University Of Cluj-Napoca Research Articles

Critical evaluation of the specimens of Lithobius validus Meinert - species group (Chilopoda: Lithobiidae) from the "Z. Matic" and "Şt. Negrea" collections (Romania)

Critical evaluation of the specimens of Lithobius validus Meinert - species group (Chilopoda: Lithobiidae) from the "Z. Matic" and "Şt. Negrea" collections (Romania) Z. Matic's collection, preserved at the Zoological Museum of the "Babeş-Bolyai" University of Cluj-Napoca, and Şt. Negrea's collection, preserved at the "Emil Racovitza" Speleological Institute of Bucharest (the only chilopod collections existing in Romania) are containing three species of the Lithobius validus Meinert group: L. (L.) validus Meinert, 1872 (sensu Eason, 1974 a), L. (L.) moldavicus Prunesco, 1966 (sensu Negrea, in the present paper) and L. (L.) matici Prunesco, 1966. New synonymies are proposed: Lithobius punctulatus moldavicus Prunesco, 1966 = Lithobius moldavicus Negrea in this work = Lithobius validus Zapparoli, 1994 nov. syn.; Lithobius matici Prunesco, 1966 = Lithobius matici biharicus Prunesco, 1966 nov. syn. The subspecies Lithobius punctulatus moldavicus Prunesco, 1966 is elevated to the taxonomical rank of species, Lithobius moldavicus Prunesco, establishing its geographical area as it is currently known. The following species are redescribed: Lithobius validus Meinert, 1872, based on the Romanian Carpathians populations; Lithobius moldavicus Prunesco, 1966 based on the specimens of the Eastern Carpathians - including the type series, establishing a lectotypus and an allolectotypus; Lithobius matici Prunesco, 1966 based on populations from the Eastern Carpathians and the Western Carpathians.

Surface roughness of intraocular lenses with different dioptric powers assessed by atomic force microscopy

To analyze the optic surface roughness and morphology of 2 types of hydrophobic acrylic intraocular lenses (IOLs) with various dioptric powers using atomic force microscopy (AFM). Technical University of Cluj-Napoca, Faculty of Mechanics, Cluj-Napoca, Romania. Atomic force microscopy was used to characterize the topography of 2 types of hydrophobic acrylic IOLs from a single manufacturer (SN60AT and SA30AL) with dioptric powers ranging from 10.0 diopters (D) to 30.0 D. The AFM analysis was performed in contact mode using a V-shaped silicon nitride cantilever with a pyramidal tip curvature of 15 nm and a nominal spring constant of 0.2 N/m. Detailed surface characterization of the IOL optic was obtained using 6 quantitative parameters provided by the AFM software. Five of 6 roughness parameters indicated statistically significant differences (P<.05) between IOLs with different dioptric powers, with the 10.0 D IOL in both models providing the smoothest optic surface. Between models with the same dioptric power, the SN60AT model had lower values of each surface roughness parameter than the SA30AL model. Atomic force microscopy was an accurate tool for assessing the surface properties of IOL optics. Manufacturing processes were responsible for introducing detectable differences in the topography of IOL biomaterials with identical copolymer constituents but different dioptric powers. Nanometric analysis may assist IOL manufacturers in developing IOLs with optimal surface characteristics.

Non-invasive archaeological research in the Roman Castrum from Vărădia, „Rovină” (Caraș-Severin County). A topographic and geophysical study

