant organizations around the *** differences pertain to the administration of these organizations,trends in organ donation,and organ allocation policies,which reflect the financial,cultural,and religious diversity across different *** a global transplant organization may be out of reach,agreeing on best practices for the benefit of patients is essential.

关键词： Organ transplantation National transplant organizations Organ donation Global transplantation Transplant systems

Nacelle intake flow separation reduction at cruise condition using active flow control

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Propulsion and Power Research 2022年第3期11卷 337-352页

作者： Vinayak Ramachandran Nambiar vassilios Pachidis Centre for Propulsion Engineering Cranfield UniversityBedfordMK430ALUK

Turbofan engine intakes are designed to provide separation-free flow at the fan faceover a wide range of operating conditions. But at some off-design conditions, like at high flightspeeds and high angles of attack (AoA), the aero engine intake may encounter flow *** boundary layer separation inside the nacelle inlet of an aircraft engine can lead to a largenumber of undesirable outcomes like reduction in fan efficiency, engine stall and high levels ofstress on the fan blades. Active flow control is a promising solution to reduce inlet boundarylayer separation and the associated fan-face flow distortion at such off-design conditions. Byblowing pressurized air into the intake near the separation point, the boundary layer is ener-gized and separation can be controlled. This study investigates the applicability of lip blowing,an active flow control technique, to control intake separation and flow distortion at the ***, intake separation was triggered in a 3D CFD model based on the NASA CommonResearch Model (CRM) using high AoA cases at cruise condition (Mach number 0.85, Massflow capture ratio w0.7) and the features of separated flow were analyzed. Thereafter, activeflow control was introduce to the intake in the form of two types of lip blowing, direct andpitched blowing. The efficacy of lip blowing at achieving separation control in an ultra highbypass ratio turbofan engine intake has been established through this study. The present paperalso examines the significance of blowing parameters like the type of blowing, blowing pres-sure ratio, and blowing slot dimension, at different angles of attack to identify the critical con-trol parameters. Our research successfully establishes proof of concept by demonstrating the feasibility of using lip blowing for separation control in aero-intakes, via numerical ***, this study also provides crucial insights regarding the important variables to beconsidered for future experimental studies

关键词： Ultra high bypass ratio turbofan engine NASA Common Research Model Reynolds-averaged Navier-Stokes(RANS) Computational fluid dynamics(CFD) ANSYS Fluent Intake flow separation Active flow control Lip blowing

A non-lithographic plasma nanoassembly technology for polymeric nanodot and silicon nanopillar fabrication

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Frontiers of Chemical Science and Engineering 2019年第3期13卷 475-484页

作者： Athanasios Smyrnakis Angelos Zeniou Kamil Awsiuk vassilios Constantoudis Evangelos Gogolides Institute of Nanoscience & Nanotechnology NCSR “Demokritos”Ag. Paraskevi15341 AtticaGreece Department of Physics University of Patras26504 PatrasGreece M. Smoluchowski Institute of Physics Jagiellonian University30-348 KrakowPoland

In this work, we present plasma etching alone as a directed assembly method to both create the nanodot pattern on an etched polymeric (PMMA) film and transfer it to a silicon substrate for the fabrication of silicon nanopillars or cone-like nanostructuring. By using a shield to control sputtering from inside the plasma reactor, the size and shape of the resulting nanodots can be better controlled by varying plasma parameters as the bias power. The effect of the shield on inhibitor deposition on the etched surfaces was investigated by time-of-flight secondary ion mass spectroscopy (ToF-SIMS) measurements. The fabrication of quasi-ordered PMMA nanodots of a diameter of 25 nm and period of 54 nm is demonstrated. Pattern transfer to the silicon substrate using the same plasma reactor was performed in two ways:(a) a mixed fluorine-fluorocarbon-oxygen nanoscale etch plasma process was employed to fabricate silicon nanopillars with a diameter of 25 nm and an aspect ratio of 5.6, which show the same periodicity as the nanodot pattern, and (b) high etch rate cryogenic plasma process was used for pattern transfer. The result is the nanostructuring of Si by high aspect ratio nanotip or nanocone-like features that show excellent antireflective properties.

