Two independent ovarian cancer cell lines and fibroblast controls were treated with nonequilibrium atmospheric pressure plasma (NEAPP). Most ovarian cancer cells were detached from the culture dish by continuous plasma treatment to a single spot on the dish. Next, the plasma source was applied over the whole dish using a robot arm. In vitro cell proliferation assays showed that plasma treatments significantly decreased proliferation rates of ovarian cancer cells compared to fibroblast cells. FACS and Western blot analysis showed that plasma treatment of ovarian cancer cells induced apoptosis. NEAPP could be a promising tool for therapy for ovarian cancers.

A fluid lubrication model for articular cartilage was put forward by McCutchen, in which a high percentage of the load is supported by fluidpressurization in the interface region separating the two cartilage coatedsurfaces as the cartilage is compressed under load. This reduces thefriction by reducing the percentage of the load which is carried by solidmaterial in the cartilage. For two bones which are in contact in a healthyjoint, which are each coated by a layer of cartilage whose thickness is muchsmaller than its lateral dimensions, it will be argued that since the boneis impervious to fluid flow in healthy joints, almost all of the fluid thatis expressed from the cartilage under load flows through the interfaceregion, where it supports part of the load. This is in contrast to previoustheoretical and in vitro experimental studies of this problem, in which mostof the fluid does not flow into the interface. It is shown that for meanasperity height small compared to a length scale (which depends on thecartilage or hydrogel permeability, the fluid viscosity and the dimensionsof the cartilage or hydrogel) a large percentage of the load is supported byfluid pressurization.

Above 750-800°C oxidation becomes a serious life time issue for the new group of intermetallic light-weight high temperature alloys based on titanium aluminides (TiAl). Fast growing titanium oxide competes with protective alumina as a surface scale in the oxidation reaction by which the formation of a slow-growing protective oxide scale is prevented. The key to the development of alloys with sufficient oxidation resistance is the understanding of the thermodynamic and kinetic situation during the oxidation process. The latter is influenced by the type of alloying elements, the Al- and Ti-activities in the alloy, the oxidation temperature and the environment (e.g. dry or humid air, etc.). This paper provides a comprehensive summary of the oxidation mechanisms and the parameters influencing oxide scale formation. Besides the role of metallic alloying elements, the halogen effect will also be discussed. The paper finishes with recent results concerning the prevention of oxidation-induced room temperature embrittlement of TiAl alloys.

The geological disposal of radioactive waste, based on a multi-barrier concept wherein the first barrier consists of the metal waste container and the final barrier the host rock, is widely considered the only viable solution.

Following disposal the risk will remain of the formation of gases due to corrosion and other processes. Research being carried out at the Czech Technical University in Prague (CTU), Centre of Experimental Geotechnics (CEG), the Josef underground laboratory as part of FORGE and other projects focuses on gas migration in underground areas and especially within the EDZ.

The research consists of several stages including the design of gas conductivity equipment destined for in-situ testing and the gas conductivity tests proper. An important part of the research involves the evaluation of a potential correlation between rock mass classification parameters and gas conductivity; a certain degree of correlation was identified in earlier research projects. The discovery of such a correlation would greatly assist in the future design of underground gas storage and deep radioactive waste facilities.

Recently there have been a number of reports indicating concern relating to the effect of porosity, pore size distribution, and pore interconnectivity on the integration of highly porous ultra low-k organosilicate glasses (OSGs) as back-end-of-line (BEOL) interconnect dielectrics. In an effort to address these concerns a number of options to control the skeleton and pore structure of OSGs have been proposed, from adding alternative OSG precursors to alternative porogen precursors. In all these options there is a need to balance pore structure modification with critical film properties such as dielectric constant and mechanical strength. In this context, this paper examines porosity and its impact on film properties for highly porous ultra low dielectric constant films. A series of PDEMS® porous OSG films were deposited by plasma enchanced chemical vapor deposition (PECVD) from DEMS® precursor (diethoxymethylsilane) and porogen ATRP (alpha-terpenine). The percent porosity and pore interconnectivity of these films relative to the dielectric constant were measured by ellipsometric porosimetry (EP) and positron annihilation spectroscopy (PALS) respectively. Porosity and pore-size distribution for films deposited using several different species (structure former or porogen precursors) were examined using EP in an effort to understand the impact of the chemical nature of the precursor on pore morphology. Results from these depositions show that it is possible to deposit films with smaller pores using alternative structure formers (ASFs) with bulky organic groups, although there are tradeoffs with respect to other film characteristics. The addition of a separate porogen (ATRP) to the ASF lowered the dielectric constant and the addition of DEMS® precursor to the ASF/ATRP mix gave the films added structural integrity and mechanical strength. Such a fundamental understanding of structure-property relationships will help support successful integration of these porous OSG films.