The historic of the archaeological research of Vărădia locality (Caraș-Severin County) is very complex, as the historiographical debates regarding the archaeological objectives here are older than one century. In 1932, Grigore Florescu conducts an excavation campaign in the „ Rovină” (or “Pustă”) point castrum, unveiling the superior part of the path of the fortified wall and a part of the commandment building (Principia). Starting with 1996, Ovidiu Bozu also begins systematic research archaeological campaigns for the „Rovină”/„Pustă” point. Since 1999 Eduard Németh from „Babeș-Bolyai” University of Cluj Napoca, joined the research team. At the end of July 2008 a team from the West University of Timisoara (Dorel Micle, Liviu Măruia and the student Lavinia Bolcu) performs a topographical survey with the total station of the „Rovină” point castrum, and for another week the team performs a geophysical prospection of the same objective. The topographical survey precisely revealed many morphological aspects of the Vărădia „Rovină” castrum as they are visible nowadays on the terrain : oriented on the SSE-NNW direction, exact dimensions (140x160 m), the relevance of the area’s microrelief (the castrum builders speculated a higher terrace located between divagating windings of Caraș River, but which were affected by modern earthworks of territory layout), and the defining of positioning landmarks reporting to present anthropic and natural structures (roads, bridges, canals, etc.). The high precision topographical plans will be used in the future for correct excavation plans layout (sections, cassettes, etc.) for further systematic archaeological research. The results of the magnetometric prospection revealed many aspects and feature with technical and historic nature : a) it allows the correct identification of the archaeological sections excavated in time ; b) it allows the identification of structures affected by older archaeological excavations ; c) proves the existence of a double enclosure wall ; d) it allows the identification of the E tower of the Porta Praetoria ; e) it is spectacular the revelation of the stone foundation traces of the centurion houses, and their orientation and dimensions, the barracks that flanked Via Praetoria ; f) it allows the observation of anomalies caused by metal presence in the barracks area which could indicate a workshop (Fabrica) ; g) some curtain towers are also visible on the S, N and W sides ; h) it allows the identification of intersecting roads in front of Principia, Via Praetoria and Via Principalis ; i) it proves the existence of only one defense ditch, visible on the N side.

The Problems of Higher Education Funding: The Case Study of “Babes-Bolyai” University of Cluj-Napoca, Romania

Our study is intended to analyze: a) the issue of higher education under funding; b) the “disguised subsidizing” of higher education based on tuition fees; c) the supplementary revenues sources for universities; d) the funding mechanisms of higher education. We aim to incite debate on the relation between the educational policy and the funding strategy of higher education at both national and operational levels, instancing the case of the Babes-Bolyai University of Cluj-Napoca. The fundamental guide marks of this analysis are: the average cost per student, the budgetary allowance and the tuition fee. What sources of supplementary revenues for universities are there? What kind of scientific research provides incomes? Which university services generate supplementary resources? How can the university infrastructure be “exploited”? In what measure the cooperation and partnership opportunities with the economic and social environment are being identified? Which are the facilities, the steering directions, the conditions and the benefits of accessing European Structural Funds? With the purpose of answering these questions we have conceived a funding strategy model, entailing: regulations, institutional infrastructure, working instruments, budgetary allowance distribution models, educational costs estimation methods, funding mechanisms, all these operating in a gearing meant to attain, by solving the problems, the objectives of higher education policy.

New technologies and applications of EDM process

Within the Faculty of Machine Building from the Technical University of Cluj-Napoca, Romania unconventional technologies researches were performed for 20 years. The team focused on national research projects referring to micro machining and special applications. EDM process (Electric Discharge Machining) has a great importance to the industry. Even if it never be able to compete with the metal cutting manufacturing process in terms of material removal rate, today it is the main manufacturing process of complex die and mould, due to the major advantages presented in this paper. Today, also the precision of the process competes with the milling process in terms of quality of the surface, which can arrive at values that, in some cases, are better than the values for grinded surfaces. The article presents the importance of the process in the industry of stamps, which can not be processed with other methods, due to special materials and forms that are wished to be obtained. The article presents comparatively the values of the roughness obtained by EDM process on different types of materials and by different process parameters. Concerning the optimisation of the EDM technological parameters, the research has been done on different types of EDM machines. The final scope is to elaborate a technological data base with the purpose of optimising the EDM process on different machines.

