1,751,668 research outputs found
Calcareous nannofossils of ODP sites 177-1088 and 177-1090
No full textDuring ODP Leg 177, a Miocene to Pliocene calcareous nannofossil record was recovered at Sites 1088 and 1090. Site 1088, located at 41°8'S, shows a continuous middle-upper Miocene to Pliocene carbonate sequence that was deposited at relatively high sedimentation rates (Shipboard Scientific Party, 1999a, doi:10.2973/odp.proc.ir.177.103.1999). Moreover, Site 1088 proved suitable for calcareous nannofossil analysis as a means to improve the biostratigraphy at this southern latitude.
Site 1090 was drilled at 42°54'S; a tephra layer marks a significant disconformity at the Miocene/Pliocene boundary of this sequence (Shipboard Scientific Party, 1999b, doi:10.2973/odp.proc.ir.177.105.1999). Although nannofossil assemblages are poorly preserved at this site (Shipboard Scientific Party, 1999b), they may help in determining the age of the disconformity and its paleoceanographic significance
(Table 2) Depth-age control points of ODP Site 177-1090
No full textAt Ocean Drilling Program (ODP) Site 1090 on the Agulhas Ridge (subantarctic South Atlantic) benthic foraminiferal stable isotope records span the late Oligocene through the early Miocene (25~16 Ma) at a temporal resolution of ~10 kyr. In the same time interval a magnetic polarity stratigraphy can be unequivocally correlated to the geomagnetic polarity timescale (GPTS), thereby providing secure correlation of the isotope record to the GPTS. On the basis of the isotope-magnetostratigraphic correlation we provide refined age calibration of established oxygen isotope events Mi1 through Mi2 as well as several other distinctive isotope events. Our data suggest that the d18O maximum commonly associated with the Oligocene/Miocene (O/M) boundary falls within C6Cn.2r (23.86 Ma). The d13C maximum coincides, within the temporal resolution of our record, with C6Cn.2n/r boundary and hence to the O/M boundary. Comparison of the stable isotope record from ODP Site 1090 to the orbitally tuned stable isotope record from ODP Site 929 across the O/M boundary shows that variability in the two records is very similar and can be correlated at and below the O/M boundary. Site 1090 stable isotope records also provide the first deep Southern Ocean end-member for reconstructions of circulation patterns and late Oligocene to early Miocene climate change. Comparison to previously published records suggests that basin to basin carbon isotope gradients were small or nonexistent and are inconclusive with respect to the direction of deep water flow. Oxygen isotope gradients between sites suggest that the deep Southern Ocean was cold in comparison to the North Atlantic, Indian, and the Pacific Oceans. Dominance of cold Southern Component Deep Water at Site 1090, at least until 17 Ma, suggests that relatively cold circumpolar climatic conditions prevailed during the late Oligocene and early Miocene. We believe that a relatively cold Southern Ocean reflects unrestricted circumpolar flow through the Drake Passage in agreement with bathymetric reconstructions
Magnetic-, isotopic-, and biostratigraphies in ODP Hole 177-1090
