732 research outputs found
Optimasi Karakteristik Fungsional Minyak Atsiri Jahe Merah(Zingiber officanalte var. rubrum) pada Brownies Substitusi Tepung Ubi Ungu (Ipomoea batatas L.)sebagai Sumber Antioksidan
Tingginya kesadaran akan pentingnya kesehatan menyebabkan perubahan pola makan masyarakat cenderung lebih memilih makanan alami dan sehat yang sekaligus berfungsi mencegah atau mengobati penyakit yang disebut sebagai pangan fungsional. Salah satu produk fungsional bakery yang paling populer adalah brownies. Brownies komersial yang beredar di pasaran belum ada yang sekaligus berfungsi sebagai pangan fungsional. Salah satu alternatif untuk menjadikan brownies sebagai salah satu pangan fungsional adalah dengan subsitusi menggunakan tepung ubi jalar ungu dan penambahan minyak atsiri jahe merah sebagai sumber antioksidan. Penelitian ini bertujuan untuk mengetahui aktivitas antioksidan dan senyawa aktif, peneriman panelis, serta mengetahui sifat fisik dan kimia terhadap brownies kukus substitusi tepung ubi ungu dengan penambahan minyak atsiri. Desain penelitian yang digunakan Rancangan Acak Lengkap dengan satu faktor yang mempengaruhi variasi penambahan minyak atsiri jahe merah dengan konsentrasi masing masing 0,05%; 0,10%; 0,15%; 0,20%; dan 0,25%. Hasil penelitian menunjukan aktivitas antioksidan IC50 yang diperoleh pada brownies substitusi tepung ubi ungu dengan penambahan minyak atsiri jahe merah berkisar antara 957.74 ppm sampai 450.24 ppm. Komponen senyawa pada brownies substitusi tepung ubi ungu dengan penambahan minyak atsiri jahe merah antara lain adalah Levoglukosan, Asam Palmitat, Asam Oleat, Theobromin, Asam Stearat, Asam Laurat, dan HMF. Berdasarkan uji organoleptik brownies substitusi tepung ubi ungu dengan penambahan minyak atsiri jahe merah terbaik adalah brownis dengan konsentrasi penambahan 0,05%. Kata kunci : Brownies, Minyak atsiri, Antioksidan, Senyawa fungsiona
Investigating the medium range order in amorphous Ta<sub>2</sub>O<sub>5</sub> coatings
Ion-beam sputtered amorphous heavy metal oxides, such as Ta2O5, are widely used as the high refractive index layer of highly reflective dielectric coatings. Such coatings are used in the ground based Laser Interferometer Gravitational-wave Observatory (LIGO), in which mechanical loss, directly related to Brownian thermal noise, from the coatings forms an important limit to the sensitivity of the LIGO detector. It has previously been shown that heat-treatment and TiO2 doping of amorphous Ta2O5 coatings causes significant changes to the levels of mechanical loss measured and is thought to result from changes in the atomic structure. This work aims to find ways to reduce the levels of mechanical loss in the coatings by understanding the atomic structure properties that are responsible for it, and thus helping to increase the LIGO detector sensitivity. Using a combination of Reduced Density Functions (RDFs) from electron diffraction and Fluctuation Electron Microscopy (FEM), we probe the medium range order (in the 2-3 nm range) of these amorphous coatings
Использование процедуры а для оценивания компетентности аккредитованных лабораторий, участвующих в сличениях
Investigation of positive streamers by double-pulse experiments, effects of repetition rate and gas mixture
A Cryogenic Silicon Interferometer for Gravitational-wave Detection
The detection of gravitational waves from compact binary mergers by LIGO has opened the era of gravitational wave astronomy, revealing a previously hidden side of the cosmos. To maximize the reach of the existing LIGO observatory facilities, we have designed a new instrument that will have 5 times the range of Advanced LIGO, or greater than 100 times the event rate. Observations with this new instrument will make possible dramatic steps toward understanding the physics of the nearby universe, as well as observing the universe out to cosmological distances by the detection of binary black hole coalescences. This article presents the instrument design and a quantitative analysis of the anticipated noise floor
Effect of elevated substrate temperature deposition on the mechanical losses in tantala thin film coatings
Brownian thermal noise in dielectric multilayer coatings limits the sensitivity of current and future interferometric gravitational wave detectors. In this work we explore the possibility of improving the mechanical losses of tantala, often used as the high refractive index material, by depositing it on a substrate held at elevated temperature. Promising results have been previously obtained with this technique when applied to amorphous silicon. We show that depositing tantala on a hot substrate reduced the mechanical losses of the as-deposited coating, but subsequent thermal treatments had a larger impact, as they reduced the losses to levels previously reported in the literature. We also show that the reduction in mechanical loss correlates with increased medium range order in the atomic structure of the coatings using x-ray diffraction and Raman spectroscopy. Finally, a discussion is included on our results, which shows that the elevated temperature deposition of pure tantala coatings does not appear to reduce mechanical loss in a similar way to that reported in the literature for amorphous silicon; and we suggest possible future research directions
Astrophysically Triggered Searches for Gravitational Waves: Status and Prospects
In gravitational-wave detection, special emphasis is put onto searches that
focus on cosmic events detected by other types of astrophysical observatories.
