Technical University Gheorghe Asachi
Iasi, Romania

The Gheorghe Asachi Technical University is a public university located in Iași, Romania. It has the oldest tradition in Romania in engineering education. Wikipedia.

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Radu C.-D.,Technical University Gheorghe Asachi | Parteni O.,Technical University Gheorghe Asachi | Ochiuz L.,Grigore T. Popa University of Medicine and Pharmacy
Journal of Controlled Release | Year: 2016

This paper presents data on the general properties and complexing ability of cyclodextrins and assessment methods (phase solubility, DSC tests and X-ray diffraction, FTIR spectra, analytical method). It focuses on the formation of drug deposits on the surface of a textile underlayer, using a cyclodextrin compound favoring the inclusion of a drug/active principle and its release onto the dermis of patients suffering from skin disorders, or for protection against insects. Moreover, it presents the kinetics, duration, diffusion flow and release media of the cyclodextrin drug for in vitro studies, as well as the release modeling of the active principle. The information focuses on therapies: antibacterial, anti-allergic, antifungal, chronic venous insufficiency, psoriasis and protection against insects. The pharmacodynamic agents/active ingredients used on cotton, woolen and synthetic textile fabrics are presented. © 2016 Elsevier B.V.

Axinte E.,Technical University Gheorghe Asachi
Materials and Design | Year: 2012

Metallic glasses, first discovered a half century ago, are currently among the most studied metallic materials. Available in sizes up to several centimeters, with many novel, applicable properties, metallic glasses have also been the focus of research advancing the understanding of liquids and of glasses in general.Metallic glasses (MGs), called also bulk metallic glasses (BMGs) (or glassy metals, amorphous metals, liquid metals) are considered to be the materials of the future. Due to their high strength, metallic glasses have a number of interesting applications, for example as coatings. Metallic glasses can also be corrosion resistant. Metallic glasses, and the crystalline materials derived from them, can have very good resistance to sliding and abrasive wear. Combined with their strength - and now, toughness - this makes them ideal candidates for bio-implants or military applications. Prestigious Journals such as " Nature Materials" , " Nature" frequently publish new findings on these unusual glass materials. Moreover Chinese and Asian scientists have also been showing an interest in the study of metallic glasses.This review paper is far from exhaustive, but tries to cover the areas of interest as it follows: a short history, the local structure of BMGs and the glass forming ability (GFA), BMGs' properties, the manufacturing and some applications of BMGs and finally, about the future of BMGs as valuable materials. © 2011 Elsevier Ltd.

Minea A.A.,Technical University Gheorghe Asachi
International Journal of Heat and Mass Transfer | Year: 2014

At this stage of nanofluids development, their thermal conductivity it is not yet known precisely and the judgment of their true potential is difficult. This fact was illustrated by analyzing their heat transfer performance for laminar fully developed forced convection in a tube with two zones: one adiabatic and one with uniform wall heat flux. Forced convective of a nanofluid that consists of water and Al2O3 in horizontal tubes has been studied numerically. Three different models from the literature are used to express the thermal conductivity in terms of particle loading and they led to different qualitative and quantitative results in a classical problem of replacement of a simple fluid (water) by a nanofluid in a given situation. In particular, the heat transfer coefficient of water-based Al2O 3 nanofluids is increased by 3.4-27.8% under fixed Reynolds number compared with that of pure water. Also, the enhancement of heat transfer coefficient is larger than that of the effective thermal conductivity at the same volume concentration. Moreover, the effect of uncertainties in modeling nanofluids properties was noticed. © 2013 Elsevier Ltd. All rights reserved.

Toma S.L.,Technical University Gheorghe Asachi
Surface and Coatings Technology | Year: 2013

In the arc spraying processes, velocity and temperature of the sprayed particles, which are in a close relationship with the drive jet velocity and temperature, influence the physical and mechanical properties of the coatings. This paper presents a comparative research of 30. T steel deposits, carried out by two spraying procedures: the classic wire arc spraying procedure plus a new one, which represents a combination between the classic wire arc spraying and the flame spraying procedure. The use of a new procedure allowed the increase of the drive jet temperature and the study of its effect created on 30. T deposits properties. The modelling of the arc spraying and the analysis with finite elements in a coupled field allowed the determination of the drive jet temperature variation and the fuel flow, necessary for the temperature to be maintained over 1000. K at spraying distance of 150. mm. The investigations carried out on 30. T steel coatings, obtained by this procedure, demonstrate that the spraying jet temperature increase determines the average growth of the coatings adherence over 18% for cylindrical surface and over 5% for flat surface. Also, these investigations demonstrate the decrease of the average porosity by over 22% for cylindrical surface and by over 17% for flat surface. © 2012 Elsevier B.V..

