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The effect of bias voltages (40 V, 80 V, and 40/60/80 V) on microstructure and electrochemical properties of arc-PVD CrN coatings were evaluated. Increasing the bias voltage produced microstructural changes, from well-defined columns to columnar grains, and increased defect size. The electrochemical response proved susceptible to the defect type. Nano-droplets promoted the formation of oxides, while large pores allowed the migration of the electrolyte to the substrate/CrN interface. An impedance equivalent circuit based on the Bisquert transmission line was proposed to fit the experimentally obtained impedance spectra. The equivalent circuit allowed correlating the coating electrochemical response to the defect densities and sizes. Samples deposited with 40 V showed the lowest corrosion current (0.05 μA/cm2 ± 0.01), which was supported by the highest resistances to the transport of ions through the pores (Rp = 1047 ± 88 kΩꞏcm2). Films obtained with 80 V reduced Rp values by two magnitude orders compared to CrN 40 V. The increase of pore resistance in CrN 40 V was associated with the oxidation of nano-droplets (proposed auto-protection phenomenon), which blocks open pinholes due to the smallest average size of defects. Tailoring a gradual increase of the bias voltage (40/60/80 V) preserves the auto-protection mechanism of droplets and improves the surface finish of the coating.

Mechanical and tribological properties of titanium nitride, zirconium nitride, and (TiN/ZrN)n multilayers were studied to examine the potential of Kelvin probe force microscopy (KPFM) to identify wear mechanisms. Crystalline structure, chemical composition, residual stress, and the mechanical properties showed that the coatings are iso-structural polycrystalline multilayers, with a reduction of grain size, crystallite size, and compressive stress; however, hardness increased with increase in the number of the bilayers. Pin-on-disc test was used for tribological evaluation, and wear tracks were analyzed using field-emission scanning electron microscopy/energy dispersed spectroscopy (FE-SEM/EDS) and KPFM. The increase in mechanical properties generated predominantly abrasive wear mechanisms. Abrasive and adhesive wear mechanisms differentiated by KPFM demonstrated that fragile wear mechanisms presented differences in capacitance and surface potential and that the method is sensitive when the adhered material presents differences in chemical composition. We have demonstrated KPFM to be a promising technique to study tribo-oxidation processes, providing experimental evidence to understand the wear mechanisms at nanometric scales.

Summary Repsol has set up a commitment to achieve net zero emissions by 2050. This decarbonization path would require, initially, Carbon Capture Storage projects; which requires a compulsory subsurface storage. This paper will focus on main lessons learned that have been analyzed from the original Geological Carbon Storage screening process (basin or regional scale), a start up process to qualify potential subsurface candidate for further characterization feasibility analysis. This screening, first step in “Green Exploration”, included as an acceleration driver both depleted oil & gas fields and drilled wells (dry hole/ saline aquifer potential). Main lessons learned are aligned with technical concepts to be considered and specific risk assessment proposal at this project’s phase. It is paramount to align screening results (methodology/deliverables) with mandatory decision process that, if positively qualified, would set up the road map for further visualization to definition methodologies.

Summary Current Upstream decarbonization roadmap would require Carbon Capture Storage projects not just to reduce emissions balance, but to achieve negative emissions. First step in this process of “green exploration”, in analogy with convention exploration, will be to screen out favorable basins. Main objective of this “green exploration” is to analyze (feasibility study) which subsurface options could progress on the project management decision process (Carbon Capture & Storage, CCS subsurface). There are evident advantages in mature Oil & Gas basins where producing fields, close to depletion, aligned with dry hole (potential saline aquifer’s) could speed up screening process feasibility. Based on a prior positive screening a project (depleted Oil & Gas Field) could be sanctioned for next milestone: computed 3D Geological Static model, which will integrate all available Geological, Geophysical & Logging data with required interpretation. This paper summarizes main lessons learned gathered from in-house 3D geological modeling of depleted oil & gas fields and saline aquifers (upside green exploration in shallow producing fields horizons). Mentioned 3D Geological Static model has proven to be the corner stone of any further CO2 storage feasibility analysis and a starting point to explore for additional storage resources, outside producing reservoirs.