No full textAt Ocean Drilling Program (ODP) Site 1090 (lat 42°54.8'S, long 8°54.0'E) located in a water depth of 3702 m on the Agulhas Ridge in the sub-Antarctic South Atlantic, ~300 m of middle Eocene to middle Miocene sediments were recovered with the advanced piston corer (APC) and the extended core barrel (XCB). U-channel samples from the 70-230 meters composite depth (mcd) interval provide a magnetic polarity stratigraphy that is extended to 380 mcd by shipboard whole-core and discrete sample data. The magnetostratigraphy can be interpreted by the fit of the polarity-zone pattern to the geomagnetic polarity time scale (GPTS) augmented by isotope data and bioevents with documented correlation to the GPTS. Three normal-polarity subchrons (C5Dr.1n, C7Ar.1n, and C13r.1n), not included in the standard GPTS, are recorded at Site 1090. The base of the sampled section is correlated to C19n (middle Eocene), although the interpretation is unclear beyond C17r. The top of the sampled section is correlated to C5Cn (late early Miocene), although, in the uppermost 10 m of the sampled section, a foraminifer (Globorotalia sphericomiozea) usually associated with the Messinian and early Pliocene has been identified. 87Sr/86Sr, d13C, and d18O values measured on foraminifera, including the d18O and d13C shifts close to the Eocene/Oligocene boundary, support the correlation to the GPTS. For the interval spanning the Oligocene/Miocene boundary, benthic d13C, d18O, and 87Sr/86Sr records from Site 1090 can be correlated to isotope records from ODP Site 929 (Ceara Rise), providing support for the recently-published Oligocene/Miocene boundary age (22.92 Ma) of Shackleton et al
Revised geomagnetic polarity timescale for the late Oligocene to early Miocene of ODP Site 177-1090
No full textAt Ocean Drilling Program (ODP) Site 1090 (subantarctic South Atlantic), benthic foraminiferal stable isotope data (from Cibicidoides and Oridorsalis) span the late Oligocene through early Miocene (~24-16 Ma) at a temporal resolution of ~5 ky. Over the same interval, a magnetic polarity stratigraphy can be unequivocally correlated to the geomagnetic polarity time scale (GPTS), thereby providing direct correlation of the isotope record to the GPTS. In an initial age model, we use the newly derived age of the Oligocene/Miocene (O/M) boundary of 23.0 Ma of Shackleton et al. (2000, doi:10.1130/0091-7613(2000)282.0.CO;2), revised to the new astronomical calculation (La2003) of Laskar et al (2004, doi:10.1016/j.icarus.2004.04.005) to recalculate the spline ages of Cande and Kent (1995, doi:10.1029/94JB03098). We then tune the Site 1090 dekta18O record to obliquity using La2003. In this manner, we are able to refine the ages of polarity chrons C7n through C5Cn.1n. The new age model is consistent, within one obliquity cycle, with previously tuned ages for polarity chrons C7n through C6Bn from Shackleton et al. (2000) when rescaled to La2003. The results from Site 1090 provide independent evidence for the revised age of the Oligocene/Miocene boundary of 23.0 Ma. For early Miocene polarity chrons C6AAr through C5Cn, our obliquity-scale age model is the first to allow a direct calibration to the GPTS. The new ages are generally within one obliquity cycle of those obtained by rescaling the Cande and Kent (1995) interpolation using the new age of the O/M boundary (23.0 Ma) and the same middle Miocene control point (14.8 Ma) used by Cande and Kent (1995)
Standardien SFS-EN 1090-1+A1 ja SFS-EN 1090-2+A1 käyttöönotto ja CE merkintä teräsrakenteissa
Get PDFTeräksestä ja alumiinista valmistettavien rakennustuotteiden standardi SFS-EN 1090-1 tulee harmonisoituna standardina voimaan Euroopassa 1.7.2014. Siihen kuuluu myös viitestandardit SFS-EN 1090-2 ja SFS-EN 1090-3. SFS-EN 1090-1 käsittelee teräs- ja alumiinirakenteiden toteutusta ja rakenteellisten kokoonpanojen vaatimuksia sekä CE-merkintää ja sen edellytyksiä. SFS-EN 1090-2 käsittelee teräsrakenteiden teknisiä vaatimuksia. SFS-EN 1090-3 käsittelee alumiinirakenteiden teknisiä vaatimuksia.
