495 research outputs found
Risk factors for Salmonella, Shiga toxin-producing Escherichia coli and Campylobacter occurrence in primary production of leafy greens and strawberries
The microbiological sanitary quality and safety of leafy greens and strawberries were assessed in the primary production in Belgium, Brazil, Egypt, Norway and Spain by enumeration of Escherichia coli and detection of Salmonella, Shiga toxin-producing E. coli (STEC) and Campylobacter. Water samples were more prone to containing pathogens (54 positives out of 950 analyses) than soil (16/1186) and produce on the field (18/977 for leafy greens and 5/402 for strawberries). The prevalence of pathogens also varied markedly according to the sampling region. Flooding of fields increased the risk considerably, with odds ratio (OR) 10.9 for Salmonella and 7.0 for STEC. A significant association between elevated numbers of generic E. coli and detection of pathogens (OR of 2.3 for STEC and 2.7 for Salmonella) was established. Generic E. coli was found to be a suitable index organism for Salmonella and STEC, but to a lesser extent for Campylobacter. Guidelines on frequency of sampling and threshold values for E. coli in irrigation water may differ from region to region
Partial discharges location in power transformers using piezoceramic sensors
The detection and the spatial localization of partial discharges in high-voltage electrical machines are considered as an effective method in predictive maintenance that can provide valuable information on the health of the insulation system and allow to determine accurately the location of the risky insulation elements, which in turn will avoid any premature equipment’s deterioration by scheduling preventive maintenance action. After confirming in a previous published paper the efficiency of a new generation of piezoceramics sensors (high temperature ultrasonic transducers) to detect and characterize partial discharges, we are going to investigate, in this work, a second potential of this technology to locate the partial discharge sources by relying on its ability to detect acoustic signals emitted by partial discharge sources. We will present experimental results, demonstrating the effectiveness of these sensors to locate partial discharges sources and, we will also present an algorithm for calculating the partial discharge foci, based on the acoustic wave flight time
Komposisi Jenis Dan Potensi Ancaman Tumbuhan Asing Invasif Di Taman Nasional Gunung Halimun-salak, Jawa Barat [Species Composition and Threat Potential of Invasive Plants Species in Gunung Halimun-salak National Park, West Java]
A study on species composition and threat potential of invasive plant species was conducted in the Gunung Halimun-Salak National Park,Cidahu Resort, West Java. We developed two plots of different altitudes. The result showed that there were four invasive alien species possessing potential threat to the ecosystem and native species in the National Park, i.e. Piper aduncum (Piperaceae, with an Important Value of 20,70); Calliandra calothyrsus (Mimosaceae, IV = 9,11), Austroeupatorium inulaefolium (Asteraceae, IV = 18,77), and Clidemia hirta (Melastomataceae) as shrub. The threats of invasive plants happen in open forest area and could occur from the residential or public places
Quantum phase transitions in photonic cavities with two-level systems
Systems of coupled photonic cavities have been predicted to exhibit quantum
phase transitions by analogy with the Hubbard model. To this end, we have
studied topologies of few (up to six) photonic cavities each containing a
single two-level system. Quantum phase space diagrams are produced for these
systems, and compared to mean-field results. We also consider finite effective
temperature, and compare this to the notion of disorder. We find the extent of
the Mott lobes shrink analogously to the conventional Bose-Hubbard model.Comment: 11 pages, 11 figures, updated typo
Phonitons as a sound-based analogue of cavity quantum electrodynamics
A quantum mechanical superposition of a long-lived, localized phonon and a
matter excitation is described. We identify a realization in strained silicon:
a low-lying donor transition (P or Li) driven solely by acoustic phonons at
wavelengths where high-Q phonon cavities can be built. This phonon-matter
resonance is shown to enter the strongly coupled regime where the "vacuum" Rabi
frequency exceeds the spontaneous phonon emission into non-cavity modes, phonon
leakage from the cavity, and phonon anharmonicity and scattering. We introduce
a micropillar distributed Bragg reflector Si/Ge cavity, where Q=10^5-10^6 and
mode volumes V<=25*lambda^3 are reachable. These results indicate that single
or many-body devices based on these systems are experimentally realizable.Comment: Published PRL version. Note that the previous arXiv version has more
commentary, figures, etc. Also see http://research.tahan.com
Indonesian National Defense Strategy in the Asean Region of the 21st Century Based on Defense System and Security Population Demography
Given its strategic position between the Indian and Pacific Oceans, Indonesia has a very significant strategic interest and role in shaping the ASEAN Region. The proximity of Indonesia's position to one of the main conflict flashpoints in the ASEAN Region, namely the South China Sea (LCS), makes Indonesia vulnerable to spillover effects arising from various possible incidents and conflicts in the region. To safeguard its interests, Indonesia must be able to play its strategic role in ensuring a stable, safe and peaceful ASEAN Region during conflicts of interest of other countries in the region. To advance Indonesia's national interests in the region, diplomatic steps taken by Indonesia must be complemented and supported by strategic steps in the defense sector. Indonesia has long adhered to the Total People's Defense and Security System (the Universal People's Defense and Security System, hereinafter referred to as Sishankamrata) as the basis of its national defense policy. Sishankamrata contains core values ​​and principles that guide the formulation and implementation of Indonesia's national defense policy. Sishankamrata is embodied in the doctrine, strategy, and posture of Indonesia's national defense As a strategic defense concept, Sishankamrata must remain relevant and suitable to deal with a volatile, uncertain, complex, and ambiguous strategic environment (VUCA), while at the same time contributing to the advancement of Indonesia's national interests
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