Vanadium dioxide (VO2) is widely recognized as a thermochromic material with great potential for application in smart glazing for energy-efficient buildings. The monoclinic (M1) VO2 phase undergoes a first-order reversible phase transition from the semiconductor to the rutile metallic state. In this study, an M1 VO2 porous film was synthesized via a polymer-assisted sol-gel route. Processing parameters, such as drying and reduction temperatures, were varied to evaluate their influence on the thermochromic behavior of VO2 and to determine the necessary trade-off between a significant thermochromic effect and high luminous transmittance. Film-silica glass-film systems with luminous transmittance close to 80% and IR solar modulation ability as large as 20% were prepared. By tracking the optical constants of the films during the thermochromic process, the changes produced at the microscopic level in the material could be correlated with its macroscopic behavior when used as an energy-saving material., Y J. Outon acknowledges the support by the Spanish Ministerio de Educacion y Cultura through grant FPU19-02638. M. Dominguez ac-knowledges the support by the Spanish Ministerio de Ciencia, Innovacion y Universidades under project EQC2018-004704-P. The authors thank the University of Cadiz and IMEYMAT for financing the mutual facilities available at the UCA R&D Central Services (SC-ICYT) and the IMEYMAT Institute project reference PLP2020335-1 respec-tively. The authors also acknowledge J. Gonzalez and F. Delgado for their assistance in the preparation of the STEM specimens.

Hard coatings are continuously improved due to the industrial needs and urgency to reduce the environmental impact of manufacturing processes. For these reasons, scientists seek hard coatings resistant to high mechanical and thermal loads under extreme working conditions (i.e., dry machining), which is why Hf and other rare earth metals have been added to the metastable c-AlxTi(1-x)N nitrides. In the present investigation, Hf-doped c-Al0.64Ti0.36N was deposited in a 2- & 3-axis rotation system using a semi-industrial coater. For this purpose Hf-pins were fixed in Al/Ti targets that produced coatings with ~0.2 at. % Hf-contents homogeneously dispersed. Hf effect on the crystalline state and microstructure, mechanical properties, high-temperature resistance, and the tribological performance of the coating in an Ar-jet at 900 °C were analyzed. It was found that the Hf-doped Al0.64Ti0.36N 5.07 μm thick-layer was mainly cubic fcc + traces of the hcp phases and displayed higher mean hardness (36 GPa) and E-module (416 GPa) than the coating without Hf (h = 32 GPa and E = 402 Pa). The Hf-containing nitride oxidizes dynamically during the high-temperature tribology testing and produces t-Ti2O3 & o-Al2TiO5 after short exposure periods (2.5–5 min), which strongly affected the CoF, before evolving to thermodynamically stable α-Al2O3 & anatase TiO2 between 10 & 30 min in the Ar-flow, thus resulting in the relative stability of the CoF. The mechanical evaluation of the oxidized coatings indicates that a specific oxide thickness must be reached to avoid catastrophic system damage at high normal loads.

The development of homogeneous, dense, and smooth hard coatings is a challenging task, and that is why the high power impulse magnetron sputtering (HiPIMS) method has been proposed to tailor and control the microstructure through the modification of the duty cycle. HiPIMS offers extensive possibilities to obtain good quality films with fine and dense morphology. In this work, the synthesis of CrxN coatings by HiPIMS with the variation of duty cycle (τ = 2.7% and 12%), substrate bias voltages (Vb = −150 and − 250 V), and gas ratio (fN2/Ar = 0.2 and 0.4) was evaluated. The influence of these processing conditions on the chemical composition, microstructure, and adhesion of HiPIMS CrxN was investigated. A significant increment of the deposition rate and the chromium content in the CrxN coatings is observed at τ = 12%; meanwhile, at τ = 2.7%, films showed high nitrogen content. The crystalline phases like α-Cr + h-Cr2N, h-Cr2N, and h-Cr2N + c-CrN were identified in the as-deposited films. The Cr-rich coatings presented faceted columns with cauliflower-like surface morphology, while the growth of the h-Cr2N phase caused a grain size refinement and a denser microstructure. The surface morphology of the h-Cr2N coatings changed from pyramidal to stacked pyramids with the reduction of the duty cycle. The transformation of the h-Cr2N to c-CrN leads to highly dense columnar microstructures with a fine granular morphology and a smooth surface. The duty cycle strategies can be applied to develop a particular microstructure with specific chemical composition and crystallographic phases, resulting in an alternative method to produce graded or multilayer systems. The duty cycle reduction increases the interfacial adhesion strength of the coatings.