Tämä työ on tehty RR Site Service Oy:lle. RR Site Service Oy on Eurajoella toimiva yritys, jonka toiminta-ajatus on tarjota erilaisiin laivanrakennus-, offshore- ja teollisuusprojekteihin projektinjohto, tarkastuspalveluita ja muita projekteihin liittyviä konsultointipalveluita. Lisäksi toimintaan tulevat mukaan uudelleen käynnistettävät toiminnot: laite-, putkisto- ja teräsrakenneasennukset ja urakointi. Tarkoituksena oli ottaa selvää standardin SFS-EN 1090-1 ja viitestandardin SFS-EN 1090-2 vaikutuksesta alihankintana teräsrakenteita valmistavaan yritykseen, sekä laatia yrityskohtainen FPC-manuaali laadunvalvonnalle ja CE-merkinnälle standardin sekä viitestandardin soveltamisalueilla. Tämän työn pohjalta yrityksen on tarkoitus hakea sertifiointia standardille ja oikeutta kiinnittää CE-merkintä valmistamiinsa kokoonpanoihin
Standardin EN 1090 vaikutukset suodattimen jalustarakenteen suunnitteluprosessiin
Get PDFInsinöörityö on laadittu Industri Textil Job Oy:lle. Työn lähtökohtana on kantaville teräsrakenteille pakolliseksi tullut CE-merkintä standardin EN 1090 perusteella. Työn tarkoituksena oli selvittää, kuuluvatko yrityksen toimittamien suodatinyksiköiden kantavat jalustarakenteet standardin EN 1090 soveltamisalan piiriin ja mitä muutoksia standardi tuo jalustan rakenteelliseen suunnitteluun ja laskentaan sekä verrata standardin vaatimuksia yrityksen nykymenettelyihin.
Työssä tutkittiin erityisesti standardeja EN 1090-1 ja EN 1090-2, niiden viitestandardeja ja soveltuvia eurokoodeja sekä aiheeseen liittyviä julkaisuja, jotta nykyistä suunnitteluprosessia voitiin arvioida ja vaadittavat toimenpiteet määrittää. Rakenteen luokittelu standardin mukaisesti edellytti tutustumista EU:n rakennusteollisuutta koskevaan rakennustuoteasetukseen ja Suomen lainsäädäntöön maankäyttö- ja rakennuslain osalta sekä lyhyesti konedirektiiviin. Lisäksi tutustuttiin eurokoodimitoitukseen, johon standardi EN 1090 perustuu.
Insinöörityön tuloksena on määritetty tärkeimmät tekijät, joilla saavutetaan valmius suorittaa standardin EN 1090 mukaista rakenteellista suunnittelua. Etenkin käytettyjen työmenetelmien perusteella voitiin määrittää uudet dokumentit laatimalla suunnitteluseloste ja toteutuseritelmä täydentämään suunnitteluprosessia. Tuloksena laadittujen suunnitteluselosteen ja toteutuseritelmän perusteella saavutettiin valmius suorittaa EN 1090:n mukaista suunnittelua.
Päätelminä voidaan todeta, että laadituilla dokumenteilla parannetaan projektikohtaisen dokumentaation laatua ja ne toimivat osoituksena standardin EN 1090 mukaisesta suunnittelusta, kun ne sisältävät yksityiskohtaista tietoa valmistusvaatimuksista ja suunnittelussa käytetyistä menettelyistä. Työssä tutkittujen lähteiden perusteella ei lopputuloksena kuitenkaan voida absoluuttisesti sanoa, että suodattimen jalustaan tulisi soveltaa CE-merkinnässä standardia EN 1090. Luokittelu on suodattimen jalustan tapauksessa hyvin tulkinnanvaraista, koska jalustarakennetta käytetään kiinteänä osana konetta, vaikka se sijaitsisi standardin EN 1090 mukaisessa rakennuskohteessa.This Bachelor´s thesis was made for Industri Textil Job Oy. The purpose of the thesis was to examine the CE marking of load-bearing steel structures which has become mandatory along with the standard EN 1090. The objective of this thesis was to clarify if the base structures of filtration units supplied by the company come under the scope of standard EN 1090 and to find out what changes the standard carries with it for the company’s current structural design and calculus.
Especially, standards EN 1090-1 and EN 1090-2 were studied in this thesis together with their normative references, Eurocode standards and relevant publications so that Industri Textil Job Oy’s design process could be evaluated and the required procedures could be defined as well. The classification of the structure according to EN 1090 demanded getting acquainted with construction product regulation concerning the construction industry in the European Union, the Finnish land use and building act and briefly the machinery directive.
As a result of this thesis, the main factors have been defined to achieve the ability to carry out structural design in accordance with standard EN 1090. Due to the used methods of study, the design process could be improved with the drawn up documents such as execution specification and design brief.
