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Institution

University of Patras

EducationPátrai, Greece
About: University of Patras is a education organization based out in Pátrai, Greece. It is known for research contribution in the topics: Population & Catalysis. The organization has 13372 authors who have published 31263 publications receiving 677159 citations. The organization is also known as: Panepistímio Patrón.


Papers
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Journal ArticleDOI
TL;DR: In this paper, the effects of shot peening process parameters on the treated material were investigated by using a three dimensional numerical model, comprising the target plate and a number of shot impacts; their number is defined as the minimum required for a realistic simulation and minimum computational cost.
Abstract: An investigation of the effects of controlled shot peening (CSP) process parameters on the treated material is presented. For this purpose, a three dimensional numerical model is developed, comprising the target plate and a number of shot impacts; their number is defined as the minimum required for a realistic simulation and minimum computational cost. The numerical model is verified by comparing the predicted residual stress (RS) fields to experimental. A parametric study of the shot velocity and impinging angle on the CSP products is performed for 4 shot types, i.e. S110, S230, S330 and S550. The main advantages of the present numerical model are: a) the relatively high number of shots introduced in the simulation compared to other publications that use only one shot, b) the number of shots dependency on the desired coverage, c) the thorough selection of numerical parameters, d) the high-strain rate material behaviour used for the target plate, e) the capability to calculate CSP effects on the target plate as function of coverage, f) the computed data which include RS field, surface roughness, cold work and geometrical stress concentration factor (Kt) and finally g) the computed results which are validated by experimental measurements.

144 citations

Journal ArticleDOI
TL;DR: In this article, it was shown conclusively that the mechanism of metal-support interaction in the system IrO2-TiO2 is identical to that of the electrochem.

144 citations

Proceedings ArticleDOI
01 Sep 2007
TL;DR: In this article, the authors present a novel current pulsation smoothing parallel active filter (CPS-PAF) which is independent from the inverter topology and his operation mode.
Abstract: The newest technology on decentralised grid-connected PV systems is the "AC-PV Module", which is characterised by a number of clear advantages over conventional large PV systems. Single stage topologies seem to be a rather attractive solution, for these applications, since in generally they are characterised by high efficiency, low cost and simple structure with high reliability due to reduced components count. On the other hand in single-phase AC-PV Module inverters, the power that is transferred to the power network has a large amount of power pulsation at twice line frequency. So a large ripple of voltage and current appears at the PV module output. Taking into account that there is a close correspondence between the power that flows from a PV module and the point of operation, this fact leads to reduced PV power generation. In order to overcome this defect, this paper presents a novel current pulsation smoothing parallel active filter (CPS-PAF) which is independent from the inverter topology and his operation mode. Purpose of the proposed CPS-PAF is the elimination of the low frequency PV current ripple. So the PV module can be operated close enough to the maximum power point and consequently the PV generated electricity power is maximised. The CPS-PAF conception, control and effectiveness are validated by PSpice simulation and experimental results accomplished on a laboratory prototype.

144 citations

Journal ArticleDOI
14 May 2020-Polymers
TL;DR: The production of bio-based polymers from renewable sources and microbial synthesis are scalable, facile, and pose a minimal impact on the environment compared to chemical synthesis methods that rely on alkali and acid treatment or co-polymer blending.
Abstract: Agro-wastes are derived from diverse sources including grape pomace, tomato pomace, pineapple, orange, and lemon peels, sugarcane bagasse, rice husks, wheat straw, and palm oil fibers, among other affordable and commonly available materials. The carbon-rich precursors are used in the production bio-based polymers through microbial, biopolymer blending, and chemical methods. The Food and Agriculture Organization (FAO) estimates that 20–30% of fruits and vegetables are discarded as waste during post-harvest handling. The development of bio-based polymers is essential, considering the scale of global environmental pollution that is directly linked to the production of synthetic plastics such as polypropylene (PP) and polyethylene (PET). Globally, 400 million tons of synthetic plastics are produced each year, and less than 9% are recycled. The optical, mechanical, and chemical properties such as ultraviolet (UV) absorbance, tensile strength, and water permeability are influenced by the synthetic route. The production of bio-based polymers from renewable sources and microbial synthesis are scalable, facile, and pose a minimal impact on the environment compared to chemical synthesis methods that rely on alkali and acid treatment or co-polymer blending. Despite the development of advanced synthetic methods and the application of biofilms in smart/intelligent food packaging, construction, exclusion nets, and medicine, commercial production is limited by cost, the economics of production, useful life, and biodegradation concerns, and the availability of adequate agro-wastes. New and cost-effective production techniques are critical to facilitate the commercial production of bio-based polymers and the replacement of synthetic polymers.

144 citations

Book ChapterDOI
01 Jan 2006
TL;DR: This work presents TMG, a research and teaching toolbox for the generation of sparse tdms from text collections and for the incremental modification of these tdms by means of additions or deletions, written entirely in MATLAB.
Abstract: A wide range of computational kernels in data mining and information retrieval from text collections involve techniques from linear algebra. These kernels typically operate on data that are presented in the form of large sparse term-document matrices (tdm). We present TMG, a research and teaching toolbox for the generation of sparse tdms from text collections and for the incremental modification of these tdms by means of additions or deletions. The toolbox is written entirely in MATLAB, a popular problem-solving environment that is powerful in computational linear algebra, in order to streamline document preprocessing and prototyping of algorithms for information retrieval. Several design issues that concern the use of MATLAB sparse infrastructure and data structures are addressed. We illustrate the use of the tool in numerical explorations of the effect of stemming and different term-weighting policies on the performance of querying and clustering tasks.

143 citations


Authors

Showing all 13529 results

NameH-indexPapersCitations
Thomas J. Meyer120107868519
Thoralf M. Sundt11275555708
Chihaya Adachi11290861403
Eleftherios P. Diamandis110106452654
Roland Siegwart105115451473
T. Geralis9980852221
Spyros N. Pandis9737751660
Michael Tsapatsis7737520051
George K. Karagiannidis7665324066
Eleftherios Mylonakis7544821413
Matthias Mörgelin7533218711
Constantinos C. Stoumpos7519427991
Raymond Alexanian7521121923
Mark J. Ablowitz7437427715
John Lygeros7366721508
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202395
2022250
20211,738
20201,672
20191,469
20181,443