An experimental-numerical methodology for failure analysis of the c-Al0.66Ti0.34N/Interface/M2 steel coating system is proposed here. This c-Al0.66Ti0.34N coating was deposited by the arc-PVD technique. The values of the elastic modulus, the fracture energy release rate and the nano-hardness of the coating were obtained by nanoindentation. Normal and shear stress limits of the interface, as well as the adhesive and cohesive critical loads, were measured with the scratch test method. A finite element analysis, using the experimental mechanical properties, was carried out to understand the relationship between the irreversible work vs. depth curve and the mechanical failure evolution of the coating-substrate system, associating the pop-in with nucleation, crack growth and cracking pattern. Extended finite element method (XFEM) was applied for modeling of the mechanical behavior of the coating; the cohesive zones approach was applied for modeling the interface and the Ramberg-Osgood law for modeling the substrate. This approach proposes an experimental-numerical methodology for failure analysis of hard coatings (monolithic body) allowing to calculate fracture energy of the coating material and to model cracking patterns caused by contact mechanics. This work is the first step to answer questions about multi-scale approaches for multi-functional multi-layer coatings to push their enhancements and further applications.

Currently employed in aerospace, defense, oil, and gas applications, Inconel 718 (IN718) is an indispensable alloy with excellent thermo-mechanical properties and hot corrosion resistance. Inconel (IN718) has become the gold standard to manufacture turbine blades, bearing housing parts, compressor seals, drive couple gears, side pocket mandrels, wellheads, packers, and safety valves. Additive Manufacturing (AM) or 3D printing technology is a promising alternative to fabricate and repair nickel-based superalloy components, characterized by challenging processing through conventional methods due to the mechanical strength of the alloys or the geometric complexity of the piece. Furthermore, many applications require surface protection features, such as high hardness, corrosion, and wear resistance. These properties can be achieved by applying hard coatings and/or surface thermochemical treatments such as plasma nitriding. This study reports the effect of plasma nitriding applied on Laser Powder Bed Fusion (LPBF) additively manufactured IN718. Depending on the time, the treatment produced a 1.5–2.8 μm nitrided protective bi-layer composed by an outer CrN containing layer followed by an inner austenitic expanded γN layer. The growing kinetics analysis shows that the nitriding process follows a parabolic behavior. The nitriding process also increases the surface roughness as a result of case hardening formation reaching ~ 60 nm within 2 h. No measurable wear on the plasma nitrided additively manufactured IN718 alloy was recorded.

The presence of critical resonances in microwave power amplifiers has a negative impact on its behavior and performance. These critical resonances are usually predicted from pole-zero stability simulations. In this paper, a different and less demanding approach for the circuit designer is proposed. It is based on performing noise simulations of the amplifier and observing the rise in the noise spectrum that happens when the system has low damping poles. Critical resonance detection is simplified since no additional probes have to be inserted in the circuit and no post-processing for pole-zero analysis is required. The technique is applied to two amplifier prototypes fabricated in microstrip hybrid technology and the results are compared with the conventional pole-zero approach.