EEG processing with TESPAR for depth of anesthesia detection

Address: 1Center for Cognitive and Neural Studies (Coneural), Cluj-Napoca, Cluj, Romania, 2Clinic for Anesthesiology, Johann Wolfgang Goethe University, Frankfurt, Germany, 3Max Planck Institute for Brain Research, Hesse, Frankfurt am Main, Germany, 4Clinic for Anesthesiology, Ludwig Maximilians University, Bavaria, Munich, Germany, 5Frankfurt Institute for Advanced Studies, Johann Wolfgang Goethe University, Frankfurt, Germany, 6Dep. of Anesthesia and Critical Care, Massachusetts General Hospital, MA, USA and 7Department of Electronics, Telecommunications, and Information Technology, Technical University of Cluj-Napoca, Cluj, Romania

Properties of water-atomised prealloyed manganese-carbon steel powders : N. Sechel, R.L. Orban. (Technical University of Cluj-Napoca, Cluj-Napoca, Romania.)

Properties of water-atomised prealloyed manganese-carbon steel powders : N. Sechel, R.L. Orban. (Technical University of Cluj-Napoca, Cluj-Napoca, Romania.)

Production of sintered carbon steel from iron and cast iron powders : I. Chicinas et al. (University of Cluj-Napoca, Cluj-Napoca, Romania.)

Asian lotus (Nelumbo nucifera Gaertn.) is an aquatic plant with ornamental, cultural, economic, and ecological values. China has abundant germplasm resources of Asian lotus. However, in many areas, the wild Asian lotuses have been destroyed and the germplasms is now facing extinction. In addition, the knowledge of the genetic diversity of the wild Asian lotus in China is poor. To identify and protect the germplasms of Chinese wild Asian lotus, eleven genomic-SSR primers, three EST-SSR primers, and three chloroplast DNA primers were used to investigate the genetic diversity among 69 samples of wild Asian lotus from 25 locations in northern China. The genetic diversity of 27 samples of wild Asian lotus from southern China and other countries, the ancient Asian lotus, Asian lotus cultivars from China, and Asian-American hybrids was also compared. The genetic diversity of the wild Asian lotus from northern China was characterized as medium, and the mean values of observed heterozygosity (Ho) and expected heterozygosity (He) were 0.087 and 0.552, respectively. Based on a UPGMA dendrogram and STRUCTURE analysis, the wild Asian lotus samples in northern China were divided into three groups. The wild Asian lotus samples from northern China contained 16 haplotypes. The Nei's genetic distance between the wild Asian lotus samples from the Songhua River basin and the Liao River basin in northeastern China was relatively small, and these germplasms might be relatively primitive compared to those from other regions. This study provides essential information regarding the genetic diversity of the wild Asian lotus resources in northern China, and provides a basis for further analysis of population-level genetic evolution through high-throughput sequencing.

The Multicultural Babe y -Bolyai University of Cluj-Napoca

Both the ethnic history of Transylvania and the history of higher education in the region are traced, particularly the history of Babe y -Bolyai University of Cluj-Napoca, which dates back to 1541. Today, this institution is a trilingual university offering lines of studies in Romanian, Hungarian, and German, as enshrined in the university charter of 8 July 2000. The trilingual instructional system, which is described in some detail, works well even if Romanians constitute the dominant ethno-linguistic group in Transylvania. The author proposes the model of Babe y Bolyai University as a very suitable way to accommodate ethno-linguistic diversity in a united Europe.

Astronomy in Romanian Universities

In this work we present characteristics of the Romanian higher education related to the study of Astronomy. In spite of Romanian economic problems, opportunities for Bachelor’s degree, Master’s degree (at “Babes-Bolyai” University of Cluj-Napoca) and Ph.D. degree are provided for students enrolled in the Faculties of Mathematics or Physics. General regulations, description of courses, research resources and job opportunities are also described and discussed in this paper.

Effect of ammonium molybdate particle size and structure on processing of molybdenum: R.Orban et al. (Technical University of Cluj-Napoca, Romania.)

Effect of ammonium molybdate particle size and structure on processing of molybdenum: R.Orban et al. (Technical University of Cluj-Napoca, Romania.)

Compaction of stainless steel by rotary forging : T.Canta et al. (Technical University of Cluj-Napoca, Cluj-Napoca, Romania.)