In conclusion, the drawn up documents can be found to improve the project documentation and they act as a proof of EN 1090 used in the process, particularly when they contain detailed information of the manufacturing requirements and procedures used in the design process. Despite the studied source materials, however, it cannot be said with certainty that EN 1090 should be applied to the CE-marking on filtration units’ base structures. The classifications of such base structures are open to interpretations because they are both structures integrated to machinery and load-bearing components
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Analyzing Aircraft Surveillance Signal Quality at the 1090 Megahertz Radio Frequency
No full textDue to the increasing demands for real-time air traffic monitoring, the 1090 megahertz radio frequency has become the most utilized communication channel for aircraft surveillance purposes. Several services are using the radio frequency at the same time, which are Mode A/C communications and Mode S communications. These different types of communications are not coordinated, meaning that the quality of a communication channel can deteriorate with the increasing number of aircraft in the airspace. This deterioration may further worsen with the increasing number of aircraft that comply with the Automatic Dependent Surveillance-Broadcast requirement, which is implemented based on Mode S Extended Squitter. In this paper, we conduct experiments to determine the quality of 1090 megahertz radio frequency by analyzing the low-level signals using an open-source software-defined radio. First, we implement the demodulation of Mode A/C and Mode S signals from the raw in-phase and quadrature signals with a high sampling rate. Then, several methods are employed to study the occupancy of the communication channel and the garbling severity of the signals, as well as the error rate in ADS-B signals. All results show that the radio frequency is experiencing high communication load during day time air traffic operations. The results also suggest a need for a major redesign of the aircraft surveillance system in the future due to the current inefficient utilization of this radio frequency.Virtual/online event due to COVID-19Control & SimulationControl & Operation
SFS-EN 1090 STANDARDIN SERTIFIOINNIN TOTEUTUS
Get PDFOpinnäytetyö käsittelee kantavien teräsrakenteiden valmistuksen sertifiointia SFS-EN 1090 standar-din mukaan ja tämän toteutusta. Työssä selvitettiin lisäksi SFS-EN 1090 standardin määrittämät vaatimukset ja niiden toteuttaminen Salmen Metalli Oy:ssä.
Työn aihepiiriin kuuluu pohdintaa sertifikaatin eduista yritykselle ja sen asiakkaille. Opinnäytetyössä käytiin läpi sertifioinnin dokumentointi ja yrityksen toiminnan muokkaaminen. Sertifikaatin vaatimiin dokumentoinnin osalta kuuluivat muun muassa FPC-manuaali, vaatimuksenmukaisuusvakuutus, hitsausohjeet, materiaali- ja ainestodistukset, validointitodistukset sekä pätevyydet.
Työ toteutettiin perehtymällä SFS-EN 1090-1 ja SFS-EN 1090-2 standardeihin ja niiden vaatimuksiin sekä tutkimalla aiempia kokemuksia sertifiointiin liittyen. Opinnäytetyössä otettiin huomioon toimet, jotka tulee huomioida erityisesti Salmen Metalli Oy:n toiminnassa. Opinnäytetyö ottaa myös kantaa päivitetyn standardin teknisen osan vaatimuksiin.The thesis deals with the certification of the production of structural steel constructions according to the SFS-EN 1090 standard and its implementation. In addition, the requirements of the SFS-EN 1090 standard and their implementation in Salmen Metalli Oy were analyzed.
The subject of the thesis is a reflection on the benefits of the certificate to the company and its customers. The thesis was used to review certification documentation and modify the company's operations. The documentation required for the certificate included the FPC manual, declaration of conformity, welding procedure specifications, material certificates, validation certificates and qualifi-cations.
The work was carried out by familiarizing with the standards and requirements of SFS-EN 1090-1 and SFS-EN 1090-2, as well as by examining previous experience in certification. The thesis took into account the activities that should be taken into consideration especially in the operations of Salmen Metalli Oy. The thesis also comments on the requirements of the technical part of the up-dated standard
- …
