2,084 research outputs found

    Surface conditions of the Orgueil meteorite parent body as indicated by mineral associations

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    Three periods of mineral formation from study of Orgueil meteorit

    A chondrule in the Chainpur meteorite

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    Glass occurrence in chondrules as evidence for formation by rapid cooling of liquid droplets - chondritic meteorite

    Investigation of the fine structure in the 2 D sequence of sodium using level-crossing spectroscopy

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    Splittings in the n 2 D sequence were measured for n=4-9. An accuracy of about 0.1% was obtained in level-crossing measurements on an atomic beam. The D states were populated by step-wise excitation, using an RF lamp and a CW dye laser. A method for measuring the sign of the spin-orbit coupling constant is demonstrated. With the present measurements, the highly anomalous n 2 D sequence in sodium has now been studied for n=3-16

    A mobile system for active otpical pollution monitoring

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    The remote monitoring of atmospheric pollutants can now be performed in several ways. Laser radar techniques have proven their ability to reveal the spatial distribution of different species or particles. Classical optical techniques can also be used, but yield the average concentration over a given path and hence no range resolution. One such technique is Differential Optical Absorption Spectroscopy, DOAS. Such schemes can be used to monitor paths that a preliminary lidar investigation has shown to be of interest. Having previously had access to a mobile lidar system, a new system has been completed. The construction builds on experience from using the other system and it is meant to be more of a mobile optical laboratory than just a lidar system. A complete system description is given along with some preliminary usage. Future uses are contemplated

    Fast Searching in Packed Strings

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    Given strings PP and QQ the (exact) string matching problem is to find all positions of substrings in QQ matching PP. The classical Knuth-Morris-Pratt algorithm [SIAM J. Comput., 1977] solves the string matching problem in linear time which is optimal if we can only read one character at the time. However, most strings are stored in a computer in a packed representation with several characters in a single word, giving us the opportunity to read multiple characters simultaneously. In this paper we study the worst-case complexity of string matching on strings given in packed representation. Let mnm \leq n be the lengths PP and QQ, respectively, and let σ\sigma denote the size of the alphabet. On a standard unit-cost word-RAM with logarithmic word size we present an algorithm using time O\left(\frac{n}{\log_\sigma n} + m + \occ\right). Here \occ is the number of occurrences of PP in QQ. For m=o(n)m = o(n) this improves the O(n)O(n) bound of the Knuth-Morris-Pratt algorithm. Furthermore, if m=O(n/logσn)m = O(n/\log_\sigma n) our algorithm is optimal since any algorithm must spend at least \Omega(\frac{(n+m)\log \sigma}{\log n} + \occ) = \Omega(\frac{n}{\log_\sigma n} + \occ) time to read the input and report all occurrences. The result is obtained by a novel automaton construction based on the Knuth-Morris-Pratt algorithm combined with a new compact representation of subautomata allowing an optimal tabulation-based simulation.Comment: To appear in Journal of Discrete Algorithms. Special Issue on CPM 200

    Compliance in own-check systems poses challenges in small-scale slaughterhouses

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    Small-scale slaughterhouses (SHs) face many challenges, not least due to the requirements of food safety legislation. Food business operators' (FBOs') own-check system is very important for food safety, but its proper implementation can be quite difficult and laborious for small-scale SHs. In the European Union, the importance not only of food safety but also facilitation of local food production, including small-scale slaughtering, is highlighted. The aim of our study was to assess compliance with legislation of own-check systems, including six own-check programmes and HACCP, in small-scale SHs. The FBOs' opinions of the implementation of own-check systems were also sought to elucidate possible obstacles in implementation. Our results showed that the best compliance in own-check programmes was achieved in temperature of storage rooms and traceability. FBOs also evaluated these programmes as necessary. However, FBOs' perceived necessity of own-check programmes did not always lead to compliance, as was the case with labelling and HACCP. Instead, in HACCP laboriousness and compliance showed a negative correlation (p <0.05). In addition to laboriousness, costs of own-check programmes, specifically concerning microbiological sampling requirements, appeared to influence compliance, with many of the small-scale SHs poorly following sampling requirements. FBOs also noted the high costs of the non-edible by-product programme. Moreover, the results show that official veterinarians' assessment of compliance was significantly higher than that of the researcher, which warrants further investigation. This study reveals that many small-scale SHs in Finland struggle with food safety requirements. Amendments of some of the requirements to ease the burden of FBOs are proposed. HACCP in particular is suggested to be simplified. In addition, ways to improve food safety and official control in small-scale SHs are discussed.Peer reviewe

    The Chandrasekhar limit for quark stars

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    The Chandrasekhar limit for quark stars is evaluated from simple energy balance relations, as proposed by Landau for white dwarfs or neutron stars. It has been found that the limit for quark stars depends on, in addition to the fundamental constants, the Bag constant.Comment: LateX fil

    Average-Case Optimal Approximate Circular String Matching

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    Approximate string matching is the problem of finding all factors of a text t of length n that are at a distance at most k from a pattern x of length m. Approximate circular string matching is the problem of finding all factors of t that are at a distance at most k from x or from any of its rotations. In this article, we present a new algorithm for approximate circular string matching under the edit distance model with optimal average-case search time O(n(k + log m)/m). Optimal average-case search time can also be achieved by the algorithms for multiple approximate string matching (Fredriksson and Navarro, 2004) using x and its rotations as the set of multiple patterns. Here we reduce the preprocessing time and space requirements compared to that approach

    A comparative analysis of meat inspection data as an information source of the health and welfare of broiler chickens based on Finnish data

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    The comprehensive, reliable, and comparable meat inspection (MI) data of broiler chickens (i.e. broilers) are essential for the monitoring and surveillance of broiler health and welfare at the national and European Union (EU) levels. We compared the condemnation causes issued to broiler carcasses during MI in four large Finnish broiler slaughterhouses (SHs) by investigating the similarities and differences between local MI instructions used in the SHs. The way in which MI condemnations were recorded in the Finnish Food Authority's (FFA's) MI statistics were also explored. We additionally analysed the FFA's official MI data from the 2015-2019 period. The study showed that the MI criteria used in the SHs differed from one another regarding how severe or extensive a broiler defect or disease must be to cause condemnation during MI. In Finland, the annual total condemnation prevalence of whole broilers varied between 2.6% and 4.8% in 2015-2019, and a significant difference was observed between the SHs' monthly total condemnation prevalences, except in two SH pairs. Mistakes in recording the FFA's MI statistics and differences in the SH operators' reasons to reject broilers from the food chain affect the comparability of the condemnation prevalences between the SHs. Only half of the SHs partially condemned broiler carcasses and collected data concerning these condemnations. Cellulitis (0.3-1.0%), ascites (0.3-0.4%), and body cavity disorders (0.2-0.3%) were the most common causes for condemning whole broiler carcasses in 2015-2019. The MI data can be used for monitoring and surveillance purposes only once the differences between the SH data and data reliability are known. Although the harmonization of all condemnation causes is impossible, harmonizing the condemnations of carcasses with diseases that most threaten broiler health and welfare and cause the largest economic losses would be important.Peer reviewe
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