The control of the corrosion phenomenon occurring at the metal interface requires the development of new non-toxic anticorrosion additives. For this purpose, zirconium orthophosphate compounds (Zr(HPO4)2,H2O noted α-ZrP) were synthesized by both hydrothermal and refluxing methods The Ca2+-cationic exchange in the layered structure is kinetically favoured by low crystallinity of α-ZrP synthesized by refluxing process, and leads to the formation of CaZr(PO4)2,4H2O, noted Ca2+-ZrP. The H+/Ca2+ exchange mechanism is mainly triggered by acid-base considerations, and especially the pKa of α-ZrP/Ca2+-ZrP acid-base couple (evaluated to 2.5). Both compounds are acidic compounds by internal exchangeable H+ for α-ZrP and surface protons for Ca2+-ZrP, and can be used as potential inhibitors of zinc corrosion. Electrochemical measurements show that Ca2+-ZrP compounds dispersed in the NaCl electrolyte buffer the pH value over a long time and therefore allow controlling the corrosion rate of zinc.

Crystal structure of rapidly cooled aluminium powders: G.Arghir, E.Abrudan. (University of Cluj-Napoca, Cluj-Napoca, Romania.)

Crystal structure of rapidly cooled aluminium powders: G.Arghir, E.Abrudan. (University of Cluj-Napoca, Cluj-Napoca, Romania.)

Thermo-chemical treatment of PM materials with carbon and nitrogen: V.Iancau et al. (Technical University of Cluj-Napoca, Cluj-Napoca, Romania.)

Coarse grained WC–9Co cemented carbides with 0–1.0% TaC (mass fraction) were fabricated by HIP-sintering and gas quenching. The effects of TaC on the microstructures and mechanical properties were investigated using scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDS), X-ray diffractometry (XRD) and mechanical properties tests. The results show that the maximum values of hardness and strength are HV 1124 and 2466 MPa respectively when 0.4% TaC is added. When the content of TaC is more than 0.6%, the grain size of WC is no longer affected by the amount of TaC, and (W,Ta)C occurs as well. Moreover, the strength and fracture toughness increase and the (Ta+W) content decreases with the increase of TaC content. The dependence of (Ta+W) content on the mechanical properties indicates that (Ta+W) content in Co should be decreased as low as possible to improve the mechanical properties of coarse grained WC–TaC–9Co cemented carbides with the microstructure of WC+γ two phase regions.

Influence of aluminium on sintered titanium base compacts : V.Candea et al. (Technical University of Cluj-Napoca, Cluj-Napoca, Romania.)

Influence of aluminium on sintered titanium base compacts : V.Candea et al. (Technical University of Cluj-Napoca, Cluj-Napoca, Romania.)

Application of longitudinal vibrations to sintered parts : G.Arghir et al. (Technical University of Cluj-Napoca, Cluj-Napoca, Romania.)

Application of longitudinal vibrations to sintered parts : G.Arghir et al. (Technical University of Cluj-Napoca, Cluj-Napoca, Romania.)

Alloying of silver-tin powders by ball milling: R.Orban et al. (University of Cluj-Napoca, Romania.)

Alloying of silver-tin powders by ball milling: R.Orban et al. (University of Cluj-Napoca, Romania.)

Production of metal powders by atomization under water: G.Matei et al. (University of Cluj-Napoca, Cluj-Napoca, Romania.)

Production of metal powders by atomization under water: G.Matei et al. (University of Cluj-Napoca, Cluj-Napoca, Romania.)

Sintering by infiltration of loose powders: R.Orban et al. (Technical University of Cluj-Napoca, Romania.)

Sintering by infiltration of loose powders: R.Orban et al. (Technical University of Cluj-Napoca, Romania.)

Prediction of wear resistance of hardmetals from hardness : S.Domsa, R.Orban. (Technical University of Cluj-Napoca, Cluj-Napoca, Romania.)

Prediction of wear resistance of hardmetals from hardness : S.Domsa, R.Orban. (Technical University of Cluj-Napoca, Cluj-Napoca, Romania.)