关键词： plasma nanoassembly etching nanodots nanopillars nanofabrication

Modified TiO_(2) based photocatalysts for improved air and health quality

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Journal of Materiomics 2017年第1期3卷 3-16页

作者： vassilios Binas Danae Venieri Dimitrios Kotzias George Kiriakidis Institute of Electronic Structure and Laser Foundation for Research and Technology HellasP.O.Box 152771110 HeraklionGreece Crete Center for Quantum Complexity and Nanotechnology Department of PhysicsUniversity of CreteP.O.Box 220871003 HeraklionGreece School of Environmental Engineering Technical University of CreteGR-73100 ChaniaGreece Joint Research Centre Institute for Health and Consumer ProtectionVia Germania 29Ispra21027 VAItaly

Photocatalysis with modified titania is a promising approach to improve both air and health *** titania with novel photocatalytic properties under indoor light irradiation leads to smart coatings,which are benchmark materials suitable for their indoor *** is generally accepted that the photocatalytic activity is affected by the light absorption,charge creation/recombination rate and surface *** this contribution we focus on modified TiO_(2) as catalyst in heterogeneous photocatalytic processes and address the efficiency of TiO_(2)-based building and construction materials on the removal of environmental pollutants indoors and *** also present data on the presence of eventually formed,toxicologically relevant and harmful by-products as the result of the photo-induced degradation of pollutants in an effort for better evaluation of induced risks for human health from the application of TiO_(2) modified ***,we present recent results on the disinfection performance of these material and the inactivation of severe pathogens contained in water and indoor air environments.

关键词： Photocatalysis Indoor air quality Visible light photocatalyst Disinfection

Photocatalytic oxidation of gaseous benzene,toluene and xylene under UV and visible irradiation over Mn-doped TiO_(2)nanoparticles

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Journal of Materiomics 2019年第1期5卷 56-65页

作者： vassilios Binas Vassilis Stefanopoulos George Kiriakidis Panos Papagiannakopoulos Laboratory of Photochemistry and Kinetics Department of ChemistryUniversity of Crete71003HeraklionCreteGreece Institute of Electronic Structure and Laser(IESL) FORTHP.O.Box 1527Vasilika VoutonGR-71110HeraklionGreece Crete Center for Quantum Complexity and Nanotechnology Department of PhysicsUniversity of Crete71003HeraklionGreece

The photocatalytic oxidation of gaseous benzene,toluene and xylene(BTX)over un-doped,0.1 and 1 wt%Mn-TiO_(2)nanoparticles under ultraviolet and visible irradiation was studied in atmosphere of synthetic air or inert *** photocatalytic decomposition efficiency and the oxidation products were determined using a Static Photochemical Reactor coupled with FTIR *** underwent efficient decomposition over Mn-TiO_(2)photocatalysts under UV irradiation,more with oxygen presence and less without *** important toluene and xylene went substantial decomposition over 0.1 mol%Mn-TiO_(2)under visible irradiation with oxygen *** main final oxidation products in the UV photocatalysis of BTX were CO_(2),CO and H2O,with CO_(2) and CO yields 4 and 2 *** conversion percentage of benzene,toluene,and xylene to CO_(2) were 63.6%,56.4%,51.8%,and to CO 29%,26.5%,23.2%,*** the visible photocatalysis of toluene and xylene the yields of CO were *** of carbon containing deposits on TiO_(2)surfaces was observed after extensive UV photocatalysis of toluene and xylene,and such by-products surface coverage may reduce the photocatalytic activity of TiO_(2)*** aspects of the photocatalytic mechanism were examined.

关键词： Mn-doped TiO_(2) Visible Light photocatalysis Photodegradation of benzene Toluene Xylene Indoors air pollution

Impact of polyethylene glycol 400/propylene glycol/hydroxypropyl-guar and 0.1%sodium hyaluronate on postoperative discomfort following cataract extraction surgery:a comparative study

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Eye and Vision 2017年第1期4卷 59-65页

作者： Georgios Labiris Panagiota Ntonti Haris Sideroudi vassilios Kozobolis Department of Ophthalmology University Hospital of Alexandroupolis68100 DraganaAlexandroupolisGreece Eye Institute of Thrace AlexandroupolisGreece

