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Niobium nitride is used in a wide range of application due to its mechanical, physical, chemical, electrical and optical properties. The main aim of this paper is to deposit niobium nitride thin films by direct current magnetron sputtering and to characterize them at nanoscale. The films were deposited on silicon Si (100) substrates. Three types of films were deposited by modifying the deposition temperature. In this regard, some of the samples were deposited at room temperature (25 °C), some were deposited when the substrate was preheated at 200 °C, and the rest at substrate temperature of 400 °C. Regarding the topography of the samples, an increase in the average roughness was determined with the increase in deposition temperature. The nanoindentation tests were carried out at temperatures between 20 and 100 °C so that to emphasize the change in hardness and modulus of elasticity in terms of testing temperature. The results pointed out an important influence of both the deposition temperature and testing temperature on the topography, adhesion and mechanical properties of the niobium nitride thin films.

Thin films present interest for researchers due to their applicability in areas such as developing microelecromechanical devices, hard coatings, cutting tools and diffusion barriers. This paper is focused on studying the influence of the testing temperature on the mechanical properties of chromium nitride (CrN) thin films. For this purpose, CrN thin films were deposited by direct current magnetron sputtering on silicon substrate using a chromium target of high purity. All the films were obtained by keeping almost all deposition parameters constant, while the nitrogen flow rate was varied. Hence, three types of samples of CrN thin films were obtained using different nitrogen flow rates namely 2 cm3/min, 4 cm3/min and 6 cm3/min. The mechanical properties of these thin films such as the hardness and Young’s modulus were investigated by performing nanoindentation using an atomic force microscope. All experimental investigations were conducted by varying the testing temperature between 20 oC and 100 oC. The purpose was to find the dependency between the testing temperature and the mechanical properties of CrN films deposited at different nitrogen flow rates. The obtained experimental results indicate a significant influence of the testing temperature on the properties of the studied CrN thin films.

Titanium nitride can be used among other materials as diffusion barrier for MEMS (microelectromechanical systems) applications. The aim of this study is to elaborate and to characterize at nanoscale titanium nitride thin films. The thin films were deposited by reactive magnetron sputtering on silicon substrates using a 99.99% purity titanium target. Different deposition parameters were employed. The deposition temperature, deposition time, substrate bias voltage and the presence/absence of a titanium buffer layer are the parameters that were modified. The so-obtained films were then investigated by atomic force microscopy. A significant impact of the deposition parameters on the determined mechanical and tribological characteristics was highlighted. The results showed that the titanium nitride thin films deposited for 20 min at room temperature without the presence of a titanium buffer layer when a negative bias of −90 V was applied to the substrate is characterized by the best tribological and mechanical behavior.

The development of micro-and nanoelectromechanical systems (MEMS/NEMS) makes use of different thin films such as aluminum, gold, silicon, silver, titanium nitride, silicon carbide etc. This study is a research concerning the influence of substrate nature on the tribological and mechanical characteristics of gold thin films elaborated by thermal evaporation method, for space applications. Three different substrates were employed, namely: C45 steel, plastic (polycarbonate) and glass. Atomic force microscopy investigations were performed in order to characterize the obtained thin films at nanoscale. The nanohardness, Young’s modulus, roughness and the friction force are some characteristics that were determined. A significant influence of substrate nature on both mechanical and tribological properties of researched gold thin films was marked out. Regarding the topography, the smallest roughness was determined on the gold thin films deposited on glass substrate.

Aluminum, gold, silver, nickel, silicon, glass, silicon dioxide, silicon nitride and so on, employed as bulk materials or thin films, represent the most commonly used materials for MEMS applications within the automotive, biomedicine, spatial industries and so forth. This work is a study regarding the influence of substrate nature on the mechanical properties of silver thin films elaborated for MEMS devices. The silver thin films were obtained by thermal evaporation method under vacuum protection on three different substrates. Glass, plastic (polycarbonate) and steel (C45) respectively are the materials used for the substrates. Further, atomic force microscopy investigations were performed on the elaborated samples in order to characterize them at a nanoscale and establish substrates influence. The Young’s modulus, nanohardness and roughness of the researched samples are the characteristics that were determined. A significant influence of substrate nature on the properties mentioned above for the studied silver thin films was marked out.