This work presents a new technique to cancel third-order intermodulation distortion (IMD3) by using a low frequency injected tone to generate a second-order intermodulation product (IMD2) that fall exactly at the same frequency of the undesired IMD3. The phase and amplitude of the injected tone are controlled to cancel out the IMD3. A proper characterization and a good modeling are needed to demonstrate the concept. Narrow band characterization and modeling of second harmonic (H2) and IMD3 in a Bulk Acoustic Wave (BAW) resonator has been done to evaluate the nonlinear contribution of each material composing the resonator and to identify the dominant nonlinear terms. The concept of this technique will be demonstrated by doing measurements of an on-wafer resonator. The measurement system, including the cancellation procedure, will be described. The cancellation achieved with this technique is in good agreement with the simulations.

FeNi thin films were prepared by magnetron sputtering. A magnetic field of 250 Oe was applied during sample preparation parallel to the substrate surface in order to induce a uniaxial magnetic anisotropy. The film crystallinity and magnetic properties were studied as a function of the deposition rate and material of seed layer (Cu, Cr, Ta, Ti). Detailed analysis of the X-ray diffraction patterns shows no correlation between rate of deposition and grain size, which was deduced using Scherrer's formula. The Ta and Ti seed layers improve the structural features of FeNi films resulting in larger grain size and the development of a strong texture, both of which are favourable for particular sensor applications. Large grain size increases the angular dispersion of magnetic anisotropy.

Wildcat Creek, a tributary to the Wabash River, was identified by the USDA Natural Resources Conservation Service (NRCS) as a priority watershed for its high sediment and nutrient loading contributions to the Mississippi River. As part of the Mississippi River Basin Initiative (MRBI), the incorporation of conservation practices was implemented through a Cooperative Conservation Partnership Initiative (CCPI) agreement using existing USDA programs. The objective of this work was to evaluate the potential water quality benefits of conservation practices placed in the Wildcat Creek Watershed through the MRBI-CCPI. Specifically, seven output variables (surface runoff, tile flow, sediments, total phosphorus [P], soluble P, soluble nitrogen [N], and soluble N in tile) were compared for four different row crop conservation practices (residue and tillage management no-till, residue and tillage management mulch-till, cover crops, and forage and biomass planting), and two manure application scenarios. Using the Agricultural Policy/Environmental eXtender (APEX) model, calibrated and validated for a field within the St. Joseph River Watershed, a modeling assessment was developed for current conservation practices incorporated at a similar watershed, Wildcat Creek. Annual average values were estimated for each simulated scenario, and percentage reductions were reported. Cover crops consistently reduced sediment and nutrient loads in runoff by more than 50% compared to the tillage baseline scenario, and removal of the manure application in the waste utilization scenario reduced the predicted total and soluble P amounts by 75% and 92%, respectively. When extrapolating the edge-of-field values predicted by the model to the area occupied by each conservation practice throughout the duration of the contracts at the Wildcat Creek Watershed, the total reductions were estimated to be almost 7,000 Mg (7,700 tn) of sediment (68% decrease), 20,000 kg (44,092 lb) of total P (73% decrease), 4,000 kg (8,818.5 lb) of soluble N in runoff (50% decrease), and 185,000 kg (414,00 lb) of soluble N in tile flow (43% decrease). Agricultural Policy/Environmental eXtender modeling is a useful tool for predicting sediment and nutrient loading information at the field-scale, which can be used to calculate the relative impact of conservation practices at the watershed scale when monitoring data are not available. The modeling results confirm the positive impact of these conservation practices and of the MRBI-CCPI initiative at improving water quality at the edge-of-field, and potentially at the Wildcat Creek, the Greater Wabash River Basins, and ultimately the Mississippi River Basin.

