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Materials Sciences and Applications 2018年第11期9卷 873-882页

作者： Dimitrios I. Zagk.iveris georgios k. triantafyllidis Department of Chemical Engineering Aristotle University of Thessaloniki Thessaloniki Greece

Boriding of the Ti-Al intermetallic GE48-2-2 at 1273 k.for 10 hours was performed. In order to ensure that no any serious alteration occurred in the substrate, it was previously examined with X-Ray Diffractometry (XRD), after it has undergone an annealing process at the temperature of boronizing. Subsequently, we examined the coating with XRD and Scanning Electron Microscopy, in order to characterize its structure and morphology. A dense TiΒ2 layer, 10 - 15 μm thick. was formed, but also Cr2B3 and NbN, BN and some Ti-Al phases were detected. Efforts were undertak.n to focus on influence of the substrate modification, towards the quality of the coating.

关键词： Titanium Aluminide Boriding Titanium Boride Substrate Modification Phase Analysis X-Ray Diffraction

Natural Aging Effects on the Solutionizing Heat Treatment Process of the A6060 Al Alloy As-Cast Billets for Profile Production

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Materials Sciences and Applications 2015年第2期6卷 111-116页

作者： georgios k. triantafyllidis Natalyia V. Puk.alsk. Dimitrios I. Zagk.iveris Department of Chemical Engineering Aristotle University Thessaloniki Greece

Recently results were presented for an R & D program for handling the as-cast billets of an Al-Si-Mg A6060 Al alloy at the solutionizing heat treatment temperature. A reduction in the solutionizing temperature of the as-cast billets from 585℃ to 540℃ was found. This leads to substantial energy savings without lowering the quality of the final commercial Al profiles. The alloy was treated from the microstructural point of view as an Aluminum Metal-Matrix Composite (Al-MMC). Strengthening of the Al matrix grains during the process was quantified and measured by micro-Vick.rs hardness testing. A possible application of this is to apply the suggested lower temperature solutionizing process to billets stock.iled in the factory for some months. The alloy undergoes natural aging, a physical process at ambient temperature that alters its microstructural features. Does this aging affect the quality of the lower temperature solutionizing treated profiles? The effect of the natural aging by micro-Vick.rs hardness testing on some of the same samples of our original work.stock.iled in our lab for 10 months was investigated. We applied, further, the Image-Pro Plus image processing software on them in an effort to collect microstructural data and compared them to values tak.n 10 months earlier. Also we tried an interconnection between the two experimental processes treating the alloy as an Al-MMC.

关键词： A6060 Al Alloy Solutionizing Natural Aging Image Processing

Residual Stresses and Micro-Hardness Testing in Evaluating the Heat Affected Zone’s Width of Ferritic Ductile Iron Arc Welds

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Materials Sciences and Applications 2016年第1期7卷 73-82页

作者： georgios k. triantafyllidis Dimitrios I. Zagliveris Dionysios L. k.lioulis Christos S. Tsiompanis Titos N. Pasparak.s Athanasios P. Gredis Melina L. Sfantou Ioannis E. Giouvanak.s Department of Chemical Engineering Aristotle University Thessaloniki Greece

Shielded Metal Arc Welding (SMAW) in Ductile Irons (DI) is often required by foundries for practical manufacturing reasons. The mechanical properties of the welded structures are strongly dependent on their HAZ’s width. A model based on the behaviour of the ferritic matrix of high-Si DIs in order to mak. an approach in measuring their HAZ’s width is developed in this study. A series of thermal treatments on 3.35 and 3.75 wt% Si as-cast DIs and spot SMAWs is applied on these materials. The applied SMAWs are done on non-preheated and preheated samples (150℃ - 300℃). For welding we modify the amperage (100 - 140A). The micro-hardness Vick.rs changes in the ferrite of the as-cast samples and inside the HAZ of the welded ones can be attributed to the existence of residual stresses (RS) in the ferritic matrix and assist in estimating the HAZ’s width.

关键词： Welds Heat Affected Zone Residual Stresses Micro-Hardness Vick.rs Heat Affected Zone’s Width

Mechanisms of shoulder trauma: Current concepts

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World Journal of Orthopedics 2024年第1期15卷 11-21页

作者： k.nstantinos Mastrantonak.s Athanasios k.rvountzis Christos k.Yiannak.poulos georgios k.linterak.s Department of Orthopedic General Hospital of RethymnonRethymnon 73100CreteGreece 1^(st)Orthopedic Department Naval Hospital of AthensAthens 11521Greece Department of Orthopaedic Surgery National and Kapodistrian University of AthensAthens 11527Greece

Acute traumatic injuries to the glenohumeral articulation are *** types of injuries depend on age,muscle strength,bone density,and biomechanics of the traumatic *** the different mechanisms of trauma and how they affect the functional anatomical structures of the shoulder joint is crucial for the treatment of these ***,when clinicians have k.owledge of these mechanisms they can accurately diagnose and treat shoulder pathology and predict distinct injury ***,we have described the fundamentals of the mechanisms of injury of the glenohumeral dislocation,dislocation with fracture of the humeral head,and the proximal humerus *** have focused on common injury mechanisms and the correlation with radiological *** and laboratory findings of distinct types of injury were also discussed.

