A novel two-stage technology combining vacuum electro-spark alloying (VESA) and pulsed cathodic arc evaporation (PCAE) was approbated for the deposition of TiC-based coatings in inert (Ar) and ...reactive (C
H
) atmospheres. The deposition was carried out using a TiC-NiCr-Eu
O
electrode and 5140 steel substrates. Structural, elemental, and phase compositions of the deposited coatings were investigated by scanning electron microscopy, energy-dispersive spectrometry, and X-ray diffraction. The mechanical properties of the coatings were measured by nanoindentation using a 4 mN load. The tribological properties of the coatings were measured using the pin-on-disc setup in air and in distilled water at a 5 N load. The experimental data suggest that VESA coatings are characterized by surface defects, a hardness of 12.2 GPa, and a friction coefficient of 0.4. To ensure good adhesion between the VESA coating and the upper layer containing diamond-like carbon (DLC), an intermediate layer was deposited by PCAE in the Ar atmosphere. The intermediate layer had a hardness of up to 31 GPa. The upper layer of the coating ensured a low and stable friction coefficient of 0.2 and high wear resistance due to the formation of an sp
-sp
bound carbon phase. Multilayer TiC-based coating with the upper DLC layer, in addition to high tribological properties, was characterized by the lowest corrosion current density (12 μА/cm
).
This paper presents recent advances in screen content video coding, with an emphasis on two state-of-the-art standards: HEVC/H.265 Screen Content Coding Extensions (HEVC-SCC) by ISO/IEC Moving ...Picture Experts Group and ITU-T Video Coding Experts Group, and Display Stream Compression (DSC) by Video Electronics Standards Association. The HEVC-SCC enhances the capabilities of HEVC in coding screen content, while DSC provides lightweight compression for display links. Although targeting different application domains, they share some design principles and are expected to become the leading formats in the marketplace in the coming years. This paper provides a brief account of their background, key elements, performance, and complexity characteristics, according to their final specifications. As we survey these standards, we also summarize prior arts in the last decade and explore future research opportunities and standards developments in order to give a comprehensive overview of this field.
The aim of this paper was to examine the satisfaction of voluntourists derived from various aspects of their trip. Framed within the Existence, Relatedness and Growth Theory, the paper examines ...volunteers’ motivations, expectations and satisfaction based on their financial and time investment volunteering with Volunteer Eco Students Abroad (VESA), the intereactions they had on the trip, and the extent to which travellers felt as though they contributed to community goals. In 2012, the researchers carried out in-depth, semi-structured interviews with 16 Canadian voluntourists following their time in St. Lucia, South Africa. A thematic analysis was used to interpret the data, resulting in three themes: ‘Evaluating Investment’, ‘Contribution to Community’ and ‘Opportunities and Reaffirmations’; sub-themes were matched with aspects of Existence, Relatedness and Growth Theory. Findings elicited several levels of expectations of voluntourists revealed through their feelings of satisfaction or dissatisfaction. On the lowest level, voluntourists expect adequate food and water whilst volunteering. Informants highlighted the various ways they raised fund for the trip, and this impacted their level of accountability for contributing to the community. Volunteers also expect volunteer organizations to be transparent regarding the use of funds and expressed dissatisfaction when this did not occur. Volunteers anticipated a feeling of connection between the hosts and themselves and were frustrated if they felt more time could have been allotted to working with community residents. Lastly, informants expected the experience to provide an opportunity for self-learning and professional development and overall were satisfied with this element of the trip.
Bovine babesiosis is an acute and persistent tick-borne global disease caused mainly by the intraerythrocytic apicomplexan parasites
and
.
infected erythrocytes sequester in blood capillaries of the ...host (cytoadhesion), causing malaria-like neurological signs. Cytoadhesion and antigenic variation in
are linked to the expression of members of the Variant Erythrocyte Surface Antigen (VESA) gene family. Animals that survive acute
infection and those vaccinated with attenuated strains remain persistently infected, suggesting that
parasites use immune escape mechanisms. However, attenuated
parasites do not cause neurological signs in vaccinated animals, indicating that virulence or attenuation factors play roles in modulating parasite virulence phenotypes. Artificial overexpression of the SBP2t11 protein, a defined attenuation factor, was associated with reduced cytoadhesion, suggesting a role for this protein as a key modulator of virulence in the parasite. Hereby, we propose a model that might be functional in the modulation of
virulence and persistence that relies on the interplay among SBP2t, VESA proteins, cytoadhesion, and the immune responses of the host. Elucidation of mechanisms used by the parasite to establish persistent infection will likely contribute to the design of new methods for the control of bovine babesiosis.
Investigation of the population dynamics of pathogens contributes to a better understanding of disease transmission. Herein, the extent of Babesia bovis genotypic strain diversity within a defined ...cohort is reported.
