263 research outputs found

    An FPGA-based real-time event sampler

    Get PDF
    This paper presents the design and FPGA-implementation of a sampler that is suited for sampling real-time events in embedded systems. Such sampling is useful, for example, to test whether real-time events are handled in time on such systems. By designing and implementing the sampler as a logic analyzer on an FPGA, several design parameters can be explored and easily modified to match the behavior of different kinds of embedded systems. Moreover, the trade-off between price and performance becomes easy, as it mainly exists of choosing the appropriate type and speed grade of an FPGA family

    Characterization of CMR5c and CMR12a, novel fluorescent Pseudomonas strains from the cocoyam rhizosphere with biocontrol activity

    Get PDF
    Aim: To screen for novel antagonistic Pseudomonas strains producing both phenazines and biosurfactants that are as effective as Pseudomonas aeruginosa PNA1 in the biocontrol of cocoyam root rot caused by Pythium myriotylum. Material and Results: Forty pseudomonads were isolated from the rhizosphere of healthy white and red cocoyam plants appearing in natural, heavily infested fields in Cameroon. In vitro tests demonstrated that Py. myriotylum antagonists could be retrieved from the red cocoyam rhizosphere. Except for one isolate, all antagonistic isolates produced phenazines. Results from whole-cell protein profiling showed that the antagonistic isolates are different from other isolated pseudomonads, while BOX-PCR revealed high genomic similarity among them. 16S rDNA sequencing of two representative strains within this group of antagonists confirmed their relatively low similarity with validly described Pseudomonas species. These antagonists are thus provisionally labelled as unidentified Pseudomonas strains. Among the antagonists, Pseudomonas CMR5c and CMR12a were selected because of their combined production of phenazines and biosurfactants. For strain CMR5c also, production of pyrrolnitrin and pyoluteorin was demonstrated. Both CMR5c and CMR12a showed excellent in vivo biocontrol activity against Py. myriotylum to a similar level as Ps. aeruginosa PNA1. Conclusion: Pseudomonas CMR5c and CMR12a were identified as novel and promising biocontrol agents of Py. myriotylum on cocoyam, producing an arsenal of antagonistic metabolites. Significance and Impact of the Study: Present study reports the identification of two newly isolated fluorescent Pseudomonas strains that can replace the opportunistic human pathogen Ps. aeruginosa PNA1 in the biocontrol of cocoyam root rot and could be taken into account for the suppression of many plant pathogens

    Growing media constituents determine the microbial nitrogen conversions in organic growing media for horticulture

    Get PDF
    Vegetables and fruits are an important part of a healthy food diet, however, the eco-sustainability of the production of these can still be significantly improved. European farmers and consumers spend an estimated Euro15.5 billion per year on inorganic fertilizers and the production of N-fertilizers results in a high carbon footprint. We investigated if fertilizer type and medium constituents determine microbial nitrogen conversions in organic growing media and can be used as a next step towards a more sustainable horticulture. We demonstrated that growing media constituents showed differences in urea hydrolysis, ammonia and nitrite oxidation and in carbon dioxide respiration rate. Interestingly, mixing of the growing media constituents resulted in a stimulation of the function of the microorganisms. The use of organic fertilizer resulted in an increase in amoA gene copy number by factor 100 compared to inorganic fertilizers. Our results support our hypothesis that the activity of the functional microbial community with respect to nitrogen turnover in an organic growing medium can be improved by selecting and mixing the appropriate growing media components with each other. These findings contribute to the understanding of the functional microbial community in growing media and its potential role towards a more responsible horticulture

    A Performance Comparison between Enlightenment and Emulation in Microsoft Hyper-V

    Get PDF
    Microsoft MS Hyper-V is a native hypervisor that enables platform virtualization on x86-64 systems It is a microkernelized hypervisor where a host operating system provides the drivers for the hardware This approach leverages MS Hyper-V to support enlightenments the Microsoft name for Paravirtualization in addition to the hardware emulation virtualization technique This paper provides a quantitative performance comparison using different tests and scenarios between enlightened and emulated Virtual Machines VMs hosted by MS Hyper-V server 2012 The experimental results show that MS enlightenments improve performance by a factor of more than tw

    RTS hypervisor qualification for real-time systems

    Get PDF
    Virtualization is a synonym for the server and cloud computing arena. Recently, it started to be also applied to real-time embedded systems with timing constraints. However, virtualization products for data centers and desktop computing cannot be readily applied to embedded systems because of differences in requirements, use cases, and computer architecture. Bridging the gap between virtualization and real-time requirements imposes the need of real-time virtualization products. Therefore, some embedded software manufacturers have built several real-time hypervisors specialized for embedded systems. Currently, there are several commercial ones such as Greenhills INTEGRITY MultiVisor, Real-Time Systems (RTS) GmbH Hypervisor, Tenasys eVM for Windows, National Instruments Real-Time Hyper Hypervisor, and some others. This paper provides the behavior and performance results of evaluating RTS hypervisor and gives advices of its use for soft or hard real-time embedded systems

    Real-time capabilities in the standard Linux Kernel: How to enable and use them?

    Get PDF
    Linux was originally designed as a general purpose operating system without consideration for real-time applications. Recently, it has become more attractive to the real-time community due to its low cost and open source approach. In order to help the real-time community, we will present in this paper the practical steps required to achieve a real-time Linux by applying the PREEMPT-RT patches which will provide Linux with these capabilities. We will also focus on some of the kernel configuration that should get attention while building the kernel in order to maintain the real-time behavior of the system during runtime. DOI: 10.17762/ijritcc2321-8169.15012
    corecore