A techno-economic analysis of a natural gas combined cycle (NGCC) integrated with MEA-based CO 2 capture with an advanced configuration is carried out. Sequential supplementary firing in the Heat Recovery Steam Generator (HRSG) is combined with a supercritical combined cycle for the purpose of increasing CO 2 production for Enhanced Oil Recovery (EOR) at a competitive levelised cost of electricity. Supercritical steam conditions with a double reheat in the steam cycle are used to largely improve performance and take full advantage of sequential supplementary firing in the HRSG. Sequential supplementary firing increases the flue gas temperature throughout the Heat Recovery Steam Generator (HRSG) by burning additional fuel at different stages to maximise the use of oxygen available in the flue gas exiting the gas turbine. The positive impact on the post combustion capture plant size and energy requirements for solvent regeneration are attractive for markets with cheap natural gas, and where the emphasis on capital cost reduction is important. This study then investigates the effect of fuel prices and capital costs for this configuration and compares it with a typical combined cycle integrated with MEA-based CO 2 capture. A case study for Mexico is presented, at a range of gas prices where these modifications would be attractive, with a tentative target of $40/tCO 2 .

Intra Ordovician interpretation has been historically one of the main pitfalls in Murzuq Basin, even when tracing different lithological units and/or lateral facies change in areas with dense well control. Seismic attributes provide a useful tool to characterize reservoirs because they transform seismic amplitudes into elastic properties , which are related with facies and petrophysical properties. Seismic and well log data are integrated and geological interpretation can be done in seismic attributes domain. In our case of study, pre-stack seismic inversion results, P-wave impedance and Vp/Vs ratio supported a conceptual geological model for Murzuq Basin (Libya) main reservoir. P-wave impedance helped to separate facies and sedimentary environments in a very complex glaciogenic Upper Ordovician reservoir. Vp/Vs ratio delimited sandstone bodies related with advance and retreat of the glacial ice in the area. Both seismic volumes matched very well with log data and they helped to define the northern stratigraphic closure of the reservoir.

Summary Within the prolific NC115-NC186 blocks located in Murzuq Basin (Libya), Rompetrol and Repsol operators reached a historic exploration success, with several giant fields discovered. During the last 10 years, the exploratory success rate has been decreasing, with more than 20 dry exploratory wells focused on classic trapping styles (4 way dip closures/3 way fault related). This evidence opened the possibility to develop stratigraphic exploration concepts for a proper investigation of the permits. Seismic interpretation/attributes, depth/isopach maps, core and well log data were integrated in order to build sedimentological & paleoenviromental models that can be used both as an approach for searching for stratigraphic traps and for prospect de risking tool.

A metamaterial spacer composed of spiral resonators (SRs) and narrow metal strips has been tested to operate like a bidirectional artificial magnetic conductor (AMC) reflector at 2.45 GHz. The performance of the spacer has also been evaluated in a closely spaced multiple-antenna system applied to successfully increase the transmission capacity of a commercial wireless IEEE 802.11b router.

The use of a low profile, light weight and easy to fabricate transpolarising surface placed on one side of a trihedral corner reflector (TCR) as polarimetric calibrator is presented in this letter. The transpolarising-TCR (TTCR) presents a high backscattered cross-polar response contrary to standard TCRs. The performance of this device has been tested at X-band using the UPC GB-SAR., Comment: Accepted for publication in IEEE Geoscience and Remote Sensing Letters

The objective of this research was to evaluate the quality and shelf life of meat from pigs given dietary supplementation of natural astaxanthin. Pigs were fed either a control diet or the same diet supplemented with 66.7 mg/kg of natural astaxanthin for 42 d. Astaxanthin supplementation had no affect (P ≥ 0.117) on growth performance or ham and loin lean quality at fabrication. Loin chops from pigs supplemented with dietary astaxanthin were darker (P < 0.002) and less yellow (P = 0.006) than loin chops from control pigs during 7 d of retail display. Ground patties from picnic shoulders of pigs supplemented with dietary astaxanthin were darker (P < 0.001) and more red (P < 0.001) than ground patties from control pigs during 7 d of retail display. This initial experiment documents the viability of dietary astaxanthin supplementation as a method to improve shelf life of pork products.