The astrophysical triggers, e.g. from gamma-ray and X-ray satellites, optical
telescopes and neutrino observatories, provide a trigger time for analyzing
gravitational wave data coincident with the event. In certain cases the
expected frequency range, source energetics, directional and progenitor
information is also available. Beyond allowing the recognition of gravitational
waveforms with amplitudes closer to the noise floor of the detector, these
triggered searches should also lead to rich science results even before the
onset of Advanced LIGO. In this paper we provide a broad review of LIGO's
astrophysically triggered searches and the sources they target
First LIGO search for gravitational wave bursts from cosmic (super)strings
We report on a matched-filter search for gravitational wave bursts from
cosmic string cusps using LIGO data from the fourth science run (S4) which took
place in February and March 2005. No gravitational waves were detected in 14.9
days of data from times when all three LIGO detectors were operating. We
interpret the result in terms of a frequentist upper limit on the rate of
gravitational wave bursts and use the limits on the rate to constrain the
parameter space (string tension, reconnection probability, and loop sizes) of
cosmic string models.Comment: 11 pages, 3 figures. Replaced with version submitted to PR
Gravitational Waves From Known Pulsars: Results From The Initial Detector Era
We present the results of searches for gravitational waves from a large selection of pulsars using data from the most recent science runs (S6, VSR2 and VSR4) of the initial generation of interferometric gravitational wave detectors LIGO (Laser Interferometric Gravitational-wave Observatory) and Virgo. We do not see evidence for gravitational wave emission from any of the targeted sources but produce upper limits on the emission amplitude. We highlight the results from seven young pulsars with large spin-down luminosities. We reach within a factor of five of the canonical spin-down limit for all seven of these, whilst for the Crab and Vela pulsars we further surpass their spin-down limits. We present new or updated limits for 172 other pulsars (including both young and millisecond pulsars). Now that the detectors are undergoing major upgrades, and, for completeness, we bring together all of the most up-to-date results from all pulsars searched for during the operations of the first-generation LIGO, Virgo and GEO600 detectors. This gives a total of 195 pulsars including the most recent results described in this paper.United States National Science FoundationScience and Technology Facilities Council of the United KingdomMax-Planck-SocietyState of Niedersachsen/GermanyAustralian Research CouncilInternational Science Linkages program of the Commonwealth of AustraliaCouncil of Scientific and Industrial Research of IndiaIstituto Nazionale di Fisica Nucleare of ItalySpanish Ministerio de Economia y CompetitividadConselleria d'Economia Hisenda i Innovacio of the Govern de les Illes BalearsNetherlands Organisation for Scientific ResearchPolish Ministry of Science and Higher EducationFOCUS Programme of Foundation for Polish ScienceRoyal SocietyScottish Funding CouncilScottish Universities Physics AllianceNational Aeronautics and Space AdministrationOTKA of HungaryLyon Institute of Origins (LIO)National Research Foundation of KoreaIndustry CanadaProvince of Ontario through the Ministry of Economic Development and InnovationNational Science and Engineering Research Council CanadaCarnegie TrustLeverhulme TrustDavid and Lucile Packard FoundationResearch CorporationAlfred P. Sloan FoundationAstronom
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