We investigated continuous fabrication of a large area 2-D metamaterial comprising a metal dot array on a dielectric coated substrate. We demonstrated patterning of metal dots arrays of varying patterns and shapes with diameter of about 2.5 μm and metal-to-metal spacing from 0.3 to 2.5 μm using a nano-imprinting stamp on a roller. The pattern was first fabricated on a standard photolithography mask, reproduced onto a silicon wafer master mold, and then transferred to a flexible polymer mold that was wrapped around a metal roller. The method was used to pattern a thin Al layer on top of SiO2 on a flexible polymer substrate. The aluminum was coated with a resist and the roller moved over the substrate with adjustable speed and pressure to imprint the fine pattern into the resist. The resist was cured, and a very thin layer of residual resist was removed by RIE, followed by a standard etching treatment for patterning the aluminum layer.

The as-etched pattern had very few defects and the optical properties of the metamaterial were excellent and correlated well with simulations. This work has shown that low cost, rapid roll-to-roll processing of 2-D metamaterial structures is possible.

The reversible switching between the amorphous and crystalline phases of Ge2Sb2Te5 (GST) is investigated with ab initio molecular dynamics. We apply different quench rates (-16 K/ps, -5 K/ps, -2 K/ps, and -0.45 K/ps) and different annealing temperatures (500 K, 600 K, 700 K, and 800 K) to amorphize and crystallize GST respectively. Results show that the generated amorphous is strongly dependent on the quench rate. For -16 K/ps and -5 K/ps, generated amorphous samples have different density of crystal seeds, higher in the later. The amorphous structure formed at -2 K/ps contains a single crystalline cluster, while that formed at the quench rate of -0.45 K/ps had sufficient time to completely crystallize the amorphous phase. Annealing the amorphous systems formed at different rates shows that crystallization depends both on the annealing temperature and on the structure of the initial system (i.e., whether or not it contains crystalline clusters or crystal seeds). At 500 K, formation of crystalline clusters occurs readily within a few ps while the rate at which they grow is slow, taking 0.9 ns to complete the crystallization. In contrast, crystalline cluster formation is inhibited at 800 K. In the intermediate temperature range, both crystalline cluster formation and growth occur within a few hundred ps indicating that these temperatures leads to the fastest crystallization. The crystallization of a 63-atom at ∼900 K resulted in a highly relaxed crystal structure showing a clear tendency for separation of Ge and Sb species in layers. This model also indicates a tendency of segregation of vacancies, suggesting that vacancy layering may play a key role in the crystallization process.

Patterned micro-and nanowires composed of Iron Oxide (FexOy) were electrochemically deposited from an ionic liquid solution of choline chloride (ChCl) and urea, using ultrananocrystalline diamond (UNCD) ™ templates originally developed for Electroplate and Lift (E&L) Lithography. The wires were electroplated under varying rigor of anhydrous and inert atmosphere techniques, at voltages of either -2V or -5V vs. an Al/Al(III) reference electrode. The morphology of the deposited FexOy wires was studied by scanning electron microscopy (SEM), while their oxygen content was evaluated using energy dispersive spectroscopy (EDS). By using sublimed grade reagents and minimizing exposure to atmospheric water vapor and oxygen, the oxygen content of the electroplated wires decreased from 15 at% to 5 at%.