We compared two dosing schedules for subcutaneous injections of a low-dose humanized anti-CD20 antibody, veltuzumab, in immune thrombocytopenia. Fifty adults with primary immune thrombocytopenia, in whom one or more lines of standard therapy had failed and who had a platelet count

Nitriding is usually applied to alloyed steels with the scope of increasing their surface hardness and wear resistance. Warm working has been found to produce a fine-grained microstructure, which makes possible further treatment of low carbon steels. In combination with a low temperature thermochemical treatment, such as nitriding, warm working can be used to produce machine parts with a though core and with a hard, wear resistant surface layer. This paper presents a study of mechanical and structural properties of AISI 1015 carbon steel nitrided after warm rolling. The rolling was performed in the following conditions: temperature 670–550°C, rolling speed 1.39 s-1 and deformation ratio 36.4%. After rolling, the samples were reheated to 550°C for a duration varying from a few minutes to 10 hours. The microstructural changes were assessed by light microscopy and quantitative microscopy analysis. Warm rolled samples were ion nitrided at 510–520°C in dissociated ammonia. The microstructure was analyzed by scanning electron microscopy and the mechanical properties were evaluated by tensile testing, surface hardness and friction coefficient measurements. Prior application of warm rolling makes possible (in the sense that is a viable solution) the ion nitriding of low carbon steels in order to produce machine parts with improved mechanical properties in the core (due to warm rolling) and longer service life (due to ion nitriding).

The experimental researches was made on X3CrNiMo17-13-3 stainless steel samples ion nitrided at different temperatures, duration and work atmospheres. The analysis of superficial layers was made in order to identify the microstructure of the ion nitrided layer using X-ray diffraction, and also the determination of the superficial hardness and hardness gradient. The nitrided samples were subjected to two thermal shock regimes, one in the range of 500-20°C and the other in the range 600-20°C. The crack and crack networks initiation process as a result of thermal fatigue was analyzed quantitatively and qualitatively using optical microscopy. The study of the cracking process highlighted the fact that thermal shock resistance is influenced by the characteristics of the superficial layer and also by the maximum temperature of the thermal stress cycle.

Using controlled low-energy ion bombardment, CrN and Cr2N films were reactively sputtered from a Cr target in a mixed Ar-N2 discharge. Various Cr-N based coating architectures were developed in this work to provide better substrate accommodation than is currently available using monolithic CrN or Cr2N, as well as to build in “load support” for the hard surface layers on more compliant substrates. A series of monolithic and multilayer structures were deposited at low temperatures (

Different nitrides such as titanium nitride, chromium nitride and so on are used in a widespread range of applications such as cutting tools, medical implants, and microelectromechanical devices and all that due to their mechanical, physical and chemical properties. The aim of this study is to obtain chromium nitride thin films and to characterize them by atomic force microscopy investigations. The chromium nitride thin films were deposited by reactive magnetron sputtering on silicon substrates. During the deposition process, the discharge current, the argon and nitrogen flows, the pressure inside the chamber and the deposition time were kept constant. A chromium target with a purity of 99.95 % was used. Some of the films were deposited after a chromium buffer layer was previously deposited on the silicon substrate. The deposition was carried out when substrate temperature was at room temperature, at 300 and 500°C respectively. Once the films were deposited, atomic force microscopy investigations were performed in order to emphasize the influence of the substrate temperature on the topographical, mechanical and tribological characteristics. The results pointed out an important influence of the substrate temperature on topographical, mechanical and tribological properties of the investigated chromium nitride thin films.

The main goal of this paper is to study the influence of the temperature on the mechanical and tribological characteristics of titanium nitride thin films. The titanium nitride thin films were deposited by reactive magnetron sputtering on silicon substrates using a titanium high purity target. The films were deposited in different conditions. Several films were deposited on silicon substrate at room temperature while the others were obtained after the substrate was preheated. The majority of the films were deposited on non-biased substrates while the rest were deposited on substrates to which a negative bias was applied. Once the films were deposited, the characterization was realized by atomic force microscopy investigations determining the topographical parameters as well as the mechanical properties such as the modulus of elasticity and the hardness. The mechanical properties mentioned before were determined at 20 °C, 40 °C, 60 °C, 80 °C and 100 °C in order to establish the effect of testing temperature on the mechanical characteristics. The results highlighted a significant influence of temperature on the mechanical and tribological properties of the investigated titanium nitride thin films.

Construction carbon steels represent an important steel class due to the large quantity in which it is produced. Generally, these steels are delivered in as‐rolled or normalized condition heaving a ferrite‐pearlite microstructure. For a given chemical composition, the mechanical characteristics of this microstructure are largely influenced by the grain size. Rolling is the deformation process which is most widely used for grain size refinement. Situated in the intermediate temperature range, warm‐rolling presents certain advantages as compared to classical hot‐ or cold‐working processes.The paper presents a study on the microstructure and mechanical properties of Ck15 carbon steel samples warm‐rolled. After deformation, the microstructure was investigated by light microscopy. Hardness measurements were made on the section parallel to the rolling direction. The mechanical properties of the steel after warm‐rolling were assessed by tensile and impact tests. Additional information concerning the fracture beh...