A metamaterial spacer to decorrelate two closely spaced antennas has been designed and tested. The metamaterial spacer exhibits an artificial magnetic conductor (AMC) behavior around 2.6 GHz. Its performance has been checked against a simple metal spacer (PEC), providing a quasi orthogonal radiation pattern and good results in terms of decoupling and decorrelating a two-antenna system. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1414–1417, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23365

Metamaterial slabs made of magnetic resonators (artificial magnetic conductor, AMC surfaces) can provide unusual electromagnetic properties, such as the dual PMC/PEC behavior, when used as reflectors. This property has been assessed and tested with the design and fabrication of a one-layer spiral AMC slab. Moreover, two bidirectional AMC surfaces have also been designed and measured. These structures, composed of spiral (SR) or capacitive loaded loop (CLL) resonators printed on dielectric strips, can provide 0° reflection coefficient phase when the incident electric field wave impinges on any side. A very low electrical thickness is achieved. Compact antenna systems with two (or more) close isolated antennas can be designed with such structures. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 1949–1953, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22567

Lessons Learned presented herewith could be summarized as Knowledge gained through the solution to a problem that has been implemented and proven to be effective. In this case predrilling Formation Evaluation challenges in this frontier exploration region (Iraqi Kurdistan) differed from execution phase requirements. Solutions provided and execution issues to cope with the real Formation Evaluation challenges are presented herewith, as a start up for discussion. It is worth noting that Pre/drilling scouting concerning available technology in country helped to define required Formation Evaluation program and provide flexibility, even with an active contract, to mobilize required tools. Low Porosity Fractured Carbonate presents several challenges from data acquisition and Formation Evaluation point of view. Experience gained during the drilling campaign demonstrated that: a. Error tolerance in porosity evaluation is very low. - Diversified porosity data acquisition, epithermal neutron and Nuclear Magnetic Resonance, was paramount for enhanced porosity evaluation. The former was less affected by borehole environment and the latter is independent from lithology and pore space hydrogen. - Accurate knowledge of reservoir mineralogy to minimize impact of any kind of anhydrite content. Induce Gamma Spectroscopy, even without chemical radioactive source, was a useful technology. b. Sub hydrostatic reservoir conditions. Even though just minor losses occurred, wireline logging pressure data demonstrated that the reservoir was sub-hydrostatic. Lessons learned in this region demonstrates that even under this circumstances (sub hydrostatic carbonate reservoirs) wireline logging pressure data is able to provide accurate fluid gradient even in low motilities scenario. Accurate stations selection, variable fluid chamber tool and exploration boldness proved to be paramount. c. Formation Evaluation workflow (technology in country) helped to define final logging acquisition program and cope with operating program modifications. Fracture analysis from Electrical Borehole Images and Full Waveform Acoustic tools was also integrated for reservoir summation inputs.

Prefractal Hilbert curves are analyzed in terms of radiation efficiency, quality factor, and electrical size for their use as small self-resonant monopole antennas. The structures show better performance as loads of monopoles than as radiating structures. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 45–49, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11122

The performance of space-filling curves used as small antennas is evaluated in terms of quality factor and radiation efficiency. The influence of their topology is also considered. Although the potential use of these curves is for antenna miniaturization, their behavior is not exceptional when compared with other intuitively generated antennas.

A multi-objective genetic algorithm (GA) has been applied in conjunction with the numerical electromagnetic code (NEC) to the optimization of wire pre-fractal Koch-like antennas in terms of bandwidth, efficiency, and electrical size. Their performance is compared to that of other nonfractal designs.