Multiple genetically distinct strains of a pathogen circulate and compete for dominance within populations of animal reservoir hosts. Understanding the basis for genotypic strain structure is critical for predicting how pathogens respond to selective pressures and how shifts in pathogen population structure can lead to disease outbreaks. Evidence from related Apicomplexans such as Plasmodium, Toxoplasma, Cryptosporidium and Theileria suggests that various patterns of population dynamics exist, including but not limited to clonal, oligoclonal, panmictic and epidemic genotypic strain structures. In Babesia bovis, genetic diversity of variable merozoite surface antigen (VMSA) genes has been associated with disease outbreaks, including in previously vaccinated animals. However, the extent of VMSA diversity within a defined population in an endemic area has not been examined. We analyzed genotypic diversity and temporal change of MSA-1, a member of the VMSA family, in individual infected animals within a reservoir host population. Twenty-eight distinct MSA-1 genotypes were identified within the herd. All genotypically distinct MSA-1 sequences clustered into three groups based on sequence similarity. Two thirds of the animals tested changed their dominant MSA-1 genotypes during a 6-month period. Five animals within the population contained multiple genotypes. Interestingly, the predominant genotypes within those five animals also changed over the 6-month sampling period, suggesting ongoing transmission or emergence of variant MSA-1 genotypes within the herd. This study demonstrated an unexpected level of diversity for a single copy gene in a haploid genome, and illustrates the dynamic genotype structure of B. bovis within an individual animal in an endemic region. Co-infection with multiple diverse MSA-1 genotypes provides a basis for more extensive genotypic shifts that characterizes outbreak strains.
A clock and data recovery (CDR) for the physical layer of DisplayPort at sink side is described. A 1/5-rate linear phase detector (PD) compares the phase of the incoming data with that of sampling ...clock to recover a clean clock and data. A pattern based frequency detector (PBFD) reduces frequency error to be in the pullin-range of the 1/5-rate linear PD. The PBFD reduces the frequency error down to 3.2% before the linear PD starts its operation. The CDR implemented in a 0.13 m CMOS process shows 29-ps rms and 154-ps peak-to-peak jitter in the recovered clock and 10 -7 bit error rate (BER) for 2 31 -1 pseudorandom binary-sequence (PRBS) input while consuming 87mW from a 1.2-V supply.
A 1.62/2.7-Gb/s adaptive transmitter with two-tap preemphasis is presented. The tap coefficients are adjusted by detecting the propagation time through the channel with different lengths. This ...adaptive transmitter is fabricated in 0.13-¿m CMOS technology, and the core area occupies 0.25 × 0.15 mm 2 . The maximum power consumption from a 1.2-V supply is 32.4 mW at 2.7 Gb/s. For a 40-in FR4 PCB trace with a 12.3-dB loss, the measured RMS and peak-to-peak jitters of the recovered data are 30 and 231 ps, respectively, for a 1.62-Gb/s pseudorandom binary sequence (PRBS) of 2 31 - 1. For a 20-in FR4 PCB trace with a 10.6-dB loss, the RMS and peak-to-peak jitters are 21 and 144 ps, respectively, for a 2.7-Gb/s PRBS of 2 31 - 1. For both cases, the measured bit error rates are less than 10 -12 .
Airbus has prepared a methodology to assess the severity of a Wake Vortex Encounter (WVE). This methodology is called Vortex Encounter Severity Assessment (VESA). VESA makes it possible to compare ...the effect of wake vortices generated by different aircraft on an aircraft that encounters such a vortex.
Important elements of VESA are the hazard criteria that rate particular aircraft reactions during WVEs. Hazard criteria are necessary to compare WVEs in batch simulations. This paper describes how piloted flight simulations for WVE investigations during landing approach were prepared and how the results were used for hazard criteria development. This work was part of the European S-WAKE program.
Airbus hat eine Methodik entwickelt, mit der die Heftigkeit des Fluges durch eine Wirbelschleppe bewertet werden kann. Diese Methodik heißt “Vortex Encounter Severity Assessment” (VESA). VESA ermöglicht einen Vergleich der Wirbelschleppen unterschiedlicher Flugzeuge in ihren Auswirkungen auf ein Flugzeug, das diese Wirbelschleppe durchfliegt.
Wesentliche Elemente von VESA sind die Gefährdungskriterien, die spezielle Flugzeugreaktionen während des Wirbelschleppendurchfluges bewerten. Solche Gefährdungskriterien sind notwendig, um verschiedene Durchflüge in Nicht-Echtzeit-Simulationen vergleichen zu können. Dieser Artikel beschreibt, wie Echtzeit-Flugsimulationen mit Piloten für die Untersuchung von Wirbelschleppendurchflügen im Landeanflug vorbereitet wurden und wie die Ergebnisse verwendet wurden, um Gefährdungskriterien zu entwickeln.
The importance of video compression technology is highly emphasized according to the advancement of display technology which plays a crucial role in many industries. Video compression technology is ...important in the aspect of reducing bandwidth usage, optimizing storage space, and enhancing the efficiency of data transmission. Video Electronics Standards Association (VESA) Display Compression-M (VDC-M) video compression standard 1, as released by the VESA, shows high compression ratio and high performance. In this paper, we propose a hardware architecture for transform entropy decoding which supports the VDC-M standard. It can extract and align quantized coefficients which are transmitted from encoder to decoder for reconstruction. The utilization of optimized entropy coding techniques enhances the overall performance, making the proposed hardware architecture contribute to advanced video compression in modern display technologies.
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