Background:Universal postoperative guidelines for cataract extraction surgery are yet to be *** tears are gaining popularity as an additional integral component of the postoperative *** primary objective of this study was to explore the impact of two prevalent artificial tear preparations on postoperative discomfort following cataract extraction ***:A total of 180 patients that underwent cataract extraction surgery were randomly divided into three groups according to their postoperative regime:a)Study group 1(SG1)received a fixed combination of tobramycin and dexamethasone(FCTD)quid for 3 weeks and,additionally polyethylene glycol 400/propylene glycol/hydroxypropyl-guar quid,for 6 weeks,b)Study group 2(SG2)received FCTD quid for 3 weeks and,additionally 0.1%sodium hyaluronate provided in the COMOD^(®)device quid,for 6 weeks,and,c)Control Group(CG)received only FCTD quid for 3 *** following indexes were evaluated at three postoperative checkpoints:1)Subjective discomfort index(SDI)derived from four direct 10-scale Likert-type questions that were addressed to the patient and pertained to:a)foreign body sensation(FBS),b)blinking discomfort(BD),c)stinging sensation(SS),d)tearing sensation(TS),2)Tear break-up time(TBUT),3)Central corneal thickness(CCT)and,4)Central Corneal Sensitivity(CCS).Results:Both groups showed increased CCT values at the first examination point and reduced CCS values at all examination ***,both SGs had better TBUT times at all examination points compared to CG(CG:8.86±1.08,SG1:9.59±1.45,CG2:9.45±1.33,p<0.05).BD was significantly better in both SGs only at the 1^(st) week of examination,while SDI values were better until the 3^(rd) week and only borderline better at 6^(th) ***,no significant differences were detected between SGs,regarding all parameters,at all examination ***:Polyethylene glycol 400/propylene glycol/hydroxypropyl-guar and 0.1%sodium hyaluronate provided

关键词： Cataract Postoperative regimen Artificial tears Surface discomfort index Systane Hylocomod

A systematic review of teleophthalmological studies in Europe

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International Journal of Ophthalmology(English edition) 2018年第2期11卷 314-325页

作者： Georgios Labiris Eirini-Kanella Panagiotopoulou vassilios P.Kozoboli Department of Ophthalmology University Hospital of AlexandroupolisDraganaAlexandroupolis 68 100Greece Eye Institute of Thrace Alexandroupolis 68100Greece

A systematic review of the recent literature regarding a series of ocular diseases involved in European telemedicine projects was performed based on the Pub Med, Google Scholar and Springer databases in June 2017. Literature review returned 44 eligible studies; among them, emergency ophthalmology, diabetic retinopathy, glaucoma, age-related macular disease, cataract and retinopathy of prematurity. The majority of studies indicate teleophthalmology as a valid, reliable and cost-efficient method for care-provision in ophthalmology patients which delivers comparable outcomes to the traditional examination methods.

关键词： teleophthalmology telemedicine Europe glaucoma cataract diabetic retinopathy

COVID-19 pandemic:Building organisational flexibility to scale transplant programs

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World Journal of Transplantation 2020年第10期10卷 277-282页

作者： Jeevan Prakash Gopal vassilios E Papalois Imperial College Renal and Transplant Center Hammersmith HospitalImperial College Healthcare NHS TrustLondon W120HSUnited Kingdom Imperial College Renal and Transplant Center Department of Surgery and CancerHammersmith HospitalImperial College Healthcare NHS TrustLondon W120HSUnited Kingdom

The prevailing coronavirus disease 2019 pandemic has challenged our lives in an unprecedented *** pandemic has had a significant impact on transplantation *** logistics of travel restrictions,stretching of available resources,unclear risk of infection in immunosuppressed transplant recipients,and evolving guidelines on testing and transplantation are some of the factors that have unfavourably influenced transplant *** must begin to build organisational flexibility in order to restart transplantation so that we can be mindful stewards of organ donation and sincere advocates for our *** a culture of honesty and transparency(with patients,families,colleagues,societies,and authorities),keeping the channels of communication open,working in collaboration with others(at local,regional,national,and international levels),and not restarting without rethinking and appraising all elements of our practice,are the main underlying principles to increase the flexibility.

关键词： Organisational flexibility Clinical decision making COVID-19 Organ donation Care delivery Transplantation