Cryopreservation of islets of Langerhans is a necessary procedure since human pancreatic islet transplantation has become a reality for the clinical treatment of Type I, insulin-dependent diabetes mellitus. Although successful cryopreservation of rodent and human islets is a well-established technique for islet storage after isolation and purification, little is known about the influence of the freeze-thaw procedure on the islets' potential to induce angiogenesis and revascularization, a major process necessary for the viability of grafted cells. In this study, the revascularization process of cryopreserved islets transplanted in the liver and in the renal subcapsular space of diabetic and nondiabetic rats is analyzed by a double indirect immunofluorescence technique. Frozen-thawed pancreatic islets were cooled slowly to -40 degrees C, stored at -196 degrees C, and thawed rapidly. Lewis rat were grafted with either Lewis (isografts) or Wistar (allografts) overnight-cultured and frozen-thawed islets obtained by collagenase digestion. Rats were killed different days after implantation, and the livers and kidneys bearing the grafted islets were snap-frozen and immunohistochemically stained with a double immunofluorescence technique using a rabbit anti-factor VIII antiserum (which labels endothelial cells) and a guinea pig anti-insulin antibody. Overnight-cultured islet grafts completed revascularization by Days 4-7 after transplantation, as shown by the detection of endothelial cells within and surrounding the islets. The identical staining pattern of revascularization was observed in islets frozen-thawed before transplantation. It is concluded that islet cryopreservation is a suitable technique for long-term storage prior to transplantation since it does not interfere with the neovascularization process of islet grafts.

Background Hepatoerythropoietic porphyria (HEP) is a rare form of porphyria that results from a deficiency of uroporphyrinogen decarboxylase (UROD). The disease is caused by homoallelism or heteroallelism for mutations in the UROD gene.

Even though much progress has been made towards understanding the molecular nature of glioma, the survival rates of patients affected by this tumour have not changed significantly over recent years. Better knowledge of this malignancy is still needed in order to predict its outcome and improve patient treatment. VAV1 is an GDP/GTP exchange factor for Rho/Rac proteins with oncogenic potential that is involved in the regulation of cytoskeletal dynamics and cell migration. Here we report its overexpression in 59 patients diagnosed with high-grade glioma, and the associated upregulation of a number of genes coding for proteins also involved in cell invasion- and migration-related processes. Unexpectedly, immunohistochemical experiments revealed that VAV1 is not expressed in glioma cells. Instead, VAV1 is found in non-tumoural astrocyte-like cells that are located either peritumouraly or perivascularly. We propose that the expression of VAV1 is linked to synergistic signalling cross-talk between cancer and infiltrating cells. Interestingly, we show that the pattern of expression of VAV1 could have a role in the neoplastic process in glioblastoma tumours.

The use of a transpolarizing surface placed on one side of a trihedral corner reflector (TCR) as polarimetric calibrator is presented in this paper. The transpolarizing-TCR presents a high back-scattered cross-polar response. This structure has been tested at 9.65 GHz (X-band) with the help of the UPC GB-SAR system.

Conventional antenna radiation efficiency measurement techniques, such as the Wheeler cap, are generally narrow-band and, thus, well suited for resonant antennas. In this work, the Johnston-Geissler (J-G) method based on the Wheeler cap principle is used in a wide frequency range. First, a good agreement between measurement and simulation in an ultrawide frequency band is shown on a straight wire monopole antenna with different attenuators emulating antenna losses. Then, this technique is used to measure the radiation efficiency of several ultrawideband (UWB) antennas.

The processing of potato products from fresh potatoes produces waste effluent containing substantial amounts of protein. In this study, the recovery of a protein-hydrocolloid complex from a simulated potato processing plant waste effluent (SPWE), using carboxymethylcellulose (CMC) as the complexing agent, was investigated. The effects of CMC to protein ratio (CPR), pH, temperature and type of CMC with respect to degree of substitution (DS) on complex formation and protein recovery were studied. Optimum results were obtained using CMC DS 0.85–0.95, CPR of 0.05, and pH 1.5–4.0. The temperature of precipitation had little effect in the range of 4–25°C. The recovered complex contained 76.6% protein, 17.6% CMC and formed a bulky precipitate easily separated from the SPWE.

A new integrated numerical approach for simulation of fast and slow relaxation in magnets has been developed. It is based on Monte Carlo calculations which additionally take into account important dynamic information provided by the Langevin dynamics method. Real time quantification of Monte Carlo steps has been achieved by the new technique for a simple one-dimensional modelled system of interacting spins.