Thin films of antimony sulfide (Sb2S3) were prepared with different silver-ion content in a chemical deposition bath, and silver antimony sulfide (AgSbS2) was produced through the addition of higher concentrations of silver-ions in the bath. The chemical deposition solution mixture contained antimony trichloride (SbCl3) and sodium thiosulfate (Na2S2O3). For molar ratio, AgNO3:SbCl3, 0.002 – 0.02, XRD patterns of the Sb2S3-Ag films heated at 280 ºC match that of the mineral stibnite (Sb2S3). The optical band gap (Eg) of these films is in the 1.93-1.80 eV range. At higher molar concentrations of Ag, lower is the Eg of the films. Electrical conductivity under illumination (σph) is 7.4x10-5 Ω-1cm-1 for a film with Ag:Sb 0.002 in the bath, which is about three orders of magnitude higher than that of a film prepared without Ag. At Ag:Sb 0.2, the XRD pattern of the heated film shows the presence of Ag3SbS3 and AgSbS2. Single-phase AgSbS2 (cubic miargyrite, a = 0.5652 nm) film is formed for Ag:Sb 0.4 and the film heated at 260 o C. The Eg of the film is 1.75 eV for the Sb2S3/Ag-Sb-S film and 1.68 eV for AgSbS2. Solar cell structures of TCO(SnO2:F)/CdS(200 nm)/Sb2S3(150 nm)/graphite, as well as with Sb2S3-Ag absorbers were developed through sequential chemical deposition. The cells with the colloidal graphite paint on the absorber were heated at 260 ºC for 15 min each. The Voc of the cells are 620-635 mV, with the cell using Sb2S3-Ag (0.004) film showing a Jsc of 2.00 mA/cm2, which is higher than the 1.69 mA/cm2 observed in cells with Sb2S3 absorber. In cells using AgSbS2 absorber, Voc is 490 mV, and Jsc is very low, 0.12 mA/cm2. The present work offers a wider range of absorber materials for thin film and hybrid solar cells.

We present extensive pseudopotential density functional theory calculations dedicated to analyze the stability, electronic properties, and structural isomerism in Cu6 clusters. We consider structures of different symmetries and charge states. Our total energy calculations reveal a strong competition between two- and three-dimensional atomic arrays, the later being mostly energetically preferred for the anionic structures. The bond lengths and electronic spectra strongly depend on the local atomic environment, a result that is expected to strongly influence the catalytic activity of our clusters. Using the nudged elastic band method we analyze the interconversion processes between different Cu6 isomers. Complex atomic relaxations are obtained when we study the transition between different cluster structures; however relatively small energy barriers of approximately 0.3 eV accompany the atomic displacements. Interestingly, we obtain that by considering positively charged Cu6 + systems we reduce further the energy barriers opposing the interconversion process. The previous results could imply that, under a range of experimental conditions, it should be possible to observe different Cu6cluster structures in varying proportions.

For the gate last approach of a high K metal gate scheme used in advanced CMOS technology, various materials were tested as wetting layers to allow Aluminum (Al) gap fill at gate widths of10 to 45 nanometers. In this study, Titanium (Ti) and Cobalt (Co) were investigated as a wetting layer for Al gap fill. It was discovered that Al-Ti and Al-Co alloys were formed during high temperature Al deposition. Alloys were characterized using XRD. Alloy’s impacts on line resistivity and subsequent Al Chemical Mechanical Polish (Al CMP) were also investigated. In addition, a model was established to predict the alloy type and alloy mole% with respect to feature size. The predicted Al mole% by this model correlated very well with 1) line resistivity trend and 2) morphologies. The model also predicted that due to Al lower electro-chemical potential than Ti, Co or its alloys, galvanic corrosion could take place depending on the chemical environment in the Al CMP slurry. Different slurry or cleaning chemical may reduce or increase the risk of galvanic corrosion. The knowledge gained with the help of the model provides clear directions on selection criteria for wetting layers, optimization for deposition processes and Al CMP consumable design to meet the challenges.

In an effort to realize high-speed organic logic components, p- and n-type single-crystal organic field-effect transistors (SC-OFETs) were fabricated using air-gap structures with channel lengths as short as several μm. High carrier mobility of about 10 cm2/Vs is demonstrated in rubrene SC-OFETs even with the short channel length of 6 μm, using Si-based microstructures. The contact resistance is estimated to be 450 Ohm cm, which is only 5% of the total channel resistance between source and drain electrodes. Performances of n-type air-gap devices based on PDIF-CN2 are also demonstrated exhibiting electron transport with the carrier mobility of about 2 cm2/Vs. Furthermore, micron-scale air-gap structures are fabricated using insulating materials on glass substrates to reduce parasitic gate capacitance. The cut-off frequency of this rubrene air-gap device is measured to be as high as 8 MHz with applied drain voltage VD of 15 V. These techniques are promising to be applicable to next-generation organic high-speed logic circuits.

In this study we compare light trapping in hydrogenated amorphous silicon (a-Si:H) solar cells deposited directly onto polycarbonate (PC) at low temperature (< 130°C). To that end, we embossed PC substrates with 400 nm and 10 μm square based pyramids to induce light trapping based on diffraction and on geometric effects. As a comparison, we deposited a-Si:H cells on flat glass substrates and on Asahi U-type TCO glass. The cells on PC generate current densities comparable (slightly higher) than cells on Asahi TCO glass, but suffer from a slightly lower Voc, resulting in cells with an initial efficiency of 6.8% and 7.4% on sub-micron pyramid and micro-pyramid structured PC substrates respectively, compared to 7.6% for cells on Asahi. This shows great potential for a-Si:H cells deposited directly onto cheap plastics.