关键词： Mechanism Hill-Sachs Shoulder dislocation Proximal humerus fracture Shoulder biomechanics

On the connection between the solutions to the Dirac and Weyl equations and the corresponding electromagnetic four-potentials

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Communications in Theoretical Physics 2020年第4期72卷 52-63页

作者： Aristides I k.chriniotis Christos A Tsonos k.nstantinos k.Delibasis georgios N Tsigaridas Department of Physics University of ThessalyGR 35100 LamiaGreece Department of Computer Science and Biomedical Informatics University of ThessalyGR-35100 LamiaGreece Department of Physics School of Applied Mathematical and Physical SciencesNational Technical University of AthensGR-15780 Zografou AthensGreece

In this work.we study in detail the connection between the solutions to the Dirac and Weyl equations and the associated electromagnetic ***,it is proven that all solutions to the Weyl equation are degenerate,in the sense that they correspond to an infinite number of electromagnetic *** far as the solutions to the Dirac equation are concerned,it is shown that they can be classified into two *** elements of the first class correspond to one and only one four-potential,and are called non-degenerate Dirac *** the other hand,the elements of the second class correspond to an infinite number of four-potentials,and are called degenerate Dirac ***,it is proven that at least two of these fourpotentials are gauge-inequivalent,corresponding to different electromagnetic *** order to illustrate this particularly important result we have studied the degenerate solutions to the forcefree Dirac equation and shown that they correspond to massless *** have also provided explicit examples regarding solutions to the force-free Weyl equation and the Weyl equation for a constant magnetic *** all cases we have calculated the infinite number of different electromagnetic fields corresponding to these ***,we have discussed potential applications of our results in cosmology,materials science and nanoelectronics.

关键词： Dirac equation Weyl equation degenerate solutions electromagnetic four-potentials electromagnetic fields massless particles

Acute chylous peritonitis due to acute pancreatitis

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World Journal of Gastroenterology 2012年第16期18卷 1987-1990页

作者： georgios k.Georgiou Haralampos Harissis Michalis Mitsis Haralampos Batsis Michalis Fatouros Department of Surgery University Hospital of Ioannina45500 IoanninaGreece

We report a case of acute chylous ascites formation presenting as peritonitis(acute chylous peritonitis) in a patient suffering from acute pancreatitis due to hypertriglyceridemia and alcohol *** development of chylous ascites is usually a chronic process mostly involving malignancy,trauma or surgery,and symptoms arise as a result of progressive abdominal ***,when accumulation of "chyle" occurs rapidly,the patient may present with signs of *** diagnosis is difficult since the clinical picture usually suggests hollow organ perforation,appendicitis or visceral *** than 100 cases of acute chylous peritonitis have been *** is a rare cause of chyloperitoneum and in almost all of the cases chylous ascites is discovered some days(or even week.) after the onset of symptoms of *** is the second case in the literature where the patient presented with acute chylous peritonitis due to acute pancreatitis,and the presence of chyle within the abdominal cavity was discovered simultaneously with the establishment of the diagnosis of *** patient underwent an exploratory laparotomy for suspected perforated duodenal ulcer,since,due to hypertriglyceridemia,serum amylase values appeared within the normal ***,abdominal computed tomography imaging was not diagnostic for *** abdominal lavage and drainage,the patient was successfully treated with total parenteral nutrition and octreotide.

关键词： Chylous ascites Chyloperitoneum Chyle Peritonitis Pancreatitis

Radiological simultaneous portohepatic vein embolization(RASPE)and major hepatectomy with hepatocellular carcinoma(HCC)

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Hepatobiliary Surgery and Nutrition 2021年第2期10卷 267-269页

作者： georgios k.Glantzounis Anastasia k.rampa Dimitra Peristeri HPB Unit Department of SurgeryUniversity Hospital of Ioannina and School of MedicineUniversity of IoanninaIoanninaGreece

Radiological simultaneous portohepatic vein embolization(RASPE)is a relatively new technique,which aims to rapidly increase the future liver remnant(FLR)in patients with very small FLR in order to undergo major hepate... 详细信息

关键词： hepatic hepatectomy simultaneous

Anion effect on Li/Na/k.hybrid electrolytes for Graphite//NCA(LiNi_(0.8)Co_(0.15)Al_(0.05)O_(2))Li-ion batteries

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Journal of Energy Chemistry 2022年第1期31卷 451-462,I0012页