1.—Department of Mechanical Systems Engineering, Faculty of Machine Building, Technical University of Cluj-Napoca, 103-105 Muncii Avenue, Cluj-Napoca, Romania. 2.—Department of Materials Science and Engineering, Faculty of Materials and Environmental Engineering, Technical University of Cluj-Napoca, 103-105 Muncii Avenue, Cluj-Napoca, Romania. 3.—e-mail: vio1919@ yahoo.com. 4.—e-mail: violeta.merie@stm.utcluj.ro

Titanium nitride thin films are used in applications such as tribological layers for cutting tools, coating of some medical devices (scalpel blades, prosthesis, implants etc.), sensors, electrodes for bioelectronics, microelectronics, diffusion barrier, bio-microelectromechanical systems (Bio-MEMS) and so on. This work is a comparative study concerning the influence of substrate temperature on some mechanical and tribological characteristics of titanium nitride thin films. The researched thin films were obtained by reactive magnetron sputtering method. The experiments employed two kinds of substrates: a steel substrate and a silicon one. The elaboration of titanium nitride thin films was done at two temperatures. First, the obtaining was realized when the substrates were at room temperature, and second, the obtaining was realized when the substrates were previously heated at 250 °C. The elaborated samples were then investigated by atomic force microscopy in order to establish their mechanical and tribological properties. The nanohardness, roughness, friction force are some of the determined characteristics. The results marked out that the substrate which was previously heated at 250 °C led to the obtaining of more adherent titanium nitride thin films than the substrate used at room temperature.

8530 Background: Low IV doses of veltuzumab, a second-generation anti-CD20 monoclonal antibody with structure-function differences from chimeric rituximab, have shown clinical activity, thus justifying subcutaneous (SC) injections. Methods: A phase I/II study was initiated in patients (pts) with previously untreated or relapsed CD20+ indolent NHL or CLL who received 4 SC injections of veltuzumab 2 weeks apart at dose levels of 80, 160, or 320 mg. Efficacy was assessed by CT-based IWG (NHL) or hematology-based NCI/IWCLL (CLL) criteria 4 and 12 weeks later, with responding pts continuing follow-up. Other evaluations included AEs, safety laboratories, B-cell blood levels (CD19), serum veltuzumab levels, and human anti-veltuzumab antibody (HAHA) titers. Results: Nineteen pts (8M/11F, median age 63), including 14 NHL pts (11 follicular, 3 other indolent NHL; 5 treatment naive) most with stage III or IV disease (11/14) and 5 CLL pts (4 treatment naïve) all with Rai stage II or III disease, have now received SC veltuzumab at 80 mg (3 NHL, 3 CLL), 160 mg (9 NHL, 2 CLL) or 320 mg (2 NHL) dose levels. Pre-treatment with antihistamines or steroids has not been required, and SC veltuzumab was well tolerated with only mild, transient injection site reactions and tenderness. To date, all HAHA results have been negative. In NHL pts, SC veltuzumab demonstrates good bio-availability, with a slow release pattern over several days and depletion of circulating B cells starting after 1st injection. Initial response information is currently available for 10 pts. For 7 NHL pts, 4 weeks after treatment with 80 or 160 mg doses, 2 pts had partial responses, 3 pts showed stable disease, and 2 pts had disease progression. For 3 CLL pts who received 80 mg doses, serum veltuzumab levels were lower, but all pts still achieved 65–75% decreases in circulating leukemic cells over the course of treatment. Conclusions: SC administration of veltuzumab is well tolerated, achieves slow but efficient delivery into the blood, and is pharmacologically active. The low doses currently evaluated in B-cell malignancies show evidence of therapeutic activity, achieving objective responses in NHL and notable reductions in circulating leukemic cells in CLL. [Table: see text]

The main purpose of this work is to investigate the influence of ion nitriding on thermal shock behaviour of two stainless steel grades (austenitic and martensitic). Samples made from the two steel grades were first ion nitrided in dissociated ammonia and H-N-CH mixture and then subjected to thermal shock from 600°C and 500°C by using a home made apparatus. The study put into evidence two different types of crack initiation and crack growth on the two steel grades. Possible mechanisms responsible for such cracking behaviour are also proposed.