Axinte E.,Technical University Gheorghe Asachi
Materials and Design | Year: 2011

Glass products have applications in design engineering, and they can solve many special problems. These materials can work in situations in which plastics and metals would fail and need to be part of designer's repertoire. In some situations, by using these materials, some difficult problems would be solved. This paper contains a number of chapters as follows: a brief about ceramics family, a short history of glass, a brief about physics and the technology of glass fabrication, recently developed glasses with special destinations, testing methods and news about glass parts processing (grinding, waterjet processing, laser cutting, nanoimprint lithography, etc.). The last chapter of this review paper contain some strategic lines of glass usage in industry and estimations about the future of glass development. © 2010 Elsevier Ltd.

Chiriac G.,Technical University Gheorghe Asachi
Electric Power Systems Research | Year: 2012

This paper describes a thermal model of fast fuse suitable for power electronic circuits. This model can be used to analyse the thermal behaviour of the fuselink during steady-state conditions when different types of notches are applied. Results from mathematical models have been compared with those from 3D thermal models using software based on the finite element method and from experimental tests. The temperature values from thermal simulations and experimental data are very similar those coming from mathematical models. © 2012 Elsevier B.V. All rights reserved.

Minea A.A.,Technical University Gheorghe Asachi
International Journal of Heat and Mass Transfer | Year: 2013

In this paper, turbulent convective heat transfer in a two-dimensional microtube with 10 mm diameter and variable length with constant heating temperature was numerically investigated. The governing (continuity, momentum and energy) equations were solved using the finite volume method with the aid of SIMPLE algorithm on FLUENT commercial code. Water-Al2O3 nanofluids with different volume fractions ranged from 1% to 4% were used. This investigation covers Reynolds number in the range of 104-10 5. The results have shown that convective heat transfer coefficient for a nanofluid is enhanced than that of the base liquid. Wall heat transfer flux is increasing with the particle volume concentration and Reynolds number. Moreover, a study on microtube length influence on heat transfer was attempted and few correlations were established.© 2013 Elsevier Ltd. All rights reserved.

Nituca C.,Technical University Gheorghe Asachi
Electric Power Systems Research | Year: 2013

This paper describes a thermal model of electric contacts suitable for power circuits, especially for pantograph-catenary system used to supply the electric vehicles as tramways and trains. Because the contact pieces are made of different materials, the thermal model deals with two different thermal power loss using fractions of the total thermal power. The maximum contact heating and the heating distribution expressions have been established for both contact pieces. This model has been validated for an electric contact between a small pantograph and a copper disc with the aim to simulate the contact between the pantograph and the catenary. The model can be used to analyse the thermal behaviour of electric contacts made of different materials at different values of the electric current, contact force or ambient temperature, in steady-state conditions. © 2012 Elsevier B.V.

Plesca A.,Technical University Gheorghe Asachi
Electric Power Systems Research | Year: 2012

This paper describes a simplified thermal model of fast fuse suitable for power electronic circuits, especially for power rectifiers. This model has been validated with a single-phase rectifier and can be used to analyse the thermal behaviour of fast fuses during transient conditions. The procedure for achieving the simplified model is also presented. The parameters' model include all the necessary information about the fast fuse geometry, its components' materials and heat dissipation to the surrounding area. On the basis of this simplified model, the transient thermal behaviour of fast fuse can be estimated for complex power electronic circuit with accuracy and speed. © 2011 Elsevier B.V. All rights reserved.

Romanescu G.,Technical University Gheorghe Asachi
Quaternary International | Year: 2013

The study presents a brief review of the main evolutionary stages of the Danube deltaic area, according to the most recent discoveries in the field, as well as an emphasis on the new delimitating criteria for the hinterland in the ancient (7th century B.C.-5th century A.D.) and medieval times (14th-18th centuries A.D.) A cartographic delimitation model for the studied settlements' hinterlands was created. The Danube Delta is a dynamic interface between the geological history, the deltaic morphogenesis and the human occupation. The Danube Delta complex is one of the most important geo-political and cultural entities which can be described as a compound geographical unit that provides an exceptional biodiversity. Although this area has been intensely inhabited during the previous historical periods, underlined in the case of several ancient and medieval sources, only limited archaeological sites have been identified up to the present, and they are affected by the permanent extension and mobility of the Danube Delta. The Greek cities of Istros/Histria and Orgame/Argamum, colonies established by Miletus, which later continued their development as Roman cities, were located in the lagoonal region on the coast. The Roman fortification of Halmyris was situated on the Danube Delta's southern branch and the small bastion was located on the island called " Bisericuta" Two other medieval fortresses were identified; Heraclea, probably a Genovese fortress (present-day Enisala), and the Ottoman fortification of Vadu, situated respectively at the western and southern limits of the Razim-Sinoie lagoon. There are still numerous scientific debates on the origin and evolution of the Danube Delta and the Black Sea. The specific studies on the recent evolution of the Danube's mouths (Antiquity and the Middle Ages) can provide essential and significant contributions to the habitat's dynamics in relation to the deltaic geomorphology. The rapid changes in the shoreline caused a massive exodus of the populations from the areas covered by water. The Milesian colonies of Histria and Argamum disappeared because of the rising sea level and because a barrier spit was built in front of the Halmyris Gulf, which caused the formation of the Razim-Sinoie lagoon. © 2012 .

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