Electronic structure calculations using the Heyd-Scuseria-Ernzerhof (HSE) hybrid functional are presented for NO-pair complexes with and without hydrogen to test the hypothesis that such defect complexes could lead to shallower levels than for isolated NO and hence p-type doping. The H is found to bind strongly to one of the N in the pair and removes thecorresponding defect level from the gap but the second N’s polaronic defect level in the gap remains deep.

Coal deposits in Mexico were firstly recognized back in 1850, the main coal deposits in Mexico are located north of the Coahuila State. Coal samples from coal mines of Sabinas Basin were collected and analyzed for chemical composition, separation characteristic and calorific value (CV). The analytical data indicate that the coals usually have low or high ash content (Ash), 17 – 50 wt %, depending on the sample source. Comparison of the calorific value with both ahs content and fixed carbon, indicate that these two parameters are directly connected together: the higher the calorific value of coal, the lower the ash content and high fixed carbon content. Rejection of the ash using sink-flotation technique and their ratio whit the calorific value (CV/Ash) was evaluated in this study. Also, the ratio of Calorific value to fixed carbon (FC) was analyzed. Washability analyses for selected coal sample (+1 ½”, -1 ½” + ½”, -½” +¼“, - ¼“ + 1/16”, -1/16” +#100, size group) using heavy organic liquids with a density from 1.3 to 1.6 gr/cm3, were carried out. Calorific value-ash (%)-Fixed Carbon relationship was presented. The results indicate that the ratio CV/Ash vs. specific gravity has an exponential behavior, whereas the value of the ratio CV/FC was found to be 117.3.

The interactions of fully stripped Argon-40 heavy ion beams with 140 MeV/nucleon with a series of increasingly polygonal carbon onions are investigated by high-resolution transmission electron microscopy and thermogravimetric analysis. The experimentally observed graphene layer linking is compared with expected results from the displacement and dislocation migration models. The results suggest that dislocation-driven mechanisms may play a significant role in graphene layer linking induced by heavy ion interactions with carbon onions.

Er doped ZnO (Er:ZnO) thin films with Er concentration from 0.1 to 3.6 at. % were prepared by dual beam ion beam sputter deposition at room temperature. Experimental results show that as Er concentration increases from 0.1 to 1.1 at. %, the resistivity of the as-deposited Er:ZnO film decreases from 560 Ω·cm to a minimum of 0.23 Ω·cm, while further increasing Er concentration to 3.6 at. % results in increase of the resistivity to 4.2 kΩ·cm. The as-deposited Er:ZnO with Er concentration of 1.1 at.% also exhibits the highest carrier concentration of 2.3×1019 cm-3. None of the as-deposited Er:ZnO films show 1.5 μm emission without post-growth annealing. Er:ZnO film with Er concentration at 0.5~1.1 at.% shows the strongest 1.5 μm emission after annealing at 700 ~ 900°C, while all the Er:ZnO film becomes semi-insulating after annealing. The discrepancy between the processing conditions for optimized carrier concentration and optimized optically activated Er ions may due to the formation of the pseudo-octahedral structure after annealing that favors the 1.5 μm emission.

As scientists are able to understand and manipulate ever smaller scales of matter, research in the fields of biotechnology and nanotechnology has converged to enable such radical innovations as lab-on-a-chip devices, targeted drug delivery, and other forms of minimally invasive therapy and diagnostics. This paper provides a descriptive overview of the emerging bio-nano sector, identifying what types of firms are entering, from what knowledge base, where they are located, and their strategic choices in terms of technological diversity and R&D strategy. The firms engaged in bio-nano research and development span the range from start-up firm to multinational pharmaceutical, biotech, chemical, and electronics firms: two thirds of bio-nano firms are relatively young and relatively small. The United States dominates this sector, with more than half of all bio-nano firms located in the USA. Even within this sector which epitomizes the convergence of technology, there is a broad range of technological diversity, with the most diverse firms overall coming from a base in electronics, the most diverse start-up firms coming from a base in nanomaterials, and the most narrowly focused firms coming from a biotechnology/pharmaceutical base. We find that hybridization has been the dominant knowledge diversity strategy, with 93% of the bio-nano firms with nano-patents holding multiclass patents.