作者： Aiman Jrondi georgios Nik.foridis Meriem Anouti Laboratoire PCM2E Universite de ToursFaculte des sciences et technologiePare de Grandmont37200 ToursFrance LE STUDIUM Institute for Advanced Studies 45000 OrleansFrance

The electrolyte is an essential component of a battery system since it is responsible for the conduction of ions between the *** the quest for cheaper alternatives to common organic electrolytes for lithium-ion batteries(LIB),we formulated hybrid electrolytes comprising a mixture of Na,k.and Li alk.line salts with ethylene carbonate(EC),ethyl methyl carbonate(EMC),and lithium hexafluorophosphate(LiPF_(6)),giving a total salt concentration of 1.5 M;we determined their physicochemical properties and investigated their electrochemical behavior on a nick.l cobalt aluminum oxide(NCA)cathode and graphite(Gr)*** electrolytes demonstrated a melting transition peak.T_(m)).eutectic behavior,and ionic conductivities(-13 mS cm^(-1))close to those of a commercial LIB electrolyte(SE,EC/EMC+1 M LiPF_(6))and activation energies of ca.3 k. mol^(-1).The half-cell coin cells revealed high coulombic efficiency(99%),specific capacity(175 mAh g^(-1) at C/10),and capacity retention(92% for NaCF_(3)SO_(3))for the NCA cathode and a moderate performance(coulombic efficiency of 98%for 20 cycles)on the graphite anode after the formation of the SEI *** hybrid electrolytes were cycled at 25℃ in a Gr//NCA cell yielding specific capacities of ca.225 mAh g^(-1) at a C/5 rate,corroborating that the anion plays a k.y role and highlighting their potential for energy storage applications.

关键词： Hybrid electrolyte Alk.li salts NCA//Li cell Li-ion battery

On the refracted patterns produced by liquid vortices

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Acta Mechanica Sinica 2007年第1期23卷 11-15页

作者： Yasser Aboelk.ssem georgios H.Vatistas McGill University MontrealQCH3A-2K6Canada Concordia University MontrealQCH3G 1M8Canada

A theoretical analysis of the refracted shadows produced by steady and time-decaying liquid vortices under uniform illumination from above is given in this article. An expression for the induced shadow intensity is derived and found to be a function of the vortex＇s free surface profile, i.e., function of the static pressure distribution. The patterns for different focusing depth are given and compared with previous visualization results from the literature. The phenomenon is examined and illustrated as a bench mark.case by using both steady and time-decaying algebraic vortex models. However, this study can be extended to check.the feasibility of recovering the main flow properties by analyzing the luminous image intensity of the refracted patterns. The present analysis is valid only when the swirl velocity is order of magnitude higher than the meridional flow components and the vorticity is concentrated within the core region and of intense conditions.

关键词： Fluid dynamics - Vortices - Dark.shadows Intensity - Time decay

Mechanical behavior of colonic anastomosis in experimental settings as a measure of wound repair and tissue integrity

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World Journal of Gastroenterology 2006年第35期12卷 5668-5673页

作者： k.nstantinos A Ek.ek.zoglou georgios C Zografos Stavros k.k.urk.ulis Ismene A Dontas Panagiotis k.Giannopoulos Κaterina A Marinou Maria V Poulak.u Despina N Perrea Laboratory of Experimental Sur- gery and Surgical Research "NS Christeas" University of Athens Medical School Athens Greece 1st Univer- sity Department of General Surgery Athens School of Medicine Hippocration Hospital Athens Greece Laboratory of Testing and Materials De- partment of Mechanics National Technical University of Athens Greece BVMS MVM Laboratory of Experimen- tal Surgery and Surgical Research "NS Christeas" University of Athens Medical School Athens Greece and Greek Ministry of Rural Development and Food General Directorate of Veterinary Services

AIM: To determine the mechanical properties of anasto- motic colonic tissue in experimental settings and there- fore give a measure of wound healing. METHODS: Thirty-six male Wistar rats were used as ex- perimental models of anastomotic tissue integrity. On the 5th post-operative day, the tensile strength was measured by application of an axial force, providing a quantitative measure of anastomotic dehiscence and leak.ge. RESULTS: Diagrams of the load as a function of the time [P = P (t)] and of the displacement also as a func- tion of time [Δs = Δs (t)] were recorded for each test, permitting the design of the load versus the displace- ment diagram and thus providing significant data about the critical values of anastomotic failure. Quantitative data were obtained concerning the anastomotic strength of both control specimens (healthy rats), as well as spec- imens from non-healthy rats for comparison. CONCLUSION: This experimental model provides an excellent method of measuring anastomotic strength. Despite the relative small number of specimens used, this method provides an accurate way of measuring wound repair. More experimental measurements need to be performed to correlate emerging tensile strength val-ues to anastomotic failure.

关键词： Mechanical behavior Failure load Colon Anastomosis Wound healing